Linked Life Data

9696350

Source:http://linkedlifedata.com/resource/pubmed/id/9696350

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1998-10-5
pubmed:abstractText
Chondrocyte terminal differentiation is associated with cellular hypertrophy increased activity of plasma membrane alkaline phosphatase and the synthesis of collagen type X. The hypertrophic phenotype of cultured chondrocytes can be stimulated by ascorbic acid but the underlying mechanisms for this phenotypic change are unclear. As ascorbic acid is central to many hydroxylation reactions, the possibility was examined that its pro-differentiating effects are mediated by its effects on collagen and vitamin D metabolite formation. In vitro studies indicated that ascorbic acid-induced chondrocyte alkaline phosphatase activity was inhibited by the addition of both collagen and proteoglycan synthesis inhibitors. The addition of arginine-glycine-aspartic acid (RGD)-containing peptides also resulted in lower alkaline phosphatase activity. Chicks supplemented with dietary ascorbic acid had higher concentrations of both collagen and proteoglycans within their growth plates but the chondrocyte maturation rate was unaltered. No evidence was obtained to suggest that ascorbic acid-induced collagen production was mediated by lipid peroxidation. In addition, supplementation with dietary ascorbic acid resulted in higher serum 1,25-dihydroxyvitamin D3 concentrations and increased chondrocyte vitamin D receptor number. Ascorbic acid-treated chondrocytes maintained in vitro also had increased vitamin D receptor numbers but chondrocyte receptor affinity for 1,25-dihydroxyvitamin D3 was unaltered. These results indicate that ascorbic acid promotes both chondrocyte matrix production and 1,25-dihydroxyvitamin D3 synthesis, accompanied by upregulation of the vitamin D receptor. Thus, ascorbic acid may be causing amplification of the vitamin D receptor-dependent genomic response to 1,25-dihydroxyvitamin D, resulting in promotion of terminal differentiation. Strong evidence is provided to support the hypothesis that ascorbic acid-induced chondrocyte terminal differentiation is mediated by interactions between integrins and RGD-containing cartilage matrix proteins.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0171-9335
pubmed:author
pubmed:issnType
Print
pubmed:volume
76
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
110-8
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Ascorbic acid-induced chondrocyte terminal differentiation: the role of the extracellular matrix and 1,25-dihydroxyvitamin D.
pubmed:affiliation
Roslin Institute (Edinburgh), Midlothian, Scotland, UK.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't