title: Modulation of osteoclast differentiation and bone resorption by Rho GTPases.
abstract: Bone is a dynamic tissue constantly renewed through a regulated balance between bone formation and resorption. Excessive bone degradation by osteoclasts leads to pathological decreased bone density characteristic of osteolytic diseases such as post-menopausal osteoporosis or bone metastasis. Osteoclasts are multinucleated cells derived from hematopoietic stem cells via a complex differentiation process. Their unique ability to resorb bone is dependent on the formation of the actin-rich sealing zone. Within this adhesion structure, the plasma membrane differentiates into the ruffled border where protons and proteases are secreted to demineralize and degrade bone, respectively. On the bone surface, mature osteoclasts alternate between stationary resorptive and migratory phases. These are associated with profound actin cytoskeleton reorganization, until osteoclasts die of apoptosis. In this review, we highlight the role of Rho GTPases in all the steps of osteoclasts differentiation, function, and death and conclude on their interest as targets for treatment of osteolytic pathologies.
authors.affiliation: Montpellier University; CNRS UMR 5237; Centre de Recherche de Biochimie Macromoléculaire; Montpellier, France.
authors.forename: Heiani
authors.initials: H
authors.lastname: Touaitahuata
authors.affiliation: Montpellier University; CNRS UMR 5237; Centre de Recherche de Biochimie Macromoléculaire; Montpellier, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Blangy
authors.affiliation: Montpellier University; CNRS UMR 5237; Centre de Recherche de Biochimie Macromoléculaire; Montpellier, France.
authors.forename: Virginie
authors.initials: V
authors.lastname: Vives
mesh_terms: D000199:Actins / Q000378:metabolism; D001862:Bone Resorption / Q000378:metabolism* / Q000473:pathology; D002454:Cell Differentiation; D020662:Guanine Nucleotide Exchange Factors / Q000378:metabolism; D006801:Humans; D010010:Osteoclasts / Q000166:cytology / Q000378:metabolism*; D053245:RANK Ligand / Q000378:metabolism; D020764:cdc42 GTP-Binding Protein / Q000378:metabolism; D020744:rac GTP-Binding Proteins / Q000378:metabolism; D020741:rho GTP-Binding Proteins / Q000378:metabolism*
chemical_list: D000199:Actins; D020662:Guanine Nucleotide Exchange Factors; D053245:RANK Ligand; D020764:cdc42 GTP-Binding Protein; D020744:rac GTP-Binding Proteins; D020741:rho GTP-Binding Proteins
keywords: Cdc42; RANK ligand; Rac; Rho GTPase; RhoU; actin; bone and bones; guanine nucleotide exchange factor; osteoclast; podosome