不同比例n-6和n-3多不饱和脂肪酸调控NT-proBNP和hFABP保护急性心肌梗死后的心肌损伤

Different ratios of n-6 and n-3 polyunsaturated fatty acids regulating NT-proBNP and hFABP to protect myocardial injury after acute myocardial infarction

目的探讨不同比例的n-6和n-3多不饱和脂肪酸对急性心肌梗死大鼠心肌细胞的保护作用。方法采用连续注射异丙基肾上腺素的方法构建急性心梗大鼠模型。通过酶联免疫法检测大鼠血清中NTproBNP、hFABP和cTnI的水平;TTC和TUNEL染色评估心肌梗死面积和心肌细胞凋亡程度。Western blot和QPCR检测心梗标记基因和凋亡因子的表达。通过向心脏注射干扰NT-proBNP、hFABP、cTnI的慢病毒,进一步检测AMI心肌细胞的凋亡情况。结果日粮中添加n-6/n-3多不饱和脂肪酸比例1∶5和1∶10导致AMI大鼠在心梗发生后0、4、8和12h的NT-proBNP、hFABP和cTnI水平、心梗面积和心肌细胞凋亡均明显低于基础日粮饲喂的AMI大鼠;且1∶10比例的n-6/n-3多不饱和脂肪酸抑制效果最为明显。干扰AMI大鼠心肌NT-proBNP和hFABP导致cTnI、Bax表达降低,Bcl-2表达升高。结论日粮添加1∶10比例的n-6/n-3多不饱和脂肪酸能有效缓解急性心肌梗死的发生,且NT-proBNP和hFABP的表达水平是参与心梗后心肌细胞凋亡的重要因子。

Objective To investigate the protective effects of different proportions of n-6 and n-3 polyunsaturated fatty acids on cardiomyocytes in rats with acute myocardial infarction.Methods Acute myocardial infarction rat modelswere constructed by continuous injection of isoproterenol.The levels of NT-proBNP,hFABP and cTnI in rat serum were detected by enzyme-linked immunosorbent assay(ELISA).The myocardial infarct size and cardiomyocyte apoptosis were assessed by TTC and TUNEL staining.Western blot and QPCR were used to detect the expression of myocardial infarction marker gene and apoptotic factor.Apoptosis of AMI cardiomyocytes was further detected by injecting a lentivirus that interferes with NT-proBNP,hFABP,and cTnI into the heart.Results When dietary supplementation of n-6/n-3 polyunsaturated fatty acids was 1:5 and 1:10,the NT-proBNP,hFABP,cTnI levels,infarction size,and myocardial apoptosis were significantly lower than those of basal diet-fed AMI rats at 0,4,8 and 12 h after myocardial infarction,and the 1:10 ratio of n-6/n-3 polyunsaturated fatty acids was the most effective.Interfering with myocardial NT-proBNP and hFABP in AMI rats resulted in decreased expression of cTnI and Bax,and increased expression of Bcl-2.Conclusion Dietary supplementation of 1:10 ratio of n-6/n-3 polyunsaturated fatty acids can effectively alleviate the occurrence of acute myocardial infarction,and the expression levels of NT-proBNP and hFABP are important factors involved in cardiomyocyte apoptosis after myocardial infarction.