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Treyball A, Bergeron AC, Brooks DJ, Langlais AL, Hashmi H, Nagano K, Barlow D, Neilson RJ, Roy TA, Nevola KT, Houseknecht KL, Baron R, Bouxsein ML, Guntur AR, Motyl KJ. Propranolol Promotes Bone Formation and Limits Resorption Through Novel Mechanisms During Anabolic Parathyroid Hormone Treatment in Female C57BL/6J Mice. J Bone Miner Res 2022; 37:954-971. [PMID: 35122666 PMCID: PMC9098680 DOI: 10.1002/jbmr.4523] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 01/15/2022] [Accepted: 01/30/2022] [Indexed: 11/09/2022]
Abstract
Although the nonselective β-blocker, propranolol, improves bone density with parathyroid hormone (PTH) treatment in mice, the mechanism of this effect is unclear. To address this, we used a combination of in vitro and in vivo approaches to address how propranolol influences bone remodeling in the context of PTH treatment. In female C57BL/6J mice, intermittent PTH and propranolol administration had complementary effects in the trabecular bone of the distal femur and fifth lumbar vertebra (L5 ), with combination treatment achieving microarchitectural parameters beyond that of PTH alone. Combined treatment improved the serum bone formation marker, procollagen type 1 N propeptide (P1NP), but did not impact other histomorphometric parameters relating to osteoblast function at the L5 . In vitro, propranolol amplified the acute, PTH-induced, intracellular calcium signal in osteoblast-like cells. The most striking finding, however, was suppression of PTH-induced bone resorption. Despite this, PTH-induced receptor activator of nuclear factor κ-B ligand (RANKL) mRNA and protein levels were unaltered by propranolol, which led us to hypothesize that propranolol could act directly on osteoclasts. Using in situ methods, we found Adrb2 expression in osteoclasts in vivo, suggesting β-blockers may directly impact osteoclasts. Consistent with this, we found propranolol directly suppresses osteoclast differentiation in vitro. Taken together, this work suggests a strong anti-osteoclastic effect of nonselective β-blockers in vivo, indicating that combining propranolol with PTH could be beneficial to patients with extremely low bone density. © 2022 American Society for Bone and Mineral Research (ASBMR).
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Affiliation(s)
- Annika Treyball
- Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, ME, USA
| | - Audrey C Bergeron
- Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, ME, USA
| | - Daniel J Brooks
- Center for Advanced Orthopaedic Studies, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Audrie L Langlais
- Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, ME, USA.,Graduate School of Biomedical Sciences and Engineering, University of Maine, Orono, ME, USA
| | - Hina Hashmi
- Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, ME, USA
| | - Kenichi Nagano
- Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA, USA
| | - Deborah Barlow
- Department of Biomedical Sciences, University of New England, Biddeford, ME, USA
| | - Ryan J Neilson
- Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, ME, USA
| | - Tyler A Roy
- Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, ME, USA
| | - Kathleen T Nevola
- Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, ME, USA.,Tufts Graduate School of Biomedical Sciences, Tufts University, Boston, MA, USA
| | - Karen L Houseknecht
- Department of Biomedical Sciences, University of New England, Biddeford, ME, USA
| | - Roland Baron
- Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA, USA
| | - Mary L Bouxsein
- Center for Advanced Orthopaedic Studies, Beth Israel Deaconess Medical Center, Boston, MA, USA.,Department of Orthopedic Surgery, Harvard Medical School, Boston, MA, USA
| | - Anyonya R Guntur
- Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, ME, USA.,Graduate School of Biomedical Sciences and Engineering, University of Maine, Orono, ME, USA.,Tufts University School of Medicine, Tufts University, Boston, MA, USA
| | - Katherine J Motyl
- Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, ME, USA.,Graduate School of Biomedical Sciences and Engineering, University of Maine, Orono, ME, USA.,Tufts University School of Medicine, Tufts University, Boston, MA, USA
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2
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Lorenz MR, Brazill JM, Beeve AT, Shen I, Scheller EL. A Neuroskeletal Atlas: Spatial Mapping and Contextualization of Axon Subtypes Innervating the Long Bones of C3H and B6 Mice. J Bone Miner Res 2021; 36:1012-1025. [PMID: 33592122 PMCID: PMC8252627 DOI: 10.1002/jbmr.4273] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 02/05/2021] [Accepted: 02/11/2021] [Indexed: 12/14/2022]
Abstract
Nerves in bone play well-established roles in pain and vasoregulation and have been associated with progression of skeletal disorders, including osteoporosis, fracture, arthritis, and tumor metastasis. However, isolation of the region-specific mechanisms underlying these relationships is limited by our lack of quantitative methods for neuroskeletal analysis and precise maps of skeletal innervation. To overcome these limitations, we developed an optimized workflow for imaging and quantitative analysis of axons in and around the bone, including validation of Baf53b-Cre in concert with R26R-tdTomato (Ai9) as a robust pan-neuronal reporter system for use in musculoskeletal tissues. In addition, we created comprehensive maps of sympathetic adrenergic and sensory peptidergic axons within and around the full length of the femur and tibia in two strains of mice (B6 and C3H). In the periosteum, these maps were related to the surrounding musculature, including entheses and myotendinous attachments to bone. Three distinct patterns of periosteal innervation (termed type I, II, III) were defined at sites that are important for bone pain, bone repair, and skeletal homeostasis. For the first time, our results establish a gradient of bone marrow axon density that increases from proximal to distal along the length of the tibia and define key regions of interest for neuroskeletal studies. Lastly, this information was related to major nerve branches and local maps of specialized mechanoreceptors. This detailed mapping and contextualization of the axonal subtypes innervating the skeleton is intended to serve as a guide during the design, implementation, and interpretation of future neuroskeletal studies and was compiled as a resource for the field as part of the NIH SPARC consortium. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR)..
