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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2005-11-28
pubmed:abstractText
We have examined the effects of growth factor stimulation on superficial and growth zone chondrocyte populations. Zonal articular chondrocytes from 8-month-old Spanish goat distal femurs were plated in monolayer cultures and stimulated by using insulin-like growth factor I (IGF-I), basic fibroblast growth factor (bFGF), and transforming growth factor-beta1 (TGF-beta1). Gene expression for collagen I and II, aggrecan, and superficial zone protein were evaluated every week for 3 weeks. Finally, proteoglycan and collagen deposition were measured for each experimental group. Major differences existed in the behavior of superficial and growth zone chondrocytes, the most apparent being the higher capacity for protein synthesis by the growth zone population. Variations also existed regarding growth factor treatment. TGF-beta1 had the greatest effect on proliferation over 8 days. With respect to differentiation, IGF-I increased average collagen II gene expression in the growth zone populations in comparison with growth zone controls. IGF-I increased aggrecan gene expression for the same groups. Superficial zone populations exhibited lower collagen II, collagen I, and aggrecan gene expression than the growth zone populations under all conditions. However, superficial zone protein expression was dramatically elevated in superficial zone populations by TGF-beta1. Collagen I expression showed a general increase under all conditions compared with initial values. Combined biosynthesis results showed that the superficial populations secreted little to no collagen, especially collagen II, in comparison with their growth zone counterparts. Glycosaminoglycan production was also much lower than for the growth zone groups. TGF-beta1 and IGF-I increased collagen II production in the growth zone populations. TGF-beta1 increased glycosaminoglycan secretions in the superficial zone populations and in the growth zone populations, whereas IGF-I produced an increase in glycosaminoglycan secretion only in the growth zone populations. Thus, growth factors elicit different proliferation, gene expression, and biosynthesis responses from zonal chondrocyte subpopulations.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0302-766X
pubmed:author
pubmed:issnType
Print
pubmed:volume
322
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
463-73
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Growth factor impact on articular cartilage subpopulations.
pubmed:affiliation
Department of Bioengineering, MS-142, Rice University, P.O. Box 1892, Houston, TX 77251, USA. edarling@duke.edu
pubmed:publicationType
Journal Article