胰岛素抑制糖基化终产物诱导心肌细胞炎症反应的研究

Effect of insulin on inflammation of myocyte of advanced glycation end-production

目的探讨糖基化终产物(AGEs)和胰岛素对乳鼠心肌细胞炎症反应的影响。方法原代培养乳鼠心肌细胞,分别用50mmol/L葡萄糖孵育的糖化白蛋白(AGE-BSA)、胰岛素(10-8mol/L)、糖化白蛋白加胰岛素干预24h,采用RT-PCR、免疫细胞化学染色、透射电镜法,观察AGE-BSA,胰岛素及AGE-BSA联合胰岛素对细胞PPAR-γmRNA和TNF-αmRNA表达、NF-κB活化以及细胞超微结构的影响。结果 AGE-BSA可诱导心肌细胞TNF-αmRNA表达及NF-κB活化,并可抑制PPAR-γmRNA表达,与对照组比较有显著差异(P<0.05)。胰岛素可抑制AGE-BSA诱导的TNF-αmRNA表达及NF-κB活化,并使PPAR-γmRNA表达上调,与AGE-BSA组比较有显著性差异(P<0.05)。AGE-BSA干预后的心肌细胞内内质网及线粒体增多,提示细胞发生非特异性炎症反应,而胰岛素可明显减轻AGE-BSA导致的病理改变。结论 AGE-BSA可通过诱导心肌细胞表达TNF-αmRNA及NF-κB活化,促使心肌细胞发生炎症反应,进而对心肌细胞造成损伤。胰岛素通过抑制TNF-αmRNA的表达并上调PPAR-γmRNA表达,可减轻AGE-BSA诱导的心肌细胞炎症反应,提示胰岛素在糖尿病心肌病的发病机制中具有重要的保护作用。

Objective To investigate the effects of advanced glycation end-production （AGE） and insulin on inflammation in cultured rat cardiomyocytes. Methods Primary eardiomyocytes were isolated from Sprague-Dawley neonatal （ 1 to 2 days old） rats ventricles. Neonatal rat ventricular myocytes were exposed to AGEs and insulin for 24 hours. PPARy mRNA and TNF-α mRNA expressions were determined by RT-PCR. Activation of NF-κB in the cells was examined by immunocytochemistry. The ultrastructure of the cells was detected by transmission electron microscope. Results The expression of TNF-α mRNA and the activation of NF-κB increased. The expression of PPARγmRNA decreased in AGE group compared with insulin and control group （P〈0. 05）. The differences among AGE and AGE＋ insulin groups were significant（P〈0. 05）. The numbers of chondriosome and smooth endoplasmic retieulum increased in AGE group. Conclusion AGE-BSA increases TNF-α mRNA expression and NF-κB avtivation, and restrains the expression of PPARy mRNA. Insulin enhanced the expression of PPARy mRNA and restrained the expression of TNF-αmRNA induced by AGE. These data suggest that insulin play an important role in the onset of diabetic cardiomyopathy.