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Affiliation(s)
- Madelyn R Lorenz
- Division of Bone and Mineral Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Jennifer M Brazill
- Division of Bone and Mineral Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Alec T Beeve
- Division of Bone and Mineral Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA.,Department of Biomedical Engineering, Washington University, St. Louis, MO, USA
| | - Ivana Shen
- Division of Bone and Mineral Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Erica L Scheller
- Division of Bone and Mineral Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA.,Department of Biomedical Engineering, Washington University, St. Louis, MO, USA
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3
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Ma Y, Elefteriou F. Brain-Derived Acetylcholine Maintains Peak Bone Mass in Adult Female Mice. J Bone Miner Res 2020; 35:1562-1571. [PMID: 32282950 PMCID: PMC8087457 DOI: 10.1002/jbmr.4024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 03/20/2020] [Accepted: 03/31/2020] [Indexed: 12/26/2022]
Abstract
Preclinical and clinical data support a role of the sympathetic nervous system in the regulation of bone remodeling, but the contribution of parasympathetic arm of the autonomic nervous system to bone homeostasis remains less studied. In this study, we sought to determine whether acetylcholine (ACh) contributes to the regulation of bone remodeling after peak bone mass acquisition. We show that reduced central ACh synthesis in mice heterozygous for the choline transporter (ChT) leads to a decrease in bone mass in young female mice, thus independently confirming the previously reported beneficial effect of ACh signaling on bone mass accrual. Increasing brain ACh levels through the use of the blood brain barrier (BBB)-permeable acetylcholinesterase inhibitor (AChEI) galantamine increased trabecular bone mass in adult female mice, whereas a peripheral increase in ACh levels induced by the BBB-impermeable AChEI pyridostigmine caused trabecular bone loss. AChEIs did not alter skeletal norepinephrine level, and induced an overall increase in osteoblast and osteoclast densities, two findings that do not support a reduction in sympathetic outflow as the mechanism involved in the pro-anabolic effect of galantamine on the skeleton. In addition, we did not detect changes in the commitment of skeletal progenitor cells to the osteoblast lineage in vivo in AChEI-treated mice, nor a direct impact of these drugs in vitro on the survival and differentiation of osteoblast and osteoclast progenitors. Last, ChT heterozygosity and galantamine treatment triggered bone changes in female mice only, thus revealing the existence of a gender-specific skeletal response to brain ACh level. In conclusion, this study supports the stimulatory effect of central ACh on bone mass accrual, shows that it also promotes peak bone mass maintenance in adult mice, and suggests that central ACh regulates bone mass via different mechanisms in growing versus sexually mature mice. © 2020 American Society for Bone and Mineral Research.
