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Pivonka P, Calvo-Gallego JL, Schmidt S, Martínez-Reina J. Advances in mechanobiological pharmacokinetic-pharmacodynamic models of osteoporosis treatment - Pathways to optimise and exploit existing therapies. Bone 2024; 186:117140. [PMID: 38838799 DOI: 10.1016/j.bone.2024.117140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Revised: 05/17/2024] [Accepted: 05/29/2024] [Indexed: 06/07/2024]
Abstract
Osteoporosis (OP) is a chronic progressive bone disease which is characterised by reduction of bone matrix volume and changes in the bone matrix properties which can ultimately lead to bone fracture. The two major forms of OP are related to aging and/or menopause. With the worldwide increase of the elderly population, particularly age-related OP poses a serious health issue which puts large pressure on health care systems. A major challenge for development of new drug treatments for OP and comparison of drug efficacy with existing treatments is due to current regulatory requirements which demand testing of drugs based on bone mineral density (BMD) in phase 2 trials and fracture risk in phase 3 trials. This requires large clinical trials to be conducted and to be run for long time periods, which is very costly. This, together with the fact that there are already many drugs available for treatment of OP, makes the development of new drugs inhibitive. Furthermore, an increased trend of the use of different sequential drug therapies has been observed in OP management, such as sequential anabolic-anticatabolic drug treatment or switching from one anticatabolic drug to another. Running clinical trials for concurrent and sequential therapies is neither feasible nor practical due to large number of combinatorial possibilities. In silico mechanobiological pharmacokinetic-pharmacodynamic (PK-PD) models of OP treatments allow predictions beyond BMD, i.e. bone microdamage and degree of mineralisation can also be monitored. This will help to inform clinical drug usage and development by identifying the most promising scenarios to be tested clinically (confirmatory trials rather than exploratory only trials), optimise trial design and identify subgroups of the population that show benefit-risk profiles (both good and bad) that are different from the average patient. In this review, we provide examples of the predictive capabilities of mechanobiological PK-PD models. These include simulation results of PMO treatment with denosumab, implications of denosumab drug holidays and coupling of bone remodelling models with calcium and phosphate systems models that allows to investigate the effects of co-morbidities such as hyperparathyroidism and chronic kidney disease together with calcium and vitamin D status on drug efficacy.
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Affiliation(s)
- Peter Pivonka
- School of Mechanical, Medical and Process Engineering, Queensland University of Technology, QLD 4000, Australia.
| | - José Luis Calvo-Gallego
- Departmento de Ingeniería Mecánica y Fabricación, Universidad de Sevilla, Seville 41092, Spain
| | - Stephan Schmidt
- Center for Pharmacometrics and Systems Pharmacology, Department of Pharmaceutics, College of Pharmacy, University of Florida, Orlando, FL 32827, USA
| | - Javier Martínez-Reina
- Departmento de Ingeniería Mecánica y Fabricación, Universidad de Sevilla, Seville 41092, Spain
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Marino S, Bellido T. PTH receptor signalling, osteocytes and bone disease induced by diabetes mellitus. Nat Rev Endocrinol 2024:10.1038/s41574-024-01014-7. [PMID: 39020007 DOI: 10.1038/s41574-024-01014-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/17/2024] [Indexed: 07/19/2024]
Abstract
Basic, translational and clinical research over the past few decades has provided new understanding on the mechanisms by which activation of the receptor of parathyroid hormone (parathyroid hormone 1 receptor (PTH1R)) regulates bone physiology and pathophysiology. A fundamental change in the field emerged upon the recognition that osteocytes, which are permanent residents of bone and the most abundant cells in bone, are targets of the actions of natural and synthetic ligands of PTH1R (parathyroid hormone and abaloparatide, respectively), and that these cells drive essential actions related to bone remodelling. Among the numerous genes regulated by PTH1R in osteocytes, SOST (which encodes sclerostin, the WNT signalling antagonist and inhibitor of bone formation) has a critical role in bone homeostasis and changes in its expression are associated with several bone pathologies. The bone fragility syndrome induced by diabetes mellitus is accompanied by increased osteocyte apoptosis and changes in the expression of osteocytic genes, including SOST. This Review will discuss advances in our knowledge of the role of osteocytes in PTH1R signalling and the new opportunities to restore bone health in diabetes mellitus by targeting the osteocytic PTH1R-sclerostin axis.
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Affiliation(s)
- Silvia Marino
- Department of Physiology and Cell Biology, University of Arkansas for Medical Sciences, Little Rock, AR, USA
- Central Arkansas Veterans Healthcare System, John L. McClellan Little Rock, Little Rock, AR, USA
| | - Teresita Bellido
- Department of Physiology and Cell Biology, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
- Central Arkansas Veterans Healthcare System, John L. McClellan Little Rock, Little Rock, AR, USA.
- Winthrop P. Rockefeller Cancer Institute, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
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Creecy A, Segvich D, Metzger C, Kohler R, Wallace JM. Combining anabolic loading and raloxifene improves bone quantity and some quality measures in a mouse model of osteogenesis imperfecta. Bone 2024; 184:117106. [PMID: 38641232 PMCID: PMC11130993 DOI: 10.1016/j.bone.2024.117106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Revised: 03/20/2024] [Accepted: 04/15/2024] [Indexed: 04/21/2024]
Abstract
Osteogenesis imperfecta (OI) increases fracture risk due to changes in bone quantity and quality caused by mutations in collagen and its processing proteins. Current therapeutics improve bone quantity, but do not treat the underlying quality deficiencies. Male and female G610C+/- mice, a murine model of OI, were treated with a combination of raloxifene and in vivo axial tibial compressive loading starting at 10 weeks of age and continuing for 6 weeks to improve bone quantity and quality. Bone geometry and mechanical properties were measured to determine whole bone and tissue-level material properties. A colocalized Raman/nanoindentation system was used to measure chemical composition and nanomechanical properties in newly formed bone compared to old bone to determine if bone formed during the treatment regimen differed in quality compared to bone formed prior to treatment. Lastly, lacunar geometry and osteocyte apoptosis were assessed. OI mice were able to build bone in response to the loading, but this response was less robust than in control mice. Raloxifene improved some bone material properties in female but not male OI mice. Raloxifene did not alter nanomechanical properties, but loading did. Lacunar geometry was largely unchanged with raloxifene and loading. However, osteocyte apoptosis was increased with loading in raloxifene treated female mice. Overall, combination treatment with raloxifene and loading resulted in positive but subtle changes to bone quality.
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Affiliation(s)
- Amy Creecy
- Department of Biomedical Engineering, Indiana University Purdue University Indianapolis, United States of America.
| | - Dyann Segvich
- Department of Biomedical Engineering, Indiana University Purdue University Indianapolis, United States of America
| | - Corinne Metzger
- Department of Anatomy, Cell Biology, and Physiology, Indiana University School of Medicine, Indianapolis, IN, United States of America
| | - Rachel Kohler
- Department of Biomedical Engineering, Indiana University Purdue University Indianapolis, United States of America
| | - Joseph M Wallace
- Department of Biomedical Engineering, Indiana University Purdue University Indianapolis, United States of America
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Yin Y, Chen GJ, Yang C, Wang JJ, Peng JF, Huang XF, Tang QM, Chen LL. Osteocyte ferroptosis induced by ATF3/TFR1 contributes to cortical bone loss during ageing. Cell Prolif 2024:e13657. [PMID: 38764128 DOI: 10.1111/cpr.13657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 04/20/2024] [Accepted: 05/03/2024] [Indexed: 05/21/2024] Open
Abstract
Cortical bone loss is intricately associated with ageing and coincides with iron accumulation. The precise role of ferroptosis, characterized by iron overload and lipid peroxidation, in senescent osteocytes remains elusive. We found that ferroptosis was a crucial mode of osteocyte death in cortical bone during ageing. Using a single-cell transcriptome analysis, we identified activating transcription factor 3 (ATF3) as a critical driver of osteocyte ferroptosis. Elevated ATF3 expression in senescent osteocytes promotes iron uptake by upregulating transferrin receptor 1 while simultaneously inhibiting solute carrier family 7-member 11-mediated cystine import. This process leads to an iron overload and lipid peroxidation, culminating in ferroptosis. Importantly, ATF3 inhibition in aged mice effectively alleviated ferroptosis in the cortical bone and mitigated cortical bone mass loss. Taken together, our findings establish a pivotal role of ferroptosis in cortical bone loss in older adults, providing promising prevention and treatment strategies for osteoporosis and fractures.
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Affiliation(s)
- Ying Yin
- Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- School of Stomatology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- Hubei Province Key Laboratory of Oral and Maxillofacial Development and Regeneration, Wuhan, China
| | - Guang-Jin Chen
- Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- School of Stomatology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- Hubei Province Key Laboratory of Oral and Maxillofacial Development and Regeneration, Wuhan, China
| | - Chen Yang
- Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- School of Stomatology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- Hubei Province Key Laboratory of Oral and Maxillofacial Development and Regeneration, Wuhan, China
| | - Jia-Jia Wang
- Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- School of Stomatology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- Hubei Province Key Laboratory of Oral and Maxillofacial Development and Regeneration, Wuhan, China
| | - Jin-Feng Peng
- Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- School of Stomatology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- Hubei Province Key Laboratory of Oral and Maxillofacial Development and Regeneration, Wuhan, China
| | - Xiao-Fei Huang
- Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- School of Stomatology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- Hubei Province Key Laboratory of Oral and Maxillofacial Development and Regeneration, Wuhan, China
| | - Qing-Ming Tang
- Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- School of Stomatology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- Hubei Province Key Laboratory of Oral and Maxillofacial Development and Regeneration, Wuhan, China
| | - Li-Li Chen
- Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- School of Stomatology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- Hubei Province Key Laboratory of Oral and Maxillofacial Development and Regeneration, Wuhan, China
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Luo Y, Zheng S, Xiao W, Zhang H, Li Y. Pannexins in the musculoskeletal system: new targets for development and disease progression. Bone Res 2024; 12:26. [PMID: 38705887 PMCID: PMC11070431 DOI: 10.1038/s41413-024-00334-8] [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: 12/08/2023] [Revised: 03/04/2024] [Accepted: 04/01/2024] [Indexed: 05/07/2024] Open
Abstract
During cell differentiation, growth, and development, cells can respond to extracellular stimuli through communication channels. Pannexin (Panx) family and connexin (Cx) family are two important types of channel-forming proteins. Panx family contains three members (Panx1-3) and is expressed widely in bone, cartilage and muscle. Although there is no sequence homology between Panx family and Cx family, they exhibit similar configurations and functions. Similar to Cxs, the key roles of Panxs in the maintenance of physiological functions of the musculoskeletal system and disease progression were gradually revealed later. Here, we seek to elucidate the structure of Panxs and their roles in regulating processes such as osteogenesis, chondrogenesis, and muscle growth. We also focus on the comparison between Cx and Panx. As a new key target, Panxs expression imbalance and dysfunction in muscle and the therapeutic potentials of Panxs in joint diseases are also discussed.
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Affiliation(s)
- Yan Luo
- Department of Orthopedics, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
- Department of Clinical Medicine, Xiangya Medicine School, Central South University, Changsha, Hunan, 410008, China
| | - Shengyuan Zheng
- Department of Orthopedics, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
- Department of Clinical Medicine, Xiangya Medicine School, Central South University, Changsha, Hunan, 410008, China
| | - Wenfeng Xiao
- Department of Orthopedics, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
| | - Hang Zhang
- Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China.
| | - Yusheng Li
- Department of Orthopedics, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China.
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China.
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Muratovic D, Atkins GJ, Findlay DM. Is RANKL a potential molecular target in osteoarthritis? Osteoarthritis Cartilage 2024; 32:493-500. [PMID: 38160744 DOI: 10.1016/j.joca.2023.10.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 10/09/2023] [Accepted: 10/27/2023] [Indexed: 01/03/2024]
Abstract
OBJECTIVE Osteoarthritis (OA) is a disease of joints, in which the bone under the articular cartilage undergoes increased remodelling activity. The question is whether a better understanding of the causes and mechanisms of bone remodelling can predict disease-modifying treatments. DESIGN This review summarises the current understanding of the aetiology of OA, with an emphasis on events in the subchondral bone (SCB), and the cells and cytokines involved, to seek an answer to this question. RESULTS SCB remodelling across OA changes the microstructure of the SCB, which alters the load-bearing properties of the joint and seems to have an important role in the initiation and progression of OA. Bone remodelling is tightly controlled by numerous cytokines, of which Receptor Activator of NFκB ligand (RANKL) and osteoprotegerin are central factors in almost all known bone conditions. In terms of finding therapeutic options for OA, an important question is whether controlling the rate of SCB remodelling would be beneficial. The role of RANKL in the pathogenesis and progression of OA and the effect of its neutralisation remain to be clarified. CONCLUSIONS This review further makes the case for SCB remodelling as important in OA and for additional study of RANKL in OA, both its pathophysiological role and its potential as an OA disease target.
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Affiliation(s)
- Dzenita Muratovic
- Centre for Orthopaedic & Trauma Research, The University of Adelaide, Adelaide, South Australia 5000, Australia; Biomedical Orthopaedic Research Group, Centre for Orthopaedic & Trauma Research, The University of Adelaide, Adelaide, South Australia 5000, Australia.
| | - Gerald J Atkins
- Centre for Orthopaedic & Trauma Research, The University of Adelaide, Adelaide, South Australia 5000, Australia; Biomedical Orthopaedic Research Group, Centre for Orthopaedic & Trauma Research, The University of Adelaide, Adelaide, South Australia 5000, Australia.
| | - David M Findlay
- Centre for Orthopaedic & Trauma Research, The University of Adelaide, Adelaide, South Australia 5000, Australia.
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Emam SM, Moussa N. Signaling pathways of dental implants' osseointegration: a narrative review on two of the most relevant; NF-κB and Wnt pathways. BDJ Open 2024; 10:29. [PMID: 38580623 PMCID: PMC10997788 DOI: 10.1038/s41405-024-00211-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Revised: 03/09/2024] [Accepted: 03/11/2024] [Indexed: 04/07/2024] Open
Abstract
INTRODUCTION Cell signaling pathways are the biological reactions that control cell functions and fate. They also directly affect the body reactions to implanted biomaterials. It is well-known that dental implants success depends on a successful integration with the alveolar bone: "osseointegration" which events comprise early and later responses to the implanted biomaterials. The early events are mainly immune-inflammatory responses to the implant considered by its microenvironment as a foreign body. Later reactions are osteogenic aiming to regulate bone formation and remodeling. All these events are controlled by the cell signaling pathways in an incredible harmonious coordination. AIM The number of pathways having a role in osseointegration is so big to be reviewed in a single article. So the aim of this review was to study only two of the most relevant ones: the inflammatory Nuclear Factor Kappa B (NF-κB) pathway regulating the early osseointegration events and the osteogenic Wnt pathway regulating later events. METHODS We conducted a literature review using key databases to provide an overview about the NF-κB and Wnt cell signaling pathways and their mutual relationship with dental implants. A simplified narrative approach was conducted to explain these cell signaling pathways, their mode of activation and how they are related to the cellular events of osseointegration. RESULTS AND CONCLUSION NF-κB and Wnt cell signaling pathways are important cross-talking pathways that are affected by the implant's material and surface characteristics. The presence of the implant itself in the bone alters the intracellular events of both pathways in the adjacent implant's cellular microenvironment. Both pathways have a great role in the success or failure of osseointegration. Such knowledge can offer a new hope to treat failed implants and enhance osseointegration in difficult cases. This is consistent with advances in Omics technologies that can change the paradigm of dental implant therapy.
