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Liu Z, Gao J, Gong H. Spatiotemporal Characterization of Microstructure Morphology, Mechanical Properties and Bone Remodeling of Rat Tibia Under Uniaxial Compressive Overload Loading. Ann Biomed Eng 2024; 52:2388-2402. [PMID: 38744754 DOI: 10.1007/s10439-024-03531-y] [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: 11/08/2023] [Accepted: 04/30/2024] [Indexed: 05/16/2024]
Abstract
Bone tissue is subjected to increased mechanical stress during high-intensity work. Inadequate bone remodeling reparability can result in the continuous accumulation of microdamage, leading to stress fractures. The aim of this work was to investigate the characteristics and repair mechanisms of tibial microdamage under several degrees of overload. Also, we aimed at better understanding the effects of overload on the multi-scale structure and mechanical properties of bone. Sixty 5-month female rats were divided into three groups with different time points. Micro-CT was used to evaluate the three-dimensional microstructure, and three-point bending, quasi-static fracture toughness and creep mechanical test were carried out to evaluate the mechanical properties. SEM was used to observe the morphological characteristics of fracture surfaces. Section staining was used to count the microdamage parameters and numbers of osteoblasts and osteoclasts. The microarchitectures of cancellous and cortical bones in the three overload groups showed different degrees of damage. Overload led to a messy crystal structure of cortical bone, with slender microcracks mixed in, and a large number of broken fibers of cancellous bone. The properties associated with the elastic plasticity, fracture toughness, and viscoelasticity of cortical bone reduced in three groups, with that corresponding to day 30 presenting the highest damage. The accumulation of microdamage mainly occurred in the first 14 days, that is, the crack density peaked on day 14. Peak-targeted bone remodeling of cortical and cancellous bones occurred mainly between days 14 and 30. The influence of overload mechanical environment on bone quality at different time points was deeply investigated, which is of great significance for the etiology and treatment of stress fractures.
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Affiliation(s)
- Zhehao Liu
- Department of Biotechnology, College of Basic Medical Sciences, Dalian Medical University, Dalian, 116044, People's Republic of China
- Department of Engineering Mechanics, College of Mechanical and Aerospace Engineering, Jilin University, Changchun, 130022, People's Republic of China
| | - Jiazi Gao
- Department of Engineering Mechanics, College of Mechanical and Aerospace Engineering, Jilin University, Changchun, 130022, People's Republic of China
| | - He Gong
- School of Biological Science and Medical Engineering, Beihang University, Beijing, 100191, People's Republic of China.
- Department of Engineering Mechanics, College of Mechanical and Aerospace Engineering, Jilin University, Changchun, 130022, People's Republic of China.
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Ding Y, Yang Y, Xu F, Tan Z, Liu X, Shao X, Kang F, Yan Z, Luo E, Wang J, Luo Z, Cai J, Jing D. Early protection against bone stress injuries by mobilization of endogenous targeted bone remodeling. iScience 2023; 26:107605. [PMID: 37664634 PMCID: PMC10470328 DOI: 10.1016/j.isci.2023.107605] [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: 03/07/2023] [Revised: 06/29/2023] [Accepted: 08/08/2023] [Indexed: 09/05/2023] Open
Abstract
Bone stress injuries are common overuse injuries, especially in soldiers, athletes, and performers. In contrast to various post-injury treatments, early protection against bone stress injuries can provide greater benefit. This study explored the early protection strategies against bone stress injuries by mobilization of endogenous targeted bone remodeling. The effects of various pharmaceutical/biophysical approaches, individual or combinational, were investigated by giving intervention before fatigue loading. We optimized the dosage and administration parameters and found that early intervention with pulsed electromagnetic field and parathyroid hormone (i.e., PEMF+PTH) resulted in the most pronounced protective effects among all the approaches against the bone stress injuries. In addition, the mechanisms by which the strategy mobilizes targeted bone remodeling and enhances the self-repair capacity of bone were systematically investigated. This study proposes strategies to reduce the incidence of bone stress injuries in high-risk populations (e.g., soldiers and athletes), particularly for those before sudden increased physical training.
