Figure 7.

Inhibition of TGF-β-, angiotensin II-, high glucose-, and albumin-induced ER stress by losartan, which were blocked by sirtinol. Proximal tubular cells were incubated with (tumor growth factor-β) TGF-β (10 ng/mL), angiotensin II (AgII, 1 µM), high glucose (glu, 30 mM), and albumin (alb, 5 mg/mL) for three days and then treated with or without losartan (losar, 10 µM) and sirtinol (SIRT1 inhibitor, 10 µM) for two days. Expression of GRP78 and p-eIF2α was examined by Western blot analysis. The relative densities of the bands for GRP78 and p-eIF2α were normalized to those for actin for standardization. Representative blots and quantitative analysis from three independent experiments were shown. Results were expressed as n-fold increase over control as mean ± S.E. #: p < 0.05 vs. con (control); ##: p < 0.05 vs. TGF-β; AgII, glu or alb; ###: p < 0.05 vs. TGF-β + losar, AgII + losar, glu + losar, or alb + losar.