To Study The Role Of AngⅡ/PI3K/Akt/KDM5A Pathway In Cardiac Fibrosis Based On Transcriptomics

Background and Objective:Cardiac fibrosis refers to the excessive production and deposition of extra cellular matrix（ECM）components in the heart caused by various reasons,leading to severe scarring,tissue stiffness and function impairment of the heart.With the aging of the population,the incidence and mortality of cardiovascular disease（CVDS）related to cardiac fibrosis are constantly on the rise,reducing the quality of life of patients with CVDS and increasing medical costs.In vitro studies have proved that angiotensin Ⅱ（Ang Ⅱ）can increase the activation and proliferation of fibroblasts,and recent studies have found that as an effectant mediated by PI3K/Akt signaling pathway,Lysine-specific demethylase 5A（KDM5A）gene is associated with heart failure,congenital heart disease and arrhythmogenic right ventricular cardiomyopathy,while the relationship between angiotensin Ⅱ,Ang Ⅱ and KDM5A has not been studied clearly.If the expression mechanism of KDM5A in the process of cardiac fibrosis can be confirmed,it can also provide a new therapeutic target for the treatment of cardiac fibrosis.The purpose of this study was to investigate the role of KDM5A in cardiac fibrosis by bioinformatics analysis.Methods:In order to further investigate the role of KDM5A in cardiac fibrosis,the experiment was divided into the following parts:（1）Four ventricular samples were used in cell culture from myocardial tissue obtained from 10 patients with DCM（dilated heart disease）.Six samples were used to verify the results of the bioinformatics analysis.The left atrial appendage（LAA）was a control sample obtained during a previous valve replacement.（2）angiotensin Ⅱ（Ang Ⅱ）was added into cultured CFs（cardiac fibroblasts）at different concentrations,and cell activity was evaluated by cell counting kit 8（CCK-8,Abbkine,USA）.Western blotting confirmed that KDM5A is regulated by angiotensin Ⅱ（Ang Ⅱ）through the PI3k/Akt signaling pathway.（3）Differentially expressed genes（DEGs）were analyzed by transcriptomics.Key genes in the module were analyzed by Gene Ontology（GO）and Kyoto Encyclopedia of Genes and Genomes（KEGG）pathway enrichment.Results:The results of CCK-8 analysis showed that the cell proliferation ability was significantly higher at 1×10^-7mol/L and at 1×10^-7mol/L,respectively,at 24 h and48 h.Therefore,the concentration(1×10^-7mol/L)was used in this study.Western blotting results showed that no changes in the total protein level of PI3K were observed24 hours after LY294002（PI3K inhibitor）treatment,but the expression level of phosphorylated PI3K was significantly reduced.Similarly,phosphorylated Akt expression levels are significantly reduced.Angii-treated CFs can induce a stable increase in KDM5A,suggesting that Ang Ⅱ up-regulates the expression of KDM5A through PI3K/Akt signaling pathway.Bioinformatics analysis showed that KDM5A-regulated DEG was mainly enriched in PI3K-Akt signaling pathway,focal adhesion,and ECM receptor interaction.Conclusion:KDM5A is one of the key regulatory factors in cardiac remodeling.This study provides new insights into the molecular mechanisms,biomarkers and treatment of cardiac fibrosis.