Language：English   Publishing type：Research paper (scientific journal)  

DOI： doi.org/10.1016/j.dib.2018.02.063

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1111/brv.12286

Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

Recently, we found that resident myogenic stem satellite cells up-regulate a multi-functional secreted protein, semaphorin 3A (Sema3A), exclusively at the early- differentiation phase in response to muscle injury; however, its physiological significance is still unknown. Here we show that Sema3A impacts slow-twitch fiber generation through a signaling pathway, cell-membrane receptor (neuropilin2-plexinA3) → myogenin-myocyte enhancer factor 2D (MEF2D) → slow myosin heavy chain. This novel axis was found by small interfering RNA (siRNA)-transfection experiments in myoblast cultures, which also revealed an additional element that Sema3A-neuropilin1/plexinA1, A2 may enhance slow-fiber formation by activating signals that inhibit fast-myosin expression. Importantly, satellite cell-specific Sema3A conditional-knockout adult mice (Pax7CreERT2-Sema3Aflox activated by tamoxifen-i.p. injection) provided direct in vivo evidence for the Sema3A-driven program, by showing that slow-fiber generation and muscle endurance were diminished after repair from cardiotoxin-injury of gastrocnemius muscle. Overall, the findings highlight an active role for satellite cell-secreted Sema3A ligand as a key “commitment factor” for the slow-fiber population during muscle regeneration. Results extend our understanding of the myogenic stem-cell strategy that regulates fiber-type differentiation and is responsible for skeletal muscle contractility, energy metabolism, fatigue resistance, and its susceptibility to aging and disease.

DOI： 10.1002/stem.2639

Language：English   Publishing type：Research paper (scientific journal)  

Our previous studies demonstrated that an 8-week intake of 5% (w/w) apple polyphenol (APP) in the diet improves muscle endurance of young-adult rats. In order to identify a lower limit of the dietary contribution of APP to the effect, the experiments were designed for lower-dose supplementation (8-week feeding of 0.5% APP in AIN-93G diet) to 12-week-old male Sprague-Dawley rats. Results clearly showed that the 0.5% APP diet significantly up-regulates slower myosin-heavy-chain (MyHC) isoform ratios (IIx and IIa relative to total MyHC) and myoglobin expression in lower hind-limb muscles examined (P < 0.05). There was a trend to increased fatigue resistance detected from measurements of relative isometric planter-flexion force torque generated by a stimulus train delivered to the tibial nerve (F (98, 1372) = 1.246, P = 0.0574). Importantly, there was no significant difference in the animal body-phenotypes or locomotor activity shown as total moving distance in light and dark periods. Therefore, the present study encourages the notion that even low APP-intake may increase the proportions of fatigue-resistant myofibers, and has promise as a strategy for modifying performance in human sports and improving function in age-related muscle atrophy.

DOI： 10.1111/asj.12655

Language：English   Publishing type：Research paper (scientific journal)  

This article provides in vitro phenotypical data to show that APOBEC2, a member of apoB mRNA editing enzyme, catalytic polypeptide-like family, may implicate in self-renewal functions of myogenic stem satellite cells, namely in the re-establishment of quiescent status after activation and proliferation of myoblasts in single-myofiber culture.

DOI： 10.1016/j.dib.2017.03.051

Language：English   Publishing type：Research paper (scientific journal)  

Recently we found that the deficiency of APOBEC2, a member of apoB mRNA editing enzyme, catalytic polypeptide-like family, leads to a diminished muscle mass and increased myofiber with centrally-located nuclei known as dystrophic phenotypes. APOBEC2 expression is predominant in skeletal and cardiac muscles and elevated exclusively at the early-differentiation phase of wild-type (WT) myoblast cultures; however the physiological significance is still un-known. Here we show that APOBEC2 is a key negative regulator of myoblast differentiation in muscle regeneration. APOBEC2-knockout (A2KO) mice myoblast cultures displayed a normal morphology of primary myotubes along with earlier increase in fusion index and higher expression levels of myosin heavy chain (MyHC), myogenin and its cooperating factor MEF2C than WT myoblasts. Similar response was observable in APOBEC2-knockdown cultures of WT myoblasts that were transfected with the specific siRNA at the differentiation phase (not proliferation phase). Importantly, cardiotoxin-injured A2KO gastrocnemius muscle provided in vivo evidence by showing larger up-regulation of neonatal MyHC and myogenin and hence earlier regeneration of myofiber structures with diminished cross-sectional areas and minimal Feret diameters. Therefore, the findings highlight a promising role for APOBEC2 in normal progression of regenerative myogenesis at the early-differentiation phase upon muscle injury.

DOI： 10.1016/j.biocel.2017.02.005

Language：English   Publishing type：Research paper (scientific journal)  

Regenerative mechanisms that regulate intramuscular motor innervation are thought to reside in the spatiotemporal expression of axon-guidance molecules. Our previous studies proposed an unexplored role of resident myogenic stem cell (satellite cell)-derived myoblasts as a key presenter of a secreted neural chemorepellent semaphorin 3A (Sema3A); hepatocyte growth factor (HGF) and basic fibroblast growth factor (FGF2) triggered its expression exclusively at the early-differentiation phase. In order to advance this concept, the present study described that transmembrane heparan/chondroitin-sulfate proteoglycans syndecan-2, 4 may be the plausible receptor candidates for HGF and FGF2 to signal Sema3A expression. Results showed that mRNA expression of syndecan-2, 4 was abundant (two-magnitude higher than syndecan-1, 3) in early-differentiated myoblasts and their in vitro knock-down diminished the HGF/FGF2-induced expression of Sema3A down to a baseline level. Pre-treatment with heparitinase and chondroitinase ABC decreased the HGF and FGF2 responses, respectively in non-knock-down cultures, supporting a possible model that HGF and FGF2 may bind to heparan and chondroitin sulfate chains of syndecan-2, 4 to signal Sema3A expression. The findings, therefore, extend our understanding that HGF/FGF2-syndecan-2, 4 association may stimulate a burst of Sema3A secretion by myoblasts recruited to the site of muscle injury; this would ensure a coordinated delay in the attachment of motoneuron terminals onto fibers early in muscle regeneration, and thus synchronize the recovery of muscle-fiber integrity and the early resolution of inflammation after injury with reinnervation toward functional recovery.

DOI： 10.14814/phy2.12553

Language：English   Publishing type：Research paper (scientific journal)  

A recent study demonstrated a positive effect of apple polyphenol (APP) intake on muscle endurance of young-adult animals. While an enhancement of lipid metabolism may be responsible, in part, for the improvement, the contributing mechanisms still need clarification. Here we show that an 8-week intake of 5% (w/w) APP in the diet, up-regulates two features related to fiber type: the ratio of myosin heavy chain (MyHC) type IIx/IIb and myoglobin protein expression in plantaris muscle of 9-week-old male Fischer F344 rats compared to pair-fed controls (P < 0.05). Results were demonstrated by our SDS-PAGE system specialized for MyHC isoform separation and western blotting of whole muscles. Animal-growth profiles (food intake, body-weight gain, and internal-organ weights) did not differ between the control and 5% APP-fed animals (n = 9/group). Findings may account for the increase in fatigue resistance of lower hind limb muscles, as evidenced by a slower decline in the maximum isometric planter-flexion torque generated by a 100-s train of electrical stimulation of the tibial nerve. Additionally, the fatigue resistance was lower after 8 weeks of a 0.5% APP diet than after 5% APP, supporting an APP-dose dependency of the shift in fiber-type composition. Therefore, the present study highlights a promising contribution of dietary APP intake to increasing endurance based on fiber-type composition in rat muscle. Results may help in developing a novel strategy for application in animal sciences, and human sports and age-related health sciences.

DOI： 10.1371/journal.pone.0134303

Language：English   Publishing type：Research paper (scientific journal)  

Regenerative intramuscular motor-innervation is thought to reside in the spatiotemporal expression of axon-guidance molecules. Our previous studies showed that resident myogenic stem cells, satellite cells, up-regulate a secreted neural-chemorepellent semaphorin 3A (Sema3A) during the early-differentiation period, in response to hepatocyte growth factor (HGF) elevated in injured muscle. However, a paracrine source of the HGF release is still unknown. Very recently, we proposed a possible contribution of anti-inflammatory macrophages (CD206-positive M2) by showing that M2 cells infiltrate predominantly at the early-differentiation phase (3-5 days post-injury) and produce/secrete large amounts of HGF. In understanding this concept, however, there still remains a critical need to examine if phagocytotic pro-inflammatory macrophages (CD86-positive M1), another activated-phenotype still present at the early-differentiation phase concerned, produce HGF upon muscle injury. The current immunocytochemical study demonstrated that the HGF expression is negative for M1 prepared from cardiotoxin-injured tibialis anterior muscle at day-5, in contrast to the intense fluorescent-signal of M2 served as a positive control. This supplementary result advances our understanding of a spatiotemporal burst of HGF secretion from M2 populations (not M1) to impact Sema3A expression, which ensures a coordinated delay in attachment of motoneuron terminals onto damaged and generating fibers during early phase of muscle regeneration.

DOI： 10.1111/asj.12264

Language：English   Publishing type：Research paper (international conference proceedings)  

Successful regeneration and remodeling of neuromuscular connections are critical for restoring functional properties of muscle fiber contractility. While the spatiotemporal regulatory mechanisms coordinating these processes (moto-neuritogenesis) with myogenesis itself remain unclear, various neural factors including attractive and repulsive axon-guidance cue ligands may be involved. Our previous studies proposed a heretofore unexplored role of resident myogenic stem cell (satellite cell)-derived myoblasts as a key presenter of a secreted neural chemorepellent semaphorin 3A (Sema3A); hepatocyte growth factor (HGF) triggered its expression exclusively at the early-differentiation phase. In order to verify this concept, the present study was designed to clarify a paracrine source of HGF release. In vitro experiments demonstrated that activated anti-inflammatory macrophages (CD206-positive M2) produce HGF and thereby promote myoblast chemoattraction and Sema3A expression. Media from pro-inflammatory macrophage cultures (M1) did not show any significant effect. M2 also enhanced the expression of myoblast-differentiation markers in culture, and infiltrated predominantly at the early-differentiation phase (3-5 d post-injury); M2 were confirmed to produce HGF as monitored by in vivo/ex vivo immunocytochemistry of CD11b/CD206/HGF-positive cells and by HGF in situ hybridization of cardiotoxin- or crush-injured tibialis anterior muscle, respectively. Findings, therefore, encourage the idea that M2 contribute to spatiotemporal up-regulation of extracellular Sema3A concentrations by producing HGF that, in turn, stimulates a burst of Sema3A secretion by myoblasts that are recruited to site of injury. This model may ensure a coordinated delay in re-attachment of motoneuron terminals onto damaged fibers early in muscle regeneration, and thus synchronize the recovery of muscle-fiber integrity after injury.
(Key Words: Mouse muscle, Activated macrophages, Hepatocyte growth factor (HGF), Semaphorin 3A (Sema3A), Regenerative moto-neuritogenesis)

Language：English   Publishing type：Research paper (international conference proceedings)  

Successful regeneration and remodeling of neuromuscular connections are critical for restoring functional properties of muscle fiber contractility. While the spatiotemporal regulatory mechanisms coordinating these processes (moto-neuritogenesis) with myogenesis itself remain unclear, various neural factors including attractive and repulsive axon-guidance cue ligands and their membrane receptors may be involved. Our previous studies proposed a heretofore unexplored role of resident myogenic stem cell (satellite cell)-derived myoblasts as a key presenter of a secreted neural chemorepellent semaphorin 3A (Sema3A); hepatocyte growth factor (HGF) triggered its expression exclusively at the early-differentiation phase (Tatsumi et al., 2009; Do et al., 2011, 2012; Sato et al., 2013; Suzuki et al., 2013). In order to verify this concept, the present study was designed to clarify a paracrine source of HGF release. In vitro experiments demonstrated that activated anti-inflammatory macrophages (CD206-positive M2) produce HGF and thereby promote myoblast chemoattraction and Sema3A expression. Media from pro-inflammatory macrophage cultures (CD86-positive M1) did not show any significant effect. M2 infiltrated predominantly at the early-differentiation phase (3-5 d post-injury) and enhanced the expression of myoblast-differentiation markers; M2 were confirmed to produce HGF as monitored by in vivo/ex vivo immunocytochemistry of CD11b/CD206/HGF-positive cells and by HGF in situ hybridization of cardiotoxin- or crush-injured tibialis anterior muscle, respectively. Findings, therefore, encourage the idea that M2 contribute to spatiotemporal up-regulation of extracellular Sema3A concentrations by producing HGF that, in turn, stimulates a burst of Sema3A secretion by myoblasts that are recruited to site of injury. This regulatory axis of “M2 macrophages → satellite cell-derived myoblasts → intramuscular motoneuron terminals” may ensure a coordinated delay in attachment of motoneuron terminals onto regenerating/generating (new) fibers early in muscle regeneration, and thus synchronize the recovery of muscle-fiber integrity after injury.

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (scientific journal)  

Sema3A is a multifunctional molecule involved in several significant processes, but studies have so far neglected its potential impact in muscle biology. Research from Kyushu University in Japan is beginning to unravel its important role and results to date are promising.

Language：English   Publishing type：Research paper (scientific journal)  

Regenerative mechanisms that regulate intramuscular motor innervation are thought to reside in the spatiotemporal expression of axon-guidance molecules. Our previous studies proposed a heretofore unexplored role of resident myogenic stem cell (satellite cell)-derived myoblasts as a key presenter of a secreted neural chemorepellent semaphorin 3A (Sema3A); hepatocyte growth factor (HGF) triggered its expression exclusively at the early-differentiation phase. In order to verify this concept, the present study was designed to clarify a paracrine source of HGF release. In vitro experiments demonstrated that activated anti-inflammatory macrophages (CD206-positive M2) produce HGF and thereby promote myoblast chemoattraction and Sema3A expression. Media from pro-inflammatory macrophage cultures (M1) did not show any significant effect. M2 also enhanced the expression of myoblast-differentiation markers in culture, and infiltrated predominantly at the early-differentiation phase (3-5 days post-injury); M2 were confirmed to produce HGF as monitored by in vivo/ex vivo immunocytochemistry of CD11b/CD206/HGF-positive cells and by HGF in situ hybridization of cardiotoxin- or crush-injured tibialis anterior muscle, respectively. These studies advance our understanding of the stage-specific activation of Sema3A expression signaling. Findings, therefore, encourage the idea that M2 contribute to spatiotemporal up-regulation of extracellular Sema3A concentrations by producing HGF that, in turn, stimulates a burst of Sema3A secretion by myoblasts that are recruited to site of injury. This model may ensure a coordinated delay in re-attachment of motoneuron terminals onto damaged fibers early in muscle regeneration, and thus synchronize the recovery of muscle-fiber integrity and the early resolution of inflammation after injury.

