Integration analysis using bioinformatics and experimental validation on cellular signalling for sex differences of hypertrophic cardiomyopathy

Abstract

There is a paucity of research examining the molecular mechanisms underlying sex differences of clinical phenotypes and the prognosis in hypertrophic cardiomyopathy (HCM). The dataset GSE36961 was retrieved from Gene Expression Omnibus (GEO) database and comprehensive bioinformatics was employed to identify the core genes linked to sex differences in HCM patients. Additionally, gene set enrichment analysis (GSEA) was conducted to detect downstream signalling pathways. Furthermore, experimental validation was carried out using hearts from spontaneously hypertensive rats (SHRs). A comprehensive analysis revealed the identification of 208 differentially expressed genes (DEGs) in female patients with HCM with a notable downregulation of seven core genes. Notably, there were sex differences in the expression of ras dexamethasone-induced protein 1 (RASD1) and myosin 6 (MYH6) in HCM. Gene ontology (GO) analysis and GSEA demonstrated an enrichment of autophagy-related processes in disease progression in HCM females. Specifically, spearman's correlation analysis revealed a positive correlation between nicotinamide phosphoribosyl transferase (NAMPT) and RASD1 levels, particularly among female patients (R = 0.569, p < 0.001). Additionally, animal models confirmed that cardiac hypertrophy was more pronounced in SHR females compared to males. SHR females exhibited lower mRNA and protein expressions of RASD1 and NAMPT, which were associated with impaired autophagy. In this study, bioinformatics and validation using external data sets and animal models of left ventricular hypertrophy suggested that the RASD1/NAMPT axis is potentially a crucial mechanism underlying the elevated risk of cardiovascular disorders in HCM females, also pointing potentially prognostic biomarkers.