Growth and differentiation of murine cartilage cells in vitro following a short-term exposure to triamcinolone acetonide.
Measurements of 3H-thymidine incorporation, quantitative autoradiography and morphometry were used to evaluate cell behavior during the recovery of mandibular condylar cartilage cultures following short-term exposure to a corticosteroid hormone in vitro. Apical segments of mandibular condyles of newborn mice were initially incubated in the presence of the hormone triamcinolone acetonide (10(-6) M) for 24 h and were thereafter cultured for additional 6 days in hormone-free medium. The present results indicated that the treatment led to a decrease in the rate of incorporation of 3H-thymidine, a feature that lasted for 48 h following the removal of the hormone. Quantitative 3H-thymidine autoradiography of explants that were labeled in the presence of the hormone further substantiated the initial suppressive effect of the hormone on cellular proliferation, a feature that was followed by a recovery. Differences were noted in the pattern of distribution of labeled cells: in control explants, labeled cells progressively moved from the chondroprogenitor compartment into the differentiated portion of the cartilage; in hormone-treated explants, 3H-thymidine labeled cells were confined to the progenitor layer up to 5 days after the treatment and only then appeared in the chondrocytic compartment. The hormone's adverse effect upon differentiation was manifested by both morphology, and by causing a significant increase in the size of the progenitor layer (up to 50.5% on 4th post-treatment day) along with a 70.5% reduction in the size of chondroblastic layer. We conclude that a short-term exposure to a glucocorticoid hormone in vitro interferes with proliferation of chondroprogenitor cells and their subsequent differentiative pathway.(ABSTRACT TRUNCATED AT 250 WORDS)
Weiss
A
A
Laboratory for Musculoskeletal Research, Technion-Israel Institute of Technology, Haifa.
Livne
E
E
Silbermann
M
M
D000818:Animals; D002356:Cartilage / Q000166:cytology* / Q000187:drug effects / Q000254:growth & development; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D066298:In Vitro Techniques; D051379:Mice; D008813:Mice, Inbred ICR; D013936:Thymidine; D014222:Triamcinolone Acetonide / Q000494:pharmacology*
D014222:Triamcinolone Acetonide; D013936:Thymidine