DOI： 10.1016/j.biocel.2014.05.032

Language：English   Publishing type：Research paper (scientific journal)  

Muscle damage induces massive macrophage infiltration of the injury site, in which activated proinflammatory and antiinflammatory phenotypes (currently classified as M1 and M2, respectively) have been documented as distinct functional populations predominant at different times after the conventional acute injury by intramuscular injection of snake venoms (cardiotoxin, notexin) or chemicals (bupivacaine hydrochloride, barium chloride). The present study employed a muscle-crush injury model that may reflect the more physiologic damage and repair processes initiated by contusing a gastrocnemius muscle in lower hind-limb of adult mice with hemostat forceps, and examined the time-course invasion of M1 and M2 macrophages during muscle regeneration by immunocytochemistry of CD197 and CD206 marker proteins. CD197-positive M1 macrophages were observed exclusively at 1-4 days after crush followed by the alternative prevalence of CD206-positive M2 at 7-days of myogenic differentiation time-point characterized by increasing levels of myogenin mRNA expression. Preliminary PCR analysis showed that M2 may produce hepatocyte growth factor (HGF) in culture, providing additional benefit to understanding that M2 populations actively promote regenerative myogenesis (muscle fiber repair) and moto-neuritogenesis (re-attachment of motoneuron terminals onto damaged fibers) through their time-specific infiltration and release of the growth factor at the injury site early in muscle regeneration.

DOI： 10.1111/asj.12105

Language：English   Publishing type：Research paper (international conference proceedings)  

Semaphorin 3A (Sema3A), a class 3 vertebrate-secreted semaphorin originally characterized as a potent neural chemorepellent, is now recognized to play crucial roles in angiogenesis, organogenesis, osteoclastogenesis and immune responses as a multi-functional modulator. Recently, we found that resident myogenic stem cells, satellite cells, up-regulate Sema3A expression and secretion exclusively at the early-myogenic differentiation phase in response to in vivo crush injury and hepatocyte growth factor treatment in the primary cultures (Tatsumi et al., 2009); however, its physiological significance in muscle regeneration is still unknown. Here we show that Sema3A impacts slow-type myosin heavy chain (slow-MyHC) expression in mouse satellite cell cultures. Sema3A-siRNA transfection significantly reduced expression of slow-MyHC as well as the muscle-specific transcription factor myogenin, and the down-stream mediators MEF2 as revealed by qPCR and western blotting analyses. Total MyHC expression level was unchanged, likely due to compensatory up-regulation of fast-MyHC during the 72-hr transfection period. Similar responses (except for fast-MyHC) were also observed in myogenin-knockdown cultures. In addition, reduced myogenin expression induced by immunoneutralization of the receptor neuropilin1 (Npn1) was rescued by co-addition of Sema3A protein. These results therefore indicate that Sema3A may activate a slow-MyHC expression-signaling axis consisting of Npn1, myogenin and MEF2. This model is supported by our comparative observations that satellite cells from soleus muscle (abundant in slow fibers) showed higher expression of Sema3A, myogenin and a co-receptor plexinA2 than those from EDL (Suzuki et al. 2013). Overall, the findings highlight a heretofore unexplored and active role for satellite cell-derived Sema3A as a key modulator of slow fiber generation during muscle regeneration, and advance our understanding of the multi-functional contributions of Sema3A.

Language：English   Publishing type：Research paper (international conference proceedings)  

Skeletal muscle regeneration and work-induced hypertrophy are initiated by mechanical insult or other perturbation and one of the earliest events is triggering the activation (re-entry to cell cycle from G0) of quiescent resident myogenic stem cells, satellite cells. Recent studies of satellite cells in culture and in vivo addressed the possible dual-roles of hepatocyte growth factor (HGF) in the stretch-induced activation and the re-establishing quiescence. In the proposed scenario, the time-coordinated increase in extracellular HGF is a key modulator for the two contrary pathways having low and high thresholds to impact activation and the counterpart quiescence of satellite cells, respectively. Moreover, the role of HGF in muscle repair may not be restricted to myogenesis; we demonstrated that HGF up-regulates expression of secreted axon-guidance molecule semaphorin 3A (Sema3A) in satellite cells at early-differentiation phase in primary cultures and in vivo. The results encourage a possible implication of satellite cells in the spatiotemporal regulation of extracellular Sema3A concentrations, which potentially mediates restoration or remodeling of nerve-muscle connections in muscle regeneration in synchrony with recovery of muscle-fiber integrity and types (fast and slow). Very recently, we found in satellite cell cultures that the Sema3A ligand impacts slow-twitch fiber generation through a muscle-specific transcription factor myogenin-dependent pathway; Sema3A-siRNA transfection significantly reduced expression of slow-type myosin heavy chain (slow-MyHC) as well as myogenin and its co-mediator MEF2. Total MyHC protein expression level was likely unchanged, due to compensatory up-regulation of fast-MyHC and similar responses (except for fast-MyHC) were also observed in myogenin-knockdown cultures. Overall our results highlight the “programmed mechano-biology dynamics” that successful muscle regeneration, comprised of satellite cell-driving myogenesis, intramuscular moto-neuritogenesis and fiber-type regulation (survival), may be a programmed sequence of events that respond to a mechanical perturbation in a synchronous, HGF-dependent and time-coordinated manner.

Language：English   Publishing type：Research paper (scientific journal)  

Regenerative mechanisms that regulate intramuscular motor innervation including configuration of the neuromuscular connections are thought to reside in the spatiotemporal expression of axon-guidance molecules. Our previous studies proposed a heretofore unexplored role of satellite cells as a key source of a secreted neural chemorepellent semaphorin 3A (Sema3A) expression. In order to verify this concept, there is still a critical need to provide direct evidence to show the up-regulation of Sema3A protein in satellite cells in vivo upon muscle injury. The present study employed a Sema3A/MyoD double-immunohistochemical staining for cryo-sections prepared from cardiotoxin (CTX)-injected gastrocnemius muscle of adult mouse lower hind-limb. Results clearly demonstrated that Sema3A expression was up-regulated in MyoD-positive satellite cells at 4-12 days post-injury period, the time that corresponds to the cell differentiation phase characterized by increasing myogenin mRNA expression. This direct proof encourages a possible implication of satellite cells in the spatiotemporal regulation of extracellular Sema3A concentrations, which potentially ensures coordinating a delay in neurite sprouting and re-attachment of motoneuron terminals onto damaged muscle fibers early in muscle regeneration in synchrony with recovery of muscle-fiber integrity.

DOI： 10.1111/asj.12104

Language：English   Publishing type：Research paper (scientific journal)  

Resident myogenic stem cells, satellite cells, up-regulate a secreted multi-functional modulator, semaphorin 3A (Sema3A), exclusively at the early-differentiation phase in response to muscle-crush injury and treatment with hepatocyte growth factor (HGF) or basic fibroblast growth factor (FGF2). Here, we add evidence that the Sema3A expression and secretion induced by the growth factors is significantly higher in primary cultures from adult rat soleus than from the fast-twitch extensor digitorum longus (EDL) muscle. The higher Sema3A response, revealed by quantitative PCR and western blotting of cell lysates and conditioned media, may account for the higher myogenin expression of soleus muscle satellite cells early in differentiation since addition of recombinant Sema3A stimulates myogenin expression in cultures. These experiments also showed that mRNA expression of plexin A2, which together with neuropilins, constitutes Sema3A composite-receptors, was higher in satellite cells from soleus than EDL with no difference in plexin A1 and A3 and neuropilin-1 and 2 levels. These comparative studies, therefore, highlight a possible Sema3A-plexin A2-myogenin signaling axis that may ensure promoting early differentiation by soleus muscle satellite cells.

Language：English   Publishing type：Research paper (scientific journal)  

Successful regeneration and remodeling of neuromuscular junctions are critical for restoring functional capacities and properties of skeletal muscle after damage, and axon-guidance molecules may be involved in the signaling that regulates such restoration. Recently, we found that early-differentiated satellite cells up-regulate a secreted neural chemorepellent Sema3A upon in vivo muscle-crush injury. The study also revealed that Sema3A expression is up-regulated in primary satellite-cell cultures in response to hepatocyte growth factor (HGF) and basic fibroblast growth factor (FGF2) and prevented by transforming growth factor (TGF)-β2, 3 (Tatsumi et al. 2009. Am J Physiol Cell Physiol; Do et al. 2011. Am J Physiol Cell Physiol). In order to verify the physiological significance of this regulation in vitro, the present study was designed to estimate the time-course of extracellular HGF, FGF2 and TGF-β3 concentrations after crush-injury of gastrocnemius muscle in the rat lower hind-limb, using a combination of a non-homogenization/non-spin extraction of extracellular wound fluids and ECL-western blotting analyses. Results clearly demonstrated that active HGF and FGF2 are prevalent in 2-8 days post-crush, whereas active TGF-β3 increases after 12 days, providing a better understanding of the time-coordinated levels of HGF, FGF2, and TGF-β3 that drive regulation of Sema3A expression during regenerative intramuscular moto-neuritogenesis.

Language：English   Publishing type：Research paper (international conference proceedings)  

When skeletal muscle is stretched or injured, satellite cells, resident myogenic stem cells positioned beneath the basal lamina of mature muscle fibers, are activated to enter the cell cycle. This signaling pathway is a cascade of events including calcium-calmodulin formation, nitric oxide (NO) radical production by NO synthase, matrix metalloproteinase activation, release of hepatocyte growth factor (HGF) from the extracellular matrix, and presentation of HGF to the receptor c-met, as demonstrated by assays of primary cultures and in vivo experiments. Here, we add evidence that two ion channels, the mechano-sensitive cation channel (MS-channel) and the long-lasting-type voltage-gated calcium-ion channel (L-VGC-channel), mediate the influx of extracellular calcium ions in response to cyclic stretch in satellite-cell cultures. When applied to 1-hr stretch cultures with individual inhibitors for MS- and L-VGC-channels (GsMTx-4 and nifedipine, respectively) or with a less specific inhibitor for MS-channels (gadolinium chloride, Gd), satellite cell activation and upstream HGF release were abolished, as revealed by bromodeoxyuridine-incorporation assays and western blotting of conditioned media, respectively. The inhibition was dose-dependent with a maximum at 0.1 μM (GsMTx-4), 10 μM (nifedipine) or 100 μM (Gd) and cancelled by addition of HGF to the culture media; a potent inhibitor for transient-type VGC-channels (NNC55-0396, 100 μM) did not show any significant inhibitory effect. The stretch response was also abolished when calcium-chelator EGTA (1.8 mM) was added to the medium, indicating the significance of extracellular free calcium ions in our present activation model. Finally, cation/calcium channel dependencies were further documented by calcium-imaging analyses on stretched cells; results clearly demonstrated that calcium ion influx was abolished by GsMTx-4, nifedipine and EGTA. Therefore, these results provide an additional insight that calcium ions may flow in through L-VGC-channels by possible coupling with adjacent MS-channel gating that promotes the local depolarization of cell membranes to impact the satellite cell activation cascade.

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Skeletal muscle fibers are classified as type I (red/oxidative/slow) and type II (white/glycolytic/fast) based on color, metabolism and contractile properties. Type I fibers are especially mitochondria-rich and use oxidative metabolism for energy production. Thus, an increase of type I fibers can counteract obesity and reduce fatigue. In a recent study, the nuclear receptor peroxisome proliferator-activated receptor (PPAR) δ attracted attention as a factor regulating muscle fiber type. Over-expression of activated PPARδ caused a shift to slow-type fibers (Wang et al. 2004, PLoS Biol., 2: 1532-1539) and polyunsaturated fatty acid (PUFA) has the ligand activity of PPARδ (Forman et al. 1996, Ann. N.Y.Acad.Sci., 804: 266-275). Recently, we found in rat skeletal muscle that fiber type distribution was slower in vivo after feeding with fish oil. To elucidate this phenomenon, we hypothesized that the change to slow muscle with fish oil results from fish oil PUFA activating the receptor activity of PPARδ. Here, we tested the hypothesis using a rat muscle fiber culture assay. Since muscle fiber-type transformation generally occurs in mature fibers, this culture model has the advantage that fibers can express mature MyHC isoforms while differentiated cell lines such as C2C12 and L6 cannot. Rat fiber cultures were established according to the mouse protocol (Wozniak and Anderson 2005, Biochem.Cell Biol., 83: 674-676) and over 90% muscle fibers were alive until 7 days of culture. When the PPARδ−specific agonist (GW501516) was added to fibers cultured for 7 days, transcript expression of MyHC1and 2A was up-regulated at day 1, lipoprotein lipase message was up-regulated at day 3, and pyruvate dehydrogenase kinase (PDK) 4 and uncoupling protein 3 were up-regulated at day 7. Using luciferase reporter assays, PPARδ ligand activity was measured for several kinds of fatty acid. Results showed that, eicosapentaenoic acid (EPA), abundant in fish oil, had higher ligand activity to PPARδ compared with other fatty acids. When EPA was added to fiber cultures for 24 hours, PDK4 mRNA was up-regulated. In addition, when both EPA and PPARδ-specific antagonist (GSK0660) were added to fiber cultures, the up-regulation of PDK4 mRNA by addition of EPA was reseted to the control level. In conclusion, EPA up-regulates a protein characteristic of slow-type muscle via PPARδ activation and may transform muscle fiber type into slow type.

Language：English   Publishing type：Research paper (international conference proceedings)  

Semaphorin 3A (Sema3A, also referred to as SemaIII, SemD and collapsin), a class 3 vertebrate-secreted semaphorin, is a potent axon-guidance cue for sensory, sympathetic and motor axons. Recently, we found that satellite cells up- or down-regulate Sema3A in time-dependent responses to in vivo muscle crush-injury and in vitro treatment with recombinant HGF, FGF2 or TGF-βs. Such responses imply that satellite cells are involved in regenerative motoneuritogenesis, including sprouting and re-attachment of motoneuron terminals onto damaged muscle fibers. In order to explore the mechanism of HGF/FGF2-induced Sema3A up-regulation, the present study was designed to investigate possible membrane receptors that are present on satellite cells and could be involved in that signaling pathway. First, we tested whether c-met and FGFR1, high-affinity receptors of HGF and FGF2 respectively, are responsible for Sema3A up-regulation. Treatment with anti-c-met and anti-FGFR1 neutralizing antibodies did not diminish Sema3A up-regulation, indicating that c-met and FGFR1 may not mediate the response. In addition to such high-affinity receptors, HGF and FGF2 also bind with lower affinity to glycosaminoglycan (GAG) chains of proteoglycans - an important component of extracellular matrix- for a variety of biological functions. We therefore hypothesized that the association between HGF/FGF2 and GAG chains might mediate the Sema3A up-regulation. To test the hypothesis, satellite cell cultures were pretreated with GAG-degrading enzymes before the addition of HGF or FGF2, and the level of Sema3A expression was quantified by real-time qPCR. Results showed that treatment with heparitinase for partial removal of heparan sulfate chains significantly decreased induction of Sema3A up-regulation by HGF, but not FGF2. Similarly, treatment with chondroitinase ABC for partial removal of chondroitin sulfate chains significantly diminished the Sema3A up-regulation induced by FGF2, but not HGF. These results suggest that HGF and FGF2 bind to receptors carrying heparan and/or chondroitin sulfate chains; syndecans or other transmembrane-type proteoglycans appear to be plausible receptor candidates for signaling via growth factors to up-regulate Sema3A in satellite cells in culture.