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Affiliation(s)
- Yuanjun Ding
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
| | - Yongqing Yang
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
| | - Fei Xu
- Department of Radiation Oncology, Peking University Third Hospital, Beijing, China
| | - Zhifen Tan
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
| | - Xiyu Liu
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
| | - Xi Shao
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
| | - Fei Kang
- Department of Nuclear Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Zedong Yan
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
| | - Erping Luo
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
| | - Jing Wang
- Department of Nuclear Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Zhuojing Luo
- Institute of Orthopaedics, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Jing Cai
- College of Basic Medicine, Shaanxi University of Chinese Medicine, Xianyang, China
| | - Da Jing
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
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Liu X, Yan Z, Cai J, Wang D, Yang Y, Ding Y, Shao X, Hao X, Luo E, Guo XE, Luo P, Shen L, Jing D. Glucose- and glutamine-dependent bioenergetics sensitize bone mechanoresponse after unloading by modulating osteocyte calcium dynamics. J Clin Invest 2023; 133:164508. [PMID: 36512405 PMCID: PMC9888392 DOI: 10.1172/jci164508] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 12/08/2022] [Indexed: 12/15/2022] Open
Abstract
Disuse osteoporosis is a metabolic bone disease resulting from skeletal unloading (e.g., during extended bed rest, limb immobilization, and spaceflight), and the slow and insufficient bone recovery during reambulation remains an unresolved medical challenge. Here, we demonstrated that loading-induced increase in bone architecture/strength was suppressed in skeletons previously exposed to unloading. This reduction in bone mechanosensitivity was directly associated with attenuated osteocytic Ca2+ oscillatory dynamics. The unloading-induced compromised osteocytic Ca2+ response to reloading resulted from the HIF-1α/PDK1 axis-mediated increase in glycolysis, and a subsequent reduction in ATP synthesis. HIF-1α also transcriptionally induced substantial glutaminase 2 expression and thereby glutamine addiction in osteocytes. Inhibition of glycolysis by blockade of PDK1 or glutamine supplementation restored the mechanosensitivity in those skeletons with previous unloading by fueling the tricarboxylic acid cycle and rescuing subsequent Ca2+ oscillations in osteocytes. Thus, we provide mechanistic insight into disuse-induced deterioration of bone mechanosensitivity and a promising therapeutic approach to accelerate bone recovery after long-duration disuse.
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Affiliation(s)
- Xiyu Liu
- Department of Biomedical Engineering, Fourth Military Medical University, Xi’an, China
| | - Zedong Yan
- Department of Biomedical Engineering, Fourth Military Medical University, Xi’an, China
| | - Jing Cai
- College of Basic Medicine, Shaanxi University of Chinese Medicine, Xianyang, China
| | - Dan Wang
- Department of Biomedical Engineering, Fourth Military Medical University, Xi’an, China
| | - Yongqing Yang
- Department of Biomedical Engineering, Fourth Military Medical University, Xi’an, China
| | - Yuanjun Ding
- Department of Biomedical Engineering, Fourth Military Medical University, Xi’an, China
| | - Xi Shao
- Department of Biomedical Engineering, Fourth Military Medical University, Xi’an, China
| | - Xiaoxia Hao
- Department of Biomedical Engineering, Fourth Military Medical University, Xi’an, China
| | - Erping Luo
- Department of Biomedical Engineering, Fourth Military Medical University, Xi’an, China
| | - X. Edward Guo
- Bone Bioengineering Laboratory, Department of Biomedical Engineering, Columbia University, New York, New York, USA
| | - Peng Luo
- Department of Neurosurgery, Xijing Hospital
| | - Liangliang Shen
- State Key Laboratory of Cancer Biology, Department of Biochemistry and Molecular Biology
| | - Da Jing
- Department of Biomedical Engineering, Fourth Military Medical University, Xi’an, China.,Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, and,Shaanxi Provincial Key Laboratory of Bioelectromagnetic Detection and Intelligent Perception, Fourth Military Medical University, Xi’an, China
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Osteocyte apoptosis: the roles and key molecular mechanisms in resorption-related bone diseases. Cell Death Dis 2020; 11:846. [PMID: 33046704 PMCID: PMC7552426 DOI: 10.1038/s41419-020-03059-8] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Revised: 09/23/2020] [Accepted: 09/24/2020] [Indexed: 01/18/2023]
Abstract
Vital osteocytes have been well known to function as an important orchestrator in the preservation of robustness and fidelity of the bone remodeling process. Nevertheless, some key pathological factors, such as sex steroid deficiency and excess glucocorticoids, and so on, are implicated in inducing a bulk of apoptotic osteocytes, subsequently resulting in resorption-related bone loss. As much, osteocyte apoptosis, under homeostatic conditions, is in an optimal state of balance tightly controlled by pro- and anti-apoptotic mechanism pathways. Importantly, there exist many essential signaling proteins in the process of osteocyte apoptosis, which has a crucial role in maintaining a homeostatic environment. While increasing in vitro and in vivo studies have established, in part, key signaling pathways and cross-talk mechanism on osteocyte apoptosis, intrinsic and complex mechanism underlying osteocyte apoptosis occurs in various states of pathologies remains ill-defined. In this review, we discuss not only essential pro- and anti-apoptotic signaling pathways and key biomarkers involved in these key mechanisms under different pathological agents, but also the pivotal role of apoptotic osteocytes in osteoclastogenesis-triggered bone loss, hopefully shedding new light on the attractive and proper actions of pharmacotherapeutics of targeting apoptosis and ensuing resorption-related bone diseases such as osteoporosis and fragility fractures.
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