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Carina V, Della Bella E, Costa V, Bellavia D, Veronesi F, Cepollaro S, Fini M, Giavaresi G. Bone's Response to Mechanical Loading in Aging and Osteoporosis: Molecular Mechanisms. Calcif Tissue Int 2020; 107:301-318. [PMID: 32710266 DOI: 10.1007/s00223-020-00724-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 07/08/2020] [Indexed: 02/07/2023]
Abstract
Mechanotransduction is pivotal in the maintenance of homeostasis in different tissues and involves multiple cell signaling pathways. In bone, mechanical stimuli regulate the balance between bone formation and resorption; osteocytes play a central role in this regulation. Dysfunctions in mechanotransduction signaling or in osteocytes response lead to an imbalance in bone homeostasis. This alteration is very relevant in some conditions such as osteoporosis and aging. Both are characterized by increased bone weakness due to different causes, for example, the increase of osteocyte apoptosis that cause an alteration of fluid space, or the alteration of molecular pathways. There are intertwined yet very different mechanisms involved among the cell-intrinsic effects of aging on bone, the cell-intrinsic and tissue-level effects of estrogen/androgen withdrawal on bone, and the effects of reduced mechanical loading on bone, which are all involved to some degree in how aged bone fails to respond properly to stress/strain compared to younger bone. This review aims at clarifying how the cellular and molecular pathways regulated and induced in bone by mechanical stimulation are altered with aging and in osteoporosis, to highlight new possible targets for antiresorptive or anabolic bone therapeutic approaches.
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Affiliation(s)
- Valeria Carina
- IRCCS Istituto Ortopedico Rizzoli, SC Scienze e Tecnologie Chirurgiche - SS Piattaforma Scienze Omiche per Ortopedia Personalizzata, Via Di Barbiano, 1/10, 40136, Bologna, Italy.
| | | | - Viviana Costa
- IRCCS Istituto Ortopedico Rizzoli, SC Scienze e Tecnologie Chirurgiche - SS Piattaforma Scienze Omiche per Ortopedia Personalizzata, Via Di Barbiano, 1/10, 40136, Bologna, Italy
| | - Daniele Bellavia
- IRCCS Istituto Ortopedico Rizzoli, SC Scienze e Tecnologie Chirurgiche - SS Piattaforma Scienze Omiche per Ortopedia Personalizzata, Via Di Barbiano, 1/10, 40136, Bologna, Italy
| | - Francesca Veronesi
- IRCCS Istituto Ortopedico Rizzoli, SC Scienze e Tecnologie Chirurgiche - SS Piattaforma Scienze Omiche per Ortopedia Personalizzata, Via Di Barbiano, 1/10, 40136, Bologna, Italy
| | - Simona Cepollaro
- IRCCS Istituto Ortopedico Rizzoli, SC Scienze e Tecnologie Chirurgiche - SS Piattaforma Scienze Omiche per Ortopedia Personalizzata, Via Di Barbiano, 1/10, 40136, Bologna, Italy
| | - Milena Fini
- IRCCS Istituto Ortopedico Rizzoli, SC Scienze e Tecnologie Chirurgiche - SS Piattaforma Scienze Omiche per Ortopedia Personalizzata, Via Di Barbiano, 1/10, 40136, Bologna, Italy
| | - Gianluca Giavaresi
- IRCCS Istituto Ortopedico Rizzoli, SC Scienze e Tecnologie Chirurgiche - SS Piattaforma Scienze Omiche per Ortopedia Personalizzata, Via Di Barbiano, 1/10, 40136, Bologna, Italy
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Laurent MR, Jardí F, Dubois V, Schollaert D, Khalil R, Gielen E, Carmeliet G, Claessens F, Vanderschueren D. Androgens have antiresorptive effects on trabecular disuse osteopenia independent from muscle atrophy. Bone 2016; 93:33-42. [PMID: 27622887 DOI: 10.1016/j.bone.2016.09.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Revised: 09/07/2016] [Accepted: 09/09/2016] [Indexed: 12/18/2022]
Abstract