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Affiliation(s)
- Samar Mohamed Emam
- Department of Prosthodontics, Faculty of Dentistry, Alexandria University, Alexandria, Egypt.
- Department of Biotechnology, Institute of Graduate Studies and Research, Alexandria University, Alexandria, Egypt.
| | - Nermine Moussa
- Department of Biotechnology, Institute of Graduate Studies and Research, Alexandria University, Alexandria, Egypt
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Fernandes Da Costa C, Attik N, Gauthier R. Influence of intramedullary pressure on Lacuno-Canalicular fluid flow: A systematic review. Acta Biomater 2024; 178:41-49. [PMID: 38484832 DOI: 10.1016/j.actbio.2024.03.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 03/01/2024] [Accepted: 03/06/2024] [Indexed: 03/24/2024]
Abstract
While most of current models investigating bone remodelling are based on matrix deformation, intramedullary pressure also plays a role. Bone remodelling is orchestrated by the Lacuno-Canalicular Network (LCN) fluid-flow. The aim of this review was hence to assess the influence of intramedullary pressure on the fluid circulation within the LCN. Three databases (Science Direct, Web of Science, and PubMed) were used. The first phase of the search returned 731 articles, of which 9 respected the inclusion/exclusion criteria and were included. These studies confirm the association between intramedullary pressure and fluid dynamics in the LCN. Among the included studies, 7 experimental studies using animal models and 2 numerical models were found. The studies were then ranked according to the nature of the applied loading, either axial compression or direct cyclic intramedullary pressure. The current review revealed that there is an influence of intramedullary pressure on LCN fluid dynamics and that this influence depends on the magnitude and the frequency of the applied pressure. Two studies confirmed that the influence was effective even without bone matrix deformation. While intramedullary pressure is closely associated with LCN fluid, there is a severe lack of studies on this topic. STATEMENT OF SIGNIFICANCE: Since the 1990's, numerical models developed to investigate fluid flow in bone submicrometric porous network are based on the flow induced by matrix deformation. Bone fluid flow is known to be involved in cells stimulation and hence directly influences bone remodeling. Different studies have shown that intramedullary pressure is also associated with bone mechanosensitive adaptation. This pressure is developed in bone due to blood circulation and is increased during loading or muscle stimulation. The current article reviews the studies investigating the influence of this pressure on bone porous fluid flow. They show that fluid flow is involved by this pressure even without bone matrix deformation. The current review article highlights the severe lack of studies about this mechanism.
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Affiliation(s)
- Cassandra Fernandes Da Costa
- UMR CNRS 5615, Laboratoire des Multimatériaux et Interfaces, Université de Lyon, Université Claude Bernard Lyon 1, Lyon 69372 CEDEX 08, France; CNRS, INSA Lyon, MATEIS, UMR5510, Université de Lyon, Université Claude Bernard Lyon 1, 7 avenue Jean Capelle, Villeurbanne CEDEX 69621, France
| | - Nina Attik
- UMR CNRS 5615, Laboratoire des Multimatériaux et Interfaces, Université de Lyon, Université Claude Bernard Lyon 1, Lyon 69372 CEDEX 08, France; Faculté d'Odontologie, Université de Lyon, Université Claude Bernard Lyon 1, Lyon 69372 CEDEX 08, France.
| | - Remy Gauthier
- CNRS, INSA Lyon, MATEIS, UMR5510, Université de Lyon, Université Claude Bernard Lyon 1, 7 avenue Jean Capelle, Villeurbanne CEDEX 69621, France.
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Wang P, Wang X, Qian H, Liu J, Liu G, Wang R, Liu R. Microarchitecture Alternations of Osteochondral Junction in Patients with Osteonecrosis of the Femoral Head. Calcif Tissue Int 2024; 114:119-128. [PMID: 38036697 DOI: 10.1007/s00223-023-01153-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2023] [Accepted: 10/06/2023] [Indexed: 12/02/2023]
Abstract
The study was aimed to investigate microarchitecture of osteochondral junction in patients with osteonecrosis of the femoral head (ONFH). We hypothesis that there were microarchitecture alternations in osteochondral junction and regional differences between the necrotic region (NR) and adjacent non-necrotic region(ANR) in patients with ONFH. Femoral heads with ONFH or femoral neck fracture were included in ONFH group (n = 11) and control group (n = 11). Cylindrical specimens were drilled on the NR/ANR of femoral heads in ONFH group and matched positions in control group (CO.NR/ CO.ANR). Histology, micro-CT, and scanning electron microscope were used to investigate microarchitecture of osteochondral junction. Layered analysis of subchondral bone plate was underwent. Mankin scores on NR were higher than that on ANR or CO.NR, respectively (P < 0.001, P < 0.001). Calcified cartilage zone on the NR and ANR was thinner than that on the CO.NR and CO.ANR, respectively (P = 0.002, P = 0.002). Tidemark roughness on the NR was larger than that on the ANR (P = 0.002). Subchondral bone plate of NR and ANR was thicker than that on the CON.NR and CON.ANR, respectively (P = 0.002, P = 0.009). Bone volume fraction of subchondral bone plate on the NR was significantly decreasing compared to ANR and CON.NR, respectively (P = 0.015, P = 0.002). Subchondral bone plate on the NR had larger area percentages and more numbers of micropores than ANR and CON.NR (P = 0.002/0.002, P = 0.002/0.002). Layered analysis showed that bone mass loss and hypomineralization were mainly on the cartilage side of subchondral bone plate in ONFH. There were microarchitecture alternations of osteochondral junction in ONFH, including thinned calcified cartilage zone, thickened subchondral bone plate, decreased bone mass, altered micropores, and hypomineralization of subchondral bone plate. Regional differences in microarchitecture of osteochondral junction were found between necrotic regions and adjacent non-necrotic regions. Subchondral bone plate in ONFH had uneven distribution of bone volume fraction and bone mineral density, which might aggravate cartilage degeneration by affecting the transmission of mechanical stresses.
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Affiliation(s)
- Pengbo Wang
- Department of Orthopedics, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Xu Wang
- Department of Orthopedics, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Hang Qian
- Department of Orthopedics, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Jun Liu
- Department of Orthopedics, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Gang Liu
- Department of Orthopedics, Xi'an Daxing Hospital, Xi'an, 710000, China
| | - Ruisong Wang
- Department of Orthopedics, Xi'an Fifth Hospital, Xi'an, 710000, China
| | - Ruiyu Liu
- Department of Orthopedics, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an Jiaotong University, Xi'an, 710049, China.
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Yao C, Sun J, Luo W, Chen H, Chen T, Chen C, Zhang B, Zhang Y. Down-expression of miR-494-3p in senescent osteocyte-derived exosomes inhibits osteogenesis and accelerates age-related bone loss via PTEN/PI3K/AKT pathway. Bone Joint Res 2024; 13:52-65. [PMID: 38295830 PMCID: PMC10830172 DOI: 10.1302/2046-3758.132.bjr-2023-0146.r2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2024] Open
Abstract
Aims To investigate the effects of senescent osteocytes on bone homeostasis in the progress of age-related osteoporosis and explore the underlying mechanism. Methods In a series of in vitro experiments, we used tert-Butyl hydroperoxide (TBHP) to induce senescence of MLO-Y4 cells successfully, and collected conditioned medium (CM) and senescent MLO-Y4 cell-derived exosomes, which were then applied to MC3T3-E1 cells, separately, to evaluate their effects on osteogenic differentiation. Furthermore, we identified differentially expressed microRNAs (miRNAs) between exosomes from senescent and normal MLO-Y4 cells by high-throughput RNA sequencing. Based on the key miRNAs that were discovered, the underlying mechanism by which senescent osteocytes regulate osteogenic differentiation was explored. Lastly, in the in vivo experiments, the effects of senescent MLO-Y4 cell-derived exosomes on age-related bone loss were evaluated in male SAMP6 mice, which excluded the effects of oestrogen, and the underlying mechanism was confirmed. Results The CM and exosomes collected from senescent MLO-Y4 cells inhibited osteogenic differentiation of MC3T3-E1 cells. RNA sequencing detected significantly lower expression of miR-494-3p in senescent MLO-Y4 cell-derived exosomes compared with normal exosomes. The upregulation of exosomal miR-494-3p by miRNA mimics attenuated the effects of senescent MLO-Y4 cell-derived exosomes on osteogenic differentiation. Luciferase reporter assay demonstrated that miR-494-3p targeted phosphatase and tensin homolog (PTEN), which is a negative regulator of the phosphoinositide 3-kinase (PI3K)/AKT pathway. Overexpression of PTEN or inhibition of the PI3K/AKT pathway blocked the functions of exosomal miR-494-3p. In SAMP6 mice, senescent MLO-Y4 cell-derived exosomes accelerated bone loss, which was rescued by upregulation of exosomal miR-494-3p. Conclusion Reduced expression of miR-494-3p in senescent osteocyte-derived exosomes inhibits osteogenic differentiation and accelerates age-related bone loss via PTEN/PI3K/AKT pathway.
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Affiliation(s)
- Chen Yao
- Department of Orthopaedics, Affiliated Hospital of Nantong University, Medical School of Nantong University, Nantong, Jiangsu, China
| | - Jie Sun
- Department of Orthopaedics, Affiliated Hospital of Nantong University, Medical School of Nantong University, Nantong, Jiangsu, China
| | - Wanxin Luo
- Department of Orthopaedics, Affiliated Hospital of Nantong University, Medical School of Nantong University, Nantong, Jiangsu, China
| | - Hao Chen
- Department of Orthopaedics, Affiliated Hospital of Nantong University, Medical School of Nantong University, Nantong, Jiangsu, China
| | - Tianhao Chen
- Department of Orthopaedics, Affiliated Hospital of Nantong University, Medical School of Nantong University, Nantong, Jiangsu, China
| | - Cao Chen
- Department of Orthopaedics, Affiliated Hospital of Nantong University, Medical School of Nantong University, Nantong, Jiangsu, China
| | - Bo Zhang
- Department of Orthopaedics, Affiliated Hospital of Nantong University, Medical School of Nantong University, Nantong, Jiangsu, China
| | - Yafeng Zhang
- Department of Orthopaedics, Affiliated Hospital of Nantong University, Medical School of Nantong University, Nantong, Jiangsu, China
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11
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Hughes JM, Guerriere KI, Popp KL, Castellani CM, Pasiakos SM. Exercise for optimizing bone health after hormone-induced increases in bone stiffness. Front Endocrinol (Lausanne) 2023; 14:1219454. [PMID: 37790607 PMCID: PMC10544579 DOI: 10.3389/fendo.2023.1219454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 08/17/2023] [Indexed: 10/05/2023] Open
Abstract
Hormones and mechanical loading co-regulate bone throughout the lifespan. In this review, we posit that times of increased hormonal influence on bone provide opportunities for exercise to optimize bone strength and prevent fragility. Examples include endogenous secretion of growth hormones and sex steroids that modulate adolescent growth and exogenous administration of osteoanabolic drugs like teriparatide, which increase bone stiffness, or its resistance to external forces. We review evidence that after bone stiffness is increased due to hormonal stimuli, mechanoadaptive processes follow. Specifically, exercise provides the mechanical stimulus necessary to offset adaptive bone resorption or promote adaptive bone formation. The collective effects of both decreased bone resorption and increased bone formation optimize bone strength during youth and preserve it later in life. These theoretical constructs provide physiologic foundations for promoting exercise throughout life.
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Affiliation(s)
- Julie M. Hughes
- Military Performance Division, United States Army Research Institute of Environmental Medicine, Natick, MA, United States
| | - Katelyn I. Guerriere
- Military Performance Division, United States Army Research Institute of Environmental Medicine, Natick, MA, United States
| | - Kristin L. Popp
- Military Performance Division, United States Army Research Institute of Environmental Medicine, Natick, MA, United States
- Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TN, United States
| | - Colleen M. Castellani
- Military Performance Division, United States Army Research Institute of Environmental Medicine, Natick, MA, United States
- Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TN, United States
| | - Stefan M. Pasiakos
- Military Performance Division, United States Army Research Institute of Environmental Medicine, Natick, MA, United States
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12
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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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13
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Dudaric L, Dumic-Cule I, Divjak E, Cengic T, Brkljacic B, Ivanac G. Bone Remodeling in Osteoarthritis-Biological and Radiological Aspects. MEDICINA (KAUNAS, LITHUANIA) 2023; 59:1613. [PMID: 37763732 PMCID: PMC10537088 DOI: 10.3390/medicina59091613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 08/24/2023] [Accepted: 09/05/2023] [Indexed: 09/29/2023]
Abstract
Among available papers published on the given subject over the last century, various terms have been used as synonyms for one, now generally accepted-osteoarthritis, in some countries called "wear and tear" or "overload arthritis". The opsolent terms-hypertrophic arthritis, degenerative arthritis, arthritis deformans and osteoarthrosis-sought to highlight the dominant clinical signs of this ubiquitous, polymorph disease of the whole osteochondral unit, which by incidence and prevalence represents one of the leading chronic conditions that cause long-term pain and incapacity for work. Numerous in vitro and in vivo research resulted in broadened acknowledgments about osteoarthritis pathophysiology and pathology on both histological and cellular levels. However, the cause of osteoarthritis is still unknown and is currently the subject of a hypothesis. In this paper, we provide a review of recent findings on biological phenomena taking place in bone tissue during osteoarthritis to the extent useful for clinical practice. Choosing a proper radiological approach is a conditio sine qua non to the early diagnosis of this entity.
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Affiliation(s)
- Luka Dudaric
- Croatia Poliklinika, Rijeka Radiology Unit, Vukovarska 7A, 51000 Rijeka, Croatia;
| | - Ivo Dumic-Cule
- Clinical Department of Diagnostic and Interventional Radiology, University Hospital Centre Zagreb, Kispaticeva 12, 10000 Zagreb, Croatia;
- Department of Nursing, University North, 104 Brigade 3, 42000 Varazdin, Croatia
| | - Eugen Divjak
- Department of Diagnostic and Interventional Radiology, University Hospital Dubrava, Avenija Gojka Suska 6, 10000 Zagreb, Croatia; (E.D.); (B.B.); (G.I.)
| | - Tomislav Cengic
- Department of Orthopedics and Traumatology, University Hospital Centre Sestre Milosrdnice, Draskoviceva 19, 10000 Zagreb, Croatia
| | - Boris Brkljacic
- Department of Diagnostic and Interventional Radiology, University Hospital Dubrava, Avenija Gojka Suska 6, 10000 Zagreb, Croatia; (E.D.); (B.B.); (G.I.)
- School of Medicine, University of Zagreb, Salata 3, 10000 Zagreb, Croatia
| | - Gordana Ivanac
- Department of Diagnostic and Interventional Radiology, University Hospital Dubrava, Avenija Gojka Suska 6, 10000 Zagreb, Croatia; (E.D.); (B.B.); (G.I.)
