scholarly journals Microfilament modification by dihydrocytochalasin B causes retinoic acid-modulated chondrocytes to reexpress the differentiated collagen phenotype without a change in shape.

1988 ◽  
Vol 106 (1) ◽  
pp. 161-170 ◽  
Author(s):  
P D Benya ◽  
P D Brown ◽  
S R Padilla
Keyword(s):  
Retinoic Acid ◽  
Cell Shape ◽  
Articular Chondrocytes ◽  
Type Ii Collagen ◽  
Phenotypic Change ◽  
Type Iii Collagen ◽  
Type I ◽  
Type Ii ◽  
The Stability ◽  
Rabbit Articular Chondrocytes

Primary monolayers of rabbit articular chondrocytes synthesize high levels of type II collagen and proteoglycan. This capacity was used as a marker for the expression of the differentiated phenotype. Such cells were treated with 1 microgram/ml retinoic acid (RA) for 10 d to produce a modulated collagen phenotype devoid of type II and consisting of predominantly type I trimer and type III collagen. After transfer to secondary culture in the presence of RA, the stability of the RA-modulated phenotype was investigated by culture in the absence of RA. Little reexpression of type II collagen synthesis occurred in this period unless cultures were treated with 3 X 10(-6) M dihydrocytochalasin B to modify microfilament structures. Reexpression of the differentiated phenotype began between days 6-8 and was essentially complete by day 14. Substantial reexpression occurred by day 8 without a detectable increase in cell rounding. Colony formation, characteristic of primary chondrocytes, was infrequent even after reexpression was complete. These data suggest that the integrity of microfilament cytoskeletal structures can be a source of regulatory signals that mechanistically appear to be more proximal to phenotypic change than the overt changes in cell shape that accompany reexpression of subculture-modulated chondrocytes in agarose culture.

scholarly journals Selective emergence of differentiated chondrocytes during serum-free culture of cells derived from fetal rat calvaria.

1982 ◽  
Vol 92 (2) ◽  
pp. 493-504 ◽  
Author(s):  
L Rifas ◽  
J Uitto ◽  
V A Memoli ◽  
K E Kuettner ◽  
R W Henry ◽  
...  
Keyword(s):  
Primary Culture ◽  
Articular Chondrocytes ◽  
Type Ii Collagen ◽  
Progressive Increase ◽  
Ruthenium Red ◽  
Type I ◽  
Type Ii ◽  
Chondrocyte Phenotype ◽  
Rat Calvaria ◽  
Fetal Rat

Cells dispersed from the chondrocranial portions of fetal rat calvaria proliferated and performed specialized functions during primary culture in a chemically defined medium. Mature cultures were typified by multilayered clusters of redifferentiating cartilage cells. Flattened cells that lacked distinguishing features occupied areas between the clusters. Alkaline phosphate-enriched, ultrastructurally typical chondrocytes within the clusters were encased in a dense extracellular matrix that stained prominently for chondroitin sulfate proteoglycans. This matrix contained fibrils measuring 19 nm in diameter, which were associated with proteoglycan granules that preferentially bound ruthenium red. A progressive increase in the number of cells indicated the proliferation of certain elements in the primary culture. The cells in primary culture were biochemically as well as morphologically heterogeneous since they were found to synthesize type I and type II collagens. Homogeneous populations of redifferentiated chondrocytes were recovered as floating cells and were shown to express the chondrocyte phenotype in secondary culture. Subcultured cells synthesized type II collagen and its precursors almost exclusively and incorporated 35SO4 into proteoglycan monomer and aggregates to a greater degree than the cells in primary culture. The pattern of proteoglycan monomer and aggregate labeling resembled that of intact cartilage segments and bovine articular chondrocytes. Skin fibroblasts harvested from the same rat fetuses failed to proliferate when maintained under identical conditions. Hence, exogenous hormones, growth factors, and protein are not required for chondrocyte growth and maturation.

scholarly journals Analysis of collagen types synthesized by rabbit ear cartilage chondrocytes in vivo and in vitro

1984 ◽  
Vol 221 (1) ◽  
pp. 189-196 ◽  
Author(s):  
K Madsen ◽  
K von der Mark ◽  
M van Menxel ◽  
U Friberg
Keyword(s):  
Type I Collagen ◽  
Polyacrylamide Gel Electrophoresis ◽  
Type Ii Collagen ◽  
Type Iii Collagen ◽  
Type I ◽  
Type Ii ◽  
Collagen Types ◽  
Rabbit Ear ◽  
Ear Cartilage

This study compares the collagen types present in rabbit ear cartilage with those synthesized by dissociated chondrocytes in cell culture. The cartilage was first extracted with 4M-guanidinium chloride to remove proteoglycans. This step also extracted type I collagen. After pepsin solubilization of the residue, three additional, genetically distinct collagen types could be separated by fractional salt precipitation. On SDS (sodium dodecyl sulphate)/polyacrylamide-gel electrophoresis they were identified as type II collagen, (1 alpha, 2 alpha, 3 alpha) collagen and M-collagen fragments, a collagen pattern identical with that found in hyaline cartilage. Types I, II, (1 alpha, 2 alpha, 3 alpha) and M-collagen fragments represent 20, 75, 3.5, and 1% respectively of the total collagen. In frozen sections of ear cartilage, type II collagen was located by immunofluorescence staining in the extracellular matrix, whereas type I collagen was closely associated with the chondrocytes. Within 24h after release from elastic cartilage by enzymic digestion, auricular chondrocytes began to synthesize type III collagen, in addition to the above-mentioned collagens. This was shown after labelling of freshly dissociated chondrocytes with [3H]proline 1 day after plating, fractionation of the pepsin-treated collagens from medium and cell layer by NaCl precipitation, and analysis of the fractions by CM(carboxymethyl)-cellulose chromatography and SDS/polyacrylamide-gel electrophoresis. The 0.8 M-NaCl precipitate of cell-layer extracts consisted predominantly of type II collagen. The 0.8 M-NaCl precipitate obtained from the medium contained type I, II, and III collagen. In the supernatant of the 0.8 M-NaCl precipitation remained, both in the cell extract and medium, predominantly 1 alpha-, 2 alpha-, and 3 alpha-chains and M-collagen fragments. These results indicate that auricular chondrocytes are similar to chondrocytes from hyaline cartilage in that they produce, with the exception of type I collagen, the same collagen types in vivo, but change their cellular phenotype more rapidly after transfer to monolayer culture, as indicated by the prompt onset of type III collagen synthesis.

Fucoidan from Undaria pinnatifida regulates type II collagen and COX-2 expression via MAPK and PI3K pathways in rabbit articular chondrocytes

Biologia ◽  
2017 ◽  
Vol 72 (11) ◽  
Author(s):  
Abdul Rehman Phull ◽  
Song Ja Kim
Keyword(s):  
Articular Chondrocytes ◽  
Undaria Pinnatifida ◽  
Brown Seaweed ◽  
Type Ii Collagen ◽  
Sulfated Polysaccharide ◽  
Type Ii ◽  
Anti Cancer ◽  
Anti Oxidant ◽  
Cox 2 ◽  
Rabbit Articular Chondrocytes

AbstractFucoidan is a sulfated polysaccharide widely distributed in brown seaweed. It exhibits several bioactivities, such as anti-cancer, anti-tumor, anti-microbial, anti-diabetic and anti-oxidant properties. However, the effects of fucoidan in chondrocytes are not well established. Previously, we have reported

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