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目的:观察高糖毒性对大鼠胰岛细胞系INS-1细胞中血红素氧合酶1蛋白表达的损害作用,并研究信号分子刺激下细胞损伤的自我保护机制。方法:分别采用不同葡萄糖浓度孵育或葡萄糖代谢物葡萄糖胺持续孵育培养INS-1细胞,造成高糖毒性损伤,进而采用胰岛素以及核转录因子Nrf2激动剂莱芜硫烷刺激细胞保护信号机制改善损伤,蛋白印迹法检测细胞中血红素氧合酶1的表达情况。结果:高浓度葡萄糖溶液中(25 mM)孵育INS-1细胞48小时,血红素氧合酶1的表达水平较正常情况显著下降(P<0.05)。高浓度葡萄糖与葡萄糖胺共刺激对实验细胞中血红素氧合酶1的表达下调具有协同作用。胰岛素对实验细胞中血红素氧合酶1表达具有上调作用,但上调作用强度随培养环境中葡萄糖浓度的增高而降低。核转录因子Nrf2激动剂莱芜硫烷孵育处理实验细胞后,胞内血红素氧合酶1表达水平在葡萄糖胺刺激下上调,且与培养环境中葡萄糖浓度水平无关(P<0.05)。结论:高糖毒性可损害胰岛β细胞内抗氧化酶-血红素氧合酶1的表达,而胰岛素可激活下游通路尤其是Nrf2信号通路,对抗高糖诱导的氧化应激损伤,从而保护胰岛细胞。
OBJECTIVE: To observe the effect of high glucose on the expression of hemeoxygenase-1 in pancreatic islet cell line INS-1 and to study the mechanism of self-protection of cell injury induced by signal molecules. Methods: INS-1 cells were incubated with different glucose concentrations or glucose metabolites, and glucose oxidase was incubated in INS-1 cells. The insulin and nuclear factor K Western blotting was used to detect the expression of heme oxygenase 1 in the cells. Results: Compared with the normal condition, the expression of heme oxygenase 1 in INS-1 cells incubated with 25 mM glucose for 48 hours decreased significantly (P <0.05). Co-stimulation with high glucose and glucosamine has a synergistic effect on the down-regulation of heme oxygenase-1 in experimental cells. Insulin up-regulated the expression of heme oxygenase-1 in experimental cells, but the intensity of up-regulation decreased with the increase of glucose concentration in culture environment. The intracellular expression of heme oxygenase 1 was up-regulated under the stimulation of glucosamine, and had no correlation with the glucose concentration in the culture environment (P <0.05) after incubation with nuclear factor Nrf2 and Laiwu Sulfane. CONCLUSION: High glucose toxicity can impair the expression of the antioxidant enzyme-heme oxygenase-1 in pancreatic β-cells. Insulin activates the downstream pathway, especially the Nrf2 signaling pathway, to protect against islet cells against high glucose-induced oxidative stress injury .