AT1-R-JAK／STAT 信号通路对肥大心肌细胞表达内脂素的调节

目的：观察心肌细胞肥大过程中应用不同的信号通道阻断剂阻断AngⅡ作用后内脂素的表达情况，研究内脂素水平变化的意义。方法采用SD乳鼠（出生2～3 d），利用差速贴壁法提取原代心肌细胞并进行培养，48 h后改为无血清的培养基继续培养，24 h后分组。分别应用不同的信号通道阻断剂阻断AngⅡ的干预作用。应用RT-PCR、Western-Blot技术检测心肌细胞中内脂素表达情况，应用Western-Blot技术检测心肌细胞脑氨钠素（ BNP）表达情况。结果心肌细胞活力（光密度值）和BNP表达水平在AngⅡ浓度为10－8、10－7、10－6 mol／L时逐渐升高，AngⅡ浓度为10－6 mol／L时达峰值，而AngⅡ浓度升高为10－5 mol／L时心肌细胞活力下降，BNP表达水平下降。内脂素和内脂素mRNA水平，在AngⅡ浓度为10－8、10－7、10－6 mol／L时呈逐渐升高趋势， AngⅡ浓度为10－5 mol／L时达峰值。在AngⅡ浓度为10－6 mo1／L时，心肌细胞活力、内脂素mRNA表达和内脂素蛋白表达与对照组比较，差异均有统计学意义（ P ＜0．05）。心肌细胞MTT产物（ OD值）、内脂素mRNA和蛋白表达、BNP蛋白表达水平，随时间延长而增加。PD123319预干预组和AngⅡ干预组内脂素mRNA和蛋白表达水平明显高于对照组和替米沙坦预干预组（P＜0．05）。AngⅡ组内脂素mRNA和蛋白表达水平与对照组、AG490＋AngⅡ组、SP600125＋AngⅡ组和U0126＋AngⅡ组比较，差异有统计学意义（ P ＜0．05），AG490＋AngⅡ组、SP600125＋AngⅡ组和U0126＋AngⅡ组明显高于对照组（P＜0．05）。结论在AngⅡ诱导的心肌细胞肥大中内脂素表达的增加，由AT1-R-JAK／STAT信号通路所介导。

The regulation effects of AT1-R-JAK/STAT signal pathway on expressions of visfatin in hypertrophy myocardial cells ;in vitro

Objective To observe the expressions of visfatin in angiotensin Ⅱ( AngⅡ)-induced cardiomyocyte hypertrophy in vitro after blocked by different signal channel blockers,and to explore the significance of changes of visfatin levels.Methods The primary generation cardiomyocytes from Sprague-Dawley (SD) neonate rats (2~3d age) were cultured in vitro with routine medium,however, which were cultured in medium without serum after 48 hours.The cardiomyocytes were divided into different groups after 24 hours,and the intervention effects of AngⅡ were blocked by different signal channel blockers.The expression levels of visfatin in cardiomyocytes were detected by RT-PCR,Western-Blot,respectively,moreover, the expression levels of brain natriuretic peptide (BNP) in cardiomyocytes were detected by Western-Blot.Results The activity of cardiomyocytes (optical density value,OD) and expression levels of BNP were gradually increased when AngⅡconcentration at 10 -8 ,10 -7 ,10 -6 mol/L.The activity of cardiomyocytes and expression levels of BNP were decreased when AngⅡconcentration at 10 -5 mol/L.The levels of visfatin and visfatin mRNA were increased when AngⅡ concentration at 10 -8 ,10-7 ,10-6 mol/L,which reached peak at 10 -5 mol/L.There were significant differences in the activity of cardiomyocytes and expression levels of visfatin mRNA and protein when AngⅡconcentration at 10 -6 mol/L between experimental group and control group ( P <0.05).The OD value of cardiomyocytes,expression levels of visfatin mRNA and protein,expression levels of BNP protein were increased, with the time went on.The expression levels of visfatin mRNA and protein in PD123319 intervention group and AngⅡintervention group were significantly high than those in control group and telmisartan intervention group ( P <0.05).There were significant differences in the expression levels of visfatin mRNA and protein between AngⅡgroup and control group and between AG490 +AngⅡ group, SP600125 +AngⅡgroup and U0126 +AngⅡgroup ( P <0.05), moreover,which in AG490+AngⅡ group,SP600125+AngⅡ group and U0126 +AngⅡ group were significantly higher than those in control group ( P <0.05).Conclusion The enhancement of visfatin expression levels in AngⅡ-induced cardiomyocyte hypertrophy is mediated by AT1-R-JAK/STAT signal pathway.