摘要
目的 探究沙库巴曲缬沙坦(LCZ696)调节第10号染色体缺失的磷酸酶及张力蛋白同源基因(PTEN)/蛋白激酶B(AKT)/转录因子EB(TFEB)信号通路对慢性心力衰竭(CHF)大鼠心肌纤维化的影响.方法 采用腹腔注射盐酸多柔比星注射液(1.5 mg/kg)的方式制备大鼠CHF模型,并将造模成功的SPF级SD雄性大鼠随机分为CHF模型组(CHF组)、低剂量LCZ696组(LCZ696-L组)、高剂量LCZ696组(LCZ696-H组)和高剂量LCZ696+PTEN抑制剂Bpv组(LCZ696-H+Bpv组),每组大鼠各12只.另取12只大鼠作为空白对照组(Normal组).LCZ696-L组、LCZ696-H组分别给予大鼠LCZ696混悬液30、60 mg/kg的剂量灌胃,LCZ696-H+Bpv组大鼠除灌胃LCZ696混悬液外,腹腔注射0.2 mg/kg Bpv;Normal组和CHF组大鼠给予生理盐水.给药4周后,行心脏超声检测大鼠心功能的变化.HE染色观察大鼠心肌组织的形态学变化.Masson染色观察心脏心肌纤维化和测定心肌胶原面积.ELISA法检测大鼠血清中N末端脑钠肽前体(NT-proBNP)、肌酸激酶(CK)水平.Western Blot检测大鼠心肌组织中PTEN/AKT/TFEB信号通路相关蛋白与纤维化相关蛋白Ⅰ型胶原蛋白(Collage-Ⅰ)、Ⅲ型胶原蛋白(Collage-Ⅲ)的表达水平.结果 CHF组较Normal组大鼠LVFS、LVEF、心肌组织PTEN、TFEB蛋白表达显著降低(P＜0.05),LVEDD、LVESD、心肌组织病理学评分、心肌组织CVF、血清NT-proBNP、CK水平、心肌组织p-AKT/AKT水平、Collage-Ⅰ、Collage-Ⅲ蛋白表达显著升高(P＜0.05),心肌横纹紊乱,心肌纤维化明显,有大量炎性细胞浸润.与CHF组相比,LCZ696-L组、LCZ696-H组大鼠相应指标变化与上述相反(P＜0.05),大鼠的心肌组织病理损伤有所改善,心肌组织纤维化减轻.PTEN抑制剂Bpv减弱了LCZ696对CHF大鼠心肌纤维化的缓解作用.结论 LCZ696可能通过激活PTEN、抑制Akt和促进TFEB的表达,进而缓解CHF大鼠的心肌纤维化.
Abstract
Objective To investigate the influence of sakubatril-valsartan(LCZ696)on myocardial fibrosis through regulating signaling pathway of phosphatase and tensin homology deleted on chromosome 10/protein kinase B/transcription factor EB(PTEN/Akt/TFEB in rats with chronic heart failure(CHF).Methods The rat model of CHF was established by intraperitoneal injection of doxorubicin hydrochloride(1.5 mg/kg).The successfully modeled SPF grade SD male rats were divided randomly into CHF group,low-dose LCZ696 group(LCZ696-L group),high-dose LCZ696 group(LCZ696-H group)and high-dose LCZ696+Bpv(PTEN inhibitor)group(LCZ696-H+Bpv group,each n=12).Other rats were chosen into normal group(n=12).The LCZ696-L group and LCZ696-H group were orally given LCZ696 suspension(30 mg/kg,60 mg/kg),and LCZ696-H+Bpv group was additionally given intraperitoneal injection of Bpv(0.2 mg/kg).The normal group and CHF group were orally given normal saline(NS).After 4 weeks,the changes of heart function were detected by using cardiac ultrasonography.The morphological changes of myocardial tissue were observed after HE staining.The myocardial fibrosis and myocardial collagen area were observed and detected after Masson staining.The levels of serum N-terminal pro-brain natriuretic peptide(NT-proBNP)and creatine kinase(CK)were detected by using ELISA.The expressions of collage-Ⅰ and collage-Ⅲrelated to PTEN/Akt/TFEB signal pathway and myocardial fibrosis were detected by using Western blotting assay.Results The expressions of left ventricular fraction shortening(LVFS),left ventricular ejection fraction(LVEF),PTEN and TFEB decreased significantly(P＜0.05),and levels of left ventricular end-diastolic diameter(LVEDD),left ventricular end-diastolic diameter(LVEDD),pathological scores of myocardial tissue,collagen volume fraction(CVF),NT-proBNP,CK,p-Akt/Akt,collage-Ⅰ and collage-Ⅲ increased significantly(P＜0.05)in CHF group compared with normal group.There were disordered myocardial striations,significant myocardial fibrosis and a large amount of inflammatory cell infiltration in CHF group.The changes of corresponding indexes were contrary to the above ones(P＜0.05),and of myocardial pathological damage and myocardial fibrosis were relieved in LCZ696-L group and LCZ696-H group compared with CHF group.Bpv weakened the alleviating effect of LCZ696 on myocardial fibrosis in CHF rats.Conclusion LCZ696 can relieve myocardial fibrosis through activating,PTEN,inhibiting Akt and promoting TFEB expression in CHF rats.
基金项目
新疆维吾尔自治区自然科学基金资助项目(2021D01C176)
维普
万方数据