[Astragalus injection mediates autophagy and myocardial remodeling in rats with ischemic cardiomyopathy through calumenin].

OBJECTIVE: To study the effects of astragalus injection on myocardial remodeling, calumenin and autophagy in rats with ischemic cardiomyopathy. METHODS: Thirty-six male SD rats were divided into normal control group, ischemic cardiomyopathy group and astragalus injection group, 12 in each group. Electrocardiogram (ECG) and echocardiography were performed before operation in three groups. Rats in ischemic cardiomyopathy group and astragalus injection group underwent thoracotomy and ligation of coronary artery for 20 minutes, then thoracic cavity was closed after reperfusion. In the astragalus injection group,10 g/kg body weight of Astragalus injection was injected once a week, four times in total. Four weeks after operation, rats in three groups were executed by echocardiography and their hearts were collected for Hematoxylin-Eosin (HE) staining and Van Gieson (VG) staining to observe myocardial pathological changes. Calumenin, LC3-I, LC3-II expressions and LC3-I/LC3-II ratio were detected by Western blot. RESULTS: Compared with ischemic cardiomyopathy group, the echocardiography and myocardial pathology of rats in astragalus injection group changed obviously, and the expressions of calumenin, LC3-I, LC3-II and LC3-I/LC3-II ratio changed significantly (P＜0.01). CONCLUSION: Astragalus injection has apparent inhibitory effect on ventricular remodeling and autophagy of myocardial cells in rats with ischemic cardiomyopathy, which may be mediated by calumenin.

[Effect of Astragalus injection on cardiomyocyte apoptosis, endoplasmic reticulum stress and expression of connexin in cardiomyopathy rats induced by adriamycin].

OBJECTIVES: To investigate the effect of Astragalus injection on cardiomyocyte apoptosis, endoplasmic reticulum stress and connexin protein in cardiomyopathy rats induced by adriamycin. METHODS: Thirty-six male Wister rats were randomly divided into control group (n=12), adriamycin(ADR) group (n=12) and Astragalus group (n=12). The normal saline (10 ml/kg body weight) was injected intraperitoneally in control group rats, ADR (2 mg/kg body weight) was injected intraperitoneally in ADR group rats, ADR (10 ml/kg body weight) and Astragalus injection (10 ml/kg body weight) were injected intraperitoneally in rats of astragalus group, one time a week, totle 3 times. By the end of the 7th week, the left ventricular end-diastolic diameter(LVEDD), left ventricular end-systolic diameter (LVESD) and left ventricular ejection fraction (LVEF) were measured by echocardiography. Then the rats in the three groups were sacrificed and the left ventricle section was stained by HE, Masson, uranyl acetate/lead citrate respectively, the cardiomyopathy and ultrastructural changes were observed under light microscope and transmission electron microscope. The apoptosis of rat cardiomyocyte were analyzed by TUNEL. The expression of connexin Cx43 and p-Cx43 was detected by immunohistochemistry. The expression of glucose-regulated protein 78 (Grp78),activating transcription factor 4 (ATF-4) and C/EBP homologous protein (CHOP) were detected by real time PCR. RESULTS: Compared with control group, LVEDD, LVESD increased and LVEF decreased, myocardial fibers were disordered and edematous, infiltrated by lymphocytes, the mitochondria were destroyed and vacuolized, and the number of cardiomyocyte apoptosis was increased(P<0.01) in ADR group. The expression of Grp78, ATF-4, CHOP and p-Cx43 were increased, and the expression of Cx43 was decreased in ADR group. However, compared with ADR group, LVEDD, LVESD decreased and LVEF increased, the cardiomyopathy and ultrastructural changes were significantly improved, the number of cardiomyocyte apoptosis was significantly decreased (P<0. 01); the expression of Grp78, ATF-4, CHOP and p-Cx43 decreased (P<0.01); the expression of Cx43 increased in Astragalus group (P<0.01). CONCLUSIONS: Astragalus injection may effectively improve the myocardial damage induced by adriamycin, its mechanism may be related to the inhibition of endoplasmic reticulum stress (ERS) and the decrease of phosphorylation of CX43 in cardiomyopathy rats induced by adriamycin.

MiRNA Signaling in Viral Myocarditis Novel and Unique Pathological Features.

BACKGROUND: Micro-RNAs (miRNAs) are small non-coding RNAs that modulate many target genes. Viral myocarditis is common cardiomyopathy, however, there is an absence of effective therapeutic strategies for viral myocarditis (VMC). The purpose of this research was to characterize changes in miRNAs expression in VMC mice. METHODS: Atrial myocytes were infected coxsackievirus B3 and miRNAs microarray was performed. miRNAs target predicted and the bioinformatics analysis was carried out by gene ontology (GO) and KEGG pathway analysis. To validate the results, Difference miRNAs were identified in heart of mice by real-time polymerase chain reaction (PCR). RESULTS: We identified 94 miRNAs that were differentially expressed (27 were up-regulated and 67 were down-regulated by at least 2.0-fold). Real time PCR analysis has confirmed that the expression levels of 7 miRNAs up-regulated, 18 miRNAs down-regulated. They were mainly involved in protein binding, small GTPase mediated signal transduction, protein phosphorylation by GO. Pathway analysis showed that a significant enrichment in several pathways related to cAMP signaling pathway, AMPK signaling pathway, RAS signaling pathway, Rap1 signaling pathway, ErbB signaling pathway, Oxytocin signaling pathway. CONCLUSIONS: Our results provide a better understanding of the mechanisms of viral myocarditis pathophysiology.