葛根素激活Sirt1抑制炎症和纤维化减轻压力负荷诱导小鼠心肌肥厚的研究

Puerarin Alleviates Pressure Overload-induced Cardiac Hypertrophy in Mice by Activating Sirt 1 and Inhibiting Inflammation and Fibrosis

目的探讨葛根素(Pue)在小鼠压力负荷诱导的心肌肥厚中的作用及机制。方法采用小鼠主动脉弓缩窄术(TAC)制备心肌肥厚模型。将48只C57/bl小鼠随机分为假手术组(Sham组)、TAC组、Pue干预TAC组(Pue+TAC组)和Pue联合EX527干预TAC组(Pue+EX527+TAC组),每组12只。Pue+TAC组术后给予65 mg/kg Pue饮用,Pue+EX527+TAC组给予腹腔注射EX527,持续4周,模型组有2只死亡。小动物超声检测左心室射血分数(LVEF)和左心室短轴缩短率(LVFS),RT-PCR检测钠尿肽(ANP)、脑钠肽(BNP)和β-肌球蛋白重链(β-MHC)的mRNA水平,ELISA检测血清中肿瘤坏死因子-α(TNF-α)和白介素-1β(IL-1β)的含量,测量4组心脏质量与体质量比值(HW/BW),HE染色和Masson染色分别观察4组心肌细胞横截面积和纤维化程度,Western blot检测CollagenⅠ、α-SMA、沉默信息转录调节因子1(Sirt1)和Ac-FOXO1蛋白的表达。结果与Sham组比较,术后4周,TAC组LVEF和LVFS值显著降低,ANP、BNP和β-MHC的mRNA水平及血清TNF-α和IL-1β含量增加,心肌细胞横截面积明显增大,纤维化加重,CollagenⅠ和α-SMA蛋白表达增加,Sirt1蛋白水平显著降低,Ac-FOXO1水平增加(P<0.01);与TAC组比较,用Pue处理后,可显著提高心脏LVEF和LVFS,降低ANP、BNP和β-MHC的mRNA水平以及血清中TNF-α和IL-1β含量,减小心肌细胞横截面积和纤维化程度,增高Sirt1蛋白水平,降低Ac-FOXO1水平(P<0.01)。结论Pue可通过抑制心脏炎症反应和纤维化,减轻压力负荷诱导的病理性心肌肥厚。

Objective To investigate the role of puerarin(Pue)in pressure overload-induced cardiac hypertrophy in mice and the underlying mechanisms.Methods A mouse model of cardiac hypertrophy was prepared by transverse aortic constriction(TAC).Forty-eight C57BL mice were randomly divided into the Sham group,TAC group(TAC),TAC+puerarin(Pue+TAC)group and TAC plus puerarin and EX527(Pue+EX527+TAC)group(n=12 in each group).The drug administration groups were given 65 mg/kg Pue with water for drinking or intraperitoneal injection of EX527 for 4 consecutive weeks.Two mice died in the model group.Small animal ultrasound was used to detect left ventricular ejection fraction(LVEF)and left ventricular fractional shortening(LVFS),and the mRNA levels of natriuretic peptide(ANP),brain natriuretic peptide(BNP)andβ-myosin heavy chain(β-MHC)were determined by RT-PCR.The levels of tumor necrosis factorα(TNF-α)and interleukin-1β(IL-1β)in serum were detected by ELISA.After four weeks,the heart weight/body weight(HW/BW)ratio of the four groups was measured.HE staining and Masson staining were used to observe the cross-sectional area and fibrosis of cardiomyocytes of the four groups.Western blot was used to detect the protein levels of Collagen I,α-SMA,Sirt1 and Ac-FOXO1.Results Compared with the Sham group,the level of LVEF and LVFS were significantly decreased in the TAC group at 4 weeks after surgery,while the mRNA levels of ANP,BNP andβ-MHC,as well as the content of TNF-αand IL-1βin serum were increased in the TAC group.Meanwhile,the cross-sectional area of cardiomyocytes and fibrosis were significantly increased respectively.The protein levels of Collagen I andα-SMA and the Ac-FOXO1 were increased,while the protein level of Sirt1 was decreased(P<0.01).Compared with TAC group,treatment with Pue can significantly increase the levels of LVEF and LVFS,while decrease the mRNA levels of ANP,BNP andβ-MHC,the content of TNF-αand IL-1β,the cross-sectional area of myocardial cells and fibrosis.In addition,the protein levels of Sirt1 were increased,while the Ac-FOXO1 was decreased(P<0.01).Conclusion Pue can alleviate pressure overload-induced pathological myocardial hypertrophy by inhibiting inflammatory response and fibrosis.