- School of Medicine, University of Zagreb, Salata 3, 10000 Zagreb, Croatia
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14
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Arai M, Ochi H, Sunamura S, Ito N, Nangaku M, Takeda S, Sato S. A Novel Long Noncoding RNA in Osteocytes Regulates Bone Formation through the Wnt/β-Catenin Signaling Pathway. Int J Mol Sci 2023; 24:13633. [PMID: 37686441 PMCID: PMC10488071 DOI: 10.3390/ijms241713633] [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: 08/13/2023] [Revised: 08/30/2023] [Accepted: 08/31/2023] [Indexed: 09/10/2023] Open
Abstract
The vast majority of transcribed RNAs are noncoding RNAs. Among noncoding RNAs, long noncoding RNAs (lncRNAs), which contain hundreds to thousands of bases, have received attention in many fields. The vast majority of the constituent cells in bone tissue are osteocytes, but their regulatory mechanisms are incompletely understood. Considering the wide range of potential contributions of lncRNAs to physiological processes and pathological conditions, we hypothesized that lncRNAs in osteocytes, which have not been reported, could be involved in bone metabolism. Here, we first isolated osteocytes from femurs of mice with osteocyte-specific GFP expression. Then, through RNA-sequencing, we identified osteocyte-specific lncRNAs and focused on a novel lncRNA, 9530026P05Rik (lncRNA953Rik), which strongly suppressed osteogenic differentiation. In the IDG-SW3 osteocyte line with lncRNA953Rik overexpression, the expression of Osterix and its downstream genes was reduced. RNA pull-down and subsequent LC-MS/MS analysis revealed that lncRNA953Rik bound the nuclear protein CCAR2. We demonstrated that CCAR2 promoted Wnt/β-catenin signaling and that lncRNA953Rik inhibited this pathway. lncRNA953Rik sequestered CCAR2 from HDAC1, leading to deacetylation of H3K27 in the Osterix promoter and consequent transcriptional downregulation of Osterix. This research is the first to clarify the role of a lncRNA in osteocytes. Our findings can pave the way for novel therapeutic options targeting lncRNAs in osteocytes to treat bone metabolic diseases such as osteoporosis.
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Affiliation(s)
- Makoto Arai
- Division of Nephrology and Endocrinology, The University of Tokyo Hospital, Tokyo 113-8655, Japan
| | - Hiroki Ochi
- Department of Rehabilitation for Motor Functions, Research Institute, National Rehabilitation Center for Persons with Disabilities, Tokorozawa 359-8555, Japan
| | - Satoko Sunamura
- Department of Orthopaedic Surgery, Graduate School, Tokyo Medical and Dental University (TMDU), Tokyo 113-8519, Japan
| | - Nobuaki Ito
- Division of Nephrology and Endocrinology, The University of Tokyo Hospital, Tokyo 113-8655, Japan
- Osteoporosis Center, The University of Tokyo Hospital, Tokyo 113-8655, Japan
| | - Masaomi Nangaku
- Division of Nephrology and Endocrinology, The University of Tokyo Hospital, Tokyo 113-8655, Japan
| | - Shu Takeda
- Division of Endocrinology, Toranomon Hospital Endocrine Center, Tokyo 105-8470, Japan
| | - Shingo Sato
- Center for Innovative Cancer Treatment, Tokyo Medical and Dental University (TMDU), Tokyo 113-8519, Japan
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15
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Krasnova O, Neganova I. Assembling the Puzzle Pieces. Insights for in Vitro Bone Remodeling. Stem Cell Rev Rep 2023; 19:1635-1658. [PMID: 37204634 DOI: 10.1007/s12015-023-10558-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/08/2023] [Indexed: 05/20/2023]
Abstract
As a highly dynamic organ, bone changes during throughout a person's life. This process is referred to as 'bone remodeling' and it involves two stages - a well-balanced osteoclastic bone resorption and an osteoblastic bone formation. Under normal physiological conditions bone remodeling is highly regulated that ensures tight coupling between bone formation and resorption, and its disruption results in a bone metabolic disorder, most commonly osteoporosis. Though osteoporosis is one of the most prevalent skeletal ailments that affect women and men aged over 40 of all races and ethnicities, currently there are few, if any safe and effective therapeutic interventions available. Developing state-of-the-art cellular systems for bone remodeling and osteoporosis can provide important insights into the cellular and molecular mechanisms involved in skeletal homeostasis and advise better therapies for patients. This review describes osteoblastogenesis and osteoclastogenesis as two vital processes for producing mature, active bone cells in the context of interactions between cells and the bone matrix. In addition, it considers current approaches in bone tissue engineering, pointing out cell sources, core factors and matrices used in scientific practice for modeling bone diseases and testing drugs. Finally, it focuses on the challenges that bone regenerative medicine is currently facing.
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Affiliation(s)
- O Krasnova
- Institute of Cytology, Russian Academy of Sciences, Saint-Petersburg, Russia
| | - I Neganova
- Institute of Cytology, Russian Academy of Sciences, Saint-Petersburg, Russia.
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16
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Marahleh A, Kitaura H, Ohori F, Noguchi T, Mizoguchi I. The osteocyte and its osteoclastogenic potential. Front Endocrinol (Lausanne) 2023; 14:1121727. [PMID: 37293482 PMCID: PMC10244721 DOI: 10.3389/fendo.2023.1121727] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 04/07/2023] [Indexed: 06/10/2023] Open
Abstract
The skeleton is an organ of dual functionality; on the one hand, it provides protection and structural competence. On the other hand, it participates extensively in coordinating homeostasis globally given that it is a mineral and hormonal reservoir. Bone is the only tissue in the body that goes through strategically consistent bouts of bone resorption to ensure its integrity and organismal survival in a temporally and spatially coordinated process, known as bone remodeling. Bone remodeling is directly enacted by three skeletal cell types, osteoclasts, osteoblasts, and osteocytes; these cells represent the acting force in a basic multicellular unit and ensure bone health maintenance. The osteocyte is an excellent mechanosensory cell and has been positioned as the choreographer of bone remodeling. It is, therefore, not surprising that a holistic grasp of the osteocyte entity in the bone is warranted. This review discusses osteocytogenesis and associated molecular and morphological changes and describes the osteocytic lacunocanalicular network (LCN) and its organization. We highlight new knowledge obtained from transcriptomic analyses of osteocytes and discuss the regulatory role of osteocytes in promoting osteoclastogenesis with an emphasis on the case of osteoclastogenesis in anosteocytic bones. We arrive at the conclusion that osteocytes exhibit several redundant means through which osteoclast formation can be initiated. However, whether osteocytes are true "orchestrators of bone remodeling" cannot be verified from the animal models used to study osteocyte biology in vivo. Results from studying osteocyte biology using current animal models should come with the caveat that these models are not osteocyte-specific, and conclusions from these studies should be interpreted cautiously.
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Affiliation(s)
- Aseel Marahleh
- Frontier Research Institute for Interdisciplinary Sciences (FRIS), Tohoku University, Sendai, Japan
- Division of Orthodontics and Dentofacial Orthopedics, Graduate School of Dentistry, Tohoku University, Sendai, Japan
| | - Hideki Kitaura
- Division of Orthodontics and Dentofacial Orthopedics, Graduate School of Dentistry, Tohoku University, Sendai, Japan
| | - Fumitoshi Ohori
- Division of Orthodontics and Dentofacial Orthopedics, Graduate School of Dentistry, Tohoku University, Sendai, Japan
| | - Takahiro Noguchi
- Division of Orthodontics and Dentofacial Orthopedics, Graduate School of Dentistry, Tohoku University, Sendai, Japan
| | - Itaru Mizoguchi
- Division of Orthodontics and Dentofacial Orthopedics, Graduate School of Dentistry, Tohoku University, Sendai, Japan
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17
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Xu H, Wang W, Liu X, Huang W, Zhu C, Xu Y, Yang H, Bai J, Geng D. Targeting strategies for bone diseases: signaling pathways and clinical studies. Signal Transduct Target Ther 2023; 8:202. [PMID: 37198232 DOI: 10.1038/s41392-023-01467-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2023] [Revised: 04/02/2023] [Accepted: 04/19/2023] [Indexed: 05/19/2023] Open
Abstract
Since the proposal of Paul Ehrlich's magic bullet concept over 100 years ago, tremendous advances have occurred in targeted therapy. From the initial selective antibody, antitoxin to targeted drug delivery that emerged in the past decades, more precise therapeutic efficacy is realized in specific pathological sites of clinical diseases. As a highly pyknotic mineralized tissue with lessened blood flow, bone is characterized by a complex remodeling and homeostatic regulation mechanism, which makes drug therapy for skeletal diseases more challenging than other tissues. Bone-targeted therapy has been considered a promising therapeutic approach for handling such drawbacks. With the deepening understanding of bone biology, improvements in some established bone-targeted drugs and novel therapeutic targets for drugs and deliveries have emerged on the horizon. In this review, we provide a panoramic summary of recent advances in therapeutic strategies based on bone targeting. We highlight targeting strategies based on bone structure and remodeling biology. For bone-targeted therapeutic agents, in addition to improvements of the classic denosumab, romosozumab, and PTH1R ligands, potential regulation of the remodeling process targeting other key membrane expressions, cellular crosstalk, and gene expression, of all bone cells has been exploited. For bone-targeted drug delivery, different delivery strategies targeting bone matrix, bone marrow, and specific bone cells are summarized with a comparison between different targeting ligands. Ultimately, this review will summarize recent advances in the clinical translation of bone-targeted therapies and provide a perspective on the challenges for the application of bone-targeted therapy in the clinic and future trends in this area.
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Affiliation(s)
- Hao Xu
- Department of Orthopedics, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, Jiangsu, 215006, P. R. China
| | - Wentao Wang
- Department of Orthopedics, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, Jiangsu, 215006, P. R. China
| | - Xin Liu
- Department of Orthopedics, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, Jiangsu, 215006, P. R. China
| | - Wei Huang
- Department of Orthopedics, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230031, Anhui, China
| | - Chen Zhu
- Department of Orthopedics, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230031, Anhui, China
| | - Yaozeng Xu
- Department of Orthopedics, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, Jiangsu, 215006, P. R. China
| | - Huilin Yang
- Department of Orthopedics, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, Jiangsu, 215006, P. R. China.
- Orthopaedic Institute, Medical College, Soochow University, Suzhou, 215006, Jiangsu, China.
| | - Jiaxiang Bai
- Department of Orthopedics, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, Jiangsu, 215006, P. R. China.
- Orthopaedic Institute, Medical College, Soochow University, Suzhou, 215006, Jiangsu, China.
| | - Dechun Geng
- Department of Orthopedics, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, Jiangsu, 215006, P. R. China.
- Orthopaedic Institute, Medical College, Soochow University, Suzhou, 215006, Jiangsu, China.
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18
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Peurière L, Mastrandrea C, Vanden-Bossche A, Linossier MT, Thomas M, Normand M, Lafage-Proust MH, Vico L. Hindlimb unloading in C57BL/6J mice induces bone loss at thermoneutrality without change in osteocyte and lacuno-canalicular network. Bone 2023; 169:116640. [PMID: 36526262 DOI: 10.1016/j.bone.2022.116640] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 11/13/2022] [Accepted: 11/30/2022] [Indexed: 12/15/2022]
Abstract
Impaired mechanical stimuli during hindlimb unloading (HLU) are believed to exacerbate osteocyte paracrine regulation of osteoclasts. We hypothesized that bone loss and deterioration of the osteocyte lacuno-canalicular network are attenuated in HLU mice housed at thermoneutrality (28 °C) compared with those housed at ambient temperature (22 °C). Following acclimatization, 20-week-old male C57BL/6J mice were submitted to HLU or kept in pair-fed control cages (CONT), for 5 days (5d) or 14d, at 22 °C or 28 °C. In the femur distal metaphysis, thermoneutral CONT mice had higher bone volume (p = 0.0007, BV/TV, in vivo μCT, vs. 14dCONT22) whilst osteoclastic surfaces of CONT and HLU were greater at 22 °C (5dCONT22 + 53 %, 5dHLU22 + 50 %, 14dCONT22 + 186 %, 14dHLU22 + 104 %, vs matching 28 °C group). In the femur diaphysis and at both temperatures, 14dHLU exhibited thinner cortices distally or proximally compared to controls; the mid-diaphysis being thicker at 28 °C than at 22 °C in all groups. Expression of cortical genes for proteolytic enzyme (Mmp13), markers for osteoclastogenic differentiation (MCSF, RANKL), and activity (TRAP, Ctsk) were increased following 22 °C HLU, whereas only Ctsk expression was increased following 28 °C HLU. Expression of cortical genes for apoptosis, senescence, and autophagy were not elevated following HLU at any temperature. Osteocyte density at the posterior mid-diaphysis was similar between groups, as was the proportion of empty lacunae (<0.5 %). However, analysis of the lacuno-canalicular network (LCN, fluorescein staining) revealed unstained areas in the 14dHLU22 group only, suggesting disrupted LCN flow in this group alone. In conclusion, 28 °C housing influences the HLU bone response but does not prevent bone loss. Furthermore, our results do not show osteocyte senescence or death, and at thermoneutrality, HLU-induced bone resorption is not triggered by osteoclastic activators RANKL and MCSF.
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Affiliation(s)
- Laura Peurière
- Université Jean Monnet Saint-Étienne, Mines Saint-Étienne, INSERM, SAINBIOSE U1059, F-42023, Saint-Étienne, France.
| | - Carmelo Mastrandrea
- Université Jean Monnet Saint-Étienne, Mines Saint-Étienne, INSERM, SAINBIOSE U1059, F-42023, Saint-Étienne, France
| | - Arnaud Vanden-Bossche
- Université Jean Monnet Saint-Étienne, Mines Saint-Étienne, INSERM, SAINBIOSE U1059, F-42023, Saint-Étienne, France
| | - Marie-Thérèse Linossier
- Université Jean Monnet Saint-Étienne, Mines Saint-Étienne, INSERM, SAINBIOSE U1059, F-42023, Saint-Étienne, France
| | - Mireille Thomas
- Université Jean Monnet Saint-Étienne, Mines Saint-Étienne, INSERM, SAINBIOSE U1059, F-42023, Saint-Étienne, France
| | - Myriam Normand
- Université Jean Monnet Saint-Étienne, Mines Saint-Étienne, INSERM, SAINBIOSE U1059, F-42023, Saint-Étienne, France
| | - Marie-Hélène Lafage-Proust
- Université Jean Monnet Saint-Étienne, Mines Saint-Étienne, INSERM, SAINBIOSE U1059, F-42023, Saint-Étienne, France
| | - Laurence Vico
- Université Jean Monnet Saint-Étienne, Mines Saint-Étienne, INSERM, SAINBIOSE U1059, F-42023, Saint-Étienne, France
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19
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Shimizu N, Fujiwara K, Mayahara K, Motoyoshi M, Takahashi T. Tension force causes cell cycle arrest at G2/M phase in osteocyte-like cell line MLO-Y4. Heliyon 2023; 9:e13236. [PMID: 36798766 PMCID: PMC9925960 DOI: 10.1016/j.heliyon.2023.e13236] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 01/12/2023] [Accepted: 01/23/2023] [Indexed: 01/26/2023] Open
Abstract
Bone remodelling is the process of bone resorption and formation, necessary to maintain bone structure or for adaptation to new conditions. Mechanical loadings, such as exercise, weight bearing and orthodontic force, play important roles in bone remodelling. During the remodelling process, osteocytes play crucial roles as mechanosensors to regulate osteoblasts and osteoclasts. However, the precise molecular mechanisms by which the mechanical stimuli affect the function of osteocytes remain unclear. In the present study, we analysed viability, cell cycle distribution and gene expression pattern of murine osteocyte-like MLO-Y4 cells exposed to tension force (TF). Cells were subjected to TF with 18% elongation at 6 cycles/min for 24 h using Flexcer Strain Unit (FX-3000). We found that TF stimulation induced cell cycle arrest at G2/M phase but not cell death in MLO-Y4 cells. Differentially expressed genes (DEGs) between TF-stimulated and unstimulated cells were identified by microarray analysis, and a marked increase in glutathione-S-transferase α (GSTA) family gene expression was observed in TF-stimulated cells. Enrichment analysis for the DEGs revealed that Gene Ontology (GO) terms and Kyoto Encyclopedia Genes and Genomes (KEGG) pathways related to the stress response were significantly enriched among the upregulated genes following TF. Consistent with these results, the production of reactive oxygen species (ROS) was elevated in TF-stimulated cells. Activation of the tumour suppressor p53, and upregulation of its downstream target GADD45A, were also observed in the stimulated cells. As GADD45A has been implicated in the promotion of G2/M cell cycle arrest, these observations may suggest that TF stress leads to G2/M arrest at least in part in a p53-dependent manner.
