1
|
Yocom A, Contino E, Kawcak C. Review of the Mechanism of Action and Use of Bisphosphonates in Horses. J Equine Vet Sci 2023:104503. [PMID: 37120118 DOI: 10.1016/j.jevs.2023.104503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 04/13/2023] [Accepted: 04/24/2023] [Indexed: 05/01/2023]
Abstract
Bisphosphonates are a group of drugs that can reduce bone resorption by incorporating into the crystal structure of exposed hydroxyapatite where they are taken up by osteoclasts. Bisphosphonates have several other mechanisms of action including reducing pain and inflammation and altering macrophage function. There are two types of bisphosphonates - nitrogenous and non-nitrogenous, the latter of which is used in horses. This article provides a literature-based review of the proposed mechanisms of action and therapeutic uses of bisphosphonates including a brief review of bone response to disease. A review of the literature available in horses including safety data and current rules and regulations is also provided.
Collapse
Affiliation(s)
- Alicia Yocom
- Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, 300 West Drake Road, Fort Collins, CO 80523
| | - Erin Contino
- Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, 300 West Drake Road, Fort Collins, CO 80523
| | - Christopher Kawcak
- Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, 300 West Drake Road, Fort Collins, CO 80523.
| |
Collapse
|
2
|
Bone adaptation and osteoporosis prevention in hibernating mammals. Comp Biochem Physiol A Mol Integr Physiol 2023; 280:111411. [PMID: 36871815 DOI: 10.1016/j.cbpa.2023.111411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 02/26/2023] [Accepted: 02/28/2023] [Indexed: 03/06/2023]
Abstract
Hibernating bears and rodents have evolved mechanisms to prevent disuse osteoporosis during the prolonged physical inactivity that occurs during hibernation. Serum markers and histological indices of bone remodeling in bears indicate reduced bone turnover during hibernation, which is consistent with organismal energy conservation. Calcium homeostasis is maintained by balanced bone resorption and formation since hibernating bears do not eat, drink, urinate, or defecate. Reduced and balanced bone remodeling protect bear bone structure and strength during hibernation, unlike the disuse osteoporosis that occurs in humans and other animals during prolonged physical inactivity. Conversely, some hibernating rodents show varying degrees of bone loss such as osteocytic osteolysis, trabecular loss, and cortical thinning. However, no negative effects of hibernation on bone strength in rodents have been found. More than 5000 genes in bear bone tissue are differentially expressed during hibernation, highlighting the complexity of hibernation induced changes in bone. A complete picture of the mechanisms that regulate bone metabolism in hibernators still alludes us, but existing data suggest a role for endocrine and paracrine factors such as cocaine- and amphetamine-regulated transcript (CART) and endocannabinoid ligands like 2-arachidonoyl glycerol (2-AG) in decreasing bone remodeling during hibernation. Hibernating bears and rodents evolved the capacity to preserve bone strength during long periods of physical inactivity, which contributes to their survival and propagation by allowing physically activity (foraging, escaping predators, and mating) without risk of bone fracture following hibernation. Understanding the biological mechanisms regulating bone metabolism in hibernators may inform novel treatment strategies for osteoporosis in humans.
Collapse
|
3
|
Abstract
Disuse osteoporosis describes a state of bone loss due to local skeletal unloading or systemic immobilization. This review will discuss advances in the field that have shed light on clinical observations, mechanistic insights and options for the treatment of disuse osteoporosis. Clinical settings of disuse osteoporosis include spinal cord injury, other neurological and neuromuscular disorders, immobilization after fractures and bed rest (real or modeled). Furthermore, spaceflight-induced bone loss represents a well-known adaptive process to microgravity. Clinical studies have outlined that immobilization leads to immediate bone loss in both the trabecular and cortical compartments accompanied by relatively increased bone resorption and decreased bone formation. The fact that the low bone formation state has been linked to high levels of the osteocyte-secreted protein sclerostin is one of the many findings that has brought matrix-embedded, mechanosensitive osteocytes into focus in the search for mechanistic principles. Previous basic research has primarily involved rodent models based on tail suspension, spaceflight and other immobilization methods, which have underlined the importance of osteocytes in the pathogenesis of disuse osteoporosis. Furthermore, molecular-based in vitro and in vivo approaches have revealed that osteocytes sense mechanical loading through mechanosensors that translate extracellular mechanical signals to intracellular biochemical signals and regulate gene expression. Osteocytic mechanosensors include the osteocyte cytoskeleton and dendritic processes within the lacuno-canalicular system (LCS), ion channels (e.g., Piezo1), extracellular matrix, primary cilia, focal adhesions (integrin-based) and hemichannels and gap junctions (connexin-based). Overall, disuse represents one of the major factors contributing to immediate bone loss and osteoporosis, and alterations in osteocytic pathways appear crucial to the bone loss associated with unloading.
Collapse
Affiliation(s)
- Tim Rolvien
- Division of Orthopaedics, Department of Trauma and Orthopaedic Surgery, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany.
| | - Michael Amling
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Lottestrasse 59, 22529, Hamburg, Germany.
| |
Collapse
|
4
|
Xu M, Du J, Cui J, Zhang S, Zhang S, Deng M, Zhang W, Li H, Yu Z. Cell-Free Fat Extract Prevents Tail Suspension–Induced Bone Loss by Inhibiting Osteocyte Apoptosis. Front Bioeng Biotechnol 2022; 10:818572. [PMID: 35174144 PMCID: PMC8842243 DOI: 10.3389/fbioe.2022.818572] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 01/03/2022] [Indexed: 11/13/2022] Open
Abstract
Introduction: As the space field has developed and our population ages, people engaged in space travel and those on prolonged bed rest are at increasing risk for bone loss and fractures. Disuse osteoporosis occurs frequently in these instances, for which the currently available anti-osteoporosis agents are far from satisfactory and have undesirable side effects. CEFFE is a cell-free fraction isolated from nanofat that is enriched with a variety of growth factors, and we aim to investigate its potential therapeutic effects on disuse osteoporosis. Methods: A tail suspension–induced osteoporosis model was applied in this study. Three weeks after tail suspension, CEFFE was intraperitoneally injected, and PBS was used as a control. The trabecular and cortical bone microstructures of the tibia in each group were assessed by μCT after 4 weeks of administration. Osteocyte lacunar-canalicularity was observed by HE and silver staining. In vitro, MLO-Y4 cell apoptosis was induced by reactive oxygen species (ROSUP). TUNEL staining and flow cytometry were used to detect apoptosis. CCK-8 was used to detect cell proliferation, and Western blotting was used to detect MAPK signaling pathway changes. Results: CEFFE increased the bone volume (BV/TV) and trabecular number (Tb.N) of the trabecular bone and increased the thickness of the cortical bone. HE and silver staining results showed that CEFFE reduced the number of empty lacunae and improved the lacuna-canalicular structure. CEFFE promoted osteocyte proliferative capacity in a dose-dependent manner. CEFFE protected MLO-Y4 from apoptosis by activating the serine/threonine-selective protein kinase (ERK) signaling pathways. Conclusion: CEFFE attenuated immobilization-induced bone loss by decreasing osteocyte apoptosis. CEFFE increased the survival of osteocytes and inhibited osteocyte apoptosis by activating the ERK signaling pathway in vitro.
Collapse
Affiliation(s)
- Mingming Xu
- Shanghai Key Laboratory of Orthopedic Implants, Department of Orthopedic Surgery, Shanghai Ninth Peoples Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jingke Du
- Shanghai Key Laboratory of Orthopedic Implants, Department of Orthopedic Surgery, Shanghai Ninth Peoples Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Knee Surgery Department of the Institute of Sports Medicine, Beijing Key Laboratory of Sports Injuries, Peking University Third Hospital, Beijing, China
| | - Junqi Cui
- Department of Pathology, Shanghai Ninth Peoples Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Shuangyan Zhang
- Shanghai Key Laboratory of Orthopedic Implants, Department of Orthopedic Surgery, Shanghai Ninth Peoples Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Shuhong Zhang
- Shanghai Key Laboratory of Orthopedic Implants, Department of Orthopedic Surgery, Shanghai Ninth Peoples Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Mingwu Deng
- Shanghai Key Laboratory of Tissue Engineering, Department of Plastic and Reconstructive Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Wenjie Zhang
- Shanghai Key Laboratory of Tissue Engineering, Department of Plastic and Reconstructive Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Hanjun Li
- Shanghai Key Laboratory of Orthopedic Implants, Department of Orthopedic Surgery, Shanghai Ninth Peoples Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Clinical Stem Cell Research Center, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- *Correspondence: Hanjun Li, ; Zhifeng Yu,
| | - Zhifeng Yu
- Shanghai Key Laboratory of Orthopedic Implants, Department of Orthopedic Surgery, Shanghai Ninth Peoples Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- *Correspondence: Hanjun Li, ; Zhifeng Yu,
| |
Collapse
|
5
|
Bauman WA. Pharmacological approaches for bone health in persons with spinal cord injury. Curr Opin Pharmacol 2021; 60:346-359. [PMID: 34534754 DOI: 10.1016/j.coph.2021.07.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 07/26/2021] [Accepted: 07/28/2021] [Indexed: 10/20/2022]
Abstract
Spinal cord injury (SCI) results in rapid, marked skeletal deterioration below the level of neurological lesion. Ideally, the most effective therapeutic approach would prevent loss of bone mass and architecture shortly after paralysis. Bisphosphonates preserve bone mineral density at the hip but not at the knee, which is the anatomical site most prone to fracture in the SCI population. Denosumab has recently been reported to prevent bone loss in persons with acute SCI but should be continued for an as yet indeterminate time because discontinuation will result in rapid bone loss. Several other novel approaches to preserving bone at the time of acute SCI should be tested, as well as approaches to reverse bone loss in individuals with chronic SCI.
Collapse
Affiliation(s)
- William A Bauman
- Department of Veterans Affairs Rehabilitation Research & Development Service National Center for the Medical Consequences of Spinal Cord Injury, James J. Peters Veterans Affairs Medical Center, Bronx, NY, USA; Internal Medical Service, James J. Peters VA Medical Center, Bronx, NY, USA; Departments of Medicine & Rehabilitation and Human Performance, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
| |
Collapse
|
6
|
Transcriptional changes and preservation of bone mass in hibernating black bears. Sci Rep 2021; 11:8281. [PMID: 33859306 PMCID: PMC8050052 DOI: 10.1038/s41598-021-87785-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 04/05/2021] [Indexed: 11/19/2022] Open
Abstract
Physical inactivity leads to losses of bone mass and strength in most mammalian species. In contrast, hibernating bears show no bone loss over the prolonged periods (4–6 months) of immobility during winter, which suggests that they have adaptive mechanisms to preserve bone mass. To identify transcriptional changes that underlie molecular mechanisms preventing disuse osteoporosis, we conducted a large-scale gene expression screening in the trabecular bone and bone marrow, comparing hibernating and summer active bears through sequencing of the transcriptome. Gene set enrichment analysis showed a coordinated down-regulation of genes involved in bone resorption, osteoclast differentiation and signaling, and apoptosis during hibernation. These findings are consistent with previous histological findings and likely contribute to the preservation of bone during the immobility of hibernation. In contrast, no significant enrichment indicating directional changes in gene expression was detected in the gene sets of bone formation and osteoblast signaling in hibernating bears. Additionally, we revealed significant and coordinated transcriptional induction of gene sets involved in aerobic energy production including fatty acid beta oxidation, tricarboxylic acid cycle, oxidative phosphorylation, and mitochondrial metabolism. Mitochondrial oxidation was likely up-regulated by transcriptionally induced AMPK/PGC1α pathway, an upstream stimulator of mitochondrial function.
Collapse
|
7
|
Donahue SW, Wojda SJ, McGee-Lawrence ME, Auger J, Black HL. Osteoporosis prevention in an extraordinary hibernating bear. Bone 2021; 145:115845. [PMID: 33450432 DOI: 10.1016/j.bone.2021.115845] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 01/06/2021] [Accepted: 01/07/2021] [Indexed: 11/20/2022]
Abstract
Disuse osteoporosis results from physical inactivity. Reduced mechanical loading of bone stimulates bone resorption leading to bone loss, decreased mechanical properties, and increased fracture risk. Compensatory mechanisms evolved in hibernators to preserve skeletal muscle and bone during the prolonged physical inactivity that occurs during annual hibernation. This paper reports the preservation of bone properties in an exceptionally old black bear that was physically inactive for about 6 months annually for 31 years. The biological mechanisms that preserve bone during prolonged disuse during hibernation are also reviewed.
