Inducible conditional vascular-specific overexpression of peroxisome proliferator-activated receptor beta/delta leads to rapid cardiac hypertrophy

Peroxisome proliferator-activated receptors are nuclear receptors which function as ligand-activated transcription factors. among them,peroxisome proliferator-activated receptor beta/delta (pparβ/δ) is highly expressed in the heart and thought to have cardioprotective functions due to its beneficial effects in metabolic syndrome. as we already showed that pparβ/δ activation resulted in an enhanced cardiac angiogenesis and growth without impairment of heart function,we were interested to determine the effects of a specific activation of pparβ/δ in the vasculature on cardiac performance under normal and in chronic ischemic heart disease conditions. we analyzed the effects of a specific pparβ/δ overexpression in endothelial cells on the heart using an inducible conditional vascular-specific mouse model. we demonstrate that vessel-specific overexpression of pparβ/δ induces rapid cardiac angiogenesis and growth with an increase in cardiomyocyte size. upon myocardial infarction,vascular overexpression of pparβ/δ,despite the enhanced cardiac vessel formation,does not protect against chronic ischemic injury. our results suggest that the proper balance of pparβ/δ activation in the different cardiac cell types is required to obtain beneficial effects on the outcome in chronic ischemic heart disease. © 2016 kay-dietrich wagner et al.