基于生物信息学与机器学习算法筛选并验证蛋白激酶D3为衰老心肌缺血损伤的关键基因OA

Objective To identify and validate protein kinase D3 as a key gene involved in aging myocardial ischemic injury using bioinformatics and machine learning approaches.Methods H9c2 cells were randomly assigned to the control group,the myocardial ischemic injury group,and the aging myocardial ischemic injury group.Cells in the control group were cultured routinely without additional treatments.The myocardial ischemic injury model was established by oxygen-glucose deprivation/reperfusion(OGD/R)in the myocardial ischemic injury group,while the aging myocardial ischemic injury model was induced by OGD/R combined with D-galactose in the aging myocardial ischemic injury group.The successful construction of the model was verified by using β-galactosidase staining,CCK8 method to detect cell survival rate,and RT-qPCR method to detect the expression levels of P16 and P21 mRNA.Transcriptomic sequencing analysis on cells was performed in the control group and the aging myocardial ischemic injury group.Principal component analysis and screening of differentially expressed genes were performed using DESeq2 software.Venn diagram was used to select intersection between differentially expressed genes and protein kinase genes to screen for differentially expressed protein kinase genes involved in aging myocardial ischemia injury.Least absolute shrinkage and selection operator(LASSO)Logistic regression and random forest(RF)were used to screen for key differentially expressed protein kinase genes in aging myocardial ischemic injury.RT-qPCR method was used to detect the protein kinase D3 mRNA expression level,and Western blotting was used to detect the protein kinase D3 expression level.Results The cell survival rate in the myocardial ischemic injury group was lower than that in the control group,and the expression levels of P16 and P21 mRNA were higher than those in the control group(P<0.05);the cell survival rate in the aging myocardial ischemia injury group was lower than that in the control group and myocardial ischemia injury group,and the expression levels of P16 and P21 mRNA were higher than those in the control group and myocardial ischemia injury group(P<0.05).A total of 1 079 differentially expressed genes were identified,including 894 upregulated genes and 185 downregulated genes.Nineteen differentially expressed protein kinase genes involved in aging myocardial ischemic injury were screened,and 3 key differentially expressed protein kinase genes were obtained through LASSO Logistic regression and RF,namely protein kinase D3,Zap70,and Hipk4.The protein kinase D3 mRNA expression level and protein kinase D3 expression level in the aging myocardial ischemic injury group were lower than those in the control group(P<0.05).Conclusion Protein kinase D3 is a key gene involved in aging myocardial ischemia injury.