|Last modified date：2023.11.28
Associate Professor / Bioscience and Biotechnology / Faculty of Agriculture
|Last modified date：2023.11.28
|Juneha Bak, Yoshiyuki Miyazaki, Hayato Nakano, Toshiro Matsui, Profiling sulfate content of polysaccharides in seaweed species using a ligand-assisted 1H-NMR assay, Food Science and Technology Research, 10.3136/fstr.27.505, 27, 3, 505-510, 2021.05.
|Juneha BAK, Yoshiyuki MIYAZAKI, Hayato NAKANO, Toshiro MATSUI, Ligand-aided 1H Nuclear Magnetic Resonance Spectroscopy for Non-destructive Estimation of Sulfate Content in Sulfated Saccharides, Analytical Sciences, 10.2116/analsci.20P163, 36, 10, 1269-1274, 2020.10.
|Yoshiyuki Miyazaki, Yuri Iwaihara, Juneha Bak, Hayato Nakano, Shugo Takeuchi, Hideaki Takeuchi, Toshiro Matsui, Daisuke Tachikawa, The cooperative induction of macrophage activation by fucoidan derived from Cladosiphon okamuranus and β-glucan derived from Saccharomyces cerevisiae, Biochemical and Biophysical Research Communications, 10.1016/j.bbrc.2019.06.010, 516, 1, 245-250, 2019.08, The present study investigated immune stimulatory effects of Cladosiphon okamuranus-derived fucoidan to activate murine macrophage-like cell line RAW264, and the functional relationship with zymosan, a Saccharomyces cerevisiae-derived β-glucan. The production of nitric oxide (NO) and tumor necrosis factor-α (TNF-α) in RAW264 cells were remarkably enhanced in the presence of 10 μg/mL fucoidan, and the stimulatory effects of fucoidan were maximally augmented in combinational treatment with 500 ng/mL zymosan, whereas any TLR ligands had no those effects. Confocal microscopic analyses suggested that fucoidan bound on plasma membrane, and it was estimated that some cell surface molecules acted as receptor for fucoidan because cytochalasin D, an inhibitor of phagocytosis, did not affect the immune enhancing activities, whereas methyl-β-cyclodextrin (MβCD), a general agent for disruption of lipid rafts, diminished that. Furthermore, it was revealed that the additive effects of zymosan on the immune activation with fucoidan was thought to be mediated by dectin-1 based on the results with dectin-1-knockdown RAW264 cells. All of results suggested that fucoidan and some kinds of β-glucan would cooperatively reinforce the activity of innate immune cells via interactive receptor crosstalk..
|Histamine release by granulocytes is a critical event in the induction of type I allergy. We investigated the effects of four different fruit vinegars made from yama-budo, haskap, blueberry and pomegranate on histamine release by the basophilic leukemia cell line RBL-2H3. Results clearly indicated that these fruit vinegars, especially pomegranate vinegar, have potent inhibitory effects on histamine release. We then performed adsorption chromatography with Diaion HP20 to estimate the bioactive components in pomegranate vinegar; the fraction eluted by 50% ethanol (EtOH) showed the most potent suppressive effect. Next, we subjected the 50% EtOH-fraction to liquid-liquid division with ethyl acetate (AcOEt), and suppressive activity was observed in both the water and AcOEt layer fractions, indicating the existence of multiple bioactive components. Furthermore, suppression of histamine release by each fraction was almost completely abolished by treatment with polyphenol adsorbent polyvinylpolypyrrolidone. These results suggested that the pomegranate vinegar contains multiple polyphenol compounds involved in the suppression of histamine release by granulocytes..
|We studied the nutritional components and functional activities of 6 parts (flower bud, stem, lower main stalk, leaf stalk, leaf, root) of raw whole broccoli (Brassica oleracea var. Italica). Flower buds showed the highest levels of vitamin C (188.2mg/100g) and S-methylmethionine (16.7mg/100g). The buds contained 64.9mg/100g of polyphenols. Moreover, they exhibited the highest histamine release inhibitory activity. The vitamin C, S-methylmethionine and polyphenol contents of the leaves were 18%, 29% and 3.1 times those of flower buds, respectively. The leaves showed histamine release inhibitory activity and leukotriene release inhibitory activity. Additionally, the leaves tended to decrease IgE production. The leaves also showed anti-allergic activity as compared with flower buds. The vitamin C, S-methylmethionine and polyphenol contents of the roots were 13%, 25% and 83% of those of flower buds, respectively. Notably, aqueous extracts of roots produced the highest proliferative arrest in MCF-7 human breast cancer cells. These results suggest that useful components exist not only in the edible flower buds but in all parts of broccoli..
|Mika Takai, Yoshiyuki Miyazaki, Hirofumi Tachibana, Koji Yamada, The enhancing effect of fucoidan derived from Undaria pinnatifida on immunoglobulin production by mouse spleen lymphocytes, Bioscience, Biotechnology, and Biochemistry, 10.1080/09168451.2014.930323, 78, 10, 1743-1747, 2014.10, In this study, we revealed that a Mekabu (Udaria pinnantifida) extract enhanced immunoglobulin (Ig) production of mouse spleen lymphocytes. Furthermore, it was suggested that water-soluble and high molecular weight ingredients in the Mekabu extract have significant enhancing effect on Ig production. Therefore, fucoidan was estimated as the active component..
|Shinsuke Yasukawa, Yoshiyuki Miyazaki, Chika Yoshii, Mako Nakaya, Naoko Ozaki, Shuji Toda, Etsushi Kuroda, Ken Ichi Ishibashi, Tomoharu Yasuda, Yohei Natsuaki, Fumika Mi-Ichi, Eíichi Iizasa, Takeshi Nakahara, Masanori Yamazaki, Kenji Kabashima, Yoichiro Iwakura, Toshiyuki Takai, Takashi Saito, Tomohiro Kurosaki, Bernard Malissen, Naohito Ohno, Masutaka Furue, Hiroki Yoshida, Hiromitsu Hara, An ITAM-Syk-CARD9 signalling axis triggers contact hypersensitivity by stimulating il-1 production in dendritic cells, Nature communications, 10.1038/ncomms4755, 5, 2014.05, A variety of reactive organic compounds, called haptens, can cause allergic contact dermatitis. However, the innate immune mechanisms by which haptens stimulate dendritic cells (DCs) to sensitize T cells remain unclear. Here we show that the coupling of ITAM-Syk-CARD9 signalling to interleukin-1 (IL-1) secretion in DCs is crucial for allergic sensitization to haptens. Both MyD88 and Caspase recruitment domain-containing protein 9 (CARD9) signalling are required for contact hypersensitivity (CHS). Naïve T cells require signals received through IL-1R1-MyD88 for effector differentiation, whereas DCs require CARD9 and spleen tyrosine kinase (Syk) signalling for hapten-induced IL-1Î± /Î 2 secretion and their ability to prime T cells. DC-specific deletion of CARD9, DAP12, Syk or NLRP3, but not MyD88, is sufficient to abolish CHS. All tested haptens, but not irritants, can induce Syk activation, leading to both the CARD9/BCL10-dependent pro-IL-1 synthesis (signal1) and reactive oxygen species-mediated NLRP3 inflammasome activation (signal2), required for IL-1 secretion. These data unveil an innate immune mechanism crucial for allergic contact sensitization to chemical compounds..
