Objective: To explore the expression and role of integrin-linking kinase (ILK) in aging rats subjected to unilateral ureteral obstruction (UUO).
Methods: The UUO model and sham-operated rats (SHAM) were established with 3-month-old rats and 26-month-old rats and the rats were sacrificed before UUO and after UUO at 3, 7 and 14 days. Immunofluorescent staining, Western blot, RT-PCR, etc were applied to detect the expressions of ILK and fibronectin (FN) in the renal of UUO rat at each time point.
Results: With the time of UUO, the relative interstitial areas and tubulointerstitial fibrotic areas in 26-month-old rats were significantly higher than those in 3-month-old ones at each time point (P < 0.01) and the mRNA and protein levels of ILK and FN are increasing with the time of UUO in both groups (P < 0.01). ILK mRNA semi-quantitative values of 26-month and 3-month rats were 0.98 +/- 0.06 vs 0.72 +/- 0.06, 3 days after UUO (P < 0.01), 1.49 +/- 0.05 vs 1.03 +/- 0.04, 14 days after UUO (P < 0.01), respectively. ILK proteinsemi-quantitative values of 26-month and 3-month rats were 0.57 +/- 0.04 vs 0.52 +/- 0.03, 3 days after UUO (P < 0.01), 0.76 +/- 0.04 vs 0.63 +/- 0.03, 14 days after UUO (P < 0.01), respectively. The expressions of ILK mRNA and protein level were positively correlated with the relatively renal interstitial areas (r = 0.71, P < 0.05 and r = 0.80, P < 0.05, respectively). And the whole levels of ILK and FN in 26-month-old rats are higher than those of 3-month-old rats.
Conclusion: With aging, the expressions of ILK and FN increase progressively in UUO rat, and the over-expression of ILK probably promotes renal tubulointerstitial fibrosis and aging.