MR blockade with eplerenone prevented obesity-related changes in gene expression, reducing proinflammatory factors and increasing adiponectin in adipose and heart tissue of obese, diabetic mice.
Does eplerenone improve adipokine profiles and reduce inflammation in adipose and heart tissue of obese, diabetic mice?
MR blockade with eplerenone reverses obesity-related proinflammatory adipokine changes and increases adiponectin expression in adipose and heart tissue, suggesting a novel cardioprotective mechanism.
BACKGROUND: In obesity, decreases in adiponectin and increases in proinflammatory adipokines are associated with heart disease. Because adipocytes express mineralocorticoid receptor (MR) and MR blockade reduces cardiovascular inflammation and injury, we tested the hypothesis that MR blockade reduces inflammation and expression of proinflammatory cytokines in adipose tissue and increases adiponectin expression in adipose tissue and hearts of obese mice. METHODS AND RESULTS: We determined the effect of MR blockade (eplerenone, 100 mg/kg per day for 16 weeks) on gene expression in retroperitoneal adipose and heart tissue from obese, diabetic db/db mice (n=8) compared with untreated obese, diabetic db/db mice (n=10) and lean, nondiabetic db/+ littermates (n=11). Expression of tumor necrosis factor-alpha, monocyte chemoattractant protein-1, plasminogen activator inhibitor type 1, and macrophage protein CD68 increased, and expression of adiponectin and peroxisome proliferator-activated receptor-gamma decreased in retroperitoneal adipose tissue from obese versus lean mice. In addition, adiponectin expression in heart was reduced in obese versus lean mice. MR blockade prevented these obesity-related changes in gene expression. Furthermore, treatment of undifferentiated preadipocytes with aldosterone (10(-8) mol/L for 24 hours) increased mRNA levels of tumor necrosis factor-alpha and monocyte chemoattractant protein-1 and reduced mRNA and protein levels of peroxisome proliferator-activated receptor-gamma and adiponectin, supporting a direct aldosterone effect on gene expression. CONCLUSIONS: MR blockade reduced expression of proinflammatory and prothrombotic factors in adipose tissue and increased expression of adiponectin in heart and adipose tissue of obese, diabetic mice. These effects on adiponectin and adipokine gene expression may represent a novel mechanism for the cardioprotective effects of MR blockade.
Guo et al. (2008) studied Obesity and diabetes (n=29). MR blockade (eplerenone) vs. Untreated obese, diabetic db/db mice and lean, nondiabetic db/+ littermates was evaluated on Gene expression in retroperitoneal adipose and heart tissue. MR blockade with eplerenone prevented obesity-related changes in gene expression, reducing proinflammatory factors and increasing adiponectin in adipose and heart tissue of obese, diabetic mice.