1
|
Sidles SJ, Kelly RR, Kelly KD, Hathaway-Schrader JD, Khoo SK, Jones JA, Cray JJ, LaRue AC. Inescapable foot shock induces a PTSD-like phenotype and negatively impacts adult murine bone. Dis Model Mech 2024; 17:dmm050044. [PMID: 38131122 PMCID: PMC10820809 DOI: 10.1242/dmm.050044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 12/01/2023] [Indexed: 12/23/2023] Open
Abstract
Post-traumatic stress disorder (PTSD) is associated with osteopenia, osteoporosis and increased fracture risk in the clinical population. Yet, the development of preclinical models to study PTSD-induced bone loss remains limited. In this study, we present a previously unreported model of PTSD in adult female C57BL/6 mice, by employing inescapable foot shock and social isolation, that demonstrates high face and construct validity. A subset of mice exposed to this paradigm (i.e. PTSD mice) display long-term alterations in behavioral and inflammatory indices. Using three-dimensional morphometric calculations, cyclic reference point indentation (cRPI) testing and histological analyses, we find that PTSD mice exhibit loss of trabecular bone, altered bone material quality, and aberrant changes in bone tissue architecture and cellular activity. This adult murine model of PTSD exhibits clinically relevant changes in bone physiology and provides a valuable tool for investigating the cellular and molecular mechanisms underlying PTSD-induced bone loss.
Collapse
Affiliation(s)
- Sara J. Sidles
- Research Service, Ralph H. Johnson Department of Veterans Affairs Health Care System, Charleston, SC 29401, USA
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Ryan R. Kelly
- Research Service, Ralph H. Johnson Department of Veterans Affairs Health Care System, Charleston, SC 29401, USA
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Kirsten D. Kelly
- Research Service, Ralph H. Johnson Department of Veterans Affairs Health Care System, Charleston, SC 29401, USA
| | - Jessica D. Hathaway-Schrader
- Research Service, Ralph H. Johnson Department of Veterans Affairs Health Care System, Charleston, SC 29401, USA
- College of Dental Medicine, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Stephanie K. Khoo
- Research Service, Ralph H. Johnson Department of Veterans Affairs Health Care System, Charleston, SC 29401, USA
| | - Jeffrey A. Jones
- Research Service, Ralph H. Johnson Department of Veterans Affairs Health Care System, Charleston, SC 29401, USA
- Department of Surgery, Medical University of South Carolina, Charleston, SC 29425, USA
| | - James J. Cray
- Division of Anatomy, The Ohio State University, Columbus, OH 43210, USA
| | - Amanda C. LaRue
- Research Service, Ralph H. Johnson Department of Veterans Affairs Health Care System, Charleston, SC 29401, USA
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC 29425, USA
| |
Collapse
|
2
|
Sang W, Ural A. Evaluating the Role of Canalicular Morphology and Perilacunar Region Properties on Local Mechanical Environment of Lacunar-Canalicular Network Using Finite Element Modeling. J Biomech Eng 2023; 145:1156059. [PMID: 36629002 DOI: 10.1115/1.4056655] [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: 10/13/2022] [Accepted: 01/07/2023] [Indexed: 01/12/2023]
Abstract
Physiological and pathological processes such as aging, diseases, treatments, and lactation can alter lacunar-canalicular network (LCN) morphology and perilacunar region properties. These modifications can impact the mechanical environment of osteocytes which in turn can influence osteocyte mechanosensitivity and the remodeling process. In this study, we aim to evaluate how the modifications in the canalicular morphology, lacunar density, and the perilacunar region properties influence the local mechanical environment of LCN and the apparent bone properties using three-dimensional finite element (FE) modeling. The simulation results showed that a 50% reduction in perilacunar elastic modulus led to about 7% decrease in apparent elastic modulus of the bone. The increase in canalicular density, length, and diameter did not influence the strain amplification in the models but they increased the amount of highly strained bone around LCN. Change in lacunar density did not influence the strain amplification and the amount of highly strained regions on LCN surfaces. Reduction in perilacunar elastic modulus increased both the strain amplification and the volume of highly strained tissue around and on the surface of LCN. The FE models of LCN in this study can be utilized to quantify the influence of modifications in canalicular morphology, lacunar density, and perilacunar region properties on the apparent bone properties and the local mechanical environment of LCN. Although this is a numerical study with idealized models, it provides important information on how mechanical environment of osteocytes is influenced by the modifications in LCN morphology and perilacunar region properties due to physiological and pathological processes.
Collapse
Affiliation(s)
- Wen Sang
- Department of Mechanical Engineering, Villanova University, 800 Lancaster Avenue, Villanova, PA 19085
| | - Ani Ural
- Department of Mechanical Engineering, Villanova University, 800 Lancaster Avenue, Villanova, PA 19085
| |
Collapse
|
3
|
Blouin S, Misof BM, Mähr M, Fratzl-Zelman N, Roschger P, Lueger S, Messmer P, Keplinger P, Rauch F, Glorieux FH, Berzlanovich A, Gruber GM, Brugger PC, Shane E, Recker RR, Zwerina J, Hartmann MA. Osteocyte lacunae in transiliac bone biopsy samples across life span. Acta Biomater 2023; 157:275-287. [PMID: 36549635 DOI: 10.1016/j.actbio.2022.11.051] [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: 08/01/2022] [Revised: 11/23/2022] [Accepted: 11/24/2022] [Indexed: 12/23/2022]
Abstract
Osteocytes act as bone mechanosensors, regulators of osteoblast/osteoclast activity and mineral homeostasis, however, knowledge about their functional/morphological changes throughout life is limited. We used quantitative backscattered electron imaging (qBEI) to investigate osteocyte lacunae sections (OLS) as a 2D-surrogate characterizing the osteocytes. OLS characteristics, the density of mineralized osteocyte lacunae (i.e., micropetrotic osteocytes, md.OLS-Density in nb/mm2) and the average degree of mineralization (CaMean in weight% calcium) of cortex and spongiosa were analyzed in transiliac biopsy samples from healthy individuals under 30 (n=59) and over 30 years (n=50) (i.e., before and after the age of peak bone mass, respectively). We found several differences in OLS-characteristics: 1). Inter-individually between the age groups: OLS-Density and OLS-Porosity were reduced by about 20% in older individuals in spongiosa and in cortex versus younger probands (both, p < 0.001). 2). Intra-individually between bone compartments: OLS-Density was higher in the cortex, +18.4%, p < 0.001 for younger and +7.6%, p < 0.05 for older individuals. Strikingly, the most frequent OLS nearest-neighbor distance was about 30 µm in both age groups and at both bone sites revealing a preferential organization of osteocytes in clusters. OLS-Density was negatively correlated with CaMean in both spongiosa and cortex (both, p < 0.001). Few mineralized OLS were found in young individuals along with an increase of md.OLS-Density with age. In summary, this transiliac bone sample analysis of 200000 OLS from 109 healthy individuals throughout lifespan reveals several age-related differences in OLS characteristics. Moreover, our study provides reference data from healthy individuals for different ages to be used for diagnosis of bone abnormalities in diseases. STATEMENT OF SIGNIFICANCE: Osteocytes are bone cells embedded in lacunae within the mineralized bone matrix and have a key role in the bone metabolism and the mineral homeostasis. Not easily accessible, we used quantitative backscattered electron imaging to determine precisely number and shape descriptors of the osteocyte lacunae in 2D. We analyzed transiliac biopsy samples from 109 individuals with age distributed from 2 to 95 years. Compact cortical bone showed constantly higher lacunar density than cancellous bone but the lacunar density in both bone tissue decreased with age before the peak bone mass age at 30 years and stabilized or even increased after this age. This extensive study provides osteocyte lacunae reference data from healthy individuals usable for bone pathology diagnosis.
Collapse
Affiliation(s)
- Stéphane Blouin
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department Hanusch Hospital, Vienna, Austria & Vienna Bone and Growth Center, Vienna, Austria.
| | - Barbara M Misof
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department Hanusch Hospital, Vienna, Austria & Vienna Bone and Growth Center, Vienna, Austria
| | - Matthias Mähr
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department Hanusch Hospital, Vienna, Austria & Vienna Bone and Growth Center, Vienna, Austria
| | - Nadja Fratzl-Zelman
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department Hanusch Hospital, Vienna, Austria & Vienna Bone and Growth Center, Vienna, Austria
| | - Paul Roschger
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department Hanusch Hospital, Vienna, Austria & Vienna Bone and Growth Center, Vienna, Austria
| | - Sonja Lueger
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department Hanusch Hospital, Vienna, Austria & Vienna Bone and Growth Center, Vienna, Austria
| | - Phaedra Messmer
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department Hanusch Hospital, Vienna, Austria & Vienna Bone and Growth Center, Vienna, Austria
| | - Petra Keplinger
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department Hanusch Hospital, Vienna, Austria & Vienna Bone and Growth Center, Vienna, Austria
| | - Frank Rauch
- Shriners Hospital for Children and McGill University, Montreal, ON QC, H4A 0A9, Canada
| | - Francis H Glorieux
- Shriners Hospital for Children and McGill University, Montreal, ON QC, H4A 0A9, Canada
| | - Andrea Berzlanovich
- Unit of Forensic Gerontology, Center of Forensic Medicine, Medical University of Vienna, Vienna, Austria
| | - Gerlinde M Gruber
- Department of Anatomy and Biomechanics, Karl Landsteiner University of Health Sciences, Krems, Austria
| | - Peter C Brugger
- Center for Anatomy and Cell Biology, Department of Anatomy, Medical University of Vienna, Vienna, Austria
| | - Elizabeth Shane
- Department of Medicine, Division of Endocrinology, Columbia University College of Physicians and Surgeons, New York, NY, USA
| | - Robert R Recker
- Osteoporosis Research Center, Creighton University, Omaha, Nebraska, USA
| | - Jochen Zwerina
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department Hanusch Hospital, Vienna, Austria & Vienna Bone and Growth Center, Vienna, Austria
| | - Markus A Hartmann
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department Hanusch Hospital, Vienna, Austria & Vienna Bone and Growth Center, Vienna, Austria
| |
Collapse
|
4
|
Валеева ДИ, Тюрин АВ. ИССЛЕДОВАНИЕ СОСТОЯНИЯ КОСТНОЙ ТКАНИ У ЛИЦ С НЕСОВЕРШЕННЫМ ОСТЕОГЕНЕЗОМ МОЛОДОГО ВОЗРАСТА. OSTEOPOROSIS AND BONE DISEASES 2023. [DOI: 10.14341/osteo12992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Д. И. Валеева
- ФГБОУ ВО Башкирский государственный медицинский университет
| | - А. В. Тюрин
- ФГБОУ ВО Башкирский государственный медицинский университет
| |
Collapse
|
5
|
Qian W, Schmidt R, Turner JA, Bare SP, Lappe JM, Recker RR, Akhter MP. A pilot study on the nanoscale properties of bone tissue near lacunae in fracturing women. Bone Rep 2022; 17:101604. [PMID: 35874169 PMCID: PMC9304727 DOI: 10.1016/j.bonr.2022.101604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 07/09/2022] [Accepted: 07/12/2022] [Indexed: 11/17/2022] Open
Abstract
The goal of this study is to investigate the causes of osteoporosis-related skeletal fragility in postmenopausal women. We hypothesize that bone fragility in these individuals is largely due to mineral, and/or intrinsic material properties in the osteocyte lacunar/peri-lacunar regions of bone tissue. Innovative measurements with nanoscale resolution, including scanning electron microscope (SEM), an atomic force microscope that is integrated with infrared spectroscopy (AFM-IR), and nanoindentation, were used to characterize osteocyte lacunar and peri-lacunar properties in bone biopsies from fracturing (Cases) and matched (Age, BMD), non-fracturing (Controls) postmenopausal healthy women. In the peri-lacunar space, the nanoindentation results show that the modulus and hardness of the Controls are lower than the Cases. The AFM-IR results conclusively show that the mineral matrix, maturity (peak) (except in outer/far regions in Controls) were greater in Controls than in Cases. Furthermore, these results indicate that while mineral-to-matrix area ratio tend to be greater, the mineral maturity and crystallinity peak ratio “near” lacunae is greater than at regions “far” or more distance from lacunae in the Controls only. Due to the heterogeneity of bone structure, additional measurements are needed to provide more convincing evidence of altered lacunar characteristics and changes in the peri-lacunar bone as mechanisms related to postmenopausal women and fragility. Such findings would motivate new osteocyte-targeted treatments to reduce fragility fracture risks in these groups. Material properties around the osteocyte lacunae in human bone biopsies are presented. Using nanoindentation/nanoIR, the properties in bone tissue from women are measured. Mineral and material strength are different between fracturing and non-fracturing women.
Collapse
Affiliation(s)
- Wen Qian
- Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588-0526, United States of America
| | - Roman Schmidt
- Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588-0526, United States of America
| | - Joseph A. Turner
- Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588-0526, United States of America
| | - Sue P. Bare
- Osteoporosis Research Center, Creighton University School of Medicine, Omaha, NE 68178, United States of America
| | - Joan M. Lappe
- Osteoporosis Research Center, Creighton University School of Medicine, Omaha, NE 68178, United States of America
| | - Robert R. Recker
- Osteoporosis Research Center, Creighton University School of Medicine, Omaha, NE 68178, United States of America
| | - Mohammed P. Akhter
- Osteoporosis Research Center, Creighton University School of Medicine, Omaha, NE 68178, United States of America
- Corresponding author.
| |
Collapse
|
6
|
Kadri A, Binkley N, Daffner SD, Anderson PA. Clinical risk factor status in patients with vertebral fracture but normal bone mineral density. Spine J 2022; 22:1634-1641. [PMID: 35680015 DOI: 10.1016/j.spinee.2022.05.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 04/26/2022] [Accepted: 05/26/2022] [Indexed: 02/03/2023]
Abstract
BACKGROUND CONTEXT Normal bone mineral density (BMD) as measured by dual-energy x-ray absorptiometry (DXA) is present in approximately 10% of older adults with fracture. BMD alone does not evaluate bone quality or clinical risk factors, and therefore, may not adequately capture a patient's fracture risk. Thus, despite a normal DXA-measured BMD, the underlying bone may be abnormal, suggesting that further bone health evaluation, and potentially, pharmacologic treatment may be warranted. PURPOSE To determine the prevalence of normal BMD, clinical fracture risk factors, and quantitative risk of fracture using the Fracture Risk Assessment Tool (FRAX) in vertebral fracture patients with normal BMD enrolled in the Own the Bone registry, thus facilitating identification of those who meet criteria for anti-osteoporosis therapy. STUDY DESIGN/SETTING Retrospective, national registry-based cohort. PATIENT SAMPLE From July 2016 to July 2021, 1,807 patients age ≥50 who sustained a vertebral fracture and had DXA data available from within 2 years prior to enrollment in the American Orthopaedic Association's Own the Bone (AOA OTB) registry were included. OUTCOME MEASURES World Health Organization (WHO) DXA T-score based bone classification criteria; FRAX risk scores of major osteoporotic fracture or hip fracture. METHODS Demographic data, prior fracture site, and clinical fracture risk factors were collected. BMD status was classified by the WHO T-score criteria: ≥ -1.0 normal, -1.1 to -2.4 osteopenia, and ≤ -2.5 osteoporosis, with low bone mass including either osteopenia or osteoporosis. In normal BMD patients, FRAX scores were calculated with and without BMD, with the treatment threshold defined as a major osteoporotic fracture risk ≥20% or hip fracture risk ≥3%. RESULTS Mean±SD age was 72.0±9.7, 78.1% were female, and 92.4% were Caucasian. Normal BMD was present in 7.9%. Clinical fracture risk factors including alcohol use ≥3 units/day and history of ≥2 falls in the year prior to enrollment were more common in normal BMD (11.2% and 28%, respectively) compared to low bone mass patients (3.4% and 25.2%, respectively). A prior vertebral fracture had occurred in 49.5% with normal BMD compared to 45.8% with low bone mass, while a prior non-major osteoporotic fracture occurred in 28.9% and 29.3% of normal BMD and low bone mass patients, respectively. In normal BMD patients, either a prior fracture or FRAX risk with BMD meeting treatment thresholds was present in 85%. CONCLUSIONS Clear indications for receipt of pharmacologic therapy, ie, prior fracture or elevated fracture risk, were present in most patients with vertebral fracture and normal BMD enrolled in the AOA OTB. Prior non-major osteoporotic fractures were common and may be useful indicators of underlying bone disease. Surgeons must recognize that other important risk factors apart from BMD may indicate poor bone health, and thus, help guide further bone health evaluation.
