The pathogenic role of cystathionine ?-lyase/hydrogen sulfide in streptozotocin-induced diabetes in mice.
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ABSTRACT: Reduced ?-cell mass and increased activities of ATP-sensitive K(+) channels in pancreatic ? cells are associated with the pathogenesis of diabetes. Cystathionine ?-lyase (CSE) is a major hydrogen sulfide (H(2)S)-producing enzyme in pancreatic ? cells. Herein, we examine the effects of genetic and pharmacologic ablation of CSE on ?-cell functions and their correlation with streptozotocin (STZ)-induced diabetes. Compared with wild-type mice, CSE knockout (CSE KO) mice that received STZ injections exhibited a delayed onset of diabetic status. The application of dl-propargylglycine (PPG) to inhibit CSE activity protected wild-type mice from STZ-induced hyperglycemia and hypoinsulinemia. STZ significantly increased pancreatic H(2)S production in wild-type mice but not in CSE KO mice. STZ induced more apoptotic ?-cell death in wild-type mice than in CSE KO mice. STZ exposure decreased the viability of cultured INS-1E cells, which was partly reversed by PPG co-treatment. STZ also significantly stimulated H(2)S production in cultured INS-1E cells. In addition, STZ stimulated ATP-sensitive K(+) currents in pancreatic ? cells from wild-type mice but not in the presence of PPG or in ? cells from CSE KO mice. Sodium hydrosulfide injection instantly increased blood glucose, decreased plasma insulin, and deteriorated glucose tolerance in mice. Take together, these results provide evidence that the CSE/H(2)S system plays a critical role in regulating ?-cell functions.
SUBMITTER: Yang G
PROVIDER: S-EPMC3157274 | biostudies-literature | 2011 Aug
REPOSITORIES: biostudies-literature
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