Figure 10
Recombinant OPN stimulates ERK signaling in primary mesangial cells.
(A) Immunoblot for phosphorylated ERK and total ERK. Primary mesangial cells were incubated with rmOPN (0 ng/ml, 300 ng/mL) for up to 30 min. Bar graph shows quantification of phosphorylated ERK and total ERK expression. (B) Immunoblot for phosphorylated ERK and total ERK following pre-treatment with an ERK inhibitor. Primary mesangial cells were grown in culture and pre-incubated with an inhibitor of ERK (PD98059; 20 μmol/L) for 30 min followed by treatment with rmOPN for 30 min. Bar graph shows quantification of phosphorylated ERK and total ERK expression. (C) Immunoblot for LOX-1. Primary mesangial cells were pre-incubated with an inhibitor of ERK (PD98059; 20 μmol/L) for 30 min followed by treatment with rmOPN for 48 h. Bar graph shows quantification of LOX-1 protein expression. RmOPN induced LOX-1 protein expression in primary mesangial cells. Data are means ± SEM; n = 3 in each group. Difference between two groups was evaluated by Student’s t-test for unpaired variables and differences among three and four groups were analyzed by one-way ANOVA and subsequent Tukey’s test. *P < 0.05; **P < 0.01.
