Objective To predict and preliminarily validate potential shared key genes involved in cardiac complications caused by influenza A virus(IAV)and severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infections.Methods Differentially expressed genes(DEGs)associated with cardiac complications were obtained from the Gene Expression Omnibus(GEO)database.A hierarchical intersection strategy was applied.First,cardiac complication related DEGs were overlapped with 2 independent virus related gene sets:3 454 human genes linked to IAV infection in GeneCards and 333 human protein-coding genes interacting with SARS-CoV-2 in the Human Protein Atlas.The 2 overlap results were then intersected to yield 22 hub genes.Lasso regression,random forest(RF)and support vector machine algorithms(SVM)were employed to refine this list.Predicted genes were validated in vitro in H1N1-infected human cardiomyocyte AC16 cells and in vivo in IFITM3 knockout mice challenged with H1N1,assessing transcriptional changes.Results A total of 22 hub genes were identified through integrative bioinformatics analysis.Application of the 3 machine learning algorithms resulted in 5 common key genes:ACE2,TBK1,NUP210,PUSL1,and MEPCE.In vitro infection of AC16 cells with H1N1 revealed dynamic transcriptional changes in all 5 genes post-infection(P<0.05).In vivo experiments using H1N1-infected IFITM3 knockout mice confirmed the dynamic mRNA expression changes of these 5 genes,consistent with the in vitro results(P<0.05).Conclusion By combining multilayered bioinformatics analysis with 3 machine learning approaches,5 common key genes are identified:ACE2,TBK1,NUP210,PUSL1 and MEPCE.Validation in H1N1 infection models confirms their relevance to IAV-induced cardiac complications.

The key pathogenesis of coronary heart disease （CHD） is spleen deficiency and phlegm stasis， and dysfunctional high-density lipoprotein （dys-HDL） may be the biological basis for the occurrence of CHD due to spleen deficiency and phlegm stasis. Considering the biological properties and effects of high-density lipoprotein （HDL）， it is believed that the structure and components of HDL are abnormal in the state of spleen deficiency which led to dys-HDL； and dys-HDL contributes to the formation of atherosclerotic plaques through two major pathways， namely， mediating the dysfunction of endothelial cells and mediating the foaminess of macrophages and smooth muscle cells， thus triggering the development of CHD. It is also believed that dys-HDL is a microcosmic manifestation and a pathological product of spleen deficiency， and spleen deficiency makes foundation for the production of dys-HDL； dys-HDL is also an important biological basis for the phlegm-stasis interactions in CHD. The method of fortifying spleen， resolving phlegm， and dispelling stasis， is proposed as an important principle in the treatment of CHD by traditional Chinese medicine， which can achieve the therapeutic purpose by affecting the changes in the structure and components of dys-HDL， thus revealing the scientific connotation of this method， and providing ideas for the diagnosis and treatment of CHD by traditional Chinese medicine.