This study by Skurk et al. showed for the first time that adiponectin is differentially expressed in the hearts of patients with dilated cardiomyopathy (DCM) and provided evidence for a local paracrine cardiac adiponectin system that appears to be involved in the pathogenesis of DCM. The authors found that adiponectin and adiponectin receptor are expressed in healthy human hearts and that intramyocardial adiponectin mRNA expression and protein levels are reduced in patients with moderate (n=9) and severe DCM (n=8), independent of tumor necrosis factor-a and serum adiponectin concentrations. Moreover, blockade of adiponectin secretion from cardiomyocyte cultures was accompanied by a strong upregulation of adiponectin expression as well as a moderate increased expression of its receptors, suggesting auto/paracrine adiponectin regulation within the heart. Furthermore, the authors showed that adiponectin improved stress-induced apoptosis of cardiomyocytes by activating the serine threonine kinase Akt. The data suggests the existence of a local cardiac adiponectin system whose regulation is independent of serum adiponectin concentrations and which might play an important role in the pathogenesis of heart failure.
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