DGAT1 and obesity due to melanocortin 4 receptor deficiency: However, the mRNA expression of diacylglycerol acyltransferase (DGAT) and PPARα was reduced in fat-fed Mttpflox/floxMck-Cre+/o mice compared with the fat-fed Mttpflox/flox mice (Fig. 3D), supporting the notion that rates of lipoprotein secretion may modulate cardiac triglyceride homeostasis in the setting of diet-induced obesity.