MEKK1-MKK4-JNK-AP1 Pathway Negatively Regulates Rgs4 Expression in Colonic Smooth Muscle Cells
Figure 1
The JNK inhibitor SP600125 dose-dependently increases Rgs4 expression in rabbit colonic smooth muscle cells.
Cultured and serum-starved muscle cells were treated with indicated concentration of SP600125 1 h before treatment with IL-1β (10 ng/ml) for 3 h, followed by reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) (A, B) and Western blot analysis (C, D). The relative level of Rgs4 mRNA expression (fold induction) was presented as compared with the control without SP600125 pretreatment after GAPDH normalization (A, B). Levels of β-actin and GAPDH were used as a loading control (C). The relative optical density (fold change) was presented as compared with the vehicle control (DMSO) after β-actin or GAPDH normalization (D). Values are means ± SE of 3 experiments. * (p<0.05) indicates significant increase after IL-1β treatment as compared with the control. + (p<0.05) indicate significant increase by ANOVA and Newman-Keuls comparison of SP600125 treatment with the vehicle control.