Collapse
Affiliation(s)
- Aamir Kadri
- Department of Orthopedics & Rehabilitation, UW Medical Foundation Centennial Building, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Neil Binkley
- Osteoporosis Clinical Research Program,University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Scott D Daffner
- Department of Orthopaedics,West Virginia University School of Medicine, Morgantown, WV, USA
| | - Paul A Anderson
- Department of Orthopedics & Rehabilitation, UW Medical Foundation Centennial Building, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
| |
Collapse
|
7
|
The Spatial Distribution of Cellular Voids in the Human Otic Capsule: An Unbiased Quantification of Osteocyte-Depleted Areas. Otol Neurotol 2022; 43:e804-e809. [PMID: 35941668 DOI: 10.1097/mao.0000000000003626] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE This study aimed to describe the spatial distribution of osteocyte-depleted areas, so-called cellular voids, in the human otic capsule and compare it with that of otosclerosis. BACKGROUND Systematic histological studies of the bony otic capsule have revealed an osteoprotegerin (OPG)-mediated inhibition of normal bone remodeling around the inner ear. The resulting accumulation of bony degeneration and dead osteocytes has been thoroughly documented, and the spatial distribution of dead osteocytes and matrix microcracks resembles that of the human ear disease otosclerosis. Clusters of dead osteocytes that may interfere with osteocyte connectivity and thereby the OPG signaling pathway have been described in human temporal bones. It is possible that these cellular voids create disruptions in the antiresorptive OPG signal that may give rise to local pathological remodeling. METHODS Recently, a method of detecting cellular voids was developed. This study uses unbiased stereology to document the spatial distribution of cellular voids in bulk-stained undecalcified human temporal bone. RESULTS Cellular voids accumulate around the inner ear and increase in number and size with age. Furthermore, cellular voids are more frequently found in the anterior and lateral regions of the otic capsule, which are known predilection sites of otosclerosis. CONCLUSION This colocalization of cellular voids and otosclerosis suggests a causal relationship between focal degeneration and otosclerotic remodeling.
Collapse
|
8
|
Quantifying how altered lacunar morphology and perilacunar tissue properties influence local mechanical environment of osteocyte lacunae using finite element modeling. J Mech Behav Biomed Mater 2022; 135:105433. [DOI: 10.1016/j.jmbbm.2022.105433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 08/09/2022] [Accepted: 08/26/2022] [Indexed: 11/23/2022]
|
9
|
Ledoux C, Boaretti D, Sachan A, Müller R, Collins CJ. Clinical Data for Parametrization of In Silico Bone Models Incorporating Cell-Cytokine Dynamics: A Systematic Review of Literature. Front Bioeng Biotechnol 2022; 10:901720. [PMID: 35910035 PMCID: PMC9335409 DOI: 10.3389/fbioe.2022.901720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 06/13/2022] [Indexed: 11/13/2022] Open
Abstract
In silico simulations aim to provide fast, inexpensive, and ethical alternatives to years of costly experimentation on animals and humans for studying bone remodeling, its deregulation during osteoporosis and the effect of therapeutics. Within the varied spectrum of in silico modeling techniques, bone cell population dynamics and agent-based multiphysics simulations have recently emerged as useful tools to simulate the effect of specific signaling pathways. In these models, parameters for cell and cytokine behavior are set based on experimental values found in literature; however, their use is currently limited by the lack of clinical in vivo data on cell numbers and their behavior as well as cytokine concentrations, diffusion, decay and reaction rates. Further, the settings used for these parameters vary across research groups, prohibiting effective cross-comparisons. This review summarizes and evaluates the clinical trial literature that can serve as input or validation for in silico models of bone remodeling incorporating cells and cytokine dynamics in post-menopausal women in treatment, and control scenarios. The GRADE system was used to determine the level of confidence in the reported data, and areas lacking in reported measures such as binding site occupancy, reaction rates and cell proliferation, differentiation and apoptosis rates were highlighted as targets for further research. We propose a consensus for the range of values that can be used for the cell and cytokine settings related to the RANKL-RANK-OPG, TGF-β and sclerostin pathways and a Levels of Evidence-based method to estimate parameters missing from clinical trial literature.
Collapse
Affiliation(s)
- Charles Ledoux
- Institute for Biomechanics, ETH Zurich, Zurich, Switzerland
| | | | - Akanksha Sachan
- Institute for Biomechanics, ETH Zurich, Zurich, Switzerland
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai, India
| | - Ralph Müller
- Institute for Biomechanics, ETH Zurich, Zurich, Switzerland
| | - Caitlyn J. Collins
- Institute for Biomechanics, ETH Zurich, Zurich, Switzerland
- Department for Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VI,United States
- *Correspondence: Caitlyn J. Collins,
| |
Collapse
|
10
|
Goff E, Cohen A, Shane E, Recker RR, Kuhn G, Müller R. Large-scale osteocyte lacunar morphological analysis of transiliac bone in normal and osteoporotic premenopausal women. Bone 2022; 160:116424. [PMID: 35460961 DOI: 10.1016/j.bone.2022.116424] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 04/13/2022] [Accepted: 04/14/2022] [Indexed: 11/29/2022]
Abstract
Bone's ability to adapt is governed by the network of embedded osteocytes, which inhabit individual pores called lacunae. The morphology of these lacunae and their resident osteocytes are known to change with age and diseases such as postmenopausal osteoporosis. However, it is unclear whether alterations in lacunar morphology are present in younger populations with osteoporosis. To investigate this, we implemented a previously validated methodology to image and quantify the three-dimensional morphometries of lacunae on a large scale with ultra-high-resolution micro-computed tomography (microCT) in transiliac bone biopsies from three groups of premenopausal women: control n = 39; idiopathic osteoporosis (IOP) n = 45; idiopathic low BMD (ILBMD) n = 19. Lacunar morphometric parameters were measured in both trabecular and cortical bone such as lacunar density (Lc.N/BV), lacunar volume (Lc.V), and lacunar sphericity (Lc.Sr). These were then compared against each other and also with previously measured tissue morphometries such as bone volume density (BV/TV), trabecular separation (Tb.Sp), trabecular number (Tb.N), and others. We detected no differences in lacunar morphology between the IOP, ILBMD and healthy premenopausal women. In contrast, we did find significant differences between lacunar morphologies including Lc.N/BV, Lc. V, and Lc. Sr in cortical and trabecular regions within all three groups (p < 0.001), which was consistent with our previous findings on a subgroup of the healthy group. Furthermore, we discovered strong correlations between Lc. Sr from trabecular regions with the measured BV/TV (R = -0.90, p < 0.05). The findings and comprehensive lacunar dataset we present here will be a crucial foundation for future investigations of the relationship between osteocyte lacunar morphology and disease.
Collapse
Affiliation(s)
- Elliott Goff
- Institute for Biomechanics, ETH Zurich, Zurich, Switzerland
| | - Adi Cohen
- Department of Medicine, Columbia University Vagelos College of Physicians & Surgeons, New York, NY, USA
| | - Elizabeth Shane
- Department of Medicine, Columbia University Vagelos College of Physicians & Surgeons, New York, NY, USA
| | - Robert R Recker
- Department of Medicine, Creighton University Medical Center, Omaha, NE, USA
| | - Gisela Kuhn
- Institute for Biomechanics, ETH Zurich, Zurich, Switzerland
| | - Ralph Müller
- Institute for Biomechanics, ETH Zurich, Zurich, Switzerland.
| |
Collapse
|
11
|
Gorter EA, Reinders CR, Krijnen P, Appelman-Dijkstra NM, Schipper IB. Serum sclerostin levels in osteoporotic fracture patients. Eur J Trauma Emerg Surg 2022; 48:4857-4865. [PMID: 35705746 DOI: 10.1007/s00068-022-02017-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 05/23/2022] [Indexed: 12/23/2022]
Abstract
PURPOSE Sclerostin inhibits bone formation and stimulates bone resorption. Previous studies found a positive association between bone density and serum sclerostin, but literature on sclerostin levels in osteoporotic fracture patients is scarce. The aim of the present study was to compare the serum sclerostin levels in osteoporotic and non-osteoporotic fracture patients and to assess the correlation of the sclerostin levels with bone mineral density and vitamin D status. METHODS In this cross-sectional study, we included patients over 50 years, with an extremity fracture after low-energy trauma treated between 2012 and 2018, with biobank samples and available bone density measurements by Dual X-ray Absorption. Osteoporosis was diagnosed according the World Health Organisation criteria. Vitamin D deficiency was defined as a 25(OH)D concentration < 30 nmol/L. After defrosting biobank samples, serum sclerostin was measured using the human SOST (sclerostin) enzyme-linked immunosorbent assay kit. We prespecified a subgroup analysis including only female patients. RESULTS 179 patients were included of whom 139(78%) were female. In 46 patients (25.7%), osteoporosis was diagnosed. Bone mineral density was positively associated with sclerostin levels (r = 0.17, p = 0.026) and patients with osteoporosis had a significantly lower serum sclerostin compared to non-osteoporotic fracture patients (mean 41.9 pmol/L vs 48.1 pmol/L; p = 0.03). This difference remained significant after correction for potential confounders. Similar results were found in the subgroup of female patients. No association between serum sclerostin and vitamin D deficiency was found. CONCLUSION Osteoporotic fracture patients had lower levels of sclerostin than non-osteoporotic fracture patients. Future research should focus on the use of sclerostin as biomarker for osteoporosis in fracture patients.
Collapse
Affiliation(s)
- Erwin A Gorter
- Departments of Trauma Surgery, Leiden University Medical Center, postzone K6-R, P.O. Box 9600, 2300 RC, Leiden, The Netherlands.
| | - Casper R Reinders
- Departments of Trauma Surgery, Leiden University Medical Center, postzone K6-R, P.O. Box 9600, 2300 RC, Leiden, The Netherlands
| | - Pieta Krijnen
- Departments of Trauma Surgery, Leiden University Medical Center, postzone K6-R, P.O. Box 9600, 2300 RC, Leiden, The Netherlands
| | | | - Inger B Schipper
- Departments of Trauma Surgery, Leiden University Medical Center, postzone K6-R, P.O. Box 9600, 2300 RC, Leiden, The Netherlands
| |
Collapse
|
12
|
Allison H, O'Sullivan L, McNamara L. Temporal changes in cortical microporosity during estrogen deficiency associated with perilacunar resorption and osteocyte apoptosis: A pilot study. Bone Rep 2022; 16:101590. [PMID: 35663377 PMCID: PMC9156983 DOI: 10.1016/j.bonr.2022.101590] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 05/13/2022] [Accepted: 05/14/2022] [Indexed: 02/07/2023] Open
Abstract
Osteocytes can actively regulate bone microporosity, through either perilacunar resorption or micropetrosis following apoptosis. Osteocyte apoptosis is more prevalent in estrogen deficiency and changes in the lacunar-canalicular network of osteocytes have been reported. Temporal changes in bone mineralisation and osteocytes cellular strains occur, which might be associated with osteocyte-driven microporosity changes, although time dependant changes in bone microporosity are not yet fully understood. In this pilot study we conducted micro-CT analysis, backscatter electron imaging and histological analysis of femoral cortical bone form an ovariectomized rat model of osteoporosis to investigate whether estrogen deficiency causes temporal changes in lacunar and vascular porosity. We also assessed MMP14 expression, lacunar occupancy and mineral infilling, as indicators of perilacunar resorption and micropetrosis. We report temporal changes in cortical microporosity in estrogen deficiency. Specifically, canalicular and vascular porosity initially increased (4 weeks post-OVX), coinciding with the period of rapid bone loss, whereas in the longer term (14 weeks post-OVX) lacunar and canalicular diameter decreased. Interestingly, these changes coincided with an increased prevalence of empty lacunae and osteocyte lacunae were observed to be more circular with a mineralised border around the lacunar space. In addition we report an increase in MMP14+ osteocytes, which also suggests active matrix degradation by these cells. Together these results provide an insight into the temporal changes in cortical microporosity during estrogen deficiency and suggest the likelihood of occurrence of both perilacunar resorption and osteocyte apoptosis leading to micropetrosis. We propose that microporosity changes arise due to processes driven by distinct populations of osteocytes, which are either actively resorbing their matrix or have undergone apoptosis and are infilling lacunae by micropetrosis.
Collapse
Key Words
- BMDD, Bone mineral density distribution
- BSEM
- BSEM, Backscattered scanning electron microscopy
- BV, Bone volume
- Dm, Diameter
- Estrogen deficiency
- Lacunar
- Lc, Lacunar
- MMP, Matrix metalloproteases
- Micro-CT, Micro computed tomography
- Microporosity
- OVX, Ovariectomized
- PLR, Perilacunar resorption
- Sp, spacing
- TRAP, Tartrate-resistant acid phosphatase
- TV, Total volume
- Tb, Trabecular
- Th, Thickness
- V Ca, Vascular canal
- Vascular canals
- micro-CT
- με, Microstrain (ε ×10−6)
Collapse
Affiliation(s)
- H. Allison
- Mechanobiology and Medical Devices Research Group (MMDRG), Centre for Biomechanics Research (BioMEC), Biomedical Engineering, College of Science and Engineering, National University of Ireland Galway, Ireland
| | - L.M. O'Sullivan
- Mechanobiology and Medical Devices Research Group (MMDRG), Centre for Biomechanics Research (BioMEC), Biomedical Engineering, College of Science and Engineering, National University of Ireland Galway, Ireland
| | - L.M. McNamara
- Mechanobiology and Medical Devices Research Group (MMDRG), Centre for Biomechanics Research (BioMEC), Biomedical Engineering, College of Science and Engineering, National University of Ireland Galway, Ireland
| |
Collapse
|
13
|
Sang W, Li Y, Guignon J, Liu XS, Ural A. Structural role of osteocyte lacunae on mechanical properties of bone matrix: A cohesive finite element study. J Mech Behav Biomed Mater 2022; 125:104943. [PMID: 34736032 PMCID: PMC8670554 DOI: 10.1016/j.jmbbm.2021.104943] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 09/05/2021] [Accepted: 10/26/2021] [Indexed: 01/03/2023]
Abstract
Despite the extensive studies on biological function of osteocytes, there are limited studies that evaluated the structural role of osteocyte lacunae on local mechanical properties of the bone matrix. As a result, the goal of this study was to elucidate the independent contribution of osteocyte lacunae structure on mechanical properties and fracture behavior of the bone matrix uncoupled from its biological effects and bone tissue composition variation. This study combined cohesive finite element modeling with experimental data from a lactation rat model to evaluate the influence of osteocyte lacunar area porosity, density, size, axis ratio, and orientation on the elastic modulus, ultimate strength, and ultimate strain of the bone matrix as well as on local crack formation and propagation. It also performed a parametric study to isolate the influence of a single osteocyte lacunae structural property on the mechanical properties of the bone matrix. The experimental measurements demonstrated statistically significant differences in lacunar size between ovariectomized rats with lactation history and virgin groups (both ovariectomized and intact) and in axis ratio between rats with lactation history and virgins. There were no differences in mechanical properties between virgin and lactation groups as determined by the finite element simulations. However, there were statistically significant linear relationships between the physiological range of osteocyte lacunar area porosity, density, size, and orientation and the elastic modulus and ultimate strength of the bone matrix in virgin and lactation rats. The parametric study also revealed similar but stronger relationships between elastic modulus and ultimate strength and lacunar density, size, and orientation. The simulations also demonstrated that the osteocyte lacunae guided the crack propagation through local stress concentrations. In summary, this study enhanced the limited knowledge on the structural role of osteocyte lacunae on local mechanical properties of the bone matrix. These data are important in gaining a better understanding of the mechanical implications of the local modifications due to osteocytes in the bone matrix.