|Tetsuaki Hirase, Hiromitsu Hara, Yoshiyuki Miyazaki, Noriko Ide, Ai Nishimoto-Hazuku, Hirokazu Fujimoto, Christiaan J M Saris, Hiroki Yoshida, Koichi Node, Interleukin 27 inhibits atherosclerosis via immunoregulation of macrophages in mice, American Journal of Physiology - Heart and Circulatory Physiology, 10.1152/ajpheart.00198.2013, 305, 3, 2013.08, Chronic inflammation in arterial wall that is driven by immune cells and cytokines plays pivotal roles in the development of atherosclerosis. Interleukin 27 (IL-27) is a member of the IL-12 family of cytokines that consists of IL-27p28 and Epstein-Barr virus induced gene 3 (EBI3) and has anti-inflammatory properties that regulate T cell polarization and cytokine production. IL-27-deficient (Ldlr-/Ebi3-/-) and IL-27 receptor-deficient (Ldlr-/-WSX-1-/-) Ldlr-/- mice were generated and fed with a high-cholesterol diet to induce atherosclerosis. Roles of bone marrow-derived cells in vivo and macrophages in vitro were studied using bone marrow reconstitution by transplantation and cultured peritoneal macrophages, respectively. We demonstrate that mice lacking IL-27 or IL-27 receptor are more susceptible to atherosclerosis compared with wild type due to enhanced accumulation and activation of macrophages in arterial walls. The number of circulating proinflammatory Ly6Chi monocytes showed no significant difference between wild-type mice and mice lacking IL-27 or IL-27 receptor. Administration of IL-27 suppressed the development of atherosclerosis in vivo and macrophage activation in vitro that was indicated by increased uptake of modified low-density lipoprotein and augmented production of proinflammatory cytokines. These findings define a novel inhibitory role for IL-27 in atherosclerosis that regulates macrophage activation in mice..
|Kanako Murayama, Tomoko Sawa, Hiroaki Koga, Satoshi Yamaguchi, Motofumi Kumazoe, Takafumi Otsuka, Yoshiyuki Miyazaki, Hirofumi Tachibana, Koji Yamada, Anti-cancer effect of water extracts prepared from chrysanthemum flowers and leaves shiranui himekiku, Nippon Shokuhin Kagaku Kogaku Kaishi, 10.3136/nskkk.60.80, 60, 2, 80-86, 2013.05, The flower of the chrysanthemum plant Shiranui Himekiku has been used as a folk medicine for a variety of diseases including cancer, and cytotoxic effects in some cancer lines have been reported. However, little is known about the anti-cancer activity of the leaf extract and its active compounds. Therefore, to clarify the anti-cancer activity of Shiranui Himekiku leaf and flower, the anti-proliferative effects of the extracts on human cancer cells were examined. Both leaf and flower water extracts dose-dependently suppressed the proliferation of the human breast cancer cell line MCF-7 at concentrations >25 μg/ml. Furthermore, the anti-proliferative effect in MCF-7 is more than four times that in normal human dermal fibroblast cells. When heated at 100- for 30 minutes, the proliferation inhibitory activity of the flower extract was unchanged. In contrast, under identical conditions, the activity of the leaf extract was lost. The extracts were separated into two fractions; one with a molecular weight (MW) >10 000 (high molecular weight fraction) (HMW) and the other with a MW>10 000 (low molecular weight fraction) (LMW). A significant proliferation inhibitory effect can be seen in the LMW fraction of both extracts, but the HMW fraction of the leaf extract also slightly inhibits cell growth. Both polyphenols and non-polyphenols are candidate active compounds because the anti-cancer effect was seen in the polyphenol-and non-polyphenol-fractions. These results suggest that the extracts contain several types of anti-cancer components and that both leaves and flowers can be useful..
|Koji Yamada, Tomoko Sawa, Kanako Murayama, Satoshi Yamaguchi, Yoshiyuki Miyazaki, Hirofumi Tachibana, Histamine release-suppressive effect of water extracts prepared from flower and leaf of chrysanthemum, Shiranui himekiku, Nippon Shokuhin Kagaku Kogaku Kaishi, 10.3136/nskkk.59.394, 59, 8, 394-400, 2012.10, To clarify the immunoregulatory activity of the chrysanthemum plant Shiranui himekiku, the effects of its flower and leaf extracts on proliferation and histamine release of rat and human basophilic leukemia cells were examined. Water extracts of flower and leaf suppressed proliferation and histamine release of rat RBL-2H3 cells dose-dependently at concentrations over 10μg/mL. The histamine release-suppressive effect of the leaf extract was as strong as that of the flower extract. The effects of these extracts on proliferation and histamine release of human KU812 cells were much weaker than those on RBL-2H3 cells. When these extracts were heated at 100°C for 30 min, the histamine release-inhibitory activity was unchanged, but the proliferation-inhibitory activity decreased slightly. Histamine release-inhibitory activity was detected in water extract of a commercial dried flower extract prepared with a stainless kettle as well as that prepared with an earthen pot as recommended by the manufacturer. These results suggest that these extracts contain anti-allergic components, that leaves are useful as well as flowers, and that the extracts can be prepared using stainless pots, which are useful in IH cooking..
