Systems genetics analysis defines importance of TMEM43/ for cardiac- and metabolic-related pathways.

Broad cellular functions and diseases including muscular dystrophy, arrhythmogenic right ventricular cardiomyopathy (ARVC5) and cancer are associated with transmembrane protein43 (TMEM43/). The study aimed to investigate biological roles of through genetic regulation, gene pathways and gene networks, candidate interacting genes, and up- or downstream regulators. Cardiac transcriptomes from 40 strains of recombinant inbred BXD mice and two parental strains representing murine genetic reference population (GRP) were applied for genetic correlation, functional enrichment, and coexpression network analysis using systems genetics approach. The results were validated in a newly created knock-in -S358L mutation mouse model (Tmem43) that displayed signs of cardiac dysfunction, resembling ARVC5 phenotype seen in humans. We found high levels among BXDs with broad variability in expression. Expression of highly negatively correlated with heart mass and heart rate among BXDs, whereas levels of highly positively correlated with plasma high-density lipoproteins (HDL). Through finding differentially expressed genes (DEGs) between Tmem43 mutant and wild-type (Tmem43) lines, 18 pathways (out of 42 found in BXDs GRP) that are involved in ARVC, hypertrophic cardiomyopathy, dilated cardiomyopathy, nonalcoholic fatty liver disease, Alzheimer's disease, Parkinson's disease, and Huntington's disease were verified. We further constructed -mediated gene network, in which , , , , and were significantly altered in Tmem43 mice versus Tmem43 controls. Our study defined the importance of for cardiac- and metabolism-related pathways, suggesting that cardiovascular disease-relevant risk factors may also increase risk of metabolic and neurodegenerative diseases via -mediated pathways.