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Yang M, Zhu L. Osteoimmunology: The Crosstalk between T Cells, B Cells, and Osteoclasts in Rheumatoid Arthritis. Int J Mol Sci 2024; 25:2688. [PMID: 38473934 DOI: 10.3390/ijms25052688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2024] [Revised: 02/22/2024] [Accepted: 02/24/2024] [Indexed: 03/14/2024] Open
Abstract
Rheumatoid arthritis (RA) is an ongoing inflammatory condition that affects the joints and can lead to severe damage to cartilage and bones, resulting in significant disability. This condition occurs when the immune system becomes overactive, causing osteoclasts, cells responsible for breaking down bone, to become more active than necessary, leading to bone breakdown. RA disrupts the equilibrium between osteoclasts and osteoblasts, resulting in serious complications such as localized bone erosion, weakened bones surrounding the joints, and even widespread osteoporosis. Antibodies against the receptor activator of nuclear factor-κB ligand (RANKL), a crucial stimulator of osteoclast differentiation, have shown great effectiveness both in laboratory settings and actual patient cases. Researchers are increasingly focusing on osteoclasts as significant contributors to bone erosion in RA. Given that RA involves an overactive immune system, T cells and B cells play a pivotal role by intensifying the immune response. The imbalance between Th17 cells and Treg cells, premature aging of T cells, and excessive production of antibodies by B cells not only exacerbate inflammation but also accelerate bone destruction. Understanding the connection between the immune system and osteoclasts is crucial for comprehending the impact of RA on bone health. By delving into the immune mechanisms that lead to joint damage, exploring the interactions between the immune system and osteoclasts, and investigating new biomarkers for RA, we can significantly improve early diagnosis, treatment, and prognosis of this condition.
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Affiliation(s)
- Mei Yang
- Department of Pharmacology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, Beijing 100005, China
- Medical Epigenetics Research Center, Chinese Academy of Medical Sciences, Beijing 100005, China
| | - Lei Zhu
- Department of Pharmacology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, Beijing 100005, China
- Medical Epigenetics Research Center, Chinese Academy of Medical Sciences, Beijing 100005, China
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2
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Xu J, Yu L, Liu F, Wan L, Deng Z. The effect of cytokines on osteoblasts and osteoclasts in bone remodeling in osteoporosis: a review. Front Immunol 2023; 14:1222129. [PMID: 37475866 PMCID: PMC10355373 DOI: 10.3389/fimmu.2023.1222129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2023] [Accepted: 06/12/2023] [Indexed: 07/22/2023] Open
Abstract
The complicated connections and cross talk between the skeletal system and the immune system are attracting more attention, which is developing into the field of Osteoimmunology. In this field, cytokines that are among osteoblasts and osteoclasts play a critical role in bone remodeling, which is a pathological process in the pathogenesis and development of osteoporosis. Those cytokines include the tumor necrosis factor (TNF) family, the interleukin (IL) family, interferon (IFN), chemokines, and so on, most of which influence the bone microenvironment, osteoblasts, and osteoclasts. This review summarizes the effect of cytokines on osteoblasts and osteoclasts in bone remodeling in osteoporosis, aiming to providing the latest reference to the role of immunology in osteoporosis.
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Affiliation(s)
- Jie Xu
- Department of Orthopedics, Renmin Hospital of Wuhan University, Wuhan, China
| | - Linxin Yu
- Renmin Hospital of Wuhan University, Wuhan, China
| | - Feng Liu
- Department of Orthopedics, Renmin Hospital of Wuhan University, Wuhan, China
| | - Longbiao Wan
- Department of Orthopedics, Renmin Hospital of Wuhan University, Wuhan, China
| | - Zhenhua Deng
- Hubei Provincial Hospital of Traditional Chinese Medicine (TCM), Wuhan, China
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3
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Wong L, McMahon LP. Crosstalk between bone and muscle in chronic kidney disease. Front Endocrinol (Lausanne) 2023; 14:1146868. [PMID: 37033253 PMCID: PMC10076741 DOI: 10.3389/fendo.2023.1146868] [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: 01/18/2023] [Accepted: 03/14/2023] [Indexed: 04/11/2023] Open
Abstract
With increasing life expectancy, the related disorders of bone loss, metabolic dysregulation and sarcopenia have become major health threats to the elderly. Each of these conditions is prevalent in patients with chronic kidney disease (CKD), particularly in more advanced stages. Our current understanding of the bone-muscle interaction is beyond mechanical coupling, where bone and muscle have been identified as interrelated secretory organs, and regulation of both bone and muscle metabolism occurs through osteokines and myokines via autocrine, paracrine and endocrine systems. This review appraises the current knowledge regarding biochemical crosstalk between bone and muscle, and considers recent progress related to the role of osteokines and myokines in CKD, including modulatory effects of physical exercise and potential therapeutic targets to improve musculoskeletal health in CKD patients.