Aging hypogonadal men are at increased risk of osteoporosis and sarcopenia. Testosterone is a potentially appealing strategy to prevent simultaneous bone and muscle loss. The androgen receptor (AR) mediates antiresorptive effects on trabecular bone via osteoblast-lineage cells, as well as muscle-anabolic actions. Sex steroids also modify the skeletal response to mechanical loading. However, it is unclear whether the effects of androgens on bone remain effective independent of mechanical stimulation or rather require indirect androgen effects via muscle. This study aims to characterize the effects and underlying mechanisms of androgens on disuse osteosarcopenia. Adult male mice received a unilateral botulinum toxin (BTx) injection, and underwent sham surgery or orchidectomy (ORX) without or with testosterone (ORX+T) or dihydrotestosterone (ORX+DHT) replacement. Compared to the contralateral internal control hindlimb, acute trabecular number and bone volume loss was increased by ORX and partially prevented DHT. T was more efficient and increased BV/TV in both hindlimbs over sham values, although it did not reduce the detrimental effect of BTx. Both androgens and BTx regulated trabecular osteoclast surface as well as tartrate-resistant acid phosphatase expression. Androgens also prevented BTx-induced body weight loss but did not significantly influence paralysis or muscle atrophy. BTx and ORX both reduced cortical thickness via endosteal expansion, which was prevented by T but not DHT. In long-term follow-up, the residual trabecular bone volume deficit in sham-BTx hindlimbs was prevented by DHT but T restored it more efficiently to pre-treatment levels. Conditional AR deletion in late osteoblasts and osteocytes or in the satellite cell lineage increased age-related trabecular bone loss in both hindlimbs without influencing the effect of BTx on trabecular osteopenia. We conclude that androgens have antiresorptive effects on trabecular disuse osteopenia which do not require AR actions on bone via muscle or via osteocytes.
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MESH Headings
- Acute Disease
- Androgens/pharmacology
- Androgens/therapeutic use
- Animals
- Body Weight
- Bone Diseases, Metabolic/complications
- Bone Diseases, Metabolic/drug therapy
- Bone Diseases, Metabolic/pathology
- Bone Diseases, Metabolic/physiopathology
- Bone Remodeling/drug effects
- Bone Resorption/complications
- Bone Resorption/drug therapy
- Bone Resorption/pathology
- Bone Resorption/physiopathology
- Calcification, Physiologic
- Cancellous Bone/diagnostic imaging
- Cancellous Bone/drug effects
- Cancellous Bone/pathology
- Cancellous Bone/physiopathology
- Cortical Bone/diagnostic imaging
- Cortical Bone/drug effects
- Cortical Bone/pathology
- Cortical Bone/physiopathology
- Extracellular Matrix Proteins/metabolism
- Female
- Gene Deletion
- Integrases/metabolism
- Male
- Mice, Inbred C57BL
- Muscular Atrophy/complications
- Muscular Atrophy/drug therapy
- Muscular Atrophy/pathology
- Muscular Atrophy/physiopathology
- Muscular Disorders, Atrophic/complications
- Muscular Disorders, Atrophic/drug therapy
- Muscular Disorders, Atrophic/pathology
- Muscular Disorders, Atrophic/physiopathology
- MyoD Protein/metabolism
- Organ Size
- Receptors, Androgen/metabolism
- X-Ray Microtomography
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Affiliation(s)
- Michaël R Laurent
- Laboratory of Molecular Endocrinology, Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49, PO box 901, 3000 Leuven, Belgium; Gerontology and Geriatrics, Department of Clinical and Experimental Medicine, KU Leuven, Herestraat 49, PO box 7003, 3000 Leuven, Belgium; Center for Metabolic Bone Diseases, University Hospitals Leuven, Herestraat 49, 3000 Leuven, Belgium.
| | - Ferran Jardí
- Clinical and Experimental Endocrinology, Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49, PO box 902, 3000 Leuven, Belgium.
| | - Vanessa Dubois
- Laboratory of Molecular Endocrinology, Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49, PO box 901, 3000 Leuven, Belgium.
