DHRS7c, a novel cardiomyocyte-expressed gene that is down-regulated by adrenergic stimulation and in heart failure.

ABSTRACT

AIMS: Although cardiac diseases account for the highest mortality and morbidity rates in Western society, there is still a considerable gap in our knowledge of genes that contribute to cardiac (dys)function. Here we screened for gene expression profiles correlated to heart failure. METHODS AND RESULTS: By expression profiling we identified a novel gene, termed DHRS7c, which was significantly down-regulated by adrenergic stimulation and in heart failure models. Dhrs7c is a short chain dehydrogenase/reductase (SDR) and is localized to the endo/sarcoplasmic reticulum. Dhrs7c is strongly conserved in vertebrates, and mRNA and protein expression levels were highest in heart and skeletal muscle followed by skin, but were not detectable in other organs. In vitro, both α- and ß-adrenergic stimulation repressed Dhrs7c expression in neonatal cardiomyocytes and this could be mimicked by the direct activation of protein kinase C and adenylate cyclase, the respective intracellular targets of these hormones. In contrast, endothelin-1, which also provoked strong hypertrophy development in vitro, did not repress Dhrs7c expression. The latter suggests adrenergic specificity and indicates that down-regulation is not a prerequisite for hypertrophy development. In vivo adrenergic stimulation could also down-regulate Dhrs7c expression. Finally, we confirmed that expression was also down-regulated in two different models of failure and, importantly, also in biopsies from human heart failure patients. CONCLUSION: Our results show that the expression of Dhrs7c, a novel endo/sarcoplasmic reticulum-localized SDR, is inversely correlated with adrenergic stimulation and heart failure development.