title: Ovariectomy-induced bone loss occurs independently of B cells.
abstract: Estrogen withdrawal is associated with a significant expansion in B cell precursor and mature B cell populations. However, despite significant circumstantial evidence the role of B lineage cells in ovariectomy-induced bone loss in vivo is unclear. In vitro studies have demonstrated that mature B cells have the potential to both positively and negatively impact osteoclastogenesis by virtue of their capacity to secrete pro-osteoclastogenic cytokines including receptor activator of NFkappaB ligand (RANKL), as well as anti-osteoclastogenic cytokines such as osteoprotegerin (OPG) and transforming growth factor beta (TGFbeta). Although several studies have suggested that expansion of the B lineage following ovariectomy may play a key role in the etiology of ovariectomy-induced bone loss, in vivo studies to directly test this notion have yet to be conducted. In this study, we performed ovariectomy on microMT(-/-) mice which are specifically deficient in mature B cells. Analysis of bone mineral density (BMD) by dual-energy X-ray absorptiometry (DXA) and micro-computed tomography (CT) demonstrate that mature B cell-deficient mice undergo an identical loss of bone mass relative to wild-type (WT) control mice. Our data demonstrate that mature B cells are not central mediators of ovariectomy-induced bone loss in vivo.
authors.affiliation: Division of Endocrinology and Metabolism, Emory University School of Medicine, Atlanta, Georgia 30322, USA.
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.forename: Aimin
authors.initials: A
authors.lastname: Li
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Yang
authors.forename: M Neale
authors.initials: MN
authors.lastname: Weitzmann
mesh_terms: D015502:Absorptiometry, Photon; D000818:Animals; D001402:B-Lymphocytes / Q000378:metabolism / Q000502:physiology*; D015519:Bone Density; D001862:Bone Resorption / Q000209:etiology / Q000235:genetics / Q000378:metabolism*; D005260:Female; D051379:Mice; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains; D008954:Models, Biological; D010052:Ovariectomy / Q000009:adverse effects*; D014057:Tomography, X-Ray Computed