Collapse
Affiliation(s)
- Seth W Donahue
- Department of Biomedical Engineering, University of Massachusetts, Amherst, United States of America.
| | - Samantha J Wojda
- Department of Biomedical Engineering, University of Massachusetts, Amherst, United States of America
| | - Meghan E McGee-Lawrence
- Department of Cellular Biology and Anatomy, Department of Orthopaedic Surgery, Medical College of Georgia, Augusta University, United States of America
| | - Janene Auger
- Monte L. Bean Life Science Museum, Brigham Young University, United States of America
| | - Hal L Black
- Department of Plant and Wildlife Sciences, Brigham Young University, United States of America
| |
Collapse
|
8
|
Teguh DA, Nustad JL, Craven AE, Brooks DJ, Arlt H, Hu D, Baron R, Lanske B, Bouxsein ML. Abaloparatide treatment increases bone formation, bone density and bone strength without increasing bone resorption in a rat model of hindlimb unloading. Bone 2021; 144:115801. [PMID: 33338664 DOI: 10.1016/j.bone.2020.115801] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 11/19/2020] [Accepted: 12/07/2020] [Indexed: 10/22/2022]
Abstract
Disuse osteoporosis can result from prolonged bed rest, paralysis, casts, braces, fractures and other conditions. Abaloparatide (ABL) is a PTHrP analog that increases bone density and strength by stimulating osteogenesis with limited effects on bone resorption. We examined skeletal responses to abaloparatide in young adult male rats with normal weight-bearing and with hindlimb unloading via a pelvic harness. Rats were allocated to four groups (10-12 per group): normal weight-bearing plus vehicle treatment (CON-VEH), normal weight-bearing plus ABL treatment (CON-ABL), hindlimb-unloading plus vehicle (HLU-VEH), or hindlimb-unloading plus ABL (HLU-ABL). Rats received ABL (25 μg/kg/day, s.c.) or vehicle throughout the 28-day unloading period and were then sacrificed, at which time HLU-VEH rats exhibited reduced bone formation and significant deficits in tibial, femoral, and vertebral bone mass compared with CON-VEH. ABL treatment increased serum osteocalcin in CON and HLU animals while having no effect on the osteoclast marker TRACP-5b. Longitudinal peripheral quantitative computed tomography (pQCT) indicated that ABL increased trabecular and cortical bone mass in the tibia. ABL was also associated with improved trabecular and cortical bone mass and architectural parameters at the femur, tibia, and vertebrae by μCT. Tibial histomorphometry indicated increased trabecular and endocortical bone formation with HLU-ABL versus HLU-VEH and with CON-ABL versus CON-VEH, and ABL was also associated with lower trabecular and endocortical osteoclast surfaces. Vertebral finite element analysis indicated higher ultimate load and stiffness for CON-ABL versus CON-VEH and for HLU-ABL versus HLU-VEH. In summary, ABL was associated with improved trabecular and cortical bone density and architecture in normal weight-bearing and hindlimb-unloaded rats, with higher bone formation and no difference in bone resorption. ABL was also associated with improved bone biomechanical parameters. These results provide rationale for investigating the ability of abaloparatide to prevent or treat disuse osteoporosis in humans.
Collapse
Affiliation(s)
- Dian A Teguh
- Center for Advanced Orthopaedic Studies, Department of Orthopaedic Surgery, Beth Israel Deaconess Medical Center, Boston, MA, USA; Department of Orthopaedic Surgery, Harvard Medical School, Boston, MA, USA
| | - Jordan L Nustad
- Center for Advanced Orthopaedic Studies, Department of Orthopaedic Surgery, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Amanda E Craven
- Center for Advanced Orthopaedic Studies, Department of Orthopaedic Surgery, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Daniel J Brooks
- Center for Advanced Orthopaedic Studies, Department of Orthopaedic Surgery, Beth Israel Deaconess Medical Center, Boston, MA, USA; Endocrine Unit, Massachusetts General Hospital, Boston, MA, USA
| | | | - Dorothy Hu
- Division of Bone and Mineral Research, Dept. of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine, Boston, MA, USA
| | - Roland Baron
- Division of Bone and Mineral Research, Dept. of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine, Boston, MA, USA; Endocrine Unit, Massachusetts General Hospital, Boston, MA, USA
| | | | - Mary L Bouxsein
- Center for Advanced Orthopaedic Studies, Department of Orthopaedic Surgery, Beth Israel Deaconess Medical Center, Boston, MA, USA; Department of Orthopaedic Surgery, Harvard Medical School, Boston, MA, USA; Endocrine Unit, Massachusetts General Hospital, Boston, MA, USA.
| |
Collapse
|
9
|
Abdala R, Levi L, Longobardi V, Zanchetta MB. Severe bone microarchitecture deterioration in a family with hereditary neuropathy: evidence of the key role of the mechanostat. Osteoporos Int 2020; 31:2477-2480. [PMID: 33047192 DOI: 10.1007/s00198-020-05674-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 10/06/2020] [Indexed: 11/25/2022]
Abstract
In this report, we present three cases of individuals from the same family with a diagnosis of CMT with severe tibia bone microarchitecture deterioration assessed by HR-pQCT. Charcot-Marie-Tooth disease (CMT) or hereditary neuropathy involves both motor and sensory nerves. Falls are often the first manifestation in these patients and represent an important risk factor for fracture. The reduction of mechanical input on bone inhibits bone formation by osteoblasts and accelerates bone resorption by osteoclasts, leading to disuse osteoporosis. We report three cases of individuals from the same family with a diagnosis of CMT with severe tibia bone microarchitecture deterioration assessed by high-resolution peripheral quantitative computed tomography (HR-pQCT). This affectation was exclusive to the tibia; the radius remained undamaged, showing the consequences of the lack of mobility and mechanical stimulation. Physical activity and rehabilitation, in addition to adequate calcium and vitamin D supplementation, may play an essential role in the management of this disease.
Collapse
Affiliation(s)
- R Abdala
- IDIM, Libertad 836, 1st Floor, Zip code 1012, Buenos Aires, Argentina.
- Cátedra de Osteología y Metabolismo Mineral, Universidad del Salvador, Buenos Aires, Argentina.
| | - L Levi
- IDIM, Libertad 836, 1st Floor, Zip code 1012, Buenos Aires, Argentina
| | - V Longobardi
- IDIM, Libertad 836, 1st Floor, Zip code 1012, Buenos Aires, Argentina
- Cátedra de Osteología y Metabolismo Mineral, Universidad del Salvador, Buenos Aires, Argentina
| | - M B Zanchetta
- IDIM, Libertad 836, 1st Floor, Zip code 1012, Buenos Aires, Argentina
- Cátedra de Osteología y Metabolismo Mineral, Universidad del Salvador, Buenos Aires, Argentina
| |
Collapse
|
10
|
Cirnigliaro CM, La Fountaine MF, Parrott JS, Kirshblum SC, McKenna C, Sauer SJ, Shapses SA, Hao L, McClure IA, Hobson JC, Spungen AM, Bauman WA. Administration of Denosumab Preserves Bone Mineral Density at the Knee in Persons With Subacute Spinal Cord Injury: Findings From a Randomized Clinical Trial. JBMR Plus 2020; 4:e10375. [PMID: 33134767 PMCID: PMC7587457 DOI: 10.1002/jbm4.10375] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 05/01/2020] [Accepted: 05/20/2020] [Indexed: 12/21/2022] Open
Abstract
Persons with neurologically motor-complete spinal cord injury (SCI) have a marked loss of bone mineral density (BMD) of the long bones of the lower extremities, predisposing them to fragility fractures, especially at the knee. Denosumab, a commercially available human monoclonal IgG antibody to receptor activator of nuclear factor-κB ligand (RANKL), may provide an immunopharmacological solution to the rapid progressive deterioration of sublesional bone after SCI. Twenty-six SCI participants with subacute motor-complete SCI were randomized to receive either denosumab (60 mg) or placebo at baseline (BL), 6, and 12 months. Areal bone mineral density (aBMD) by dual energy x-ray absorptiometry (DXA) at 18 months at the distal femur was the primary outcome and aBMD of the proximal tibia and hip were the secondary outcomes analyzed in 18 of the 26 participants (denosumab, n = 10 and placebo, n = 8). The metrics of peripheral QCT (pQCT) were the exploratory outcomes analyzed in a subsample of the cohort (denosumab, n = 7 and placebo n = 7). The mean aBMD (±95% CI) for the denosumab versus the placebo groups demonstrated a significant group × time interactions for the following regions of interest at BL and 18 months: distal femoral metaphysis = mean aBMD 1.187; 95% CI, 1.074 to 1.300 and mean aBMD 1.202; 95% CI, 1.074 to 1.329 versus mean aBMD 1.162; 95% CI, 0.962 to 1.362 and mean aBMD 0.961; 95% CI, 0.763 to 1.159, respectively (p < 0.001); distal femoral epiphysis = mean aBMD 1.557; 95% CI, 1.437 to 1.675 and mean aBMD 1.570; 95% CI, 1.440 to 1.700 versus mean aBMD 1.565; 95% CI, 1.434 to 1.696 and mean aBMD 1.103; 95% CI, 0.898 to 1.309, respectively (p = 0.002); and proximal tibial epiphysis = mean aBMD 1.071; 95% CI, 0.957 to 1.186 and mean aBMD 1.050; 95% CI, 0.932 to 1.168 versus mean aBMD 0.994; 95% CI, 0.879 to 1.109 and mean aBMD 0.760; 95% CI, 0.601 to 0.919, respectively (p < 0.001). Analysis of pQCT imaging revealed a continued trend toward significantly greater loss in total volumetric BMD (vBMD) and trabecular vBMD at the 4% distal tibia region, with a significant percent loss for total bone mineral content. Thus, at 18 months after acute SCI, our findings show that denosumab maintained aBMD at the knee region, the site of greatest clinical relevance in the SCI population. © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research.
Collapse
Affiliation(s)
- Christopher M Cirnigliaro
- Department of Veterans Affairs Rehabilitation Research & Development Service National Center for the Medical Consequences of Spinal Cord Injury James J. Peters Veterans Affairs Medical Center Bronx NY USA
| | - Michael F La Fountaine
- Department of Veterans Affairs Rehabilitation Research & Development Service National Center for the Medical Consequences of Spinal Cord Injury James J. Peters Veterans Affairs Medical Center Bronx NY USA.,Department of Physical Therapy, School of Health and Medical Sciences Seton Hall University South Orange NJ USA.,Departments of Medical Sciences and Neurology Hackensack Meridian School of Medicine at Seton Hall University Nutley NJ USA
| | - J Scott Parrott
- Department of Interdisciplinary Studies School of Health Professions, Rutgers Biomedical and Health Sciences Newark NJ USA
| | - Steven C Kirshblum
- Kessler Institute for Rehabilitation West Orange NJ USA.,Kessler Foundation West Orange NJ USA.,Department of Physical Medicine and Rehabilitation Rutgers New Jersey Medical School Newark NJ USA
| | - Cristin McKenna
- Kessler Institute for Rehabilitation West Orange NJ USA.,Kessler Foundation West Orange NJ USA
| | - Susan J Sauer
- Kessler Institute for Rehabilitation West Orange NJ USA
| | - Sue A Shapses
- Department of Nutritional Sciences, School of Environmental and Biological Sciences Rutgers University New Brunswick NJ USA
| | - Lihong Hao
- Department of Nutritional Sciences, School of Environmental and Biological Sciences Rutgers University New Brunswick NJ USA
| | - Isa A McClure
- Kessler Institute for Rehabilitation West Orange NJ USA
| | - Joshua C Hobson
- Department of Kinesiology and Applied Physiology University of Delaware Newark DE USA
| | - Ann M Spungen
- Department of Veterans Affairs Rehabilitation Research & Development Service National Center for the Medical Consequences of Spinal Cord Injury James J. Peters Veterans Affairs Medical Center Bronx NY USA.,Departments of Medicine and Rehabilitation and Human Performance Icahn School of Medicine at Mount Sinai New York NY USA
| | - William A Bauman
- Department of Veterans Affairs Rehabilitation Research & Development Service National Center for the Medical Consequences of Spinal Cord Injury James J. Peters Veterans Affairs Medical Center Bronx NY USA.,Departments of Medicine and Rehabilitation and Human Performance Icahn School of Medicine at Mount Sinai New York NY USA
| |
Collapse
|
11
|
Arfat Y, Rani A, Jingping W, Hocart CH. Calcium homeostasis during hibernation and in mechanical environments disrupting calcium homeostasis. J Comp Physiol B 2020; 190:1-16. [DOI: 10.1007/s00360-019-01255-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 11/21/2019] [Accepted: 12/16/2019] [Indexed: 12/22/2022]
|
12
|
Grover K, Hu M, Lin L, Muir J, Qin YX. Functional disuse initiates medullary endosteal micro-architectural impairment in cortical bone characterized by nanoindentation. J Bone Miner Metab 2019; 37:1048-1057. [PMID: 31292723 DOI: 10.1007/s00774-019-01011-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 05/16/2019] [Indexed: 01/22/2023]
Abstract
In this study, we evaluated the effect of functional disuse-induced bone remodeling on its mechanical properties, individually at periosteum and medullary endosteum regions of the cortical bone. Left middle tibiae were obtained from 5-month-old female Sprague-Dawley rats for the baseline control as well as hindlimb suspended (disuse) groups. Micro-nano-mechanical elastic moduli (at lateral region) was evaluated along axial (Z), circumferential (C) and radial (R) orientations using nanoindentation. Results indicated an anisotropic microstructure with axial orientation having the highest and radial orientation with the lowest moduli at periosteum and medullary endosteum for both baseline control as well as disuse groups. Between the groups: at periosteum, an insignificant difference was evaluated for each of the orientations (p > 0.05) and at endosteum, a significant decrease of elastic moduli in the radial (p < 0.0001), circumferential (p < 0.001) and statistically insignificant difference in axial (p > 0.05) orientation. For the moduli ratios between groups: at periosteum, only significant difference in the Z/R (p < 0.05) anisotropy ratio, whereas at endosteum, a statistically significant difference in Z/C (p < 0.001), and Z/R (p < 0.001), as well as C/R (p < 0.05) anisotropy ratios, was evaluated. The results suggested initial bone remodeling impaired bone micro-architecture predominantly at the medullary endosteum with possible alterations in the geometric orientations of collagen and mineral phases inside the bone. The findings could be significant for studying the mechanotransduction pathways involved in maintaining the bone micro-architecture and possibly have high clinical significance for drug use against impairment from functional disuse.
