In vitro differentiation and mineralization of cartilaginous nodules from enzymatically released rat nasal cartilage cells.
Nasal cartilage cells from 21-day-old rat fetuses were cultured at high density in the presence of ascorbic acid and beta-glycerophosphate over a 12-day period. Immediately after plating, the cells exhibited a fibroblastic morphology, lost their chondrocyte phenotype and expressed type I collagen. On day 3, clusters of enlarged polygonal cells were found. These cell clusters synthetized type II collagen and formed an alcian-blue-positive matrix. The following days, a progressive increase in the number of cells positive for type II collagen was noted and, on day 8, typical cartilaginous nodules were formed. These nodules increased in size and number, spreading outward, laying down a dense matrix which mineralized. Light and electron microscopy observations of cross-sections of nodules confirmed the cartilaginous nature of this tissue formed in vitro with typical chondrocytes embedded in a hyaline matrix. Furthermore, at the electron microscopic level, matrix vesicles were seen in extracellular matrix associated with the initiation of mineralization. Typical rod-like crystals were present in the intercellular spaces along the collagen fibers. These results indicated that in a specific environment, dedifferentiated chondrocytes were able to redifferentiate and to form nodular structures with morphological ultrastructure of calcified cartilage observed in vivo.
Sautier
J M
JM
Laboratoire de Biologie-Odontologie, Institut Biomédical des Cordeliers, Paris, France.
Nefussi
J R
JR
Forest
N
N
D000423:Alcian Blue; D000818:Animals; D002113:Calcification, Physiologic; D002356:Cartilage / Q000166:cytology* / Q000502:physiology* / Q000648:ultrastructure; D002454:Cell Differentiation; D002478:Cells, Cultured; D003094:Collagen / Q000032:analysis; D005109:Extracellular Matrix / Q000648:ultrastructure; D005333:Fetus; D005347:Fibroblasts / Q000166:cytology / Q000648:ultrastructure; D007150:Immunohistochemistry; D008854:Microscopy, Electron; D009666:Nose; D051381:Rats; D017207:Rats, Sprague-Dawley
D003094:Collagen; D000423:Alcian Blue