Collapse
Affiliation(s)
- Wen Sang
- Department of Mechanical Engineering, Villanova University, 800 Lancaster Avenue, Villanova, PA, USA
| | - Yihan Li
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, 332A Stemmler Hall, 36th Street and Hamilton Walk, Philadelphia, PA, USA
| | - Jane Guignon
- Department of Mechanical Engineering, Villanova University, 800 Lancaster Avenue, Villanova, PA, USA
| | - X Sherry Liu
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, 332A Stemmler Hall, 36th Street and Hamilton Walk, Philadelphia, PA, USA
| | - Ani Ural
- Department of Mechanical Engineering, Villanova University, 800 Lancaster Avenue, Villanova, PA, USA.
| |
Collapse
|
14
|
Yajima A, Tsuchiya K, Burr DB, Murata T, Nakamura M, Inaba M, Tominaga Y, Tanizawa T, Nakayama T, Ito A, Nitta K. Micropetrosis in hemodialysis patients. Bone Rep 2021; 15:101150. [PMID: 34926729 PMCID: PMC8649646 DOI: 10.1016/j.bonr.2021.101150] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 11/06/2021] [Accepted: 11/15/2021] [Indexed: 01/03/2023] Open
Abstract
Micropetrosis develops as a result of stagnation of calcium, phosphorus and bone fluid, which appears as highly mineralized bone area in the osteocytic perilacunar/canalicular system regardless of bone turnover of the patients. And microcracks are predisposed to increase in these areas, which leads to increased bone fragility. However, micropetrosis of hemodialysis (HD) patients has not been discussed at all. Micropetrosis area per bone area (Mp.Ar/B·Ar) and osteocyte number per micropetrosis area (Ot.N/Mp.Ar) were measured in nine HD patients with renal hyperparathyroidism (Group I), twelve patients with hypoparathyroidism within 1 year after the treatment of renal hyperparathyroidism (Group II) and seven patients suffering from hypoparathyroidism for over two years (Group III). And bone mineral density (BMD) and tissue mineral density (TMD) were calculated using μCT to evaluate bone mineral content of iliac bone of the patients. These parameters were compared among the three groups. Only Mp.Ar/B·Ar was statistically greater in Group II and III compared to Group I in the parameters of bone mineral content and micropetrosis. However, the other parameters were not statistically different among the three groups. In long-term HD patients, BMD and TMD may be modified by the causes of renal insufficiency and the treatment of renal bone disease. We concluded that Mp.Ar/B·Ar was greater in patients with long-term hypoparathyroidism than both those with short-term hypoparathyroidism and with renal hyperparathyroidism. Special attention should be paid to avoid long-term hypoparathyroidism of the patients from the view point of increased fracture risk caused by increased micropetrosis area.
Collapse
Affiliation(s)
- Aiji Yajima
- Department of Anatomy, Cell Biology and Physiology, Indiana University, School of Medicine, Indianapolis, IN, USA.,Department of Urology, Tokyo Teishin Hospital, Tokyo, Japan.,Department of Blood Purification, Kidney Center, Tokyo Women's Medical University, Tokyo, Japan
| | - Ken Tsuchiya
- Department of Blood Purification, Kidney Center, Tokyo Women's Medical University, Tokyo, Japan
| | - David B Burr
- Department of Anatomy, Cell Biology and Physiology, Indiana University, School of Medicine, Indianapolis, IN, USA
| | - Taro Murata
- Department of Urology, Tokyo Teishin Hospital, Tokyo, Japan
| | - Masaki Nakamura
- Department of Nephrology and Urology, NTT East Kanto Hospital, Tokyo, Japan
| | - Masaaki Inaba
- Department of Metabolism, Endocrinology and Molecular Medicine, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Yoshihiro Tominaga
- Department of Endocrine Surgery, Nagoya Daini Red Cross Hospital, Nagoya, Japan
| | | | | | - Akemi Ito
- Ito Bone Histomorphometry Institute, Niigata, Japan
| | - Kosaku Nitta
- Department of Medicine, Kidney Center, Tokyo Women's Medical University, Tokyo, Japan
| |
Collapse
|
15
|
Casanova M, Schindeler A, Peacock L, Lee L, Schneider P, Little DG, Müller R. Characterization of the Developing Lacunocanalicular Network During Fracture Repair. JBMR Plus 2021; 5:e10525. [PMID: 34532613 PMCID: PMC8441443 DOI: 10.1002/jbm4.10525] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 05/23/2021] [Accepted: 06/06/2021] [Indexed: 11/09/2022] Open
Abstract
Fracture repair is a normal physiological response to bone injury. During the process of bony callus formation, a lacunocanalicular network (LCN) is formed de novo that evolves with callus remodeling. Our aim was the longitudinal assessment of the development and evolution of the LCN during fracture repair. To this end, 45 adult wild‐type C57BL/6 mice underwent closed tibial fracture surgery. Fractured and intact contralateral tibias were harvested after 2, 3, and 6 weeks of bone healing (n = 15/group). High‐resolution micro–computed tomography (μCT) and deconvolution microscopy (DV) approaches were applied to quantify lacunar number density from the calluses and intact bone. On histological sections, Goldner's trichrome staining was used to assess lacunar occupancy, fluorescein isothiocyanate staining to visualize the canalicular network, and terminal deoxynucleotidyl transferase–mediated deoxyuridine triphosphate‐biotin nick end labeling (TUNEL) staining to examine osteocyte apoptosis. Analysis of μCT scans showed progressive decreases in mean lacuna volume over time (−27% 2–3 weeks; −13% 3–6 weeks). Lacunar number density increased considerably between 2 and 3 weeks (+156%). Correlation analysis was performed, showing a positive linear relationship between canalicular number density and trabecular thickness (R2 = 0.56, p < 0.001) and an inverse relationship between mean lacuna volume and trabecular thickness (R2 = 0.57, p < 0.001). Histology showed increases in canalicular number density over time (+22% 2–3 weeks, +51% 3–6 weeks). Lacunar occupancy in new bone of the callus was high (>90%), but the old cortical bone within the fracture site appeared necrotic as it underwent resorption. In conclusion, our data shows a progressive increase in the complexity of the LCN over time during fracture healing and demonstrates that this network is initiated during the early stages of repair. Further studies are needed to address the functional importance of osteocytes in bone healing, particularly in detecting and translating the effects of micromotion in the fracture. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.
Collapse
Affiliation(s)
| | - Aaron Schindeler
- Orthopaedic Research & Biotechnology The Children's Hospital at Westmead Westmead Australia.,Discipline of Child and Adolescent Health University of Sydney Camperdown Australia
| | - Lauren Peacock
- Orthopaedic Research & Biotechnology The Children's Hospital at Westmead Westmead Australia
| | - Lucinda Lee
- Orthopaedic Research & Biotechnology The Children's Hospital at Westmead Westmead Australia.,Discipline of Child and Adolescent Health University of Sydney Camperdown Australia
| | - Philipp Schneider
- Institute for Biomechanics ETH Zurich Zurich Switzerland.,Bioengineering Science Research Group, Faculty of Engineering and Physical Sciences University of Southampton Southampton UK.,High-Performance Vision Systems, Center for Vision, Automation & Control Austrian Institute of Technology (AIT) Vienna Austria
| | - David G Little
- Orthopaedic Research & Biotechnology The Children's Hospital at Westmead Westmead Australia.,Discipline of Child and Adolescent Health University of Sydney Camperdown Australia
| | - Ralph Müller
- Institute for Biomechanics ETH Zurich Zurich Switzerland
| |
Collapse
|
16
|
Shipov A, Zaslansky P, Riesemeier H, Segev G, Atkins A, Kalish-Achrai N, Weiner S, Shahar R. The influence of estrogen deficiency on the structural and mechanical properties of rat cortical bone. PeerJ 2021; 9:e10213. [PMID: 33520431 PMCID: PMC7811283 DOI: 10.7717/peerj.10213] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 09/28/2020] [Indexed: 11/20/2022] Open
Abstract
Background Post-menopausal osteoporosis is a common health problem worldwide, most commonly caused by estrogen deficiency. Most of the information regarding the skeletal effects of this disease relates to trabecular bone, while cortical bone is less studied. The purpose of this study was to evaluate the influence of estrogen deficiency on the structure and mechanical properties of cortical bone. Methods Eight ovariectomized (OVH) and eight intact (control) Sprague Dawley rats were used.Structural features of femoral cortical bone were studied by light microscopy, scanning electron microscopy and synchrotron-based microcomputer-tomography and their mechanical properties determined by nano-indentation. Results Cortical bone of both study groups contains two distinct regions: organized circumferential lamellae and disordered bone with highly mineralized cartilaginous islands. Lacunar volume was lower in the OVH group both in the lamellar and disorganized regions (182 ± 75 µm3 vs 232 ± 106 µm3, P < 0.001 and 195 ± 86 µm3 vs. 247 ± 106 µm3, P < 0.001, respectively). Lacunar density was also lower in both bone regions of the OVH group (40 ± 18 ×103 lacunae/mm3 vs. 47 ± 9×103 lacunae/mm3 in the lamellar region, P = 0.003 and 63 ± 18×103lacunae/mm3 vs. 75 ± 13×103 lacunae/mm3 in the disorganized region, P < 0.001). Vascular canal volume was lower in the disorganized region of the bone in the OVH group compared to the same region in the control group (P < 0.001). Indentation moduli were not different between the study groups in both bone regions. Discussion Changes to cortical bone associated with estrogen deficiency in rats require high-resolution methods for detection. Caution is required in the application of these results to humans due to major structural differences between human and rat bone.
Collapse
Affiliation(s)
- Anna Shipov
- Koret School of Veterinary Medicine, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Paul Zaslansky
- Department for Operative and Preventive Dentistry. Centrum für Zahn-, Mund- und Kieferheilkunde, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | | | - Gilad Segev
- Koret School of Veterinary Medicine, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Ayelet Atkins
- Department of Chemistry and Bar Ilan Institute of Nanotechnology and Advanced Materials (BINA), Bar-Ilan University, Ramat Gan, Israel
| | - Noga Kalish-Achrai
- Koret School of Veterinary Medicine, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Stephen Weiner
- Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Ron Shahar
- Koret School of Veterinary Medicine, The Hebrew University of Jerusalem, Rehovot, Israel
| |
Collapse
|
17
|
Eichholz KF, Woods I, Riffault M, Johnson GP, Corrigan M, Lowry MC, Shen N, Labour M, Wynne K, O'Driscoll L, Hoey DA. Human bone marrow stem/stromal cell osteogenesis is regulated via mechanically activated osteocyte-derived extracellular vesicles. Stem Cells Transl Med 2020; 9:1431-1447. [PMID: 32672416 PMCID: PMC7581449 DOI: 10.1002/sctm.19-0405] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 04/24/2020] [Accepted: 05/24/2020] [Indexed: 12/18/2022] Open
Abstract
Bone formation or regeneration requires the recruitment, proliferation, and osteogenic differentiation of stem/stromal progenitor cells. A potent stimulus driving this process is mechanical loading. Osteocytes are mechanosensitive cells that play fundamental roles in coordinating loading-induced bone formation via the secretion of paracrine factors. However, the exact mechanisms by which osteocytes relay mechanical signals to these progenitor cells are poorly understood. Therefore, this study aimed to demonstrate the potency of the mechanically stimulated osteocyte secretome in driving human bone marrow stem/stromal cell (hMSC) recruitment and differentiation, and characterize the secretome to identify potential factors regulating stem cell behavior and bone mechanobiology. We demonstrate that osteocytes subjected to fluid shear secrete a distinct collection of factors that significantly enhance hMSC recruitment and osteogenesis and demonstrate the key role of extracellular vesicles (EVs) in driving these effects. This demonstrates the pro-osteogenic potential of osteocyte-derived mechanically activated extracellular vesicles, which have great potential as a cell-free therapy to enhance bone regeneration and repair in diseases such as osteoporosis.
Collapse
Affiliation(s)
- Kian F. Eichholz
- Department of Mechanical, Aeronautical and Biomedical EngineeringMaterials and Surface Science Institute, University of LimerickLimerickIreland
- Trinity Centre for Biomedical EngineeringTrinity Biomedical Sciences Institute, Trinity College DublinDublin 2Ireland
- Department of Mechanical and Manufacturing EngineeringSchool of Engineering, Trinity College DublinDublin 2Ireland
| | - Ian Woods
- Trinity Centre for Biomedical EngineeringTrinity Biomedical Sciences Institute, Trinity College DublinDublin 2Ireland
- Department of Mechanical and Manufacturing EngineeringSchool of Engineering, Trinity College DublinDublin 2Ireland
| | - Mathieu Riffault
- Trinity Centre for Biomedical EngineeringTrinity Biomedical Sciences Institute, Trinity College DublinDublin 2Ireland
- Department of Mechanical and Manufacturing EngineeringSchool of Engineering, Trinity College DublinDublin 2Ireland
| | - Gillian P. Johnson
- Department of Mechanical, Aeronautical and Biomedical EngineeringMaterials and Surface Science Institute, University of LimerickLimerickIreland
- Trinity Centre for Biomedical EngineeringTrinity Biomedical Sciences Institute, Trinity College DublinDublin 2Ireland
- Department of Mechanical and Manufacturing EngineeringSchool of Engineering, Trinity College DublinDublin 2Ireland
| | - Michele Corrigan
- Department of Mechanical, Aeronautical and Biomedical EngineeringMaterials and Surface Science Institute, University of LimerickLimerickIreland
- Trinity Centre for Biomedical EngineeringTrinity Biomedical Sciences Institute, Trinity College DublinDublin 2Ireland
- Department of Mechanical and Manufacturing EngineeringSchool of Engineering, Trinity College DublinDublin 2Ireland
| | - Michelle C. Lowry
- School of Pharmacy and Pharmaceutical Sciences and Trinity Biomedical Sciences InstituteTrinity College DublinDublinIreland
| | - Nian Shen
- Trinity Centre for Biomedical EngineeringTrinity Biomedical Sciences Institute, Trinity College DublinDublin 2Ireland
- Department of Mechanical and Manufacturing EngineeringSchool of Engineering, Trinity College DublinDublin 2Ireland
| | - Marie‐Noelle Labour
- Department of Mechanical, Aeronautical and Biomedical EngineeringMaterials and Surface Science Institute, University of LimerickLimerickIreland
- Trinity Centre for Biomedical EngineeringTrinity Biomedical Sciences Institute, Trinity College DublinDublin 2Ireland
- Department of Mechanical and Manufacturing EngineeringSchool of Engineering, Trinity College DublinDublin 2Ireland
| | - Kieran Wynne
- UCD Conway Institute of Biomolecular and Biomedical ResearchUniversity College DublinDublin 4Ireland
- Mass Spectrometry ResourceUniversity College DublinDublin 4Ireland
| | - Lorraine O'Driscoll
- School of Pharmacy and Pharmaceutical Sciences and Trinity Biomedical Sciences InstituteTrinity College DublinDublinIreland
| | - David A. Hoey
- Department of Mechanical, Aeronautical and Biomedical EngineeringMaterials and Surface Science Institute, University of LimerickLimerickIreland
- Trinity Centre for Biomedical EngineeringTrinity Biomedical Sciences Institute, Trinity College DublinDublin 2Ireland
- Department of Mechanical and Manufacturing EngineeringSchool of Engineering, Trinity College DublinDublin 2Ireland
- Advanced Materials and Bioengineering Research CentreTrinity College Dublin & RCSIDublinIreland
| |
Collapse
|
18
|
Li X, Xu J, Dai B, Wang X, Guo Q, Qin L. Targeting autophagy in osteoporosis: From pathophysiology to potential therapy. Ageing Res Rev 2020; 62:101098. [PMID: 32535273 DOI: 10.1016/j.arr.2020.101098] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 05/26/2020] [Accepted: 06/03/2020] [Indexed: 12/19/2022]
Abstract
Osteoporosis is a highly prevalent disorder characterized by the loss of bone mass and microarchitecture deterioration of bone tissue, attributed to various factors, including menopause (primary), aging (primary) and adverse effects of relevant medications (secondary). In recent decades, knowledge regarding the etiological mechanisms underpinning osteoporosis emphasizes that bone cellular homeostasis, including the maintenance of cell functions, differentiation, and the response to stress, is tightly regulated by autophagy, which is a cell survival mechanism for eliminating and recycling damaged proteins and organelles. With the important roles in the maintenance of cellular homeostasis and organ function, autophagy has emerged as a potential target for the prevention and treatment of osteoporosis. In this review, we update and discuss the pathophysiology of autophagy in normal bone cell life cycle and metabolism. Then, the alternations of autophagy in primary and secondary osteoporosis, and the accompanied pathological process are discussed. Finally, we discuss current strategies, limitations, and challenges involved in targeting relevant pathways and propose strategies by which such hurdles may be circumvented in the future for their translation into clinical validations and applications for the prevention and treatment of osteoporosis.