|Hirokazu Fujimoto, Tetsuaki Hirase, Yoshiyuki Miyazaki, Hiromitsu Hara, Noriko Ide-Iwata, Ai Nishimoto-Hazuku, Christiaan J.M. Saris, Hiroki Yoshida, Koichi Node, IL-27 inhibits hyperglycemia and pancreatic islet inflammation induced by streptozotocin in mice, American Journal of Pathology, 10.1016/j.ajpath.2011.08.001, 179, 5, 2327-2336, 2011.11, Inflammation driven by immune cells and pro-inflammatory cytokines is implicated in pancreatic β-cell injury, leading to the development of diabetes mellitus. IL-27, a cytokine consisting of IL-27p28 and Epstein-Barr virusinduced gene 3 (EBI3), binds a membrane-bound heterodimeric receptor consisting of the IL-27 receptor α chain (WSX-1) and gp130. IL-27 has anti-inflammatory properties that regulate T-cell polarization and cytokine production. We evaluated blood glucose and islet proinsulin concentrations, inflammatory cell infiltration in islets, and expression of IL-1β mRNA in pancreas in wild-type (WT), EBI3 -/-, and WSX-1 -/- mice treated with streptozotocin (STZ). Hyperglycemia was augmented in EBI3 -/- and WSX-1 -/- mice compared with WT mice. Islet proinsulin levels after STZ treatment were lower in EBI3 -/- and WSX-1 -/- mice than in WT mice. The infiltration of islets by F4/80 +CD11c -7/4 - macrophages, CD4 + T cells, and CD8 + T cells was increased in EBI3 -/- and WSX-1 -/- mice compared with WT mice. The administration of recombinant IL-27, compared with control, decreased the blood glucose level, immune cell infiltration into islets, and IL-1β mRNA expression in the pancreas and increased islet proinsulin levels in WT and EBI3 -/- mice. Thus, IL-27 inhibits STZ-induced hyperglycemia and pancreatic islet inflammation in mice and represents a potential novel therapeutic approach for β-cell protection in diabetes..
|Yoshiyuki Miyazaki, Shinjiro Hamano, Seng Wang, Yohei Shimanoe, Yoichiro Iwakura, Hiroki Yoshida, IL-17 is necessary for host protection against acute-phase Trypanosoma cruzi infection, Journal of Immunology, 10.4049/jimmunol.0900047, 185, 2, 1150-1157, 2010.07, IL-17A is a key cytokine that induces inflammatory responses through the organized production of inflammatory cytokines, such as IL-6, TNF-α, and GM-CSF, and induces neutrophil migration. The roles of IL-17A in infection of intracellular protozoan parasites have not been elucidated, although augmented immune responses by IL-17A are important for the resolution of some bacterial and fungal infections. Therefore, we experimentally infected IL-17A-deficient (IL-17A-/-) mice with Trypanosoma cruzi. IL-17A-/- mice had a lower survival rate and prolonged worse parasitemia compared with control C57BL/6 wild-type (WT) mice postinfection. In the infected IL-17A-/- mice, multiple organ failure was observed compared with WT mice, as reflected by the marked increase in serologic markers of tissue injury, such as aspartate aminotransferase, which resulted in increased mortality of IL-17A-/- mice. Expression of cytokines, such as IFN-γ, IL-6, and TNF-α, was lower in liver-infiltrating cells from the IL-17A-/- mice compared with WT mice. A similar defect was observed in the expression of neutrophil enzymes, such as myeloperoxidase and lipoxygenase, whereas cellular infiltration into the infected tissues was not affected by IL-17A deficiency. These results suggested that the efficient activation of immune-related cells critical for the killing of T. cruzi was impaired in the absence of IL-17A, resulting in the greater susceptibility of those mice to T. cruzi infection. From these results, we conclude that IL-17A is important for the resolution of T. cruzi infection..
|Honglian Tong, Yoshiyuki Miyazaki, Masanori Yamazaki, Hiromitsu Hara, Herman Waldmann, Shohei Hori, Hiroki Yoshida, Exacerbation of delayed-type hypersensitivity responses in EBV-induced gene-3 (EBI-3)-deficient mice, Immunology Letters, 10.1016/j.imlet.2010.01.001, 128, 2, 108-115, 2010.02, Epstein-Barr virus-induced gene-3 (EBI-3) associates with p28 to form interleukin-27 (IL-27) or with IL-12p35 to form IL-35. Both IL-27 and IL-35 have immunosuppressive functions and especially IL-35 has been implicated in the suppressive function of regulatory T cells (Treg). To address the role of EBI-3 in immune regulation, delayed-type hypersensitivity (DTH) responses were examined in EBI-3-deficient (EBI-3-/-) mice. EBI-3-/- mice developed deteriorated DTH responses as shown by the enhanced footpad swelling and augmented infiltration of inflammatory cells into the antigen-challenged footpads as compared with wild-type (WT) mice. While EBI-3-deficiency showed little effects on antigen-specific IFN-γ production of lymph node cells, IL-17 production was drastically augmented in EBI-3-/- cells as compared with in WT cells. In addition, reduced IL-10 production was also evident in EBI-3-/- CD4+ T cells. Interestingly, the development and suppressive function of Treg to inhibit effector T cell proliferation was not affected by EBI-3-deficiency. These data clearly demonstrated the immunosuppressive function of EBI-3 and provided complementary evidence that EBI-3 and EBI-3-containing cytokines might be taken into consideration as potential targets for some immune-related diseases..
|Hiroki Yoshida, Mako Nakaya, Yoshiyuki Miyazaki, Interleukin 27
A double-edged sword for offense and defense, Journal of Leukocyte Biology, 10.1189/jlb.0609445, 86, 6, 1295-1303, 2009.12, Cytokine-mediated immunity plays a crucial role in the pathogenesis of various diseases including infection and autoimmune diseases. IL-27, along with IL-12, -23, and -35, belongs to the IL-12 cytokine family. These family members play roles in regulation of Th cell differentiation. IL-27 is unique in that although it induces Th1 differentiation, the same cytokine suppresses immune responses. In the absence of IL-27-mediated immunosuppression, hyperproduction of various proinflammatory cytokines concomitant with severe inflammation is observed. The immunosuppressive effects of IL-27 depend on IL-2 suppression, inhibition of Th17 development, and induction of IL-10 production. Administration of IL-27 suppresses some diseases of autoimmune or allergic origin, demonstrating its potential in therapy of diseases mediated by inflammatory cytokines. In this review, we discuss recent studies about the role of IL-27 in immune regulation in view of its pro- and antiinflammatory properties and possible therapeutic application..