Collapse
Affiliation(s)
- Kartikey Grover
- Department of Biomedical Engineering, SUNY Stony Brook University, 215 Bioengineering Building, Stony Brook, New York, 11794, USA
| | - Minyi Hu
- Department of Biomedical Engineering, SUNY Stony Brook University, 215 Bioengineering Building, Stony Brook, New York, 11794, USA
| | - Liangjun Lin
- Department of Biomedical Engineering, SUNY Stony Brook University, 215 Bioengineering Building, Stony Brook, New York, 11794, USA
| | - Jesse Muir
- Department of Biomedical Engineering, SUNY Stony Brook University, 215 Bioengineering Building, Stony Brook, New York, 11794, USA
| | - Yi-Xian Qin
- Department of Biomedical Engineering, SUNY Stony Brook University, 215 Bioengineering Building, Stony Brook, New York, 11794, USA.
| |
Collapse
|
13
|
Yang PF, Nie XT, Wang Z, Al-Qudsy LHH, Ren L, Xu HY, Rittweger J, Shang P. Disuse Impairs the Mechanical Competence of Bone by Regulating the Characterizations of Mineralized Collagen Fibrils in Cortical Bone. Front Physiol 2019; 10:775. [PMID: 31293444 PMCID: PMC6598106 DOI: 10.3389/fphys.2019.00775] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 06/03/2019] [Indexed: 12/15/2022] Open
Abstract
Bones are made of complex material comprising organic components and mineral hydroxyapatite, both of which formulate the unique hierarchical structure of bone and its mechanical properties. Bones are capable of optimizing their structure and mechanical properties according to the mechanical environment. Mineral loss is a well-known consequence of skeleton disuse. By contrast, the response of the non-mineral phase of bone, i.e., the collagen network, during disuse remain largely unknown. In this study, a tail-suspension mice model was used to induce bone loss. Atomic force microscopy-based imaging and indentation approaches were adopted to investigate the influence of disuse on the morphology and in situ mechanical behavior of the collagen fibrils, under both non-loaded and load-bearing conditions, in the cortical tibia of mice. The results indicate that disuse induced by hindlimb unloading did not alter the orientation and D-periodic spacing of the collagen fibril, but results in decreased collagen crosslinking which correlates with decreased elasticity and increased susceptibility to mechanical damage. More concretely, the collagen fibrils in the disused tibia were misaligned under mechanical loading. It therefore indicates that the disordered arrangement of the mineralized collagen fibrils is one of the characteristics of the weakened bone during elastic deformation. These findings reveals the unique adaptation regimes of the collagen fibrils in the cortical bone to disuse, as well as the deformation mechanisms of bone in the relevant pathological process at different scales.
Collapse
Affiliation(s)
- Peng-Fei Yang
- Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Institute of Special Environmental Biophysics, Northwestern Polytechnical University, Xi'an, China.,Research & Development Institute, Northwestern Polytechnical University, Shenzhen, China.,Yangtze River Delta Research Institute, Northwestern Polytechnical University, Taicang, China
| | - Xiao-Tong Nie
- Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Institute of Special Environmental Biophysics, Northwestern Polytechnical University, Xi'an, China
| | - Zhe Wang
- Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Institute of Special Environmental Biophysics, Northwestern Polytechnical University, Xi'an, China
| | - Luban Hamdy Hameed Al-Qudsy
- Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Institute of Special Environmental Biophysics, Northwestern Polytechnical University, Xi'an, China
| | - Li Ren
- Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Institute of Special Environmental Biophysics, Northwestern Polytechnical University, Xi'an, China.,Research & Development Institute, Northwestern Polytechnical University, Shenzhen, China
| | - Hui-Yun Xu
- Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Institute of Special Environmental Biophysics, Northwestern Polytechnical University, Xi'an, China.,Research & Development Institute, Northwestern Polytechnical University, Shenzhen, China
| | - Joern Rittweger
- Division of Muscle & Bone Metabolism, Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany.,Department of Pediatrics and Adolescent Medicine, University of Cologne, Cologne, Germany
| | - Peng Shang
- Research & Development Institute, Northwestern Polytechnical University, Shenzhen, China.,Key Laboratory for Space Bioscience and Biotechnology, Institute of Special Environmental Biophysics, Northwestern Polytechnical University, Xi'an, China
| |
Collapse
|
14
|
Kim J, Jang SB, Kim SW, Oh JK, Kim TH. Clinical effect of early bisphosphonate treatment for pyogenic vertebral osteomyelitis with osteoporosis: An analysis by the Cox proportional hazard model. Spine J 2019; 19:418-429. [PMID: 30172897 DOI: 10.1016/j.spinee.2018.08.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 08/27/2018] [Accepted: 08/27/2018] [Indexed: 02/03/2023]
Abstract
BACKGROUND CONTEXT Patients with pyogenic vertebral osteomyelitis (PVO) are expected to have an increased risk of bone loss. Therefore, early bisphosphonate therapy would be clinically effective for PVO patients with osteoporosis. PURPOSE This study aimed to investigate the effect of bisphosphonate on clinical outcomes of PVO patients with osteoporosis. STUDY DESIGN/SETTING A retrospective comparative study. PATIENT SAMPLE PVO patients with osteoporosis. OUTCOME MEASURES Four events of interest for Cox proportional hazard model included surgical treatment, recurrence of infection, subsequent fracture of adjacent vertebral bodies, and death. METHODS PVO patients were divided into three groups: group A (initiation of bisphosphonate within 6 weeks after PVO diagnosis), group B (initiation of bisphosphonate between 6 weeks and 3 months after PVO diagnosis), and group C (no treatment for osteoporosis). Cox proportional hazard model was used for the four events of interest. RESULTS A total of 360 PVO patients with osteoporosis were investigated for the four events of interest. Group A had significantly lower hazard ratios for undergoing later (>6 weeks after diagnosis) surgery than group C (p = .014) despite similar occurrences of overall surgery. A significant difference was also observed in the occurrence of subsequent fractures at adjacent vertebral bodies (p = .001 for model 1 and p = .002 for model 2). Groups A and B had significantly lower hazard ratios for subsequent fracture than group C. No significant differences were observed in the hazard ratios of recurrence and death among the three groups. CONCLUSIONS Early bisphosphonate treatment in PVO patients with osteoporosis was associated with a significantly lower occurrence of subsequent vertebral fracture at adjacent vertebral bodies and lower occurrence of subsequent surgery.
Collapse
Affiliation(s)
- Jihye Kim
- Division of Infection, Department of Pediatrics, Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, South Korea
| | - Seung Bo Jang
- Spine Center, Department of Orthopedics, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, 896, Pyeongchon-Dong, Anyang, Gyeonggi-Do 431-070, South Korea
| | - Seok Woo Kim
- Spine Center, Department of Orthopedics, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, 896, Pyeongchon-Dong, Anyang, Gyeonggi-Do 431-070, South Korea
| | - Jae-Keun Oh
- Spine Center, Department of Orthopedics, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, 896, Pyeongchon-Dong, Anyang, Gyeonggi-Do 431-070, South Korea
| | - Tae-Hwan Kim
- Spine Center, Department of Orthopedics, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, 896, Pyeongchon-Dong, Anyang, Gyeonggi-Do 431-070, South Korea.
| |
Collapse
|
15
|
Kim J, Kim SW, Lee SY, Kim TH, Jung JH. Bone mineral density in osteoporotic patients with pyogenic vertebral osteomyelitis: effect of early versus late treatment for osteoporosis. Osteoporos Int 2018; 29:2761-2770. [PMID: 30225674 DOI: 10.1007/s00198-018-4695-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Accepted: 09/03/2018] [Indexed: 12/19/2022]
Abstract
UNLABELLED Patients with pyogenic vertebral osteomyelitis (PVO) are at greater risk of bone loss. However, treatment guidelines for bone loss have been lacking. Early bisphosphonate treatment within 6 weeks after PVO diagnosis was significantly associated with superior outcome in femoral BMD at 2-year follow-up, compared to that with late treatment. INTRODUCTION Due to absence of concern and proper guidelines, management of bone loss or osteoporosis in PVO is often neglected or delayed. A retrospective cohort study was planned to investigate differences in bone mineral density (BMD) in PVO patients with osteoporosis according to the timing of osteoporosis treatment. METHODS The PVO cohort consisted of 192 patients with osteoporosis who visited our institution between January 2003 and March 2015 and received bisphosphonate treatment for osteoporosis. According to the interval between PVO diagnosis and initiation of bisphosphonate, the patients were divided into three groups: group A (within 6 weeks after PVO diagnosis), group B (between 6 weeks and 3 months after diagnosis), and group C (more than 3 months after PVO diagnosis). RESULTS The percent increase in total femoral BMD in group A was significantly larger than that in group B at 2-year follow-up (p = 0.036). Similarly, the percent increase in trochanteric (p = 0.008) and total femoral (p = 0009) BMD in group A was significantly larger than that in group C at 2-year follow-up. Even after multivariate adjustment, total femoral BMD changes were significantly associated with the treatment group. Group B (odds ratio = 2.824, p = 0.013) and group C (odds ratio = 3.591, p = 0.001) were more significantly associated with total femoral BMD decreases at 2-year follow-up compared with group A. CONCLUSIONS Early bisphosphonate treatment within 6 weeks after PVO diagnosis (group A) was significantly associated with superior outcome in femoral BMD at 2-year follow-up, compared to that with late treatment (groups B and C).
Collapse
Affiliation(s)
- J Kim
- Division of Infection, Department of Pediatrics, Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, South Korea
| | - S W Kim
- Spine Center, Department of Orthopedics, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang, South Korea
| | - S Y Lee
- Spine Center, Department of Orthopedics, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang, South Korea
| | - T-H Kim
- Spine Center, Department of Orthopedics, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang, South Korea.
| | - J-H Jung
- Spine Center, Department of Orthopedics, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang, South Korea
| |
Collapse
|
16
|
Bioinspired bone therapies using naringin: applications and advances. Drug Discov Today 2018; 23:1293-1304. [PMID: 29747006 DOI: 10.1016/j.drudis.2018.05.012] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 03/31/2018] [Accepted: 05/02/2018] [Indexed: 12/26/2022]
Abstract
The use of natural compounds for treating chronic bone diseases holds remarkable potential. Among these therapeutics, naringin, a flavanone glycoside, represents one of the most promising candidates owing to its multifaceted effect on bone tissues. This review provides an up-to-date overview on naringin applications in the treatment of bone disorders, such as osteoporosis and osteoarthritis, and further highlights its potential for stem cell pro-osteogenic differentiation therapies. A critical perspective on naringin clinical translation is also provided. The topic is discussed in light of recently developed biomaterial-based approaches that potentiate its bioavailability and bioactivity. Overall, the reported pro-osteogenic, antiresorptive and antiadipogenic properties establish this flavanone as an exciting candidate for application in bone tissue engineering and regenerative medicine.
Collapse
|
17
|
Pineda N, Owen M, Tucker C, Wojda S, Kitchen S, Black H, Donahue S. Hibernating Little Pocket Mice Show Few Seasonal Changes in Bone Properties. Anat Rec (Hoboken) 2017; 300:2175-2183. [PMID: 28806499 DOI: 10.1002/ar.23676] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 05/11/2017] [Accepted: 05/31/2017] [Indexed: 11/09/2022]
Abstract
Periods of disuse or physical inactivity increases bone porosity and decreases bone mineral density, resulting in a loss of bone mechanical competence in many animals. Although large hibernators like bears and marmots prevent bone loss during hibernation, despite long periods of physical inactivity, some small hibernators do lose bone during hibernation. Little pocket mice (Perognathus longimembris) remain underground during winter hibernation and undergo bouts of torpor and interbout arousals, but the torpor bout duration is shorter than other rodent hibernators. Additionally, little pocket mice may enter torpor during summer estivation. In this study, cortical and trabecular bone architectural, mineral, and mechanical properties were analyzed for femurs from little pocket mice captured during 8 different months (March to October) to determine seasonal effects on bone. There were no differences in any bone properties between the pre-hibernation month of October and the post-hibernation month of March, suggesting winter hibernation did not adversely affect bone properties. However, cortical area was higher in March than April, May, and June. Bone mechanical and osteocyte lacunar properties were not different between any months. Trabecular bone in the distal femoral epiphysis showed no changes between months. The distal femoral metaphyseal region showed higher trabecular spacing and lower trabecular number in May than August, otherwise, there were no differences in trabecular parameters. The few monthly differences in bone properties may be due to physical inactivity from periodic summer estivation or from the timing of birth and growth in spring and summer months. Anat Rec, 300:2175-2183, 2017. © 2017 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Noellyn Pineda
- School of Biomedical Engineering, Colorado State University, Fort Collins, Colorado.,Department of Mechanical Engineering, Colorado State University, Fort Collins, Colorado
| | - Marjorie Owen
- Department of Mechanical Engineering, Colorado State University, Fort Collins, Colorado
| | - Claire Tucker
- Department of Mechanical Engineering, Colorado State University, Fort Collins, Colorado
| | - Samantha Wojda
- Department of Mechanical Engineering, Colorado State University, Fort Collins, Colorado
| | - Stanley Kitchen
- US Forest Service, Rocky Mountain Research Station, Provo, Utah
| | - Hal Black
- Department of Plant and Wildlife Sciences, Brigham Young University, Provo, Utah
| | - Seth Donahue
- School of Biomedical Engineering, Colorado State University, Fort Collins, Colorado.,Department of Mechanical Engineering, Colorado State University, Fort Collins, Colorado
| |
Collapse
|
18
|
Li B, Liu J, Zhao J, Ma JX, Jia HB, Zhang Y, Xing GS, Ma XL. LncRNA-H19 Modulates Wnt/β-catenin Signaling by Targeting Dkk4 in Hindlimb Unloaded Rat. Orthop Surg 2017; 9:319-327. [PMID: 28447380 DOI: 10.1111/os.12321] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 02/18/2017] [Indexed: 02/06/2023] Open
Abstract
OBJECTIVE To investigate the biological functions of long noncoding RNA-H19 (H19) in the pathogenesis of disuse osteoporosis (DOP). METHODS Fifty-four male Sprague Dawley (SD) rats were randomly divided into three groups: baseline control (BC, 6), age-matched control (AC, 24), and hindlimb unloading (HLU, 24). The rats in the BC group were sacrificed at the beginning of the experiment, while the AC and HLU rats were sacrificed at different times (7, 14, 21 and 28 days after HLU). The DOP model was verified by micro-CT scan, and quantitative real-time polymerase chain reaction (qRT-PCR) was used to quantify the expression of osteogenic genes (OPG, RunX2 and OPG). Gene sequencing and bioinformatic analysis were performed to find H19 target genes and the associated signaling pathway, which were first verified on tissue samples. Further verification was performed by knocking down the H19 and related gene in rat osteoblast cell line (UMR106 cell). Then, the changes of associated signaling pathway and osteogenic function were examined to confirm the prediction of the bioinformatic analysis. RESULTS Micro-CT scans and quantitative real-time polymerase chain reaction (qRT-PCR) tests showed progressively deteriorated trabecular bone and decreased level of osteogenic genes in the metaphysis of distal femur during HLU, indicating the successful establishment of a DOP model. According to RNA sequencing, 1351 mRNA and 464 lncRNA were abnormally expressed in response to mechanical unloading, in which the H19 decreased 2.86 fold in HLU rats. There were 1426 mRNA predicted to be the target genes of H19, and KEGG pathway analysis suggested that Wnt signaling pathway (Wnt signaling) was the top pathway responsible for these target genes. In the Wnt-associated genes targeted by H19, 11 were differentially expressed between HLU and AC rats, among which Dkk4 increased 2.44 fold in HLU rats when compared to normal controls. These results of sequencing and bioinformatic analysis were confirmed by the low expression of H19, overexpression of Dkk4 and inhibited Wnt signaling observed in DOP rats. Subsequent in vitro cell assay further demonstrated that knockdown of H19 led to upregulation of Dkk4, and inhibition of Wnt signaling and osteogenic function in UMR106 cell. These effects can be greatly reversed after application of knocking down Dkk4. CONCLUSION Our findings demonstrated that low expression of H19, induced by mechanical unloading, leads to development of DOP through inhibition of Wnt signaling by promoting Dkk4 expression.
