Objective To investigate the expression and function of integrin-iinked kinase (ILK) in the transdifferentiation process of primary tubular epithelial cell( TEC) and its effect on the accumulation of extracellular matrix (ECM) in the aging process. Methods Primary TEC was cultured from kidneys of male Wistar rats aged 3 and 24 months. Then the primary TEC was stimulated by TGF-β at the concentrations of 0, 5, 10 and 20-40/μg/L for 24 h. The TEC expressions of α-SMA,ILK and F-actin were detected by immunocytochemistry or indirect immunofluorescence. FN or ILK protein expression levels were tested by Western-blot. DIG-labelled cRNA probe of rat ILK in situ hybridization was obtained by transcription in vitro, with which ILK expression level and the location of TEC were detected. Results α-SMA expression levels were very low in young or aging rat TEC on the base situation, no significant difference was found between the two groups. However, ILK and F-actin levels in 24 months group were higher than in 3 months group. Along with increasing concentration of TGF-β, α-SMA, ILK and F-actin levels were increased. The expression of ILK was associated with F-actin expression. FN and ILK expression levels were significantly lower in 3 monthsrats TEC than in 24 monthsrats, P0. 05. Conclusions (1)Along with the increased degree of transdifferentiation of primary TEC, the expression level of ILK is up-regulated, which mediates the process of transdifferntiation through regulating the rearrangement of F-actin. (2) ILK and F-actin expression levels increase along with the aging. ILK and FN expressions are up-regulated along with the aging. These suggest that the TEC of aging kidney is prone to transdifferentiation in the state of stress.

Specific anti-hURAT1 rabbit polyclonal antibody was obtained, and both Western-blot and immunohistochemistry showed that hURAT1 was expressed in the human kidney brush border, localized in the apical membrane of the LLC-PK1 cell. hURAT1 protein was a membrane protein located in renal proximal tubule, which could be detected in the apical membrane. The anti-hURAT1 polyclonal antibody could be used for studying the physiological function of hURAT1 and its pathology.