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Affiliation(s)
- Yun Ma
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.,Department of Orthopedic Surgery, Baylor College of Medicine, Houston, TX, USA
| | - Florent Elefteriou
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.,Department of Orthopedic Surgery, Baylor College of Medicine, Houston, TX, USA
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Brazill JM, Beeve AT, Craft CS, Ivanusic JJ, Scheller EL. Nerves in Bone: Evolving Concepts in Pain and Anabolism. J Bone Miner Res 2019; 34:1393-1406. [PMID: 31247122 PMCID: PMC6697229 DOI: 10.1002/jbmr.3822] [Citation(s) in RCA: 90] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 05/28/2019] [Accepted: 06/18/2019] [Indexed: 12/21/2022]
Abstract
The innervation of bone has been described for centuries, and our understanding of its function has rapidly evolved over the past several decades to encompass roles of subtype-specific neurons in skeletal homeostasis. Current research has been largely focused on the distribution and function of specific neuronal populations within bone, as well as their cellular and molecular relationships with target cells in the bone microenvironment. This review provides a historical perspective of the field of skeletal neurobiology that highlights the diverse yet interconnected nature of nerves and skeletal health, particularly in the context of bone anabolism and pain. We explore what is known regarding the neuronal subtypes found in the skeleton, their distribution within bone compartments, and their central projection pathways. This neuroskeletal map then serves as a foundation for a comprehensive discussion of the neural control of skeletal development, homeostasis, repair, and bone pain. Active synthesis of this research recently led to the first biotherapeutic success story in the field. Specifically, the ongoing clinical trials of anti-nerve growth factor therapeutics have been optimized to titrated doses that effectively alleviate pain while maintaining bone and joint health. Continued collaborations between neuroscientists and bone biologists are needed to build on this progress, leading to a more complete understanding of neural regulation of the skeleton and development of novel therapeutics. © 2019 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals, Inc.
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Affiliation(s)
- Jennifer M Brazill
- Department of Internal Medicine, Division of Bone and Mineral Diseases, Washington University, St. Louis, MO, USA
| | - Alec T Beeve
- Department of Internal Medicine, Division of Bone and Mineral Diseases, Washington University, St. Louis, MO, USA.,Department of Biomedical Engineering, Washington University, St. Louis, MO, USA
| | - Clarissa S Craft
- Department of Internal Medicine, Division of Bone and Mineral Diseases, Washington University, St. Louis, MO, USA.,Department of Cell Biology and Physiology, Washington University, St. Louis, MO, USA
| | - Jason J Ivanusic
- Department of Anatomy and Neuroscience, University of Melbourne, Melbourne, Victoria, Australia
| | - Erica L Scheller
- Department of Internal Medicine, Division of Bone and Mineral Diseases, Washington University, St. Louis, MO, USA.,Department of Cell Biology and Physiology, Washington University, St. Louis, MO, USA
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Jardí F, Kim N, Laurent MR, Khalil R, Deboel L, Schollaert D, van Lenthe GH, Decallonne B, Carmeliet G, Claessens F, Vanderschueren D. Androgen Receptor in Neurons Slows Age-Related Cortical Thinning in Male Mice. J Bone Miner Res 2019; 34:508-519. [PMID: 30496619 DOI: 10.1002/jbmr.3625] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 10/30/2018] [Accepted: 11/05/2018] [Indexed: 12/26/2022]
Abstract
Androgens via the androgen receptor (AR) are required for optimal male bone health. The target cell(s) for the effects of androgens on cortical bone remain(s) incompletely understood. In females, estrogen receptor alpha in neurons is a negative regulator of cortical and trabecular bone. Whether neuronal AR regulates bone mass in males remains unexplored. Here, we inactivated AR in neurons using a tamoxifen-inducible CreERT2 under the control of the neuronal promoter Thy1. Tamoxifen induced a 70% to 80% reduction of AR mRNA levels in Thy1-CreERT2-positive brain regions cerebral cortex and brainstem as well as in the peripheral nervous tissue of male neuronal AR knockout (N-ARKO) mice. Hypothalamic AR mRNA levels were only marginally reduced and the hypothalamic-pituitary-gonadal axis remained unaffected, as determined by normal levels of serum testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH). In contrast to orchidectomy, deletion of neuronal AR did not alter body weight, body composition, hindlimb muscle mass, grip strength, or wheel running. MicroCT analysis of the femur revealed no changes in bone accrual during growth in N-ARKO mice. However, 36- and 46-week-old N-ARKO mice displayed an accelerated age-related cortical involution, namely a more pronounced loss of cortical thickness and strength, which occurred in the setting of androgen sufficiency. Neuronal AR inactivation decreased the cancellous bone volume fraction in L5 vertebra but not in the appendicular skeleton of aging mice. MicroCT findings were corroborated in the tibia and after normalization of hormonal levels. Serum markers of bone turnover and histomorphometry parameters were comparable between genotypes, except for a 30% increase in osteoclast surface in the trabecular compartment of 36-week-old N-ARKO mice. Cortical bone loss in N-ARKO mice was associated with an upregulation of Ucp1 expression in brown adipose tissue, a widely used readout for sympathetic tone. We conclude that androgens preserve cortical integrity in aging male mice via AR in neurons. © 2018 American Society for Bone and Mineral Research.