Collapse
Affiliation(s)
- Bing Li
- Department of Joint, Tianjin Hospital, Tianjin, China
| | - Jun Liu
- Department of Joint, Tianjin Hospital, Tianjin, China
| | - Jie Zhao
- Department of Biomechanics, Orthopaedic Research Institute, Tianjin Hospital, Tianjin, China
| | - Jian-Xiong Ma
- Department of Biomechanics, Orthopaedic Research Institute, Tianjin Hospital, Tianjin, China
| | - Hao-Bo Jia
- Department of Biomechanics, Orthopaedic Research Institute, Tianjin Hospital, Tianjin, China
| | - Yang Zhang
- Department of Biomechanics, Orthopaedic Research Institute, Tianjin Hospital, Tianjin, China
| | - Guo-Sheng Xing
- Department of Biomechanics, Orthopaedic Research Institute, Tianjin Hospital, Tianjin, China
| | - Xin-Long Ma
- Department of Biomechanics, Orthopaedic Research Institute, Tianjin Hospital, Tianjin, China
| |
Collapse
|
19
|
Evidence of the Role of R-Spondin 1 and Its Receptor Lgr4 in the Transmission of Mechanical Stimuli to Biological Signals for Bone Formation. Int J Mol Sci 2017; 18:ijms18030564. [PMID: 28272338 PMCID: PMC5372580 DOI: 10.3390/ijms18030564] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2017] [Revised: 02/23/2017] [Accepted: 02/28/2017] [Indexed: 01/28/2023] Open
Abstract
The bone can adjust its mass and architecture to mechanical stimuli via a series of molecular cascades, which have been not yet fully elucidated. Emerging evidence indicated that R-spondins (Rspos), a family of secreted agonists of the Wnt/β-catenin signaling pathway, had important roles in osteoblastic differentiation and bone formation. However, the role of Rspo proteins in mechanical loading-influenced bone metabolism has never been investigated. In this study, we found that Rspo1 was a mechanosensitive protein for bone formation. Continuous cyclic mechanical stretch (CMS) upregulated the expression of Rspo1 in mouse bone marrow mesenchymal stem cells (BMSCs), while the expression of Rspo1 in BMSCs in vivo was downregulated in the bones of a mechanical unloading mouse model (tail suspension (TS)). On the other hand, Rspo1 could promote osteogenesis of BMSCs under CMS through activating the Wnt/β-catenin signaling pathway and could rescue the bone loss induced by mechanical unloading in the TS mice. Specifically, our results suggested that Rspo1 and its receptor of leucine-rich repeat containing G-protein-coupled receptor 4 (Lgr4) should be a novel molecular signal in the transmission of mechanical stimuli to biological signal in the bone, and this signal should be in the upstream of Wnt/β-catenin signaling for bone formation. Rspo1/Lgr4 could be a new potential target for the prevention and treatment of disuse osteoporosis in the future.
Collapse
|
20
|
Naruse K, Uchida K, Suto M, Miyagawa K, Kawata A, Urabe K, Takaso M, Itoman M, Mikuni-Takagaki Y. Alendronate does not prevent long bone fragility in an inactive rat model. J Bone Miner Metab 2016; 34:615-626. [PMID: 26475371 DOI: 10.1007/s00774-015-0714-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2014] [Accepted: 08/25/2015] [Indexed: 02/07/2023]
Abstract
The lack of estrogen and inactivity are both important in the pathogenesis of osteoporosis in elderly women, and there have been no appropriate rodent studies to examine the effects of common bisphosphonates on these two components separately. We compared the efficacy of alendronate (ALN) on the long bones of aged female rats, which were sedentary, estrogen deficient, or both. The rats were either forced to remain in a sitting position or allowed to walk in standard cages with or without ALN administration. The 8-week experimental period began 5 weeks after ovariectomy or sham surgery. Parameters of the hindlimb bones were determined by a three-point bending test, peripheral quantitative computed tomography, microfocus computed tomography, confocal laser Raman microspectroscopy, and dynamic histomorphometry. Regardless of ovariectomy, ALN was ineffective against the deterioration of breaking stress caused by sitting even though the trabecular bone mineral density was significantly higher in the sitting-ALN groups. Toughness was significantly deficient in the ovariectomy sitting-ALN group. This was in agreement with the bone geometry with a greater marrow space. Sitting also increased the mineral-to-matrix ratio and the carbonate-to-phosphate ratio, both indicative of aged bone. A greater loss of proteinaceous amide intensity compared with mineral intensity resulted in an increased mineral-to-matrix ratio in the presence of ALN. Sitting resulted in deficits in the quality and the geometry of cortical bone, resulting in fragility. The use of bisphosphonates, such as ALN, may provide a therapy best suited for osteoporotic individuals whose daily activity is not limited.
Collapse
Affiliation(s)
- K Naruse
- Department of Orthopedic Surgery, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara, 252-0374, Japan
| | - K Uchida
- Department of Orthopedic Surgery, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara, 252-0374, Japan
| | - M Suto
- Department of Orthopedic Surgery, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara, 252-0374, Japan
- Suto Orthopedic Clinic, Katagama, Japan
| | - K Miyagawa
- First Department of Oral and Maxillofacial Surgery, Osaka University Graduate School of Dentistry, Osaka, Japan
| | - A Kawata
- Department of Oral Sciences, Division of Molecular and Cellular Biology of Mineralized Tissues, Kanagawa Dental University Graduate School of Dentistry, 82 Inaokacho, Yokosuka, Kanagawa, 238-8580, Japan
| | - K Urabe
- Department of Orthopedic Surgery, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara, 252-0374, Japan
| | - M Takaso
- Department of Orthopedic Surgery, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara, 252-0374, Japan
| | - M Itoman
- Department of Orthopedic Surgery, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara, 252-0374, Japan
| | - Y Mikuni-Takagaki
- Department of Oral Sciences, Division of Molecular and Cellular Biology of Mineralized Tissues, Kanagawa Dental University Graduate School of Dentistry, 82 Inaokacho, Yokosuka, Kanagawa, 238-8580, Japan.
| |
Collapse
|
21
|
Bogren LK, Johnston EL, Barati Z, Martin PA, Wojda SJ, Van Tets IG, LeBlanc AD, Donahue SW, Drew KL. The effects of hibernation and forced disuse (neurectomy) on bone properties in arctic ground squirrels. Physiol Rep 2016; 4:4/10/e12771. [PMID: 27225624 PMCID: PMC4886160 DOI: 10.14814/phy2.12771] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 03/22/2016] [Indexed: 12/11/2022] Open
Abstract
Bone loss is a well‐known medical consequence of disuse such as in long‐term space flight. Immobilization in many animals mimics the effects of space flight on bone mineral density. Decreases in metabolism are also thought to contribute to a loss of skeletal mass. Hibernating mammals provide a natural model of disuse and metabolic suppression. Hibernating ground squirrels have been shown to maintain bone strength despite long periods of disuse and decreased metabolism during torpor. This study examined if the lack of bone loss during torpor was a result of the decrease in metabolic rate during torpor or an evolutionary change in these animals affording protection against disuse. We delineated changes in bone density during natural disuse (torpor) and forced disuse (sciatic neurectomy) in the hind limbs of the arctic ground squirrel (AGS) over an entire year. We hypothesized that the animals would be resistant to bone loss due to immobilization and disuse during the winter hibernation season when metabolism is depressed but not the summer active season. This hypothesis was not supported. The animals maintained bone density (dual‐energy X‐ray absorptiometry) and most bone structural and mechanical properties in both seasons. This was observed in both natural and forced disuse, regardless of the known metabolic rate increase during the summer. However, trabecular bone volume fraction (microcomputed tomography) in the distal femur was lower in neurectomized AGS at the study endpoint. These results demonstrate a need to better understand the relationship between skeletal load (use) and bone density that may lead to therapeutics or strategies to maintain bone density in disuse conditions.
Collapse
Affiliation(s)
- Lori K Bogren
- Chemistry and Biochemistry Department, Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska
| | - Erin L Johnston
- Chemistry and Biochemistry Department, Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska
| | - Zeinab Barati
- Chemistry and Biochemistry Department, Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska
| | - Paula A Martin
- Chemistry and Biochemistry Department, Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska
| | - Samantha J Wojda
- Mechanical Engineering Department, Colorado State University, Fort Collins, Colorado
| | - Ian G Van Tets
- Department of Biological Sciences, University of Alaska Anchorage, Anchorage, Alaska
| | | | - Seth W Donahue
- Mechanical Engineering Department, Colorado State University, Fort Collins, Colorado
| | - Kelly L Drew
- Chemistry and Biochemistry Department, Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska
| |
Collapse
|
22
|
Ferreño D, Sainz-Aja JA, Carrascal IA, Diego S, Ruiz E, Casado JA, Riancho JA, Sañudo C, Gutiérrez-Solana F. Orientation of whole bone samples of small rodents matters during bending tests. J Mech Behav Biomed Mater 2016; 65:200-212. [PMID: 27591507 DOI: 10.1016/j.jmbbm.2016.08.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Revised: 07/27/2016] [Accepted: 08/21/2016] [Indexed: 11/28/2022]
Abstract
The influence of the orientation of rat bones on their mechanical response is analyzed in this research. 28 femora obtained from 14 Sprague-Dawley rats were subjected to three-point bending tests, comparing the anteroposterior and posteroanterior orientations. The results show that the whole-bone loading capacity of the femora tested in the posteroanterior orientation clearly exceeds that of the anteroposterior oriented bones. Likewise, the intrinsic (tissue-level) loading capacity of the bones tested in the posteroanterior orientation is manifestly higher than that of the bones tested in the opposite direction. The analysis carried out shows that applying beam theory for symmetric cross-sections leads to underestimating the stress state in the cross-section. In this sense, it is generally recommendable to use the non-symmetric beam theory in order to obtain the normal stresses during bending tests. The geometric, intrinsic and global changes resulting from the orientation of the bones was assessed, finding out that it is the variation in the intrinsic properties which explains the change measured in the whole-bone properties. The experimental scope was increased, including 8 additional femora on which a series of Vickers tests were carried out in the anterior and posterior regions of the cross-section. In all cases the hardness obtained in the anterior region is larger than in the posterior region. This result confirms that the mechanical properties of the bone tissue depend on its position in the cross-section and provides a reliable explanation to understand the response of the bones when subjected to bending tests. These results stress the importance of reporting the orientation of the bones in any scientific paper because, otherwise, it would be impossible to properly assess its impact and relevance.