Language：English   Publishing type：Research paper (international conference proceedings)  

Semaphorin 3A (Sema3A), a class 3 vertebrate-secreted semaphorin, is a potent axon-guidance molecule for sensory, sympathetic and motor neurons. Recently, we found that resident myogenic stem cells, satellite cells, up-regulate Sema3A expression and secretion exclusively at the early-myogenic differentiation phase in response to in vivo crush injury and HGF/FGF2 treatments in the primary cultures, suggesting possible implication of satellite cells in regenerative motoneuritogenesis including sprouting and attachment of motoneuron terminals onto damaged muscle fibers in synchrony with recovery of muscle-fiber structures (Tatsumi et al., Am. J. Physiol. Cell Physiol. 2009; Do et al., Am. J. Physiol. Cell Physiol. 2011). Here, we show that Sema3A also mediates post-natal myogenesis by stimulating the early differentiation of satellite cells. When recombinant Sema3A (R&D Systems) was added to satellite cell cultures for 24 hr from 48-hr post-plating, myogenin message (an early differentiation marker) was up-regulated in a dose-dependent manner with a maximum at 10 ng/ml. Sema3A-specific knock-down by RNAi technique (about 60-75% reduction efficiency) remarkably down-regulated myogenin expression at message and protein levels at the early-differentiation stage, however showed no significant effect on MyoD expression at the same phase and myosin heavy chain expression and myotube formation at the later stage. Immunofluorescence analysis revealed the presence of Sema3A membrane-receptor neuropilin1 (Npn1) at 48-hr post-plating, which is the early-differentiation time-point which siRNA was transfected to cells; immunoneutralization of Npn1 activity also reduced the myogenin expression, which can be rescued competitively by co-addition of Sema3A protein, to a level equivalent to control cultures without anti-Npn1 antibody and Sema3A. These results indicate that satellite cell-secreted Sema3A may bind to the receptor Npn1 to generate myogenin expression signaling that stimulates early differentiation of satellite cells in autocrine and/or paracrine fashions. This topic may be supported potentially by our comparative observations that rat soleus muscle satellite cells showed higher expression activities of Sema3A, myogenin, and plexinA2 (a signaling co-receptor protein for Sema3A) than EDL muscle cells at the early-differentiation stage. Overall, the data highlight again a heretofore unexplored and active role for Sema3A as a key regulator of the early myogenic differentiation of satellite cells during muscle regeneration, therefore providing a better understanding of multi-functional contributions of Sema3A.

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

筋肥大・再生において筋幹細胞（衛星細胞）が合成・分泌する神経軸索ガイダンス因子Sema3Aによって運動神経末端の再接着（神経支配の回復）が制御されていることをはじめて見出した他、このSema3Aの発現がHGF/FGF2/TGF-beta2,3によって時系列的に調節されていることを示した。

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (international conference proceedings)  

In undamaged postnatal muscle fibers with normal contraction and relaxation activities, quiescent satellite cells of resident
myogenic stem cells are interposed between the overlying external lamina and the sarcolemma of a subjacent mature
muscle fiber. When muscle is injured, exercised, overused or mechanically stretched, these cells are activated to enter the
cell proliferation cycle, divide, differentiate, and fuse with the adjacent muscle fiber, and are responsible for regeneration
and work-induced hypertrophy of muscle fibers. Therefore, a mechanism must exist to translate mechanical changes in
muscle tissue into chemical signals that can activate satellite cells. Recent studies of satellite cells or single muscle fibers in
culture and in vivo demonstrated the essential role of hepatocyte growth factor (HGF) and nitric oxide (NO) radical in the
activation pathway. These experiments have also reported that mechanically stretching satellite cells or living skeletal
muscles triggers the activation by rapid release of HGF from its extracellular tethering and the subsequent presentation to
the receptor c-met. HGF release has been shown to rely on calcium-calmodulin formation and NO radical production in
satellite cells and/or muscle fibers in response to the mechanical perturbation, and depend on the subsequent
up-regulation of matrix metalloproteinase (MMP) activity. These results indicate that the activation mechanism is a cascade
of events including calcium ion influx, calcium-calmodulin formation, NO synthase activation, NO radical production, MMP
activation, HGF release and binding to c-met. Better understanding of ‘mechano-biology’ on the satellite cell activation is
essential for designing procedures that could enhance muscle growth and repair activities in meat-animal agriculture and
also in neuromuscular disease and aging in humans.

Language：English   Publishing type：Research paper (international conference proceedings)  

筋肥大・再生の過程で、筋幹細胞（衛星細胞）が肝細胞増殖因子HGF依存的に神経軸索ガイダンス因子Sema3Aを合成・分泌することを見出し、衛星細胞が運動神経末端の再接着制御に能動的に関与している可能性を提起した。このアイデアが評価され、掲載雑誌のEditorial Focusに選定された。

Language：English   Publishing type：Research paper (international conference proceedings)  

筋肥大・再生の過程で、筋幹細胞（衛星細胞）が肝細胞増殖因子HGF依存的に神経軸索ガイダンス因子Sema3Aを合成・分泌することを見出し、衛星細胞が運動神経末端の再接着制御に能動的に関与している可能性を提起した。このアイデアが評価され、掲載雑誌のEditorial Focusに選定された。

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Sato, Y., Probst, H. C., Tatsumi, R., Ikeuchi, Y., Neuberger, M. S., and Rada, C.
Deficiency in APOBEC2 Leads to a Shift in Muscle Fiber Type, Diminished Body Mass and Myopathy.
Journal of Biological Chemistry 285, 7111-7118 (2010).

Language：English   Publishing type：Research paper (scientific journal)  

骨格筋の肥大・再生は筋幹細胞である衛星細胞の増殖活性に依存しており、これは衛星細胞の活性化と休止化のバランスによって制御されている。これまでに、肝細胞増殖因子HGFによる衛星細胞の活性化機構を明らかにしてきたが、これと逆反応の休止化もまたHGFによって誘導されることを見出した。物理刺激をトリガーにして、HGF濃度依存的に衛星細胞が活性化・増殖した後に自立的に休止化するという、独創的な時系列進行モデルを提起した。

Language：English   Publishing type：Research paper (scientific journal)  

筋幹細胞である衛星細胞が物理刺激を引き金として活性化・増殖し筋肥大・再生に寄与する分子メカニズムを解明した一連の研究を、Animal Science Jouranlの招待総説論文として発表した。

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

筋幹細胞である衛星細胞が物理刺激を引き金として活性化・増殖し筋肥大・再生に寄与する分子メカニズムを解明した一連の研究を、招待総説論文に紹介した。本論文は2008年に掲載され、その後の論文引用回数などが評価され２０１１年度の優秀論文賞を受賞した。

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1002/mus.20114

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1002/mus.20102

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1091/mbc.E02-01-0062

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Muscle fiber type composition (% slow-twitch and % fast-twitch fibers) is associated with metabolism,
with increased slow-twitch fibers alleviating metabolic disorders. Previously, we reported that dietary
fish oil intake induced a muscle fiber-type transition in a slower direction in rats. The aim of this study
was to determine the functionality of eicosapentaenoic acid (EPA), a unique fatty acid in fish oil, to skeletal
muscle fiber type and metabolism in rats. Here, we showed that dietary EPA promotes whole-body oxidative
metabolism and improves muscle function by increasing proportion of slow-twitch type 1 fibers in
rats. Transcriptomic and metabolomic analyses revealed that EPA supplementation activated the peroxisome
proliferator-activated receptor d (PPARd) and AMP-activated protein kinase (AMPK) pathways in
L6 myotube cultures, which potentially increasing slow-twitch fiber share. This highlights the role of
EPA as an exercise-mimetic dietary component that improves metabolism and muscle function, with potential
benefits for health and athletic performance.

DOI： 10.1016/j.isci.2024.109816

Language：English   Publishing type：Research paper (scientific journal)  

Skeletal muscle is one of the largest metabolic tissues in mammals and is composed of four different
types of muscle fibers (types 1, 2A, 2X, and 2B); however, type 2B is absent in humans. Given that
slow-twitch fibers are superior to fast-twitch fibers in terms of oxidative metabolism and are rich in
mitochondria, shift of muscle fiber types in direction towards slower fiber types improves metabolic
disorders and endurance capacity. We previously had reported that oleic acid supplementation
increases type 1 fiber formation in C2C12 myotubes; however, its function still remains unclear. This
study aimed to determine the effect of oleic acid on the muscle fiber types and endurance capacity.
An in vivo mouse model was used, and mice were fed a 10% oleic acid diet for 4 weeks. Two different
skeletal muscles, slow soleus muscle with the predominance of slow-twitch fibers and fast extensor
digitorum longus (EDL) muscle with the predominance of fast-twitch fibers, were used. We found
that dietary oleic acid intake improved running endurance and altered fiber type composition of
muscles, the proportion of type 1 and 2X fibers increased in the soleus muscle and type 2X increased
in the EDL muscle. The fiber type shift in the EDL muscle was accompanied by an increased muscle
TAG content. In addition, blood triacylglycerol (TAG) and non-esterified fatty acid levels decreased
during exercise. These changes suggested that lipid utilization as an energy substrate was enhanced
by oleic acid. Increased proliferator-activated receptor γ coactivator-1β protein levels were observed
in the EDL muscle, which potentially enhanced the fiber type transitions towards type 2X and
muscle TAG content. In conclusion, dietary oleic acid intake improved running endurance with the
changes of muscle fiber type shares in mice. This study elucidated a novel functionality of oleic acid in
skeletal muscle fiber types. Further studies are required to elucidate the underlying mechanisms. Our
findings have the potential to contribute to the field of health and sports science through nutritional
approaches, such as the development of supplements aimed at improving muscle function.

DOI： 10.1038/s41598-023-50464-y

Other Link： https://doi.org/10.1038/s41598-023-50464-y

Language：English   Publishing type：Research paper (scientific journal)  

Satellite cells are indispensable for skeletal muscle regeneration and hypertrophy by forming nascent myofibers (myotubes). They synthesize multi-potent modulator netrins (secreted subtypes: netrin-1, -3, and -4), originally found as classical neural axon guidance molecules. While netrin-1 and -3 have key roles in myogenic differentiation, the physiological significance of netrin-4 is still unclear. This study examined whether netrin-4 regulates myofiber type commitment and myotube formation. Initially, the expression profiles indicated that satellite cells isolated from the extensor digitorum longus muscle (EDL muscle: fast-twitch myofiber-abundant) expressed slightly more netrin-4 than the soleus muscle (slow-type abundant) cells. As netrin-4 knockdown inhibited both slow- and fast-type myotube formation, netrin-4 may not directly regulate myofiber type commitment. However, netrin-4 knockdown in satellite cell-derived myoblasts reduced the myotube fusion index, while exogenous netrin-4 promoted myotube formation, even though netrin-4 expression level was maximum during the initiation stage of myogenic differentiation. Furthermore, netrin-4 knockdown also inhibited MyoD (a master transcriptional factor of myogenesis) and Myomixer (a myoblast fusogenic molecule) expression. These data suggest that satellite cells synthesize netrin-4 during myogenic differentiation initiation to promote their own fusion, stimulating the MyoD–Myomixer signaling axis.

DOI： 10.1016/j.yexcr.2023.113698

Language：English   Publishing type：Research paper (scientific journal)  

Skeletal muscle atrophy occurs rapidly as a result of inactivity. Although there are many reports on changes in gene expression during the early phase of muscle atrophy, the patterns of up-and downregulated gene expression after long-term and equilibrated muscle atrophy are poorly understood. In this study, we comprehensively examined the changes in gene expression in long-term denervated mouse muscles using RNA-Seq. The murine right sciatic nerve was denervated, and the mice were housed for five weeks. The cross-sectional areas of the hind limb muscles were measured using an X-ray CT system 35 days after denervation. After 28 d of denervation, the cross-sectional area of the muscle decreased to approximately 65% of that of the intact left muscle and reached a plateau. Gene expression in the soleus and extensor digitorum longus (EDL) muscles on the 36th day was analyzed using RNA-Seq and validated using RT-qPCR. RNA-Seq analysis revealed that three genes—Adora1, E230016M11Rik, and Gm10718—were upregulated and one gene—Gm20515—was downregulated in the soleus muscle; additionally, four genes—Adora1, E230016M11Rik, Pigh, and Gm15557—were upregulated and one gene—Fzd7—was downregulated in the EDL muscle (FDR < 0.05). Among these genes, E230016M11Rik, one of the long non-coding RNAs, was significantly upregulated in both the muscles. These findings indicate that E230016M11Rik could be a candidate gene for the maintenance of atrophied skeletal muscle size and an atrophic state.

DOI： 10.3390/life13051111

Other Link： https://doi.org/10.3390/life13051111

Language：English   Publisher：American Journal of Pathology  

α-Klotho is a longevity-related protein. Its deficiency shortens lifespan with prominent senescent phenotypes, including muscle atrophy and weakness in mice. α-Klotho has two forms: membrane α-Klotho and circulating α-Klotho (c-α-Klotho). Loss of membrane α-Klotho impairs a phosphaturic effect, thereby accelerating phosphate-induced aging. However, the mechanisms of senescence on c-α-Klotho loss remain largely unknown. Herein, with the aging of wild-type mice, c-α-Klotho declined, whereas Smad2, an intracellular transforming growth factor (TGF)-β effector, became activated in skeletal muscle. Moreover, c-α-Klotho suppressed muscle-wasting TGF-β molecules, including myostatin, growth and differentiation factor 11, activin, and TGF-β1, through binding to ligands as well as type I and type II serine/threonine kinase receptors. Indeed, c-α-Klotho reversed impaired in vitro myogenesis caused by these TGF-βs. Oral administration of Ki26894, a small-molecule inhibitor of type I receptors for these TGF-βs, restored muscle atrophy and weakness in α-Klotho (−/−) mice and in elderly wild-type mice by suppression of activated Smad2 and up-regulated Cdkn1a (p21) transcript, a target of phosphorylated Smad2. Ki26894 also induced the slow to fast myofiber switch. These findings show c-α-Klotho's potential as a circulating inhibitor counteracting TGF-β–induced sarcopenia. These data highlight the potential of a novel therapy involving TGF-β blockade to prevent sarcopenia.

