胰岛素抑制糖基化终产物诱导心肌细胞炎症反应的研究

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。

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

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.