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Affiliation(s)
- Ferran Jardí
- Clinical and Experimental Endocrinology, Department of Chronic Diseases, Metabolism and Aging (CHROMETA), KU Leuven, Leuven, Belgium
| | - Nari Kim
- Clinical and Experimental Endocrinology, Department of Chronic Diseases, Metabolism and Aging (CHROMETA), KU Leuven, Leuven, Belgium
| | - Michaël R Laurent
- Molecular Endocrinology Laboratory, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium.,Gerontology and Geriatrics, Department of Chronic Diseases, Metabolism and Aging (CHROMETA), KU Leuven, Leuven, Belgium
| | - Rougin Khalil
- Clinical and Experimental Endocrinology, Department of Chronic Diseases, Metabolism and Aging (CHROMETA), KU Leuven, Leuven, Belgium
| | - Ludo Deboel
- Clinical and Experimental Endocrinology, Department of Chronic Diseases, Metabolism and Aging (CHROMETA), KU Leuven, Leuven, Belgium
| | - Dieter Schollaert
- Clinical and Experimental Endocrinology, Department of Chronic Diseases, Metabolism and Aging (CHROMETA), KU Leuven, Leuven, Belgium
| | - G H van Lenthe
- Biomechanics Section, Department of Mechanical Engineering, KU Leuven, Leuven, Belgium
| | - Brigitte Decallonne
- Clinical and Experimental Endocrinology, Department of Chronic Diseases, Metabolism and Aging (CHROMETA), KU Leuven, Leuven, Belgium
| | - Geert Carmeliet
- Clinical and Experimental Endocrinology, Department of Chronic Diseases, Metabolism and Aging (CHROMETA), KU Leuven, Leuven, Belgium
| | - Frank Claessens
- Molecular Endocrinology Laboratory, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Dirk Vanderschueren
- Clinical and Experimental Endocrinology, Department of Chronic Diseases, Metabolism and Aging (CHROMETA), KU Leuven, Leuven, Belgium
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Pan KS, Heiss JD, Brown SM, Collins MT, Boyce AM. Chiari I Malformation and Basilar Invagination in Fibrous Dysplasia: Prevalence, Mechanisms, and Clinical Implications. J Bone Miner Res 2018; 33:1990-1998. [PMID: 29924878 PMCID: PMC6218312 DOI: 10.1002/jbmr.3531] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2018] [Revised: 06/08/2018] [Accepted: 06/17/2018] [Indexed: 01/22/2023]
Abstract
Fibrous dysplasia (FD) is a mosaic disorder of benign fibro-osseous lesions, which may be associated with extraskeletal features as part of McCune-Albright syndrome (MAS). Cranial base abnormalities, including Chiari I malformation (CM1), in which the cerebellum extends below the foramen magnum, and secondary basilar invagination (BI), in which the odontoid prolapses into the posterior cranial fossa, are potentially serious complications of metabolic bone disorders. The purpose of this study was to determine the prevalence, natural history, and risk factors for CM1 and BI in patients with FD/MAS, and to determine mechanisms of cranial base deformities. Clinical and radiographic data from subjects in an FD/MAS natural history study were evaluated and compared to normal controls. In 158 patients with craniofacial FD, 10 (6.3%) cases of CM1 and 12 (7.6%) cases of BI were diagnosed. No cranial base abnormalities were identified in 10 control subjects. Craniomorphometric and volumetric analyses identified cranial constriction and cranial settling as the primary mechanisms of cranial base abnormalities, whereas intracranial hypertension was a contributing factor in a minority of subjects. Longitudinal analyses found progression of odontoid position with age, but no progression of tonsillar position. No endocrinopathies were associated with CM1. MAS endocrinopathies associated with BI included hyperthyroidism (odds ratio [OR] 12.0; 95% confidence interval [CI], 2.9 to 55.6; p < 0.01), precocious puberty (OR 5.6; 95% CI, 1.2 to 26.0; p < 0.05), and hypophosphatemia (OR 7.7; 95% CI, 1.9 to 27.0; p < 0.01). Scoliosis was associated with both CM1 (OR 4.8; 95% CI, 1.1 to 22.8; p < 0.05) and BI (OR = infinity; 95% CI, 4.7 to infinity; p < 0.01). This study successfully characterized cranial base abnormalities in FD/MAS and the pathophysiological connection between them. These findings support routine screening for cranial base abnormalities in patients with craniofacial FD, as well as aggressive management of contributory risk factors. © 2018 American Society for Bone and Mineral Research.