Collapse
|
19
|
Rolvien T, Milovanovic P, Schmidt FN, von Kroge S, Wölfel EM, Krause M, Wulff B, Püschel K, Ritchie RO, Amling M, Busse B. Long-Term Immobilization in Elderly Females Causes a Specific Pattern of Cortical Bone and Osteocyte Deterioration Different From Postmenopausal Osteoporosis. J Bone Miner Res 2020; 35:1343-1351. [PMID: 31999373 DOI: 10.1002/jbmr.3970] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 12/23/2019] [Accepted: 01/19/2020] [Indexed: 12/11/2022]
Abstract
Immobilization as a result of long-term bed rest can lead to gradual bone loss. Because of their distribution throughout the bone matrix and remarkable interconnectivity, osteocytes represent the major mechanosensors in bone and translate mechanical into biochemical signals controlling bone remodeling. To test whether immobilization affects the characteristics of the osteocyte network in human cortical bone, femoral diaphyseal bone specimens were analyzed in immobilized female individuals and compared with age-matched postmenopausal individuals with primary osteoporosis. Premenopausal and postmenopausal healthy individuals served as control groups. Cortical porosity, osteocyte number and lacunar area, the frequency of hypermineralized lacunae, as well as cortical bone calcium content (CaMean) were assessed using bone histomorphometry and quantitative backscattered electron imaging (qBEI). Bone matrix properties were further analyzed by Fourier transform infrared spectroscopy (FTIR). In the immobilization group, cortical porosity was significantly higher, and qBEI revealed a trend toward higher matrix mineralization compared with osteoporotic individuals. Osteocyte density and canalicular density showed a declining rate from premenopausal toward healthy postmenopausal and osteoporotic individuals with peculiar reductions in the immobilization group, whereas the number of hypermineralized lacunae accumulated inversely. In conclusion, reduced osteocyte density and impaired connectivity during immobilization are associated with a specific bone loss pattern, reflecting a phenotype clearly distinguishable from postmenopausal osteoporosis. Immobilization periods may lead to a loss of survival signals for osteocytes, provoking bone loss that is even higher than in osteoporosis states, whereas osteocytic osteolysis remains absent. © 2020 The Authors. Journal of Bone and Mineral Research published by American Society for Bone and Mineral Research.
Collapse
Affiliation(s)
- Tim Rolvien
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Department of Orthopedics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Petar Milovanovic
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Laboratory for Anthropology and Skeletal Biology, Institute of Anatomy, Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Felix N Schmidt
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Simon von Kroge
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Eva M Wölfel
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Matthias Krause
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Department of Trauma, Hand, and Reconstructive Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Birgit Wulff
- Department of Forensic Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Klaus Püschel
- Department of Forensic Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Robert O Ritchie
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Michael Amling
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Björn Busse
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| |
Collapse
|
20
|
Zhang D, Li X, Pi C, Cai L, Liu Y, Du W, Yang W, Xie J. Osteoporosis-decreased extracellular matrix stiffness impairs connexin 43-mediated gap junction intercellular communication in osteocytes. Acta Biochim Biophys Sin (Shanghai) 2020; 52:517-526. [PMID: 32286624 DOI: 10.1093/abbs/gmaa025] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 12/20/2019] [Accepted: 02/24/2020] [Indexed: 02/05/2023] Open
Abstract
Osteocytes are the main sensitive and responsive cells for mechanical stimuli in bone. The connexin family enables them to communicate with each other via forming functional gap junctions. However, how osteoporosis-impaired extracellular mechanical property modulates gap junction intercellular communication in osteocytes remains elusive. In this study, we established an ovariectomy (OVX)-induced osteoporosis mouse model in vivo and a polydimethylsiloxane (PDMS)-based cell culture substrate model in vitro to explore the influence of extracellular matrix (ECM) stiffness on cell-to-cell communication in osteocytes. Firstly, we established an OVX-induced osteoporosis mouse model by characterizing the changes in radiography, morphology and histochemistry of femurs. Our results showed that osteoporosis decreased the bone matrix stiffness together with the changes including the loss of osteocytes and the decrease of protein markers. Meanwhile, the dendritic process interconnection and channel-forming protein, Cx43, were reduced in osteoporosis mice. Next we mimicked ECM stiffness changes in vitro by using PDMS substrates at ratios 1:5 for normal stiffness and 1:45 for osteoporosis stiffness. Our results showed that the decreased ECM stiffness reduced the number of dendritic processes in a single cell and gap junctions between adjacent osteocytes. We further detected the decreased expression of Cx43, in the substrate with decreased stiffness. Finally, we found that gap junction-based intercellular communication was reduced in living osteocytes in the substrate with decreased stiffness. This study demonstrates the correlation between ECM mechanical property and cell-to-cell communication in osteocytes and might pave the way for further exploration of osteoporosis in terms of biomechanics.
Collapse
Affiliation(s)
- Demao Zhang
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610064, China
| | - Xin Li
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610064, China
| | - Caixia Pi
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610064, China
| | - Linyi Cai
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610064, China
| | - Yang Liu
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610064, China
| | - Wei Du
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610064, China
| | - Wenbin Yang
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610064, China
- National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610064, China
| | - Jing Xie
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610064, China
| |
Collapse
|
21
|
Milovanovic P, Busse B. Phenomenon of osteocyte lacunar mineralization: indicator of former osteocyte death and a novel marker of impaired bone quality? Endocr Connect 2020; 9:R70-R80. [PMID: 32168472 PMCID: PMC7159263 DOI: 10.1530/ec-19-0531] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 03/13/2020] [Indexed: 11/09/2022]
Abstract
An increasing number of patients worldwide suffer from bone fractures that occur after low intensity trauma. Such fragility fractures are usually associated with advanced age and osteoporosis but also with long-term immobilization, corticosteroid therapy, diabetes mellitus, and other endocrine disorders. It is important to understand the skeletal origins of increased bone fragility in these conditions for preventive and therapeutic strategies to combat one of the most common health problems of the aged population. This review summarizes current knowledge pertaining to the phenomenon of micropetrosis (osteocyte lacunar mineralization). As an indicator of former osteocyte death, micropetrosis is more common in aged bone and osteoporotic bone. Considering that the number of mineralized osteocyte lacunae per bone area can distinguish healthy, untreated osteoporotic and bisphosphonate-treated osteoporotic patients, it could be regarded as a novel structural marker of impaired bone quality. Further research is needed to clarify the mechanism of lacunar mineralization and to explore whether it could be an additional target for preventing or treating bone fragility related to aging and various endocrine diseases.
Collapse
Affiliation(s)
- Petar Milovanovic
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Laboratory for Anthropology and Skeletal Biology, Institute of Anatomy, Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Björn Busse
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Correspondence should be addressed to B Busse:
| |
Collapse
|
22
|
Creecy A, Damrath JG, Wallace JM. Control of Bone Matrix Properties by Osteocytes. Front Endocrinol (Lausanne) 2020; 11:578477. [PMID: 33537002 PMCID: PMC7848033 DOI: 10.3389/fendo.2020.578477] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 12/01/2020] [Indexed: 12/13/2022] Open
Abstract
Osteocytes make up 90-95% of the cellular content of bone and form a rich dendritic network with a vastly greater surface area than either osteoblasts or osteoclasts. Osteocytes are well positioned to play a role in bone homeostasis by interacting directly with the matrix; however, the ability for these cells to modify bone matrix remains incompletely understood. With techniques for examining the nano- and microstructure of bone matrix components including hydroxyapatite and type I collagen becoming more widespread, there is great potential to uncover novel roles for the osteocyte in maintaining bone quality. In this review, we begin with an overview of osteocyte biology and the lacunar-canalicular system. Next, we describe recent findings from in vitro models of osteocytes, focusing on the transitions in cellular phenotype as they mature. Finally, we describe historical and current research on matrix alteration by osteocytes in vivo, focusing on the exciting potential for osteocytes to directly form, degrade, and modify the mineral and collagen in their surrounding matrix.
Collapse
Affiliation(s)
- Amy Creecy
- Department of Biomedical Engineering, Indiana University-Purdue University at Indianapolis, Indianapolis, IN, United States
| | - John G. Damrath
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States
| | - Joseph M. Wallace
- Department of Biomedical Engineering, Indiana University-Purdue University at Indianapolis, Indianapolis, IN, United States
- *Correspondence: Joseph M. Wallace,
| |
Collapse
|
23
|
Chen H, Zhang J, Wang Y, Cheuk KY, Hung ALH, Lam TP, Qiu Y, Feng JQ, Lee WYW, Cheng JCY. Abnormal lacuno-canalicular network and negative correlation between serum osteocalcin and Cobb angle indicate abnormal osteocyte function in adolescent idiopathic scoliosis. FASEB J 2019; 33:13882-13892. [PMID: 31626573 PMCID: PMC6894095 DOI: 10.1096/fj.201901227r] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 09/10/2019] [Indexed: 12/28/2022]
Abstract
Adolescent idiopathic scoliosis (AIS) is a prevalent spinal deformity occurring during peripubertal growth period that affects 1-4% of adolescents globally without clear etiopathogenetic mechanism. Low bone mineral density is an independent and significant prognostic factor for curve progression. Currently, the cause underlying low bone mass in AIS remains elusive. Osteocytes play an important role in bone metabolism and mineral homeostasis, but its role in AIS has not been studied. In the present study, iliac bone tissues were harvested from 21 patients with AIS (mean age of 14.3 ± 2.20 yr old) with a mean Cobb angle of 55.6 ± 10.61° and 13 non-AIS controls (mean age of 16.5 ± 4.79 yr old) intraoperatively. Acid-etched scanning electron microscopy (SEM) images of AIS demonstrated abnormal osteocytes that were more rounded and cobblestone-like in shape and were aligned in irregular clusters with shorter and disorganized canaliculi. Further quantitative analysis with FITC-Imaris technique showed a significant reduction in the canalicular number and length as well as an increase in lacunar volume and area in AIS. SEM with energy-dispersive X-ray spectroscopy analysis demonstrated a lower calcium-to-phosphorus ratio at the perilacunar/canalicular region. Moreover, microindentaion results revealed lower values of Vickers hardness and elastic modulus in AIS when compared with controls. In addition, in the parallel study of 99 AIS (27 with severe Cobb angle of 65.8 ± 14.1° and 72 with mild Cobb angle of 26.6 ± 9.1°) with different curve severity, the serum osteocalcin level was found to be significantly and negatively associated with the Cobb angle. In summary, the findings in this series of studies demonstrated the potential link of abnormal osteocyte lacuno-canalicular network structure and function to the observed abnormal bone mineralization in AIS, which may shed light on etiopathogenesis of AIS.-Chen, H., Zhang, J., Wang, Y., Cheuk, K.-Y., Hung, A. L. H., Lam, T.-P., Qiu, Y., Feng, J. Q., Lee, W. Y. W., Cheng, J. C. Y. Abnormal lacuno-canalicular network and negative correlation between serum osteocalcin and Cobb angle indicate abnormal osteocyte function in adolescent idiopathic scoliosis.
Collapse
Affiliation(s)
- Huanxiong Chen
- Department of Spine and Osteopathic Surgery, The
First Affiliated Hospital of Hainan Medical University, Hai-kou, China
- Department of Orthopaedics and Traumatology, S. H.
Ho Scoliosis Research Laboratory, The Chinese University of Hong Kong, Shatin, NT,
Hong Kong, China
- Joint Scoliosis Research Center of The Chinese
University of Hong Kong–Nanjing University, The Chinese University of Hong
Kong, Hong Kong, China
| | - Jiajun Zhang
- Department of Orthopaedics and Traumatology, S. H.
Ho Scoliosis Research Laboratory, The Chinese University of Hong Kong, Shatin, NT,
Hong Kong, China
- Joint Scoliosis Research Center of The Chinese
University of Hong Kong–Nanjing University, The Chinese University of Hong
Kong, Hong Kong, China
| | - Yujia Wang
- Department of Orthopaedics and Traumatology, S. H.
Ho Scoliosis Research Laboratory, The Chinese University of Hong Kong, Shatin, NT,
Hong Kong, China
- Joint Scoliosis Research Center of The Chinese
University of Hong Kong–Nanjing University, The Chinese University of Hong
Kong, Hong Kong, China
| | - Ka-Yee Cheuk
- Department of Orthopaedics and Traumatology, S. H.
Ho Scoliosis Research Laboratory, The Chinese University of Hong Kong, Shatin, NT,
Hong Kong, China
- Joint Scoliosis Research Center of The Chinese
University of Hong Kong–Nanjing University, The Chinese University of Hong
Kong, Hong Kong, China
| | - Alec L. H. Hung
- Department of Orthopaedics and Traumatology, S. H.
Ho Scoliosis Research Laboratory, The Chinese University of Hong Kong, Shatin, NT,
Hong Kong, China
- Joint Scoliosis Research Center of The Chinese
University of Hong Kong–Nanjing University, The Chinese University of Hong
Kong, Hong Kong, China
| | - Tsz-Ping Lam
- Department of Orthopaedics and Traumatology, S. H.
Ho Scoliosis Research Laboratory, The Chinese University of Hong Kong, Shatin, NT,
Hong Kong, China
- Joint Scoliosis Research Center of The Chinese
University of Hong Kong–Nanjing University, The Chinese University of Hong
Kong, Hong Kong, China
| | - Yong Qiu
- Joint Scoliosis Research Center of The Chinese
University of Hong Kong–Nanjing University, The Chinese University of Hong
Kong, Hong Kong, China
- Spine Surgery, Nanjing Drum Tower Hospital,
Nanjing University, Nanjing, China
| | - Jian Q. Feng
- Department of Biomedical Sciences, Texas
A&M College of Dentistry, Dallas, Texas, USA
| | - Wayne Y. W. Lee
- Department of Orthopaedics and Traumatology, S. H.
Ho Scoliosis Research Laboratory, The Chinese University of Hong Kong, Shatin, NT,
Hong Kong, China
- Joint Scoliosis Research Center of The Chinese
University of Hong Kong–Nanjing University, The Chinese University of Hong
Kong, Hong Kong, China
| | - Jack C. Y. Cheng
- Department of Orthopaedics and Traumatology, S. H.
