Peroxisome Proliferator-Activated Receptors Alpha, Beta, and Gamma mRNA and Protein Expression in Human Fetal Tissues

Abstract

Peroxisome proliferator-activated receptors (PPARs) regulate lipid and glucose homeostasis, are targets of pharmaceuticals, and are also activated by environmental contaminants. Almost nothing is known about expression of PPARs during human fetal development. This study examines expression of PPAR, , and mRNA and protein in human fetal tissues. With increasing fetal age, mRNA expression of PPAR and increased in liver, but PPAR decreased in heart and intestine, and PPAR decreased in adrenal. Adult and fetal mean expression of PPAR, , and mRNA did not differ in intestine, but expression was lower in fetal stomach and heart. PPAR and mRNA in kidney and spleen, and PPAR mRNA in lung and adrenal were lower in fetal versus adult. PPAR in liver and PPAR mRNA in thymus were higher in fetal versus adult. PPAR protein increased with fetal age in intestine and decreased in lung, kidney, and adrenal. PPAR protein in adrenal and PPAR in kidney decreased with fetal age. This study provides new information on expression of PPAR subtypes during human development and will be important in evaluating the potential for the developing human to respond to PPAR environmental or pharmaceutical agonists.