Stem cell factor stimulates chicken osteoclast activity in vitro.
Stem cell factor (SCF) is a polypeptide growth factor active on multiple cell types, mainly of hematopoietic origin. We studied the effects of avian SCF on the differentiation of chicken osteoclasts from their putative progenitors as well as on the bone-resorbing activity of terminally differentiated osteoclasts. Osteoclast formation was analyzed in long-term cocultures of osteoblasts and nonadherent, osteoclast-depleted bone marrow cells. Osteoclast activity was studied in short-term (48 h) cultures of bone marrow cell populations enriched for osteoclasts, on dentine slices. SCF strongly enhanced osteoclast differentiation. The IL-6-related chicken myelomonocytic growth factor (cMGF) had a similar effect, and the effects of SCF and cMGF were additive. SCF, but not cMGF, also stimulated the bone-resorbing activity of existing osteoclasts. As osteoblasts have been found to regulate osteoclast activity and formation, chicken osteoblasts were tested for their ability to express and secrete SCF. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis showed that osteoblasts express SCF mRNA and that parathyroid hormone increases expression levels about fourfold. SCF did not accumulate in the culture medium, but remained cell (osteoblasts) surface associated.
van't Hof
R J
RJ
Department of Cell Biology, University of Leiden, The Netherlands.
von Lindern
M
M
Nijweide
P J
PJ
Beug
H
H
D000135:Acid Phosphatase / Q000302:isolation & purification; D000818:Animals; D030161:Avian Proteins; D001681:Biological Assay; D001862:Bone Resorption; D002450:Cell Communication; D002454:Cell Differentiation / Q000187:drug effects; D002462:Cell Membrane / Q000737:chemistry; D002478:Cells, Cultured; D002642:Chick Embryo; D017077:Culture Media, Conditioned / Q000494:pharmacology; D016207:Cytokines; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D006133:Growth Substances / Q000494:pharmacology; D006651:Histocytochemistry; D007150:Immunohistochemistry; D036341:Intercellular Signaling Peptides and Proteins; D007527:Isoenzymes / Q000302:isolation & purification; D010006:Osteoblasts / Q000502:physiology; D010010:Osteoclasts / Q000187:drug effects* / Q000502:physiology; D016133:Polymerase Chain Reaction; D019089:Stem Cell Factor / Q000302:isolation & purification / Q000494:pharmacology*; D000071681:Tartrate-Resistant Acid Phosphatase
D030161:Avian Proteins; D017077:Culture Media, Conditioned; D016207:Cytokines; D006133:Growth Substances; D036341:Intercellular Signaling Peptides and Proteins; D007527:Isoenzymes; C059626:MGF protein, chicken; D019089:Stem Cell Factor; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase