Spontaneous differentiating primary chondrocytic tissue culture: a model for endochondral ossification.
Primary cartilage-derived cell cultures tend to undergo dedifferentiation, acquire fibroblastic features, and lose most of the characteristics of mature chondrocytes. This phenomenon is due mainly to the close matrix-cell interrelationship typical of cartilage tissue, which is vital for the preservation of the cartilaginous features. In this study we present a model for spontaneous redifferentiation of primary chondrocytic culture. Mandibular condyles excised from 3-day-old mice, thoroughly cleaned of all soft tissue, were digested with 0.1% collagenase. These mandibular condyle-derived chondrocytes (MCDC) were cultured under chondrogenesis-supporting conditions; that is, 5 x 10(5) cells/mL were incubated in Dulbecco's modified Eagle medium supplemented with 100 microg/mL ascorbic acid, 1 mmol/L calcium chloride, 10 mmol/L beta-glycerophosphate, 10% fetal calf serum, and antibiotics. Development and growth rates of these cartilage-derived cultures were determined by following morphological and functional changes. MCDC proliferated intensively during the first 24-48 h following plating, showing fibroblast-like (long spindle-shaped) morphology and producing mainly type I collagen. The proliferation rate gradually declined, and the cells developed polygonal shapes and started to produce type II collagen. In the 10-14-day-old cultures, cells began to aggregate in cartilaginous nodules and exhibited positive staining for acidic Alcian blue, type X collagen, and von Kossa. Expression of core-binding factor alpha(1) increased between 3 and 5 days and declined gradually thereafter. The condylar-derived tissue culture presented here depicts a spontaneous redifferentiation chondrocytic tissue culture that exhibits features of mature chondrocytes typically found in skeletal growth centers. The present study offers a model for primary chondrocytic tissue culture, which might serve as a model for in vitro endochondral ossification.
Reiter
I
I
Department of Anatomy and Cell Biology, Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel.
Tzukerman
M
M
Maor
G
G
D000818:Animals; D002454:Cell Differentiation / Q000502:physiology; D002478:Cells, Cultured; D019902:Chondrocytes / Q000166:cytology* / Q000502:physiology; D050660:Core Binding Factors; D046508:Culture Techniques / Q000379:methods; D008335:Mandibular Condyle / Q000166:cytology / Q000502:physiology; D051379:Mice; D008813:Mice, Inbred ICR; D009363:Neoplasm Proteins; D010012:Osteogenesis / Q000502:physiology*; D017526:Receptor, IGF Type 1 / Q000096:biosynthesis; D014157:Transcription Factors / Q000096:biosynthesis
D050660:Core Binding Factors; D009363:Neoplasm Proteins; D014157:Transcription Factors; D017526:Receptor, IGF Type 1