DOI： 10.1016/j.ajpath.2023.01.009

Web of Science

Scopus

PubMed

Language：English   Publishing type：Research paper (scientific journal)  

DOI： doi.org/10.1016/j.ajpath.2023.01.009

Language：English   Publishing type：Research paper (scientific journal)  

DOI： doi.org/10.2141/jpsa.0220003

Language：English   Publishing type：Research paper (bulletin of university, research institution)  

DOI： doi.org/10.5109/4772335

Other Link： https://doi.org/10.5109/4772335

Language：English   Publisher：Japan Poultry Science Association  

<p>Smooth muscle cells are widely distributed in the digestive organs of chickens. They exist as single cells, but adhere to each other to function synchronously. In this study, the expression of the gap junction protein connexin 43 (Cx43) in chicken gizzards was investigated at embryonic days (E) 10, E15, and E18. Gizzards have an abundance of smooth muscle cells because of their thick muscle layers, which enable easy analysis of the cells. Morphological observations and expression patterns of smooth muscle markers were confirmed. Next, we observed where the markers were localized in the gizzard tissue at E10, E15, and E18. Finally, the expression pattern of Cx43 in primary cultured smooth muscle cells from E15 gizzards was investigated. The analysis revealed the expression and localization of Cx43 and calponin 1 in the smooth muscle layers, and 3D analysis revealed dynamic changes in the localization pattern of Cx43 from E10 to E15. Cultured smooth muscle cells confirmed that Cx43 was expressed in the cell membrane and cytosol. In conclusion, Cx43 expression was identified in chicken gizzards at E10, E15, and E18, which was localized differently during development. The expression was broad at E10, and became restricted at E15 and E18. Primary culture of smooth muscle cells showed that Cx43 was present in the cell membrane and cytosol. This suggests that Cx43 is actively translated into the cytosol at E10, forming a hexamer, and shuttling the cell membrane to function as a gap junction.</p>

DOI： 10.2141/jpsa.0220003

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Scopus

PubMed

CiNii Research

Web of Science

Language：English   Publishing type：Research paper (scientific journal)  

Resident myogenic stem cells (satellite cells) are attracting attention for their novel roles in
myofiber type regulation. In the myogenic differentiation phase, satellite cells from soleus muscle
(slow fiber-abundant) synthesize and secrete higher levels of semaphorin 3A (Sema3A, a multifunctional
modulator) than those derived from extensor digitorum longus (EDL; fast fiber-abundant),
suggesting the role of Sema3A in forming slow-twitch myofibers. However, the regulatory mechanisms
underlying fast-twitch myotube commitment remain unclear. Herein, we focused on netrin
family members (netrin-1, -3, and -4) that compete with Sema3A in neurogenesis and osteogenesis.
We examined whether netrins affect fast-twitch myotube generation by evaluating their expression in
primary satellite cell cultures. Initially, netrins are upregulated during myogenic differentiation. Next,
we compared the expression levels of netrins and their cell membrane receptors between soleus- and
EDL-derived satellite cells; only netrin-1 showed higher expression in EDL-derived satellite cells than
in soleus-derived satellite cells. We also performed netrin-1 knockdown experiments and additional
experiments with recombinant netrin-1 in differentiated satellite cell-derived myoblasts. Netrin-1
knockdown in myoblasts substantially reduced fast-type myosin heavy chain (MyHC) expression;
exogenous netrin-1 upregulated fast-type MyHC in satellite cells. Thus, netrin-1 synthesized in
EDL-derived satellite cells may promote myofiber type commitment of fast muscles.

Language：English   Publishing type：Research paper (scientific journal)  

Although skeletal muscle cells and adipocytes are derived from the same mesoderm, they do not transdifferentiate in vivo and are strictly distinct at the level of gene expression. To elucidate some of the regulatory mechanisms underlying this strict distinction, Pax7, a myogenic factor, was ectopically expressed in 3T3-L1 adipose progenitor cells to perturb their adipocyte differentiation potential. Transcriptome analysis showed that ectopic expression of Pax7 repressed the expression of some adipocyte genes and induced expression of some skeletal muscle cell genes. We next profiled the epigenomic state altered by Pax7 expression using H3K27ac, an activating histone mark, and H3K27me3, a repressive histone mark, as indicators. Our results show that ectopic expression of Pax7 did not result in the formation of H3K27ac at loci of skeletal muscle-related genes, but instead resulted in the formation of H3K27me3 at adipocyte-related gene loci. These findings suggest that the primary function of ectopic Pax7 expression is the formation of H3K27me3, and muscle gene expression results from secondary regulation.

DOI： doi.org/10.1093/jb/mvab030

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1017/S1751731120000464

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s00394-020-02205-4

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.3390/metabo10010010

Other Link： https://www.mdpi.com/2218-1989/10/1/10

Language：English   Publishing type：Research paper (scientific journal)  

Free amino acids are important components of tastants and flavor precursors in meat. To clarify the correlation between muscle fiber type and free amino acids, we determined the concentrations of various free amino acids and dipeptides in samples of different muscle tissues (n = 21), collected from 26-month-old Japanese Black steers (n = 3) at 2 days postmortem. The proportions of the myosin heavy chain (MyHC), slow (MyHC1) and fast (MyHC2) isoforms were determined by sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS–PAGE). The contents of free amino acids and dipeptides were measured by high performance liquid chromatography (HPLC). The MyHC isoform composition varied among the tissue samples. The MyHC1 proportion ranged from 6.9% ± 3.9% to 83.3% ± 16.7%. We confirmed that there was a strong positive correlation between MyHC1 composition and total free amino acid concentrations, including those for two dipeptides. Among the 31 measured free amino acids and dipeptides, 11 showed significant positive correlations and five showed significant negative correlations with MyHC1 composition. These results suggest that a high MyHC1 content induces high free amino acid contents in bovine muscles possibly because of greater oxidative metabolism. This high level of free amino acids could contribute to the intense flavor of meat that is rich in slow-twitch fibers.

DOI： 10.1111/asj.13185

Language：English   Publishing type：Research paper (scientific journal)  

Skeletal muscle fiber is largely classified into two types: type 1 (slow-twitch) and type 2 (fast-twitch) fibers. Meat quality and composition of fiber types are thought to be closely related. Previous research showed that overexpression of constitutively active peroxisome proliferator-activated receptor (PPAR)δ, a nuclear receptor present in skeletal muscle, increased type 1 fibers in mice. In this study, we found that hexane extracts of Yamabushitake mushroom (Hericium erinaceus) showed PPARδ agonistic activity in vitro. Eight-week-old C57BL/6J mice were fed a diet supplemented with 5% (w/w) freeze-dried Yamabushitake mushroom for 24 hr. After the treatment period, the extensor digitorum longus (EDL) muscles were excised. The Yamabushitake-supplemented diet up-regulated the PPARδ target genes Pdk4 and Ucp3 in mouse skeletal muscles in vivo. Furthermore, feeding the Yamabushitake-supplemented diet to mice for 8 weeks resulted in a significant increase in muscle endurance. These results indicate that Yamabushitake mushroom contains PPARδ agonistic ligands and that dietary intake of Yamabushitake mushroom could activate PPARδ in skeletal muscle of mice. Unexpectedly, we observed no significant alterations in composition of muscle fiber types between the mice fed control and Yamabushitake-supplemented diets.

DOI： 10.1111/asj.13199

Language：English   Publishing type：Research paper (scientific journal)  

Dietary apple polyphenols (AP) have been shown to exhibit beneficial effects on muscle endurance. Fast-to-slow change in the composition of myosin heavy chains was known as one of the molecular mechanisms. Here, we examined the effects of dietary AP on the capillaries and mitochondria in the rat skeletal muscle to elucidate the mechanisms underlying muscular endurance enhancement. Twenty-four Wistar male rats were divided into three groups, namely, the control group, 0.5% AP group, and 5% AP group (n = 8 in each group). After a feeding period of 4 weeks, rats were dissected, gastrocnemius muscles were removed, and the density of capillaries and levels of mitochondrial proteins were analyzed. Capillary density of the gastrocnemius increased to 17.8% in rats fed with 5% AP as compared to the control rats. No significant change was observed in the mitochondrial content and dynamics (fusion/fission) of regulatory proteins. To investigate the mechanisms underlying the increase in the capillary density, positive (vascular endothelial cell growth factor, VEGF) and negative (thrombosponsin-1, TSP-1) factors of angiogenesis were analyzed. TSP-1 expression significantly decreased in rats fed with 0.5% AP and 5% AP by approximately 25% and 40%, respectively, as compared with the control rats. There were no significant differences in VEGF expression. Thus, dietary AP may increase the muscle capillary density by decreasing TSP-1 expression. We concluded that the increase in the capillary density and the fast-to-slow change in myosin heavy chains by AP feeding are the main causes for muscle endurance enhancement in Wistar rats.

DOI： 10.14814/phy2.13866

Language：English   Publishing type：Research paper (scientific journal)  

Myogenesis is precisely proceeded by myogenic regulatory factors. Myogenic stem cells are activated, proliferated and fused into a multinuclear myofiber. Pax7, paired box 7, one of the earliest markers during myogenesis. It has been reported that Pax7 regulates the muscle marker genes, Myf5 and MyoD toward differentiation. The possible roles of Pax7 in myogenic cells have been well researched. However, it has not yet been clarified if Pax7 itself is able to induce myogenic fate in nonmyogenic lineage cells. In this study, we performed experiments using stably expressed Pax7 in 3T3-L1 preadipocytes to elucidate if Pax7 inhibits adipogenesis. We found that Pax7 represses adipogenic markers and prevents differentiation. These cells showed decreased expression of PDGFRα, PPARγ and Fabp4 and inhibited forming lipid droplets.

DOI： 10.1111/asj.13050

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1096/fj.201700493R

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (scientific journal)  

Skeletal muscle is the main tissue of lipid metabolism and accordingly is critical for homeostasis and energy production; however, the determinants of lipid accumulation in skeletal muscle are unknown. Here, we examined whether the soleus muscle (predominantly slow-twitch fibers) has a higher lipid accumulation capacity than that of the extensor digitorum longus (EDL, predominantly fast-twitch fibers) muscle in mice. Soleus and EDL muscles were harvested from male C57BL/6J mice. The mRNA levels of genes involved in fatty acid import and triglyceride synthesis and accumulation were examined in soleus and EDL muscles. The intramyocellular lipid (IMCL) droplets of muscle cross sections and isolated single fibers were visualized by staining with BODIPY493/503, and fiber types were determined by immunofluorescent detection of myosin heavy chain (MyHC) isoforms. We detected higher mRNA expression of genes related to lipid accumulation in the soleus than the EDL. We also observed a marked increase of IMCL in single fibers from the soleus, but not the EDL, after treatment with a high-fat diet plus denervation. Interestingly, greater accumulation of IMCL droplets was observed in type 2A and 2X fibers (MyHC2A- and MyHC2X-positive fibers) than type 1 fibers (MyHC1-positive fibers) in soleus muscles. These results suggest that the soleus contains more IMCL owing to the higher population of type 2A fibers, and the difference in lipid accumulation between the soleus and EDL could depend on fiber type composition.

DOI： 10.1007/s10974-017-9468-6

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1371/journal.pone.0166080

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1002/2211-5463.12050

Language：English   Publishing type：Research paper (scientific journal)  

Since the discovery of leptin secreted from adipocytes, specialized tissues and cells secreted the several peptides (or cytokines) that are characterized to negatively and positively regulate the metabolic process. Different types of adipokines, hepatokines, and myokines, which act as cytokines, are secreted from adipose, liver, and muscle tissue, respectively, and have been identified and examined for their physiological roles in humans and disease in animal models. Recently, various studies of these cytokines have been conducted in ruminants, including dairy cattle, beef cattle, sheep, and goat. Interestingly, a few cytokines from these tissues play an important role in the post-parturition, lactation, and fattening (marbling) periods in ruminants. Thus, understanding these hormones is important for improving nutritional management in dairy cows and beef cattle. However, to our knowledge, there have been no reviews of the characteristics of these cytokines in beef and dairy products in ruminants. In particular, lipid and glucose metabolism in adipose tissue, liver tissue, and muscle tissue are very important for energy storage, production, and synthesis, which are regulated by these cytokines in ruminant production. In this review, we summarize the physiological roles of adipokines, hepatokines, and myokines in ruminants. This discussion provides a foundation for animal production in ruminants.

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.dib.2015.04.016

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.ab.2015.03.034

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1111/asj.12257

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1111/asj.12143.

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1371/journal.pone.0080152

Language：English   Publishing type：Research paper (scientific journal)  

The primary aim of this study was to examine the effects of 48-h food deprivation on rat skeletal muscle fiber type, according to myosin heavy-chain (MyHC) isoform composition and some metabolism-related factors in both slow-type dominant and fast-type dominant muscle tissues. Male Wistar rats (7 wk old) were treated with 48-h food deprivation or ad libitum feeding as control. After the treatment, the soleus muscle (slow-type dominant) and the extensor digitorum longus (EDL, fast-type dominant) were excised. We found that 48-h food deprivation did not affect MyHC composition in either the soleus or EDL, compared with fed rats by electrophoretic separation of MyHC isoforms. However, 48-h food deprivation significantly increased the mRNA expression of fast-type MyHC2B in the EDL muscle. Moreover, food deprivation increased fatty acid metabolism, as shown by elevated levels of related serum energy substrates and mRNA expression of mitochondrial uncoupling protein (UCP) 3 and lipoprotein lipase (LPL) in both the soleus and EDL. UCP3 and LPL are generally expressed at higher levels in slow-type fibers. Furthermore, we found that food deprivation significantly decreased the protein amounts of PGC1α and phosphorylated FOXO1, which are known as skeletal muscle fiber type regulators. In conclusion, 48-h food deprivation increased mRNA expression of fast-type MyHC isoform and oxidative metabolism-related factors in EDL, whereas MyHC composition at the protein level did not change in either the soleus or EDL.

DOI： org/10.3177/jnsv.59.289

Language：English   Publishing type：Research paper (scientific journal)  

Dietary fat plays an important role in higher brain functions. We aimed to assess the short and long term intake of three different types of dietary fat (soybean oil, lard, and fish oil) on anxiety-like and depression-like behavior in mice. For the short term intake assessment, a behavioral test battery for anxiety and depression was carried out for a 3-day feeding period. For the long term intake assessment, a behavioral test battery began after the 4-week feeding period. During the short term intake, the time spent in the open arms of the elevated plus-maze was the longest in the fish oil fed group, followed by the soybean oil and lard-fed groups. The elevated plus-maze is a common animal model to assess anxiety, in which an increased time spent in the open arms indicates an anxiolytic effect. The difference between the fish oil-fed group and lard-fed group was statistically significant (p < 0.01), but there was no significant difference between the soybean oil-fed group and the other two groups. Similar results were observed after a 4-week feeding period. On the other hand, there was no significant difference among the three groups in behavior tests to evaluate depression. Thus, the dietary fat types appeared to influence anxiety but not depression in mice, both in short term (3 days) and long term (4 weeks) feeding.

