蛋白激酶C抑制剂Ro-31-8220逆转高糖诱导乳鼠心肌细胞肥大的作用及其相关机制

Reverse effect of protein kinase C inhibitor Ro-31-8220 on the hypertrophy of cardiomyocytes of neonatal rats induced by high glucose levels

目的:观察蛋白激酶C(PKC)抑制剂Ro-31-8220对高糖诱导的乳鼠心肌细胞肥大的影响,并初步探讨PKC及其下游信号转导途径在其中的作用机制。方法:建立乳鼠心肌细胞培养模型,随机分成对照组(5.5mmol.L-1)、不同浓度高糖组(10mmol.L-1、15mmol.L-1、20mmol.L-1、25.5mmol.L-1)、高糖(25.5mmol.L-1)+PKC抑制剂Ro-31-8220组(50nmol.L-1)和高糖(25.5mmol.L-1)+NF-κB抑制剂BAY11-7082(5mmol.L-1)组,分别测定各组乳鼠心肌细胞直径和蛋白质含量,并应用Westernblotting检测乳鼠心肌细胞PKC-α、PKC-β2、p-PKC-α、p-PKC-β2、NF-κB和c-Fos等蛋白的表达水平。结果:高糖可以明显诱导乳鼠心肌细胞肥大,提高乳鼠心肌细胞PKC-α、PKC-β2、p-PKC-α、p-PKC-β2、NF-κB和c-Fos的蛋白表达,与对照组相比差异显著(P<0.01),并呈现一定的浓度依赖性;而Ro-31-8220能够逆转上述现象,其细胞直径和蛋白表达低于高糖组,并有显著差异(P<0.01)。结论:高糖能够浓度依赖性地诱导心肌细胞肥大,而PKC抑制剂Ro-31-8220则能抑制高糖所诱导的这种反应,其机制可能与PKC/NF-κB/c-Fos途径相关。

AIM： To study the effect of protein kinase C （PKC） inhibitor Ro- 31 -8220 on the hypertrophy of cardiomyocytes of neonatal rats induced by high glucose levels, and to investigate the role of PKC and its downstream signal transduction pathway. METHODS： Using cultured neonatal cardiac myecytes as a model, the cells were divided into： （1） control group （glucose 5. 5 mmol/L） ; （2） different high glucose level （10 mmol/L, 15 mmol/L, 20 mmol/L, 25. 5 mmol/L） ; （3） high glucose level （25.5 mmol/L） ＋ PKC inhibitor Ro -31 -8220 （50 mmol/L） ; （4） high glucose level （25.5mmol/L） ＋ NF - κB inhibitor （ BAY11 - 7082, 5 mmol/L）. The cellular diameters and protein level were measured and the expression of PKC -α, PKC - β2, p - PKC -α, p - PKC - β2, NF - κB and c - Fos were determined by Western blotting. RESULTS ： Neonatal cardiomyocytes cultured in high glucose concentration showed increased cellular diameters, protein level and higher expressions of PKC - α, PKC - β2, p - PKC - α, p - PKC - β2, NF - κB and c - Fos, which was consistent with the increased glucose levels and had statistical significance compared to control group （P 〈 0. 01 ）. PKC inhibitor Ro -31 -8220 reversed these changes induced by high glucose concentration as showed by decreased cellular diameters, protein level and expression of PKC - α, PKC - β2, P - PKC - α, p - PKC - β2, NF - κB and c- Fos, which had statistical significance compared to high glucose groups （P 〈 0. 01 ）. CONCLUSION： High glucose levels induce hypertrophy of cardiomyocytes. PKC inhibitor Ro -31 -8220 reverses the effect of high glucose on the cardiac myocytes, which may be via PKC/NF - κB/c - Fos pathway.