title: Transcriptional program of mouse osteoclast differentiation governed by the macrophage colony-stimulating factor and the ligand for the receptor activator of NFkappa B.
abstract: Cytokines macrophage colony stimulating factor (M-CSF) and the receptor activator of NFkappaB ligand (RANKL) induce differentiation of bone marrow hematopoietic precursor cells into bone-resorbing osteoclasts without the requirement for stromal cells of mesenchymal origin. We used this recently described mouse cell system and oligonucleotide microarrays representing about 9,400 different genes to analyze gene expression in hematopoietic cells undergoing differentiation to osteoclasts. The ability of microarrays to detect the genes of interest was validated by showing expression and expected regulation of several osteoclast marker genes. In total 750 known transcripts were up-regulated by > or =2-fold, and 91% of them at an early time in culture, suggesting that almost the whole differentiation program is defined already in pre-osteoclasts. As expected, M-CSF alone induced the receptor for RANKL (RANK), but also, unexpectedly, other RANK/NFkappaB pathway components (TRAF2A, PI3-kinase, MEKK3, RIPK1), providing a molecular explanation for the synergy of M-CSF and RANKL. Furthermore, interleukins, interferons, and their receptors (IL-1alpha, IL-18, IFN-beta, IL-11Ralpha2, IL-6/11R gp130, IFNgammaR) were induced by M-CSF. Although interleukins are thought to regulate osteoclasts via modulation of M-CSF and RANKL expression in stromal cells, we showed that a mix of IL-1, IL-6, and IL-11 directly increased the activity of osteoclasts by 8.5-fold. RANKL induced about 70 novel target genes, including chemokines and growth factors (RANTES (regulated on activation, normal T cell expressed and secreted), PDGFalpha, IGF1), histamine, and alpha1A-adrenergic receptors, and three waves of distinct receptors, transcription factors, and signaling molecules. In conclusion, M-CSF induced genes necessary for a direct response to RANKL and interleukins, while RANKL directed a three-stage differentiation program and induced genes for interaction with osteoblasts and immune and nerve cells. Thus, global gene expression suggests a more dynamic role of osteoclasts in bone physiology than previously anticipated.
authors.affiliation: Novartis Pharma Research, Arthritis and Bone Metabolism Therapeutic Area, CH-4002 Basel, Switzerland.
authors.forename: David
authors.initials: D
authors.lastname: Cappellen
authors.forename: Ngoc-Hong
authors.initials: NH
authors.lastname: Luong-Nguyen
authors.forename: Sandrine
authors.initials: S
authors.lastname: Bongiovanni
authors.forename: Olivier
authors.initials: O
authors.lastname: Grenet
authors.forename: Christoph
authors.initials: C
authors.lastname: Wanke
authors.forename: Mira
authors.initials: M
authors.lastname: Susa
mesh_terms: D000818:Animals; D002352:Carrier Proteins / Q000737:chemistry* / Q000378:metabolism; D002454:Cell Differentiation; D002478:Cells, Cultured; D008024:Ligands; D016173:Macrophage Colony-Stimulating Factor / Q000737:chemistry*; D008562:Membrane Glycoproteins / Q000737:chemistry* / Q000378:metabolism; D051379:Mice; D016328:NF-kappa B / Q000737:chemistry* / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D010010:Osteoclasts / Q000166:cytology / Q000378:metabolism / Q000473:pathology*; D010641:Phenotype; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D053245:RANK Ligand; D012313:RNA / Q000378:metabolism; D053246:Receptor Activator of Nuclear Factor-kappa B; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D014158:Transcription, Genetic; D015854:Up-Regulation
chemical_list: D002352:Carrier Proteins; D008024:Ligands; D008562:Membrane Glycoproteins; D016328:NF-kappa B; D053245:RANK Ligand; D053246:Receptor Activator of Nuclear Factor-kappa B; C505687:Tnfrsf11a protein, mouse; C505689:Tnfsf11 protein, mouse; D012313:RNA; D016173:Macrophage Colony-Stimulating Factor