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Affiliation(s)
- Natsuo Shimizu
- Department of Orthodontics, Nihon University School of Dentistry, 1-8-3 Kanda-Surugadai, Chiyoda-ku, Tokyo, 101-8310, Japan
- Division of Applied Oral Science, Nihon University Graduate School of Dentistry, 1-8-3 Kanda-Surugadai, Chiyoda-ku, Tokyo, 101-8310, Japan
| | - Kyoko Fujiwara
- Department of Anatomy, Nihon University School of Dentistry, 1-8-3 Kanda-Surugadai, Chiyoda-ku, Tokyo, 101-8310, Japan
- Division of Functional Morphology, Dental Research Center, Nihon University School of Dentistry, 1-8-3 Kanda-Surugadai, Chiyoda-ku, Tokyo, 101-8310, Japan
- Corresponding author. Department of Anatomy, Nihon University School of Dentistry, 1-8-3 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan.
| | - Kotoe Mayahara
- Department of Orthodontics, Nihon University School of Dentistry, 1-8-3 Kanda-Surugadai, Chiyoda-ku, Tokyo, 101-8310, Japan
- Division of Clinical Research, Dental Research Centre, Nihon University School of Dentistry, 1-8-3 Kanda-Surugadai, Chiyoda-ku, Tokyo, 101-8310, Japan
| | - Mitsuru Motoyoshi
- Department of Orthodontics, Nihon University School of Dentistry, 1-8-3 Kanda-Surugadai, Chiyoda-ku, Tokyo, 101-8310, Japan
- Division of Clinical Research, Dental Research Centre, Nihon University School of Dentistry, 1-8-3 Kanda-Surugadai, Chiyoda-ku, Tokyo, 101-8310, Japan
| | - Tomihisa Takahashi
- Department of Anatomy, Nihon University School of Dentistry, 1-8-3 Kanda-Surugadai, Chiyoda-ku, Tokyo, 101-8310, Japan
- Division of Functional Morphology, Dental Research Center, Nihon University School of Dentistry, 1-8-3 Kanda-Surugadai, Chiyoda-ku, Tokyo, 101-8310, Japan
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20
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Resveratrol protects osteocytes against oxidative stress in ovariectomized rats through AMPK/JNK1-dependent pathway leading to promotion of autophagy and inhibition of apoptosis. Cell Death Dis 2023; 9:16. [PMID: 36681672 PMCID: PMC9867734 DOI: 10.1038/s41420-023-01331-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 01/09/2023] [Accepted: 01/11/2023] [Indexed: 01/22/2023]
Abstract
A large number of studies in recent years indicate that osteocytes are the orchestrators of bone remodeling by regulating both osteoblast and osteoclast activities. Oxidative stress-induced osteocyte apoptosis plays critical roles in the pathological processes of postmenopausal osteoporosis. Resveratrol is a natural polyphenolic compound that ameliorates postmenopausal osteoporosis. However, whether resveratrol regulates osteocyte apoptosis via autophagy remains largely unknown. The effects of resveratrol on regulating osteocyte apoptosis and autophagy were analyzed both in vivo and in vitro. In vitro, cultured MLO-Y4 cells were exposed to H2O2 with or without resveratrol. In vivo, an ovariectomy-induced osteoporosis model was constructed in rats with or without daily intraperitoneal injection of 10 mg/kg body weight resveratrol. It was found that resveratrol attenuated H2O2-induced apoptosis through activating autophagy in cultured MLO-Y4 cells, which was mediated by the dissociation of Beclin-1/Bcl-2 complex in AMPK/JNK1-dependent pathway, ultimately regulating osteocytes function. Furthermore, it was shown that resveratrol treatment reduced osteocytes oxidative stress, inhibited osteocytes apoptosis and promoted autophagy in ovariectomized rats. Our study suggests that resveratrol protects against oxidative stress by restoring osteocytes autophagy and alleviating apoptosis via AMPK/JNK1 activation, therefore dissociating Bcl-2 from Beclin-1.
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21
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Bolamperti S, Villa I, Rubinacci A. Bone remodeling: an operational process ensuring survival and bone mechanical competence. Bone Res 2022; 10:48. [PMID: 35851054 PMCID: PMC9293977 DOI: 10.1038/s41413-022-00219-8] [Citation(s) in RCA: 91] [Impact Index Per Article: 45.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 05/02/2022] [Accepted: 05/15/2022] [Indexed: 12/12/2022] Open
Abstract
Bone remodeling replaces old and damaged bone with new bone through a sequence of cellular events occurring on the same surface without any change in bone shape. It was initially thought that the basic multicellular unit (BMU) responsible for bone remodeling consists of osteoclasts and osteoblasts functioning through a hierarchical sequence of events organized into distinct stages. However, recent discoveries have indicated that all bone cells participate in BMU formation by interacting both simultaneously and at different differentiation stages with their progenitors, other cells, and bone matrix constituents. Therefore, bone remodeling is currently considered a physiological outcome of continuous cellular operational processes optimized to confer a survival advantage. Bone remodeling defines the primary activities that BMUs need to perform to renew successfully bone structural units. Hence, this review summarizes the current understanding of bone remodeling and future research directions with the aim of providing a clinically relevant biological background with which to identify targets for therapeutic strategies in osteoporosis.
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Affiliation(s)
- Simona Bolamperti
- Osteoporosis and Bone and Mineral Metabolism Unit, IRCCS San Raffaele Hospital, Via Olgettina 60, 20132, Milano, Italy
| | - Isabella Villa
- Osteoporosis and Bone and Mineral Metabolism Unit, IRCCS San Raffaele Hospital, Via Olgettina 60, 20132, Milano, Italy
| | - Alessandro Rubinacci
- Osteoporosis and Bone and Mineral Metabolism Unit, IRCCS San Raffaele Hospital, Via Olgettina 60, 20132, Milano, Italy.
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22
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Cui J, Shibata Y, Zhu T, Zhou J, Zhang J. Osteocytes in bone aging: Advances, challenges, and future perspectives. Ageing Res Rev 2022; 77:101608. [PMID: 35283289 DOI: 10.1016/j.arr.2022.101608] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 02/28/2022] [Accepted: 03/07/2022] [Indexed: 02/08/2023]
Abstract
Osteocytes play a critical role in maintaining bone homeostasis and in regulating skeletal response to hormones and mechanical loading. Substantial evidence have demonstrated that osteocytes and their lacunae exhibit morphological changes in aged bone, indicating the underlying involvement of osteocytes in bone aging. Notably, recent studies have deciphered aged osteocytes to have characteristics such as impaired mechanosensitivity, accumulated cellular senescence, dysfunctional perilacunar/canalicular remodeling, and degenerated lacuna-canalicular network. However, detailed molecular mechanisms of osteocytes remain unclear. Nonetheless, osteocyte transcriptomes analyzed via advanced RNA sequencing (RNA-seq) techniques have identified several bone aging-related genes and signaling pathways, such as Wnt, Bmp/TGF, and Jak-STAT. Moreover, inflammation, immune dysfunction, energy shortage, and impaired hormone responses possibly affect osteocytes in age-related bone deterioration. In this review, we summarize the hallmarks of aging bone and osteocytes and discuss osteocytic mechanisms in age-related bone loss and impaired bone quality. Furthermore, we provide insights into the challenges faced and their possible solutions when investigating osteocyte transcriptomes. We also highlight that single-cell RNA-seq can decode transcriptomic messages in aged osteocytes; therefore, this technique can promote novel single cell-based investigations in osteocytes once a well-established standardized protocol specific for osteocytes is developed. Interestingly, improved understanding of osteocytic mechanisms have helped identify promising targets and effective therapies for aging-related osteoporosis and fragile fractures.
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23
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Hoenig T, Ackerman KE, Beck BR, Bouxsein ML, Burr DB, Hollander K, Popp KL, Rolvien T, Tenforde AS, Warden SJ. Bone stress injuries. Nat Rev Dis Primers 2022; 8:26. [PMID: 35484131 DOI: 10.1038/s41572-022-00352-y] [Citation(s) in RCA: 43] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/11/2022] [Indexed: 01/11/2023]
Abstract
Bone stress injuries, including stress fractures, are overuse injuries that lead to substantial morbidity in active individuals. These injuries occur when excessive repetitive loads are introduced to a generally normal skeleton. Although the precise mechanisms for bone stress injuries are not completely understood, the prevailing theory is that an imbalance in bone metabolism favours microdamage accumulation over its removal and replacement with new bone via targeted remodelling. Diagnosis is achieved by a combination of patient history and physical examination, with imaging used for confirmation. Management of bone stress injuries is guided by their location and consequent risk of healing complications. Bone stress injuries at low-risk sites typically heal with activity modification followed by progressive loading and return to activity. Additional treatment approaches include non-weight-bearing immobilization, medications or surgery, but these approaches are usually limited to managing bone stress injuries that occur at high-risk sites. A comprehensive strategy that integrates anatomical, biomechanical and biological risk factors has the potential to improve the understanding of these injuries and aid in their prevention and management.
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Affiliation(s)
- Tim Hoenig
- Department of Trauma and Orthopaedic Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
| | - Kathryn E Ackerman
- Wu Tsai Female Athlete Program, Boston Children's Hospital, Boston, MA, USA.,Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Belinda R Beck
- School of Health Sciences & Social Work, Griffith University, Gold Coast, Queensland, Australia.,Menzies Health Institute Queensland, Gold Coast, Queensland, Australia.,The Bone Clinic, Brisbane, Queensland, Australia
| | - Mary L Bouxsein
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.,Department of Orthopedic Surgery, Harvard Medical School and Center for Advanced Orthopedic Studies, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - David B Burr
- Department of Anatomy, Cell Biology, and Physiology, Indiana University School of Medicine, Indiana University, Indianapolis, IN, USA.,Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indiana University, Indianapolis, IN, USA
| | - Karsten Hollander
- Institute of Interdisciplinary Exercise Science and Sports Medicine, MSH Medical School Hamburg, Hamburg, Germany
| | - Kristin L Popp
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.,U.S. Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Tim Rolvien
- Department of Trauma and Orthopaedic Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Adam S Tenforde
- Spaulding Rehabilitation Hospital, Department of Physical Medicine and Rehabilitation, Harvard Medical School, Charlestown, MA, USA.
| | - Stuart J Warden
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indiana University, Indianapolis, IN, USA. .,Department of Physical Therapy, School of Health & Human Sciences, Indiana University, Indianapolis, IN, USA. .,La Trobe Sport and Exercise Medicine Research Centre, La Trobe University, Bundoora, Victoria, Australia.
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24
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Geurtzen K, López-Delgado AC, Duseja A, Kurzyukova A, Knopf F. Laser-mediated osteoblast ablation triggers a pro-osteogenic inflammatory response regulated by reactive oxygen species and glucocorticoid signaling in zebrafish. Development 2022; 149:275194. [DOI: 10.1242/dev.199803] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 02/22/2022] [Indexed: 12/31/2022]
Abstract
ABSTRACT
In zebrafish, transgenic labeling approaches, robust regenerative responses and excellent in vivo imaging conditions enable precise characterization of immune cell behavior in response to injury. Here, we monitored osteoblast-immune cell interactions in bone, a tissue which is particularly difficult to in vivo image in tetrapod species. Ablation of individual osteoblasts leads to recruitment of neutrophils and macrophages in varying numbers, depending on the extent of the initial insult, and initiates generation of cathepsin K+ osteoclasts from macrophages. Osteoblast ablation triggers the production of pro-inflammatory cytokines and reactive oxygen species, which are needed for successful macrophage recruitment. Excess glucocorticoid signaling as it occurs during the stress response inhibits macrophage recruitment, maximum speed and changes the macrophage phenotype. Although osteoblast loss is compensated for within a day by contribution of committed osteoblasts, macrophages continue to populate the region. Their presence is required for osteoblasts to fill the lesion site. Our model enables visualization of bone repair after microlesions at single-cell resolution and demonstrates a pro-osteogenic function of tissue-resident macrophages in non-mammalian vertebrates.
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Affiliation(s)
- Karina Geurtzen
- Center for Regenerative Therapies TU Dresden (CRTD), Center for Molecular and Cellular Bioengineering (CMCB), TU Dresden, 01307 Dresden, Germany
- Center for Healthy Aging, Medical Faculty Carl Gustav Carus, TU Dresden, 01307 Dresden, Germany
- Laboratory of Clinical and Experimental Endocrinology, Department of Chronic Diseases, Metabolism and Ageing, KU Leuven, 3000 Leuven, Belgium
| | - Alejandra Cristina López-Delgado
- Center for Regenerative Therapies TU Dresden (CRTD), Center for Molecular and Cellular Bioengineering (CMCB), TU Dresden, 01307 Dresden, Germany
- Center for Healthy Aging, Medical Faculty Carl Gustav Carus, TU Dresden, 01307 Dresden, Germany
| | - Ankita Duseja
- Center for Regenerative Therapies TU Dresden (CRTD), Center for Molecular and Cellular Bioengineering (CMCB), TU Dresden, 01307 Dresden, Germany
- Center for Healthy Aging, Medical Faculty Carl Gustav Carus, TU Dresden, 01307 Dresden, Germany
- Department of Oncology and Metabolism, Metabolic Bone Centre, Sorby Wing, Northern General Hospital, Sheffield S5 7AU, UK
| | - Anastasia Kurzyukova
- Center for Regenerative Therapies TU Dresden (CRTD), Center for Molecular and Cellular Bioengineering (CMCB), TU Dresden, 01307 Dresden, Germany
- Center for Healthy Aging, Medical Faculty Carl Gustav Carus, TU Dresden, 01307 Dresden, Germany
- Faculty of Health and Medical Sciences, Biotech Research & Innovation Centre (BRIC), University of Copenhagen, 2200 Copenhagen, Denmark
| | - Franziska Knopf
- Center for Regenerative Therapies TU Dresden (CRTD), Center for Molecular and Cellular Bioengineering (CMCB), TU Dresden, 01307 Dresden, Germany
- Center for Healthy Aging, Medical Faculty Carl Gustav Carus, TU Dresden, 01307 Dresden, Germany
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25
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Grewe JM, Knapstein PR, Donat A, Jiang S, Smit DJ, Xie W, Keller J. The role of sphingosine-1-phosphate in bone remodeling and osteoporosis. Bone Res 2022; 10:34. [PMID: 35396384 PMCID: PMC8993882 DOI: 10.1038/s41413-022-00205-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 11/17/2021] [Accepted: 01/17/2022] [Indexed: 12/27/2022] Open
Abstract
Osteoporosis is a systemic bone disease that affects more than 200 million people worldwide and is caused by the disruption of the equilibrium between osteoclastic bone resorption and osteoblastic bone formation. Sphingosine-1-phosphate (S1P) is a natural, bioactive sphingolipid that has been shown to play a major role in cardiovascular and immunological pathologies by regulating biological and cellular processes, including migration, differentiation, proliferation and survival. Recent studies also suggest a central role for S1P in bone diseases, including osteoporosis; however, the effects of S1P, particularly in bone metabolism, remain to be further elucidated. In this review, we summarize the available literature on the role of S1P in bone metabolism with a focus on osteoporosis. On the cellular level, S1P acts as an osteoclast-osteoblast coupling factor to promote osteoblast proliferation and bone formation. Moreover, the recruitment of osteoclast precursors to resorption sites is regulated by the interplay of S1P gradients and S1P receptor expression. From a clinical perspective, increasing evidence suggests that systemically elevated S1P blood levels may serve as an independent risk factor for osteoporosis-related fractures. Taken together, S1P signaling is a potential therapeutic target and may serve as a novel biomarker in patients with systemic bone disease.
