title: Ontogeny of rat chondrocyte proliferation: studies in embryo, adult and osteoarthritic (OA) cartilage.
abstract: The aim of this work was to study the ontogeny of chondrocyte cell division using embryo, adult and osteoarthritic (OA) cartilage. We searched for mitosis phases and performed a comparative evaluation of mitotic index, basic fibroblast growth factor b (FGFb), transforming growth factor beta1 (TGF-beta1) receptors, cyclin dependent kinase (CDK1) and Cyclin-B expression in fetal, neonate, 3, 5, 8 weeks old rats and experimental OA. Our results showed that mitosis phases were observed in all normal cartilage studied, although, we found a decrease in mitotic index in relation to tissue development. No mitosis was detected in OA cartilage. We also found a statistical significant reduction in cell number in OA cartilage, compared with the normal tissue. Furthermore, FGFb and TGF-beta1 receptors diminished in relation to tissue development, and were very scarce in experimental OA. Western blot assays showed CDK-1 expression in all cases, including human-OA cartilage. Similar results were observed for Cyclin-B, except for 8 weeks, when it was not expressed. Our results suggest that cell division seems to be scarce, if not absent within the OA cartilage studied. Nevertheless, the existence of factors essential for cell division leaves open the question concerning chondrocyte proliferation in OA cartilage, which is likely to be present in the early stages of the disease.
authors.affiliation: Departamento de Patologia Experimental, Centro de Investigacion y de Estudios Avanzados. Instituto Politecnico Nacional (CINVESTAV-IPN), Mexico.
authors.forename: Madai A
authors.initials: MA
authors.lastname: Gomez-Camarillo
authors.forename: Juan B
authors.initials: JB
authors.lastname: Kouri
mesh_terms: D030201:Activin Receptors, Type I / Q000378:metabolism; D000818:Animals; D016203:CDC2 Protein Kinase / Q000378:metabolism; D002356:Cartilage / Q000166:cytology / Q000196:embryology* / Q000254:growth & development*; D049109:Cell Proliferation; D019902:Chondrocytes / Q000166:cytology* / Q000378:metabolism; D019926:Cyclin B / Q000378:metabolism; D008938:Mitosis; D010003:Osteoarthritis / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases; D051381:Rats; D017208:Rats, Wistar; D000077293:Receptor, Transforming Growth Factor-beta Type I; D017468:Receptors, Fibroblast Growth Factor / Q000378:metabolism; D018125:Receptors, Transforming Growth Factor beta / Q000378:metabolism
chemical_list: D019926:Cyclin B; D017468:Receptors, Fibroblast Growth Factor; D018125:Receptors, Transforming Growth Factor beta; D017346:Protein Serine-Threonine Kinases; D016203:CDC2 Protein Kinase; D030201:Activin Receptors, Type I; D000077293:Receptor, Transforming Growth Factor-beta Type I; C000625843:Tgfbr1 protein, rat