title: Bone Marrow Adipose Tissue Deficiency Increases Disuse-Induced Bone Loss in Male Mice.
abstract: Bone marrow adipose tissue (MAT) is negatively associated with bone mass. Since osteoblasts and adipocytes are derived from the same precursor cells, adipocyte differentiation may occur at the expense of osteoblast differentiation. We used MAT-deficient KitW/W-v(MAT-) mice to determine if absence of MAT reduced bone loss in hindlimb-unloaded (HU) mice. Male MAT- and wild-type (WT) mice were randomly assigned to a baseline, control or HU group (n = 10 mice/group) within each genotype and HU groups unloaded for 2 weeks. Femurs were evaluated using micro-computed tomography, histomorphometry and targeted gene profiling. MAT- mice had a greater reduction in bone volume fraction after HU than did WT mice. HU MAT- mice had elevated cancellous bone formation and resorption compared to other treatment groups as well as a unique profile of differentially expressed genes. Adoptive transfer of WT bone marrow-derived hematopoietic stem cells reconstituted c-kit but not MAT in KitW/W-vmice. The MAT- WT → KitW/W-vmice lost cancellous bone following 2 weeks of HU. In summary, results from this study suggest that MAT deficiency was not protective, and was associated with exaggerated disuse-induced cancellous bone loss.
authors.affiliation: Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR 97331,USA.
authors.forename: Jessica A
authors.initials: JA
authors.lastname: Keune
authors.affiliation: Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR 97331,USA.
authors.forename: Carmen P
authors.initials: CP
authors.lastname: Wong
authors.affiliation: Biostatistics Program, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR 97331,USA.
authors.forename: Adam J
authors.initials: AJ
authors.lastname: Branscum
authors.affiliation: Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR 97331,USA.|Center for Healthy Aging Research, Oregon State University, Corvallis, OR 97331, USA.
authors.forename: Urszula T
authors.initials: UT
authors.lastname: Iwaniec
authors.affiliation: Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR 97331,USA.|Center for Healthy Aging Research, Oregon State University, Corvallis, OR 97331, USA.
authors.forename: Russell T
authors.initials: RT
authors.lastname: Turner
mesh_terms: D000273:Adipose Tissue / Q000473:pathology*; D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging / Q000209:etiology* / Q000473:pathology*; D000818:Animals; D001696:Biomechanical Phenomena; D015519:Bone Density; D001853:Bone Marrow / Q000473:pathology*; D004195:Disease Models, Animal; D020869:Gene Expression Profiling; D005838:Genotype; D019417:Hindlimb Suspension / Q000009:adverse effects; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D010006:Osteoblasts / Q000378:metabolism; D010010:Osteoclasts / Q000378:metabolism; D059467:Transcriptome; D055114:X-Ray Microtomography