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Affiliation(s)
- Justus M Grewe
- Department of Trauma and Orthopedic Surgery, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany.,Clinic and Polyclinic for Vascular Medicine, University Heart Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Paul-Richard Knapstein
- Department of Trauma and Orthopedic Surgery, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Antonia Donat
- Department of Trauma and Orthopedic Surgery, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Shan Jiang
- Department of Trauma and Orthopedic Surgery, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Daniel J Smit
- Institute of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Weixin Xie
- Department of Trauma and Orthopedic Surgery, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Johannes Keller
- Department of Trauma and Orthopedic Surgery, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany.
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26
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Kaspiris A, Chronopoulos E, Vasiliadis E, Khaldi L, Melissaridou D, Iliopoulos ID, Savvidou OD. Sex, but not age and bone mass index positively impact on the development of osteochondral micro‐defects and the accompanying cellular alterations during osteoarthritis progression. Chronic Dis Transl Med 2022; 8:41-50. [PMID: 35620158 PMCID: PMC9128565 DOI: 10.1002/cdt3.16] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 12/09/2021] [Indexed: 11/25/2022] Open
Abstract
Background Osteoarthritis (ΟΑ) is characterized by cartilage breakdown and subchondral sclerosis. Micro‐fractures of the calcified tissues have been, also, detected, but their exact role has not been elucidated yet. This study was to examine the frequency of cracks during OA progression and to correlate them with the underlying cellular modifications and matrix metalloproteinase‐2 (MMP‐2) expression using histological/immunohistological methods. Methods Overall, 20 patients and 3 controls (9 specimens per patient), aged 60–89 years, diagnosed with hip/knee OA were included. The development of cracks was examined in 138 sections, whereas the expression of MMP‐2 was examined in 69 additional sections. Results Based on Mankin score, three groups of OA severity were analyzed: Group I (mild) was constituted of sections with score 1–5 while Groups II (moderate) and III (severe) with score 6–7 and greater or equal to 8, respectively. Demographic characteristics did not reveal any association between the number of microdefects and age or body mass index (BMI). Cartilage micro‐cracks were increased during moderate and severe OA, while bone cracks were increased during mild and severe OA. In knee OA, cartilage cracks were not correlated with Mankin score, whereas in hip OA they appeared association with severity score. Bone cracks were positively correlated with matrix apoptotic osteocytes and osteoblastic cells, but not with osteoclasts. MMP‐2 immunostaining was increasing by OA severity in the osteochondral unit. Similarly, MMP‐2 was expressed on the microcracks’ wall mainly in Group III. Conclusion Our data displayed that bone cracks during primary OA stages, represent an early adaptative mechanism aiming to maintain cartilage integrity. Accumulation of bone defects and concomitant increase of apoptotic osteocytes activated an abnormal remodeling due to osteoblastic activity, in which MMP‐2 played a pivotal role, leading to subchondral sclerosis promoting further osteochondral deformities.
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Affiliation(s)
- Angelos Kaspiris
- Laboratory of Molecular Pharmacology, Division for Orthopaedic Research, School of Health Sciences University of Patras Patras Greece
| | - Efstathios Chronopoulos
- Second Department of Orthopaedic Surgery, School of Medicine National and Kapodistrian University of Athens, “Konstantopoulio” General Hospital Athens Greece
| | - Elias Vasiliadis
- Third Department of Orthopaedic Surgery “KAT” General Hospital and Medical School University of Athens Athens Greece
| | - Lubna Khaldi
- Department of Pathology “Agios Savvas” Athens Cancer Hospital–NHS Athens Greece
| | - Dimitra Melissaridou
- First Department of Orthopaedic Surgery, School of Medicine National and Kapodistrian University of Athens, “ATTIKON” University General Hospital Athens Greece
| | - Ilias D. Iliopoulos
- Department of Orthopaedic Surgery, “Rion” University Hospital and Medical School, School of Health Sciences University of Patras Patras Greece
| | - Olga D. Savvidou
- First Department of Orthopaedic Surgery, School of Medicine National and Kapodistrian University of Athens, “ATTIKON” University General Hospital Athens Greece
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27
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Hodgkinson T, Amado IN, O'Brien FJ, Kennedy OD. The role of mechanobiology in bone and cartilage model systems in characterizing initiation and progression of osteoarthritis. APL Bioeng 2022. [DOI: 10.1063/5.0068277] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Affiliation(s)
- Tom Hodgkinson
- Department of Anatomy and Regenerative Medicine, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Isabel N. Amado
- Department of Anatomy and Regenerative Medicine, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Fergal J. O'Brien
- Department of Anatomy and Regenerative Medicine, Royal College of Surgeons in Ireland, Dublin, Ireland
- Advanced Materials Bio-Engineering Research Centre (AMBER), Dublin, Ireland
- Trinity Centre for Biomedical Engineering, Trinity College Dublin, Dublin, Ireland
| | - Oran D. Kennedy
- Department of Anatomy and Regenerative Medicine, Royal College of Surgeons in Ireland, Dublin, Ireland
- Advanced Materials Bio-Engineering Research Centre (AMBER), Dublin, Ireland
- Trinity Centre for Biomedical Engineering, Trinity College Dublin, Dublin, Ireland
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28
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Kitaura H, Marahleh A, Ohori F, Noguchi T, Nara Y, Pramusita A, Kinjo R, Ma J, Kanou K, Mizoguchi I. Role of the Interaction of Tumor Necrosis Factor-α and Tumor Necrosis Factor Receptors 1 and 2 in Bone-Related Cells. Int J Mol Sci 2022; 23:ijms23031481. [PMID: 35163403 PMCID: PMC8835906 DOI: 10.3390/ijms23031481] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 01/24/2022] [Accepted: 01/26/2022] [Indexed: 02/04/2023] Open
Abstract
Tumor necrosis factor-α (TNF-α) is a pleiotropic cytokine expressed by macrophages, monocytes, and T cells, and its expression is triggered by the immune system in response to pathogens and their products, such as endotoxins. TNF-α plays an important role in host defense by inducing inflammatory reactions such as phagocytes and cytocidal systems activation. TNF-α also plays an important role in bone metabolism and is associated with inflammatory bone diseases. TNF-α binds to two cell surface receptors, the 55kDa TNF receptor-1 (TNFR1) and the 75kDa TNF receptor-2 (TNFR2). Bone is in a constant state of turnover; it is continuously degraded and built via the process of bone remodeling, which results from the regulated balance between bone-resorbing osteoclasts, bone-forming osteoblasts, and the mechanosensory cell type osteocytes. Precise interactions between these cells maintain skeletal homeostasis. Studies have shown that TNF-α affects bone-related cells via TNFRs. Signaling through either receptor results in different outcomes in different cell types as well as in the same cell type. This review summarizes and discusses current research on the TNF-α and TNFR interaction and its role in bone-related cells.
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29
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Abstract
Osteocytes, former osteoblasts encapsulated by mineralized bone matrix, are far from being passive and metabolically inactive bone cells. Instead, osteocytes are multifunctional and dynamic cells capable of integrating hormonal and mechanical signals and transmitting them to effector cells in bone and in distant tissues. Osteocytes are a major source of molecules that regulate bone homeostasis by integrating both mechanical cues and hormonal signals that coordinate the differentiation and function of osteoclasts and osteoblasts. Osteocyte function is altered in both rare and common bone diseases, suggesting that osteocyte dysfunction is directly involved in the pathophysiology of several disorders affecting the skeleton. Advances in osteocyte biology initiated the development of novel therapeutics interfering with osteocyte-secreted molecules. Moreover, osteocytes are targets and key distributors of biological signals mediating the beneficial effects of several bone therapeutics used in the clinic. Here we review the most recent discoveries in osteocyte biology demonstrating that osteocytes regulate bone homeostasis and bone marrow fat via paracrine signaling, influence body composition and energy metabolism via endocrine signaling, and contribute to the damaging effects of diabetes mellitus and hematologic and metastatic cancers in the skeleton.
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Affiliation(s)
- Jesus Delgado-Calle
- 1Department of Physiology and Cell Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas,2Winthrop P. Rockefeller Cancer Institute, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Teresita Bellido
- 1Department of Physiology and Cell Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas,2Winthrop P. Rockefeller Cancer Institute, University of Arkansas for Medical Sciences, Little Rock, Arkansas,3Central Arkansas Veterans Healthcare System, Little Rock, Arkansas
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30
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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.
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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
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31
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Du J, He Z, Cui J, Li H, Xu M, Zhang S, Zhang S, Yan M, Qu X, Yu Z. Osteocyte Apoptosis Contributes to Cold Exposure-induced Bone Loss. Front Bioeng Biotechnol 2021; 9:733582. [PMID: 34858954 PMCID: PMC8632005 DOI: 10.3389/fbioe.2021.733582] [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] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 09/27/2021] [Indexed: 12/19/2022] Open
Abstract
Emerging evidence indicates that bone mass is regulated by systemic energy balance. Temperature variations have profound effects on energy metabolism in animals, which will affect bone remodeling. But the mechanism remains unclear. 2-month-old C57BL/6J male mice were exposed to cold (4°C) and normal (23°C) temperatures for 28 days and the effects of cold exposure on bone mass was investigated. Micro-computed tomography results showed that bone volume fraction was significantly reduced after 14 days of exposure to cold temperature, and it was recovered after 28 days. Ploton silver staining and immunohistochemical results further revealed that exposure to cold decreased canalicular length, number of E11-and MMP13-positive osteocytes after 14 days, but they returned to the baseline levels after 28 days, different from the normal temperature control group. In addition, change of Caspase-3 indicated that exposure to cold temperature augmented apoptosis of osteocytes. In vitro results confirmed the positive effect of brown adipocytes on osteocyte‘s dendrites and E11 expression. In conclusion, our findings indicate that cold exposure can influence bone mass in a time-dependent manner, with bone mass decreasing and recovering at 2 and 4 weeks respectively. The change of bone mass may be caused by the apoptosis osteocytes. Brown adipocyte tissue could influence bone remodeling through affecting osteocyte.
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Affiliation(s)
- Jingke Du
- Shanghai Key Laboratory of Orthopedic Implants, Department of Orthopedic Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zihao He
- Arthritis Clinic and Research Center, Peking University People's Hospital, Peking University, Beijing, China
| | - Junqi Cui
- Department of Pathology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Hanjun Li
- Shanghai Key Laboratory of Orthopedic Implants, Department of Orthopedic Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Mingming Xu
- Shanghai Key Laboratory of Orthopedic Implants, Department of Orthopedic Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Shuhong Zhang
- Shanghai Key Laboratory of Orthopedic Implants, Department of Orthopedic Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Shuangyan Zhang
- Shanghai Key Laboratory of Orthopedic Implants, Department of Orthopedic Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Mengning Yan
- Shanghai Key Laboratory of Orthopedic Implants, Department of Orthopedic Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xinhua Qu
- Department of Bone and Joint Surgery, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Zhifeng Yu
- Shanghai Key Laboratory of Orthopedic Implants, Department of Orthopedic Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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32
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Abstract
PURPOSE OF REVIEW Osteocytes are considered to be the cells responsible for mastering the remodeling process that follows the exposure to unloading conditions. Given the invasiveness of bone biopsies in humans, both rodents and in vitro culture systems are largely adopted as models for studies in space missions or in simulated microgravity conditions models on Earth. RECENT FINDINGS After a brief recall of the main changes in bone mass and osteoclastic and osteoblastic activities in space-related models, this review focuses on the potential role of osteocytes in directing these changes. The role of the best-known signalling molecules is questioned, in particular in relation to osteocyte apoptosis. The mechanotransduction actors identified in spatial conditions and the problems related to fluid flow and shear stress changes, probably enhanced by the alteration in fluid flow and lack of convection during spaceflight, are recalled and discussed.
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Affiliation(s)
- Donata Iandolo
- U1059 INSERM - SAINBIOSE (SAnté INgéniérie BIOlogie St-Etienne) Campus Santé Innovation, Université Jean Monnet, Saint-Priest-en-Jarez, France
| | - Maura Strigini
- U1059 INSERM - SAINBIOSE (SAnté INgéniérie BIOlogie St-Etienne) Campus Santé Innovation, Université Jean Monnet, Saint-Priest-en-Jarez, France
| | - Alain Guignandon
- U1059 INSERM - SAINBIOSE (SAnté INgéniérie BIOlogie St-Etienne) Campus Santé Innovation, Université Jean Monnet, Saint-Priest-en-Jarez, France
| | - Laurence Vico
- U1059 INSERM - SAINBIOSE (SAnté INgéniérie BIOlogie St-Etienne) Campus Santé Innovation, Université Jean Monnet, Saint-Priest-en-Jarez, France.
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Dixit M, Duran‐Ortiz S, Yildirim G, Poudel SB, Louis LD, Bartke A, Schaffler MB, Kopchick JJ, Yakar S. Induction of somatopause in adult mice compromises bone morphology and exacerbates bone loss during aging. Aging Cell 2021; 20:e13505. [PMID: 34811875 PMCID: PMC8672783 DOI: 10.1111/acel.13505] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 08/31/2021] [Accepted: 09/29/2021] [Indexed: 12/23/2022] Open
Abstract
Somatopause refers to the gradual declines in growth hormone (GH) and insulin‐like growth factor‐1 throughout aging. To define how induced somatopause affects skeletal integrity, we used an inducible GH receptor knockout (iGHRKO) mouse model. Somatopause, induced globally at 6 months of age, resulted in significantly more slender bones in both male and female iGHRKO mice. In males, induced somatopause was associated with progressive expansion of the marrow cavity leading to significant thinning of the cortices, which compromised bone strength. We report progressive declines in osteocyte lacunar number, and increases in lacunar volume, in iGHRKO males, and reductions in lacunar number accompanied by ~20% loss of overall canalicular connectivity in iGHRKO females by 30 months of age. Induced somatopause did not affect mineral/matrix ratio assessed by Raman microspectroscopy. We found significant increases in bone marrow adiposity and high levels of sclerostin, a negative regulator of bone formation in iGHRKO mice. Surprisingly, however, despite compromised bone morphology, osteocyte senescence was reduced in the iGHRKO mice. In this study, we avoided the confounded effects of constitutive deficiency in the GH/IGF‐1 axis on the skeleton during growth, and specifically dissected its effects on the aging skeleton. We show here, for the first time, that induced somatopause compromises bone morphology and the bone marrow environment.
