ISSN:
1435-5604
Keywords:
Meckel's cartilage
;
chondrocyte
;
calcification
;
transdifferentiation
;
osteocyte
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract We examined the influence of cell density on the phenotypic conversion of Meckel's cartilage cells. The cells were isolated by enzymatic digestion and plated at a density of 0.5 × 104 or 2 × 104 cells/penicylinder and cultured under 5% CO2 in air for up to 4 weeks. The cultures were analyzed histologically by electron microscopy, histochemistry, and immunostaining. At the early stage of high-density culture, metachromatic chondrocytes appeared concomitantly with cartilage-specific type II collagen synthesis. The cells gradually transformed from large polygonal cells to multilayered small round cells, and formed nodules. During the later stage of culture, the cells exhibiting alkaline phosphatase (ALPase) activity, type I collagen, and osteocalcin as bone-type marker proteins consisted of spindle-shaped cells showing phenotypic conversion into osteocyte-like cells in the calcified nodules. In contrast, during low-density culture, most of the cells changed from fibroblastic cells to large flattened cells without cellular nodule formation, but these cells lacked chondrocytic features. Only solitary cells exhibited chondrocyte-specific features such as metachromasia, proteoglycan synthesis, and matrix calcification, but they did not undergo osteocytic transdifferentiation. These results indicate that well-organized nodule-forming cellular and extracellular components in high-density culture stimulate transdifferentiation into osteocyte-like cells.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01763820
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