| | - Dieter Schollaert
- Laboratory of Molecular Endocrinology, Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49, PO box 901, 3000 Leuven, Belgium.
| | - Rougin Khalil
- Clinical and Experimental Endocrinology, Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49, PO box 902, 3000 Leuven, Belgium.
| | - Evelien Gielen
- Gerontology and Geriatrics, Department of Clinical and Experimental Medicine, KU Leuven, Herestraat 49, PO box 7003, 3000 Leuven, Belgium; Center for Metabolic Bone Diseases, University Hospitals Leuven, Herestraat 49, 3000 Leuven, Belgium.
| | - Geert Carmeliet
- Clinical and Experimental Endocrinology, Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49, PO box 902, 3000 Leuven, Belgium.
| | - Frank Claessens
- Laboratory of Molecular Endocrinology, Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49, PO box 901, 3000 Leuven, Belgium.
| | - Dirk Vanderschueren
- Clinical and Experimental Endocrinology, Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49, PO box 902, 3000 Leuven, Belgium.
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Yarrow JF, Conover CF, Beggs LA, Beck DT, Otzel DM, Balaez A, Combs SM, Miller JR, Ye F, Aguirre JI, Neuville KG, Williams AA, Conrad BP, Gregory CM, Wronski TJ, Bose PK, Borst SE. Testosterone dose dependently prevents bone and muscle loss in rodents after spinal cord injury. J Neurotrauma 2014; 31:834-45. [PMID: 24378197 DOI: 10.1089/neu.2013.3155] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Androgen administration protects against musculoskeletal deficits in models of sex-steroid deficiency and injury/disuse. It remains unknown, however, whether testosterone prevents bone loss accompanying spinal cord injury (SCI), a condition that results in a near universal occurrence of osteoporosis. Our primary purpose was to determine whether testosterone-enanthate (TE) attenuates hindlimb bone loss in a rodent moderate/severe contusion SCI model. Forty (n=10/group), 14 week old male Sprague-Dawley rats were randomized to receive: (1) Sham surgery (T9 laminectomy), (2) moderate/severe (250 kdyne) SCI, (3) SCI+Low-dose TE (2.0 mg/week), or (4) SCI+High-dose TE (7.0 mg/week). Twenty-one days post-injury, SCI animals exhibited a 77-85% reduction in hindlimb cancellous bone volume at the distal femur (measured via μCT) and proximal tibia (measured via histomorphometry), characterized by a >70% reduction in trabecular number, 13-27% reduction in trabecular thickness, and increased trabecular separation. A 57% reduction in cancellous volumetric bone mineral density (vBMD) at the distal femur and a 20% reduction in vBMD at the femoral neck were also observed. TE dose dependently prevented hindlimb bone loss after SCI, with high-dose TE fully preserving cancellous bone structural characteristics and vBMD at all skeletal sites examined. Animals receiving SCI also exhibited a 35% reduction in hindlimb weight bearing (triceps surae) muscle mass and a 22% reduction in sublesional non-weight bearing (levator ani/bulbocavernosus [LABC]) muscle mass, and reduced prostate mass. Both TE doses fully preserved LABC mass, while only high-dose TE ameliorated hindlimb muscle losses. TE also dose dependently increased prostate mass. Our findings provide the first evidence indicating that high-dose TE fully prevents hindlimb cancellous bone loss and concomitantly ameliorates muscle loss after SCI, while low-dose TE produces much less profound musculoskeletal benefit. Testosterone-induced prostate enlargement, however, represents a potential barrier to the clinical implementation of high-dose TE as a means of preserving musculoskeletal tissue after SCI.