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Affiliation(s)
- Manisha Dixit
- David B. Kriser Dental Center Department of Molecular Pathobiology New York University College of Dentistry New York New York NY USA
| | - Silvana Duran‐Ortiz
- Edison Biotechnology Institute and Dept. of Biomedical Sciences Ohio University Athens OH USA
| | - Godze Yildirim
- David B. Kriser Dental Center Department of Molecular Pathobiology New York University College of Dentistry New York New York NY USA
| | - Sher Bahadur Poudel
- David B. Kriser Dental Center Department of Molecular Pathobiology New York University College of Dentistry New York New York NY USA
| | - Leeann D. Louis
- Department of Biomedical Engineering City College of New York New York NY USA
| | - Andrzej Bartke
- Southern Illinois University School of Medicine Springfield IL USA
| | | | - John J. Kopchick
- Edison Biotechnology Institute and Dept. of Biomedical Sciences Ohio University Athens OH USA
| | - Shoshana Yakar
- David B. Kriser Dental Center Department of Molecular Pathobiology New York University College of Dentistry New York New York NY USA
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Sulaiman SZS, Tan WM, Radzi R, Shafie INF, Ajat M, Mansor R, Mohamed S, Ng AMH, Lau SF. Comparison of bone and articular cartilage changes in osteoarthritis: a micro-computed tomography and histological study of surgically and chemically induced osteoarthritic rabbit models. J Orthop Surg Res 2021; 16:663. [PMID: 34749769 PMCID: PMC8577030 DOI: 10.1186/s13018-021-02781-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 10/06/2021] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND Osteoarthritis (OA) is a multifaceted condition that affects both the subchondral bones and the articular cartilage. Animal models are widely used as an effective supplement and simulation for human OA studies in investigating disease mechanisms and pathophysiology. This study is aimed to evaluate the temporal changes of bone and cartilage in surgically and chemically induced osteoarthritis using micro-computed tomography and histology. METHODS Thirty rabbits underwent either anterior cruciate ligament transection (ACLT) procedure or injected intraarticularly with monosodium iodoacetate (MIA, 8 mg) at the right knee joint. The subchondral bones were scanned via micro-CT, and articular cartilage was assessed histologically at 4-, 8- and 12-week post-induction. RESULTS Based on bone micro-architecture parameters, the surgically induced group revealed bone remodelling processes, indicated by increase bone volume, thickening of trabeculae, reduced trabecular separation and reduced porosity. On the other hand, the chemically induced group showed active bone resorption processes depicted by decrease bone volume, thinning of trabeculae, increased separation of trabecular and increased porosity consistently until week 12. Histologically, the chemically induced group showed more severe articular cartilage damage compared to the surgically induced group. CONCLUSIONS It can be concluded that in the ACLT group, subchondral bone remodelling precedes articular cartilage damage and vice versa in the MIA group. The findings revealed distinct pathogenic pathways for both induction methods, providing insight into tailored therapeutic strategies, as well as disease progression and treatment outcomes monitoring.
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Affiliation(s)
- Sharifah Zakiah Syed Sulaiman
- Department of Veterinary Clinical Studies, Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia
| | - Wei Miao Tan
- Department of Veterinary Clinical Studies, Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia
| | - Rozanaliza Radzi
- Department of Veterinary Clinical Studies, Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia
| | - Intan Nur Fatiha Shafie
- Department of Veterinary Clinical Studies, Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia
| | - Mokrish Ajat
- Department of Veterinary Preclinical Studies, Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia
| | - Rozaihan Mansor
- Department of Farm and Exotic Animals Medicine and Surgery, Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia
| | - Suhaila Mohamed
- UPM-Makna Cancer Research Laboratory (CANRES), Institute of Bioscience, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia
| | - Angela Min Hwei Ng
- Tissue Engineering Centre, Universiti Kebangsaan Malaysia Medical Centre, 56000, Cheras, Kuala Lumpur, Malaysia
| | - Seng Fong Lau
- Department of Veterinary Clinical Studies, Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia.
- UPM-Makna Cancer Research Laboratory (CANRES), Institute of Bioscience, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia.
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Peng CH, Lin WY, Yeh KT, Chen IH, Wu WT, Lin MD. The molecular etiology and treatment of glucocorticoid-induced osteoporosis. Tzu Chi Med J 2021; 33:212-223. [PMID: 34386357 PMCID: PMC8323641 DOI: 10.4103/tcmj.tcmj_233_20] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 11/19/2020] [Accepted: 12/30/2020] [Indexed: 12/30/2022] Open
Abstract
Glucocorticoid-induced osteoporosis (GIOP) is the most common form of secondary osteoporosis, accounting for 20% of osteoporosis diagnoses. Using glucocorticoids for >6 months leads to osteoporosis in 50% of patients, resulting in an increased risk of fracture and death. Osteoblasts, osteocytes, and osteoclasts work together to maintain bone homeostasis. When bone formation and resorption are out of balance, abnormalities in bone structure or function may occur. Excess glucocorticoids disrupt the bone homeostasis by promoting osteoclast formation and prolonging osteoclasts' lifespan, leading to an increase in bone resorption. On the other hand, glucocorticoids inhibit osteoblasts' formation and facilitate apoptosis of osteoblasts and osteocytes, resulting in a reduction of bone formation. Several signaling pathways, signaling modulators, endocrines, and cytokines are involved in the molecular etiology of GIOP. Clinically, adults ≥40 years of age using glucocorticoids chronically with a high fracture risk are considered to have medical intervention. In addition to vitamin D and calcium tablet supplementations, the major therapeutic options approved for GIOP treatment include antiresorption drug bisphosphonates, parathyroid hormone N-terminal fragment teriparatide, and the monoclonal antibody denosumab. The selective estrogen receptor modulator can only be used under specific condition for postmenopausal women who have GIOP but fail to the regular GIOP treatment or have specific therapeutic contraindications. In this review, we focus on the molecular etiology of GIOP and the molecular pharmacology of the therapeutic drugs used for GIOP treatment.
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Affiliation(s)
- Cheng-Huan Peng
- Department of Orthopedics, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien, Taiwan.,Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan.,School of Medicine, Tzu Chi University, Hualien, Taiwan
| | - Wen-Ying Lin
- Department of Orthopedics, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien, Taiwan
| | - Kuang-Ting Yeh
- Department of Orthopedics, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien, Taiwan.,School of Medicine, Tzu Chi University, Hualien, Taiwan
| | - Ing-Ho Chen
- Department of Orthopedics, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien, Taiwan.,School of Medicine, Tzu Chi University, Hualien, Taiwan
| | - Wen-Tien Wu
- Department of Orthopedics, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien, Taiwan.,Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan.,School of Medicine, Tzu Chi University, Hualien, Taiwan
| | - Ming-Der Lin
- Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan.,Department of Molecular Biology and Human Genetics, Tzu Chi University, Hualien, Taiwan
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da Silva Sasso GR, Florencio-Silva R, Sasso-Cerri E, Gil CD, de Jesus Simões M, Cerri PS. Spatio-temporal immunolocalization of VEGF-A, Runx2, and osterix during the early steps of intramembranous ossification of the alveolar process in rat embryos. Dev Biol 2021; 478:133-143. [PMID: 34245724 DOI: 10.1016/j.ydbio.2021.07.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Revised: 06/10/2021] [Accepted: 07/03/2021] [Indexed: 12/14/2022]
Abstract
Vascular endothelial growth factor A (VEGF-A) is expressed by several cell types and is a crucial factor for angiogenic-osteogenic coupling. However, the immunolocalization of VEGF-A during the early stages of the alveolar process formation remains underexplored. Thus, we analyzed the spatio-temporal immunolocalization of VEGF-A and its relationship with Runt-related transcription factor 2 (Runx2) and osterix (Osx) during the early steps of intramembranous ossification of the alveolar process in rat embryos. Embryo heads (E) of 16, 18 and 20-day-old rats were processed for paraffin embedding. Histomorphometry and immunohistochemistry to detect VEGF-A, Runx2, and Osx (osteoblast differentiation markers) were performed. The volume density of bone tissue including bone cells and blood vessels increased significantly in E18 and E20. Cells showing high VEGF-A immunoreactivity were initially observed within a perivascular niche in the ectomesenchyme; afterwards, these cells were diffusely located near bone formation sites. Runx2-and Osx-immunopositive cells were observed in corresponded regions of cells showing strong VEGF-A immunoreactivity. Although these immunostained cells were observed in all specimens, this immunolocalization pattern was more evident in E16 specimens and gradually decreased in E18 and E20 specimens. Double immunofluorescence labelling showed intracellular co-localization of Osx and VEGF-A in cells surrounding the developing alveolar process, indicating a crucial role of VEGF-A in osteoblast differentiation. Our results showed VEGF-A immunoexpression in osteoblasts and its precursors during the maxillary alveolar process formation of rat embryos. Moreover, the VEGF-A-positive cells located within a perivascular niche at the early stages of the alveolar process development suggest a crosstalk between endothelium and ectomesenchymal cells, reinforcing the angiogenic-osteogenic coupling in this process.
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Affiliation(s)
- Gisela Rodrigues da Silva Sasso
- Universidade Federal de São Paulo - UNIFESP, Escola Paulista de Medicina - EPM, Departamento de Morfologia e Genética, Disciplina de Histologia e Biologia Estrutural, São Paulo, SP, Brazil; Universidade Federal de São Paulo - UNIFESP, Escola Paulista de Medicina - EPM, Departamento de Ginecologia, São Paulo, SP, Brazil
| | - Rinaldo Florencio-Silva
- Universidade Federal de São Paulo - UNIFESP, Escola Paulista de Medicina - EPM, Departamento de Morfologia e Genética, Disciplina de Histologia e Biologia Estrutural, São Paulo, SP, Brazil
| | - Estela Sasso-Cerri
- São Paulo State University (UNESP), School of Dentistry, Araraquara - Department of Morphology, Genetics, Orthodontics and Pediatric Dentistry - Laboratory of Histology and Embryology, Araraquara, SP, Brazil
| | - Cristiane Damas Gil
- Universidade Federal de São Paulo - UNIFESP, Escola Paulista de Medicina - EPM, Departamento de Morfologia e Genética, Disciplina de Histologia e Biologia Estrutural, São Paulo, SP, Brazil
| | - Manuel de Jesus Simões
- Universidade Federal de São Paulo - UNIFESP, Escola Paulista de Medicina - EPM, Departamento de Morfologia e Genética, Disciplina de Histologia e Biologia Estrutural, São Paulo, SP, Brazil
| | - Paulo Sérgio Cerri
- São Paulo State University (UNESP), School of Dentistry, Araraquara - Department of Morphology, Genetics, Orthodontics and Pediatric Dentistry - Laboratory of Histology and Embryology, Araraquara, SP, Brazil.
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A single-cell analytical approach to quantify activated caspase-3/7 during osteoblast proliferation, differentiation, and apoptosis. Anal Bioanal Chem 2021; 413:5085-5093. [PMID: 34169347 DOI: 10.1007/s00216-021-03471-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 05/27/2021] [Accepted: 06/09/2021] [Indexed: 10/21/2022]
Abstract
The protein heterogeneity at the single-cell level has been recognized to be vital for an understanding of various life processes during animal development. In addition, the knowledge of accurate quantity of relevant proteins at cellular level is essential for appropriate interpretation of diagnostic and therapeutic results. Some low-copy-number proteins are known to play a crucial role during cell proliferation, differentiation, and also in apoptosis. The fate decision is often based on the concentration of these proteins in the individual cells. This is likely to apply also for caspases, cysteine proteases traditionally associated with cell death via apoptosis but recently being discovered also as important factors in cell proliferation and differentiation. The hypothesis was tested in bone-related cells, where modulation of fate from apoptosis to proliferation/differentiation and vice versa is particularly challenging, e.g., towards anti-osteoporotic treatments and anti-cancer strategies. An ultrasensitive and highly selective method based on bioluminescence photon counting was used to quantify activated caspase-3/7 in order to demonstrate protein-level heterogeneity in individual cells within one population and to associate quantitative measurements with different cell fates (proliferation, differentiation, apoptosis). The results indicate a gradual increase of caspase-3/7 activation from the proliferative status to differentiation (more than three times) and towards apoptosis (more than six times). The findings clearly support one of the putative key mechanisms of non-apoptotic functions of pro-apoptotic caspases based on fine-tuning of their activation levels.
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Phlpp1 is induced by estrogen in osteoclasts and its loss in Ctsk-expressing cells does not protect against ovariectomy-induced bone loss. PLoS One 2021; 16:e0251732. [PMID: 34143773 PMCID: PMC8213150 DOI: 10.1371/journal.pone.0251732] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 05/02/2021] [Indexed: 11/19/2022] Open
Abstract
Prior studies demonstrated that deletion of the protein phosphatase Phlpp1 in Ctsk-Cre expressing cells enhances bone mass, characterized by diminished osteoclast activity and increased coupling to bone formation. Due to non-specific expression of Ctsk-Cre, the definitive mechanism for this observation was unclear. To further define the role of bone resorbing osteoclasts, we performed ovariectomy (Ovx) and Sham surgeries on Phlpp1 cKOCtsk and WT mice. Micro-CT analyses confirmed enhanced bone mass of Phlpp1 cKOCtsk Sham females. In contrast, Ovx induced bone loss in both groups, with no difference between Phlpp1 cKOCtsk and WT mice. Histomorphometry demonstrated that Ovx mice lacked differences in osteoclasts per bone surface, suggesting that estradiol (E2) is required for Phlpp1 deficiency to have an effect. We performed high throughput unbiased transcriptional profiling of Phlpp1 cKOCtsk osteoclasts and identified 290 differentially expressed genes. By cross-referencing these differentially expressed genes with all estrogen response element (ERE) containing genes, we identified IGFBP4 as potential estrogen-dependent target of Phlpp1. E2 induced PHLPP1 expression, but reduced IGFBP4 levels. Moreover, genetic deletion or chemical inhibition of Phlpp1 was correlated with IGFBP4 levels. We then assessed IGFBP4 expression by osteoclasts in vivo within intact 12-week-old females. Modest IGFBP4 immunohistochemical staining of TRAP+ osteoclasts within WT females was observed. In contrast, TRAP+ bone lining cells within intact Phlpp1 cKOCtsk females robustly expressed IGFBP4, but levels were diminished within TRAP+ bone lining cells following Ovx. These results demonstrate that effects of Phlpp1 conditional deficiency are lost following Ovx, potentially due to estrogen-dependent regulation of IGFBP4.