|Yukari Shinozaki, Sen Wang, Yoshiyuki Miyazaki, Kohji Miyazaki, Hisakata Yamada, Yasunobu Yoshikai, Hiromitsu Hara, Hiroki Yoshida, Tumor-specific cytotoxic T cell generation and dendritic cell function are differentially regulated by interleukin 27 during development of anti-tumor immunity, International Journal of Cancer, 10.1002/ijc.24107, 124, 6, 1372-1378, 2009.03, Interleukin (IL-) 27 is a member of IL-12 cytokine family with Th1-promoting and anti-inflammatory effects, IL-27 has been shown to facilitate tumor-specific cytotoxic T lymphocyte (CTL) induction against various tumors. However, IL-27 suppresses cytokine production of lymphocytes and antigen-presenting function of dendritic cells (DCs). To examine the in vivo role of IL-27 in generation of anti-tumor immunity, we examined IL-27-mediated antitnmor-effects using WSX-1 (IL-27 receptor α chain)-deficient (WSX-1
) mice. In WSX-1
mice inoculated with B16 melanoma cells, tumor growth was higher than in wild-type (WT) mice. Accordingly, tumor-specific CTL generation was lower in WSX-1
mice than in WT mice. CTL induction in WSX-1
mice was not restored by transfer of WT DCs pulsed with TRP2 peptide, indicating that IL-27 is directly required for generation of tumor-speeiic CTLs. However, when transferred into tumor-bearing mice, WSX-1
DCs pulsed with TRP2 peptide was more potent than WT DCs in tumor growth inhibition and generation of CTLs, indicating suppressive effects of IL-27 on DC function. Finally, the combination of WT CD8
T cells and KO DCs is more potent in generation of antigen-specific CTLs than any other combinations. Expression of perforin gene and percentages of tumor-specific CD8
T cells were also the highest in the combination of WT CD8
T cells and WSX-1
DCs, It was thus revealed that IL-27 promotes CTL generation while suppressing DC function during generation of tumor immunity. The combination of WT T cells and IL-27 signal-defective DCs may have therapeutic potential against tumors..
|Yohei Shimanoe, Yoshiyuki Miyazaki, Hiromitsu Hara, Akira Inokuchi, Hiroki Yoshida, Amelioration of experimental allergic rhinitis with suppression of topical immune responses by lack of IL-27/WSX-1 signaling, Annals of Allergy, Asthma and Immunology, 10.1016/S1081-1206(10)60085-3, 102, 3, 223-232, 2009.01, BackgroundAllergic rhinitis is 1 of the most common atopic diseases with strong similarity to asthma. Interleukin (IL) 27 is an immunosuppressive cytokine, and lack of the IL-27 receptor (WSX-1) resulted in exacerbation of allergic airway hyperresponsiveness. Objective: To address the role of IL-27/WSX-1 in the rhinitis model compared with the asthma model. Methods: Wild-type or WSX-1 / female mice were immunized intraperitoneally 4 times with ovalbumin adsorbed to aluminum potassium sulfate at a 1-week interval. The sensitized mice were then challenged for 14 days with ovalbumin intranasally from days 22 to 35. Clinical scores, serum antigen specific IgE levels, and cytokine production in the nasal lavage fluid were examined. Cytokine and chemokine expression in the cervical lymph nodes, nasopharynx-associated lymphoid tissues, and nasal mucosa was also examined. Results: WSX-1/ mice developed augmented immune responses in the serum (IgE production), cervical lymph nodes (cytokine and chemokine expression), and nasopharynx-associated lymphoid tissues (cytokine and chemokine expression), whereas local responses, such as clinical scores and nasal lavage fluid cytokine production, were reduced in WSX-1/ mice. Expression of some chemokines was also reduced in the nasal mucosal tissues of WSX-1 / mice. Conclusion: In contrast to the immunosuppressive role observed in the asthma model, IL-27 WSX-1 topically plays an exacerbating role in the pathogenesis of allergic rhinitis, presumably through differential expression of chemokines..
|Hiroki Yoshida, Yoshiyuki Miyazaki, Regulation of immune responses by interleukin-27 (Immunological Reviews (2008) 226, (234-247)), Immunological Reviews, 10.1111/j.1600-065X.2008.00738.x, 227, 1, 2009.01.
|Hiroki Yoshida, Yoshiyuki Miyazaki, Regulation of immune responses by interleukin-27, Immunological Reviews, 10.1111/j.1600-065X.2008.00710.x, 226, 1, 234-247, 2008.12, Cytokine-mediated immunity plays a crucial role in the pathogenesis of various diseases including autoimmunity. Recently, interleukin-27 (IL-27) was identified, which, along with IL-12, IL-23, and IL-35, belongs to the IL-12 cytokine family. These family members play roles in the regulation of T helper (Th) cell differentiation. IL-27 is unique in that while it induces Th1 differentiation, the same cytokine suppresses immune responses. In the absence of IL-27-mediated immunosuppression, hyper-production of various pro-inflammatory cytokines concomitant with severe inflammation in affected organs was observed in IL-27 receptor α chain (WSX-1)-deficient mice infected with Trypanosoma cruzi. Experimental allergic or inflammatory responses were also enhanced in WSX-1-deficient mice. The immunosuppressive effects of IL-27 depend on inhibition of the development of Th17 cells (a newly identified inflammatory T-helper population) and induction of IL-10 production. Moreover, administration of IL-27 or augmentation of IL-27 signaling suppresses some diseases of autoimmune or allergic origin, demonstrating its potential in therapy of diseases mediated by inflammatory cytokines. In this review, we discuss recent studies on the role of IL-27 in immunity to parasitic and bacterial infections as well as in allergy and autoimmunity in view of its pro- and anti-inflammatory properties..
|Yoshiyuki Miyazaki, Yohei Shimanoe, Seng Wang, Hiroki Yoshida, Amelioration of delayed-type hypersensitivity responses by IL-27 administration, Biochemical and Biophysical Research Communications, 10.1016/j.bbrc.2008.06.038, 373, 3, 397-402, 2008.08, Interleukin (IL-) 27 is a member of the IL-12 cytokine family. Although recent analyses of WSX-1 (IL-27 receptor α chain)-deficient mice as well as in vitro studies using recombinant IL-27 revealed the immunosuppressive function of IL-27, in vivo role and therapeutic potential of IL-27 remain poorly elucidated. Here we investigated the effect of IL-27 administration on delayed-type hypersensitivity (DTH). While WSX-1-deficient mice showed higher DTH responses as shown by the degree of footpad swelling, administration of IL-27 significantly ameliorated the footpad swelling. Since the activation status of the draining lymph node cells were not affected by IL-27 deficiency, it was suggested that IL-27 affected the effector phase of the response. These results collectively indicate that IL-27 has a suppressive effect on activated T cells in the experimental model and also has a therapeutic potential for some diseases caused by immune disorder..