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Affiliation(s)
- Joshua F Yarrow
- 1 VA Medical Center, Research Service, VA Medical Center , Gainesville, Florida
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Sun L, Pan J, Peng Y, Wu Y, Li J, Liu X, Qin Y, Bauman WA, Cardozo C, Zaidi M, Qin W. Anabolic steroids reduce spinal cord injury-related bone loss in rats associated with increased Wnt signaling. J Spinal Cord Med 2013; 36:616-22. [PMID: 24090150 PMCID: PMC3831322 DOI: 10.1179/2045772312y.0000000020] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND Spinal cord injury (SCI) causes severe bone loss. At present, there is no practical treatment to delay or prevent bone loss in individuals with motor-complete SCI. Hypogonadism is common in men after SCI and may exacerbate bone loss. The anabolic steroid nandrolone reduces bone loss due to microgravity or nerve transection. OBJECTIVE To determine whether nandrolone reduced bone loss after SCI and, if so, to explore the mechanisms of nandrolone action. METHODS Male rats with complete transection of the spinal cord were administered nandrolone combined with a physiological replacement dose of testosterone, or vehicle, beginning on day 29 after SCI and continued for 28 days. RESULTS SCI reduced distal femoral and proximal tibial bone mineral density (BMD) by 25 and 16%, respectively, at 56 days. This bone loss was attenuated by nandrolone. In ex vivo osteoclasts cultures, SCI increased mRNA levels for tartrate-resistant acid phosphatase (TRAP) and calcitonin receptor; nandrolone-normalized expression levels of these transcripts. In ex vivo osteoblast cultures, SCI increased receptor activator of NF-kB ligand (RANKL) mRNA levels but did not alter osteoprotegerin (OPG) mRNA expression; nandrolone-increased expression of OPG and OPG/RANKL ratio. SCI reduced mRNA levels of Wnt signaling-related genes Wnt3a, low-density lipoprotein receptor-related protein 5 (LRP5), Fzd5, Tcf7, and ectodermal-neural cortex 1 (ENC1) in osteoblasts, whereas nandrolone increased expression of each of these genes. CONCLUSIONS The results demonstrate that nandrolone reduces bone loss after SCI. A potential mechanism is suggested by our findings wherein nandrolone modulates genes for differentiation and activity of osteoclasts and osteoblasts, at least in part, through the activation of Wnt signaling.
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Affiliation(s)
- Li Sun
- Mount Sinai Bone Program, Mount Sinai School of Medicine, New York, NY, USA
| | - Jiangping Pan
- Center of Excellence for the Medical Consequences of SCI, James J. Peters VA Medical Center, Bronx, NY, USA
| | - Yuanzhen Peng
- Mount Sinai Bone Program, Mount Sinai School of Medicine, New York, NY, USA
| | - Yong Wu
- Center of Excellence for the Medical Consequences of SCI, James J. Peters VA Medical Center, Bronx, NY, USA
| | - Jianghua Li
- Mount Sinai Bone Program, Mount Sinai School of Medicine, New York, NY, USA
| | - Xuan Liu
- Mount Sinai Bone Program, Mount Sinai School of Medicine, New York, NY, USA
| | - Yiwen Qin
- Center of Excellence for the Medical Consequences of SCI, James J. Peters VA Medical Center, Bronx, NY, USA
| | - William A. Bauman
- Center of Excellence for the Medical Consequences of SCI, James J. Peters VA Medical Center, Bronx, NY, USA; Department of Medicine, Mount Sinai School of Medicine, New York, NY, USA; and Department of Rehabilitation Medicine, Mount Sinai School of Medicine, New York, NY, USA
| | - Christopher Cardozo
- Center of Excellence for the Medical Consequences of SCI, James J. Peters VA Medical Center, Bronx, NY, USA; Department of Medicine, Mount Sinai School of Medicine, New York, NY, USA; and Department of Rehabilitation Medicine, Mount Sinai School of Medicine, New York, NY, USA
| | - Mone Zaidi
- Mount Sinai Bone Program, Mount Sinai School of Medicine, New York, NY, USA
| | - Weiping Qin
- Center of Excellence for the Medical Consequences of SCI, James J. Peters VA Medical Center, Bronx, NY, USA; and Department of Medicine, Mount Sinai School of Medicine, New York, NY, USA,Correspondence to: Weiping Qin, James J. Peters VA Medical Center, 130 West Kingsbridge Road, Bronx, NY 10468, USA.
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