NR3C1 and obesity due to melanocortin 4 receptor deficiency: In addition, PGC1a (Peroxisome proliferator-activated receptor gamma coactivator 1-alpha) mRNA and protein expression as well as GR binding to PGC1a promoter were also found to be reduced in HFD mice, suggesting that the hepatic GR may be a regulator of PGC1a expression, and both could be involved in obesity-induced mitochondrial dysfunction through regulating mtDNA expression.