|Hiroki Yoshida, Yoshiyuki Miyazaki, Interleukin 27 signaling pathways in regulation of immune and autoimmune responses, International Journal of Biochemistry and Cell Biology, 10.1016/j.biocel.2008.05.020, 40, 11, 2379-2383, 2008.06, Cytokine-mediated immunity plays a crucial role in pathogenesis of various diseases including autoimmune disease. Recently, interleukin 27 was identified, which along with interleukin 23 belongs to the interleukin 12 cytokine family. Interleukin 27 is pivotal for the induction of T helper 1 responses. Recent studies, however, revealed that interleukin 27 has an immunosuppressive property. In interleukin 27 receptor-deficient mice, various pro-inflammatory cytokines were over produced resulting in excess of immune responses. The immunosuppressive effects of interleukin 27 depend on suppression of interleukin 2 production, inhibition of the development of T helper 17 cells (a newly identified inflammatogenic T helper population), and induction of interleukin 10 production. Activation of signal transducers and activators of transcription 1 and 3 is critical in the immunosuppressive function of interleukin 27. Interleukin 27 suppresses some diseases of autoimmune or allergic origin, demonstrating its promising potential in therapy of diseases mediated by inflammatory cytokines..
|Takeru Yoshimura, Kohei Sonoda, Yoshiyuki Miyazaki, Yoichiro Iwakura, Tatsuro Ishibashi, Akihiko Yoshimura, Hiroki Yoshida, Differential roles for IFN-γ and IL-17 in experimental autoimmune uveoretinitis, International Immunology, 10.1093/intimm/dxm135, 20, 2, 209-214, 2008.02, IL-17-producing CD4+ T cells, so called Th17 cells, constitute a newly identified inflammatogenic cell population, which is critically involved in some inflammatory diseases. To explore the role of Th17 cells in murine experimental autoimmune uveoretinitis (EAU), a model of human autoimmune uveitis where Th1 responses predominantly participate in the pathogenesis, IL-17- mice were immunized with interphotoreceptor retinoid-binding protein peptide 1-20 for disease induction. Funduscopic examination revealed that EAU was induced in IL-17- mice just like in wild-type (WT) mice at early phases of the disease. However, at later/maintenance phases, the severity was significantly reduced in IL-17- mice. Expression of IFN-γ and MCP-1 was comparable between WT and IL-17- mice during the time course. In vivo blockade of IFN-γ and IL-4 resulted in exacerbation of EAU at later phases with augmented IL-17 production. Taken together, our data demonstrated that IL-17/Th17 participates in the late phases of EAU and also that Th1 and Th17 responses are differentially required for EAU..
|Sen Wang, Yoshiyuki Miyazaki, Yukari Shinozaki, Hiroki Yoshida, Augmentation of antigen-presenting and Th1-promoting functions of dendritic cells by WSX-1(IL-27R) deficiency, Journal of Immunology, 10.4049/jimmunol.179.10.6421, 179, 10, 6421-6428, 2007.11, WSX-1 is the α subunit of the IL-27R complex expressed by T, B, NK/NKT cells, as well as macrophages and dendritic cells (DCs). Although it has been shown that IL-27 has both stimulatory and inhibitory effects on T cells, little is known on the role of IL-27/WSX-1 on DCs. LPS stimulation of splenic DCs in vivo resulted in prolonged CD80/CD86 expression on WSX-1-deficient DCs over wild-type DCs. Upon LPS stimulation in vitro, WSX-1-deficient DCs expressed Th1-promoting molecules higher than wild-type DCs. In an allogeneic MLR assay, WSX-1-deficient DCs were more potent than wild-type DCs in the induction of proliferation of and IFN-γ production by responder cell proliferation. When cocultured with purified NK cells, WSX-1-deficient DCs induced higher IFN-γ production and killing activity of NK cells than wild-type DCs. As such, Ag-pulsed WSX-1-deficient DCs induced Th1-biased strong immune responses over wild-type DCs when transferred in vivo. WSX-1-deficient DCs were hyperreactive to LPS stimulation as compared with wild-type DCs by cytokine production. IL-27 suppressed LPS-induced CD80/86 expression and cytokine production by DCs in vitro. Thus, our study demonstrated that IL-27/WSX-1 signaling potently down-regulates APC function and Th1-promoting function of DCs to modulate overall immune responses..
|Hiroki Yoshida, Yoshiyuki Miyazaki, Sen Wang, Shinjiro Hamano, Regulation of defense responses against protozoan infection by interleukin-27 and related cytokines, Journal of Biomedicine and Biotechnology, 10.1155/2007/79401, 2007, 2007.07, Cytokine-mediated immunity is crucial in the defense against pathogens.Recently, IL-23 and IL-27 were identified, which along with IL-12 belong to the IL-12 cytokine family. IL-27 is pivotal for the induction of helper T cell (Th) 1 responses while IL-23 is important for the proliferation of memory type Th1 cells. Recent studies revealed that IL-27 also has an anti-inflammatory property. In some protozoan infection, various proinflammatory cytokines were over produced causing lethal inflammatory responses in IL-27 receptor-deficient mice. The anti-inflammatory effect of IL-27 depends, at least partly, on inhibition of the development of Th17cells, a newly identified Th population that is induced by IL-23 and is characterized by the production of the inflammatogenic cytokine, IL-17.IL-27 thus has a double identity as an initiator and as an attenuator of immune responses and inflammation. With the discoveries of the new IL-12-related cytokines and Th17 cells, Th development is facing a new paradigm..
|Takeru Yoshimura, Atsunobu Takeda, Shinjiro Hamano, Yoshiyuki Miyazaki, Ichiko Kinjyo, Tatsuro Ishibashi, Akihiko Yoshimura, Hiroki Yoshida, Two-sided roles of IL-27
Induction of Th1 differentiation on naive CD4+ T cells versus suppression of proinflammatory cytokine production including IL-23-induced IL-17 on activated CD4+ T cells partially through STAT3-dependent mechanism, Journal of Immunology, 10.4049/jimmunol.177.8.5377, 177, 8, 5377-5385, 2006.10, Recent lines of evidence have demonstrated that IL-27, a newly identified IL-12-related cytokine, has two apparently conflicting roles in immune responses: one as an initiator of Th1 responses and the other as an attenuator of inflammatory cytokine production. Although the BL-27-mediated Th1 initiation mechanism has been elucidated, little is known about the molecular basis for the suppression of cytokine production. In the present study, we demonstrated that IL-27 suppressed the production of various proinflammatory cytokines by fully activated CD4+ T cells while it had no effect on the cytokine production by CD4+ T cells at early phases of activation. IL-27 also suppressed IL-17 production by activated CD4+ T cells, thereby counteracting IL-23, another IL-12-related cytokine with proinflammatory effects. In fully activated CD4+ T cells, STAT3 was preferentially activated by IL-27 stimulation, whereas both STAT1 and 3 were activated by IL-27 in early activated CD4+ T cells. Lack of STAT3 in fully activated cells impaired the suppressive effects of IL-27. These data indicated that the preferential activation of STAT3 in fully activated CD4+ T cells plays an important role in the cytokine suppression by IL-27/WSX-1..
