title: Inner Ear Vestibular Signals Regulate Bone Remodeling via the Sympathetic Nervous System.
abstract: The inner ear vestibular system has numerous projections on central brain centers that regulate sympathetic outflow, and skeletal sympathetic projections affect bone remodeling by inhibiting bone formation by osteoblasts and promoting bone resorption by osteoclasts. In this study, we show that bilateral vestibular lesions in mice cause a low bone mass phenotype associated with decreased bone formation and increased bone resorption. This reduction in bone mass is most pronounced in lower limbs, is not associated with reduced locomotor activity or chronic inflammation, and could be prevented by the administration of the β-blocker propranolol and by genetic deletion of the β2-adrenergic receptor, globally or specifically in osteoblasts. These results provide novel experimental evidence supporting a functional autonomic link between central proprioceptive vestibular structures and the skeleton. Because vestibular dysfunction often affects the elderly, these results also suggest that age-related bone loss might have a vestibular component and that patients with inner ear pathologies might be at risk for fracture. Lastly, these data might have relevance to the bone loss observed in microgravity, as vestibular function is altered in this condition as well. © 2015 American Society for Bone and Mineral Research.
authors.affiliation: Department of Medicine, Vanderbilt University Medical Center, Vanderbilt Center for Bone Biology, Nashville, TN, USA.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Vignaux
authors.affiliation: Department of Medicine, Vanderbilt University Medical Center, Vanderbilt Center for Bone Biology, Nashville, TN, USA.
authors.forename: Jean Dlc
authors.initials: JD
authors.lastname: Ndong
authors.affiliation: Department of Orthopaedic Surgery & Rehabilitation/Department of VA, Vanderbilt University Medical Center, Vanderbilt Center for Bone Biology, Nashville, TN, USA.
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Perrien
authors.affiliation: Department of Medicine, Vanderbilt University Medical Center, Vanderbilt Center for Bone Biology, Nashville, TN, USA.
authors.forename: Florent
authors.initials: F
authors.lastname: Elefteriou
mesh_terms: D000818:Animals; D016723:Bone Remodeling; D005260:Female; D051379:Mice; D018345:Mice, Knockout; D010006:Osteoblasts / Q000378:metabolism* / Q000473:pathology; D010024:Osteoporosis / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D011433:Propranolol / Q000009:adverse effects / Q000494:pharmacology; D013564:Sympathetic Nervous System / Q000378:metabolism* / Q000473:pathology; D015837:Vestibular Diseases / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D014722:Vestibule, Labyrinth / Q000378:metabolism* / Q000473:pathology
chemical_list: D011433:Propranolol
keywords: AGING; BONE; INNER EAR; MICROGRAVITY; OSTEOPOROSIS; SYMPATHETIC NERVOUS SYSTEM; VESTIBULAR SYSTEM; β2-ADRENERGIC RECEPTOR