To Clarify The Effect Of Bauhinia Championii Flavone On Anti-myocardial Ischemia Injury Basing On Mi R-384-5p/ Beclin 1 Axis

Objective: The purpose of this study was to investigate the effect of Bauhinia Championii flavone(BCF)on myocardial ischemia and hypoxia and the underlying molecular mechanisms.Methods: H9c2 rat cardiomyocytes were cultured,and OGD model was established to simulate myocardial ischemia and hypoxia injury with or without BCF pretreatment.The cell morphology was observed by Giemsa staining,the cell viability was detected by CCK-8 kit,the contents of c Tn I and CK-MB in cells culture supernatants were detected by ELISA.Lentiviral infection was used to construct stable transgenic cells overexpressing or knocking down mi R-384-5p gene.Dual-luciferase reporter gene assay was conducted to verify the relationship between mi R-384 and Beclin 1.Autophagy flux of myocardial cells were detected by fluorescence microscope.The levels of autophagy-related genes or proteins expression were evaluated by q RT-PCR or Western blot.Results: Compared with the model group,BCF pretreatment significantly improved myocardial cells morphology and viability,decreased c Tn I and CK-MB contents,down-regulated LC3,p62 m RNA and cathepsin D protein expression,up-regulated p62 protein expression,as well as reduced LC3-II/LC3-I ratio and inhibited autophagy.Mi R-384-5p expression was down-regulated in H9c2 cell lines when subjected to hypoxia,while this suppression could be reversed by BCF pretreatment.Overexpressing mi R-384-5p increased cells survival rate,down-regulated LC3-II/LC3-I ratio and Beclin 1 protein expression,up-regulated p62,and decreased autophagy level.The dual-luciferase assay together with the fact that the protein expression of Beclin 1 was negatively correlated with mi R-384-5p gene expression verified Beclin 1 was a target protein of mi R-384-5p.Over-expressed mi R-384-5p enhanced the inhibitive effect of BCF on autophagy,while down-regulation of mi R-384-5p partially reversed the functions of BCF.On the other hand,Over-expressed Beclin 1 promoted the activation of autophagy and weakened the function of BCF on inhibitting autophagy.Conclusion: Bauhinia Championii flavone inhibited autophagy and decreased myocardial ischemia and hypoxia injury.The specific mechanism may be related to the regulation of micro RNA-384-5p targeting Beclin 1-mediated autophagy.