Wu LiJun, Zhao LianYou, Zheng QiangSun, Shang FuJun, Wang XianMei, Wang LiFeng, Lang Bing
Institute Hypertension, Department of Cardiology, TangDu Hospital, Fourth Military Medical University, Xi'an 710038, PR China.
Mol Cell Biochem. 2006 Mar;284(1-2):65-71. doi: 10.1007/s11010-005-9014-5. Epub 2006 Mar 14.
Cardiotrophin-1 (CT-1) is a cytokine involved in the growth and survival of cardiac cells via activation of the Janus activated kinase/signal transducer activator of transcription (JAK/STAT). Statins, 3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, have effects that extend beyond cholesterol reduction and inhibit vascular smooth muscle cell (VSMC) proliferation and cardiac hypertrophy. However, whether stains also can inhibitin vitromyocardial hypertrophy or not still remains elusive. The purpose of this study was to explore the effects of simvastatin on the hypertrophy of cultured rat cardiomyocytes induced by CT-1 and to investigate whether this effect was mediated via JAK-STAT signaling pathway.
Primary cardiomyocytes from 2-day-old (P2) rats were cultured, stimulated with CT-1, and treated with various concentration of simvastatin. Incorporation of [(3)H] leucine, reverse transcription-polymerase chain reaction and western blotting techniques were used to investigate cardiacmyocyte size, ANP mRNA and JAK-STAT protein expression. Simvastatin was proved, in a dose-independent manner, to decrease cardiacmyocytes size as well as protein synthesis, and inhibit ANP mRNA synthesis and JAK-STAT protein expression induced by CT-1 in cardiacmyocytes.
These results suggest that simvastatin can ameliorate cardiacmyocytes hypertrophyin vitrovia JAK-STAT signaling pathways. The present study provides a novel understanding and alternative therapeutic strategy for cardiac hypertrophy.
心肌营养素-1(CT-1)是一种细胞因子,通过激活Janus激活激酶/信号转导子和转录激活子(JAK/STAT)参与心脏细胞的生长和存活。他汀类药物,即3-羟基-3-甲基戊二酰辅酶A(HMG-CoA)还原酶抑制剂,其作用不仅限于降低胆固醇,还可抑制血管平滑肌细胞(VSMC)增殖和心肌肥大。然而,他汀类药物是否也能抑制体外心肌肥大仍不清楚。本研究的目的是探讨辛伐他汀对CT-1诱导的培养大鼠心肌细胞肥大的影响,并研究这种作用是否通过JAK-STAT信号通路介导。
培养2日龄(P2)大鼠的原代心肌细胞,用CT-1刺激,并用不同浓度的辛伐他汀处理。采用[(3)H]亮氨酸掺入、逆转录-聚合酶链反应和蛋白质印迹技术研究心肌细胞大小、心房钠尿肽(ANP)mRNA和JAK-STAT蛋白表达。结果证明,辛伐他汀以剂量非依赖性方式减小心肌细胞大小以及蛋白质合成,并抑制CT-1诱导的心肌细胞中ANP mRNA合成和JAK-STAT蛋白表达。
这些结果表明,辛伐他汀可通过JAK-STAT信号通路改善体外心肌细胞肥大。本研究为心肌肥大提供了新的认识和替代治疗策略。