摘要
目的 :初步探讨胰淀素 (amylin)对人胰岛 β细胞凋亡的影响及其分子机制。 方法 :分离培养人胰岛细胞 ,免疫组化鉴定β细胞后分为对照组 (培养液中含 5 6mmol/L葡萄糖 )、胰淀素组 (培养液中含 10 μmol/L胰淀素+5 6mmol/L葡萄糖 )及氨基胍组 (培养液中含 10 μmol/L胰淀素 +0 5mmol/L氨基胍 +5 6mmol/L葡萄糖 ) ,于 37℃、5 %CO2 培养 2 4h后做胰岛素释放实验 ,测定培养液上清胰岛素、一氧化氮 (NO2 -/NO3 -)、还原型谷胱甘肽 (GSH)水平。原位末端核苷酸标记法 (TUNEL)和胰岛素免疫组化双染色法及ELISA检测胰岛β细胞凋亡 ,RT -PCR检测胰岛细胞p5 3和bcl- 2mRNA表达水平。结果 :胰淀素组胰岛 β细胞凋亡小体富计系数 (2 17± 0 2 1)、β细胞凋亡百分数 (13% )、NO2 -/NO3 -(2 0 1 3± 17 3) μmol/L和p5 3mRNA表达水平 (0 34± 0 0 4 )显著高于氨基胍组和对照组 (P <0 0 1) ,而胰岛素 (33 4± 13 1)mU·L-1/ 1× 10 6cells、GSH[(5 6± 0 8)mg/L]和bcl- 2mRNA(0 0 7± 0 0 1)表达水平则显著低于氨基胍组和对照组 (P <0 0 5 )。结论 :胰淀素可诱导人胰岛 β细胞凋亡 ,其机制可能与胰岛 β细胞抗氧化能力降低引起p5 3高表达有关。
AIM: To investigate the molecular mechanism of amylin in inducing apoptosis of human pancreatic islet β-cells. METHODS: Human pancreatic islet cells were isolated and cultured. The cells were treated with amylin or amylin and aminoguanidine (AG group) for 24 h, respectively. Apoptosis of pancreatic islet β-cells was studied by in situ TUNEL method combined with double staining for insulin and ELISA. The levels of insulin, NO 2 -/NO 3 - and glutathione (GSH), p53 mRNA and bcl-2 mRNA were also detected. RESULTS: (1) The enrichment factor and the apoptosis rate of pancreatic islet β-cells in amylin group were markedly higher than that in control group and AG group ( P <0 01). (2) The insulin level in amylin group was significantly lower than that in control group and AG group ( P <0 05). (3) The levels of NO 2 -/NO 3 - and p53 mRNA in amylin group were significantly higher than that in control group and AG group ( P <0 01), while the levels of GSH and bcl-2 mRNA were markedly decreased as compared with control group and AG group. CONCLUSIONS: Amylin increases apoptosis of human pancreatic islets β cells, resulting in decrease in insulin secretion. This may be due to increased expression of p53 and decreased expression of bcl-2 during the of oxidative stress induced by amylin.
出处
《中国病理生理杂志》
CAS
CSCD
北大核心
2005年第3期550-554,共5页
Chinese Journal of Pathophysiology
基金
浙江省卫生厅科研基金资助项目 (No .2 0 0 0A -0 36 )
关键词
胰淀素
胰岛
细胞凋亡
Amylin
Islets of Langerhans
Apoptosis
