Qiliqiangxin Ameliorate Hypoxia-induced Cadiomyocyte Injury Via Downregulation Of MicroRNA-25

Research background:MicroRNAs(mi RNAs or miRs)is a class of noncoding RNA with a length of about 22 nucleotides and it is known that mi Rs is involved in various aspects of cardiovascular biology,such as myocardial hypertrophy,myocardial fibrosis,myocardial contraction and angiogenesis.Qiliqiangxin(QL),a traditional Chinese medicine compound,is extracted Astragalus,ginseng,aconite and other Chinese herbal medicine composition.The present study showed that Qiliqiangxin by the regulation of mi RNAs in the improvement of a series of pathophysiological role in heart failure,such as enhanced myocardial contraction,improve myocardial remodeling,reduce cell apoptosis and the myocardial inflammation,improve angiogenesis,and so on.The expression of miR-25 in myocardial cells was significantly increased,and Wahlquist et al.increased the expression of SERCA2 a induced by inhibition of miR-25 in the treatment of heart failure induced by mouse thoracic aortic coarctation(TAC)model.However,Qiliqiangxin is rarely reported to play a role in improving heart failure by regulating mi R-25.Objective:To investigate the mechanism of injury of the primary myocardial cells of Qiliqiangxin improved under hypoxic conditions.Methods:Primary cultured neonatal rat cardiomyocytes were subjected to hypoxia and drug intervention.Detection of miR-25 and its downstream SERCA2 a RNA and its protein by RT-PCR and Western Blot,and Cell calcium concentration was detected by fluo 3am.Results:Compared with the control group,the expression of miR-25 in hypoxia group increased the level of miR-25 in Qiliqiangxin + hypoxia group than in hypoxia group decreased.SERCA2 a RNA and protein increased and calcium concentration decreased in hypoxia group in Qiliqiangxin + hypoxia group than in hypoxia group.Conclusion:Qiliqiangxin on myocardial hypoxia model via down-regulation of miR-25 expression level,thereby increasing the mi R-25 downstream of the SERCA2 a gene and protein changes,reduce myocardial cell calcium concentration,so as to reduce the damage of myocardial cells.This is probably one of the molecular mechanism of Qiliqiangxin to improve myocardial function.