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Affiliation(s)
- Kristen S Pan
- Skeletal Disorders and Mineral Homeostasis Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, USA
| | - John D Heiss
- Surgical Neurology Branch, National Institute of Neurologic Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Sydney M Brown
- Skeletal Disorders and Mineral Homeostasis Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, USA
| | - Michael T Collins
- Skeletal Disorders and Mineral Homeostasis Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, USA
| | - Alison M Boyce
- Skeletal Disorders and Mineral Homeostasis Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, USA
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Calarge CA, Butcher BD, Burns TL, Coryell WH, Schlechte JA, Zemel BS. Major depressive disorder and bone mass in adolescents and young adults. J Bone Miner Res 2014; 29:2230-7. [PMID: 24723424 PMCID: PMC5520808 DOI: 10.1002/jbmr.2249] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Revised: 03/26/2014] [Accepted: 03/28/2014] [Indexed: 01/13/2023]
Abstract
Depression has been associated with reduced bone mass in adults, but the mechanisms remain unclear. In addition, little is known about the association between depression and bone health during growth and development. To address this knowledge gap, we examined bone density and structure in 222 adolescents and young adults (69% females, mean ± SD age: 19.0 ± 1.5 years), enrolled within 1 month of starting a selective serotonin reuptake inhibitor (SSRI) or unmedicated. Psychiatric functioning was assessed with self-report and researcher-administered instruments, including the Longitudinal Interval Follow-up Evaluation for Adolescents (A-LIFE). Anthropometric and laboratory measures included dual-energy x-ray absorptiometry and peripheral quantitative computed tomography scans. Linear multivariable regression analysis tested the association between depression and bone mass, after accounting for relevant confounders. The presence of current depression was associated with a significant reduction in age-sex-height-race-specific bone mineral density (BMD) and content (BMC) of total body less head and lumbar spine. The findings varied by assessment method with self-report scales, capturing symptom severity over the prior week or two, yielding the weakest associations. Depression was also associated with reduced cortical thickness and a trend for increased endosteal circumference. In contrast, generalized anxiety disorder was not associated with bone deficits. In sum, depressive illness is associated with significantly lower bone mass in youths. Future investigations must examine whether bone recovery is possible following depression remission or whether remedial interventions are warranted to optimize bone mass in order to minimize the long-term risk of osteoporosis.
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Affiliation(s)
- Chadi A. Calarge
- Departments of Psychiatry and Pediatrics, The University of Iowa
| | | | - Trudy L. Burns
- Departments of Epidemiology and Pediatrics, The University of Iowa
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Baldock PA, Lin S, Zhang L, Karl T, Shi Y, Driessler F, Zengin A, Hörmer B, Lee NJ, Wong IPL, Lin EJD, Enriquez RF, Stehrer B, During MJ, Yulyaningsih E, Zolotukhin S, Ruohonen ST, Savontaus E, Sainsbury A, Herzog H. Neuropeptide y attenuates stress-induced bone loss through suppression of noradrenaline circuits. J Bone Miner Res 2014; 29:2238-49. [PMID: 24535841 DOI: 10.1002/jbmr.2205] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Revised: 02/09/2014] [Accepted: 02/12/2014] [Indexed: 12/23/2022]
Abstract
Chronic stress and depression have adverse consequences on many organ systems, including the skeleton, but the mechanisms underlying stress-induced bone loss remain unclear. Here we demonstrate that neuropeptide Y (NPY), centrally and peripherally, plays a critical role in protecting against stress-induced bone loss. Mice lacking the anxiolytic factor NPY exhibit more anxious behavior and elevated corticosterone levels. Additionally, following a 6-week restraint, or cold-stress protocol, Npy-null mice exhibit three-fold greater bone loss compared to wild-type mice, owing to suppression of osteoblast activity. This stress-protective NPY pathway acts specifically through Y2 receptors. Centrally, Y2 receptors suppress corticotropin-releasing factor expression and inhibit activation of noradrenergic neurons in the paraventricular nucleus. In the periphery, they act to control noradrenaline release from sympathetic neurons. Specific deletion of arcuate Y2 receptors recapitulates the Npy-null stress response, coincident with elevated serum noradrenaline. Importantly, specific reintroduction of NPY solely in noradrenergic neurons of otherwise Npy-null mice blocks the increase in circulating noradrenaline and the stress-induced bone loss. Thus, NPY protects against excessive stress-induced bone loss, through Y2 receptor-mediated modulation of central and peripheral noradrenergic neurons.
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Affiliation(s)
- P A Baldock
- Neurological Disease Division, Garvan Institute of Medical Research, St Vincent's Hospital, Sydney, Australia; Osteoporosis and Bone Biology Division, Garvan Institute of Medical Research, St Vincent's Hospital, Sydney, Australia; Faculty of Medicine, University of New South Wales, Sydney, Australia
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