Year: 2000
Type: article
Abstract: The expression of several cartilage-specific genes (collagen al (II) and aggrecan), collagen a/I (I) and endogenous TGF-fll was characterized during in vitro chondrogenesis in rabbit periosteal explants and correlated with the histological changes.Explants were cultured in agarose for 0, 3, 7, l4, 21, or 28 days with l0 ng/mL TGF-/31 added for the first 2 days and RNA levels were quantitated by dot blot analysis.The first observed effect of exogenous TGF-/31 was to briefly increase the expression of endogenous TGF-fll, which then declined between days 3-7.Aggrecan gene expression increased within 3 days and reached a maximal (%6-fold) increase at 21 days.Procollagen 0.11 (ll) RNA showed a larger increase from approximately ll fold at 7 days to over 200 fold after 21 days.The change in procollagen al (II) gene expression was clearly dependent on TGF-fll as explants cultured without added TGF-/31 showed a much smaller increase in RNAP'°°°'l"g°" "'1'") after 2 weeks.Collagen al (I) RNA levels decreased markedly (80%) at the same time that collagen al (II) RNA levels were increasing, and this response was also TGF-/31 dependent.This study demonstrates that TGF-/31 significantly enhances in vitro chondrogenesis in rabbit periosteal explants and acts, at least in part, by inducing expression of cartilage-specific genes and inhibiting expression of collagen a 1 (I).Its effects are most likely mediated by the initiation of a cascade of events.
Source: Biomedical Research
Institution: Mayo Clinic
Language: English
Subfield: Rheumatology
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W1981547110