Peroxisome Proliferator-Activated Receptor γ1 Expression in Porcine White Blood Cells: Dynamic Regulation with Acute Endotoxemia

Peroxisome proliferator-activated receptor γ (PPARγ), a primary regulator of adipocyte differentiation, has been implicated in the regulation of monocyte and macrophage function in vitro. We report that PPARγ protein is expressed in porcine peripheral white blood cells (WBC), and that PPARγ1 but not γ2 mRNA predominates. Additionally, we provide the first evidence that in vivo lipopolysaccharide challenge (LPS, 25 μg/kg BW) causes a dynamic increase in PPARγ protein expression in peripheral WBC (P < 0.05). PPARγ expression was increased 2-fold over basal (1 hr post-LPS), was maximal by 4 hr (3-fold), and was normalized to control by 8 hr post-LPS. Changes in PPARγ expression coincided with or closely followed LPS-induced changes in plasma cortisol, TNF-α, insulin, IGF-1, glucose, and free fatty acids. These data suggest that induction of PPARγ expression in WBC may play a role in host response to acute inflammatory challenge and may prove to be an important target of anti-inflammatory therapies.