The expression and signification of kidney injury molecule-1 on renal ischemia reperfusion injury in rat

Objective To observe the expression levels of kidney injury molecule-1(KIM-1) in renal tissues of ischemia-reperfusion rats, and to explore the value in the diagnosis of acute kidney injury. Methods Rats were randomly divided into two groups, control(CON) group (n=64) and acute kidney ischemia reperfusion injury (AIKI) group (n=64). Rats were sacrificed following reperfusion 2 h, 6 h, 24 h, 48 h, 72 h, 1 week (w), 2 w, and 4 w. The changes of morphology were checked on HE staining sections under light microscope.The extent of tubulointerstitial injury was determined by Sayhan classification.The distribution and expression of KIM-1 in renal tissue were observed by immunohistochemistry and Western blotting.Serum samples were collected and serum creatinine measurement was performed at different reperfusion time points. Results (1) Compared with the CON group, the renal tubulointerstitial injury scores of AIKI group were significantly higher at all times after reperfusion (P<0.01). (2) The expression of KIM-1 was consistent with the tubulointerstitial injury.The positive correlation between KIM-1 and the tubulointerstitial injury scores was significant(r=0.887, P=0.003). (3) Compared with the CON group, serum creatinine in AIKI group was significant higher at 2 h, 6 h, 24 h, 48 h, 72 h after reperfusion (P<0.05). Serum creatinine had no correlation with the damage of renal tubulointerstitial. Conclusion The expression of KIM-1 increases significantly in renal ischemia reperfusion injury, and it is consistent with the tubulointerstitial injury.Compared with serum creatinine, KIM-1 may be a more accurate biomarker of renal damage. Key words: Kidney injury molecule-1; Acute ischemia reperfusion kidney injury; Kidney tubulointerstitial injury; Acute kidney injury