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Osteocyte Dysfunction in Joint Homeostasis and Osteoarthritis. Int J Mol Sci 2021; 22:ijms22126522. [PMID: 34204587 PMCID: PMC8233862 DOI: 10.3390/ijms22126522] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 06/13/2021] [Accepted: 06/16/2021] [Indexed: 01/29/2023] Open
Abstract
Structural disturbances of the subchondral bone are a hallmark of osteoarthritis (OA), including sclerotic changes, cystic lesions, and osteophyte formation. Osteocytes act as mechanosensory units for the micro-cracks in response to mechanical loading. Once stimulated, osteocytes initiate the reparative process by recruiting bone-resorbing cells and bone-forming cells to maintain bone homeostasis. Osteocyte-expressed sclerostin is known as a negative regulator of bone formation through Wnt signaling and the RANKL pathway. In this review, we will summarize current understandings of osteocytes at the crossroad of allometry and mechanobiology to exploit the relationship between osteocyte morphology and function in the context of joint aging and osteoarthritis. We also aimed to summarize the osteocyte dysfunction and its link with structural and functional disturbances of the osteoarthritic subchondral bone at the molecular level. Compared with normal bones, the osteoarthritic subchondral bone is characterized by a higher bone volume fraction, a larger trabecular bone number in the load-bearing region, and an increase in thickness of pre-existing trabeculae. This may relate to the aberrant expressions of sclerostin, periostin, dentin matrix protein 1, matrix extracellular phosphoglycoprotein, insulin-like growth factor 1, and transforming growth factor-beta, among others. The number of osteocyte lacunae embedded in OA bone is also significantly higher, yet the volume of individual lacuna is relatively smaller, which could suggest abnormal metabolism in association with allometry. The remarkably lower percentage of sclerostin-positive osteocytes, together with clustering of Runx-2 positive pre-osteoblasts, may suggest altered regulation of osteoblast differentiation and osteoblast-osteocyte transformation affected by both signaling molecules and the extracellular matrix. Aberrant osteocyte morphology and function, along with anomalies in molecular signaling mechanisms, might explain in part, if not all, the pre-osteoblast clustering and the uncoupled bone remodeling in OA subchondral bone.
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Ngoc Thuy Tran V, Chaisuparat R. Medication-related osteonecrosis of the jaw: Osteoclast profile in comparison with osteoradionecrosis of the jaw and osteomyelitis of the jaw. J Oral Pathol Med 2021; 50:731-740. [PMID: 34038006 DOI: 10.1111/jop.13202] [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: 03/10/2021] [Revised: 04/29/2021] [Accepted: 05/13/2021] [Indexed: 11/28/2022]
Abstract
BACKGROUND Medication-related osteonecrosis of the jaw (MRONJ) is a pathology condition of jaw bone caused by a side effect of medications prescribed for skeletal disease. The mechanism of MRONJ is still unknown now. Osteoclasts are cells directly influenced by the medication and the modification in cells metabolisms by the drugs lead to MRONJ. Thus, this study aimed to investigate the osteoclasts morphology, quantity, and comparing with other necrotic diseases. METHODS Thirty-eight (38) subjects, including cases with MRONJ (n = 11), osteoradionecrosis of the jaw (n = 9), osteomyelitis of the jaw (n = 9), and normal jaw bone (n = 9), were studied. Hematoxylin-and-eosin-stained slides of these diagnosed cases were used to evaluate osteoclasts' characteristics. Immunohistochemistry of TRAP was performed to observed the function of osteoclasts. These characteristics of osteoclasts were also evaluated in the relationship with the histological features using regression analysis. RESULTS The results showed that osteoclasts in MRONJ enhance activity by increasing the size and the quantity (p < 0.05). The presence of osteoblasts, inflammatory cells, and bacterial colonies showed a strong correlation with the change in morphology and the number of osteoclasts (p < 0.05). However, the TRAP-positive mean number and the TRAP intensity of osteoclasts in MRONJ did not show a significant difference with those in other groups (p > 0.05). CONCLUSION In conclusion, osteoclasts in MRONJ increase the number and become bigger with multi-nuclei which might relate to the presence of osteoblasts, inflammation, and microorganisms. This finding supports the idea osteoclasts might be the main key to investigate MRONJ.
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Affiliation(s)
- Vy Ngoc Thuy Tran
- Graduate Program in Oral Biology, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand
| | - Risa Chaisuparat
- Department of Oral Pathology, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand
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Designing Hydrogel-Based Bone-On-Chips for Personalized Medicine. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11104495] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The recent development of bone-on-chips (BOCs) holds the main advantage of requiring a low quantity of cells and material, compared to traditional In Vitro models. By incorporating hydrogels within BOCs, the culture system moved to a three dimensional culture environment for cells which is more representative of bone tissue matrix and function. The fundamental components of hydrogel-based BOCs, namely the cellular sources, the hydrogel and the culture chamber, have been tuned to mimic the hematopoietic niche in the bone aspirate marrow, cancer bone metastasis and osteo/chondrogenic differentiation. In this review, we examine the entire process of developing hydrogel-based BOCs to model In Vitro a patient specific situation. First, we provide bone biological understanding for BOCs design and then how hydrogel structural and mechanical properties can be tuned to meet those requirements. This is followed by a review on hydrogel-based BOCs, developed in the last 10 years, in terms of culture chamber design, hydrogel and cell source used. Finally, we provide guidelines for the definition of personalized pathological and physiological bone microenvironments. This review covers the information on bone, hydrogel and BOC that are required to develop personalized therapies for bone disease, by recreating clinically relevant scenarii in miniaturized devices.
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Li MCM, Chow SKH, Wong RMY, Qin L, Cheung WH. The role of osteocytes-specific molecular mechanism in regulation of mechanotransduction - A systematic review. J Orthop Translat 2021; 29:1-9. [PMID: 34036041 PMCID: PMC8138679 DOI: 10.1016/j.jot.2021.04.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 03/15/2021] [Accepted: 04/11/2021] [Indexed: 11/29/2022] Open
Abstract
Background Osteocytes, composing over 90% of bone cells, are well known for their mechanosensing abilities. Aged osteocytes with impaired morphology and function are less efficient in mechanotransduction which will disrupt bone turnover leading to osteoporosis. The aim of this systematic review is to delineate the mechanotransduction mechanism at different stages in order to explore potential target for therapeutic drugs. Methods A systematic literature search was performed in PubMed and Web of Science. Original animal, cell and clinical studies with available English full-text were included. Information was extracted from the included studies for review. Results The 26 studies included in this review provided evidence that mechanical loading are sensed by osteocytes via various sensing proteins and transduced to different signaling molecules which later initiate various biochemical responses. Studies have shown that osteocyte plasma membrane and cytoskeletons are emerging key players in initiating mechanotransduction. Bone regulating genes expressions are altered in response to load sensed by osteocytes, but the genes involved different signaling pathways and the spatiotemporal expression pattern had made mechanotransduction mechanism complicated. Most of the included studies described the important role of osteocytes in pathways that regulate mechanosensing and bone remodeling. Conclusions This systematic review provides an up-to-date insight to different steps of mechanotransduction. A better understanding of the mechanotransduction mechanism is beneficial in search of new potential treatment for osteoporotic patients. By delineating the unique morphology of osteocytes and their interconnected signaling network new targets can be discovered for drug development. Translational potential of this article This systematic review provides an up-to-date sequential overview and highlights the different osteocyte-related pathways and signaling molecules during mechanotransduction. This allows a better understanding of mechanotransduction for future development of new therapeutic interventions to treat patients with impaired mechanosensitivity.
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Affiliation(s)
- Meng Chen Michelle Li
- Musculoskeletal Research Laboratory, Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Hong Kong, China
| | - Simon Kwoon Ho Chow
- Musculoskeletal Research Laboratory, Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Hong Kong, China
- The CUHK-ACC Space Medicine Centre on Health Maintenance of Musculoskeletal System, The Chinese University of Hong Kong Shenzhen Research Institute, Shenzhen, PR China
| | - Ronald Man Yeung Wong
- Musculoskeletal Research Laboratory, Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Hong Kong, China
| | - Ling Qin
- Musculoskeletal Research Laboratory, Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Hong Kong, China
| | - Wing Hoi Cheung
- Musculoskeletal Research Laboratory, Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Hong Kong, China
- The CUHK-ACC Space Medicine Centre on Health Maintenance of Musculoskeletal System, The Chinese University of Hong Kong Shenzhen Research Institute, Shenzhen, PR China
- Corresponding author.Department of Orthopaedics and Traumatology, 5/F, Clinical Sciences Building, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China.
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Hu W, Chen Y, Dou C, Dong S. Microenvironment in subchondral bone: predominant regulator for the treatment of osteoarthritis. Ann Rheum Dis 2021; 80:413-422. [PMID: 33158879 PMCID: PMC7958096 DOI: 10.1136/annrheumdis-2020-218089] [Citation(s) in RCA: 171] [Impact Index Per Article: 57.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Revised: 10/21/2020] [Accepted: 10/22/2020] [Indexed: 12/11/2022]
Abstract
Osteoarthritis (OA) is a degenerative joint disease in the elderly. Although OA has been considered as primarily a disease of the articular cartilage, the participation of subchondral bone in the pathogenesis of OA has attracted increasing attention. This review summarises the microstructural and histopathological changes in subchondral bone during OA progression that are due, at the cellular level, to changes in the interactions among osteocytes, osteoblasts, osteoclasts (OCs), endothelial cells and sensory neurons. Therefore, we focus on how pathological cellular interactions in the subchondral bone microenvironment promote subchondral bone destruction at different stages of OA progression. In addition, the limited amount of research on the communication between OCs in subchondral bone and chondrocytes (CCs) in articular cartilage during OA progression is reviewed. We propose the concept of 'OC-CC crosstalk' and describe the various pathways by which the two cell types might interact. Based on the 'OC-CC crosstalk', we elaborate potential therapeutic strategies for the treatment of OA, including restoring abnormal subchondral bone remodelling and blocking the bridge-subchondral type H vessels. Finally, the review summarises the current understanding of how the subchondral bone microenvironment is related to OA pain and describes potential interventions to reduce OA pain by targeting the subchondral bone microenvironment.
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Affiliation(s)
- Wenhui Hu
- Department of Biomedical Materials Science, Third Military Medical University, Chongqing, China
| | - Yueqi Chen
- Department of Biomedical Materials Science, Third Military Medical University, Chongqing, China
- Department of Orthopedics, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Ce Dou
- Department of Biomedical Materials Science, Third Military Medical University, Chongqing, China
- Department of Orthopedics, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Shiwu Dong
- Department of Biomedical Materials Science, Third Military Medical University, Chongqing, China
- Department of Orthopedics, Southwest Hospital, Third Military Medical University, Chongqing, China
- State Key Laboratory of Trauma, Burns and Combined Injury, Third Military Medical University, Chongqing, China
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Coffman AA, Basta-Pljakic J, Guerra RM, Ebetino FH, Lundy MW, Majeska RJ, Schaffler MB. A Bisphosphonate With a Low Hydroxyapatite Binding Affinity Prevents Bone Loss in Mice After Ovariectomy and Reverses Rapidly With Treatment Cessation. JBMR Plus 2021; 5:e10476. [PMID: 33869992 PMCID: PMC8046044 DOI: 10.1002/jbm4.10476] [Citation(s) in RCA: 3] [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: 01/13/2021] [Accepted: 02/04/2021] [Indexed: 12/30/2022] Open
Abstract
Bisphosphonates (BPs) are a mainstay of osteoporosis treatment; however, concerns about bone health based on oversuppression of remodeling remain. Long‐term bone remodeling suppression adversely affects bone material properties with microdamage accumulation and reduced fracture toughness in animals and increases in matrix mineralization and atypical femur fractures in patients. Although a “drug holiday” from BPs to restore remodeling and improve bone quality seems reasonable, clinical BPs have long functional half‐lives because of their high hydroxyapatite (HAP) binding affinities. This places a practical limit on the reversibility and effectiveness of a drug holiday. BPs with low HAP affinity and strong osteoclast inhibition potentially offer an alternative approach; their antiresorptive effect should reverse rapidly when dosing is discontinued. This study tested this concept using NE‐58025, a BP with low HAP affinity and moderate osteoclast inhibition potential. Young adult female C57Bl/6 mice were ovariectomized (OVX) and treated with NE‐58025, risedronate, or PBS vehicle for 3 months to test effectiveness in preventing long‐term bone loss. Bone microarchitecture, histomorphometry, and whole‐bone mechanical properties were assessed. To test reversibility, OVX mice were similarly treated for 3 months, treatment was stopped, and bone was assessed up to 3 months post‐treatment. NE‐58025 and RIS inhibited long‐term OVX‐induced bone loss, but NE‐58025 antiresorptive effects were more pronounced. Withdrawing NE‐58025 treatment led to the rapid onset of trabecular resorption with a 200% increase in osteoclast surface and bone loss within 1 month. Cessation of risedronate treatment did not lead to increases in resorption indices or bone loss. These results show that NE‐58025 prevents OVX‐induced bone loss, and its effects reverse quickly following cessation treatment in vivo. Low‐HAP affinity BPs may have use as reversible, antiresorptive agents with a rapid on/off profile, which may be useful for maintaining bone health with long‐term BP treatment. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.
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Affiliation(s)
- Abigail A Coffman
- Department of Biomedical Engineering The City College of New York New York NY USA
| | - Jelena Basta-Pljakic
- Department of Biomedical Engineering The City College of New York New York NY USA
| | - Rosa M Guerra
- Department of Biomedical Engineering The City College of New York New York NY USA
| | - Frank H Ebetino
- Department of Chemistry University of Rochester Rochester NY USA.,BioVinc, LLC Pasadena CA USA
| | - Mark W Lundy
- BioVinc, LLC Pasadena CA USA.,Department of Anatomy and Cell Biology Indiana University Indianapolis IN USA
| | - Robert J Majeska
- Department of Biomedical Engineering The City College of New York New York NY USA
| | - Mitchell B Schaffler
- Department of Biomedical Engineering The City College of New York New York NY USA
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Osumi R, Wang Z, Ishihara Y, Odagaki N, Iimura T, Kamioka H. Changes in the intra- and peri-cellular sclerostin distribution in lacuno-canalicular system induced by mechanical unloading. J Bone Miner Metab 2021; 39:148-159. [PMID: 32844318 DOI: 10.1007/s00774-020-01135-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 07/26/2020] [Indexed: 10/23/2022]
Abstract
INTRODUCTION Mechanical stimuli regulate Sclerostin (Scl), a negative regulator of bone formation, expression in osteocytes. However, the detailed Scl distribution in osteocytes in response to mechanical unloading remains unclear. MATERIALS AND METHODS Twelve-week-old male rats were used. The sciatic and femoral nerves on the right side were excised as mechanical unloading treatment. A sham operation was performed on the left side. One week after neurotrauma, the bone density of the femora was evaluated by peripheral quantitative computed tomography, and immunofluorescence was performed in coronal sections of the femoral diaphysis. The mean fluorescence intensity and fluorescent profile of Scl from the marrow to the periosteal side were analyzed to estimate the Scl expression and determine to which side (marrow or periosteal) the Scl prefers to distribute in response to mechanical unloading. The most sensitive region indicated by the immunofluorescence results was further investigated by transmission electron microscopy (TEM) with immunogold staining to show the Scl expression changes in different subcellular structures. RESULTS In femur distal metaphysis, neurotrauma-induced mechanical unloading significantly decreased the bone density, made the distribution of Scl closer to the marrow on the anterior and medial side, and increased the Scl expression only on the lateral side. TEM findings showed that only the expression of Scl in canaliculi was increased by mechanical unloading. CONCLUSIONS Our results showed that even short-term mechanical unloading is enough to decrease bone density, and mechanical unloading not only regulated the Scl expression but also changed the Scl distribution in both the osteocyte network and subcellular structures.
