Fig. 6

Prg4 induction by Wnt/β-catenin signaling via CREB1. a Luciferase activity of ATDC5 cells transfected with one of three different reporter vectors containing proximal regions around the transcription start site of Prg4, and co-transfected with constitutively active Lef1 (Lef1-CA) or GFP control. RLA, relative luciferase activity. *P < 0.05 (Student’s unpaired two-tailed t test). b mRNA and protein levels of CREB1 in SFZ cells loaded with cyclic tensile strain. *P < 0.05 versus 0 h (one-way ANOVA followed by Tukey’s correction). c mRNA levels of CREB1 and Prg4 and protein levels of Ctnnb1, CREB1, and phosphorylated CREB1 (pCREB1) in SFZ cells loaded with fluid flow shear stress (FFSS). *P < 0.05 and **P < 0.01 versus 0 h (one-way ANOVA followed by Tukey’s correction). d mRNA levels of CREB1 and protein levels of CREB1 and pCREB1 in SFZ cells treated with CHIR9021 for 48 h. *P < 0.05 and **P < 0.01 versus (one-way ANOVA followed by Tukey’s correction). e mRNA levels of CREB1 and Prg4 in SFZ cells after 8-h FFSS loading with or without 15 μM FH535 treatment. FH535 was added to the medium at 2 h before FFSS loading. *P < 0.05 and **P < 0.01 versus 0 h (one-way ANOVA followed by Tukey’s correction). f mRNA level of Prg4 in SFZ treated with or without 2 μM CHIR99021 and 100 nM 666-15 for 12 h. *P < 0.05 and **P < 0.01 versus 0 h (one-way ANOVA followed by Tukey’s correction). All data are expressed as mean ± SD of three biologically independent samples per group