| Objective Heart failure is the final stage in the irreversible progression of many cardiovascular diseases,and myocardial remodeling is one of the major and important pathological changes in heart failure.Myocardial hypertrophy and myocardial fibrosis during ventricular remodeling are the main pathological changes.How to stop myocardial cell hypertrophy and functional changes is of great significance for the treatment of ventricular remodeling.miRNA is a kind of RNA single strand encoded by miRNA gene,which does not encode protein and is approximately 21 bases in length.It is widely involved in the regulation of physiological and pathological states of cells and plays an important role in the maintenance of cell function.In the process of cardiac hypertrophy,miR-26a-5p was found to have a differential expression,which provided a theoretical basis for our selection of miR-26a-5p,and explored its regulation of myocardial cells.Prediction of miR-26a-5p by target gene prediction software may be through the regulation of the target gene ULK1 to play a role in exploring the molecular regulation mechanism.Studies on changes in miR-26a-5p and ULK1 and autophagy activity are rare,so this study will focus on regulating autophagic activity of miR-26a-5p by targeting the ULK1 gene,further investigating the role of miR-26a-5p in The molecular regulation mechanism of cardiac hypertrophy provides a new direction for delaying or even reversing cardiac hypertrophy.Methods 1 to 3 days old newborn neonatal rats were selected from Sprague Dawley rats.The ventricle of the heart was removed and the ventricular tissue was digested with trypsin digestion.The myocardium was isolated and purified according to the adherence difference in the time between myocardial cells and cardiac fibroblasts.The cells were seeded in 6-well plates and the cell morphology was observed under microscope.After 24 hours of cell culture,miR-26a-5p mimic and inhibitor and their respective controls were transfected into cardiomyocytes by using liposome transfection method.RNA and total protein were extracted after 48 hours,and miR-26 a was detected by real-time fluorescent quantitative PCR.miR-26a-5p,ULK1 m RNA relative expression;ULK1,LC3,autophagy-related protein p62 expression levels were detected by Western blot;autophagy-related protein LC3 expression was detected by flow cytometry;transmission electron microscopy was used to detect cell autophagic vacuoles formation.Results The primary myocardial cells were isolated,and the cells were rounded or kidney-shaped,with autonomous beats.A certain concentration of Ang Ⅱ stimulatedmyocardial cell hypertrophy,increased hypertrophy-related gene expression,and induced ULK1 expression and autophagy.Increased activity;ULK1 si RNA interferes with the expression of ULK1 can reduce the increase of autophagy activity and hypertrophy of cardiomyocytes mediated by Ang Ⅱ.Mir-26a-5p mimic and inhibitor can simulate overexpression and absence of mir-26a-5p.As the expression of mir-26a-5p changes,the transcription and protein levels of the ULK1 gene change in the same time.After myocardial cells transfected with mir-26a-5p mimic,the expression of LC3 Ⅱ/Ⅰ protein was decreased and the expression of autophagy associated protein P62 was increased.On the contrary,the expression of LC3 LC3 Ⅱ/Ⅰ protein and the expression of autophagy associated protein P62 was decreased,suggesting that mir-26a-5p inhibits the autophagy activity of myocardial cells induced by Ang Ⅱ.Conclusions In primary cardiomyocytes,miR-26a-5p can regulate cardiomyocyte hypertrophy which was induced by Ang Ⅱ.Inhibiting the expression of ULK1 protein on the autophagy pathway,Mi R-26a-5p affect cell function and further regulate myocardial cell Phagocytic activity and plays a role in regulating cardiac hypertrophy. |
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