虎杖苷抑制高糖引起新生鼠心肌细胞钙漏流的作用及其机制研究

The mechanism of Polydatin inhibits calcium leakage induced by high glucose in neonatal cadiomyocyte

目的研究虎杖苷（polydatin,PD）抑制高糖引起心肌细胞局部钙信号紊乱的机制,探讨其对糖尿病心肌病的保护作用。方法 分离1-3 d SD大鼠乳鼠心肌细胞,随机分为四组：对照组、高糖组、虎杖苷组和高糖＋虎杖苷组。培养48 h后采用激光共聚焦显微成像技术检测局部钙释放单位钙火花发放频率及其形态;利用Western blot方法检测受磷蛋白PLB和肌浆网SERCA 2a蛋白的表达水平。结果 高糖组心肌细胞钙自发钙火花发放水平显著增加（P〈0.01）,且略微增加钙火花时程。在虎杖苷组中,高糖引起的高频钙火花发放显著抑制（P〈0.01）。与对照组相比,高糖增加心肌细胞内静息期细胞内钙离子水平,给予PD治疗则抑制高糖引起钙超载。PD抑制高糖引起的心肌细胞ROS水平增加。高糖下调PLB和SERCA 2a蛋白的表达。结论 PD通过降低细胞自发钙火花的频率,抑制肌浆网钙漏流、增加钙稳定性,调节PLB/SERCA 2a蛋白比例,从而有效纠正高糖所致心肌细胞局部钙调控紊乱。因此,PD可能在糖尿病心肌病患者中发挥着重要的心肌保护作用。

Objective To study the mechanism of polydatin （PD） inhibited the local calcium signal disorder induced by high glucose in neonatal rat ventricular myocytes, to investigate its protective effect on diabetic cardiomyopathy. Methods Cardiomyocytes were isolated from 1-3 days sprague-dawley neonatal rat, and were randomly divided into four groups： control group, high glucose group, polydatin group and high glucose＋polydatin group. Confocal imaging calcium spark, the elementary Ca^2＋ release event reflecting RyR activity in intact cell after 48 h, as well as the Western blot were performed in cultured neonatal rat ventricular myocytes. Results The results show that high glucose increased the frequency of calcium sparks （P〈0.05）, a slight increase in the calcium spark duration（FDHM）.The high frequency spon- taneous calcium spark induced by high glucose calcium sparks were significantly inhibited by polydatin（P〈0.01）. Com- pared with the control group, the high glucose increased intracellular resting Ca2＋ levels in neonatal rat ventricular my- ocytes, and PD treatment against the effect of high glucose induced calcium overload. PD inhibited the increase of ROS levels in cardiomyocytes induced by high glucose. The protein expression of phospholamban and SERCA 2a were down- regulation by high glucose. Conclusion PD can reduce the frequency of spontaneous calcium sparks, reduce calcium leakage in the cardiomyocyte plasma network, increase the stability of calcium, regulate the ratio of PLB/SERCA 2a protein, thereby corrected the local calcium regulation disorder of neonatal cardiomyocyte induced by high glucose. Therefore, PD may play an important role in myocardial protection in patients with diabetic cardiomyopathy.