TY - JOUR
T1 - Protective effect of hedgehog signaling on cytokine-induced cytotoxicity in pancreatic beta-cells
AU - Umeda, H.
AU - Ozaki, N.
AU - Mizutani, N.
AU - Fukuyama, T.
AU - Nagasaki, H.
AU - Arima, H.
AU - Oiso, Y.
PY - 2010
Y1 - 2010
N2 - Background: Hedgehog (Hh) signaling plays an important role in pancreas development. However, its role in the developed endocrine pancreas remains to be elucidated. To clarify whether Hh signaling participates in beta-cell survival, we investigated the role of Hh signaling in cytokine-induced apoptosis in pancreatic beta-cells. Methods: Insulin-producing INS-1E cells were transfected with Sonic Hh (Shh) expression vector or siRNA against Indian Hh (siIhh). The Hh signal inhibitor cyclopamine were pretreated in INS-1E cells and rat islets. The cells were exposed to 200U/ml IL-1β and 200U/ml IFN-γ for 48h. Apoptosis was estimated by flow cytometory and immunofluorescence staining for cleaved caspase-3. Nitric oxide generation was measured by Griess reaction. Results: We found that exposure to proinflammatory cytokines increased Ihh expression in rat islets and INS-1E cells. Overexpression of Shh reduced cytokine-induced apoptosis. By contrast, treatment with cyclopamine increased cytokine-induced apoptosis in INS-1E cells and rat islets. Treatment with the siIhh showed same results in INS-1E cells. Forced expression of Shh suppressed cytokine-induced nuclear factor-B promoter activity, leading to attenuation of nitric oxide synthase 2 expression and nitric oxide production, while Ihh knockdown enhanced this pathway in INS-1E cells. Conclusion: Our findings suggest that Hh signaling is implicated in protecting beta-cells from cytokine-induced cytotoxicity.
AB - Background: Hedgehog (Hh) signaling plays an important role in pancreas development. However, its role in the developed endocrine pancreas remains to be elucidated. To clarify whether Hh signaling participates in beta-cell survival, we investigated the role of Hh signaling in cytokine-induced apoptosis in pancreatic beta-cells. Methods: Insulin-producing INS-1E cells were transfected with Sonic Hh (Shh) expression vector or siRNA against Indian Hh (siIhh). The Hh signal inhibitor cyclopamine were pretreated in INS-1E cells and rat islets. The cells were exposed to 200U/ml IL-1β and 200U/ml IFN-γ for 48h. Apoptosis was estimated by flow cytometory and immunofluorescence staining for cleaved caspase-3. Nitric oxide generation was measured by Griess reaction. Results: We found that exposure to proinflammatory cytokines increased Ihh expression in rat islets and INS-1E cells. Overexpression of Shh reduced cytokine-induced apoptosis. By contrast, treatment with cyclopamine increased cytokine-induced apoptosis in INS-1E cells and rat islets. Treatment with the siIhh showed same results in INS-1E cells. Forced expression of Shh suppressed cytokine-induced nuclear factor-B promoter activity, leading to attenuation of nitric oxide synthase 2 expression and nitric oxide production, while Ihh knockdown enhanced this pathway in INS-1E cells. Conclusion: Our findings suggest that Hh signaling is implicated in protecting beta-cells from cytokine-induced cytotoxicity.
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U2 - 10.1055/s-0030-1254151
DO - 10.1055/s-0030-1254151
M3 - Article
C2 - 20533175
AN - SCOPUS:78349263139
SN - 0947-7349
VL - 118
SP - 692
EP - 698
JO - Experimental and Clinical Endocrinology and Diabetes
JF - Experimental and Clinical Endocrinology and Diabetes
IS - 10
ER -