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Hiroki Kato Last modified date:2021.10.29

Assistant Professor / Department of Dental Science, Faculty of Dental Science
Department of Dental Science
Faculty of Dental Science


Graduate School


Homepage
https://kyushu-u.pure.elsevier.com/en/persons/hiroki-kato
 Reseacher Profiling Tool Kyushu University Pure
Academic Degree
Doctor of Science
Field of Specialization
Cell biology
ORCID(Open Researcher and Contributor ID)
https://orcid.org/0000-0002-6529-659X
Total Priod of education and research career in the foreign country
02years06months
Research
Research Interests
  • Analysis of mitochondrial dynamics
    keyword : mitochondria, membrane dynamics
    2014.05~2030.12.
Academic Activities
Papers
1. Kentaro Nonaka, Xu Han, Hiroki Kato, Hiroshi Sato, Haruyoshi Yamaza, Yuta Hirofuji, Keiji Masuda, Novel gain-of-function mutation of TRPV4 associated with accelerated chondrogenic differentiation of dental pulp stem cells derived from a patient with metatropic dysplasia, Biochemistry and Biophysics Reports, 10.1016/j.bbrep.2019.100648, 19, 2019.09, Metatropic dysplasia is a congenital skeletal dysplasia characterized by severe platyspondyly, dumbbell-like deformity of long tubular bones, and progressive kyphoscoliosis with growth. It is caused by mutations in the gene TRPV4, encoding the transient receptor potential vanilloid 4, which acts as a calcium channel. Many heterozygous single base mutations of this gene have been associated with the disorder, showing autosomal dominant inheritance. Although abnormal endochondral ossification has been observed by histological examination of bone in a patient with lethal metatropic dysplasia, the etiology of the disorder remains largely unresolved. As dental pulp stem cells (DPSCs) are mesenchymal stem cells that differentiate into bone lineage cells, DPSCs derived from patients with congenital skeletal dysplasia might be useful as a disease-specific cellular model for etiological investigation. The purpose of this study was to clarify the pathological association between TRPV4 mutation and chondrocyte differentiation by analyzing DPSCs from a patient with non-lethal metatropic dysplasia. We identified a novel heterozygous single base mutation, c.1855C>T in TRPV4. This was predicted to be a missense mutation, p.L619F, in putative transmembrane segment 5. The mutation was repaired by CRISPR/Cas9 system to obtain isogenic control DPSCs for further analysis. The expression of stem cell markers and fibroblast-like morphology were comparable between patient-derived mutant and control DPSCs, although expression of TRPV4 was lower in mutant DPSCs than control DPSCs. Despite the lower TRPV4 expression in mutant DPSCs, the intracellular Ca2+ level was comparable at the basal level between mutant and control DPSCs, while its level was markedly higher following stimulation with 4α-phorbol 12,13-didecanoate (4αPDD), a specific agonist for TRPV4, in mutant DPSCs than in control DPSCs. In the presence of 4αPDD, we observed accelerated early chondrocyte differentiation and upregulated mRNA expression of SRY-box 9 (SOX9) in mutant DPSCs. Our findings suggested that the novel missense mutation c.1855C>T of TRPV4 was a gain-of-function mutation leading to enhanced intracellular Ca2+ level, which was associated with accelerated chondrocyte differentiation and SOX9 upregulation. Our results also suggest that patient-derived DPSCs can be a useful disease-specific cellular model for elucidating the pathological mechanism of metatropic dysplasia..
2. Huong Thi Nguyen Nguyen, Hiroki Kato, Hiroshi Sato, Haruyoshi Yamaza, Yasunari Sakai, Shoichi Ohga, Kazuaki Nonaka, Keiji Masuda, Positive effect of exogenous brain-derived neurotrophic factor on impaired neurite development and mitochondrial function in dopaminergic neurons derived from dental pulp stem cells from children with attention deficit hyperactivity disorder, Biochemical and Biophysical Research Communications, 10.1016/j.bbrc.2019.04.084, 2019.01, Attention deficit hyperactivity disorder (ADHD) is one of the most common neurodevelopmental disorders and is characterized by impaired attention, hyperactivity, and impulsivity. While multiple etiologies are implicated in ADHD, its underlying mechanism(s) remain unclear. Although previous studies have suggested dysregulation of dopaminergic signals, mitochondria, and brain-derived neurotrophic factor (BDNF) in ADHD, few studies have reported these associations directly. Stem cells from human exfoliated deciduous teeth (SHED) can efficiently differentiate into dopaminergic neurons (DNs) and are thus a useful disease-specific cellular model for the study of neurodevelopmental disorders associated with DN dysfunction. This study