Abstract
The two pathways to osteoclastogenesis, RANKL-mediated and CD98-mediated osteoclastogenesis, have recently been reported. RANKL, OCIF, and TIMP-3 mRNAs are not found in monocytes freshly isolated or incubated with anti-FRP-1/CD98hc antibody. RANK, TACE, and M-CSF mRNAs can be detected in these cells. Interestingly, the expressed amount of RANK mRNA increases by cultivation of monocytes with anti-CD98hc antibody and maximal expression is observed in osteoclast-like cells. CD98-mediated cell aggregation and multinucleated giant cell formation are blocked by OCIF. OCIF also suppressed the CD98-mediated induction of Sp1 and c-src mRNAs in monocytes. Soluble RANK shows no effect on CD98-mediated cell aggregation and multinucleated giant cell formation. When blood monocytes were incubated with RANKL and M-CSF, c-src and Sp1 mRNAs were first found in blood monocytes incubated with these cytokines for 7 days. On the contrary, c-src mRNA could be detected 3 h after treatment of blood monocytes with anti-CD98hc mAb. LAT-1 mRNA was not found, and the expression levels of Y(+)LAT-1 and Y(+)LAT-2 mRNAs were not changed in monocytes stimulated without or with anti-CD98hc mAb or RANKL and M-CSF. An inhibitory mAb directed against CD98hc, HBJ 127, shows a suppressive effect on RANKL-mediated cell aggregation and cell fusion. Thus, there is cross-talk between these two pathways.
Copyright 2001 Academic Press.
MeSH terms
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Antibodies, Monoclonal / immunology*
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Antigens, CD / physiology*
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Apoptosis Regulatory Proteins
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CSK Tyrosine-Protein Kinase
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Carrier Proteins / pharmacology*
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Carrier Proteins / physiology*
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Cell Aggregation
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Cell Fusion
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Fusion Regulatory Protein-1
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Glycoproteins / genetics
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Glycoproteins / pharmacology*
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Glycoproteins / physiology
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Humans
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Macrophage Colony-Stimulating Factor / pharmacology
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Membrane Glycoproteins / pharmacology*
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Membrane Glycoproteins / physiology
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Osteoclasts / physiology*
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Osteoprotegerin
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Protein-Tyrosine Kinases / genetics
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RANK Ligand
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RNA, Messenger / analysis
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Receptor Activator of Nuclear Factor-kappa B
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Receptors, Cytoplasmic and Nuclear / genetics
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Receptors, Cytoplasmic and Nuclear / physiology
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Receptors, Tumor Necrosis Factor
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Sp1 Transcription Factor / genetics
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TNF-Related Apoptosis-Inducing Ligand
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Tumor Necrosis Factor-alpha / physiology
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src-Family Kinases
Substances
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Antibodies, Monoclonal
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Antigens, CD
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Apoptosis Regulatory Proteins
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Carrier Proteins
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Fusion Regulatory Protein-1
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Glycoproteins
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Membrane Glycoproteins
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Osteoprotegerin
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RANK Ligand
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RNA, Messenger
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Receptor Activator of Nuclear Factor-kappa B
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Receptors, Cytoplasmic and Nuclear
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Receptors, Tumor Necrosis Factor
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Sp1 Transcription Factor
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TNF-Related Apoptosis-Inducing Ligand
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TNFRSF11A protein, human
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TNFRSF11B protein, human
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TNFSF10 protein, human
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TNFSF11 protein, human
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Tumor Necrosis Factor-alpha
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Macrophage Colony-Stimulating Factor
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Protein-Tyrosine Kinases
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CSK Tyrosine-Protein Kinase
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src-Family Kinases
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CSK protein, human