Ho Scoliosis Research Laboratory, The Chinese University of Hong Kong, Shatin, NT,
Hong Kong, China
- Joint Scoliosis Research Center of The Chinese
University of Hong Kong–Nanjing University, The Chinese University of Hong
Kong, Hong Kong, China
| |
Collapse
|
24
|
Yajima A, Tsuchiya K, Burr DB, Wallace JM, Damrath JD, Inaba M, Tominaga Y, Satoh S, Nakayama T, Tanizawa T, Ogawa H, Ito A, Nitta K. The Importance of Biologically Active Vitamin D for Mineralization by Osteocytes After Parathyroidectomy for Renal Hyperparathyroidism. JBMR Plus 2019; 3:e10234. [PMID: 31768492 PMCID: PMC6874232 DOI: 10.1002/jbm4.10234] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 08/20/2019] [Accepted: 08/26/2019] [Indexed: 11/10/2022] Open
Abstract
Hypomineralized matrix is a factor determining bone mineral density. Increased perilacunar hypomineralized bone area is caused by reduced mineralization by osteocytes. The importance of vitamin D in the mineralization by osteocytes was investigated in hemodialysis patients who underwent total parathyroidectomy (PTX) with immediate autotransplantation of diffuse hyperplastic parathyroid tissue. No previous reports on this subject exist. The study was conducted in 19 patients with renal hyperparathyroidism treated with PTX. In 15 patients, the serum calcium levels were maintained by subsequent administration of alfacalcidol (2.0 μg/day), i.v. calcium gluconate, and oral calcium carbonate for 4 weeks after PTX (group I). This was followed in a subset of 4 patients in group I by a reduced dose of 0.5 μg/day until 1 year following PTX; this was defined as group II. In the remaining 4 patients, who were not in group I, the serum calcium (Ca) levels were maintained without subsequent administration of alfacalcidol (group III). Transiliac bone biopsy specimens were obtained in all groups before and 3 or 4 weeks after PTX to evaluate the change of the hypomineralized bone area. In addition, patients from group II underwent a third bone biopsy 1 year following PTX. A significant decrease of perilacunar hypomineralized bone area was observed 3 or 4 weeks after PTX in all group I and II patients. The area was increased again in the group II patients 1 year following PTX. In group III patients, an increase of the hypomineralized bone area was observed 4 weeks after PTX. The maintenance of a proper dose of vitamin D is necessary for mineralization by osteocytes, which is important to increase bone mineral density after PTX for renal hyperparathyroidism. © 2019 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.
Collapse
Affiliation(s)
- Aiji Yajima
- Department of Anatomy and Cell Biology Indiana University School of Medicine Indianapolis IN USA.,Department of Medicine, Kidney Center Tokyo Women's Medical University Shinjuku-ku, Tokyo Japan
| | - Ken Tsuchiya
- Department of Blood Purification, Kidney Center Tokyo Women's Medical University, Shinjuku-ku Tokyo Japan
| | - David B Burr
- Department of Anatomy and Cell Biology Indiana University School of Medicine Indianapolis IN USA
| | - Joseph M Wallace
- Department of Biomedical Engineering Indiana University, Purdue University Indianapolis IN USA
| | - John D Damrath
- Department of Biomedical Engineering Indiana University, Purdue University Indianapolis IN USA
| | - Masaaki Inaba
- Department of Metabolism, Endocrinology and Molecular Medicine Osaka City University Graduate School of Medicine Osaka Japan
| | - Yoshihiro Tominaga
- Department of Transplant Surgery Nagoya Second Red Cross Hospital Nagoya, Aichi Japan
| | - Shigeru Satoh
- Center for Kidney Disease and Transplantation Akita University Hospital Akita Japan
| | - Takashi Nakayama
- Department of Orthopedic Surgery Towa Hospital Adachi-ku, Tokyo Japan
| | | | - Hajime Ogawa
- Department of Medicine, Division of Nephrology Ogawa Clinic Shinagawa-ku, Tokyo Japan
| | - Akemi Ito
- Ito Bone Histomorphometry Institute Niigata Japan
| | - Kosaku Nitta
- Department of Medicine, Kidney Center Tokyo Women's Medical University Shinjuku-ku, Tokyo Japan
| |
Collapse
|
25
|
Gorustovich AA, Nielsen FH. Effects of Nutritional Deficiency of Boron on the Bones of the Appendicular Skeleton of Mice. Biol Trace Elem Res 2019; 188:221-229. [PMID: 30182352 DOI: 10.1007/s12011-018-1499-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 08/28/2018] [Indexed: 01/20/2023]
Abstract
Scientific evidence has shown the nutritional importance of boron (B) in the remodeling and repair of cancellous bone tissue. However, the effects of the nutritional deficiency of B on the cortical bone tissue of the appendicular skeleton have not yet been described. Thus, a study was performed to histomorphometrically evaluate the density of osteocyte lacunae of cortical bone of mouse femora under conditions of nutritional deficiency of B and to analyze the effects of the deficiency on the biomechanical properties of mouse tibiae. Weaning, 21-day-old male Swiss mice were assigned to the following two groups: controls (B+; n = 10) and experimental (B-; n = 10). Control mice were fed a basal diet containing 3 mg B/kg, whereas experimental mice were fed a B-deficient diet containing 0.07 mg B/kg for 9 weeks. The histological and histomorphometric evaluations of the mice fed a B-deficient diet showed a decrease in the density of osteocyte lacunae in the femoral cortical bone tissue and the evaluation of biomechanical properties showed lower bone rigidity in the tibia.
Collapse
Affiliation(s)
- Alejandro A Gorustovich
- Interdisciplinary Materials Group-IESIING-UCASAL, INTECIN UBA-CONICET, A4400EDD, Salta, Argentina.
| | | |
Collapse
|
26
|
Cummaudo M, Cappella A, Giacomini F, Raffone C, Màrquez-Grant N, Cattaneo C. Histomorphometric analysis of osteocyte lacunae in human and pig: exploring its potential for species discrimination. Int J Legal Med 2019; 133:711-718. [PMID: 30680528 DOI: 10.1007/s00414-018-01989-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 12/19/2018] [Indexed: 11/25/2022]
Abstract
In recent years, several studies have focused on species discrimination of bone fragments by histological analysis. According to literature, the most consistent distinguishing features are Haversian canal and Haversian system areas. Nonetheless, there is a consistent overlap between human and non-human secondary osteon dimensions. One of the features that have never been analyzed for the purpose of species discrimination is the osteocyte lacuna, a small oblong cavity in which the osteocyte is locked in. The aim of this study is to verify whether there are significant quantitative differences between human and pig lacunae within secondary osteons with similar areas. Study sample comprises the midshaft of long bones (humerus, radius, ulna, femur, tibia, and fibula) of a medieval human adult and a juvenile pig. Sixty-eight secondary osteons with similar areas have been selected for each species and a total of 1224 osteocyte lacunae have been measured. For each osteon, the total number of lacunae was counted, and the following measurements were taken: minimum and maximum diameter, area, perimeter, and circularity of nine lacunae divided between inner, intermediate, and outer lacunae. Statistical analysis showed minimal differences between human and pig in the number of lacunae per osteons and in the minimum diameter (P > 0.05). On the contrary, a significant difference (P < 0.001) has been observed in the maximum diameter, perimeter, area, and circularity. Although there is the need for further research on different species and larger sample, these results highlighted the potential for the use of osteocyte lacunae as an additional parameter for species discrimination. Concerning the difference between the dimensions of osteocyte lacunae based on their position within the osteon (inner, intermediate, and outer lacunae), results showed that their size decreases from the cement line towards the Haversian canal both in human and pig.
Collapse
Affiliation(s)
- Marco Cummaudo
- LABANOF (Laboratorio di Antropologia e Odontologia Forense) Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, via Mangiagalli 37, 20133, Milan, Italy.
- Cranfield Forensic Institute, Defence Academy of the United Kingdom, Cranfield University, Shrivenham, SN6 8LA, UK.
| | - Annalisa Cappella
- LABANOF (Laboratorio di Antropologia e Odontologia Forense) Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, via Mangiagalli 37, 20133, Milan, Italy
| | - Francesca Giacomini
- LABANOF (Laboratorio di Antropologia e Odontologia Forense) Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, via Mangiagalli 37, 20133, Milan, Italy
| | - Caterina Raffone
- LABANOF (Laboratorio di Antropologia e Odontologia Forense) Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, via Mangiagalli 37, 20133, Milan, Italy
| | - Nicholas Màrquez-Grant
- Cranfield Forensic Institute, Defence Academy of the United Kingdom, Cranfield University, Shrivenham, SN6 8LA, UK
| | - Cristina Cattaneo
- LABANOF (Laboratorio di Antropologia e Odontologia Forense) Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, via Mangiagalli 37, 20133, Milan, Italy
| |
Collapse
|
27
|
Beresheim AC, Pfeiffer SK, Grynpas MD, Alblas A. Use of backscattered scanning electron microscopy to quantify the bone tissues of mid‐thoracic human ribs. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2019; 168:262-278. [DOI: 10.1002/ajpa.23716] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 09/10/2018] [Accepted: 09/11/2018] [Indexed: 01/08/2023]
Affiliation(s)
- Amy C. Beresheim
- Department of AnthropologyUniversity of Toronto Toronto Ontario Canada
| | - Susan K. Pfeiffer
- Department of AnthropologyUniversity of Toronto Toronto Ontario Canada
- Department of ArchaeologyUniversity of Cape Town Rondebosch Cape Town South Africa
- Department of Anthropology and Center for Advanced Study of Human PaleobiologyGeorge Washington University Washington, D.C
| | - Marc D. Grynpas
- Department of Laboratory Medicine and Pathobiology and Institute for Biomaterials and Biomedical EngineeringUniversity of Toronto Toronto Ontario Canada
- Lunenfeld‐Tanenbaum Research Institute, Mount Sinai Hospital Toronto Ontario Canada
| | - Amanda Alblas
- Division of Anatomy and Histology, Department of Biomedical SciencesStellenbosch University Cape Town South Africa
| |
Collapse
|
28
|
Andronowski JM, Crowder C, Soto Martinez M. Recent advancements in the analysis of bone microstructure: New dimensions in forensic anthropology. Forensic Sci Res 2018; 3:278-293. [PMID: 30788447 PMCID: PMC6374927 DOI: 10.1080/20961790.2018.1483294] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2018] [Accepted: 05/30/2018] [Indexed: 10/29/2022] Open
Abstract
Bone is a mechanically active, three-dimensionally (3D) complex, and dynamic tissue that changes in structure over the human lifespan. Bone tissue exists and remodels in 3D and changes over time, introducing a fourth dimension. The products of the remodelling process, secondary and fragmentary osteons, have been studied substantially using traditional two-dimensional (2D) techniques. As a result, much has been learned regarding the biological information encrypted in the histomorphology of bone, yielding a wealth of information relating to skeletal structure and function. Three-dimensional imaging modalities, however, hold the potential to provide a much more comprehensive understanding of bone microarchitecture. The visualization and analysis of bone using high-resolution 3D imaging will improve current understandings of bone biology and have numerous applications in both biological anthropology and biomedicine. Through recent technological advancements, we can hone current anthropological applications of the analysis of bone microstructure and accelerate research into the third and fourth dimensional realms. This review will explore the methodological approaches used historically by anthropologists to assess cortical bone microstructure, spanning from histology to current ex vivo imaging modalities, discuss the growing capabilities of in vivo imaging, and conclude with an introduction of novel non-histological modalities for investigating bone quality.
Collapse
|
29
|
Sharma D, Larriera AI, Palacio-Mancheno PE, Gatti V, Fritton JC, Bromage TG, Cardoso L, Doty SB, Fritton SP. The effects of estrogen deficiency on cortical bone microporosity and mineralization. Bone 2018; 110:1-10. [PMID: 29357314 PMCID: PMC6377161 DOI: 10.1016/j.bone.2018.01.019] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 01/09/2018] [Accepted: 01/15/2018] [Indexed: 12/22/2022]
Abstract
Recent studies have demonstrated matrix-mineral alterations in bone tissue surrounding osteocytes in estrogen-deficient animals. While cortical bone porosity has been shown to be a contributor to the mechanical properties of bone tissue, little analysis has been done to investigate the effects of estrogen deficiency on bone's microporosities, including the vascular and osteocyte lacunar porosities. In this study we examined alterations in cortical bone microporosity, mineralization, and cancellous bone architecture due to estrogen deficiency in the ovariectomized rat model of postmenopausal osteoporosis. Twenty-week-old female Sprague-Dawley rats were subjected to either ovariectomy or sham surgery. Six weeks post-surgery tibiae were analyzed using high-resolution micro-CT, backscattered electron imaging, nanoindentation, and dynamic histomorphometry. Estrogen deficiency caused an increase in cortical bone vascular porosity, with enlarged vascular pores and little change in tissue mineral density in the proximal tibial metaphysis. Measurements of cancellous architecture corresponded to previous studies reporting a decrease in bone volume fraction, an increase in trabecular separation, and a decrease in trabecular number in the proximal tibia due to estrogen deficiency. Nanoindentation results showed no differences in matrix stiffness in osteocyte-rich areas of the proximal tibia of estrogen-deficient rats, and bone labeling and backscattered electron imaging showed no significant changes in mineralization around the vascular pores. The findings demonstrate local surface alterations of vascular pores due to estrogen deficiency. An increase in cortical vascular porosity may diminish bone strength as well as alter bone mechanotransduction via interstitial fluid flow, both of which could contribute to bone fragility during postmenopausal osteoporosis.
Collapse
Affiliation(s)
- Divya Sharma
- Department of Biomedical Engineering, The City College of New York, New York, NY 10031, United States
| | - Adriana I Larriera
- Department of Biomedical Engineering, The City College of New York, New York, NY 10031, United States
| | - Paolo E Palacio-Mancheno
- Department of Biomedical Engineering, The City College of New York, New York, NY 10031, United States
| | - Vittorio Gatti
- Department of Biomedical Engineering, The City College of New York, New York, NY 10031, United States
| | - J Christopher Fritton
- Department of Orthopaedics, New Jersey Medical School, Rutgers University, Newark, NJ 07103, United States
| | - Timothy G Bromage
- Department of Biomaterials, New York University College of Dentistry, New York, NY 10010, United States
| | - Luis Cardoso
- Department of Biomedical Engineering, The City College of New York, New York, NY 10031, United States
| | - Stephen B Doty
- Research Division, Hospital for Special Surgery, New York, NY 10021, United States
| | - Susannah P Fritton
- Department of Biomedical Engineering, The City College of New York, New York, NY 10031, United States.
| |
Collapse
|
30
|
Abstract
PURPOSE OF REVIEW Solute transport in the lacunar-canalicular system (LCS) plays important roles in osteocyte metabolism and cell-cell signaling. This review will summarize recent studies that establish pericellular matrix (PCM), discovered inside the LCS, as a crucial regulator of solute transport in bone. RECENT FINDINGS Utilizing confocal imaging and mathematical modeling, recent studies successfully quantified molecular diffusion and convection in the LCS as well as the size-dependent sieving effects of the PCM, leading to the quantification of the effective PCM fiber spacing (10 to 17 nm) in murine adult bones. Perlecan/HSPG2, a large linear proteoglycan, was identified to be an essential PCM component. The PCM-filled LCS is bone's chromatographic column, where fluid/solute transport to and from the osteocytes is regulated. The chemical composition, deposition rate, and turnover rate of the osteocyte PCM should be further defined to better understand osteocyte physiology and bone metabolism.