|Woong Kyung Suh, Seng Wang, Gordon S. Duncan, Yoshiyuki Miyazaki, Elizabeth Cates, Tina Walker, Beata U. Gajewska, Elissa Deenick, Wojciech Dawicki, Hitoshi Okada, Andrew Wakeham, Annick Itie, Tania H. Watts, Pamela S. Ohashi, Manel Jordana, Hiroki Yoshida, Tak W. Mak, Generation and characterization of B7-H4/B7S1/B7x-deficient mice, Molecular and Cellular Biology, 10.1128/MCB.00755-06, 26, 17, 6403-6411, 2006.09, Members of the B7 family of cosignaling molecules regulate T-cell proliferation and effector functions by engaging cognate receptors on T cells. In vitro and in vivo blockade experiments indicated that B7-H4 (also known as B7S1 or B7x) inhibits proliferation, cytokine production, and cytotoxicity of T cells. B7-H4 binds to an unknown receptor(s) that is expressed on activated T cells. However, whether B7-H4 plays nonredundant immune regulatory roles in vivo has not been tested. We generated B7-H4-deficient mice to investigate the roles of B7-H4 during various immune reactions. Consistent with its inhibitory function in vitro, B7-H4-deficient mice mounted mildly augmented T-helper 1 (Th1) responses and displayed slightly lowered parasite burdens upon Leishmania major infection compared to the wild-type mice. However, the lack of B7-H4 did not affect hypersensitive inflammatory responses in the airway or skin that are induced by either Th1 or Th2 cells. Likewise, B7-H4-deficient mice developed normal cytotoxic T-lymphocyte reactions against viral infection. Thus, B7-H4 plays a negative regulatory role in vivo but the impact of B7-H4 deficiency is minimal. These results suggest that B7-H4 is one of multiple negative cosignaling molecules that collectively provide a fine-tuning mechanism for T-cell-mediated immune responses..
|Sakiko Shimizu, Naonobu Sugiyama, Kohsuke Masutani, Atsushi Sadanaga, Yoshiyuki Miyazaki, Yasushi Inoue, Mitsuteru Akahoshi, Ritsuko Katafuchi, Hideki Hirakata, Mine Harada, Shinjiro Hamano, Hitoshi Nakashima, Hiroki Yoshida, Membranous glomerulonephritis development with Th2-type immune deviations in MRL/lpr mice deficient for IL-27 receptor (WSX-1), Journal of Immunology, 10.4049/jimmunol.175.11.7185, 175, 11, 7185-7192, 2005.12, MKL/lpr mice develop spontaneous glomerulonephritis that is essentially identical with diffuse proliferative glomerulonephritis (World Health Organization class IV) in human lupus nephritis, Lupus nephritis is one of the most serious complications of systemic lupus erythematosus. Diffuse proliferative glomerulonephritis is associated with autoimmune responses dominated by Th1 cells producing high levels of IFN-γ. The initial mounting of Th1 responses depends on the function of the WSX-1 gene, which encodes a subunit of the IL-27R with homology to IL-12R. In mice deficient for the WSX-1 gene, proper Th1 differentiation was impaired and abnormal Th2 skewing was observed during infection with some intracellular pathogens. Disruption of the WSX-1 gene dramatically changed the pathophysiology of glomerulonephritis developing in MRL/lpr mice, WSX-1-/- MRL/lpr mice developed disease resembling human membranous glomerulonephritis (World Health Organization class V) with a predominance of IgG1 in glomerular deposits, accompanied by increased IgG1 and IgE in the sera. T cells in WSX-1 -/- MKL/lpr mice displayed significantly reduced IFN-γ production along with elevated IL-4 expression. Loss of WSX-1 thus favors Th2-type autoimmune responses, suggesting that the Th1/Th2 balance may be a pivotal determinant of human lupus nephritis development..
|Yoshiyuki Miyazaki, Hiromasa Inoue, Mikiko Matsumura, Koichiro Matsumoto, Takako Nakano, Miyuki Tsuda, Shinjiro Hamano, Akihiko Yoshimura, Hiroki Yoshida, Exacerbation of experimental allergic asthma by augmented Th2 responses in WSX-1-deficient mice, Journal of Immunology, 10.4049/jimmunol.175.4.2401, 175, 4, 2401-2407, 2005.08, WSX-1 (IL-27R) is a class I cytokine receptor with homology to gp130 and IL-12 receptors and is typically expressed on CD4+ T lymphocytes. Although previous reports have clarified that IL-27/WSX-1 signaling plays critical roles in both Th1 differentiation and attenuation of cell activation and proinflammatory cytokine production during some bacterial or protozoan infections, little is known about the importance of WSX-1 in cytokine-mediated diseases of allergic origin. To this aim, we took advantage of WSX-1-deficient (WSX-1-/-) mice and induced experimental asthma, in which Th2 cytokines are central modulators of the pathology. OVA-challenged WSX-1 -/- mice showed marked enhancement of airway responsiveness with goblet cell hyperplasia, pulmonary eosinophil infiltration, and increased serum IgE levels compared with wild-type mice. Production of Th2 cytokines, which are largely responsible for the pathogenesis of asthma, was augmented in the lung or in the culture supernatants of peribronchial lymph node CD4+ T cells from WSX-1-/- mice compared with those from wild-type mice. Surprisingly, IFN-γ production was also enhanced in WSX-1-/- mice, albeit at a low concentration. The cytokine overproduction, thus, seems independent from the Th1-promoting property of WSX-1. These results demonstrated that IL-27/WSX-1 also plays an important role in the down-regulation of airway hyper-reactivity and lung inflammation during the development of allergic asthma through its suppressive effect on cytokine production..
|Atsushi Yamanaka, Shinjiro Hamano, Yoshiyuki Miyazaki, Kazunari Ishii, Atsunobu Takeda, Tak W. Mak, Kunisuke Himeno, Akihiko Yoshimura, Hiroki Yoshida, Hyperproduction of Proinflammatory Cytokines by WSX-1-Deficient NKT Cells in Concanavalin A-Induced Hepatitis, Journal of Immunology, 10.4049/jimmunol.172.6.3590, 172, 6, 3590-3596, 2004.03, Administration of Con A induces liver injury that is considered to be an experimental model for human autoimmune or viral hepatitis, where immunopathology plays roles mediated by activated lymphocytes, especially NK1.1+ CD3+ NKT cells, and inflammatory cytokines, including IFN-γ and IL-4. In the present study we investigated the role of WSX-1, a component of IL-27R, in Con A-induced hepatitis by taking advantage of WSX-1 knockout mice. WSX-1-deficient mice were more susceptible to Con A treatment than wild-type mice, showing serum alanine aminotransferase elevation and massive necrosis in the liver. Although the development of NKT cells appeared normal in WSX-1 knockout mice, purified NKT cells from the knockout mice produced more IFN-γ and IL-4 than those from wild-type mice in response to stimulation with Con A both in vitro and in vivo. In addition, hyperproduction of proinflammatory cytokines, including IL-1, IL-6, and TNF-α, was observed in the knockout mice after Con A administration. These data revealed a novel role for WSX-1 as an inhibitory regulator of cytokine production and inflammation in Con A-induced hepatitis..