DOI： 10.1186/2193-1801-2-165

Language：English   Publishing type：Research paper (international conference proceedings)  

APOBEC2 is one a member of AID/APOBEC cytidine deaminase family with putative DNA/RNA editing enzyme. Loss of APOBEC2 leads to a shift in muscle fiber-type, diminished body mass and myofiber with centrally-located nuclei although the molecular mechanisms are unknown. APOBEC2 is localized in z-bands of sarcomere in mouse muscle. Its deficiency did not affect the sarcomere structure although skeletal muscles of APOBEC2 KO (A2-/-) mice had degenerating fibers and rimmed vacuoles (RVs). To test whether the defect of APOBEC2 affected protein degradation system, we investigated the expression level of autophagy-related genes (Map1lc3b, Park2, Pink1 and p62) and ubiquitin ligases (Trim63, Fbxo32). The expression levels of autophagy-related genes were increased although those of ubiquitin ligases were not changed. Immunohistochemical analysis showed accumulated LC3 and p62 in RVs of A2-/- myofiber. Subsequent electron microscopy showed enlarged mitochondria and mitochondria engulfed by autophagosomes in A2-/- muscle. In addition, we found that activated LC3-Ⅱ and poly-ubiquitin were increased and localized to mitochondria of A2-/- muscle. In this study, we demonstrated that APOBEC2 deficiency caused enlarged mitochondria and increased autophagy (especially mitophagy). APOBEC2 may be unknown autophagy-related gene in skeletal muscle.

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1046/j.0014-2956.2001.02664.x

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：Japanese   Book type：Scholarly book

Language：Japanese   Book type：Scholarly book

Language：Japanese   Book type：Scholarly book

Responsible for pages：第67巻 第5号, 559-566   Language：Japanese   Book type：Scholarly book

Responsible for pages：第66巻 第5号, 505-509   Language：Japanese   Book type：Scholarly book

Event date： 2023.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：帯広畜産⼤学、帯広市   Country：Japan  

Event date： 2022.11

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：九州大学椎木講堂   Country：Japan  

Event date： 2022.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン開催（東京農業大学）   Country：Japan  

Event date： 2022.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン開催（東京農業大学）   Country：Japan  

Event date： 2019.8

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：九州大学椎木講堂大会議室、福岡市   Country：Japan  

Event date： 2019.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：日本橋ライフサイエンスビルディング 、東京都   Country：Japan  

骨格筋幹細胞の基礎分子生理学の新奇知見から見えてききた、「筋の疲労耐性の向上（抗疲労性筋線維の形成誘導と脂肪燃焼の促進）」および「加齢性筋萎縮・再生不全（加齢に伴う筋量の低下と結合組織・脂肪組織の過剰な浸潤による筋機能の著しい低下）の主要因の全く新しい理解モデル」について紹介する。いずれも、細胞外因子とその細胞膜受容体が深く関与することから、機能性食品成分による制御および創薬の可能性についても展望する。スポーツ・健康・シルバー科学への貢献が期待される。

Event date： 2018.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：国立精神・神経医療研究センター、東京都小平市   Country：Japan  

Event date： 2018.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：つくば国際会議場、つくば市   Country：Japan  

Event date： 2018.8

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：川崎医科大学、倉敷市   Country：Japan  

Event date： 2018.7

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：Steamboat Springs, CO   Country：Japan  

Event date： 2016.8

Language：English   Presentation type：Oral presentation (general)  

Venue：Kyushu Sangyo University   Country：Japan  

Event date： 2015.8

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：国立研究開発法人国立精神・神経医療研究センター（小平市）   Country：Japan  

Event date： 2015.8

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：国立研究開発法人国立精神・神経医療研究センター（小平市）   Country：Japan  

Event date： 2015.3

Language：English   Presentation type：Oral presentation (general)  

Venue：宇都宮大学、宇都宮市   Country：Japan  

Event date： 2015.3

Language：English   Presentation type：Oral presentation (general)  

Venue：宇都宮大学、宇都宮市   Country：Japan  

Event date： 2014.11

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：パシフィコ横浜、横浜市   Country：Japan  

Event date： 2014.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Universitas Gadjah Mada   Country：Indonesia  

Event date： 2014.9

Language：English   Presentation type：Oral presentation (general)  

Venue：University of Manitoba, Winnipeg   Country：Canada  

Event date： 2014.7

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：Steamboat Springs   Country：United States  

Event date： 2014.7

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：Steamboat Springs   Country：United States  

Event date： 2014.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：日本獣医生命科学大学C棟501講義室、武蔵野市   Country：Japan  

Event date： 2014.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：つくば国際会議場、つくば市   Country：Japan  

Event date： 2014.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：つくば国際会議場、つくば市   Country：Japan  

Event date： 2014.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：つくば国際会議場、つくば市   Country：Japan  

Event date： 2014.3

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：つくば国際会議場（つくば市）   Country：Japan  

要旨:
運動や損傷に伴う骨格筋の肥大・再生は、1)筋肉の主体である筋細胞（筋線維）の肥大・修復および筋線維型(速筋・遅筋型)の決定、2)運動神経末端の筋線維への再接着(神経支配の回復)、3)筋線維を取り巻く毛細血管の再配置、の３つの現象を基盤としている。筋線維の肥大・再生は、筋幹細胞である衛星細胞の活性化・増殖に大きく依存することが知られているが、神経末端の再接着を制御する分子機構は不明である。演者らは、衛星細胞の活性化・休止化機構を調べる過程で、筋再生に伴い分化初期の衛星細胞が肝細胞増殖因子HGFを受容すると神経軸索成長ガイダンス因子Sema3Aを合成・分泌することを見出した。さらには、分化初期に浸潤する抗炎症性マクロファージ(M2)がHGFを大量に分泌し、衛星細胞のSema3A発現を誘導することを明らかにした。これらの知見に基づき本講演では、M2→衛星細胞→神経末端の異種細胞間コミュニケ−ションによって運動神経末端の筋線維への再接着が制御されていることを概説する。また、衛星細胞の活性化と休止化およびSema3Aの合成・分泌がいずれもHGFによって誘導されることから、前述の筋肥大・再生の基盤現象が物理刺激を引き金として時系列進行する自律制御モデルも併せて紹介する。この「筋肥大・再生のメカノバイオロジー」を理解することにより、食肉を効率的に生産する新規技術の開発や、ヒトの筋疾患・加齢・不活動による筋変性退行を抑制する技術開発に資すると期待される。

Abstract:
Successful regeneration and remodeling of neuromuscular connections are critical for restoring functional properties of muscle fibers. While the spatiotemporal regulatory mechanisms coordinating these processes with myogenesis remain unclear, various attractive and repulsive axon-guidance cues may be involved. Recently, we demonstrated that resident myogenic stem-satellite cells up-regulate a secreted neural-chemorepellent Sema3A during the early-differentiation period, in response to hepatocyte growth factor (HGF) elevated in injured muscle. The subsequent experiment showed that a paracrine source of the HGF release may be anti-inflammatory macrophages (M2). These findings therefore highlight a regulatory axis of “M2→satellite cells→motoneuron terminals” as an essential element of paracrine intercellular-communications that ensure the successful regenerative moto-neuritogenesis including the delay in sprouting and attachment of motoneuron terminals onto fibers.

Event date： 2013.10

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：Cemay-la-Ville   Country：France  

Semaphorin 3A (Sema3A), a class 3 vertebrate-secreted semaphorin originally characterized as a potent neural chemorepellent, is now recognized to play crucial roles in angiogenesis, organogenesis, osteoclastogenesis and immune responses as a multi-functional modulator. Recently, we found that resident myogenic stem cells, satellite cells, up-regulate Sema3A expression and secretion exclusively at the early-myogenic differentiation phase in response to in vivo crush injury and hepatocyte growth factor treatment in the primary cultures (Tatsumi et al., 2009); however, its physiological significance in muscle regeneration is still unknown. Here we show that Sema3A impacts slow-type myosin heavy chain (slow-MyHC) expression in mouse satellite cell cultures. Sema3A-siRNA transfection significantly reduced expression of slow-MyHC as well as the muscle-specific transcription factor myogenin, and the down-stream mediators MEF2 as revealed by qPCR and western blotting analyses. Total MyHC expression level was unchanged, likely due to compensatory up-regulation of fast-MyHC during the 72-hr transfection period. Similar responses (except for fast-MyHC) were also observed in myogenin-knockdown cultures. In addition, reduced myogenin expression induced by immunoneutralization of the receptor neuropilin1 (Npn1) was rescued by co-addition of Sema3A protein. These results therefore indicate that Sema3A may activate a slow-MyHC expression-signaling axis consisting of Npn1, myogenin and MEF2. This model is supported by our comparative observations that satellite cells from soleus muscle (abundant in slow fibers) showed higher expression of Sema3A, myogenin and a co-receptor plexinA2 than those from EDL (Suzuki et al. 2013). Overall, the findings highlight a heretofore unexplored and active role for satellite cell-derived Sema3A as a key modulator of slow fiber generation during muscle regeneration, and advance our understanding of the multi-functional contributions of Sema3A.

Event date： 2013.10

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：北海道大学大学院農学研究院 W109室（札幌市）   Country：Japan  

要旨
　運動や損傷に伴う骨格筋の肥大・再生は、1)筋肉の主体である筋細胞（細長い巨大な細胞なので“筋線維”と呼ばれる）の肥大・修復、および筋線維型（速筋・遅筋型）の決定、2)運動神経ネットワーク（神経末端の筋線維への再接着および神経軸索の空間配置）の再構築、3)筋線維を取り巻く毛細血管の再配置、の３つの現象を基盤としている。筋線維の肥大・再生は、衛星細胞（“眠れる筋幹細胞”）の活性化・増殖活性に大きく依存することが知られているが、運動神経ネットワークの再構築（神経支配の回復）を制御する「神経軸索ガイダンス因子の発現機構」は不明である。演者らは、衛星細胞の活性化・休止化機構を調べる過程で、筋損傷に伴い分化初期の衛星細胞が肝細胞増殖因子HGFを受容すると、神経軸索成長ガイダンス因子semaphorin 3A(Sema3A)を合成・分泌することを見出した（Tatsumi et al., Am. J. Physiol. Cell Physiol. 2009; Sato et al., Anim. Sci. J. 2013）。また、TGF-β3の共添加によりHGFによるSema3Aの発現誘導はキャンセルされたことから、発現誘導因子(HGF)と抑制因子(TGF-β3)の時系列的な濃度変化によってSema3A発現が制御されていると考えられた（Do et al., Am. J. Physiol. Cell Physiol. 2011; Do et al., Anim. Sci. J. 2012）。さらには最近、筋再生の分化初期に浸潤してくる代替的活性化マクロファージ（抗炎症性Mφ、M2）がHGFを大量に分泌し、衛星細胞のSema3A発現を誘導することを明らかにした（Sakaguchi et al., PLoS ONE, 投稿中）。これらの知見から、運動神経末端の筋線維への再接着にも衛星細胞と抗炎症性Mφが積極的に関与していると予想され、抗炎症性Mφ→衛星細胞→運動神経末端の制御軸、即ち、筋組織内に存在する異種細胞群の相互連携調節（コミュニケーション）によって筋肥大・再生が巧みに制御されていると考えられた。
　衛星細胞の活性化と休止化 (Yamada et al., Am. J. Physiol. Cell Physiol. 2010)、およびSema3Aの合成・分泌がいずれもHGFによって誘導されることから、前述の筋肥大・再生の基盤現象が物理刺激を引き金として時系列的に自動進行するように巧みに制御されていると推測される。この「筋肥大・再生のプログラムド メカノバイオロジー」を理解することにより、食肉を効率的に生産する新規技術の開発や、ヒトの筋疾患および加齢・不活動による筋変性退行を抑制する技術開発に資すると期待される。

Event date： 2013.9

Language：English   Presentation type：Oral presentation (general)  

Venue：University of Arizona's School of Animal and Comparative Biomedical Sciences, Tucson, AZ   Country：United States  

Skeletal muscle regeneration and work-induced hypertrophy are initiated by mechanical insult or other perturbation and one of the earliest events is triggering the activation (re-entry to cell cycle from G0) of quiescent resident myogenic stem cells, satellite cells. Recent studies of satellite cells in culture and in vivo addressed the possible dual-roles of hepatocyte growth factor (HGF) in the stretch-induced activation and the re-establishing quiescence. In the proposed scenario, the time-coordinated increase in extracellular HGF is a key modulator for the two contrary pathways having low and high thresholds to impact activation and the counterpart quiescence of satellite cells, respectively. Moreover, the role of HGF in muscle repair may not be restricted to myogenesis; we demonstrated that HGF up-regulates expression of secreted axon-guidance molecule semaphorin 3A (Sema3A) in satellite cells at early-differentiation phase in primary cultures and in vivo. The results encourage a possible implication of satellite cells in the spatiotemporal regulation of extracellular Sema3A concentrations, which potentially mediates restoration or remodeling of nerve-muscle connections in muscle regeneration in synchrony with recovery of muscle-fiber integrity and types (fast and slow). Very recently, we found in satellite cell cultures that the Sema3A ligand impacts slow-twitch fiber generation through a muscle-specific transcription factor myogenin-dependent pathway; Sema3A-siRNA transfection significantly reduced expression of slow-type myosin heavy chain (slow-MyHC) as well as myogenin and its co-mediator MEF2. Total MyHC protein expression level was likely unchanged, due to compensatory up-regulation of fast-MyHC and similar responses (except for fast-MyHC) were also observed in myogenin-knockdown cultures. Overall our results highlight the “programmed mechano-biology dynamics” that successful muscle regeneration, comprised of satellite cell-driving myogenesis, intramuscular moto-neuritogenesis and fiber-type regulation (survival), may be a programmed sequence of events that respond to a mechanical perturbation in a synchronous, HGF-dependent and time-coordinated manner.