Collapse
Affiliation(s)
- Liyun Wang
- Center for Biomechanical Research, Department of Mechanical Engineering, University of Delaware, 130 Academy Street, Newark, DE, 19716, USA.
| |
Collapse
|
31
|
Popp KL, Hughes JM, Martinez-Betancourt A, Scott M, Turkington V, Caksa S, Guerriere KI, Ackerman KE, Xu C, Unnikrishnan G, Reifman J, Bouxsein ML. Bone mass, microarchitecture and strength are influenced by race/ethnicity in young adult men and women. Bone 2017; 103:200-208. [PMID: 28712877 DOI: 10.1016/j.bone.2017.07.014] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 06/18/2017] [Accepted: 07/12/2017] [Indexed: 02/05/2023]
Abstract
UNLABELLED Lower rates of fracture in both Blacks compared to Whites, and men compared to women are not completely explained by differences in bone mineral density (BMD). Prior evidence suggests that more favorable cortical bone microarchitecture may contribute to reduced fracture rates in older Black compared to White women, however it is not known whether these differences are established in young adulthood or develop during aging. Moreover, prior studies using high-resolution pQCT (HR-pQCT) have reported outcomes from a fixed-scan location, which may confound sex- and race/ethnicity-related differences in bone structure. PURPOSE We determined differences in bone mass, microarchitecture and strength between young adult Black and White men and women. METHODS We enrolled 185 young adult (24.2±3.4yrs) women (n=51 Black, n=50 White) and men (n=34 Black, n=50 White) in this cross-sectional study. We used dual-energy X-ray absorptiometry (DXA) to determine areal BMD (aBMD) at the femoral neck (FN), total hip (TH) and lumbar spine (LS), as well as HR-pQCT to assess bone microarchitecture and failure load by micro-finite element analysis (μFEA) at the distal tibia (4% of tibial length). We used two-way ANOVA to compare bone outcomes, adjusted for age, height, weight and physical activity. RESULTS The effect of race/ethnicity on bone outcomes did not differ by sex, and the effect of sex on bone outcomes did not differ by race/ethnicty. After adjusting for covariates, Blacks had significantly greater FN, TH and LS aBMD compared to Whites (p<0.05 for all). Blacks also had greater cortical area, vBMD, and thickness, and lower cortical porosity, with greater trabecular thickness and total vBMD compared to Whites. μFEA-estimated FL was significantly higher among Blacks compared to Whites. Men had significantly greater total vBMD, trabecular thickness and cortical area and thickness, but greater cortical porosity than women, the net effects being a higher failure load in men than women. CONCLUSION These findings demonstrate that more favorable bone microarchitecture in Blacks compared to Whites and in men compared to women is established by young adulthood. Advantageous bone strength among Blacks and men likely contributes to their lower risk of fractures throughout life compared to their White and women counterparts.
Collapse
Affiliation(s)
- Kristin L Popp
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, 50 Blossom Street, THR-1051, Boston, MA 02114, USA.
| | - Julie M Hughes
- Military Performance Division, United States Army Research Institute of Environmental Medicine, 10 General Greene Ave, Natick, MA 01760, USA
| | | | - Matthew Scott
- Endocrine Unit, Massachusetts General Hospital, 50 Blossom Street, THR-1051, Boston, MA 02114, USA
| | - Victoria Turkington
- Endocrine Unit, Massachusetts General Hospital, 50 Blossom Street, THR-1051, Boston, MA 02114, USA
| | - Signe Caksa
- Endocrine Unit, Massachusetts General Hospital, 50 Blossom Street, THR-1051, Boston, MA 02114, USA
| | - Katelyn I Guerriere
- Military Performance Division, United States Army Research Institute of Environmental Medicine, 10 General Greene Ave, Natick, MA 01760, USA
| | - Kathryn E Ackerman
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, 50 Blossom Street, THR-1051, Boston, MA 02114, USA; Division of Sports Medicine, Boston Children's Hospital, 319 Longwood Avenue, Boston, MA, USA 02115
| | - Chun Xu
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, United States Army Medical Research and Materiel Command, 2405 Whittier Drive, Suite 200, Frederick, MD 21702, USA
| | - Ginu Unnikrishnan
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, United States Army Medical Research and Materiel Command, 2405 Whittier Drive, Suite 200, Frederick, MD 21702, USA
| | - Jaques Reifman
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, United States Army Medical Research and Materiel Command, 2405 Whittier Drive, Suite 200, Frederick, MD 21702, USA
| | - Mary L Bouxsein
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, 50 Blossom Street, THR-1051, Boston, MA 02114, USA; Center for Advanced Orthopedic Studies, Beth Israel Deaconess Medical Center, Harvard Medical School, One Overland Street, Boston, MA 02215, USA; Department of Orthopedic Surgery, Harvard Medical School, One Overland Street, Boston, MA, 02215, USA
| |
Collapse
|
32
|
Mosey H, Núñez JA, Goring A, Clarkin CE, Staines KA, Lee PD, Pitsillides AA, Javaheri B. Sost Deficiency does not Alter Bone's Lacunar or Vascular Porosity in Mice. FRONTIERS IN MATERIALS 2017; 4:27. [PMID: 29349060 PMCID: PMC5769812 DOI: 10.3389/fmats.2017.00027] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
SCLEROSTIN (Sost) is expressed predominantly in osteocytes acting as a negative regulator of bone formation. In humans, mutations in the SOST gene lead to skeletal overgrowth and increased bone mineral density, suggesting that SCLEROSTIN is a key regulator of bone mass. The function of SCLEROSTIN as an inhibitor of bone formation is further supported by Sost knockout (KO) mice which display a high bone mass with elevated bone formation. Previous studies have indicated that Sost exerts its effect on bone formation through Wnt-mediated regulation of osteoblast differentiation, proliferation, and activity. Recent in vitro studies have also suggested that SCLEROSTIN regulates angiogenesis and osteoblast-to-osteocyte transition. Despite this wealth of knowledge of the mechanisms responsible for SCLEROSTIN action, no previous studies have examined whether SCLEROSTIN regulates osteocyte and vascular configuration in cortices of mouse tibia. Herein, we image tibiae from Sost KO mice and their wild-type (WT) counterparts with high-resolution CT to examine whether lack of SCLEROSTIN influences the morphometric properties of lacunae and vascular canal porosity relating to osteocytes and vessels within cortical bone. Male Sost KO and WT mice (n = 6/group) were sacrificed at 12 weeks of age. Fixed tibiae were analyzed using microCT to examine cortical bone mass and architecture. Then, samples were imaged by using benchtop and synchrotron nano-computed tomography at the tibiofibular junction. Our data, consistent with previous studies show that, Sost deficiency leads to significant enhancement of bone mass by cortical thickening and bigger cross-sectional area and we find that this occurs without modifications of tibial ellipticity, a measure of bone shape. In addition, our data show that there are no significant differences in any lacunar or vascular morphometric or geometric parameters between Sost KO mouse tibia and WT counterparts. We, therefore, conclude that the significant increases in bone mass induced by Sost deficiency are not accompanied by any significant modification in the density, organization, or shape of osteocyte lacunae or vascular content within the cortical bone. These data may imply that SCLEROSTIN does not modify the frequency of osteocytogenic recruitment of osteoblasts to initiate terminal osteocytic differentiation in mice.
Collapse
Affiliation(s)
- Henry Mosey
- Skeletal Biology Group, Comparative Biomedical Sciences, The Royal Veterinary College, London, United Kingdom
| | - Juan A. Núñez
- Faculty of Natural and Environmental Sciences, Biological Sciences, University of Southampton, Southampton, United Kingdom
| | - Alice Goring
- Faculty of Natural and Environmental Sciences, Biological Sciences, University of Southampton, Southampton, United Kingdom
| | - Claire E. Clarkin
- Faculty of Natural and Environmental Sciences, Biological Sciences, University of Southampton, Southampton, United Kingdom
| | - Katherine A. Staines
- School of Applied Sciences, Edinburgh Napier University, Edinburgh, United Kingdom
| | - Peter D. Lee
- Manchester X-Ray Imaging Facility, University of Manchester, Manchester, United Kingdom
| | - Andrew A. Pitsillides
- Skeletal Biology Group, Comparative Biomedical Sciences, The Royal Veterinary College, London, United Kingdom
| | - Behzad Javaheri
- Skeletal Biology Group, Comparative Biomedical Sciences, The Royal Veterinary College, London, United Kingdom
| |
Collapse
|
33
|
Tong X, Malo MKH, Burton IS, Jurvelin JS, Isaksson H, Kröger H. Histomorphometric and osteocytic characteristics of cortical bone in male subtrochanteric femoral shaft. J Anat 2017; 231:708-717. [PMID: 28786101 DOI: 10.1111/joa.12670] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/12/2017] [Indexed: 12/12/2022] Open
Abstract
The histomorphometric properties of the subtrochanteric femoral region have rarely been investigated. The aim of this study was to investigate the age-associated variations and regional differences of histomorphometric and osteocytic properties in the cortical bone of the subtrochanteric femoral shaft, and the association between osteocytic and histological cortical bone parameters. Undecalcified histological sections of the subtrochanteric femoral shaft were obtained from cadavers (n = 20, aged 18-82 years, males). They were cut and stained using modified Masson-Goldner stain. Histomorphometric parameters of cortical bone were analysed with ×50 and ×100 magnification after identifying cortical bone boundaries using our previously validated method. Within cortical bone areas, only complete osteons with typical concentric lamellae and cement line were selected and measured. Osteocytic parameters of cortical bone were analyzed under phase contrast microscopy and epifluorescence within microscopic fields (0.55 mm2 for each). The cortical widths of the medial and lateral quadrants were significantly higher than other quadrants (P < 0.01). Osteonal area per cortical bone area was lower and cortical porosities were higher in the posterior quadrant than in the other quadrants (P < 0.05). Osteocyte lacunar number per cortical bone area was found higher in the young subjects (≤ 50 years) than in the older ones (> 50 years) both before and after adjustments for body height and weight (P < 0.05). Moreover, significant but low correlations were found between the cortical bone and osteocytic parameters (0.20 ≤ R2 ≤ 0.35, P < 0.05). It can be concluded that in healthy males, the cortical histomorphometric parameters differ between the anatomical regions of the subtrochanteric femoral shaft, and are correlated with the osteocytic parameters from the same site. These findings may be of use when discussing mechanisms that predispose patients to decreasing bone strength.
Collapse
Affiliation(s)
- Xiaoyu Tong
- Kuopio Musculoskeletal Research Unit (KMRU), Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland.,Department of Applied Physics, University of Eastern Finland, Kuopio, Finland
| | - Markus K H Malo
- Department of Applied Physics, University of Eastern Finland, Kuopio, Finland
| | - Inari S Burton
- Kuopio Musculoskeletal Research Unit (KMRU), Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland.,Department of Applied Physics, University of Eastern Finland, Kuopio, Finland
| | - Jukka S Jurvelin
- Department of Applied Physics, University of Eastern Finland, Kuopio, Finland.,Diagnostic Imaging Centre, Kuopio University Hospital, Kuopio, Finland
| | - Hanna Isaksson
- Department of Biomedical Engineering, Department of Orthopaedics, Lund University, Lund, Sweden
| | - Heikki Kröger
- Kuopio Musculoskeletal Research Unit (KMRU), Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland.,Department of Orthopaedics, Traumatology, and Hand Surgery, Kuopio University Hospital, Kuopio, Finland
| |
Collapse
|
34
|
Ashique AM, Hart LS, Thomas CDL, Clement JG, Pivonka P, Carter Y, Mousseau DD, Cooper DML. Lacunar-canalicular network in femoral cortical bone is reduced in aged women and is predominantly due to a loss of canalicular porosity. Bone Rep 2017; 7:9-16. [PMID: 28752112 PMCID: PMC5517690 DOI: 10.1016/j.bonr.2017.06.002] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 05/29/2017] [Accepted: 06/27/2017] [Indexed: 11/29/2022] Open
Abstract
The lacunar-canalicular network (LCN) of bone contains osteocytes and their dendritic extensions, which allow for intercellular communication, and are believed to serve as the mechanosensors that coordinate the processes of bone modeling and remodeling. Imbalances in remodeling, for example, are linked to bone disease, including fragility associated with aging. We have reported that there is a reduction in scale for one component of the LCN, osteocyte lacunar volume, across the human lifespan in females. In the present study, we explore the hypothesis that canalicular porosity also declines with age. To visualize the LCN and to determine how its components are altered with aging, we examined samples from young (age: 20–23 y; n = 5) and aged (age: 70–86 y; n = 6) healthy women donors utilizing a fluorescent labelling technique in combination with confocal laser scanning microscopy. A large cross-sectional area of cortical bone spanning the endosteal to periosteal surfaces from the anterior proximal femoral shaft was examined in order to account for potential trans-cortical variation in the LCN. Overall, we found that LCN areal fraction was reduced by 40.6% in the samples from aged women. This reduction was due, in part, to a reduction in lacunar density (21.4% decline in lacunae number per given area of bone), but much more so due to a 44.6% decline in canalicular areal fraction. While the areal fraction of larger vascular canals was higher in endosteal vs. periosteal regions for both age groups, no regional differences were observed in the areal fractions of the LCN and its components for either age group. Our data indicate that the LCN is diminished in aged women, and is largely due to a decline in the canalicular areal fraction, and that, unlike vascular canal porosity, this diminished LCN is uniform across the cortex. The lacunar-canalicular network (LCN) is reduced by 40.6% in aged women The lacunar density (lacunae number per given area of bone) is reduced by 21.4% in aged women The reduction in LCN in aged women is primarily due to a 44.6% loss of canaliculi No endosteal vs. periosteal regional differences were observed in the LCN and its components in either young or aged women A reduction in canaliculi with age may contribute to bone fragility in aged women
Collapse
Affiliation(s)
- A M Ashique
- Department of Anatomy & Cell Biology, University of Saskatchewan, Saskatoon, SK, Canada
| | - L S Hart
- Department of Anatomy & Cell Biology, University of Saskatchewan, Saskatoon, SK, Canada
| | - C D L Thomas
- Melbourne Dental School, University of Melbourne, Melbourne, VIC, Australia
| | - J G Clement
- Melbourne Dental School, University of Melbourne, Melbourne, VIC, Australia
| | - P Pivonka
- St. Vincent's Department of Surgery, University of Melbourne, Melbourne, VIC, Australia.,School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane, QLD, Australia
| | - Y Carter
- Department of Radiology, University of Massachusetts Medical School, Worcester, MA, USA
| | - D D Mousseau
- Department of Psychiatry, University of Saskatchewan, Saskatoon, SK, Canada
| | - D M L Cooper
- Department of Anatomy & Cell Biology, University of Saskatchewan, Saskatoon, SK, Canada
| |
Collapse
|
35
|
Akhter MP, Kimmel DB, Lappe JM, Recker RR. Effect of Macroanatomic Bone Type and Estrogen Loss on Osteocyte Lacunar Properties in Healthy Adult Women. Calcif Tissue Int 2017; 100:619-630. [PMID: 28251257 DOI: 10.1007/s00223-017-0247-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2016] [Accepted: 01/30/2017] [Indexed: 12/27/2022]
Abstract
This is the first study to examine clinical human bone specimens by three-dimensional imaging to characterize osteocyte lacunar properties as a function of macroanatomic bone type and estrogen loss. We applied laboratory-based instrumentation [3D X-ray microscope (3DXRM), MicroXCT-200; Carl Zeiss/Xradia, Inc.] that reaches the same resolution as synchrotron microscopy. We used serial transiliac bone biopsy specimens to examine the effect of macroanatomic bone type and estrogen status on osteocyte lacunar properties. These properties include lacunar size (volume, axes lengths of the ellipsoidal lacunar voids), distribution (density, average near-neighbor lacunar distance), and shape factors (sphericity ratio, average eigenvalues, degree of equancy, elongation, and flatness) in both cortical and trabecular bone tissue. The lacunar properties (volume, surface area, density, near-neighbor distance, etc.) and the shape factors (E1, L1, L2, degree of equancy, degree of elongation) were different between cortical and trabecular bone regardless of estrogen status. In cortical bone and trabecular nodes, the lacunar void volume and surface area were either smaller or tended to be smaller in postmenopausal as compared to premenopausal women. The void volume-to-bone volume ratio of cortical bone showed declining trends with estrogen loss. While there were differences between trabecular and cortical bone tissue, the lacunar void sphericity ratio for trabecular struts shows decreasing trends in postmenopausal women. These data suggest that using 3DXRM can provide new insight into osteocyte lacunar properties in transiliac bone biopsies from patients with various skeletal disease/conditions and pharmaceutical treatments.
