Up-regulation of intermedin protects kidney from ischemia/reperfuston injury / 中华肾脏病杂志

ABSTRACT

Objective To investigate the effect of intermedin (IMD) on renal ischemia/ reperfusion (I/R) injury after the up-regulation of IMD. Methods A total of 24 healthy Wistar male rats were randomly divided into four groups,sham-operated group,I/R group,IMD gene transfection +I/R group and empty plamid +I/R group.All the animals were killed at the end of 24 h of reperfusion.Histological changes and renal function were estimated.The expression and site of IMD were determined by Immunohistochemistry method,semi-quantitative RT-PCR and Western blotting.The protein expressions of endothelin 1 (ET-1),tumor necrosis factor αt (TNF-α) were detected by Western blotting. Results Compared with sham-operated group,tubulointerstitial pathological injury was significant aggravated in I/R group (7.6±2.3) and empty plamid +I/R group (7.0±1.8),and such injury was improved in IMD+I/R group (1.5±0.8) (P＜0.05).Compared with I/R group and empty plamid +I/R group,the renal dysfunction of IMD +I/R group was obviously lessened [BUN(7.73±1.03) mmol/L vs (10.13±2.14) mmol/L,(9.77±1.92) mmol/L; Scr(58.50±3.27) μmol/L vs (80.33±7.15) μmol/L, (75.67±7.58) μmol/L,all P＜0.05].IMD expression was weak in the plasma of tubulointerstitial cells in sham-operated group,and was up-regulated in I/R group. Compared with I/R group, immunohistochemical IMD expression increased obviously (262.03±67.89 vs 175.57±48.06,P＜0.01).The mRNA expression of IMD in IMD+I/R group was up-regulated significantly by 60.7％,66.1％ and the protein expression of IMD in IMD+I/R group increased significantly by 51.4％,55.9％ as compared to I/R and empty plasmid +I/R group.Meanwhile,the protein expressions of ET-1 and TNF-αt in IMD+I/R group were obviously lower compared with those in I/R group (ET-10.08±0.02 vs 0.17±0.02; TNF-α0.21±0.04 vs 0.35± 0.02,all P＜0.05). Conclusion IMD gene transfected into kidneys of rats prior to I/R surgery can attenuate the over-expressions of both ET-1 and TNF-o in I/R injured rat kidneys as well as the damages to the structure and function of the kidneys.