Role of interleukin-4 receptor in renal fibrosis following renal ischemia-reperfusion injury in mice / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the role of interleukin-4 receptor (IL-4R) in renal fibrosis following renal ischemia-reperfusion (I/R) injury in mice.Methods Twelve male wild type BALB/C mice and 12 IL-4Rα gene-knockout mice,aged 8-10 weeks,weighing 20-30 g,were used in the study.The mice of either type were divided into 2 groups (n =6 each) using a random number tablesham operation group (group S) and group I/R.In group I/R,renal I/R was induced by occlusion of the right renal artery for 1 h with atraumatic microclips followed by 2 weeks of reperfusion.The right renal artery was only isolated in group S.At 2 weeks of reperfusion,blood samples were taken from the orbital vein for determination of the concentrations of serum blood urea nitrogen (BUN) and creatinine (Cr).The renal tissues were obtained,and the renal fibrosis area was measured by Sirius Red staining.The expression of fibronectin (FN),collagen Ⅰ (COL-Ⅰ) and α-smooth muscle actin (α-SMA) in renal tissues was detected by immunofluorescence.The expression of signal transducer and activator of transcription 6 (STAT6) and phospho-STAT6 in renal tissues was determined by Western blot.The ratio of phoshop-STAT6 to STAT6 was calculated to reflect the phosphorylation of STAT6.Results Compared with group S of wild type mice,the serum BUN and Cr concentrations and renal fibrosis area were significantly increased,the expression of FN,COL-Ⅰ and α-SMA in renal tissues was significantly up-regulated,and the phosphorylation of STAT6 in renal tissues was significantly increased in group I/R of wild type and IL-4Rα KO mice (P＜0.05).Compared with group I/R of wild type mice,the serum BUN and Cr concentrations and renal fibrosis area were significantly decreased,the expression of FN,COL-Ⅰ and α-SMA in renal tissues was significantly down-regulated,and the phosphorylation of STAT6 in renal tissues was significantly decreased in group I/R of IL-4RαKO mice (P＜0.05).Conclusion The mechanism of renal fibrosis following renal I/R injury is partially related to IL-4R,and IL-4R results in renal fibrosis through promoting activation of STAT6 signaling pathway in mice.