TGF-β1 induces ILK expression in renal tubular epithelial cells. (a–d) Western blot analyses show that TGF-β1 induced ILK protein expression in a time- and dose-dependent manner. HKC cells were incubated with either the same concentration of TGF-β1 (2 ng/ml) for various periods of time as indicated (a and c) or increasing amounts of TGF-β1 for 24 hours (b and d). Cell lysates were immunoblotted with Ab’s against ILK and actin, respectively. (a and b) Representative Western blots. (c and d) Graphic presentation of relative ILK abundance (fold induction) normalized to actin. Data are presented as mean ± SEM of three independent experiments. (e and f) Immunofluorescence staining shows the localization of ILK in control (e) or TGF-β1–treated HKC cells (f). Arrowheads indicate positive ILK staining. Scale bar: 5 μm.