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Affiliation(s)
- Ryuta Osumi
- Department of Orthodontics, Okayama University Hospital, Okayama, Japan
| | - Ziyi Wang
- Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Okayama, Okayama, 700-8558, Japan
- Research Fellow of Japan Society for the Promotion of Science, Tokyo, Japan
| | | | - Naoya Odagaki
- Department of Orthodontics, Okayama University Hospital, Okayama, Japan
| | - Tadahiro Iimura
- Department of Pharmacology, Graduate School of Dental Medicine, Hokkaido University, Hokkaido, Japan
| | - Hiroshi Kamioka
- Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Okayama, Okayama, 700-8558, Japan.
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Shan Z, Zhao Y, Qiu Z, Angxiu S, Gu Y, Luo J, Bi H, Luo W, Xiong R, Ma S, He Z, Chen L. Conjugated linoleic acid prompts bone formation in ovariectomized osteoporotic rats and weakens osteoclast formation after treatment with ultraviolet B. ANNALS OF TRANSLATIONAL MEDICINE 2021; 9:503. [PMID: 33850900 PMCID: PMC8039685 DOI: 10.21037/atm-21-934] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Background Ultraviolet B (UVB) has been reported to prevent bone loss by promoting the synthesis of vitamin D. However, UVB can also enhance osteoclastic differentiation, inhibit osteogenic differentiation, and cause oxidative damage. The present study aimed to analyze the osteoprotective effects of UVB and conjugated linoleic acid (CLA) in rats with ovariectomy-induced osteoporosis, and to determine the interactions between UVB and CLA and their effects on bone mesenchymal stem cells (BMSCs) and bone marrow mononuclear cells (BMMCs). Methods In vitro, the distance of UVB irradiation and the dose of CLA were selected by immunofluorescence assays and Cytotoxicity assay. BMSCs and BMMCs were detected by immunohistochemical and immunofluorescence assays. In vivo, three-month-old female Sprague-Dawley rats that had undergone ovariectomy were treated with UVB and CLA. After 8 weeks of therapy, the femurs of the rats were examined by micro-computed tomography (CT) and immunohistochemical detection to assess the therapeutic efficacy. Results The least inhibitive UVB distance and dosage of CLA were selected for the in vivo experiments. CLA effectively weakened the osteogenic inhibitory effect of UVB (72 cm), significantly improved the activity of alkaline phosphatase (ALP), promoted the formation of mineralized nodules, and alleviated the oxidative damage induced by UVB. CLA also effectively weakened the osteoclast-promoting effect of UVB (72 cm), inhibited osteoclast formation, and inhibited the inflammatory damage to BMMCs caused by UVB (72 cm) irradiation. Micro-CT results showed that UVB irradiation could promote bone formation in ovariectomized Sprague-Dawley rats, while CLA could significantly promote bone regeneration. Immunofluorescence assays results showed that CLA alleviated UVB-induced oxidative damage to osteoblasts. The ROS detection results demonstrated that CLA effectively alleviated UVB-induced oxidative damage to BMSCs. Furthermore, Immunohistochemical assays showed that UVB and CLA treatment increased bone density, inhibited osteolytic osteolysis, and enhanced osteogenic activity. Conclusions CLA can effectively weaken osteoclast promotion, osteogenic inhibition, and oxidative damage caused by UVB. Combination treatment of UVB and CLA exerts an osteoprotective effect on ovariectomized osteoporotic rats and stimulates osteogenesis. The molecular mechanism of this interaction requires further investigation.
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Affiliation(s)
- Zhongshu Shan
- Department of Orthopedic Surgery, the 1st Affiliated Hospital of Soochow University, Suzhou, China.,Department of Orthopedic Surgery, People's Hospital of Qinghai Province, Xining, China
| | - Yanyan Zhao
- Department of Orthopedic Surgery, People's Hospital of Qinghai Province, Xining, China
| | - Zhixue Qiu
- Department of Orthopedic Surgery, People's Hospital of Qinghai Province, Xining, China
| | - Suonan Angxiu
- Department of Orthopedic Surgery, People's Hospital of Qinghai Province, Xining, China
| | - Yong Gu
- Department of Orthopedic Surgery, the 1st Affiliated Hospital of Soochow University, Suzhou, China
| | - Junming Luo
- Department of Pathology, People's Hospital of Qinghai Province, Xining, China
| | - Hongtao Bi
- Qinghai Provincial Key Laboratory of Tibetan Medicine Pharmacology and Safety Evaluation, Northwest Institute of Plateau Biology, Chinese Academy of Sciences; Xining, China
| | - Wei Luo
- Department of Endocrinology, People's Hospital of Qinghai Province, Xining, China
| | - Rui Xiong
- Nutrition Department, People's Hospital of Qinghai Province, Xining, China
| | - Siqing Ma
- Department of Critical Care Medicine, People's Hospital of Qinghai Province, Xining, China
| | - Zhao He
- Department of Orthopedic Surgery, People's Hospital of Qinghai Province, Xining, China
| | - Liang Chen
- Department of Orthopedic Surgery, the 1st Affiliated Hospital of Soochow University, Suzhou, China
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Abstract
Glucocorticoids are widely prescribed to treat various allergic and autoimmune diseases; however, long-term use results in glucocorticoid-induced osteoporosis, characterized by consistent changes in bone remodeling with decreased bone formation as well as increased bone resorption. Not only bone mass but also bone quality decrease, resulting in an increased incidence of fractures. The primary role of autophagy is to clear up damaged cellular components such as long-lived proteins and organelles, thus participating in the conservation of different cells. Apoptosis is the physiological death of cells, and plays a crucial role in the stability of the environment inside a tissue. Available basic and clinical studies indicate that autophagy and apoptosis induced by glucocorticoids can regulate bone metabolism through complex mechanisms. In this review, we summarize the relationship between apoptosis, autophagy and bone metabolism related to glucocorticoids, providing a theoretical basis for therapeutic targets to rescue bone mass and bone quality in glucocorticoid-induced osteoporosis.
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He Z, Li H, Han X, Zhou F, Du J, Yang Y, Xu Q, Zhang S, Zhang S, Zhao N, Yan M, Yu Z. Irisin inhibits osteocyte apoptosis by activating the Erk signaling pathway in vitro and attenuates ALCT-induced osteoarthritis in mice. Bone 2020; 141:115573. [PMID: 32768686 DOI: 10.1016/j.bone.2020.115573] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 07/20/2020] [Accepted: 07/26/2020] [Indexed: 01/29/2023]
Abstract
Moderate exercise can alleviate symptoms of osteoarthritis (OA) such as pain, stiffness, and joint deformities that are associated with progressive cartilaginous degeneration, osteophyte formation, subchondral bone changes, and synovial inflammation. Irisin is an exercise-related myokine that reportedly plays a crucial role in bone remodeling. However, its role in OA remains unknown. This study aimed to determine whether irisin can attenuate OA progression and the mechanism of its therapeutic effect. Three-month-old male C57BL/6J mice were randomized to groups that underwent sham operation, and anterior cruciate ligament transection (ACLT) intraperitoneally injected with vehicle or irisin in vivo. Apoptosis was induced by stretching murine osteocyte-like MLO-Y4 cells in vitro. Irisin reduced wear, maintained the proportion of hyaline cartilage, a more complete cartilage structure, and lower Osteoarthritis Research Society International (OARSI) scores at 4 weeks after ACLT. Irisin reduced the expression of matrix metalloproteinase (MMP)-13 in cartilage and caspase 3 in the subchondral bone. Irisin exerted rescue effects in microstructural parameters of subchondral trabecular bone including bone volume fraction (BV/TV), trabecular number (Tb.N), connection density (Conn. D), and the structure model index (SMI) compared with ACLT-vehicle group. Bone histomorphometry showed that irisin increased subchondral bone remodeling. The decreasing ratio (%) of the eroded surface (ES/BS) was reversed by irisin in the ACLT+vehicle group. Staining with tartrate-resistant acid phosphatase showed a decreased number of osteoclasts. Irisin significantly increased the proliferation of osteocytes, protected them from apoptosis, and maintained cellular activity by regulating the expression of Bax, Bcl-2, and osteoprotegerin/receptor activator of nuclear factor (NF)-kB-ligand (OPG/Rankl). Irisin activated serine/threonine-selective protein kinases (Erk) and p38 signaling, and its anti-apoptosis function depended on the Erk signaling pathway. Irisin attenuated OA progression by decreasing osteocyte apoptosis and improving the microarchitecture of subchondral bone. Activation of the Erk pathway by irisin plays an important role in reducing osteocyte apoptosis in vitro.
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Affiliation(s)
- Zihao He
- Shanghai Key Laboratory of Orthopedic Implant, Department of Orthopedics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China
| | - Hanjun Li
- Shanghai Key Laboratory of Orthopedic Implant, Department of Orthopedics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China
| | - Xuequan Han
- Shanghai Key Laboratory of Orthopedic Implant, Department of Orthopedics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China
| | - Feng Zhou
- Shanghai Key Laboratory of Orthopedic Implant, Department of Orthopedics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China
| | - Jingke Du
- Shanghai Key Laboratory of Orthopedic Implant, Department of Orthopedics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China
| | - Yiqi Yang
- Shanghai Key Laboratory of Orthopedic Implant, Department of Orthopedics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China
| | - Qi Xu
- Shanghai Key Laboratory of Orthopedic Implant, Department of Orthopedics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China
| | - Shuhong Zhang
- Shanghai Key Laboratory of Orthopedic Implant, Department of Orthopedics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China
| | - Shuangyan Zhang
- Shanghai Key Laboratory of Orthopedic Implant, Department of Orthopedics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China
| | - Ning Zhao
- Department of Orthodontics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China
| | - Mengning Yan
- Shanghai Key Laboratory of Orthopedic Implant, Department of Orthopedics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China.
| | - Zhifeng Yu
- Shanghai Key Laboratory of Orthopedic Implant, Department of Orthopedics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China.
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Yang J, Dong D, Luo X, Zhou J, Shang P, Zhang H. Iron Overload-Induced Osteocyte Apoptosis Stimulates Osteoclast Differentiation Through Increasing Osteocytic RANKL Production In Vitro. Calcif Tissue Int 2020; 107:499-509. [PMID: 32995951 DOI: 10.1007/s00223-020-00735-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 07/21/2020] [Indexed: 12/23/2022]
Abstract
Iron overload is closely associated with osteoporosis, the potential cellular mechanism involved in decreased osteoblast differentiation and increased osteoclast formation. However, the effect of iron overload on the biological behavior in osteocytes has not been reported. This study aims to investigate the changes of osteocytic activity, apoptosis, and its regulation on osteoclastogenesis in response to iron overload. MLO-Y4 osteocyte-like cells and primary osteocytes from mice were processed with ferric ammonium citrate (FAC) and deferoxamine (DFO), the conditioned medium (CM) was harvested and co-cultured with Raw264.7 cells and bone marrow-derived macrophages (BMDMs) to induce them to differentiate into osteoclasts. Osteocyte apoptosis, osteoclast differentiation, osteocytic gene expression and protein secretion of receptor activator of nuclear factor κB ligand (RANKL) and osteoprotegerin (OPG) was examined. Excessive iron has a toxic effect on MLO-Y4 osteocyte-like cells. Increased cell apoptosis in MLO-Y4 cells and primary osteocytes was induced by iron overload. The osteoclastic formation, differentiation-related gene expression, and osteoclastic bone-resorption capability were significantly increased after treated with the CM from iron overload-exposed osteocytes. Excessive iron exposure significantly promoted the gene expression and protein secretion of the RANKL in MLO-Y4 cells. Addition of RANKL-blocking antibody completely abolished the increase of osteoclast formation and bone resorption capacity induced by the CM from osteocytes exposed to excessive iron. Moreover, the pan-caspase apoptosis inhibitor, QVD (quinolyl-valyl-O-methylaspartyl-[-2,6-difluorophenoxy]-methylketone) was used to inhibit osteocyte apoptosis. The results showed osteocyte apoptosis induced by iron overload was reduced by QVD and accompanied by the decrease of soluble RANKL (sRANKL) in supernatant. The increase of osteoclast formation and bone resorption capacity induced by the CM from osteocytes exposed to excessive iron was significantly decreased by QVD. These results indicated that iron overload-induced osteocyte apoptosis is required to regulate osteoclast differentiation by increasing osteocytic RANKL production. This study, for the first time, reveals the indirect effect of iron overload on osteoclast differentiation through regulating osteocytes.
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Affiliation(s)
- Jiancheng Yang
- Department of Spine Surgery, People's Hospital of Longhua, Affiliated Hospital of Southern Medical University, No. 38, Jinglong Construction Road, Shenzhen, 518109, Guangdong, China
- Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, 127 West Youyi Road, Beilin District, Xi'an, 710072, Shaanxi, China
| | - Dandan Dong
- Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, 127 West Youyi Road, Beilin District, Xi'an, 710072, Shaanxi, China
| | - Xinle Luo
- Department of Spine Surgery, People's Hospital of Longhua, Affiliated Hospital of Southern Medical University, No. 38, Jinglong Construction Road, Shenzhen, 518109, Guangdong, China
- The Third School of Clinical Medicine, Southern Medical University, Shenzhen, China
| | - Jianhua Zhou
- Department of Spine Surgery, People's Hospital of Longhua, Affiliated Hospital of Southern Medical University, No. 38, Jinglong Construction Road, Shenzhen, 518109, Guangdong, China
| | - Peng Shang
- Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, 127 West Youyi Road, Beilin District, Xi'an, 710072, Shaanxi, China.
- Research & Development Institute of Northwestern Polytechnical University in Shenzhen, Shenzhen, China.
| | - Hao Zhang
- Department of Spine Surgery, People's Hospital of Longhua, Affiliated Hospital of Southern Medical University, No. 38, Jinglong Construction Road, Shenzhen, 518109, Guangdong, China.
- The Third School of Clinical Medicine, Southern Medical University, Shenzhen, China.
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Osteocyte Vegf-a contributes to myeloma-associated angiogenesis and is regulated by Fgf23. Sci Rep 2020; 10:17319. [PMID: 33057033 PMCID: PMC7560700 DOI: 10.1038/s41598-020-74352-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 09/16/2020] [Indexed: 12/12/2022] Open
Abstract
Multiple Myeloma (MM) induces bone destruction, decreases bone formation, and increases marrow angiogenesis in patients. We reported that osteocytes (Ocys) directly interact with MM cells to increase tumor growth and expression of Ocy-derived factors that promote bone resorption and suppress bone formation. However, the contribution of Ocys to enhanced marrow vascularization in MM is unclear. Since the MM microenvironment is hypoxic, we assessed if hypoxia and/or interactions with MM cells increases pro-angiogenic signaling in Ocys. Hypoxia and/or co-culture with MM cells significantly increased Vegf-a expression in MLOA5-Ocys, and conditioned media (CM) from MLOA5s or MM-MLOA5 co-cultured in hypoxia, significantly increased endothelial tube length compared to normoxic CM. Further, Vegf-a knockdown in MLOA5s or primary Ocys co-cultured with MM cells or neutralizing Vegf-a in MM-Ocy co-culture CM completely blocked the increased endothelial activity. Importantly, Vegf-a-expressing Ocy numbers were significantly increased in MM-injected mouse bones, positively correlating with tumor vessel area. Finally, we demonstrate that direct contact with MM cells increases Ocy Fgf23, which enhanced Vegf-a expression in Ocys. Fgf23 deletion in Ocys blocked these changes. These results suggest hypoxia and MM cells induce a pro-angiogenic phenotype in Ocys via Fgf23 and Vegf-a signaling, which can promote MM-induced marrow vascularization.
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