Event date： 2013.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：新潟大学、新潟市   Country：Japan  

Event date： 2013.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：新潟大学、新潟市   Country：Japan  

Event date： 2013.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：安田女子大学、広島市   Country：Japan  

Event date： 2013.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：安田女子大学、広島市   Country：Japan  

Event date： 2013.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：安田女子大学、広島市   Country：Japan  

Event date： 2012.12

Presentation type：Oral presentation (general)  

Venue：川崎医科大学図書館小講堂（倉敷市）   Country：Japan  

Muscle regeneration dynamics mediated by resident myogenic stem cells
Authored by Ryuichi Tatsumi, Kyushu Univ., Fukuoka, JAPAN

Skeletal muscle regeneration and work-induced hypertrophy are initiated by mechanical insult or other perturbation and one of the earliest events is triggering the activation (re-entry to cell cycle from G0) of quiescent resident myogenic stem cells, satellite cells. Recent studies of satellite cells in culture and in vivo addressed the possible dual-roles of hepatocyte growth factor (HGF) in the stretch-induced activation and the re-establishing quiescence. In the proposed scenario, the time-coordinated increase in extracellular HGF is a key modulator for the two contrary pathways having low and high thresholds to impact activation and the counterpart quiescence of satellite cells, respectively. Moreover, the role of HGF in muscle repair may not be restricted to myogenesis; we demonstrated that HGF up-regulates expression of secreted axon-guidance molecule semaphorin 3A (Sema3A) in satellite cells at early-differentiation phase in primary cultures and in vivo. The results encourage a possible implication of satellite cells in the spatiotemporal regulation of extracellular Sema3A concentrations, which potentially mediates restoration or remodeling of nerve-muscle connections in muscle regeneration in synchrony with recovery of muscle-fiber integrity and types (fast and slow). Overall our results highlight the “programmed mechano-biology dynamics” that successful muscle regeneration, comprised of satellite cell-driving myogenesis and intramuscular moto-neuritogenesis, may be a programmed sequence of events that respond to a mechanical perturbation in a synchronous, HGF-dependent and time-coordinated manner.

Event date： 2012.12

Presentation type：Symposium, workshop panel (public)  

Venue：福岡国際会議場（福岡市）   Country：Japan  

Programmed mechano-biology of resident myogenic stem cells
Authored by Ryuichi Tatsumi, Kyushu Univ., Fukuoka, JAPAN

Skeletal muscle regeneration and work-induced hypertrophy are initiated by mechanical insult or other perturbation and one of the earliest events is triggering the activation (re-entry to cell cycle from G0) of quiescent resident myogenic stem cells, satellite cells. Recent studies of satellite cells in culture and in vivo addressed the possible dual-roles of hepatocyte growth factor (HGF) in the stretch-induced activation and the re-establishing quiescence. In the proposed scenario, the time-coordinated increase in extracellular HGF is a key modulator for the two contrary pathways having low and high thresholds to impact activation and the counterpart quiescence of satellite cells, respectively. Moreover, the role of HGF in muscle repair may not be restricted to myogenesis; we demonstrated that HGF up-regulates expression of secreted axon-guidance molecule semaphorin 3A (Sema3A) in satellite cells at early-differentiation phase in primary cultures and in vivo. The results encourage a possible implication of satellite cells in the spatiotemporal regulation of extracellular Sema3A concentrations, which potentially mediates restoration or remodeling of nerve-muscle connections in muscle regeneration in synchrony with recovery of muscle-fiber integrity. Overall our results highlight the “programmed mechano-biology” that successful muscle regeneration, comprised of satellite cell-driving myogenesis and intramuscular moto-neuritogenesis, may be a programmed sequence of events that respond to a mechanical perturbation in a synchronous, HGF-dependent and time-coordinated manner.

Event date： 2012.12

Presentation type：Oral presentation (general)  

Venue：JA共済ビル カンファエレンス・ホール（東京都千代田区）   Country：Japan  

Event date： 2012.8

Presentation type：Oral presentation (general)  

Venue：Renaissance Tuscany Il Ciocco Resort & Spa, Barga, Lucca, Italy   Country：Italy  

When skeletal muscle is stretched or injured, satellite cells, resident myogenic stem cells positioned beneath the basal lamina of mature muscle fibers, are activated to enter the cell cycle. This signaling pathway is a cascade of events including calcium-calmodulin formation, nitric oxide (NO) radical production by NO synthase, matrix metalloproteinase activation, release of hepatocyte growth factor (HGF) from the extracellular matrix, and presentation of HGF to the receptor c-met, as demonstrated by assays of primary cultures and in vivo experiments. Here, we add evidence that two ion channels, the mechano-sensitive cation channel (MS-channel) and the long-lasting-type voltage-gated calcium-ion channel (L-VGC-channel), mediate the influx of extracellular calcium ions in response to cyclic stretch in satellite-cell cultures. When applied to 1-hr stretch cultures with individual inhibitors for MS- and L-VGC-channels (GsMTx-4 and nifedipine, respectively) or with a less specific inhibitor for MS-channels (gadolinium chloride, Gd), satellite cell activation and upstream HGF release were abolished, as revealed by bromodeoxyuridine-incorporation assays and western blotting of conditioned media, respectively. The inhibition was dose-dependent with a maximum at 0.1 μM (GsMTx-4), 10 μM (nifedipine) or 100 μM (Gd) and cancelled by addition of HGF to the culture media; a potent inhibitor for transient-type VGC-channels (NNC55-0396, 100 μM) did not show any significant inhibitory effect. The stretch response was also abolished when calcium-chelator EGTA (1.8 mM) was added to the medium, indicating the significance of extracellular free calcium ions in our present activation model. Finally, cation/calcium channel dependencies were further documented by calcium-imaging analyses on stretched cells; results clearly demonstrated that calcium ion influx was abolished by GsMTx-4, nifedipine and EGTA. Therefore, these results provide an additional insight that calcium ions may flow in through L-VGC-channels by possible coupling with adjacent MS-channel gating that promotes the local depolarization of cell membranes to impact the satellite cell activation cascade.

Key Words: Calcium ion influx; Mechano-sensitive channel; Muscle regeneration; Satellite cells; Stretch-activation; Voltage-gated channel

Event date： 2012.8

Presentation type：Symposium, workshop panel (public)  

Venue：Renaissance Tuscany Il Ciocco Resort & Spa, Barga, Lucca, Italy   Country：Italy  

Semaphorin 3A (Sema3A, also referred to as SemaIII, SemD and collapsin), a class 3 vertebrate-secreted semaphorin, is a potent axon-guidance cue for sensory, sympathetic and motor axons. Recently, we found that satellite cells up- or down-regulate Sema3A in time-dependent responses to in vivo muscle crush-injury and in vitro treatment with recombinant HGF, FGF2 or TGF-βs. Such responses imply that satellite cells are involved in regenerative motoneuritogenesis, including sprouting and re-attachment of motoneuron terminals onto damaged muscle fibers. In order to explore the mechanism of HGF/FGF2-induced Sema3A up-regulation, the present study was designed to investigate possible membrane receptors that are present on satellite cells and could be involved in that signaling pathway. First, we tested whether c-met and FGFR1, high-affinity receptors of HGF and FGF2 respectively, are responsible for Sema3A up-regulation. Treatment with anti-c-met and anti-FGFR1 neutralizing antibodies did not diminish Sema3A up-regulation, indicating that c-met and FGFR1 may not mediate the response. In addition to such high-affinity receptors, HGF and FGF2 also bind with lower affinity to glycosaminoglycan (GAG) chains of proteoglycans - an important component of extracellular matrix- for a variety of biological functions. We therefore hypothesized that the association between HGF/FGF2 and GAG chains might mediate the Sema3A up-regulation. To test the hypothesis, satellite cell cultures were pretreated with GAG-degrading enzymes before the addition of HGF or FGF2, and the level of Sema3A expression was quantified by real-time qPCR. Results showed that treatment with heparitinase for partial removal of heparan sulfate chains significantly decreased induction of Sema3A up-regulation by HGF, but not FGF2. Similarly, treatment with chondroitinase ABC for partial removal of chondroitin sulfate chains significantly diminished the Sema3A up-regulation induced by FGF2, but not HGF. These results suggest that HGF and FGF2 bind to receptors carrying heparan and/or chondroitin sulfate chains; syndecans or other transmembrane-type proteoglycans appear to be plausible receptor candidates for signaling via growth factors to up-regulate Sema3A in satellite cells in culture.

Event date： 2012.8

Presentation type：Symposium, workshop panel (public)  

Venue：Renaissance Tuscany Il Ciocco Resort & Spa, Barga, Lucca, Italy   Country：Italy  

Semaphorin 3A (Sema3A), a class 3 vertebrate-secreted semaphorin, is a potent axon-guidance molecule for sensory, sympathetic and motor neurons. Recently, we found that resident myogenic stem cells, satellite cells, up-regulate Sema3A expression and secretion exclusively at the early-myogenic differentiation phase in response to in vivo crush injury and HGF/FGF2 treatments in the primary cultures, suggesting possible implication of satellite cells in regenerative motoneuritogenesis including sprouting and attachment of motoneuron terminals onto damaged muscle fibers in synchrony with recovery of muscle-fiber structures (Tatsumi et al., Am. J. Physiol. Cell Physiol. 2009; Do et al., Am. J. Physiol. Cell Physiol. 2011). Here, we show that Sema3A also mediates post-natal myogenesis by stimulating the early differentiation of satellite cells. When recombinant Sema3A (R&D Systems) was added to satellite cell cultures for 24 hr from 48-hr post-plating, myogenin message (an early differentiation marker) was up-regulated in a dose-dependent manner with a maximum at 10 ng/ml. Sema3A-specific knock-down by RNAi technique (about 60-75% reduction efficiency) remarkably down-regulated myogenin expression at message and protein levels at the early-differentiation stage, however showed no significant effect on MyoD expression at the same phase and myosin heavy chain expression and myotube formation at the later stage. Immunofluorescence analysis revealed the presence of Sema3A membrane-receptor neuropilin1 (Npn1) at 48-hr post-plating, which is the early-differentiation time-point which siRNA was transfected to cells; immunoneutralization of Npn1 activity also reduced the myogenin expression, which can be rescued competitively by co-addition of Sema3A protein, to a level equivalent to control cultures without anti-Npn1 antibody and Sema3A. These results indicate that satellite cell-secreted Sema3A may bind to the receptor Npn1 to generate myogenin expression signaling that stimulates early differentiation of satellite cells in autocrine and/or paracrine fashions. This topic may be supported potentially by our comparative observations that rat soleus muscle satellite cells showed higher expression activities of Sema3A, myogenin, and plexinA2 (a signaling co-receptor protein for Sema3A) than EDL muscle cells at the early-differentiation stage. Overall, the data highlight again a heretofore unexplored and active role for Sema3A as a key regulator of the early myogenic differentiation of satellite cells during muscle regeneration, therefore providing a better understanding of multi-functional contributions of Sema3A.

Event date： 2012.5 - 2012.3

Presentation type：Oral presentation (general)  

Venue：北海道大学大学院農学研究院（北海道札幌市）   Country：Japan  

Event date： 2012.3

Presentation type：Oral presentation (general)  

Venue：名古屋大学東山キャンパス   Country：Japan  

Event date： 2012.3

Presentation type：Oral presentation (general)  

Venue：名古屋大学東山キャンパス   Country：Japan  

Event date： 2012.3

Presentation type：Oral presentation (general)  

Venue：農業・食品産業技術総合研究機構 畜産草地研究所（茨城県つくば市池ノ台２）   Country：Japan  

Event date： 2011.12

Presentation type：Oral presentation (general)  

Venue：JA共済ビル カンファエレンス・ホール（東京都千代田区）   Country：Japan  

Do, Mai-Khoi Q., Sato, Y., Sankoda, Y., Shimizu, N., Suzuki, T., Mizunoya, W., Nakamura, M., Ikeuchi, Y., Judy E. Anderson, Ronald E. Allen (2011) Possible implication of myogenic stem cells in regenerative motoneuritogenesis through axon guidance molecule Sema3A expression and secretion, Group Meeting 2011 on Translational Research for Muscular Dystrophy (Dec. 1-2, 2011, Tokyo).

Event date： 2011.10

Presentation type：Symposium, workshop panel (public)  

Venue：群馬県前橋市ベイシア文化ホール／前橋商工会議所   Country：Japan  

Tatsumi, R. (2011) Possible implication of myogenic stem cells in regenerative motoneuritogenesis, The 26th Annual Research Meeting of the Japanese Orthopaedic Association (Oct. 20, 21th, 2011, Maebashi, Gunma).

Event date： 2011.9

Presentation type：Oral presentation (general)  

Venue：花王（株）生物科学研究所(栃木県芳賀郡 市貝町赤羽)   Country：Japan  

Event date： 2011.9

Presentation type：Oral presentation (general)  

Venue：花王（株）生物科学研究所(栃木県芳賀郡 市貝町赤羽)   Country：Japan  

Event date： 2011.8

Presentation type：Oral presentation (general)  

Venue：北里大学獣医学部十和田キャンパス(青森県十和田市）   Country：Japan  

Event date： 2011.8

Presentation type：Oral presentation (general)  

Venue：北里大学獣医学部十和田キャンパス(青森県十和田市）   Country：Japan  

Event date： 2011.8

Presentation type：Oral presentation (general)  

Venue：北里大学獣医学部十和田キャンパス(青森県十和田市）   Country：Japan  

Event date： 2011.8

Presentation type：Oral presentation (general)  

Venue：北里大学獣医学部十和田キャンパス(青森県十和田市）   Country：Japan  

Event date： 2011.8

Presentation type：Oral presentation (general)  

Venue：北里大学獣医学部十和田キャンパス(青森県十和田市）   Country：Japan  

Event date： 2011.8

Presentation type：Oral presentation (general)  

Venue：北里大学獣医学部十和田キャンパス(青森県十和田市）   Country：Japan  

Event date： 2011.3

Presentation type：Oral presentation (general)  

Venue：東京農業大学厚木キャンパス   Country：Japan  

Event date： 2011.3

Presentation type：Oral presentation (general)  

Venue：東京農業大学厚木キャンパス   Country：Japan  

Event date： 2011.3

Presentation type：Oral presentation (general)  

Venue：東京農業大学厚木キャンパス   Country：Japan  

Event date： 2011.2

Presentation type：Oral presentation (general)  

Venue：九州大学農学部大会議室   Country：Japan  

Event date： 2010.12

Presentation type：Public lecture, seminar, tutorial, course, or other speech  

Venue：北海道大学大学院農学研究院、札幌市   Country：Japan  

Event date： 2010.8

Presentation type：Oral presentation (general)  

Venue：National Pingtung University of Science and Technology, Taiwan   Country：Taiwan, Province of China  

Event date： 2010.8

Presentation type：Symposium, workshop panel (public)  

Venue：Suntec Convention and Exhibition Center, Singapore   Country：Singapore  

物理刺激を引き金として肝細胞増殖因子HGF依存的に筋幹細胞（衛星細胞）が活性化する分子機構に関して招待講演を行った。

Event date： 2010.8

Presentation type：Symposium, workshop panel (public)  

Venue：Suntec Convention and Exhibition Center, Singapore   Country：Singapore  

Event date： 2010.7

Presentation type：Symposium, workshop panel (public)  