Collapse
Affiliation(s)
- Mohammed P Akhter
- Osteoporosis Research Center (ORC), Creighton University of School of Medicine, Suite #4820, 601 North 30th Street, Omaha, NE, 68131, USA.
| | - D B Kimmel
- Osteoporosis Research Center (ORC), Creighton University of School of Medicine, Suite #4820, 601 North 30th Street, Omaha, NE, 68131, USA
| | - J M Lappe
- Osteoporosis Research Center (ORC), Creighton University of School of Medicine, Suite #4820, 601 North 30th Street, Omaha, NE, 68131, USA
| | - R R Recker
- Osteoporosis Research Center (ORC), Creighton University of School of Medicine, Suite #4820, 601 North 30th Street, Omaha, NE, 68131, USA
| |
Collapse
|
36
|
Abstract
When normal physiologic functions go awry, disorders and disease occur. This is universal; even for the osteocyte, a cell embedded within the mineralized matrix of bone. It was once thought that this cell was simply a placeholder in bone. Within the last decade, the number of studies of osteocytes has increased dramatically, leading to the discovery of novel functions of these cells. With the discovery of novel physiologic functions came the discoveries of how these cells can also be responsible for not only bone diseases and disorders, but also those of the kidney, heart, and potentially muscle.
Collapse
Affiliation(s)
- Lynda F Bonewald
- Indiana Center for Musculoskeletal Health, VanNuys Medical Science Building, MS 5055, 635 Barnhill Drive, Indianapolis, IN 46202, USA; Department of Anatomy and Cell Biology, VanNuys Medical Science Building, MS 5035, Indianapolis, IN 46202, USA; Department of Orthopaedic Surgery, 1120 West Michigan Street, Suite 600, Indianapolis, IN 46202, USA.
| |
Collapse
|
37
|
Luo D, Ren H, Li T, Lian K, Lin D. Rapamycin reduces severity of senile osteoporosis by activating osteocyte autophagy. Osteoporos Int 2016; 27:1093-1101. [PMID: 26395886 DOI: 10.1007/s00198-015-3325-5] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2015] [Accepted: 09/14/2015] [Indexed: 12/22/2022]
Abstract
SUMMARY Osteocyte is the orchestrator of bone remolding and decline in osteocyte autophagy is involved in senile osteoporosis. Our results suggested that rapamycin, at least in part by activating osteocyte autophagy, reduced the severity of age-related bone changes in trabecular bone of old male rats. INTRODUCTION Previous literatures have showed that osteocyte is the orchestrator of bone remolding and age-related decline in osteocyte number is associated with senile osteoporosis. Autophagy is an important cellular protective mechanism which can preserve osteocyte viability and failure of autophagy in osteocyte with age has been linked to senile osteoporosis. The purpose of this study was to explore whether rapamycin, one activator of autophagy, has protective effects on senile osteoporosis through inducing osteocyte autophagy. METHODS Fifty-two 24-month-old male Sprague-Dawley (SD) rats were randomly divided into two groups. Rapamycin (1 mg/kg weight/day) or DMSO vehicle control was administered intraperitoneally for 12 weeks. BMD and bone microstructure were determined by Micro-CT. Fluorochrome labeling of the bones was performed to measure the mineral apposition rate (MAR). TRAP staining was performed to evaluate osteoclast number. The plasma levels of bone turnover markers were also analyzed. The effects of rapamycin on osteocyte autophagy were determined by immunohistochemistry, Western blot, and q-PCR. TUNEL was used to determine the prevalence of osteocyte apoptosis. RESULTS Micro-CT evaluation demonstrated that rapamycin had a protective effect on age-related bone loss in trabecular bone. Besides, rapamycin resulted in an obvious increase of MAR and a decrease of osteoclast number in contrast to the control group. Furthermore, rapamycin also induced autophagy in osteocyte demonstrated by increased LC3-positive osteocyte and increased LC3 turnover. In addition, rats treated with rapamycin exhibited decreased apoptosis of osteocyte determined by TUNEL. CONCLUSIONS These results suggested that rapamycin, at least in part by activating osteocyte autophagy, reduced the severity of age-related bone changes in trabecular bone of old male rats. Therefore, rapamycin might be a feasible therapeutic approach for senile osteoporosis.
Collapse
Affiliation(s)
- D Luo
- Department of Orthopaedic Surgery, Orthopaedic Center of People's Liberation Army, The Affiliated Southeast Hospital of Xiamen University, Zhangzhou, 363000, China
| | - H Ren
- Biobank, The First Affiliated Hospital of Xiamen University, Xiamen, 361003, China
| | - T Li
- Department of Orthopaedic Surgery, Orthopaedic Center of People's Liberation Army, The Affiliated Southeast Hospital of Xiamen University, Zhangzhou, 363000, China
| | - K Lian
- Department of Orthopaedic Surgery, Orthopaedic Center of People's Liberation Army, The Affiliated Southeast Hospital of Xiamen University, Zhangzhou, 363000, China
| | - D Lin
- Department of Orthopaedic Surgery, Orthopaedic Center of People's Liberation Army, The Affiliated Southeast Hospital of Xiamen University, Zhangzhou, 363000, China.
| |
Collapse
|
38
|
Brotto M, Bonewald L. Bone and muscle: Interactions beyond mechanical. Bone 2015; 80:109-114. [PMID: 26453500 PMCID: PMC4600532 DOI: 10.1016/j.bone.2015.02.010] [Citation(s) in RCA: 193] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Revised: 01/27/2015] [Accepted: 02/08/2015] [Indexed: 02/08/2023]
Abstract
The musculoskeletal system is significantly more complex than portrayed by traditional reductionist approaches that have focused on and studied the components of this system separately. While bone and skeletal muscle are the two largest tissues within this system, this system also includes tendons, ligaments, cartilage, joints and other connective tissues along with vascular and nervous tissues. Because the main function of this system is locomotion, the mechanical interaction among the major players of this system is essential for the many shapes and forms observed in vertebrates and even in invertebrates. Thus, it is logical that the mechanical coupling theories of musculoskeletal development exert a dominant influence on our understanding of the biology of the musculoskeletal system, because these relationships are relatively easy to observe, measure, and perturb. Certainly much less recognized is the molecular and biochemical interaction among the individual players of the musculoskeletal system. In this brief review article, we first introduce some of the key reasons why the mechanical coupling theory has dominated our view of bone-muscle interactions followed by summarizing evidence for the secretory nature of bones and muscles. Finally, a number of highly physiological questions that cannot be answered by the mechanical theories alone will be raised along with different lines of evidence that support both a genetic and a biochemical communication between bones and muscles. It is hoped that these discussions will stimulate new insights into this fertile and promising new way of defining the relationships between these closely related tissues. Understanding the cellular and molecular mechanisms responsible for biochemical communication between bone and muscle is important not only from a basic research perspective but also as a means to identify potential new therapies for bone and muscle diseases, especially for when they co-exist. This article is part of a Special Issue entitled "Muscle Bone Interactions".
Collapse
Affiliation(s)
- Marco Brotto
- Muscle Biology Research Group-MUBIG, UMKC School of Nursing & Health Studies, 2464 Charlotte, USA; UMKC School of Medicine, 2464 Charlotte, USA
| | - Lynda Bonewald
- Bone Biology/Mineralized Tissue Research Program, Department of Oral and Craniofacial Sciences, UMKC School of Dentistry, 650 East 25th Street, Kansas City, MO 64108, USA
| |
Collapse
|
39
|
Maycas M, Ardura JA, de Castro LF, Bravo B, Gortázar AR, Esbrit P. Role of the Parathyroid Hormone Type 1 Receptor (PTH1R) as a Mechanosensor in Osteocyte Survival. J Bone Miner Res 2015; 30:1231-44. [PMID: 25529820 DOI: 10.1002/jbmr.2439] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Revised: 11/22/2014] [Accepted: 12/22/2014] [Indexed: 12/13/2022]
Abstract
Osteocytes have a major role in the control of bone remodeling. Mechanical stimulation decreases osteocyte apoptosis and promotes bone accrual, whereas skeletal unloading is deleterious in both respects. PTH1R ablation or overexpression in osteocytes in mice produces trabecular bone loss or increases bone mass, respectively. The latter effect was related to a decreased osteocyte apoptosis. Here, the putative role of PTH1R activation in osteocyte protection conferred by mechanical stimulation was assessed. Osteocytic MLO-Y4 cells were subjected to mechanical stimuli represented by hypotonic shock (216 mOsm/kg) or pulsatile fluid flow (8 Hz, 10 dynes/cm(2)) for a short pulse (10 min), with or without PTH1R antagonists or after transfection with specific PTHrP or PTH1R siRNA. These mechanical stimuli prevented cell death induced within 6 hours by etoposide (50 μM), related to PTHrP overexpression; and this effect was abolished by the calcium antagonist verapamil (1 μM), a phospholipase C (PLC) inhibitor (U73122; 10 μM), and a PKA activation inhibitor, Rp-cAMPS (25 μM), in these cells. Each mechanical stimulus also rapidly induced β-catenin stabilization and nuclear ERK translocation, which were inhibited by the PTH1R antagonist PTHrP(7-34) (1 μM), or PTH1R siRNA, and mimicked by PTHrP(1-36) (100 nM). Mechanical stretching by hypotonic shock did not affect cAMP production but rapidly (<1 min) stimulated Ca(i)(2+) transients in PTH1R-overexpressing HEK-293 cells and in MLO-Y4 cells, in which calcium signaling was unaffected by the presence of a PTHrP antiserum or PTHrP siRNA but inhibited by knocking down PTH1R. These novel findings indicate that PTH1R is an important component of mechanical signal transduction in osteocytic MLO-Y4 cells, and that PTH1R activation by PTHrP-independent and dependent mechanisms has a relevant role in the prosurvival action of mechanical stimulus in these cells.
Collapse
Affiliation(s)
- Marta Maycas
- Instituto de, Investigación Sanitaria (IIS)-, Fundación Jiménez Díaz, Universidad Autónoma de Madrid (UAM) and Red Temática de Investigación Cooperativa en Envejecimiento y Fragilidad (RETICEF), Madrid, Spain
| | - Juan A Ardura
- Instituto de, Investigación Sanitaria (IIS)-, Fundación Jiménez Díaz, Universidad Autónoma de Madrid (UAM) and Red Temática de Investigación Cooperativa en Envejecimiento y Fragilidad (RETICEF), Madrid, Spain
| | - Luis F de Castro
- Instituto de Medicina Molecular Aplicada (IMMA), Facultad de Medicina, Universidad San Pablo-CEU, Madrid, Spain
| | - Beatriz Bravo
- Instituto de Medicina Molecular Aplicada (IMMA), Facultad de Medicina, Universidad San Pablo-CEU, Madrid, Spain
| | - Arancha R Gortázar
- Instituto de Medicina Molecular Aplicada (IMMA), Facultad de Medicina, Universidad San Pablo-CEU, Madrid, Spain
| | - Pedro Esbrit
- Instituto de, Investigación Sanitaria (IIS)-, Fundación Jiménez Díaz, Universidad Autónoma de Madrid (UAM) and Red Temática de Investigación Cooperativa en Envejecimiento y Fragilidad (RETICEF), Madrid, Spain
| |
Collapse
|
40
|
Geissler JR, Bajaj D, Fritton JC. American Society of Biomechanics Journal of Biomechanics Award 2013: cortical bone tissue mechanical quality and biological mechanisms possibly underlying atypical fractures. J Biomech 2015; 48:883-94. [PMID: 25683519 PMCID: PMC4380555 DOI: 10.1016/j.jbiomech.2015.01.032] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 01/20/2015] [Indexed: 01/15/2023]
Abstract
The biomechanics literature contains many well-understood mechanisms behind typical fracture types that have important roles in treatment planning. The recent association of “atypical” fractures with long-term use of drugs designed to prevent osteoporosis has renewed interest in the effects of agents on bone tissue-level quality. While this class of fracture was recognized prior to the introduction of the anti-resorptive bisphosphonate drugs and recently likened to stress fractures, the mechanism(s) that lead to atypical fractures have not been definitively identified. Thus, a causal relationship between these drugs and atypical fracture has not been established. Physicians, bioengineers and others interested in the biomechanics of bone are working to improve fracture-prevention diagnostics, and the design of treatments to avoid this serious side-effect in the future. This review examines the mechanisms behind the bone tissue damage that may produce the atypical fracture pattern observed increasingly with long-term bisphosphonate use. Our recent findings and those of others reviewed support that the mechanisms behind normal, healthy excavation and tunnel filling by bone remodeling units within cortical tissue strengthen mechanical integrity. The ability of cortical bone to resist the damage induced during cyclic loading may be altered by the reduced remodeling and increased tissue age resulting from long-term bisphosphonate treatment. Development of assessments for such potential fractures would restore confidence in pharmaceutical treatments that have the potential to spare millions in our aging population from the morbidity and death that often follow bone fracture.
Collapse
Affiliation(s)
- Joseph R Geissler
- Department of Orthopaedics, New Jersey Medical School, Rutgers University, 205 S. Orange Avenue, Newark, NJ 07103, USA; Joint Program in Biomedical Engineering, Rutgers Biomedical and Health Sciences, and the New Jersey Institute of Technology, Newark, NJ, USA.
| | - Devendra Bajaj
- Department of Orthopaedics, New Jersey Medical School, Rutgers University, 205 S. Orange Avenue, Newark, NJ 07103, USA.
| | - J Christopher Fritton
- Department of Orthopaedics, New Jersey Medical School, Rutgers University, 205 S. Orange Avenue, Newark, NJ 07103, USA; Joint Program in Biomedical Engineering, Rutgers Biomedical and Health Sciences, and the New Jersey Institute of Technology, Newark, NJ, USA.
| |
Collapse
|
41
|
Oliveira PS, Rodrigues JA, Shibli JA, Piattelli A, Iezzi G, Perrotti V. Influence of osteoporosis on the osteocyte density of human mandibular bone samples: a controlled histological human study. Clin Oral Implants Res 2014; 27:325-8. [DOI: 10.1111/clr.12538] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/21/2014] [Indexed: 01/11/2023]
Affiliation(s)
- Pablo S. Oliveira
- Department of Periodontology and Oral Implantology; Dental Research Division; Guarulhos University; Guarulhos Brazil
| | - José A. Rodrigues
- Department of Periodontology and Oral Implantology; Dental Research Division; Guarulhos University; Guarulhos Brazil
| | - Jamil A. Shibli
- Department of Periodontology and Oral Implantology; Dental Research Division; Guarulhos University; Guarulhos Brazil
| | - Adriano Piattelli
- Department of Medical, Oral and Biotechnological Sciences; University of Chieti-Pescara; Chieti Italy
| | - Giovanna Iezzi
- Department of Medical, Oral and Biotechnological Sciences; University of Chieti-Pescara; Chieti Italy
| | - Vittoria Perrotti
- Department of Medical, Oral and Biotechnological Sciences; University of Chieti-Pescara; Chieti Italy
| |
Collapse
|
42
|
Abstract
PURPOSE OF REVIEW Discovery of the Wnt signaling pathway and understanding the central role of osteocyte in skeletal homeostasis have been the major advances in skeletal biology over the past decade. Sclerostin, secreted mainly (but not exclusively) by osteocytes, has emerged as a key player in skeletal homeostasis. This review highlights the most relevant recent advances. RECENT FINDINGS Sclerostin by inhibiting Wnt signaling pathway decreases bone formation and osteoblast differentiation and promotes osteoblast apoptosis. Ability to measure serum sclerostin levels better clarified the role of sclerostin in various physiologic and pathologic states. Early clinical trials with antibodies to sclerostin have produced robust increases in bone mineral density, and fracture prevention trials are underway. SUMMARY Since the discovery of Wnt signaling pathway and sclerostin's association with high bone mass, there has been a remarkable progress. Clinical trials with fracture endpoints, already underway, should expand osteoanabolic therapeutic horizon in the very near future. Measurement of sclerostin levels in a number of conditions has advanced our knowledge about pathophysiology of skeletal and nonskeletal disorders in an altogether new light.
