Resveratrol improves renal inflammatory injury in exhaustive exercise rats by regulating NOD-like receptor protein 3 inflammasome

Abstract

Objective To explore the ameliorative effects of resveratrol on renal inflammation in rats after exhaustive exercise by regulating NOD-like receptor protein 3 (NLRP3) inflammasome. Methods Thirty-six male SD rats were randomly divided into 4 groups: control group (Con, n=8), resveratrol group (Rsv, n=8), exhaustive exercise group (Ex, n=10), and exhaustive exercise+resveratrol group (Ex+Rsv, n=10), and the rats in the Ex and Ex+Rsv groups underwent 4 weeks of exhaustive treadmill exercise. The Rsv and Ex+Rsv groups were given resveratrol intragastrically at a dose of 50 mg/kg per day. The serum and urine samples as well as renal tissues of rats were collected in 24 h after the last training. The serum creatinine (Scr) and blood urea nitrogen (BUN) levels were detected by automatic analyzer; ELISA was used to determine the urine neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1) and the contents of IL-1β, IL-18, TNF-α and IL-6 in renal tissues; The protein expression of NLRP3, apoptosis-associated speck-like protein (ASC), cleaved caspase-1, IL-1β and IL-18 were measured by Western blotting. In addition, the morphological and structural changes of renal tissue were observed with HE staining, and immunofluorescence staining was also performed to observe the co-localization of NLRP3 and ASC. Results The levels of Scr, BUN, NGAL and KIM-1 were significantly higer in the Ex group than the Con group (P < 0.01). HE staining showed that renal injury was observed in the rats of Ex group, and the protein expression levels of NLRP3, ASC, cleaved caspase-1, IL-1β and IL-18 were all remarkably increased (P < 0.01). However, resveratrol supplementation notably down-regulated the protein expression of NLRP3 inflammasome (P < 0.05) and reduced the contents of inflammatory factors in renal tissues (P < 0.05), and ameliorated pathological changes of renal tissues. Conclusions Resveratrol can effectively alleviate the inflammatory damage of renal tissue in rats after exhaustive exercise, and its mechanism may be related to its inhibiting NLRP3 inflammasome overactivation.

Keywords

• resveratrol
• nlrp3 inflammasome
• exhaustive exercise
• inflammatory response