|Mako Nakaya, Masao Yamasaki, Yoshiyuki Miyazaki, Hirofumi Tachibana, Koji Yamada, Estrogenic compounds suppressed interferon-gamma production in mouse splenocytes through direct cell-cell interaction, In Vitro Cellular and Developmental Biology - Animal, 39, 8-9, 383-387, 2003.09, Here, we reported the effects of 17β-estradiol (E2), isoflavone genistein (Gen), and daidzein (Dai) on the production of interferon (IFN)-γ by splenocytes isolated from C57BL/6N mice. When mouse splenocytes were stimulated with lipopolysaccharide, E2, Gen, and Dai suppressed the production of IFN-γ. However, when only nonadherent cell populations of splenocytes were tested, none of these estrogenic compounds suppressed IFN-γ production. This result indicates that IFN-γ production by nonadherent cell populations of splenocytes treated with estrogens is regulated by adherent cell populations. Moreover, direct cell-cell interaction between both populations was necessary for suppression of IFN-γ production by nonadherent populations. In addition, E2 conjugated with bovine serum albumin inhibited IFN-γ production as well as E2. This result suggests that the plasma membrane-associated estrogen receptor plays a prominent role in this suppression mechanism..
|Shinjiro Hamano, Kunisuke Himeno, Yoshiyuki Miyazaki, Kazunari Ishii, Atsushi Yamanaka, Atsunobu Takeda, Manxin Zhang, Hajime Hisaeda, Tak W. Mak, Akihiko Yoshimura, Hiroki Yoshida, WSX-1 is required for resistance to Trypanosoma cruzi infection by regulation of proinflammatory cytokine production, Immunity, 10.1016/S1074-7613(03)00298-X, 19, 5, 657-667, 2003.01, WSX-1 is a class I cytokine receptor with homology to the IL-12 receptors and is essential for resistance to Leishmania major infection. In the present study, we demonstrated that WSX-1 was also required for resistance to Trypanosoma cruzi. WSX-1-/- mice exhibited prolonged parasitemia, severe liver injury, and increased mortality over wild-type mice. WSX-1 -/- splenocytes produced enhanced levels of Th2 cytokines, which were responsible for the prolonged parasitemia. Massive necroinflammatory lesions were observed in the liver of infected WSX-1-/- mice, and IFN-γ that was overproduced in WSX-1-/- mice compared with wild-type mice was responsible for the lesions. In addition, vast amounts of various proinflammatory cytokines, including IL-6 and TNF-α, were produced by liver mononuclear cells in WSX-1-/- mice. Thus, during T. cruzi infection, WSX-1 suppresses liver injury by regulating production of proinflammatory cytokines, while controlling parasitemia by suppression of Th2 responses, demonstrating its novel role as an inhibitory regulator of cytokine production..
|Yoshiyuki Miyazaki, Hirofumi Tachibana, Koji Yamada, Inhibitory effect of peroxisome proliferator-activated receptor-γ ligands on the expression of IgE heavy chain germline transcripts in the human B cell line DND39, Biochemical and Biophysical Research Communications, 10.1016/S0006-291X(02)00709-X, 295, 2, 547-552, 2002.07, The expression of ε germline transcripts (εGT) induced by interleukin (IL)-4 stimulation is essential for the progression of IgE-directed class switching. In this study, we examined the effects of various ligands for their ability to bind to the peroxisome proliferator-activated receptors (PPARs) and to modify the IL-4-induced εGT expression in the human B cell line DND39. We show here that the PPARγ ligand, 15-deoxy-Δ12;14-prostaglandin J2 (15d-PGJ2), can suppress εGT expression at 1 μM without inhibiting cell proliferation. A synthetic and PPARγ-specific ligand, ciglitazone, also suppressed εGT expression in a dose-dependent manner at concentrations between 10 and 50μM. Agonists for other PPAR isoforms did not affect εGT expression at concentrations between 0.01 and 10μM. We also demonstrated that 1μM 15d-PGJ2 was able to suppress the IL-4-induced phosphorylation of the Signal Transducer and Activator of Transcription 6 (STAT6), which is a transcription factor essential for εGT expression. Therefore, the suppression of STAT6 phosphorylation by 15d-PGJ2 is thought to participate in the inhibition of εGT expression. These results suggest that PPARγ ligands inhibit IL-4-induced IgE class switching in B lymphocytes..
|Yoshiyuki Miyazaki, M. Noguchi, Hirofumi Tachibana, K. Yamada, Polyunsaturated fatty acids are not essential for survival and proliferation of a human B cell line , In Vitro Cellular and Developmental Biology - Animal, 10.1290/1071-2690(2001)0372.0.CO;2, 37, 7, 399-401, 2001.10.
|Yoshiyuki Miyazaki, Masao Yamasaki, Hiroko Mishima, Keiko Mansho, Hirofumi Tachibana, Koji Yamada, Oxidative stress by visible light irradiation suppresses immunoglobulin production in mouse spleen lymphocytes, Bioscience, Biotechnology and Biochemistry, 10.1271/bbb.65.593, 65, 3, 593-598, 2001.03, In this study, we attempted to induce the oxidative stress in mouse spleen lymphocytes with visible light irradiation and examined the effects of lipid peroxidation on immunoglobulin (Ig) production. The spleen lymphocytes were isolated from 8-week-old male balb/c mice and irradiated with 300 W visible light. When the cells were cultured for 72 hr, Ig contents in culture supernatants were decreased gradually by irradiation for over 30 min. The cell viability was also lowered by the irradiation. Intracellular phosphatidylcholine hydroperoxide (PCOOH) levels and thiobarbituric acid-reactive substances (TBARS) values in culture supernatants were measured as indices of lipid peroxidation and we found that Ig production by mouse spleen lymphocytes was suppressed accompanied with the progress of peroxidation of intracellular phospholipids. Cell membrane fluidity was also significantly decreased, but the intracellular Ig level was not changed in the irradiated cells. These results suggest that the peroxidation of intracellular lipids is a cause of the suppression of Ig production by mouse spleen lymphocytes via lowering cell viability and suppressing Ig synthesis and secretion..
