Integrative analysis of multiomics data identifies selenium-related gene ALAD associating with keshan disease

Keshan disease is an endemic fatal dilated cardiomyopathy that can cause heart enlargement, heart failure, and cardiogenic death. Selenium deficiency is considered to be the main cause of Keshan disease. However, the molecular mechanism underlying Keshan disease remains unclear. Our whole-exome sequencing from 68 patients with Keshan disease and 100 controls found 199 candidate genes by gene-level burden tests. Interestingly, using multiomics data, the selenium-related gene ALAD (δ-aminolevulinic acid dehydratase) was the only candidate causative gene identified by three different analysis approaches. Based on single-cell transcriptome data, ALAD was highly expressed in cardiomyocytes and double mutations of human ALAD dramatically reduced its enzyme activity in vitro compared to negative control. Functional analysis of ALAD inhibition in mice resulted in a Keshan phenotype with left ventricular enlargement and cardiac dysfunction, whereas administration of sodium selenite markedly reversed the changes caused by ALAD inhibition. In addition, sodium selenite reversed Keshan phenotypes by affecting energy metabolism and mitochondrial function in mice as shown by the transcriptomic and proteomic data and the ultrastructure of cardiac myocytes. Our findings are the first to demonstrate that the selenium-related gene ALAD is essential for cardiac function by maintaining normal mitochondrial activity, providing strong molecular evidence supporting the hypothesis of selenium deficiency in Keshan disease. These results identified ALAD as a novel target for therapeutic intervention in Keshan disease and Keshan disease-related dilated cardiomyopathy. Blood samples were collected and analyzed with whole-exome sequencing from 68 patients with Keshan disease and 100 healthy individuals, and the selenium-related gene ALAD is the only candidate pathogenic gene identified by three different analysis approaches. The inhibition of ALAD in mice promoted left ventricular enlargement and cardiac dysfunction, but the addition of sodium selenite remarkably reserved the changes caused by inhibition of ALAD. Our data showed that a large number of proteins associated with energy metabolism were upregulated and mitochondrial function was impaired by ALAD inhibition, while widespread upregulated proteins were returned to normal expression with the addition of sodium selenite. [Display omitted] •Selenium-related gene ALAD is a novel target for therapeutic intervention in Keshan diseas