CTGF/Hcs24, a hypertrophic chondrocyte-specific gene product, stimulates proliferation and differentiation, but not hypertrophy of cultured articular chondrocytes.
We previously reported that connective tissue growth factor/hypertrophic chondrocyte-specific gene product 24 (CTGF/Hcs24) stimulated the proliferation and differentiation of rabbit growth cartilage (RGC) cells in vitro. In this study, we investigated the effects of CTGF/Hcs24 on the proliferation and differentiation of rabbit articular cartilage (RAC) cells in vitro. RAC cells transduced by recombinant adenoviruses generating mRNA for CTGF/Hcs24 synthesized more proteoglycan than the control cells. Also, treatment of RAC cells with recombinant CTGF/Hcs24 (rCTGF/Hcs24) increased DNA and proteoglycan syntheses in a dose-dependent manner. Northern blot analysis revealed that the rCTGF/Hcs24 stimulated the gene expression of type II collagen and aggrecan core protein, which are markers of chondrocyte maturation, in both RGC and RAC cells. However, the gene expression of type X collagen, a marker of hypertrophic chondrocytes, was stimulated by rCTGF/Hcs24 only in RGC cells, but not in RAC cells. Oppositely, gene expression of tenascin-C, a marker of articular chondrocytes, was stimulated by rCTGF/Hcs24 in RAC cells, but not in RGC cells. Moreover, rCTGF/Hcs24 effectively increased both alkaline phosphatase (ALPase) activity and matrix calcification of RGC cells, but not of RAC cells. These results indicate that CTGF/Hcs24 promotes the proliferation and differentiation of articular chondrocytes, but does not promote their hypertrophy or calcification. Taken together, the data show that CTGF/Hcs24 is a direct growth and differentiation factor for articular cartilage, and suggest that it may be useful for the repair of articular cartilage.
Department of Biochemistry and Molecular Dentistry, Okayama University Graduate School of Medicine and Dentistry, Okayama, Japan.
Takashi
T
Nishida
Satoshi
S
Kubota
Tohru
T
Nakanishi
Takuo
T
Kuboki
Gen
G
Yosimichi
Seiji
S
Kondo
Masaharu
M
Takigawa
D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D015415:Biomarkers; D002118:Calcium / Q000378:metabolism; D002358:Cartilage, Articular / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D019902:Chondrocytes / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D055513:Connective Tissue Growth Factor; D004247:DNA / Q000096:biosynthesis; D018014:Gene Transfer Techniques; D006133:Growth Substances / Q000235:genetics / Q000494:pharmacology*; D006984:Hypertrophy; D017874:Immediate-Early Proteins / Q000235:genetics / Q000494:pharmacology*; D036341:Intercellular Signaling Peptides and Proteins; D008934:Mitogens / Q000494:pharmacology*; D011509:Proteoglycans / Q000096:biosynthesis; D012333:RNA, Messenger / Q000378:metabolism; D011817:Rabbits
D015415:Biomarkers; D006133:Growth Substances; D017874:Immediate-Early Proteins; D036341:Intercellular Signaling Peptides and Proteins; D008934:Mitogens; D011509:Proteoglycans; D012333:RNA, Messenger; D055513:Connective Tissue Growth Factor; D004247:DNA; D000469:Alkaline Phosphatase; D002118:Calcium