OBJECTIVETo investigate the role of human Wnt7b gene in rat chondrocyte degeneration.

METHODSWnt7b gene obtained by PCR was cloned to PCDH-GFP. 293ft cell line was transfected with PCDH-GFP and PCDH-Wnt7b, and the supernatant and transfected cells were collected. The expression level of Wnt7b in 293ft cells was detected by Western blotting. The first passage of chondrocytes were isolated from articular cartilages of newborn born (within 24 h) SD rats were cultured in the supernatants from the transfected cells (at 10- and 50-fold dilutions). The cell morphology of the rat chondrocytes was observed under inverted microscope, and the protein expressions of MMP13, MMP3 and type II collagen and mRNA expressions of A-can, ADAMTS5, Col X and Sox9 were examined by Western blotting or real-time PCR.

RESULTSHuman Wnt7b gene cloned to PCDH-GFP was expressed efficiently in 293ft cell line. Rat chndrocytes cultured for 24 h in the supernatants from PCDH-Wnt7b-transfected 293ft cells underwent changes from a polygonal to a spindle-shaped morphology. The protein expression levels of MMP13 and MMP3 increased while type II collagen decreased significantly, and the mRNA levels of A-can and Sox9 were down-regulated while Col X and ADMATS5 up-regulated in ratchondrocytes after incubation in supernatants from PCDH-Wnt7b-transfected 293ft cells.

CONCLUSIONHuman Wnt7b gene can be expressed efficiently in 293ft cell line and can induce rat chondrocyte degeneration in vitro.