Collapse
Affiliation(s)
- Mahalakshmi Honasoge
- aDivision of Endocrinology, Diabetes, and Bone & Mineral Disorders, Henry Ford Hospital, Detroit, Michigan bSection of Endocrinology, Diabetes and Metabolism, Temple University School of Medicine, Philadelphia, Pennslyvania cBone and Mineral Research Laboratory, Henry Ford Hospital, Detroit, Michigan, USA
| | | | | |
Collapse
|
43
|
Abstract
Bone fragility is a major health concern, as the increased risk of bone fractures has devastating outcomes in terms of mortality, decreased autonomy, and healthcare costs. Efforts made to address this problem have considerably increased our knowledge about the mechanisms that regulate bone formation and resorption. In particular, we now have a much better understanding of the cellular events that are triggered when bones are mechanically stimulated and how these events can lead to improvements in bone mass. Despite these findings at the molecular level, most exercise intervention studies reveal either no effects or only minor benefits of exercise programs in improving bone mineral density (BMD) in osteoporotic patients. Nevertheless, and despite that BMD is the gold standard for diagnosing osteoporosis, this measure is only able to provide insights regarding the quantity of bone tissue. In this article, we review the complex structure of bone tissue and highlight the concept that its mechanical strength stems from the interaction of several different features. We revisited the available data showing that bone mineralization degree, hydroxyapatite crystal size and heterogeneity, collagen properties, osteocyte density, trabecular and cortical microarchitecture, as well as whole bone geometry, are determinants of bone strength and that each one of these properties may independently contribute to the increased or decreased risk of fracture, even without meaningful changes in aBMD. Based on these findings, we emphasize that while osteoporosis (almost) always causes bone fragility, bone fragility is not always caused just by osteoporosis, as other important variables also play a major role in this etiology. Furthermore, the results of several studies showing compelling data that physical exercise has the potential to improve bone quality and to decrease fracture risk by influencing each one of these determinants are also reviewed. These findings have meaningful clinical repercussions as they emphasize the fact that, even without leading to improvements in BMD, exercise interventions in patients with osteoporosis may be beneficial by improving other determinants of bone strength.
Collapse
|
44
|
Prideaux M, Wijenayaka AR, Kumarasinghe DD, Ormsby RT, Evdokiou A, Findlay DM, Atkins GJ. SaOS2 Osteosarcoma cells as an in vitro model for studying the transition of human osteoblasts to osteocytes. Calcif Tissue Int 2014; 95:183-93. [PMID: 24916279 DOI: 10.1007/s00223-014-9879-y] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Accepted: 05/21/2014] [Indexed: 12/18/2022]
Abstract
The central importance of osteocytes in regulating bone homeostasis is becoming increasingly apparent. However, the study of these cells has been restricted by the relative paucity of cell line models, especially those of human origin. Therefore, we investigated the extent to which SaOS2 human osteosarcoma cells can differentiate into osteocyte-like cells. During culture under the appropriate mineralising conditions, SaOS2 cells reproducibly synthesised a bone-like mineralised matrix and temporally expressed the mature osteocyte marker genes SOST, DMP1, PHEX and MEPE and down-regulated expression of RUNX2 and COL1A1. SaOS2 cells cultured in 3D collagen gels acquired a dendritic morphology, characteristic of osteocytes, with multiple interconnecting cell processes. These findings suggest that SaOS2 cells have the capacity to differentiate into mature osteocyte-like cells under mineralising conditions. PTH treatment of SaOS2 cells resulted in strong down-regulation of SOST mRNA expression at all time points tested. Interestingly, PTH treatment resulted in the up-regulation of RANKL mRNA expression only at earlier stages of differentiation. These findings suggest that the response to PTH is dependent on the differentiation stage of the osteoblast/osteocyte. Together, our results demonstrate that SaOS2 cells can be used as a human model to investigate responses to osteotropic stimuli throughout differentiation to a mature osteocyte-like stage.
Collapse
Affiliation(s)
- Matthew Prideaux
- Bone Cell Biology Group, Centre for Orthopaedic and Trauma Research, The University of Adelaide, North Terrace, Adelaide, SA, 5005, Australia
| | | | | | | | | | | | | |
Collapse
|
45
|
Synchrotron X-ray phase nano-tomography-based analysis of the lacunar–canalicular network morphology and its relation to the strains experienced by osteocytes in situ as predicted by case-specific finite element analysis. Biomech Model Mechanobiol 2014; 14:267-82. [DOI: 10.1007/s10237-014-0601-9] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Accepted: 06/06/2014] [Indexed: 11/26/2022]
|
46
|
HESSE BERNHARD, MÄNNICKE NILS, PACUREANU ALEXANDRA, VARGA PETER, LANGER MAX, MAURER PETER, PEYRIN FRANCOISE, RAUM KAY. Accessing osteocyte lacunar geometrical properties in human jaw bone on the submicron length scale using synchrotron radiation μCT. J Microsc 2014; 255:158-68. [DOI: 10.1111/jmi.12147] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Accepted: 05/14/2014] [Indexed: 11/28/2022]
Affiliation(s)
- BERNHARD HESSE
- Berlin-Brandenburg School for Regenerative Therapies and Julius Wolff Institut; Charité-Universitätsmedizin Berlin; Berlin Germany
- European Synchrotron Radiation Facility; Grenoble France
| | - NILS MÄNNICKE
- Berlin-Brandenburg School for Regenerative Therapies and Julius Wolff Institut; Charité-Universitätsmedizin Berlin; Berlin Germany
| | - ALEXANDRA PACUREANU
- European Synchrotron Radiation Facility; Grenoble France
- Université de Lyon, CREATIS; CNRS UMR 5220; Inserm U1044; INSA-Lyon; Université Lyon 1; Lyon France
- Centre for Image Analysis and Science for Life Laboratory; Uppsala University; Uppsala Sweden
| | - PETER VARGA
- Berlin-Brandenburg School for Regenerative Therapies and Julius Wolff Institut; Charité-Universitätsmedizin Berlin; Berlin Germany
| | - MAX LANGER
- European Synchrotron Radiation Facility; Grenoble France
- Centre for Image Analysis and Science for Life Laboratory; Uppsala University; Uppsala Sweden
| | - PETER MAURER
- Klinik für Mund-, Kiefer- und Gesichtschirurgie; Klinikum Bremerhaven-Reinkenheide; Bremerhaven; Germany
| | - FRANCOISE PEYRIN
- European Synchrotron Radiation Facility; Grenoble France
- Université de Lyon, CREATIS; CNRS UMR 5220; Inserm U1044; INSA-Lyon; Université Lyon 1; Lyon France
| | - KAY RAUM
- Berlin-Brandenburg School for Regenerative Therapies and Julius Wolff Institut; Charité-Universitätsmedizin Berlin; Berlin Germany
| |
Collapse
|
47
|
Bajaj D, Geissler JR, Allen MR, Burr DB, Fritton JC. The resistance of cortical bone tissue to failure under cyclic loading is reduced with alendronate. Bone 2014; 64:57-64. [PMID: 24704262 PMCID: PMC4041841 DOI: 10.1016/j.bone.2014.03.045] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2013] [Revised: 03/24/2014] [Accepted: 03/25/2014] [Indexed: 01/15/2023]
Abstract
Bisphosphonates are the most prescribed preventative treatment for osteoporosis. However, their long-term use has recently been associated with atypical fractures of cortical bone in patients who present with low-energy induced breaks of unclear pathophysiology. The effects of bisphosphonates on the mechanical properties of cortical bone have been exclusively studied under simple, monotonic, quasi-static loading. This study examined the cyclic fatigue properties of bisphosphonate-treated cortical bone at a level in which tissue damage initiates and is accumulated prior to frank fracture in low-energy situations. Physiologically relevant, dynamic, 4-point bending applied to beams (1.5 mm × 0.5 mm × 10 mm) machined from dog rib (n=12/group) demonstrated mechanical failure and micro-architectural features that were dependent on drug dose (3 groups: 0, 0.2, 1.0mg/kg/day; alendronate [ALN] for 3 years) with cortical bone tissue elastic modulus (initial cycles of loading) reduced by 21% (p<0.001) and fatigue life (number of cycles to failure) reduced in a stress-life approach by greater than 3-fold with ALN1.0 (p<0.05). While not affecting the number of osteons, ALN treatment reduced other features associated with bone remodeling, such as the size of osteons (-14%; ALN1.0: 10.5±1.8, VEH: 12.2±1.6, ×10(3) μm2; p<0.01) and the density of osteocyte lacunae (-20%; ALN1.0: 11.4±3.3, VEH: 14.3±3.6, ×10(2) #/mm2; p<0.05). Furthermore, the osteocyte lacunar density was directly proportional to initial elastic modulus when the groups were pooled (R=0.54, p<0.01). These findings suggest that the structural components normally contributing to healthy cortical bone tissue are altered by high-dose ALN treatment and contribute to reduced mechanical properties under cyclic loading conditions.
Collapse
Affiliation(s)
- Devendra Bajaj
- Department of Orthopaedics, New Jersey Medical School, Rutgers University, 205 S. Orange Avenue, Newark, NJ 07103, USA.
| | - Joseph R Geissler
- Department of Orthopaedics, New Jersey Medical School, Rutgers University, 205 S. Orange Avenue, Newark, NJ 07103, USA; Department of Biomedical Engineering, New Jersey Institute of Technology, 323 Martin Luther King, Jr. Boulevard, Newark, NJ 07102, USA.
| | - Matthew R Allen
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, 635 Barnhill Drive, Indianapolis, IN 46202, USA.
| | - David B Burr
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, 635 Barnhill Drive, Indianapolis, IN 46202, USA.
| | - J C Fritton
- Department of Orthopaedics, New Jersey Medical School, Rutgers University, 205 S. Orange Avenue, Newark, NJ 07103, USA; Department of Biomedical Engineering, New Jersey Institute of Technology, 323 Martin Luther King, Jr. Boulevard, Newark, NJ 07102, USA.
| |
Collapse
|
48
|
Soto SA, Chiappe Barbará A. Bisphosphonates: Pharmacology and Clinical Approach to Their Use in Equine Osteoarticular Diseases. J Equine Vet Sci 2014. [DOI: 10.1016/j.jevs.2014.01.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
|
49
|
Sato S, Hashimoto J, Usami Y, Ohyama K, Isogai Y, Hagiwara Y, Maruyama N, Komori T, Kuroda T, Toyosawa S. Novel sandwich ELISAs for rat DMP1: age-related decrease of circulatory DMP1 levels in male rats. Bone 2013; 57:429-36. [PMID: 24076023 DOI: 10.1016/j.bone.2013.09.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Revised: 09/14/2013] [Accepted: 09/20/2013] [Indexed: 12/17/2022]
Abstract
Dentin matrix protein 1 (DMP1), a noncollagenous bone matrix protein produced by osteocytes, regulates matrix mineralization and phosphate homeostasis. The lack of a precise assay for circulating DMP1 levels impairs further investigation of the protein's biological significance. Because full-length precursor DMP1 is cleaved into NH2- and COOH-terminal fragments during the secretory process, we developed two new sandwich ELISAs for the NH2- and COOH-terminal fragments of rat DMP1. One of these ELISAs, ELISA 1-2, is based on two affinity-purified polyclonal antibodies against the DMP1-1 and DMP1-2 peptides of the NH2-terminal fragment, whereas the other, ELISA 4-3, is based on two affinity-purified polyclonal antibodies against the DMP1-3 and DMP1-4 peptides of the COOH-terminal fragment. The polyclonal antibodies were characterized in immunohistochemical and liquid chromatography-electrospray ionization tandem mass spectrometry (LC-MS/MS) studies. Immunohistochemical analyses of rat bone using these polyclonal antibodies revealed DMP1 immunoreactivity in osteocytes and pericanalicular matrix, consistent with the previously reported osteocyte-specific expression of DMP1. LC-MS/MS analyses of rat plasma-derived immunoreactive products affinity-extracted with these antibodies revealed the presence of DMP1 in circulating blood. The ELISAs established with these antibodies met accepted standards for reproducibility, repeatability, precision, and accuracy. Circulating DMP1 and levels of other biochemical markers (osteocalcin, Trap5b, Dkk-1, and SOST) were measured in 2-, 4-, 8-, 12-, 18-, 24-, 72-, and 96-week-old Wistar male rats. Circulating DMP1 levels determined by ELISAs 1-2 and 4-3 significantly decreased with age. During rapid skeletal growth (2-12weeks), DMP1 levels measured by ELISA 4-3 were over three times higher than those measured by ELISA 1-2; however, DMP1 levels in old animals (72 and 96weeks) were almost the same when measured by either ELISA. DMP1 levels determined by both ELISAs were most highly positively correlated with the level of Dkk-1, second most highly correlated with the level of osteocalcin, and less highly correlated with the levels of Trap5b and SOST. These novel sandwich ELISAs for rat DMP1 are highly specific and allow precise measurements of circulating DMP1, which may be a new biochemical marker for osteocyte-mediated bone turnover.
Collapse
Affiliation(s)
- Sunao Sato
- Department of Oral Pathology, Graduate School of Dentistry, Osaka University, Osaka, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
50
|
Abstract
Mouse models with cell-specific deletion of the estrogen receptor (ER) α, the androgen receptor (AR) or the receptor activator of nuclear factor κB ligand (RANKL), as well as cascade-selective estrogenic compounds have provided novel insights into the function and signalling of ERα and AR. The studies reveal that the effects of estrogens on trabecular versus cortical bone mass are mediated by direct effects on osteoclasts and osteoblasts, respectively. The protection of cortical bone mass by estrogens is mediated via ERα, using a non-nucleus-initiated mechanism. By contrast, the AR of mature osteoblasts is indispensable for the maintenance of trabecular bone mass in male mammals, but not required for the anabolic effects of androgens on cortical bone. Most unexpectedly, and independently of estrogens, ERα in osteoblast progenitors stimulates Wnt signalling and periosteal bone accrual in response to mechanical strain. RANKL expression in B lymphocytes, but not T lymphocytes, contributes to the loss of trabecular bone caused by estrogen deficiency. In this Review, we summarize this evidence and discuss its implications for understanding the regulation of trabecular and cortical bone mass; the integration of hormonal and mechanical signals; the relative importance of estrogens versus androgens in the male skeleton; and, finally, the pathogenesis and treatment of osteoporosis.
Collapse
Affiliation(s)
- Stavros C Manolagas
- Division of Endocrinology and Metabolism, Centre for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences and the Central Arkansas Veterans Healthcare System, 4301 West Markham, Little Rock, AR 72205-7199, USA
| | - Charles A O'Brien
- Division of Endocrinology and Metabolism, Centre for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences and the Central Arkansas Veterans Healthcare System, 4301 West Markham, Little Rock, AR 72205-7199, USA
| | - Maria Almeida
- Division of Endocrinology and Metabolism, Centre for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences and the Central Arkansas Veterans Healthcare System, 4301 West Markham, Little Rock, AR 72205-7199, USA
| |
Collapse
|