|Yoshiyuki Miyazaki, Y. Tokunaga, K. Takagaki, S. Tsusaki, Hirofumi Tachibana, K. Yamada, Effect of dietary cabbage fermentation extract and young barley leaf powder on immune function of Sprague-Dawley rats, Journal of Nutritional Science and Vitaminology, 10.3177/jnsv.47.253, 47, 3, 253-257, 2001.01, We investigated dietary effects of cabbage fermentation extract (CFE) and young barley leaf powder (YBLP) on rat immune functions, Male Sprague-Dawley rats of 4 wk age were fed for 3 wk diets containing these samples at 0.1 or 1% level. After the feeding period, serum IgG level was significantly higher in the rats fed 1% CFE. IgG productivity of spleen lymphocytes was enhanced dose-dependently in both groups of CFE and YBLP. Furthermore, IgG productivity of mesenteric lymph node (MLN) lymphocytes was approximately 2 times higher in the rats fed 1% CFE diet than in the control ones. IgA productivity of MLN lymphocytes tended to increase in both of CFE and YBLP groups. From these results, it was suggested that dietary CFE and YBLP reinforced Ig productivity in both systemic and intestinal immune systems. Moreover, CFE feeding tended to enhance the production of TNF-α by spleen lymphocytes. In spleen phospholipids, the level of arachidonic acid, a substrate for inflammatory lipid mediators, was not affected by CFE or YBLP feeding..
|Masao Yamasaki, Atsushi Ikeda, Akira Hirao, Yoko Tanaka, Yoshiyuki Miyazaki, Tatsuya Rikimaru, Mitsuo Shimada, Keizo Sugimachi, Hirofumi Tachibana, Koji Yamada, Effect of dietary conjugated linoleic acid on the in vivo growth of rat hepatoma dRLh-84, Nutrition and Cancer, 10.1207/S15327914NC402_10, 40, 2, 140-148, 2001.01, We examined the effect of dietary conjugated linoleic acid (CLA) on the growth of injected hepatoma dRLh-84 in Donryu rats. After experimental diets containing 0% or 2% CLA were given to male Donryu rats for 3 wk, dRLh-84 cells were injected into the left lobe of the hepatic capsule, and the experimental diet was continued. The cells formed a solid tumor ≥1 wk after the injection, and thereafter the tumor grew with feeding duration. In a morphological study, this tumor appeared to be a low-differentiated hepatoma, and there was no remarkable difference in the morphology of the tumor between 0% and 2% CLA groups. Tumor weight was significantly higher in the 2% CLA group than in the 0% CLA group throughout the feeding period after the injection. Serum glutamic-oxaloacetic transaminase and glutamic-pyruvic transaminase activities were significantly higher in 2% CLA-injected rats than in 0% CLA-injected rats at 3 wk after the injection. CLA upregulated acyl-CoA oxidase activity, especially 1 wk after the injection. However, dietary CLA did not activate carnitine palmitoyl transferase II, which is a rate-limiting enzyme in the mitochondrial β-oxidation pathway. Natural killer cell activity in the spleen tended to be higher in injected rats, but a significant effect of dietary CLA was not recognized. Serum interferon-γ and tumor necrosis factor-α levels were higher in injected than in sham rats. More-over, these levels were higher in 2% CLA groups than in the respective 0% CLA groups..
|Dal Ho Han, Yoshiyuki Miyazaki, Hirofumi Tachibana, Koji Yamada, Optimization of estrogenic activity detection method using human breast cancer MCF-7 cells, Journal of the Faculty of Agriculture, Kyushu University, 44, 3-4, 339-348, 2000.02, We tried to optimize the assay system using human breast cancer MCF-7 cells for detection of estrogenic activity of environmental estrogens. Since fetal bovine serum (FBS) contains various growth factors including estrogen, 100 ml of FBS was treated with 5 g of activated charcoal to remove estrogen. MCF-7 cells were cultured with RPMI 1640 medium supplemented with FBS or charcoal-treated FBS (cFBS), in the presence of 17β-estradiol or flavonoids. Then, the cells were trypsinized and cell number was counted using a Coulter Counter. When the cells were cultured in the medium containing 0 to 5% FBS, proliferation-stimulating activity of daidzein and genistein was detected most strongly in the medium containing 1% FBS. In the case cFBS-supplemented medium, the effect of flavonoids was detectable, in all cFBS concentrations. The proliferation-stimulating effect of daidzein and genistein was detectable after a 72-hr lag period. In the presence of 1% FBS or 1% cFBS, 17 β -estradiol enhanced proliferation of the cells at the concentrations between 10-11 and 10-8M, while daidzein and genistein enhanced it only at 10-8M. On the other hand, quercetin and luteolin exerted a proliferation-inhibiting activity against MCF-7 cells at the concentrations over 10-11M. These results indicate that estrogenic activity of flavonoids against MCF-7 cells was detectable in the medium supplemented with 1% FBS or 1 to 5% cFBS. Proliferation-inhibitory activity of quercetin and luteolin suggests that these compounds exert anti-estrogenic and anti-cancer activities..
|Yuichiro Kuramoto, Yoshiyuki Miyazaki, Shinichiro Inoue, Hirotaka Haruta, Hirofumi Tachibana, Michihiro Sugano, Koji Yamada, Effect of Rose Bengal on Immunoglobulin Production by Mouse B Lymphoma, WEHI-279 Cells, Journal of Agricultural and Food Chemistry, 10.1021/jf9804793, 46, 12, 5368-5372, 1998.01, The effect of Rose Bengal (RB) on immunoglobulin (Ig) production by mouse B lymphoma WEHI-279 cells was examined. At 100 μM, RB increased IgE concentration in the culture medium but decreased the levels of IgG and IgM. To examine whether RB affects to the secretion of IgE from WEHI-279 cells or its synthesis, intracellular, and extracellular Ig levels were compared. The cytoplasmic IgE level in the cells treated with 100 μM RB was higher than in the cells cultured without RB. Reverse transcriptase-polymerase chain reaction (RT-PCR) experiment showed that the level of productive ∈ transcripts of the RB-added group was higher than that of the control but RB did not affect the germ-line ∈ transcripts. These results suggested that RB enhancement of IgE was due to the increase of the Ig synthesis by WEHI-279 cells and not to the increase of secretion activity of Ig from the cells nor to the enhancement of class-switching to IgE producing cells..