Venue：Carefree Resort, Carefree, AZ, USA   Country：United States  

Event date： 2010.7

Presentation type：Symposium, workshop panel (public)  

Venue：Carefree Resort, Carefree, AZ, USA   Country：United States  

Event date： 2010.3

Presentation type：Oral presentation (general)  

Venue：明治大学駿河台キャンパス   Country：Japan  

Event date： 2010.3

Presentation type：Oral presentation (general)  

Venue：明治大学駿河台キャンパス   Country：Japan  

Event date： 2010.3

Presentation type：Oral presentation (general)  

Venue：明治大学駿河台キャンパス   Country：Japan  

Event date： 2009.10

Venue：大分県農林水産研究センター 豊後大野管理部会議室   Country：Japan  

Event date： 2009.9

Presentation type：Oral presentation (general)  

Venue：琉球大学（那覇市）   Country：Japan  

Event date： 2009.9

Presentation type：Oral presentation (general)  

Venue：琉球大学（那覇市）   Country：Japan  

Event date： 2009.9

Presentation type：Oral presentation (general)  

Venue：琉球大学（那覇市）   Country：Japan  

Event date： 2009.9

Presentation type：Oral presentation (general)  

Venue：琉球大学（那覇市）   Country：Japan  

Event date： 2009.9

Presentation type：Oral presentation (general)  

Venue：琉球大学（那覇市）   Country：Japan  

Event date： 2009.3

Presentation type：Symposium, workshop panel (public)  

Venue：福岡国際会議場・マリンメッセ福岡（福岡市）   Country：Japan  

Event date： 2008.12

Presentation type：Symposium, workshop panel (public)  

Venue：Moscone Center, San Francisco, CA   Country：United States  

Event date： 2008.3

Presentation type：Oral presentation (general)  

Venue：常磐大学（水戸市）   Country：Japan  

Event date： 2008.3

Presentation type：Oral presentation (general)  

Venue：常磐大学（水戸市）   Country：Japan  

Presentation type：Symposium, workshop panel (public)  

Venue：Rome   Country：Italy  

Takehiro Ogawa, Toshiya Hayashi, Kazumasa Nodake, Shohei Shiraishi, Sunao Mori, Ryuichi Tatsumi,, Yoshihide Ikeuchi and Tatsumi Ito, A Novel Muscle Cell Growth Factor, S-Myotrophin, Promotes the Expression of Fast Myosin in Myotubes Developed from C2C12 Cells., 48th International Congress of Meat Science and Technology, Rome, Italy (August 25-30, 2002).

Presentation type：Oral presentation (general)  

Venue：Banff, Alberta   Country：Canada  

Ronald E. Allen and Ryuichi Tatsumi, Satellite Cell Activation in Response to Muscle Damage., Molecular Biology of Muscle Development and Regeneration,
The Banff Centre, Alberta, Canada (May 30-June 4, 2003), invited speak.

Presentation type：Oral presentation (general)  

Venue：Tucson, AZ   Country：United States  

Ryuichi Tatsumi and Ronald E. Allen, Satellite Cell Activation in Response to Muscle Stretch and Damage., FASEB Summer Research Conference 2003, 3rd International Conference on Muscle Satellite & Stem Cells, Omni Tucson Golf Resort & Spa, Tucson, AZ, US (July 26-30, 2003), invited speak.

Presentation type：Oral presentation (general)  

Venue：日本大学生物資源科学部（藤沢市）   Country：Japan  

Tatsumi, R., Ikeuchi, Y., and Hattori, A. (2004) Molecular Mechanism of Muscle Satellite Cell Activation: Mechanical Perturbation triggers Nitric Oxide-Dependent Cascade., the 137th Annual Meeting of Japanese Society of Veterinary Science.

Presentation type：Oral presentation (general)  

Venue：東京大学農学部（東京都）   Country：Japan  

Tatsumi, R., Yamanouchi, K., Hosoyama, T., Ikeuchi, Y. (2005) Activation Factor HGF Induces Satellite Cell Quiescence In Vitro., the 104th Annual Meeting of Japan Society of Animal Science.

Presentation type：Oral presentation (general)  

Venue：東京農工大学農学部（府中市）   Country：Japan  

Tatsumi, R., Ikeuchi, Y. (2005) More Shine to Meat Production: A Programmed Cascade Model for Muscle Satellite Cell Activation and Quiescence., the Annual Spring Meeting 2005 of Japanese Society for Animal Nutrition and Metabolism.

Presentation type：Symposium, workshop panel (public)  

Venue：Tucson, AZ   Country：United States  

Ryuichi Tatsumi, Keitaro Yamanouchi, Toru Hosoyama, Sei-ichi Shiratsuchi, Michiko Yamada, Jun-Ichiro Wakamatsu, Wataru Mizunoya, Yoshihide Ikeuchi, and Ronald E. Allen, A Possible Programmed Mechanism of Muscle Satellite Cell Quiescence: The cell Activator HGF Induces Myostatin Expression and Secretion., FASEB Summer Research Conference 2005, 4rd International Conference on Skeletal Muscle & Stem Cells, Omni Tucson Golf Resort & Spa, Tucson, AZ, US (June 11-16, 2005)

Presentation type：Oral presentation (general)  

Venue：九州大学六本松キャンパス   Country：Japan  

Tatsumi R. (2006) Mechanobiology of Skeletal Muscle Satellite Cells., the 10th Annual Symposium on Animal Life Sciences., invited talk

Presentation type：Oral presentation (general)  

Venue：九州大学六本松キャンパス   Country：Japan  

Tatsumi R. (2006) Myostatin Expression in Myogenic Stem cells., Symposium of the 106th Annual Meeting of Japan Society of Animal Science., invited talk

Presentation type：Oral presentation (general)  

Venue：九州大学六本松キャンパス   Country：Japan  

Okamoto, S., Wakamatsu, J.-I., Mizunoya, W., Waga, T., Tatsumi, R., Ikeuchi, Y. (2006) Effects of Apple-Polyphenol Intake on Rat Skeletal Muscle and Lipid Metabolism., the 106th Annual Meeting of Japan Society of Animal Science.

Presentation type：Symposium, workshop panel (public)  

Venue：Callaway Gardens, Pine Mountain, GA   Country：United States  

Presentation type：Public lecture, seminar, tutorial, course, or other speech  

Venue：北海道大学大学院獣医科学研究科（札幌市）   Country：Japan  

Ryuichi Tatsumi, Mechanobiology on muscle hypertrophy and regeneration: HGF/NO-dependent cascade model of satellite cell activation and quiescence mechanism. Lecture at the Graduate School of Veterinary Science, Hokkaido University, Feb. 1st., 2007.

Presentation type：Symposium, workshop panel (public)  

Venue：Meridian, Indianapolis, Indiana 46204, USA   Country：United States  

Presentation type：Symposium, workshop panel (public)  

Venue：Meridian, Indianapolis, Indiana 46204, USA   Country：United States  

Presentation type：Oral presentation (general)  

Venue：Indian Wells, CA, USA   Country：United States  

Presentation type：Oral presentation (general)  

Venue：岡山大学（岡山市）   Country：Japan  

Presentation type：Symposium, workshop panel (public)  

Venue：Tucson, AZ   Country：United States  

Ryuichi Tatsumi, Tomowa Sakata, Shannon M. Sheehan, Akihito Hattori and Ronald E. Allen, Mechanical Stretch-Induced Activation of Skeletal Muscle Satellite Cells: the Possible Role of HGF in the Mechanism., FASEB Summer Research Conference 2000, 2nd International Conference on Muscle Satellite & Stem Cells,
Omni Tucson Golf Resort & Spa, Tucson, AZ, US (July 14-19, 2001).

Presentation type：Symposium, workshop panel (public)  

Venue：Aspen, CO   Country：United States  

Ronald. E. Allen, Ryuichi Tatsumi, and Shannon M. Sheehan, HGF is the Activating Factor in Crushed Muscle Extract and Is an Autocrine Growth Factor for Satellite Cells., 1997 Keystone Symposia on Molecular and Cellular Biology, Molecular Biology of Muscle Development, Aspen, CO, US (April 1-6, 1997).

Presentation type：Oral presentation (general)  

Venue：Boston   Country：United States  

Ronald. E. Allen and Ryuichi Tatsumi, Satellite Cell Activation and the Role of Hepatocyte Growth Factor/Scatter Factor., Post-natal Myogenesis: Satellite Cells in Action, Boston, US (August 13-16, 1998)., invited speak.

Presentation type：Symposium, workshop panel (public)  

Venue：Yokohama   Country：Japan  

Yukiko Ito, Ryuichi Tatsumi, Takanori Nishimura and Akihito Hattori,
Solubilization of Myofibrillar Proteins of Chicken Skeletal Muscle in Water., 45th International Congress of Meat Science and Technology, Yokohama, Japan (August 1-6, 1999).

Presentation type：Symposium, workshop panel (public)  

Venue：Yokohama   Country：Japan  

Ryuichi Tatsumi, Kenji Maeda and Koui Takahashi, (1999) Calcium-Induced Splitting of Connectin/Titin Filaments: Localization and Characterization of Calcium-Binding Sites., 45th International Congress of Meat Science and Technology, Yokohama, Japan (August 1-6, 1999).

Presentation type：Symposium, workshop panel (public)  

Venue：Asilomar, CA   Country：United States  

Ryuichi Tatsumi, Shannon M. Sheehan, Hiroyuki Iwasaki, Akihito Hattori and Ronald E. Allen, Mechanical Stretch Induces Activation of Skeletal Muscle Satellite Cells In Vitro., 2000 Keystone Symposia on the Molecular Biology of Muscle Development and Disease, Asilomar, CA, US (May 21-26, 2000).

Event date： 2024.7

Language：English   Presentation type：Poster presentation  

Venue：Estérel, Quebec, Canada   Country：Canada  

Event date： 2024.2

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京医科大学新宿キャンパス、東京都   Country：Japan  

Event date： 2023.11

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：シーガイアコンベンションセンター、宮崎市   Country：Japan  

Event date： 2023.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：帯広畜産⼤学、帯広市   Country：Japan  

Event date： 2023.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：帯広畜産⼤学、帯広市   Country：Japan  

Event date： 2023.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：帯広畜産⼤学、帯広市   Country：Japan  

Event date： 2023.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：帯広畜産⼤学、帯広市   Country：Japan  

Event date： 2023.9

Language：English   Presentation type：Oral presentation (general)  

Venue：ポーツマス   Country：United Kingdom  

Event date： 2023.8

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：千里ライフサイエンスセンター、豊中市   Country：Japan  

Event date： 2023.8

Language：English   Presentation type：Oral presentation (general)  

Venue：千里ライフサイエンスセンター、豊中市   Country：Japan  

Event date： 2023.5

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：札幌コンベンションセンター、札幌市   Country：Japan  

Event date： 2022.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン開催（東京農業大学）   Country：Japan  

Event date： 2022.8

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：オンライン開催   Country：Other  

Event date： 2022.8

Language：English   Presentation type：Oral presentation (general)  

Venue：オンライン開催   Country：Other  

Event date： 2022.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン開催   Country：Japan  

Event date： 2022.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン開催   Country：Japan  

Event date： 2021.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：京都大学 百周年時計台記念館 【ハイブリッド開催】   Country：Japan  

Event date： 2021.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：京都大学 百周年時計台記念館 【ハイブリッド開催】   Country：Japan  

Event date： 2021.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：京都大学 百周年時計台記念館 【ハイブリッド開催】   Country：Japan  

Event date： 2021.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：京都大学 百周年時計台記念館 【ハイブリッド開催】   Country：Japan  

Event date： 2021.12

Language：English   Presentation type：Oral presentation (general)  

Venue：京都大学 百周年時計台記念館 【ハイブリッド開催】   Country：Japan  

Event date： 2021.12

Language：English   Presentation type：Oral presentation (general)  

Venue：オンライン開催   Country：Other  

Event date： 2021.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン開催   Country：Japan  

Event date： 2021.3

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：オンライン   Country：Japan  

Event date： 2021.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2021.3

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：オンライン   Country：Japan  

Event date： 2021.3

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：オンライン   Country：Japan  

Event date： 2021.3

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：オンライン   Country：Japan  

Event date： 2021.3

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：オンライン   Country：Japan  

Event date： 2021.3

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：オンライン   Country：Japan  

Event date： 2021.3

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：オンライン   Country：Japan  

Event date： 2021.3

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：オンライン   Country：Japan  

Event date： 2021.3

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：オンライン   Country：Japan  

Event date： 2021.3

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：オンライン   Country：Japan  

Event date： 2020.12

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：オンライン   Country：Japan  

Event date： 2020.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：京都大学、京都市   Country：Japan  

Event date： 2019.12

Language：English   Presentation type：Oral presentation (general)  

Venue：Walter E. Washington Convention Center, Washington, DC,   Country：United States  

Event date： 2019.12

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：福岡国際会議場・マリンメッセ福岡、福岡市   Country：Japan  

Event date： 2019.11

Language：English   Presentation type：Oral presentation (general)  

Venue：米子コンベンションセンターBIG SHIP、米子市   Country：Japan  

Event date： 2019.11

Language：English   Presentation type：Oral presentation (general)  

Venue：米子コンベンションセンターBIG SHIP、米子市   Country：Japan  

Event date： 2019.11

Language：English   Presentation type：Oral presentation (general)  

Venue：米子コンベンションセンターBIG SHIP、米子市   Country：Japan  

Event date： 2019.9

Language：English   Presentation type：Oral presentation (general)  

Venue：Marriott San José, San José   Country：Costa Rica  

Event date： 2019.9

Language：English   Presentation type：Oral presentation (general)  

Venue：Marriott San José, San José   Country：Costa Rica  

Event date： 2019.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：岩手大学、盛岡市   Country：Japan  

Event date： 2019.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：岩手大学、盛岡市   Country：Japan  

Event date： 2019.8

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：伊藤国際学術研究センター、東京都文京区   Country：Japan  

Event date： 2019.8

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：伊藤国際学術研究センター、東京都文京区   Country：Japan  

Event date： 2019.8

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：伊藤国際学術研究センター、東京都文京区   Country：Japan  

Event date： 2018.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：長崎ウエスレヤン大学、諫早市   Country：Japan  

Event date： 2018.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：長崎ウエスレヤン大学、諫早市   Country：Japan  

Event date： 2018.8

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：川崎医科大学、倉敷市   Country：Japan  

Event date： 2018.8

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：川崎医科大学、倉敷市   Country：Japan  

Event date： 2018.8

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：川崎医科大学、倉敷市   Country：Japan  

Event date： 2018.7

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：Steamboat Springs, CO  

Event date： 2018.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：岡山県立大学、総社市   Country：Japan  

