Synergistic inhibition of tumor necrosis factor-related apoptosis-inducing ligand-induced apoptosis in human pancreatic β cells by Bcl-2 and X-linked inhibitor of apoptosis
- 作者：Ou ; Dawei ; Wang ; Xiaojie ; Metzger ; Daniel L. ; James ; Roger F.L. ; Pozzilli ; Paolo ; Plesner ; Annette ; et. al.
- 关键词：type 1 diabetes ; β ; -cell apoptosis ; Bcl-2 ; XIAP ; TRAIL
- 刊名：Human Immunology
- 出版年：2005
- 期刊代码：75_01988859
- 类别：bio
- 出版时间：March, 2005
- 卷：66
- 期：3
- 页码：274-284
- 文件大小：377 K
摘要
To better understand the cytokine death-signal transduction pathways in human β cells, we investigated the inhibitory effects of Bcl-2 (protooncogene bcl-2) and X-linked inhibitor of apoptosis (XIAP) on TRAIL (TNF-related apoptosis-inducing ligand)-induced human β-cell destruction. A panel of Bcl-2-overexpressing transfectants of the human β-cell lines NES2Y and CM was developed by transfection with a pEFpGKpuro vector containing Bcl-2 or an empty vector as a control. TRAIL-induced cytotoxicity and apoptosis of Bcl-2-overexpressing β cells were clearly decreased, in comparison with wild-type cells and the empty vector transfectants. XIAP-overexpressing CM, NES2Y, and primary islet cells were generated by exposing cells to recombinant adenovirus-expressing XIAP (AdXIAP) or AdLacz as a control. TRAIL-induced cytotoxicity and apoptosis of CM, NES2Y, and primary islet cells infected with AdXIAP were clearly reduced compared with controls. Interestingly, cytotoxicity induced by TRAIL in human β cells transfected with both Bcl-2 and AdXIAP was much less than that observed in human β cells transfected with either Bcl-2 or XIAP alone (p < 0.005 in CM and p < 0.03 in NES2Y). Overexpression of both Bcl-2 and XIAP inhibited TRAIL-induced activation of caspases as well as TRAIL-mediated damage of mitochondrial function in cells, suggesting possible regulatory mechanisms. These results indicate that Bcl-2 and XIAP synergistically inhibit TRAIL-mediated death pathways in human β cells.