Effect of moxibustion on PTEN/mTOR signalling pathway and myocardial fibrosis in rats with chronic heart failure
Objective To observe the effects of moxibustion on myocardial pathological morphology,α-smooth muscle actin(α-SMA)and chromosome 10 deletion phosphatase and tensin homologous protein(PTEN)/mammalian target of rapamycin(mTOR)signalling pathway in rats with chronic heart failure(CHF),and to explore the possible mechanism of moxibustion in attenuating myocardial fibrosis in rats with CHF.Methods According to the random number table method,60 male SD rats were divided into the normal group(n=10)and the surgery group(n=50),and the rats in the surgery group were ligated the left coronary artery to replicate the CHF model.According to the random number table method,40 successfully modelled rats were divided into the model group,the moxibustion group,the bpV(phen)group,and the moxibustion+bpV(phen)group,with 10 rats in each group.The normal and model groups were not given any intervention;in the moxibustion group,customized moxa sticks were used to moxibrate the bilateral"Feishu"(BL13)and"Xinshu"(BL15)on the back of the rats for 30 min at each point once a day;the bpV(phen)group was injected intraperitoneally with the bpV(phen)solution(0.15 mg/kg)twice a week;the moxibustion+bpV(phen)group was based on the bpV(phen)group,and moxibustion was applied according to the moxibustion group.The intervention was carried out for 4 weeks.The general conditions of rats,such as feeding and activity were observed;HE staining was used to detect morphological changes of the cardiomyocytes;Masson staining was used to detect myocardial fibrosis;the cardiac echocardiography was used to detect ejection fraction(EF)and fractional shortening(FS);real-time PCR was used to detect the mRNA expressions of PTEN and mTOR in the cardiac muscle tissues;protein expressions of PTEN,mTOR,α-SMA in rat myocardial tissue were detected by Western blotting.Results Compared with the normal group,rats in the model group had altered cardiomyocyte morphology,severe damage to myocardial fiber structure,significantly lower EF,FS,and mTOR mRNA and protein expressions,and significantly higher PTEN,α-SMA protein expressions and PTEN mRNA expression(P<0.05).Compared with the model group,myocardial ultrastructural damage was attenuated in the moxibustion group,bpV(phen)group,and moxibustion+ bpV(phen)group,and EF,FS,and mRNA and protein expressions of mTOR were significantly higher,α-SMA protein expression was significantly lower,and mRNA and protein expressions of PTEN were significantly lower(P<0.05).Compared with the moxibustion+bpV(phen)group,myocardial ultrastructural damage was worsen in the moxibustion and bpV(phen)groups,with significantly lower EF,FS,and mRNA and protein expressions of mTOR,significantly higher α-SMA protein expression,and significantly higher mRNA and protein expressions of PTEN(P<0.05).Conclusion Moxibustion can improve the pathological morphology and function of cardiomyocytes and attenuate myocardial fibrosis in rats with CHF,and its mechanism may be related to the down-regulation of PTEN expression,and then the up-regulation of mTOR expression.