Event date： 2018.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：麻布大学、相模原市   Country：Japan  

Event date： 2018.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京大学、東京都   Country：Japan  

Event date： 2018.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京大学、東京都   Country：Japan  

Event date： 2018.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京大学、東京都   Country：Japan  

Event date： 2018.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：麻布大学、相模原市   Country：Japan  

Event date： 2018.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：麻布大学、相模原市   Country：Japan  

Event date： 2018.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：麻布大学、相模原市   Country：Japan  

Event date： 2018.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：麻布大学、相模原市   Country：Japan  

Event date： 2017.12

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：神戸ポートアイランド、神戸市   Country：Japan  

Event date： 2017.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Kyushu University   Country：Japan  

Event date： 2017.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：神戸大学、神戸市   Country：Japan  

Event date： 2017.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：神戸大学、神戸市   Country：Japan  

Event date： 2017.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：神戸大学、神戸市   Country：Japan  

Event date： 2017.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：神戸大学、神戸市   Country：Japan  

Event date： 2017.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：神戸大学、神戸市   Country：Japan  

Event date： 2016.8

Language：English   Presentation type：Oral presentation (general)  

Venue：Kyushu Sangyo University   Country：Japan  

Event date： 2016.8

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：Kyushu Sangyo University   Country：Japan  

Event date： 2016.8

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：Kyushu Sangyo University   Country：Japan  

Event date： 2016.8

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：Kyushu Sangyo University   Country：Japan  

Event date： 2016.8

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：Kyushu Sangyo University   Country：Japan  

Event date： 2016.6

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：Asilomar Conference Grounds, Pacific Grove   Country：United States  

Event date： 2016.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：武庫川女子大学中央キャンパス（兵庫県西宮市）   Country：Japan  

Event date： 2016.5

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：武庫川女子大学中央キャンパス（兵庫県西宮市）   Country：Japan  

Event date： 2016.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：武庫川女子大学中央キャンパス（兵庫県西宮市）   Country：Japan  

Event date： 2016.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：日本獣医生命科学大学、武蔵野市   Country：Japan  

Event date： 2016.3

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：日本獣医生命科学大学、武蔵野市   Country：Japan  

Event date： 2016.3

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：日本獣医生命科学大学、武蔵野市   Country：Japan  

Event date： 2016.3

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：日本獣医生命科学大学、武蔵野市   Country：Japan  

Event date： 2015.12

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：神戸ポートアイランド、神戸市   Country：Japan  

Event date： 2015.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：九州大学病院キャンパス（福岡市）   Country：Japan  

Event date： 2015.11

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：九州大学病院キャンパス（福岡市）   Country：Japan  

Event date： 2015.11

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：九州大学病院キャンパス（福岡市）   Country：Japan  

Event date： 2015.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：酪農学園大学（江別市）   Country：Japan  

Event date： 2015.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：酪農学園大学（江別市）   Country：Japan  

Event date： 2015.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：酪農学園大学（江別市）   Country：Japan  

Event date： 2015.8

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：国立研究開発法人国立精神・神経医療研究センター（小平市）   Country：Japan  

Event date： 2015.8

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：国立研究開発法人国立精神・神経医療研究センター（小平市）   Country：Japan  

Event date： 2015.5

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：PACIFICO Yokohama   Country：Japan  

Event date： 2015.5

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：PACIFICO Yokohama   Country：Japan  

Event date： 2015.5

Language：English   Presentation type：Oral presentation (general)  

Venue：PACIFICO Yokohama   Country：Japan  

Event date： 2015.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：宇都宮大学、宇都宮市   Country：Japan  

Event date： 2015.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：宇都宮大学、宇都宮市   Country：Japan  

Event date： 2015.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：宇都宮大学、宇都宮市   Country：Japan  

Event date： 2014.11

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：パシフィコ横浜、横浜市   Country：Japan  

Event date： 2014.10

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：Ladena Condominium   Country：Korea, Republic of  

Event date： 2014.7

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：Steamboat Springs   Country：United States  

Event date： 2014.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：九州大学システム生命科学府講義棟, 福岡市   Country：Japan  

Event date： 2014.5 - 2014.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：酪農学園大学（江別）   Country：Japan  

Event date： 2014.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：つくば国際会議場、つくば市   Country：Japan  

Event date： 2014.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：つくば国際会議場、つくば市   Country：Japan  

Event date： 2014.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：つくば国際会議場、つくば市   Country：Japan  

Event date： 2014.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：つくば国際会議場、つくば市   Country：Japan  

Event date： 2014.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：つくば国際会議場、つくば市   Country：Japan  

Event date： 2013.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：新潟大学、新潟市   Country：Japan  

Event date： 2013.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：新潟大学、新潟市   Country：Japan  

Event date： 2013.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：名古屋大学（名古屋市）   Country：Japan  

Event date： 2013.4

Language：English   Presentation type：Oral presentation (general)  

Venue：Alpbach Congress Centrum, Alpbach   Country：Austria  

Event date： 2013.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：安田女子大学、広島市   Country：Japan  

Event date： 2013.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：安田女子大学、広島市   Country：Japan  

Event date： 2013.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：安田女子大学、広島市   Country：Japan  

Event date： 2013.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：安田女子大学、広島市   Country：Japan  

Event date： 2012.12

Presentation type：Oral presentation (general)  

Venue：福岡国際会議場（福岡市）   Country：Japan  

Event date： 2012.12

Presentation type：Symposium, workshop panel (public)  

Venue：福岡国際会議場（福岡市）   Country：Japan  

Event date： 2012.12

Presentation type：Oral presentation (general)  

Venue：JA共済ビル カンファエレンス・ホール（東京都千代田区）   Country：Japan  

Event date： 2012.8

Presentation type：Symposium, workshop panel (public)  

Venue：Renaissance Tuscany Il Ciocco Resort & Spa, Barga, Lucca, Italy   Country：Italy  

Event date： 2012.8

Presentation type：Symposium, workshop panel (public)  

Venue：Renaissance Tuscany Il Ciocco Resort & Spa, Barga, Lucca, Italy   Country：Italy  

APOBEC2 is one a member of AID/APOBEC cytidine deaminase family with putative DNA/RNA editing enzyme. Loss of APOBEC2 leads to a shift in muscle fiber-type, diminished body mass and myofiber with centrally-located nuclei although the molecular mechanisms are unknown. APOBEC2 is localized in z-bands of sarcomere in mouse muscle. Its deficiency did not affect the sarcomere structure although skeletal muscles of APOBEC2 KO (A2-/-) mice had degenerating fibers and rimmed vacuoles (RVs). To test whether the defect of APOBEC2 affected protein degradation system, we investigated the expression level of autophagy-related genes (Map1lc3b, Park2, Pink1 and p62) and ubiquitin ligases (Trim63, Fbxo32). The expression levels of autophagy-related genes were increased although those of ubiquitin ligases were not changed. Immunohistochemical analysis showed accumulated LC3 and p62 in RVs of A2-/- myofiber. Subsequent electron microscopy showed enlarged mitochondria and mitochondria engulfed by autophagosomes in A2-/- muscle. In addition, we found that activated LC3-Ⅱ and poly-ubiquitin were increased and localized to mitochondria of A2-/- muscle. In this study, we demonstrated that APOBEC2 deficiency caused enlarged mitochondria and increased autophagy (especially mitophagy). APOBEC2 may be unknown autophagy-related gene in skeletal muscle.

Event date： 2012.3

Presentation type：Oral presentation (general)  

Venue：名古屋大学東山キャンパス   Country：Japan  

Event date： 2011.8

Presentation type：Oral presentation (general)  

Venue：北里大学獣医学部十和田キャンパス(青森県十和田市）   Country：Japan  

Event date： 2011.5

Presentation type：Oral presentation (general)  

Venue：お茶の水女子大学（東京）   Country：Japan  

Mizunoya, Y., Shimomura, K., Tatsumi, R., and Ikeuchi, Y. (2011) Dietary soy isoflavones alter skeletal muscle fiber type in rats, The 65th Annual Research Meeting of Japanese Society of Nutrition and Food Science (May 13-15, 2011, Ochanomizu University, Tokyo).

Event date： 2011.3

Presentation type：Oral presentation (general)  

Venue：東京農業大学厚木キャンパス   Country：Japan  

Event date： 2011.3

Presentation type：Oral presentation (general)  

Venue：東京農業大学厚木キャンパス   Country：Japan  

Event date： 2010.5

Venue：徳島   Country：Japan  

Event date： 2010.3

Presentation type：Oral presentation (general)  

Venue：明治大学駿河台キャンパス   Country：Japan  

Event date： 2009.9

Presentation type：Oral presentation (general)  

Venue：琉球大学（那覇市）   Country：Japan  

Event date： 2009.7

Presentation type：Oral presentation (general)  

Venue：独立行政法人 産業技術総合研究所臨海副都心センター（新潟市）   Country：Japan  

The development of healthy meat foods using high pressur processing

Event date： 2009.6

Presentation type：Oral presentation (general)  

Venue：ホテルニューオータニ長岡（長岡市）   Country：Japan  

Event date： 2009.3

Presentation type：Symposium, workshop panel (public)  

Venue：福岡国際会議場・マリンメッセ福岡（福岡市）   Country：Japan  

Event date： 2008.3

Presentation type：Oral presentation (general)  

Venue：常磐大学（水戸市）   Country：Japan  

Event date： 2008.3

Presentation type：Oral presentation (general)  

Venue：常磐大学（水戸市）   Country：Japan  

Event date： 2008.3

Presentation type：Oral presentation (general)  

Venue：常磐大学（水戸市）   Country：Japan  

Presentation type：Symposium, workshop panel (public)  

Venue：日本獣医畜産大学（武蔵野市）   Country：Japan  

Ikeuchi, Y., Nakanishi, A., Tatsumi, R., Ito, T., Tabata, M., Katayama, S., and Turu, T. (2002) Meat Quality of Bovine Thigh Muscle Subjected to Alkaline Solution Injection., the 100th Annual Meeting of Japan Society of Animal Science.

Presentation type：Symposium, workshop panel (public)  

Venue：日本獣医畜産大学（武蔵野市）   Country：Japan  

Tatsumi, R., Ikeuchi, Y., Ito, T., and Hattori, A. (2002) Role of Nitric Oxide in Stretch-Induced Activation of Skeletal Muscle Satellite Cells., the 100th Annual Meeting of Japan Society of Animal Science.

Presentation type：Oral presentation (general)  

Venue：つくば国際会議場（つくば市）   Country：Japan  

Yoshihara, H., Ikeuchi, Y., Kawabata, F., Haruno, A., Mori, S., Tatsumi, R., Ito, T., and Hayashi, T. (2003) Effect of Beef Extract Diet and Exercise on Lipid Metabolism and Muscle Fiber Types of Rat., the 44th Annual Meeting of Japan Society for Meat Science and Technology.

Presentation type：Oral presentation (general)  

Venue：東京農工大学府中キャンパス（府中市）   Country：Japan  

Haruno, A., Mori, S., Tatsumi, R., Ikeuchi, Y., Ito, T., Uechi, T. (2004) Effect of Curcumin Diet on Lipid Metabolism in Rat., the 103th Annual Meeting of Japan Society of Animal Science.

Presentation type：Oral presentation (general)  

Venue：東京農工大学府中キャンパス（府中市）   Country：Japan  

Ikeuchi, Y., Mori, S., Arai, Y., Tatsumi, R., Ito, T., Yoshioka, K., Yamamoto, S., and Suzuki, A. (2004) Stability of Rat Skeletal Muscle Myokinase Subjected to High Pressure Treatments., the 103th Annual Meeting of Japan Society of Animal Science.

Presentation type：Oral presentation (general)  

Venue：東京農工大学府中キャンパス（府中市）   Country：Japan  

Tatsumi, R., Wuollet, A.L., Ikeuchi, Y., Ito, T., and Allen, R.E. (2004) Calcium-Calmodulin Dependent Cascade of Muscle Satellite Cell Activation., the 103th Annual Meeting of Japan Society of Animal Science.

Presentation type：Oral presentation (general)  

Venue：JA・AZMホール（宮崎市）   Country：Japan  

Wakamatsu, J.-I., Shozaki, Y., Mori, S., Haruno, A., Sato, Y., Takemoto, K., Katsuki, Y., Ikeuchi, Y., and Tatsumi, R. (2004) Effect of Carnitine Diet on Lipid Metabolism and Muscle Fiber types of Rat, the 55th Annual Meeting of West Japan Society of Animal Science.

Presentation type：Oral presentation (general)  

Venue：JA・AZMホール（宮崎市）   Country：Japan  

Katsuki, Y., Mori, S., Haruno, A., Sato, Y., Takemoto, K., Wakamatsu, J.-I., Tatsumi, R., and Ikeuchi, Y. (2004) Preparation of Quiescent Satellite Cell Culture, the 55th Annual Meeting of West Japan Society of Animal Science.

Presentation type：Oral presentation (general)  

Venue：JA・AZMホール（宮崎市）   Country：Japan  

Tatsumi, R., Ikeuchi, Y., and Allen, R.E. (2004) Mechanical Stress-Induced Activation of Muscle Satellite Cells: Some Properties of Released HGF., the 55th Annual Meeting of West Japan Society of Animal Science.

Presentation type：Oral presentation (general)  

Venue：東京大学農学部（東京都）   Country：Japan  

Ikeuchi, y., Mori, S., Iguchi, R., Yokoyama, A., Tatsumi, R., Yamamoto, S., Suzuki, A. (2005) Pressure-Stability of Soluble 5'-Nucureotidase from Rabbit Skeletal Muscle., the 104th Annual Meeting of Japan Society of Animal Science.

Presentation type：Symposium, workshop panel (public)  

Venue：札幌コンベンションセンター（札幌市）   Country：Japan  

Tabata, M., Nishimura, S., Tatsumi, R., Ikeuchi, Y., Iwamoto, H. (2005) RyR3 Implicates in Calcium Influx in Chicken Myoblasts., the 105th Annual Meeting of Japan Society of Animal Science.

Presentation type：Symposium, workshop panel (public)  

Venue：札幌コンベンションセンター（札幌市）   Country：Japan  

Shiratsuchi, S., Yamada, M., Mizunoya, W., Tatsumi, R., Ikeuchi, Y. (2005) Molecular Mechanism for Myogenic Satellite Cell Quiescence: Myostatin Expression Mechanism., the 105th Annual Meeting of Japan Society of Animal Science.

Presentation type：Symposium, workshop panel (public)  

Venue：札幌コンベンションセンター（札幌市）   Country：Japan  

Wakamatsu, J.-I., Mizunoya, W., Tatsumi, R., Ikeuchi, Y., Sekiguchi, K. (2005) Studies on Muscle Hypertrophy Induced by Beef Extract., the 105th Annual Meeting of Japan Society of Animal Science.