Nuclear factor of activated T cells c1 induces osteoclast-associated receptor gene expression during tumor necrosis factor-related activation-induced cytokine-mediated osteoclastogenesis.
Osteoclast differentiation from hematopoietic precursors is controlled by the tumor necrosis factor family member tumor necrosis factor-related activation-induced cytokine (TRANCE) via induction of various transcription factors, including nuclear factor of activated T cells (NFAT) c1. During osteoclast differentiation, NFATc1 is further activated via calcium signaling when costimulatory receptors expressed on osteoclast precursors, such as osteoclast-associated receptor (OSCAR), are stimulated. Here we show that NFATc1 expression precedes that of OSCAR during TRANCE-mediated osteoclastogenesis and that inhibition of NFATc1 by cyclosporin A abolishes TRANCE-induced OSCAR expression and subsequent osteoclast differentiation. Moreover, we show that the 1.0-kb promoter region of the OSCAR gene contains three potential NFATc1-binding sites. Induction of an OSCAR promoter-luciferase reporter is significantly increased when transiently transfected into 293T cells in combination with NFATc1 expression plasmid. Deletion and site-directed mutant constructs confirmed that NFATc1-binding sites are both functional and NFATc1-specific. Furthermore, NFATc1 synergistically activates an OSCAR reporter construct together with microphthalmia transcription factor and PU.1, transcription factors previously shown to be critical for osteoclast differentiation. In addition, a plasmid expressing constitutively active MAP kinase kinase 6 enhances the transactivation activity of NFATc1/microphthalmia transcription factor/PU.1 on the OSCAR promoter. Taken together, our results indicate that NFATc1 is an important transcription factor in the induction of OSCAR during osteoclastogenesis. Elucidation of NFATc1 as a transcription factor for OSCAR expression implies the presence of a positive feedback circuit of TRANCE-induced activation of NFATc1, involving NFATc1-mediated OSCAR expression and its subsequent activation of NFATc1, necessary for efficient differentiation of osteoclasts.
Kim
Kabsun
K
Medical Research Center for Gene Regulation, Chonnam National University Medical School, Gwangju, 501-746, Korea.
Kim
Jung Ha
JH
Lee
Junwon
J
Jin
Hye-Mi
HM
Lee
Seoung-Hoon
SH
Fisher
David E
DE
Kook
Hyun
H
Kim
Kyung Keun
KK
Choi
Yongwon
Y
Kim
Nacksung
N
D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D015152:Blotting, Northern; D015153:Blotting, Western; D001854:Bone Marrow Cells / Q000166:cytology; D002352:Carrier Proteins / Q000378:metabolism; D002454:Cell Differentiation; D002460:Cell Line; D047369:Chromatin Immunoprecipitation; D016572:Cyclosporine / Q000494:pharmacology; D016207:Cytokines / Q000378:metabolism*; D017353:Gene Deletion; D005786:Gene Expression Regulation; D005822:Genetic Vectors; D006801:Humans; D008156:Luciferases / Q000378:metabolism; D048669:MAP Kinase Kinase 6 / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000378:metabolism; D051379:Mice; D051739:Microphthalmia-Associated Transcription Factor / Q000378:metabolism; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D050778:NFATC Transcription Factors / Q000378:metabolism / Q000502:physiology*; D010957:Plasmids / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D014176:Protein Biosynthesis; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D053245:RANK Ligand; D053246:Receptor Activator of Nuclear Factor-kappa B; D011956:Receptors, Cell Surface / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015534:Trans-Activators / Q000378:metabolism; D015533:Transcriptional Activation; D014162:Transfection; D015854:Up-Regulation; D000099232:Proto-Oncogene Protein Spi-1
D002352:Carrier Proteins; D016572:Cyclosporine; D016207:Cytokines; D008156:Luciferases; D048669:MAP Kinase Kinase 6; D008562:Membrane Glycoproteins; D051739:Microphthalmia-Associated Transcription Factor; D050778:NFATC Transcription Factors; D011518:Proto-Oncogene Proteins; D053245:RANK Ligand; D053246:Receptor Activator of Nuclear Factor-kappa B; D011956:Receptors, Cell Surface; D015534:Trans-Activators; D000099232:Proto-Oncogene Protein Spi-1; C512828:OSCAR protein, human; C450519:Oscar protein, mouse; C505686:TNFRSF11A protein, human; C505688:TNFSF11 protein, human; C505687:Tnfrsf11a protein, mouse; C505689:Tnfsf11 protein, mouse