Contribution of marrow stromal cells to the regulation of osteoblast proliferation in rats: evidence for the involvement of insulin-like growth factors
1991; Elsevier BV; Volume: 13; Issue: 3 Linguagem: Inglês
10.1016/0169-6009(91)90069-c
ISSN1878-0628
AutoresR.W. Zhang, David J. Simmons, Roger S. Crowther, Subburaman Mohan, David J. Baylink,
Tópico(s)Bone and Dental Protein Studies
ResumoFibroblast-like marrow stromal cells are believed to play a role in the maintenance of osteoblast populations at the marrow-bone interface. We now report that this interaction may be very specific. Stromal cell conditioned medium (SC-CM) stimulated DNA synthesis and proliferation in culture of neonatal rat calvarial osteoblasts at low concentrations (1.25-5%), but was inhibitory at 10%. At growth promoting effective concentrations, the activity of osteoblast alkaline phosphatase was decreased. This action was selective since SC-CM failed to promote the growth of rat calvarial fibroblasts. Characterization of the SC-CM indicated the cells produced IGF-I and -II and a wide range of molecular weight fractions with putative stimulatory action (FPLC analysis using Superose 12 and 6 gel permeation columns). HPAE-PAD analysis showed that some elements were glycosylated, and the composition suggested the presence of N- and O-linked oligosaccharide chains. Because rat marrow stromal fibroblast-like cells produce a number of osteotropic factors which affect calvarial osteoblast growth, these interactions may be important to considerations about the etiology of the osteoporoses.
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