Collapse
Affiliation(s)
- Diego Ferreño
- LADICIM (Laboratory of Materials Science and Engineering), University of Cantabria, E.T.S. de Ingenieros de Caminos, Canales y Puertos, Av/Los Castros 44, 39005 Santander, Spain.
| | - José A Sainz-Aja
- LADICIM (Laboratory of Materials Science and Engineering), University of Cantabria, E.T.S. de Ingenieros de Caminos, Canales y Puertos, Av/Los Castros 44, 39005 Santander, Spain
| | - Isidro A Carrascal
- LADICIM (Laboratory of Materials Science and Engineering), University of Cantabria, E.T.S. de Ingenieros de Caminos, Canales y Puertos, Av/Los Castros 44, 39005 Santander, Spain
| | - Soraya Diego
- LADICIM (Laboratory of Materials Science and Engineering), University of Cantabria, E.T.S. de Ingenieros de Caminos, Canales y Puertos, Av/Los Castros 44, 39005 Santander, Spain
| | - Estela Ruiz
- LADICIM (Laboratory of Materials Science and Engineering), University of Cantabria, E.T.S. de Ingenieros de Caminos, Canales y Puertos, Av/Los Castros 44, 39005 Santander, Spain
| | - José A Casado
- LADICIM (Laboratory of Materials Science and Engineering), University of Cantabria, E.T.S. de Ingenieros de Caminos, Canales y Puertos, Av/Los Castros 44, 39005 Santander, Spain
| | - José A Riancho
- Department of Internal Medicine, Faculty of Medicine, Marqués de Valdecilla University Hospital, University of Cantabria, IDIVAL, Av/Valdecilla s/n, Santander 39008, Spain
| | - Carolina Sañudo
- Department of Internal Medicine, Faculty of Medicine, Marqués de Valdecilla University Hospital, University of Cantabria, IDIVAL, Av/Valdecilla s/n, Santander 39008, Spain
| | - Federico Gutiérrez-Solana
- LADICIM (Laboratory of Materials Science and Engineering), University of Cantabria, E.T.S. de Ingenieros de Caminos, Canales y Puertos, Av/Los Castros 44, 39005 Santander, Spain
| |
Collapse
|
23
|
Reilly BD, Franklin CE. Prevention of muscle wasting and osteoporosis: the value of examining novel animal models. J Exp Biol 2016; 219:2582-95. [DOI: 10.1242/jeb.128348] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
ABSTRACT
Bone mass and skeletal muscle mass are controlled by factors such as genetics, diet and nutrition, growth factors and mechanical stimuli. Whereas increased mechanical loading of the musculoskeletal system stimulates an increase in the mass and strength of skeletal muscle and bone, reduced mechanical loading and disuse rapidly promote a decrease in musculoskeletal mass, strength and ultimately performance (i.e. muscle atrophy and osteoporosis). In stark contrast to artificially immobilised laboratory mammals, animals that experience natural, prolonged bouts of disuse and reduced mechanical loading, such as hibernating mammals and aestivating frogs, consistently exhibit limited or no change in musculoskeletal performance. What factors modulate skeletal muscle and bone mass, and what physiological and molecular mechanisms protect against losses of muscle and bone during dormancy and following arousal? Understanding the events that occur in different organisms that undergo natural periods of prolonged disuse and suffer negligible musculoskeletal deterioration could not only reveal novel regulatory factors but also might lead to new therapeutic options. Here, we review recent work from a diverse array of species that has revealed novel information regarding physiological and molecular mechanisms that dormant animals may use to conserve musculoskeletal mass despite prolonged inactivity. By highlighting some of the differences and similarities in musculoskeletal biology between vertebrates that experience disparate modes of dormancy, it is hoped that this Review will stimulate new insights and ideas for future studies regarding the regulation of atrophy and osteoporosis in both natural and clinical models of muscle and bone disuse.
Collapse
Affiliation(s)
- Beau D. Reilly
- School of Biological Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Craig E. Franklin
- School of Biological Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| |
Collapse
|
24
|
Doherty AH, Roteliuk DM, Gookin SE, McGrew AK, Broccardo CJ, Condon KW, Prenni JE, Wojda SJ, Florant GL, Donahue SW. Exploring the Bone Proteome to Help Explain Altered Bone Remodeling and Preservation of Bone Architecture and Strength in Hibernating Marmots. Physiol Biochem Zool 2016; 89:364-76. [DOI: 10.1086/687413] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
25
|
Cabahug-Zuckerman P, Frikha-Benayed D, Majeska RJ, Tuthill A, Yakar S, Judex S, Schaffler MB. Osteocyte Apoptosis Caused by Hindlimb Unloading is Required to Trigger Osteocyte RANKL Production and Subsequent Resorption of Cortical and Trabecular Bone in Mice Femurs. J Bone Miner Res 2016; 31:1356-65. [PMID: 26852281 PMCID: PMC5488280 DOI: 10.1002/jbmr.2807] [Citation(s) in RCA: 121] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Revised: 02/02/2016] [Accepted: 02/04/2016] [Indexed: 12/20/2022]
Abstract
Osteocyte apoptosis is essential to activate bone remodeling in response to fatigue microdamage and estrogen withdrawal, such that apoptosis inhibition in vivo prevents the onset of osteoclastic resorption. Osteocyte apoptosis has also been spatially linked to bone resorption owing to disuse, but whether apoptosis plays a similar controlling role is unclear. We, therefore, 1) evaluated the spatial and temporal effects of disuse from hindlimb unloading (HLU) on osteocyte apoptosis, receptor activator of NF-κB ligand (RANKL) expression, bone resorption, and loss in mouse femora, and 2) tested whether osteocyte apoptosis was required to activate osteoclastic activity in cortical and trabecular bone by treating animals subjected to HLU with the pan-caspase apoptosis inhibitor, QVD (quinolyl-valyl-O-methylaspartyl-[-2,6-difluorophenoxy]-methylketone). Immunohistochemistry was used to identify apoptotic and RANKL-producing osteocytes in femoral diaphysis and distal trabecular bone, and µCT was used to determine the extent of trabecular bone loss owing to HLU. In both cortical and trabecular bone, 5 days of HLU increased osteocyte apoptosis significantly (3- and 4-fold, respectively, p < 0.05 versus Ctrl). At day 14, the apoptotic osteocyte number in femoral cortices declined to near control levels but remained elevated in trabeculae (3-fold versus Ctrl, p < 0.05). The number of osteocytes producing RANKL in both bone compartments was also significantly increased at day 5 of HLU (>1.5-fold versus Ctrl, p < 0.05) and further increased by day 14. Increases in osteocyte apoptosis and RANKL production preceded increases in bone resorption at both endocortical and trabecular surfaces. QVD completely inhibited not only the HLU-triggered increases in osteocyte apoptosis but also RANKL production and activation of bone resorption at both sites. Finally, µCT studies revealed that apoptosis inhibition completely prevented the trabecular bone loss caused by HLU. Together these data indicate that osteocyte apoptosis plays a central and controlling role in triggering osteocyte RANKL production and the activation of new resorption leading to bone loss in disuse. © 2016 American Society for Bone and Mineral Research.
Collapse
Affiliation(s)
| | - Dorra Frikha-Benayed
- Department of Biomedical Engineering, City College of New York, New York, NY, USA
| | - Robert J Majeska
- Department of Biomedical Engineering, City College of New York, New York, NY, USA
| | - Alyssa Tuthill
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA
| | - Shoshana Yakar
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, NY, USA
| | - Stefan Judex
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA
| | - Mitchell B Schaffler
- Department of Biomedical Engineering, City College of New York, New York, NY, USA
| |
Collapse
|
26
|
McGee-Lawrence M, Buckendahl P, Carpenter C, Henriksen K, Vaughan M, Donahue S. Suppressed bone remodeling in black bears conserves energy and bone mass during hibernation. ACTA ACUST UNITED AC 2016; 218:2067-74. [PMID: 26157160 DOI: 10.1242/jeb.120725] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Decreased physical activity in mammals increases bone turnover and uncouples bone formation from bone resorption, leading to hypercalcemia, hypercalcuria, bone loss and increased fracture risk. Black bears, however, are physically inactive for up to 6 months annually during hibernation without losing cortical or trabecular bone mass. Bears have been shown to preserve trabecular bone volume and architectural parameters and cortical bone strength, porosity and geometrical properties during hibernation. The mechanisms that prevent disuse osteoporosis in bears are unclear as previous studies using histological and serum markers of bone remodeling show conflicting results. However, previous studies used serum markers of bone remodeling that are known to accumulate with decreased renal function, which bears have during hibernation. Therefore, we measured serum bone remodeling markers (BSALP and TRACP) that do not accumulate with decreased renal function, in addition to the concentrations of serum calcium and hormones involved in regulating bone remodeling in hibernating and active bears. Bone resorption and formation markers were decreased during hibernation compared with when bears were physically active, and these findings were supported by histomorphometric analyses of bone biopsies. The serum concentration of cocaine and amphetamine regulated transcript (CART), a hormone known to reduce bone resorption, was 15-fold higher during hibernation. Serum calcium concentration was unchanged between hibernation and non-hibernation seasons. Suppressed and balanced bone resorption and formation in hibernating bears contributes to energy conservation, eucalcemia and the preservation of bone mass and strength, allowing bears to survive prolonged periods of extreme environmental conditions, nutritional deprivation and anuria.
Collapse
Affiliation(s)
- Meghan McGee-Lawrence
- Department of Cellular Biology and Anatomy, Georgia Regents University, Augusta, GA 30912, USA
| | - Patricia Buckendahl
- Center for Alcohol Studies, Rutgers University, New Brunswick, NJ 08901, USA
| | - Caren Carpenter
- Department of Orthopaedics and Rehabilitation, Yale University, New Haven, CT 06520, USA
| | - Kim Henriksen
- Nordic Bioscience Biomarkers and Research, Herlev, Denmark
| | - Michael Vaughan
- Department of Fish and Wildlife Conservation, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Seth Donahue
- Department of Mechanical Engineering, Colorado State University, Fort Collins, CO 80523, USA
| |
Collapse
|
27
|
Bloomfield SA, Martinez DA, Boudreaux RD, Mantri AV. Microgravity Stress: Bone and Connective Tissue. Compr Physiol 2016; 6:645-86. [PMID: 27065165 DOI: 10.1002/cphy.c130027] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The major alterations in bone and the dense connective tissues in humans and animals exposed to microgravity illustrate the dependency of these tissues' function on normal gravitational loading. Whether these alterations depend solely on the reduced mechanical loading of zero g or are compounded by fluid shifts, altered tissue blood flow, radiation exposure, and altered nutritional status is not yet well defined. Changes in the dense connective tissues and intervertebral disks are generally smaller in magnitude but occur more rapidly than those in mineralized bone with transitions to 0 g and during recovery once back to the loading provided by 1 g conditions. However, joint injuries are projected to occur much more often than the more catastrophic bone fracture during exploration class missions, so protecting the integrity of both tissues is important. This review focuses on the research performed over the last 20 years in humans and animals exposed to actual spaceflight, as well as on knowledge gained from pertinent ground-based models such as bed rest in humans and hindlimb unloading in rodents. Significant progress has been made in our understanding of the mechanisms for alterations in bone and connective tissues with exposure to microgravity, but intriguing questions remain to be solved, particularly with reference to biomedical risks associated with prolonged exploration missions.
Collapse
Affiliation(s)
- Susan A Bloomfield
- Department of Health & Kinesiology, Texas A&M University, College Station, Texas, USA
| | - Daniel A Martinez
- Department of Mechanical Engineering, University of Houston, Houston, Texas, USA
| | - Ramon D Boudreaux
- Biomedical Engineering, Texas A&M University, College Station, Texas, USA
| | - Anita V Mantri
- Department of Health & Kinesiology, Texas A&M University, College Station, Texas, USA.,Health Science Center School of Medicine, Texas A&M University, College Station, Texas, USA
| |
Collapse
|
28
|
Wojda SJ, Gridley RA, McGee-Lawrence ME, Drummer TD, Hess A, Kohl F, Barnes BM, Donahue SW. Arctic Ground Squirrels Limit Bone Loss during the Prolonged Physical Inactivity Associated with Hibernation. Physiol Biochem Zool 2015; 89:72-80. [PMID: 27082526 DOI: 10.1086/684619] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Prolonged disuse (e.g., physical inactivity) typically results in increased bone porosity, decreased mineral density, and decreased bone strength, leading to increased fracture risk in many mammals. However, bears, marmots, and two species of ground squirrels have been shown to preserve macrostructural bone properties and bone strength during long seasons of hibernation while they remain mostly inactive. Some small hibernators (e.g., 13-lined ground squirrels) show microstructural bone loss (i.e., osteocytic osteolysis) during hibernation, which is not seen in larger hibernators (e.g., bears and marmots). Arctic ground squirrels (Urocitellus parryii) are intermediate in size between 13-lined ground squirrels and marmots and are perhaps the most extreme rodent hibernator, hibernating for up to 8 mo annually with body temperatures below freezing. The goal of this study was to quantify the effects of hibernation and inactivity on cortical and trabecular bone properties in arctic ground squirrels. Cortical bone geometrical properties (i.e., thickness, cross-sectional area, and moment of inertia) at the midshaft of the femur were not different in animals sampled over the hibernation and active seasons. Femoral ultimate stress tended to be lower in hibernators than in summer animals, but toughness was not affected by hibernation. The area of osteocyte lacunae was not different between active and hibernating animals. There was an increase in osteocytic lacunar porosity in the hibernation group due to increased lacunar density. Trabecular bone volume fraction in the proximal tibia was unexpectedly greater in the hibernation group than in the active group. This study shows that, similar to other hibernators, arctic ground squirrels are able to preserve many bone properties during hibernation despite being physically inactive for up to 8 mo.
