BioProject

Genome wide gene expression analysis of mRNA siolated from whole heart tissue from wild type and cardiomyocyte selective MR null mice. More...

Genome wide gene expression analysis of mRNA siolated from whole heart tissue from wild type and cardiomyocyte selective MR null mice. The role of mineralocorticoid receptors (MR) in specific cell types of the myocardium in cardiac remodeling remains unknown. We investigated MR in cardiomyocytes in DOC/salt-induced cardiac pathology. Cardiomyocyte MR-null mice (CM-MRKO) and control mice (WT) were given DOC/salt and cardiac responses were examined at 8 days and 8 weeks. Cardiac function in untreated mice wild type and CM-MRKO mice was determined by Langendorf and showed no differences. At 8 days CM-MRKO showed equivalent monocyte/macrophage recruitment to wild type mice in response to DOC/salt treatment. Profibrotic markers were significantly reduced in CM-MRKO hearts at base line and in response to DOC/salt. In contrast, at 8 weeks CM-MRKO mice showed no DOC/salt-induced increase in inflammatory cell infiltrate, fibrosis or systolic blood pressure (SBP). Similarly, DOC/salt-mediated increases in proinflammatory and profibrotic gene expression were not detected in CM-MRKO mice. Although mRNA levels for fibronectin and collagen III were similar for each genotype, this was not translated into protein expression. Interestingly, untreated CM-MRKO mice showed increased mRNA and protein for decorin and a further increase with DOC/salt. Together, these data suggest a direct role for cardiomyocyte MR in DOC/salt-induced tissue remodelling and SBP regulation. Moreover, a specific profibrotic pathway is dysregulated in CM-MRKO mice, suggesting a potential mechanism for the cardioprotective effects of selective MR deletion in cardiomyocytes. Overall design: Pool mRNA (equal amounts) from whole heart from 8 animals per group. Less...