Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1989-8-18
pubmed:abstractText
When cells enzymatically isolated from fetal rat calvaria (RC cells) are cultured in vitro in the presence of ascorbic acid and Na beta-glycerophosphate, discrete three-dimensional nodules form with the histologic, immunohistochemical, and ultrastructural characteristics of bone (Bellows et al; Calcified Tissue International 38:143-154, 1986; Bhargava et al., Bone, 9:155-163, 1988). Quantitation of the number of bone nodules that forms provides a colony assay for osteoprogenitor cells present in the RC population (Bellows and Aubin, Develop. Biol., 133:8-13, 1989). Continuous culture with either epidermal growth factor (EGF) or transforming growth factor beta (TGF-beta) results in dose-dependent inhibition of bone nodule formation; however, the former causes increased proliferation and saturation density, while the latter reduces both parameters. Addition of EGF (48 h pulse, 2-200 ng/ml) to RC cells at day 1 after plating results in increased proliferation and population saturation density and an increased number of bone nodules formed. Similar pulses at confluence and in postconfluent multilayered cultures when nodules first begin forming (approx. day 11) inhibited bone nodule formation and resulted in a smaller stimulation of cell proliferation. Forty-eight hour pulses of TGF-beta (0.01-1 ng/ml) reduced bone nodule formation and proliferation at all times examined, with pulses on day 1 causing maximum inhibition. The effects of pulses with TGF-beta and EGF on inhibition of nodule formation are independent of the presence of serum in the culture medium during the pulse. The data suggest that whereas EGF can either stimulate or inhibit the formation of bone nodules depending upon the time and duration of exposure, TGF-B inhibits bone nodule formation under all conditions tested. Moreover, these effects on osteoprogenitor cell differentiation do not always correlate with the effects of the growth factors on RC cell proliferation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0021-9541
pubmed:author
pubmed:issnType
Print
pubmed:volume
140
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
386-95
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Effects of transforming growth factor beta and epidermal growth factor on cell proliferation and the formation of bone nodules in isolated fetal rat calvaria cells.
pubmed:affiliation
MRC Group in Periodontal Physiology, University of Toronto, Ontario, Canada.
pubmed:publicationType
Journal Article, Comparative Study