Fig. 1.

Cardiac UCP3 levels are decreased in rodent models of obesity, insulin resistance and type 2 diabetes. a Immunoblotting revealed a decrease in UCP3 protein levels in hearts of male ob/ob mice (n = 4) and male db/db mice (n = 4) when compared to wild-type (WT) male C57BL/6J control mice (n = 4). Both ob/ob and db/db mice were hyperglycemic (b) and hyperinsulinemic (c). d db/db mice displayed severe hyperleptinemia, while plasma leptin levels were undetectable in ob/ob mice. e UCP3 protein levels were also decreased in hearts from type 2 diabetic male LoxTB MC4R^−/− mice (n = 3) and male LepR/Nestin-cre mice (n = 3). f Cardiac UCP3 protein levels were similarly decreased in hearts from obese and insulin-resistant MC4RKO rats (n = 5). g The decrease in cardiac UCP3 protein levels in these animals ranged between 20 and 49%. Similar results were obtained when normalizing UCP3 levels to the ubiquitous cellular protein HSP60 or to the mitochondrial protein VDAC. Data are presented as mean ± SE. *p < 0.05 vs. WT animals; ^†p < 0.05 vs. ob/ob mice