Siwei Tumuxiang Powder Ameliorates Mechanical Stretch-induced Hypertrophy of H9c2 Cardiomyocytes by Regulating the MiR-34a-5p/Notch1 Signaling Pathway
Objective To investigate the protective effect and mechanism of siwei tumuxiang powder(STP)on the model of H9c2 cardiomyocytes hypertrophy induced by mechanical stretching in rats.Methods The STP drug-containing serum and the hypertrophic cell model were prepared,and the optimal dose and time of action of STP drug-containing serum were determined.The expressions of at-rial natriuretic peptide(ANP),brain natriuretic peptide(BNP),miR-34a-5p,Notch1 and other factors in H9c2 cardiomyocytes were detected to verify whether STP exerted a protective effect on H9c2 cardiomyocytes by regulating the miR-34a-5p/Notch1 pathway.Results The optimal dose(0.972g/kg)of STP drug-containing serum was low-dose,and the action time was 24 hours.STP de-creased the expressions of ANP,BNP and miR-34a-5p in model cells(P<0.05).Transfection of miR-34a-5p mimic reversed the effect of STP on ANP and BNP expressions(P<0.05).Knocking down Notch1 by siRNA reversed the effect of STP on ANP and BNP ex-pressions(P<0.05).Notch1 was the direct target gene of miR-34a-5p,and miR-34a-5p decreased the expression of Notch1(P<0.05).After STP intervention,the expression of Notch1,NICD1 and Hes1 proteins were decreased.Transfection of miR-34a-5p mim-ic reversed the effect of STP on the expressions of Notch1,NICD1 and Hes1 proteins(P<0.05).Conclusion STP exerts a protective effect on mechanical stretch-induced H9c2 cardiomyocyte hypertrophy by miR-34a-5p to negatively regulate the Notch1 signaling pathway.