Fig. 6. ß-Catenin function as a nuclear signaling molecule is sufficient to cause phenotype loss of chondrocytes. (A) Chondrocytes were treated with vehicle alone as a control, 1 µM RA or 5 ng/ml IL1ß for 72 hours. The distribution of ß-catenin was determined by immunofluorescence microscopy. (B) Chondrocytes were transfected with active (TOPFlash) or inactive (FOPFlash) TCF/LEF reporter gene for ß-catenin and treated with vehicle alone as a control (Con), RA, or IL1ß, and TCF/LEF reporter activity was monitored (upper panel). ß-Catenin protein in nuclear preparation or Jun and connexin 43 (Cx43) in whole cell lysates were detected by western blotting from chondrocytes treated with RA or IL1ß.