柚皮素对慢性心力衰竭大鼠心肌纤维化及激活素A/卵泡抑素系统的影响

Effects of Naringenin on Myocardial Fibrosis and Activin A/follistatin System in Rats with Chronic Heart Failure

目的研究柚皮素(Naringenin,NAR)对慢性心力衰竭(Chronic heart failure,CHF)大鼠心肌纤维化的影响,并探讨作用机制。方法构建CHF大鼠模型,随机分为CHF模型组(CHF)、NAR低剂量组(LNAR)、中剂量组(M-NAR)和高剂量组(H-NAR),另设置假手术组(Sham),每组10只。采用超声心电图检测大鼠心功能;HE染色和Masson染色观察心肌组织病理学变化;碱水解法测定心肌组织羟脯氨酸(Hydroxyproline,HYP)含量并计算胶原蛋白含量;qRT-PCR检测心肌组织激活素A(Activin A,Act A)和卵泡抑素(Follistatin,FS)mRNA表达水平;Western blot检测心肌组织Act A、FS、Ⅰ型胶原蛋白(CollagenⅠ)、Ⅲ型胶原蛋白(CollagenⅢ)、Smad2、Smad3、p-Smad2及p-Smad3蛋白表达水平。结果与Sham组比较,CHF组大鼠肌纤维排列紊乱,细胞肿胀,纤维化程度较高,左心室舒张末内径(Leftventricularenddiastolic dimension,LVEDD)、左心室收缩末内径(Left ventricular endsystolic dimension,LVESD)、胶原蛋白含量和Act A、CollagenⅠ、CollagenⅢ蛋白表达水平、p-Smad2/Smad2及p-Smad3/Smad3比值均显著升高(P<0.05),而左心室射血分数(Left ventricular ejection fraction,LVEF)和FS表达水平显著降低(P<0.05)。与CHF组比较,M-NAR组和H-NAR组大鼠心肌组织病理变化及纤维化程度得到改善,LVEDD、LVESD、胶原蛋白含量和Act A、CollagenⅠ、CollagenⅢ蛋白表达水平、p-Smad2/Smad2及p-Smad3/Smad3比值均显著降低(P<0.05),LVEF和FS表达水平显著升高(P<0.05)。与L-NAR组比较,中、高剂量NAR干预对CHF大鼠心肌纤维化和Act A/FS系统紊乱的改善效果更显著(P<0.05)。结论NAR可抑制CHF大鼠心肌纤维化,其作用机制可能与调节Act A/FS系统有关。

Objective To study the effect of naringenin(NAR)on myocardial fibrosis in rats with chronic heart failure(CHF)and its mechanism.Methods The rat model of CHF was established and randomly divided into CHF model group(CHF),NAR low dose group(L-NAR),medium dose group(M-NAR)and high dose group(H-NAR),with 10 rats in each group.In addition,sham operation group(Sham)was set up.The cardiac function of rats was detected by ultrasonic electrocardiogram.HE staining and Masson staining were used to observe the pathological changes of myocardium.The content of hydroxyproline(HYP)in myocardium was determined by alkaline hydrolysis method,and the content of collagen was calculated.The mRNA expression levels of activin A(Act A)and follistatin(FS)in myocardium were detected by qRT-PCR.The protein expression levels of Act A,FS,CollagenⅠ,CollagenⅢ,Smad2,Smad3,p-Smad2 and p-Smad3 were detected by Western blot.Results Compared with Sham group,the arrangement of muscle fibers in CHF group was disordered,cells were swollen,and the degree of fibrosis was higher.The left ventricular end diastolic dimension(LVEDD),left ventricular end systolic dimension(LVESD),collagen content,and the expression levels of Act A,Collagen I,CollagenⅢ,p-Smad2/Smad2,and p-Smad3/Smad3 ratios were significantly increased(P<0.05),The left ventricular ejection fraction(LVEF)and FS expression level were significantly decreased(P<0.05).Compared with CHF group,the pathological changes and fibrosis degree of myocardial tissue in M-NAR group and HNAR group were improved.LVEDD,LVESD,collagen content and the expression levels of Act A,CollagenⅠ,CollagenⅢ,p-Smad2/Smad2,and p-Smad3/Smad3 ratios were significantly decreased(P<0.05),while LVEF and FS expression levels were significantly increased(P<0.05).Compared with L-NAR group,medium and high-dose NAR intervention was more effective in improving myocardial fibrosis and Act A/FS system disorder in CHF rats(P<0.05).Conclusion NAR can inhibit myocardial fibrosis in CHF rats,and its mechanism may be related to the regulation of Act A/FS system.