Background
'Healthy' aging drives structural and functional changes in the heart including maladaptive electrical remodeling, fibrosis and inflammation, which lower the threshold for cardiovascular diseases such as heart failure (HF) and atrial fibrillation (AF). Despite mixed
Conclusion
These data support the hypothesis that relaxin alters gene transcription and suppresses inflammatory pathways and genes associated with HF and aging. Relaxin's suppression of inflammation and fibrosis supports its potential as a therapy for cardiovascular and inflammation-related diseases, such as HF, AF and diabetes.
Results
Young (9-month) and aged (24-month), male and female F-344/Brown Norway rats were treated with relaxin (0.4 mg/kg/day) for 2-weeks delivered by subcutaneous osmotic mini-pumps or with sodium acetate (controls). The genomic effects of aging and relaxin were evaluated by extracting RNA from the left ventricles and analyzing genomic changes by RNA-sequencing, Ingenuity Pathway Analysis, MetaCore and tissue immunohistochemistry. We found that aging promotes a native inflammatory response with distinct sex-differences and relaxin suppresses transcription of multiple genes and signaling pathways associated with inflammation and HF in both genders. In addition, aging significantly increased: macrophage infiltration and atrial natriuretic peptide levels in female ventricles, and activation of the complement cascade, whereas relaxin reversed these age-related effects.