Transcription Factor CHF1/Hey2 Regulates Specific Gene Sets in Serum Stimulated Primary Cardiac Myocytes. Mus musculus

Background: We have previously found that overexpression of CHF1/Hey2 in the myocardium prevents the development of phenylephrine-induced hypertrophy and promotes physiological hypertrophy in an aortic banding model. To identify transcriptional pathways regulated by CHF1/Hey2 in hypertrophy, we cultured primary neonatal mouse cardiac myocytes from wild type and transgenic mice overexpressing CHF1/Hey2 and treated them with serum, a potent hypertrophic stimulus. We determined transcriptional profiles by hybridization to Affymetrix GeneChip® Mouse Gene 1.0 ST Arrays. We identified important biological processes regulated by CHF1/Hey2 by Gene Set Analysis using Biological Process Gene Sets from the Gene Ontology Consortium. Results: We found that overexpression of CHF1/Hey2 suppresses gene sets involved in water transport, regulation of adenylate cyclase activity, embryonic eye morphogenesis, gut development and fluid transport after serum stimulation. Genes involved in protein dephosphorylation, in contrast, demonstrate increased expression in myocytes overexpressing CHF1/Hey2, and this increase is independent of serum treatment. Genes overexpressed prior to serum treatment are involved in regulation of transcription factor activity, protein export from the nucleus, and steroid hormone receptor signaling. Genes overexpressed after serum treatment are involved in autophagy, apoptosis and mitochondrial biogenesis. Conclusions: CHF1/Hey2 suppresses fluid transport, activation of adenylate cyclase activity, promotes phosphatase activity, autophagy and regulates other important biological processes likely relevant to hypertrophy. Overall design: Transgenic Mice and Neonatal Mouse Myocyte Culture: WT no serum, 5; WT with serum, 7; TG no serum, 6; TG with serum, 7.