Collapse
|
29
|
Lin W, Ezura Y, Izu Y, Aryal A.C S, Kawasaki M, Na Mahasarakham Chantida P, Moriyama K, Noda M. Profilin Expression Is Regulated by Bone Morphogenetic Protein (BMP) in Osteoblastic Cells. J Cell Biochem 2015; 117:621-8. [DOI: 10.1002/jcb.25310] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2015] [Accepted: 08/11/2015] [Indexed: 12/31/2022]
Affiliation(s)
- Wanting Lin
- Department of Molecular Pharmacology; Medical Research Institute; Tokyo Medical and Dental University; Tokyo Japan
- Department of Maxillofacial Orthognathics; Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University; Tokyo Japan
| | - Yoichi Ezura
- Department of Molecular Pharmacology; Medical Research Institute; Tokyo Medical and Dental University; Tokyo Japan
| | - Yayoi Izu
- Department of Molecular Pharmacology; Medical Research Institute; Tokyo Medical and Dental University; Tokyo Japan
| | - Smriti Aryal A.C
- Department of Molecular Pharmacology; Medical Research Institute; Tokyo Medical and Dental University; Tokyo Japan
| | - Makiri Kawasaki
- Department of Molecular Pharmacology; Medical Research Institute; Tokyo Medical and Dental University; Tokyo Japan
| | | | - Keiji Moriyama
- Department of Maxillofacial Orthognathics; Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University; Tokyo Japan
| | - Masaki Noda
- Department of Molecular Pharmacology; Medical Research Institute; Tokyo Medical and Dental University; Tokyo Japan
| |
Collapse
|
30
|
Bauman WA, Cirnigliaro CM, La Fountaine MF, Martinez L, Kirshblum SC, Spungen AM. Zoledronic acid administration failed to prevent bone loss at the knee in persons with acute spinal cord injury: an observational cohort study. J Bone Miner Metab 2015; 33:410-21. [PMID: 25158630 DOI: 10.1007/s00774-014-0602-x] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Accepted: 05/08/2014] [Indexed: 01/23/2023]
Abstract
After acute spinal cord injury (SCI), rapid depletion of the sublesional skeleton occurs, particularly at the distal femur and proximal tibia. Subsequently, fragility fractures of the knee may occur. We determined the efficacy of zoledronic acid to prevent sublesional bone mineral density (BMD) loss at 6 and 12 months after acute SCI. Thirteen subjects with acute motor-complete SCI were prospectively studied: 6 patients received zoledronic acid (5 mg) and 7 subjects did not receive the drug (controls). Zoledronic acid was administered intravenously within 16 weeks of acute injury. Areal BMD was performed by dual energy X-ray absorptiometry at baseline, 6, and 12 months after administration of drug. The treatment group demonstrated sparing of BMD at the total hip at month 6 (p < 0.0006) and at month 12 (p < 0.01). In contrast to the findings at the hip, the treatment group had a greater loss of BMD compared to the control group at the distal femur and proximal tibia at month 6 (-7.9% ± 3.4 vs.-2.7% ± 5.0, respectively, p = 0.054; and -10.5% ± 6.4 vs. -4.8% ± 6.8, respectively, p = NS) and at month 12 (-18.5% ± 3.9 vs. -8.4% ± 7.2, respectively, p = 0.01; and -20.4% ± 8.8 vs.-7.9% ± 12.3, respectively, p = 0.06). A single dose of zoledronic acid administered soon after acute SCI reduced the %BMD loss at the hip, but appeared to have no effect to prevent %BMD loss at the knee, the site where fracture risk is greatest in persons with SCI.
Collapse
Affiliation(s)
- William A Bauman
- VA RR&D National Center of Excellence for the Medical Consequences of Spinal Cord Injury, James J. Peters VA Medical Center, 130 West Kingsbridge Road, Bronx, NY, 10468, USA,
| | | | | | | | | | | |
Collapse
|
31
|
Cardoso L, Schaffler MB. Changes of elastic constants and anisotropy patterns in trabecular bone during disuse-induced bone loss assessed by poroelastic ultrasound. J Biomech Eng 2014; 137:1944581. [PMID: 25412022 DOI: 10.1115/1.4029179] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Accepted: 11/20/2014] [Indexed: 11/08/2022]
Abstract
Currently, the approach most widely used to examine bone loss is the measurement of bone mineral density (BMD) using dual X-ray absorptiometry (DXA). However, bone loss due to immobilization creates changes in bone microarchitecture, which in turn are related to changes in bone mechanical function and competence to resist fracture.Unfortunately, the relationship between microarchitecture and mechanical function within the framework of immobilization and antiresorptive therapy has not being fully investigated. The goal of the present study was to investigate the structure–function relationship in trabecular bone in the real-world situations of a rapidly evolving osteoporosis(disuse), both with and without antiresorptive treatment. We evaluated the structure–function relationship in trabecular bone after bone loss (disuse-induced osteoporosis)and bisphosphonate treatment (antiresorptive therapy using risedronate) in canine trabecular bone using lCT and ultrasound wave propagation. Microstructure values determined from lCT images were used into the anisotropic poroelastic model of wave propagation in order to compute the apparent elastic constants (EC) and elastic anisotropy pattern of bone. Immobilization resulted in a significant reduction in trabecular thickness (Tb.Th) and bone volume fraction (BV/TV), while risedronate treatment combined with immobilization exhibited a lesser reduction in Tb.Th and BV/TV, suggesting that risedronate treatment decelerates bone loss, but it was unable to fully stop it. Risedronate treatment also increased the tissue mineral density (TMD), which when combined with the decrease in Tb.Th and BV/TV may explain the lack of significant differences invBMD in both immobilization and risedronate treated groups. Interestingly, changes inapparent EC were much stronger in the superior–inferior (SI) direction than in the medial–lateral (ML) and anterior–posterior (AP) anatomical directions, producing changes in elastic anisotropy patterns. When data were pooled together, vBMD was able to explain 58% of ultrasound measurements variability, a poroelastic wave propagation analytical model (i.e., BMD modulated by fabric directionality) was able to predict 81%of experimental wave velocity variability, and also explained 91% of apparent EC and changes in elastic anisotropy patterns. Overall, measurements of vBMD were unable to distinguish changes in apparent EC due to immobilization or risedronate treatment.However, anisotropic poroelastic ultrasound (PEUS) wave propagation was able to distinguish functional changes in apparent EC and elastic anisotropy patterns due to immobilization and antiresorptive therapy, providing an enhanced discrimination of anisotropic bone loss and the structure–function relationship in immobilized and risedronate-treated bone, beyond vBMD.
Collapse
|
32
|
Naringin prevents ovariectomy-induced osteoporosis and promotes osteoclasts apoptosis through the mitochondria-mediated apoptosis pathway. Biochem Biophys Res Commun 2014; 452:629-35. [DOI: 10.1016/j.bbrc.2014.08.117] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Accepted: 08/24/2014] [Indexed: 11/30/2022]
|
33
|
Bauman WA, Cardozo CP. Osteoporosis in individuals with spinal cord injury. PM R 2014; 7:188-201; quiz 201. [PMID: 25171878 DOI: 10.1016/j.pmrj.2014.08.948] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Accepted: 08/21/2014] [Indexed: 02/07/2023]
Abstract
The pathophysiology, clinical considerations, and relevant experimental findings with regard to osteoporosis in individuals with spinal cord injury (SCI) will be discussed. The bone loss that occurs acutely after more neurologically motor complete SCI is unique for its sublesional skeletal distribution and rate, at certain skeletal sites approaching 1% of bone mineral density per week, and its resistance to currently available treatments. The areas of high bone loss include the distal femur, proximal tibia, and more distal boney sites. Evidence from a study performed in monozygotic twins discordant for SCI indicates that sublesional bone loss in the twin with SCI increases for several decades, strongly suggesting that the heightened net bone loss after SCI may persist for an extended period of time. The increased frequency of fragility fracture after paralysis will be discussed, and a few risk factors for such fractures after SCI will be examined. Because vitamin D deficiency, regardless of disability, is a relevant consideration for bone health, as well as an easily reversible condition, the increased prevalence of and treatment target values for vitamin D in this deficiency state in the SCI population will be reviewed. Pharmacological and mechanical approaches to preserving bone integrity in persons with acute and chronic SCI will be reviewed, with emphasis placed on efficacy and practicality. Emerging osteoanabolic agents that improve functioning of WNT/β-catenin signaling after paralysis will be introduced as therapeutic interventions that may hold promise.
Collapse
Affiliation(s)
- William A Bauman
- Department of Veterans Affairs Rehabilitation Research & Development Service, National Center of Excellence for the Medical Consequences of Spinal Cord Injury, James J. Peters Veterans Affairs Medical Center, 130 West Kingsbridge Road, Bronx, NY 10468; Medical Service, James J. Peters VA Medical Center, Bronx, NY; Departments of Medicine and Rehabilitation Medicine, The Icahn School of Medicine at Mount Sinai, New York, NY∗.
| | - Christopher P Cardozo
- Department of Veterans Affairs Rehabilitation Research & Development Service, National Center of Excellence for the Medical Consequences of Spinal Cord Injury, James J. Peters Veterans Affairs Medical Center, Bronx, NY; Medical Service, James J. Peters VA Medical Center, Bronx, NY; Departments of Medicine and Rehabilitation Medicine, The Icahn School of Medicine at Mount Sinai, New York, NY(†)
| |
Collapse
|
34
|
Doherty AH, Florant GL, Donahue SW. Endocrine regulation of bone and energy metabolism in hibernating mammals. Integr Comp Biol 2014; 54:463-83. [PMID: 24556365 DOI: 10.1093/icb/icu001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Precise coordination among organs is required to maintain homeostasis throughout hibernation. This is particularly true in balancing bone remodeling processes (bone formation and resorption) in hibernators experiencing nutritional deprivation and extreme physical inactivity, two factors normally leading to pronounced bone loss in non-hibernating mammals. In recent years, important relationships between bone, fat, reproductive, and brain tissues have come to light. These systems share interconnected regulatory mechanisms of energy metabolism that potentially protect the skeleton during hibernation. This review focuses on the endocrine and neuroendocrine regulation of bone/fat/energy metabolism in hibernators. Hibernators appear to have unique mechanisms that protect musculoskeletal tissues while catabolizing their abundant stores of fat. Furthermore, the bone remodeling processes that normally cause disuse-induced bone loss in non-hibernators are compared to bone remodeling processes in hibernators, and possible adaptations of the bone signaling pathways that protect the skeleton during hibernation are discussed. Understanding the biological mechanisms that allow hibernators to survive the prolonged disuse and fasting associated with extreme environmental challenges will provide critical information regarding the limit of convergence in mammalian systems and of skeletal plasticity, and may contribute valuable insight into the etiology and treatment of human diseases.
Collapse
Affiliation(s)
- Alison H Doherty
- *Department of Biology, Colorado State University, Fort Collins, CO 80523-1620, USA; Department of Mechanical Engineering, Colorado State University, Fort Collins, CO 80523-1620, USA*Department of Biology, Colorado State University, Fort Collins, CO 80523-1620, USA; Department of Mechanical Engineering, Colorado State University, Fort Collins, CO 80523-1620, USA
| | - Gregory L Florant
- *Department of Biology, Colorado State University, Fort Collins, CO 80523-1620, USA; Department of Mechanical Engineering, Colorado State University, Fort Collins, CO 80523-1620, USA
| | - Seth W Donahue
- *Department of Biology, Colorado State University, Fort Collins, CO 80523-1620, USA; Department of Mechanical Engineering, Colorado State University, Fort Collins, CO 80523-1620, USA
| |
Collapse
|
35
|
Oppl B, Michitsch G, Misof B, Kudlacek S, Donis J, Klaushofer K, Zwerina J, Zwettler E. Low bone mineral density and fragility fractures in permanent vegetative state patients. J Bone Miner Res 2014; 29:1096-100. [PMID: 24470043 DOI: 10.1002/jbmr.2122] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Revised: 10/08/2013] [Accepted: 10/23/2013] [Indexed: 12/24/2022]
Abstract
Disuse of the musculoskeletal system causes bone loss. Whether patients in vegetative state, a dramatic example of immobilization after severe brain injury, suffer from bone loss and fractures is currently unknown. Serum markers of bone turnover, bone mineral density (BMD) measurements, and clinical data were cross-sectionally analyzed in 30 consecutive vegetative state patients of a dedicated apallic care unit between 2003 and 2007 and compared with age- and sex-matched healthy individuals. Vegetative state patients showed low calcium levels and vitamin D deficiency compared with healthy controls. Serum bone turnover markers revealed high turnover as evidenced by markedly elevated carboxy-terminal telopeptide of type I collagen (β-crosslaps) and increased levels of alkaline phosphatase. BMD measured by dual-energy X-ray absorptiometry (DXA) scanning showed strongly decreased T- and Z-scores for hip and spine. Over a period of 5 years, 8 fragility fractures occurred at peripheral sites in 6 of 30 patients (n = 3 femur, n = 2 tibia, n = 2 fibula, n = 1 humerus). In conclusion, high bone turnover and low BMD is highly prevalent in vegetative state patients, translating into a clinically relevant problem as shown by fragility fractures in 20% of patients over a time period of 5 years. .
