Fig. 8.

Effects of inhibition of TGase-1, phosphoinositide 3-kinase (PI3K)/AKT, or STAT3 on GSK-3β phosphorylation following oxidant injury. Serum-starved RPTC were pretreated with 100 μM MDC (A) and 20 μM LY294002 (C) for 1 h and then treated with 1 mM H₂O₂ for 30 min. RPTC were transfected with scrambled siRNA or TGase-1 siRNA (B) or STAT3 siRNA (D), starved for 24 h, and then exposed to 1 mM H₂O₂ for 30 min. Cell lysates were subjected to immunoblot analysis using antibodies against p-Ser9-GSK-3β, GSK-3β, or actin. Representative immunoblots from 3 experiments are shown.