突触融合蛋白1A和突触小体相关蛋白-25在逆转α细胞高糖毒性中的作用  

The role of syntaxinlA/synaptosome-associated protein-25 in reversing hyperglycemia-induced a cell toxicity

作　　者：沈晓霞[1] 李宏亮[1] 洪靖[1] 校娟[1] 潘琳[2] 李光伟[1] 

机构地区：[1]卫生部中日友好医院内分泌代谢病中心,北京100029 [2]卫生部中日友好医院临床医学研究所细胞生物室,北京100029

出　　处：《中华医学杂志》2009年第12期851-854,共4页National Medical Journal of China

摘　　要：目的探讨逆转高糖毒性对α细胞胰高糖素分泌和合成的影响以及可能的机制。方法在小鼠转基因胰高糖素瘤细胞株（TC1-6）细胞（Ot细胞株）分别给予5．5mmol／L（低糖组）和25mmol／L（高糖组）葡萄糖的培养基培养10d，25mmol／L葡萄糖培养5d／5．5mmol／L葡萄糖培养5d（高糖／低糖组）以及5．5mmol／L葡萄糖培养5d／25mmol／L葡萄糖培养5d（低糖／高糖组），检测各组细胞胰高糖素分泌及其mRNA的表达；Western印迹检测持续高糖以及恢复血糖正常后TC1-6细胞突触融合蛋白1A蛋白和突触小体相关蛋白-25（SNAP-25）的表达水平。结果（1）高糖／低糖组TC1-6细胞胰高糖素比高糖组分泌下降29％[（2．68±0．21）ng／mg比（3．74±2．99）ng／mg，P〈0．05]；（2）高糖／低糖组TC1-6细胞比高糖组胰高糖素mRNA表达下降（52．6±2．8）％（P〈0．05）；（3）高糖组TC1-6细胞表达突触融合蛋白1A和SNAP-25的水平较低糖组表达分别升高36％和69％（P〈0．05），而高糖／低糖组突触融合蛋白1A和SNAP-25蛋白表达与高糖组相比明显下调，分别下降49％和56％（P〈0．05）。结论解除高糖毒性，α细胞胰高糖素分泌异常明显改善，促进胰高糖素分泌相关的突触融合蛋白1A和SNAP-25蛋白表达相应降低。Objective To investigate the effects of reversal of hyperglycemic toxicity on the synthesis and secretion of glucagon by the α cells and the possible mechanisms thereof. Methods Mouse glucagonoma cells of the line TC1-6 were cultured in medium containing 5.5 mmol/L glucose for 10 days （ low glucose group, LG）, in medium containing 25 mmol/L glucose for 10 days （ high glucose group, HG） , in medium with 25 mmol/L glucose for 5 days and then in medium with 5.5 mmol/L glucose for 5 days （high-low glucose group, HL group）, or in medium with 5.5 mmol/L glucose for 5 days and then in medium with 25 mmol/L glucose for 5 days （LH group）, Radioimmunoassay was used to detect the glucagon concentration in the supernatant. RT-PCR was used to detect the mRNA expression of glucagon in the TCl- 6 cells. Western blotting was used to detect the protein expression of the Snare proteins： syntaxinlA and synaptosome-associated protein （ SNAP）-25. Results （ 1 ） The glucagon level of the HG/LG group was lower than that of the HG group by 29% （P 〈0. 05）. （2） The glucagon mRNA expression level in the TCl- 6 cells of the HG/HL group was significantly lower than that of the HG group by （52. 6 ± 2. 8 ） % （ P 〈 0. 05）. （3） The syntaxinlA and SNAP-25 expression levels in the TC1-6 cells of the HG group were significantly higher than those of the LG group by 36% and 69% respectively （both P 〈 0. 05）, and the syntaxinlA and SNAP-25 expression levels in the TC1-6 cells of the HG/LG group were significantly lower than those of the HG group by 49% and 56% respectively （ both P 〈 0. 05）. Conclusion After removing the high glucose toxicity the abnormal glucagon secretion by the α-cells can be ameliorated obviously, and the expression levels of syntaxinl A and SNAP-25 proteins that promote the secretion of glucagon are reduced accordingly.

关 键 词：胰岛Α细胞 胰高血糖素 逆转高糖毒性 

分 类 号：R686[医药卫生—骨科学]