Association between interleukin-17 expression in renal tissue of rats with diabetic nephropathy and renal tubulointerstitial lesions

Abstract

Objective To investigate the association between the expression of interleukin-17 （ IL-17 ） in renal tissues of rats with diabetic nephropathy and tubulointerstitial lesions. Methods Ninety rats were randomly divided into three groups： control group, type 1 diabetic mellitus （T1DM） group, and type 2 diabetic mellitus （T2DM） group. The rats in T1DM group were given 50 mg/kg streptozotiein （STZ） , and those in T2DM group fed on a diet enriched with sucrose, triglyceride and cholesterol, and in- jected with 25 mg/kg STZ. At 2nd and 4th week, serum and urine IL-17 levels were determined by using enzyme-linked immunosorbent assay （ELISA）. The expression of IL-17 and transforming growth factor-131 （ TGF-B1 ） in the kidney was detected by using immunohistoehemisty staining and Western blotting. Results Serum and urine IL-17 levels were obviously increase in diabetic rats. The expression of IL-17 was detectable in renal tubulointerstitium of diabetic rats. The expression of IL-17 in T2DM and T1DM groups was 0. 1809 ±0. 0090 and O. 2357 ±0. 0410 respectively （P 〈0. 05）. The expression of TGF-B1 in T2DM and T1DM groups was 0. 2809 ± 0. 0420 and 0. 1412 ± 0. 0610 respectively （ P 〈 0.05 ）. The expression of IL-17 in renal tubulointerstitium of diabetic rats was positively correlated with urine IL-17 （r = 0. 715 ,P 〈 0. 05 ）. Conclusion The increase of IL-17 expression may play an important role in diabetes mellitus-in- dueed tubulointerstitial lesions. IL-17 and TGF-[31 might exert different effects on pathogenesis and pro- gression of diabetic nephropathy from T1DM and T2DM. Key words: Interleukin-17; Diabetes mellitus; Transforming growth faetor-B1