The cellular activity in bone and cartilage tissue is controlled by substances present in the osseous environment. Using representative cell lines, modulation of osteoblastic and chondrocytic phenotypic markers such as hormone-responsiveness, enzymatic activities, and matrix production by osteotropic factors was examined in vitro. In UMR 106 cells, a rat osteoblast-derived osteosarcoma cell line, a differential distribution of EGF and PTH receptors over proliferating and quiescent cells, respectively, was observed. EGF treatment resulted in expansion of a less differentiated population characterized by decreased PTH- and CT-stimulated adenylate cyclase and binding capacity, and increased CGRP-responsiveness. Using immunocytolysis, a mixed osseous cell population (OBCK6) was derived from fetal rat calvarial cells. Subsequent dilution cloning yielded two cell lines, the CFK1 line with osteoblastic characteristics and the CFK2 line with chondrocytic properties. Although only the OBCK6 cells deposited a mineralized matrix in vitro, organic matrix components were produced by the other two lines. EGF stimulated proliferation in both CFK1 and CFK2 cells. Retinoic acid decreased cell proliferation, PTH-responsiveness, and alkaline phosphatase activity, caused cell shape change and population reorganization, and increased EGF receptors in CFK1 cells. Induction of cartilage specific matrix components (type II collagen, proteoglycan core protein, link protein, and thrombospondin) was observed in CFK2 cells maintained in culture without passaging and could be regulated by EGF, PTH, dexamethasone, and retinoic acid. Thus, peptidergic and steroidal factors have been employed to modulate functional activity and cell cycle kinetics, and have resulted in the characterization of discrete stages of differentiation of osteoblastic and chondrocytic populations in vitro.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.39329 |
| Date | January 1992 |
| Creators | Bernier, Suzanne M. (Suzanne Marie) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Physiology.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001277598, proquestno: NN74822, Theses scanned by UMI/ProQuest. |
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