Agonist of peroxisome proliferator-activated receptor-γ, rosiglitazone, reduces renal injury and dysfunction in a murine sepsis model

Background. Agonists of the peroxisome proliferator-activated receptor-gamma may help to regulate inflammation by modulating the production of inflammatory mediators and adhesion molecules. The purpose of this study was to determine the protective effects of rosiglitazone on renal injury in a sepsis model and to explore the mechanism. Methods. In lipopolysaccharide (LPS)-induced mouse sepsis, we examined the effect of rosiglitazone on LPS-induced overproduction of inflammatory mediators, on the expression of adhesion molecules in renal tubular epithelial cells and on renal function. The mechanism of the protective effect was investigated in vitro using human renal tubular epithelial cells. Results. Rosiglitazone significantly decreased serum tumour necrosis factor (TNF)-alpha and interleukin (IL)-1 beta levels during sepsis. The levels of blood urea nitrogen and creatinine were significantly lower in mice pre-treated with rosiglitazone than that in LPS-treated mice. Rosiglitazone reduced the expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in tubular epithelial cells and interstitium of LPS-treated mice. Pre-treatment with rosiglitazone reduced the infiltration of macrophages/monocytes in renal tissue. In cultured tubular epithelia] cells, rosiglitazone significantly decreased the expression of ICAM-I and VCAM-1 induced by TNF-alpha or IL- 1 beta, inhibited the degradation of inhibitor kappa B alpha (I kappa B alpha) and blocked the activation of the p65 subunit of nuclear factor (NF)-kappa B. Conclusions. These results indicate that pre-treatment with rosiglitazone attenuated the production of TNF-alpha and IL-1 beta and reduced adhesion molecule expression in renal tubular epithelial cells of LPS-treated mice. Rosiglitazone has an anti-inflammatory effect in renal tubular epithelial cells through the inhibition of NF-kappa B activation.