aimed to elucidate the relationships between DNs, mitochondria, and BDNF in ADHD by analyzing DNs differentiated from SHED obtained from three boys with ADHD and comparing them to those from three typically developing boys. In the absence of exogenous BDNF in the cell culture media, DNs derived from boys with ADHD (ADHD-DNs) exhibited impaired neurite outgrowth and branching, decreased mitochondrial mass in neurites, and abnormal intracellular ATP levels. In addition, BDNF mRNA was significantly decreased in ADHD-DNs. Supplementation with BDNF, however, significantly improved neurite development and mitochondrial function in ADHD-DNs. These results suggest that ADHD-DNs may have impaired neurite development and mitochondrial function associated with insufficient production of BDNF, which may be improved by exogenous BDNF supplementation. Findings such as these, from patient-derived SHED, may contribute to the future development of treatment strategies for aberrant dopaminergic signaling, mitochondrial functioning, and BDNF levels implicated in ADHD pathogenesis..
3. Yu Zhang, Hiroki Kato, Hiroshi Sato, Haruyoshi Yamaza, Yuta Hirofuji, Xu Han, Keiji Masuda, Kazuaki Nonaka, Folic acid-mediated mitochondrial activation for protection against oxidative stress in human dental pulp stem cells derived from deciduous teeth, Biochemical and biophysical research communications, 10.1016/j.bbrc.2018.11.169, 2019.01.
4. Xu Han, Kentaro Nonaka, Hiroki Kato, Haruyoshi Yamaza, Hiroshi Sato, Takashi Kifune, Yuta Hirofuji, Keiji Masuda, Osteoblastic differentiation improved by bezafibrate-induced mitochondrial biogenesis in deciduous tooth-derived pulp stem cells from a child with Leigh syndrome, Biochemistry and Biophysics Reports, 10.1016/j.bbrep.2018.11.003, 17, 32-37, 2019.03.
5. Huong Thi Nguyen Nguyen, Hiroki Kato, Keiji Masuda, Haruyoshi Yamaza, Yuta Hirofuji, Hiroshi Sato, Thanh Thi Mai Pham, Fumiko Takayama, Yasunari Sakai, Shoichi Ohga, Tomoaki Taguchi, Kazuaki Nonaka, Impaired neurite development associated with mitochondrial dysfunction in dopaminergic neurons differentiated from exfoliated deciduous tooth-derived pulp stem cells of children with autism spectrum disorder, Biochemistry and Biophysics Reports, 10.1016/j.bbrep.2018.09.004, 16, 24-31, 2018.12.
6. Thanh Thi Mai Pham, Hiroki Kato, Haruyoshi Yamaza, Keiji Masuda, Yuta Hirofuji, Hiroshi Sato, Huong Thi Nguyen Nguyen, Xu Han, Yu Zhang, Tomoaki Taguchi, Kazuaki Nonaka, Altered development of dopaminergic neurons differentiated from stem cells from human exfoliated deciduous teeth of a patient with Down syndrome, BMC Neurology, 10.1186/s12883-018-1140-2, 18, 1, 2018.08.
7. Saki Hirofuji, Yuta Hirofuji, Hiroki Kato, Keiji Masuda, Haruyoshi Yamaza, Hiroshi Sato, Fumiko Takayama, Michiko Torio, Yasunari Sakai, Shoichi Ohga, Tomoaki Taguchi, Kazuaki Nonaka, Mitochondrial dysfunction in dopaminergic neurons differentiated from exfoliated deciduous tooth-derived pulp stem cells of a child with Rett syndrome, Biochemical and Biophysical Research Communications, 10.1016/j.bbrc.2018.03.077, 498, 4, 898-904, 2018.04.
8. Yumiko I. Matsuishi, Hiroki Kato, Keiji Masuda, Haruyoshi Yamaza, Yuta Hirofuji, Hiroshi Sato, Hiroko Wada, Tamotsu Kiyoshima, Kazuaki Nonaka, Accelerated dentinogenesis by inhibiting the mitochondrial fission factor, dynamin related protein 1, Biochemical and Biophysical Research Communications, 10.1016/j.bbrc.2017.12.026, 495, 2, 1655-1660, 2018.01.
9. Hiroki Kato, Xu Han, Haruyoshi Yamaza, Keiji Masuda, Yuta Hirofuji, Hiroshi Sato, Thanh Thi Mai Pham, Tomoaki Taguchi, Kazuaki Nonaka, Direct effects of mitochondrial dysfunction on poor bone health in Leigh syndrome, Biochemical and Biophysical Research Communications, 10.1016/j.bbrc.2017.09.045, 493, 1, 207-212, 2017.11.
10. Hiroshi Sato, Hiroki Kato, Haruyoshi Yamaza, Keiji Masuda, Huong Thi Nguyen Nguyen, Thanh Thi Mai Pham, Xu Han, Yuta Hirofuji, Kazuaki Nonaka, Engineering of Systematic Elimination of a Targeted Chromosome in Human Cells, BioMed Research International, 10.1155/2017/6037159, 2017, 2017.01.
11. Hiroki Kato, Thanh Thi Mai Pham, Haruyoshi Yamaza, Keiji Masuda, Yuta Hirofuji, Xu Han, Hiroshi Sato, Tomoaki Taguchi, Kazuaki Nonaka, Mitochondria regulate the differentiation of stem cells from human exfoliated deciduous teeth, Cell Structure and Function, 10.1247/csf.17012, 42, 2, 105-116, 2017.05.
Presentations
1. Nguyen, H.T.N., Kato, H., Sato, H., Yamaza, H., Masuda, K. , Brain-derived neurotrophic factor improves neurite development and mitochondrial activity of dopaminergic neurons differentiated from exfoliated deciduous tooth-derived pulp stem cells of children with ADHD., Neuroscience 2019, 2019.10.
Membership in Academic Society
  • The Japanese Biochemical Society