Collapse
Affiliation(s)
- Bastian Oppl
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of WGKK and AUVA Trauma Centre Meidling, 1st Medical Department, Hanusch Hospital, Vienna, Austria
| | | | | | | | | | | | | | | |
Collapse
|
36
|
SIU WINGSUM, KO CHUNHAY, HUNG LEUNGKIM, LAU CHINGPO, LAU CLARABIKSAN, FUNG KWOKPUI, LEUNG PINGCHUNG. Effect of anti-osteoporotic agents on the prevention of bone loss in unloaded bone. Mol Med Rep 2013; 8:1188-94. [DOI: 10.3892/mmr.2013.1647] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Accepted: 06/20/2013] [Indexed: 11/05/2022] Open
|
37
|
Wojda SJ, Weyland DR, Gray SK, Mcgee-Lawrence ME, Drummer TD, Donahue SW. Black Bears With Longer Disuse (Hibernation) Periods Have Lower Femoral Osteon Population Density and Greater Mineralization and Intracortical Porosity. Anat Rec (Hoboken) 2013; 296:1148-53. [DOI: 10.1002/ar.22720] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Accepted: 04/13/2013] [Indexed: 11/09/2022]
Affiliation(s)
- Samantha J. Wojda
- Deptartment of Mechanical Engineering; Colorado State University, Flint Animal Cancer Center; 300 West Drake Road Fort Collins Colorado
| | - David R. Weyland
- Deptartment of Biomedical Engineering; Michigan Tech University; 1400 Townsend Dr. Houghton Michigan
| | - Sarah K. Gray
- Deptartment of Biomedical Engineering; Michigan Tech University; 1400 Townsend Dr. Houghton Michigan
| | | | - Thomas D. Drummer
- Deptartment of Mathematical Sciences; Michigan Tech University; 1400 Townsend Dr. Houghton Michigan
| | - Seth W. Donahue
- Deptartment of Mechanical Engineering; Colorado State University, Flint Animal Cancer Center; 300 West Drake Road Fort Collins Colorado
| |
Collapse
|
38
|
Belluci MM, Schoenmaker T, Rossa-Junior C, Orrico SR, de Vries TJ, Everts V. Magnesium deficiency results in an increased formation of osteoclasts. J Nutr Biochem 2013; 24:1488-98. [PMID: 23517915 DOI: 10.1016/j.jnutbio.2012.12.008] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Revised: 12/16/2012] [Accepted: 12/19/2012] [Indexed: 11/28/2022]
Abstract
Magnesium (Mg(2+)) deficiency is a frequently occurring disorder that leads to loss of bone mass, abnormal bone growth and skeletal weakness. It is not clear whether Mg(2+) deficiency affects the formation and/or activity of osteoclasts. We evaluated the effect of Mg(2+) restriction on these parameters. Bone marrow cells from long bone and jaw of mice were seeded on plastic and on bone in medium containing different concentrations of Mg(2+) (0.8 mM which is 100% of the normal value, 0.4, 0.08 and 0 mM). The effect of Mg(2+) deficiency was evaluated on osteoclast precursors for their viability after 3 days and proliferation rate after 3 and 6 days, as was mRNA expression of osteoclastogenesis-related genes and Mg(2+)-related genes. After 6 days of incubation, the number of tartrate resistant acid phosphatase-positive (TRACP(+)) multinucleated cells was determined, and the TRACP activity of the medium was measured. Osteoclastic activity was assessed at 8 days by resorption pit analysis. Mg(2+) deficiency resulted in increased numbers of osteoclast-like cells, a phenomenon found for both types of marrow. Mg(2+) deficiency had no effect on cell viability and proliferation. Increased osteoclastogenesis due to Mg(2+) deficiency was reflected in higher expression of osteoclast-related genes. However, resorption per osteoclast and TRACP activity were lower in the absence of Mg(2+). In conclusion, Mg(2+) deficiency augmented osteoclastogenesis but appeared to inhibit the activity of these cells. Together, our in vitro data suggest that altered osteoclast numbers and activity may contribute to the skeletal phenotype as seen in Mg(2+) deficient patients.
Collapse
Affiliation(s)
- Marina M Belluci
- Department of Diagnosis and Surgery, School of Dentistry at Araraquara-UNESP-Universidad Estadual Paulista, Araraquara, São Paulo, Brazil.
| | | | | | | | | | | |
Collapse
|
39
|
Qi W, Yan YB, Lei W, Wu ZX, Zhang Y, Liu D, Shi L, Cao PC, Liu N. Prevention of disuse osteoporosis in rats by Cordyceps sinensis extract. Osteoporos Int 2012; 23:2347-57. [PMID: 22159671 DOI: 10.1007/s00198-011-1842-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2011] [Accepted: 11/03/2011] [Indexed: 10/14/2022]
Abstract
UNLABELLED Cordyceps sinensis has been known as a traditional medicine in China, and C. sinensis plus strontium could prevent osteoporosis in ovariectomized rats. The present study shows that daily oral administration of C. sinensis at higher doses in adult hind limb suspension rats can prevent disuse-induced bone loss and deterioration of trabecular microarchitecture. INTRODUCTION Cordyceps sinensis induces estradiol production and prevents osteoporosis in ovariectomized rats. This study was to examine whether C. sinensis can prevent disuse-induced osteoporosis. METHODS Rats were randomly divided into six groups, and five groups were treated with hind limb suspension (HLS). One HLS group received alendronate (2.0 mg/kg/day) orally, and to the three other HLS groups to each group, a different amount of C. sinensis (100, 300, and 500 mg/kg/day) was orally administered for 8 weeks before and after HLS. The remaining HLS group was set as a control without treatment. Each group consisted of 10 males and females. The body weights, biochemical parameters in serum and urine, bone mineral density (BMD), bone mineral content (BMC), mechanical testing, and bone microarchitecture were examined. RESULTS Treatments with higher C. sinensis dosage (300 and 500 mg/kg/day) or alendronate had a positive effect on body weights, mechanical strength, BMD, and BMC compared to the other HLS groups. C. sinensis decreased markers of bone turnover dose dependently and increased the osteocalcin levels in HLS rats. The result of micro-CT analysis from the L4 vertebra showed that C. sinensis (500 mg/kg) significantly prevented the reduction of the bone volume fraction, connectivity density, trabeculae number, and thickness as well as improved the trabeculae separation and structure model index in HLS rats. CONCLUSIONS The present study demonstrates that administration of C. sinensis at higher doses over an 8-week period can prevent the disuse osteoporosis in rats. It implies that C. sinensis might be an alternative therapy for prevention of disuse-induced osteoporosis also in humans.
Collapse
Affiliation(s)
- W Qi
- Department of Orthopaedics, Xijing Hospital, The Fourth Military Medical University, No 15 Changle West Road, Xi'an, China
| | | | | | | | | | | | | | | | | |
Collapse
|
40
|
Maldonado N, Kelly-Arnold A, Vengrenyuk Y, Laudier D, Fallon JT, Virmani R, Cardoso L, Weinbaum S. A mechanistic analysis of the role of microcalcifications in atherosclerotic plaque stability: potential implications for plaque rupture. Am J Physiol Heart Circ Physiol 2012; 303:H619-28. [PMID: 22777419 DOI: 10.1152/ajpheart.00036.2012] [Citation(s) in RCA: 169] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The role of microcalcifications (μCalcs) in the biomechanics of vulnerable plaque rupture is examined. Our laboratory previously proposed (Ref. 44), using a very limited tissue sample, that μCalcs embedded in the fibrous cap proper could significantly increase cap instability. This study has been greatly expanded. Ninety-two human coronary arteries containing 62 fibroatheroma were examined using high-resolution microcomputed tomography at 6.7-μm resolution and undecalcified histology with special emphasis on calcified particles <50 μm in diameter. Our results reveal the presence of thousands of μCalcs, the vast majority in lipid pools where they are not dangerous. However, 81 μCalcs were also observed in the fibrous caps of nine of the fibroatheroma. All 81 of these μCalcs were analyzed using three-dimensional finite-element analysis, and the results were used to develop important new clinical criteria for cap stability. These criteria include variation of the Young's modulus of the μCalc and surrounding tissue, μCalc size, and clustering. We found that local tissue stress could be increased fivefold when μCalcs were closely spaced, and the peak circumferential stress in the thinnest nonruptured cap (66 μm) if no μCalcs were present was only 107 kPa, far less than the proposed minimum rupture threshold of 300 kPa. These results and histology suggest that there are numerous μCalcs < 15 μm in the caps, not visible at 6.7-μm resolution, and that our failure to find any nonruptured caps between 30 and 66 μm is a strong indication that many of these caps contained μCalcs.
Collapse
Affiliation(s)
- Natalia Maldonado
- Department of Biomedical Engineering, The City College of New York, The City University of New York, New York, New York 10031, USA
| | | | | | | | | | | | | | | |
Collapse
|
41
|
Sheng ZF, Ma YL, Tong D, Fang DY, Liang QC, Liu LH, Zhang J, Liao EY. Strontium ranelate prevents bone loss in a rat model of localized muscle paralysis. Ann Biomed Eng 2012; 40:657-65. [PMID: 22237860 DOI: 10.1007/s10439-011-0406-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2011] [Accepted: 09/09/2011] [Indexed: 11/28/2022]
Abstract
Twenty-one 3.5-month-old female Sprague-Dawley rats were randomly assigned to three groups: BTX group, in which each rat received a single intramuscular injection of 2 U of Clostridium botulinum toxin (BTX) in the quadriceps femoris muscle of the right hind limb; BTX + SR group, in which each rat received a BTX injection and a dose of strontium ranelate (dose level of 625 mg/kg/day); and the control group. All the rats were killed at 9 weeks post-treatment. It was showed that BTX-induced rats a rapid loss of body weight in the first 3 weeks, after which their body weight showed a slow increase similar to that observed in the control rats. The net body weight loss was mainly attributed to muscle atrophy. BTX caused remarkable bone degradation in either the trabecular bone or the cortical bone of the disuse femur. The deteriorations in the bone mass and bone microstructure were locally limited and could be prevented by strontium ranelate treatment. Biomechanical analysis showed that strontium ranelate treatment improved the mechanical performance of the tibia in BTX-treated rats. It was showed that a clinical-corresponding dose of strontium ranelate could prevent bone loss in long-term immobilized rats.
Collapse
Affiliation(s)
- Zhi-Feng Sheng
- Institute of Metabolism and Endocrinology, The Second Xiang-Ya Hospital, Central South University, 410011 Hunan, People's Republic of China
| | | | | | | | | | | | | | | |
Collapse
|
42
|
Wojda SJ, McGee-Lawrence ME, Gridley RA, Auger J, Black HL, Donahue SW. Yellow-bellied marmots (Marmota flaviventris) preserve bone strength and microstructure during hibernation. Bone 2012; 50:182-8. [PMID: 22037004 PMCID: PMC3489026 DOI: 10.1016/j.bone.2011.10.013] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2011] [Revised: 09/12/2011] [Accepted: 10/11/2011] [Indexed: 11/23/2022]
Abstract
Reduced skeletal loading typically results in decreased bone strength and increased fracture risk for humans and many other animals. Previous studies have shown bears are able to prevent bone loss during the disuse that occurs during hibernation. Studies with smaller hibernators, which arouse intermittently during hibernation, show that they may lose bone at the microstructural level. These small hibernators, like bats and squirrels, do not utilize intracortical remodeling. However, slightly larger mammals like marmots do. In this study we examined the effects of hibernation on bone structural, mineral, and mechanical properties in yellow-bellied marmots (Marmota flaviventris). This was done by comparing cortical bone properties in femurs and trabecular bone properties in tibias from marmots killed before hibernation (fall) and after hibernation (spring). Age data were not available for this study; however, based on femur length the post-hibernation marmots were larger than the pre-hibernation marmots. Thus, cross-sectional properties were normalized by allometric functions of bone length for comparisons between pre- and post-hibernation. Cortical thickness and normalized cortical area were higher in post-hibernation samples; no other normalized cross-sectional properties were different. No cortical bone microstructural loss was evident in osteocyte lacunar measurements, intracortical porosity, or intracortical remodeling cavity density. Osteocyte lacunar area, porosity, and density were surprisingly lower in post-hibernation samples. Trabecular bone volume fraction was not different between pre- and post-hibernation. Measures of both trabecular and cortical bone mineral content were higher in post-hibernation samples. Three-point bending failure load, failure energy, elastic energy, ultimate stress, and yield stress were all higher in post-hibernation samples. These results support the idea that, like bears, marmots are able to prevent disuse osteoporosis during hibernation, thus preventing increased fracture risk and promoting survival of the extreme environmental conditions that occur in hibernation.
Collapse
Affiliation(s)
- Samantha J Wojda
- Department of Mechanical Engineering and Engineering Mechanics, Michigan Technological University, Townsend Drive, Houghton, MI 49931, USA
| | | | | | | | | | | |
Collapse
|
43
|
McGee-Lawrence ME, Stoll DM, Mantila ER, Fahrner BK, Carey HV, Donahue SW. Thirteen-lined ground squirrels (Ictidomys tridecemlineatus) show microstructural bone loss during hibernation but preserve bone macrostructural geometry and strength. ACTA ACUST UNITED AC 2011; 214:1240-7. [PMID: 21430199 DOI: 10.1242/jeb053520] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Lack of activity causes bone loss In most animals. Hibernating bears have physiological processes to prevent cortical and trabecular bone loss associated with reduced physical activity, but different mechanisms of torpor among hibernating species may lead to differences in skeletal responses to hibernation. There are conflicting reports regarding whether small mammals experience bone loss during hibernation. To investigate this phenomenon, we measured cortical and trabecular bone properties in physically active and hibernating juvenile and adult 13-lined ground squirrels (Ictidomys tridecemlineatus, previous genus name Spermophilus). Cortical bone geometry, strength and mineral content were similar in hibernating compared with active squirrels, suggesting that hibernation did not cause macrostructural cortical bone loss. Osteocyte lacunar size increased (linear regression, P=0.001) over the course of hibernation in juvenile squirrels, which may indicate an osteocytic role in mineral homeostasis during hibernation. Osteocyte lacunar density and porosity were greater (+44 and +59%, respectively; P<0.0001) in hibernating compared with active squirrels, which may reflect a decrease in osteoblastic activity (per cell) during hibernation. Trabecular bone volume fraction in the proximal tibia was decreased (-20%; P=0.028) in hibernating compared with physically active adult squirrels, but was not different between hibernating and active juvenile squirrels. Taken together, these data suggest that 13-lined ground squirrels may be unable to prevent microstructural losses of cortical and trabecular bone during hibernation, but importantly may possess a biological mechanism to preserve cortical bone macrostructure and strength during hibernation, thus preventing an increased risk of bone fracture during remobilization in the spring.
