F. Western blot analysis of phospho-TFEB (S142) and IRS1 in RCS chondrocytes treated with vehicle (5% ABS) and FGF18 (50 ng/mL) for 12h. JNK inhibitor was used at 50 μM for 12h to inhibit kinase activity. β-actin was used as loading control. Representative images of N=3 independent experiments. Bar graphs show quantification of indicated proteins normalized to β-actin. Mean +/- standard error of the mean (sem). Student's paired T-test *p<0.05; NS not significant. 