LPAR6 and obesity due to melanocortin 4 receptor deficiency: Taken together, these data suggest that all six, so far identified, LPA receptors are expressed in the murine heart and cardiomyocytes and that diet-induced obesity and acute changes in nutritional status (feeding/fasting) lead to altered expression of distinct LPA receptors, notably an increase in LPA4, LPA5, and/or LPA6, in the myocardium and cardiomyocytes.