Collapse
|
44
|
Endocrine Aspects of Duchenne Muscular Dystrophy. Neuromuscul Disord 2011; 21:298-303. [DOI: 10.1016/j.nmd.2011.02.006] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2010] [Revised: 01/24/2011] [Accepted: 02/02/2011] [Indexed: 11/21/2022]
|
45
|
Via MA, Potenza MV, Hollander J, Liu X, Peng Y, Li J, Sun L, Zaidi M, Mechanick JI. Intravenous Ibandronate Acutely Reduces Bone Hyperresorption in Chronic Critical Illness. J Intensive Care Med 2011; 27:312-8. [DOI: 10.1177/0885066611402156] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Michael A. Via
- Division of Endocrinology and Metabolism, Albert Einstein College of Medicine, Beth Israel Medical Center, New York, NY, USA
| | | | - Jason Hollander
- Princeton Endocrinology, Princeton, New Jersey, Princeton, NJ, USA
| | - Xuan Liu
- The Mount Sinai Bone Program, Division of Endocrinology, Diabetes and Bone Disease, Mount Sinai School of Medicine, New York, NY, USA
| | - Yuanzhen Peng
- The Mount Sinai Bone Program, Division of Endocrinology, Diabetes and Bone Disease, Mount Sinai School of Medicine, New York, NY, USA
| | - Jianhua Li
- The Mount Sinai Bone Program, Division of Endocrinology, Diabetes and Bone Disease, Mount Sinai School of Medicine, New York, NY, USA
| | - Li Sun
- Division of Endocrinology, Diabetes and Bone Disease, Mount Sinai School of Medicine, New York, NY, USA
| | - Mone Zaidi
- The Mount Sinai Bone Program, Division of Endocrinology, Diabetes and Bone Disease, Mount Sinai School of Medicine, New York, NY, USA
| | - Jeffrey I. Mechanick
- Division of Endocrinology, Diabetes and Bone Disease, Mount Sinai School of Medicine, New York, NY, USA
| |
Collapse
|
46
|
Bergmann P, Body JJ, Boonen S, Boutsen Y, Devogelaer JP, Goemaere S, Kaufman J, Reginster JY, Rozenberg S. Loading and skeletal development and maintenance. J Osteoporos 2010; 2011:786752. [PMID: 21209784 PMCID: PMC3010667 DOI: 10.4061/2011/786752] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2010] [Accepted: 11/06/2010] [Indexed: 12/12/2022] Open
Abstract
Mechanical loading is a major regulator of bone mass and geometry. The osteocytes network is considered the main sensor of loads, through the shear stress generated by strain induced fluid flow in the lacuno-canalicular system. Intracellular transduction implies several kinases and phosphorylation of the estrogen receptor. Several extra-cellular mediators, among which NO and prostaglandins are transducing the signal to the effector cells. Disuse results in osteocytes apoptosis and rapid imbalanced bone resorption, leading to severe osteoporosis. Exercising during growth increases peak bone mass, and could be beneficial with regards to osteoporosis later in life, but the gain could be lost if training is abandoned. Exercise programs in adults and seniors have barely significant effects on bone mass and geometry at least at short term. There are few data on a possible additive effect of exercise and drugs in osteoporosis treatment, but disuse could decrease drugs action. Exercise programs proposed for bone health are tedious and compliance is usually low. The most practical advice for patients is to walk a minimum of 30 to 60 minutes per day. Other exercises like swimming or cycling have less effect on bone, but could reduce fracture risk indirectly by maintaining muscle mass and force.
Collapse
Affiliation(s)
- P. Bergmann
- Department of Nuclear Medicine, Laboratory of Clinical Chemistry and Experimental Medicine, CHU Brugmann, Université Libre de Bruxelles, 4 Pl. Van Gehuchten, 1020 Brussels, Belgium,*P. Bergmann:
| | - J. J. Body
- Department of Medicine, CHU Brugmann, Université Libre de Bruxelles, 1020 Brussels, Belgium
| | - S. Boonen
- Division of Gerontology and Geriatrics, Center for Musculoskeletal Research, Department of Experimental Medicine, Catholic Leuven University, 3000 Leuven, Belgium
| | - Y. Boutsen
- Department of Rheumatology, Mont-Godinne University Hospital, Université Catholique de Louvain, 1200 Brussels, Belgium
| | - J. P. Devogelaer
- Rheumatology Unit, Saint-Luc University Hospital, Université Catholique de Louvain, 1200 Brussels, Belgium
| | - S. Goemaere
- Unit for Osteoporosis and Metabolic Bone Diseases, Ghent University Hospital, 9000 Ghent, Belgium
| | - J. Kaufman
- Unit for Osteoporosis and Metabolic Bone Diseases, Ghent University Hospital, 9000 Ghent, Belgium
| | - J. Y. Reginster
- Department of Public Health Sciences, University of Liège, 4000 Liège, Belgium
| | - S. Rozenberg
- Department of Gynaecology-Obstetrics, Free University of Brussels, 1090 Brussels, Belgium
| |
Collapse
|
47
|
Ozcivici E, Luu YK, Rubin CT, Judex S. Low-level vibrations retain bone marrow's osteogenic potential and augment recovery of trabecular bone during reambulation. PLoS One 2010; 5:e11178. [PMID: 20567514 PMCID: PMC2887365 DOI: 10.1371/journal.pone.0011178] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2010] [Accepted: 05/27/2010] [Indexed: 12/19/2022] Open
Abstract
Mechanical disuse will bias bone marrow stromal cells towards adipogenesis, ultimately compromising the regenerative capacity of the stem cell pool and impeding the rapid and full recovery of bone morphology. Here, it was tested whether brief daily exposure to high-frequency, low-magnitude vibrations can preserve the marrow environment during disuse and enhance the initiation of tissue recovery upon reambulation. Male C57BL/6J mice were subjected to hindlimb unloading (HU, n = 24), HU interrupted by weight-bearing for 15 min/d (HU+SHAM, n = 24), HU interrupted by low-level whole body vibrations (0.2 g, 90 Hz) for 15 min/d (HU+VIB, n = 24), or served as age-matched controls (AC, n = 24). Following 3 w of disuse, half of the mice in each group were released for 3 w of reambulation (RA), while the others were sacrificed. RA+VIB mice continued to receive vibrations for 15 min/d while RA+SHAM continued to receive sham loading. After disuse, HU+VIB mice had a 30% greater osteogenic marrow stromal cell population, 30% smaller osteoclast surface, 76% greater osteoblast surface but similar trabecular bone volume fraction compared to HU. After 3 w of reambulation, trabecular bone of RA+VIB mice had a 30% greater bone volume fraction, 51% greater marrow osteoprogenitor population, 83% greater osteoblast surfaces, 59% greater bone formation rates, and a 235% greater ratio of bone lining osteoblasts to marrow adipocytes than RA mice. A subsequent experiment indicated that receiving the mechanical intervention only during disuse, rather than only during reambulation, was more effective in altering trabecular morphology. These data indicate that the osteogenic potential of bone marrow cells is retained by low-magnitude vibrations during disuse, an attribute which may have contributed to an enhanced recovery of bone morphology during reambulation.
Collapse
Affiliation(s)
- Engin Ozcivici
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York, United States of America
| | - Yen K. Luu
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York, United States of America
| | - Clinton T. Rubin
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York, United States of America
| | - Stefan Judex
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York, United States of America
- * E-mail:
| |
Collapse
|
48
|
Ryder KM, Tanner SB, Carbone L, Williams JE, Taylor HM, Bush A, Pintea V, Watsky MA. Teriparatide is safe and effectively increases bone biomarkers in institutionalized individuals with osteoporosis. J Bone Miner Metab 2010; 28:233-9. [PMID: 19806302 DOI: 10.1007/s00774-009-0123-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2009] [Accepted: 08/12/2009] [Indexed: 10/20/2022]
Abstract
Institutionalized adults with severe developmental disabilities have a high rate of minimal trauma and appendicular fracture. There is little information about osteoporosis treatment in this population. In this efficacy and safety study, men and women with severe developmental disabilities and osteoporosis received 20 mcg teriparatide subcutaneously daily for 18-24 months. Markers of bone formation [procollagen type 1 intact N-terminal propeptide (P1NP)] and resorption [C-telopeptide (CTx)] were measured at three-month intervals. Serum calcium was measured at two-week intervals for 12 weeks and thereafter at three-month intervals. Twenty-seven individuals received at least one injection. The incidence of hypercalcemia was 11.1% but was persistent and led to medication discontinuation in only one participant. Biomarkers of bone formation increased rapidly, doubling by three months. At 12 months, P1NP and CTx remained elevated from baseline; P1NP had risen from 66.95 +/- 83.71 microg/l (mean +/- SD) to 142.42 +/- 113.85 microg/l (P = 0.05), and CTx had increased from 0.377 +/- 0.253 to 1.016 +/- 1.048 ng/ml (P = 0.01). The majority of participants had an increase in P1NP of over 10 microg/l. In conclusion, teriparatide is safe and effective in developmentally disabled institutionalized adults. Serial calcium measurements are warranted, particularly during the first three months of therapy.
Collapse
Affiliation(s)
- Kathryn M Ryder
- Department of Medicine, The University of Tennessee Health Science Center, Memphis, TN, USA.
| | | | | | | | | | | | | | | |
Collapse
|
49
|
McGee-Lawrence ME, Wojda SJ, Barlow LN, Drummer TD, Bunnell K, Auger J, Black HL, Donahue SW. Six months of disuse during hibernation does not increase intracortical porosity or decrease cortical bone geometry, strength, or mineralization in black bear (Ursus americanus) femurs. J Biomech 2009; 42:1378-1383. [PMID: 19450804 DOI: 10.1016/j.jbiomech.2008.11.039] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2008] [Revised: 10/31/2008] [Accepted: 11/03/2008] [Indexed: 11/26/2022]
Abstract
Disuse typically uncouples bone formation from resorption, leading to bone loss which compromises bone mechanical properties and increases the risk of bone fracture. Previous studies suggest that bears can prevent bone loss during long periods of disuse (hibernation), but small sample sizes have limited the conclusions that can be drawn regarding the effects of hibernation on bone structure and strength in bears. Here we quantified the effects of hibernation on structural, mineral, and mechanical properties of black bear (Ursus americanus) cortical bone by studying femurs from large groups of male and female bears (with wide age ranges) killed during pre-hibernation (fall) and post-hibernation (spring) periods. Bone properties that are affected by body mass (e.g. bone geometrical properties) tended to be larger in male compared to female bears. There were no differences (p>0.226) in bone structure, mineral content, or mechanical properties between fall and spring bears. Bone geometrical properties differed by less than 5% and bone mechanical properties differed by less than 10% between fall and spring bears. Porosity (fall: 5.5+/-2.2%; spring: 4.8+/-1.6%) and ash fraction (fall: 0.694+/-0.011; spring: 0.696+/-0.010) also showed no change (p>0.304) between seasons. Statistical power was high (>72%) for these analyses. Furthermore, bone geometrical properties and ash fraction (a measure of mineral content) increased with age and porosity decreased with age. These results support the idea that bears possess a biological mechanism to prevent disuse and age-related osteoporoses.
Collapse
Affiliation(s)
- Meghan E McGee-Lawrence
- Department of Biomedical Engineering, Michigan Technological University, 309 Minerals and Materials Engineering Building, 1400 Townsend Drive, Houghton, MI 49931, USA
| | - Samantha J Wojda
- Department of Biomedical Engineering, Michigan Technological University, 309 Minerals and Materials Engineering Building, 1400 Townsend Drive, Houghton, MI 49931, USA
| | - Lindsay N Barlow
- Department of Biomedical Engineering, Michigan Technological University, 309 Minerals and Materials Engineering Building, 1400 Townsend Drive, Houghton, MI 49931, USA
| | - Thomas D Drummer
- Department of Mathematical Sciences, Michigan Technological University, Houghton, MI 49931, USA
| | - Kevin Bunnell
- Utah Division of Wildlife Resources, 1594 W. North Temple, Salt Lake City, UT 84116, USA
| | - Janene Auger
- Department of Integrative Biology, 401 WIDB, Brigham Young University, Provo, UT 84602, USA
| | - Hal L Black
- Department of Integrative Biology, 401 WIDB, Brigham Young University, Provo, UT 84602, USA
| | - Seth W Donahue
- Department of Biomedical Engineering, Michigan Technological University, 309 Minerals and Materials Engineering Building, 1400 Townsend Drive, Houghton, MI 49931, USA.
| |
Collapse
|
50
|
McGee-Lawrence ME, Carey HV, Donahue SW. Mammalian hibernation as a model of disuse osteoporosis: the effects of physical inactivity on bone metabolism, structure, and strength. Am J Physiol Regul Integr Comp Physiol 2008; 295:R1999-2014. [PMID: 18843088 DOI: 10.1152/ajpregu.90648.2008] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Reduced skeletal loading typically leads to bone loss because bone formation and bone resorption become unbalanced. Hibernation is a natural model of musculoskeletal disuse because hibernating animals greatly reduce weight-bearing activity, and therefore, they would be expected to lose bone. Some evidence suggests that small mammals like ground squirrels, bats, and hamsters do lose bone during hibernation, but the mechanism of bone loss is unclear. In contrast, hibernating bears maintain balanced bone remodeling and preserve bone structure and strength. Differences in the skeletal responses of bears and smaller mammals to hibernation may be due to differences in their hibernation patterns; smaller mammals may excrete calcium liberated from bone during periodic arousals throughout hibernation, leading to progressive bone loss over time, whereas bears may have evolved more sophisticated physiological processes to recycle calcium, prevent hypercalcemia, and maintain bone integrity. Investigating the roles of neural and hormonal control of bear bone metabolism could give valuable insight into translating the mechanisms that prevent disuse-induced bone loss in bears into novel therapies for treating osteoporosis.
Collapse
Affiliation(s)
- Meghan E McGee-Lawrence
- Department of Biomedical Engineering, Michigan Technological University, 309 Minerals & Materials Engineering Bldg., 1400 Townsend Dr., Houghton, MI 49931, USA
| | | | | |
Collapse
|