title: Growth/differentiation factor 5 enhances chondrocyte maturation.
abstract: Growth/differentiation factor 5 (GDF5) is required for limb mesenchymal cell condensation and joint formation during skeletogenesis. Here, we use a model consisting of long-term, high-density cultures of chick embryonic limb mesenchymal cells, which undergo the entire life history of chondrocyte development, to examine the effects of GDF5 overexpression on chondrocyte maturation. Exposure to GDF5 significantly enhanced chondrocyte hypertrophy and maturation, as determined by the presence of alkaline phosphatase activity, collagen type X protein production, and the presence of a sulfated proteoglycan-rich extracellular matrix. Histologic analysis also revealed an increase in cell volume and cellular encasement in larger lacunae in GDF5-treated cultures. Taken together, these results support a role for GDF5 in influencing chondrocyte maturation and the induction of hypertrophy in the late stages of embryonic cartilage development, and provide additional mechanistic insights into the role of GDF5 in skeletal development.
mesh_terms: D000469:Alkaline Phosphatase / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D019485:Bone Morphogenetic Proteins / Q000378:metabolism / Q000494:pharmacology* / Q000502:physiology; D002356:Cartilage / Q000187:drug effects / Q000648:ultrastructure; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D002642:Chick Embryo; D019902:Chondrocytes / Q000166:cytology* / Q000648:ultrastructure; D020219:Chondrogenesis; D024121:Collagen Type X / Q000096:biosynthesis; D005109:Extracellular Matrix / Q000378:metabolism; D005121:Extremities / Q000196:embryology* / Q000502:physiology; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D055428:Growth Differentiation Factor 5; D006984:Hypertrophy; D008648:Mesoderm; D011509:Proteoglycans / Q000378:metabolism; D013431:Sulfates / Q000378:metabolism; D013997:Time Factors
chemical_list: D019485:Bone Morphogenetic Proteins; D024121:Collagen Type X; D055428:Growth Differentiation Factor 5; D011509:Proteoglycans; D013431:Sulfates; D000469:Alkaline Phosphatase