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Affiliation(s)
- Limy Wong
- Department of Renal Medicine, Monash University Eastern Health Clinical School, Box Hill, VIC, Australia
- Department of Renal Medicine, Eastern Health, Box Hill, VIC, Australia
- *Correspondence: Limy Wong,
| | - Lawrence P. McMahon
- Department of Renal Medicine, Monash University Eastern Health Clinical School, Box Hill, VIC, Australia
- Department of Renal Medicine, Eastern Health, Box Hill, VIC, Australia
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4
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Iwamoto N, Kawakami A. The monocyte-to-osteoclast transition in rheumatoid arthritis: Recent findings. Front Immunol 2022; 13:998554. [PMID: 36172385 PMCID: PMC9510592 DOI: 10.3389/fimmu.2022.998554] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 08/24/2022] [Indexed: 11/13/2022] Open
Abstract
Rheumatoid arthritis (RA) is an autoimmune disease characterized by joint inflammation leading to joint destruction and deformity. The crucial role of osteoclasts in the bone erosion in RA has been demonstrated. Deregulated osteoclastogenesis which is affected by environmental factors including the inflammatory state, as well as genetic and epigenetic factors, is one of hallmarks of RA pathogenesis. An enhanced-monocyte-to-osteoclast transition plays an important role in osteoclast upregulation in RA because under specific stimuli, circulating monocytes might migrate to a specific location in the bones and fuse with each other to become mature multinucleated osteoclasts. To understand the mechanism of bone damage in RA and to develop novel treatments targeting osteoclast upregulation, it is important to clarify our understanding of the monocyte-to-osteoclast transition in RA. Several potential targets which inhibit both inflammation and osteoclastogenesis, as well as regulators that affect the monocyte-to-osteoclast transition have been revealed by recent studies. Here, we review the factors affecting osteoclastogenesis in RA, summarize the anti-osteoclastogenic effects of current RA treatments, and identify promising therapeutic targets relating to both inflammation and osteoclastogenesis.
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Maeda K, Yoshida K, Nishizawa T, Otani K, Yamashita Y, Okabe H, Hadano Y, Kayama T, Kurosaka D, Saito M. Inflammation and Bone Metabolism in Rheumatoid Arthritis: Molecular Mechanisms of Joint Destruction and Pharmacological Treatments. Int J Mol Sci 2022; 23:ijms23052871. [PMID: 35270012 PMCID: PMC8911191 DOI: 10.3390/ijms23052871] [Citation(s) in RCA: 41] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 02/28/2022] [Accepted: 03/02/2022] [Indexed: 12/31/2022] Open
Abstract
Rheumatoid arthritis (RA) is an inflammatory disease characterized by a variety of symptoms and pathologies often presenting with polyarthritis. The primary symptom in the initial stage is joint swelling due to synovitis. With disease progression, cartilage and bone are affected to cause joint deformities. Advanced osteoarticular destruction and deformation can cause irreversible physical disabilities. Physical disabilities not only deteriorate patients’ quality of life but also have substantial medical economic effects on society. Therefore, prevention of the progression of osteoarticular destruction and deformation is an important task. Recent studies have progressively improved our understanding of the molecular mechanism by which synovitis caused by immune disorders results in activation of osteoclasts; activated osteoclasts in turn cause bone destruction and para-articular osteoporosis. In this paper, we review the mechanisms of bone metabolism under physiological and RA conditions, and we describe the effects of therapeutic intervention against RA on bone.
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Affiliation(s)
- Kazuhiro Maeda
- Department of Orthopaedic Surgery, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-ku, Tokyo 105-8461, Japan; (T.N.); (Y.Y.); (H.O.); (Y.H.); (T.K.); (M.S.)
- Correspondence: ; Tel.: +81-3-3433-1111
| | - Ken Yoshida
- Division of Rheumatology, Department of Internal Medicine, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-ku, Tokyo 105-8461, Japan; (K.Y.); (K.O.); (D.K.)
| | - Tetsuro Nishizawa
- Department of Orthopaedic Surgery, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-ku, Tokyo 105-8461, Japan; (T.N.); (Y.Y.); (H.O.); (Y.H.); (T.K.); (M.S.)
| | - Kazuhiro Otani
- Division of Rheumatology, Department of Internal Medicine, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-ku, Tokyo 105-8461, Japan; (K.Y.); (K.O.); (D.K.)
| | - Yu Yamashita
- Department of Orthopaedic Surgery, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-ku, Tokyo 105-8461, Japan; (T.N.); (Y.Y.); (H.O.); (Y.H.); (T.K.); (M.S.)
| | - Hinako Okabe
- Department of Orthopaedic Surgery, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-ku, Tokyo 105-8461, Japan; (T.N.); (Y.Y.); (H.O.); (Y.H.); (T.K.); (M.S.)
| | - Yuka Hadano
- Department of Orthopaedic Surgery, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-ku, Tokyo 105-8461, Japan; (T.N.); (Y.Y.); (H.O.); (Y.H.); (T.K.); (M.S.)
| | - Tomohiro Kayama
- Department of Orthopaedic Surgery, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-ku, Tokyo 105-8461, Japan; (T.N.); (Y.Y.); (H.O.); (Y.H.); (T.K.); (M.S.)
| | - Daitaro Kurosaka
- Division of Rheumatology, Department of Internal Medicine, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-ku, Tokyo 105-8461, Japan; (K.Y.); (K.O.); (D.K.)
| | - Mitsuru Saito
- Department of Orthopaedic Surgery, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-ku, Tokyo 105-8461, Japan; (T.N.); (Y.Y.); (H.O.); (Y.H.); (T.K.); (M.S.)
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Jenkins RH, Hughes STO, Figueras AC, Jones SA. Unravelling the broader complexity of IL-6 involvement in health and disease. Cytokine 2021; 148:155684. [PMID: 34411990 DOI: 10.1016/j.cyto.2021.155684] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 07/20/2021] [Accepted: 08/04/2021] [Indexed: 02/07/2023]
Abstract
The classification of interleukin-6 (IL-6) as a pro-inflammatory cytokine undervalues the biological impact of this cytokine in health and disease. With broad activities affecting the immune system, tissue homeostasis and metabolic processes, IL-6 displays complex biology. The significance of these involvements has become increasingly important in clinical settings where IL-6 is identified as a prominent target for therapy. Here, clinical experience with IL-6 antagonists emphasises the need to understand the context-dependent properties of IL-6 within an inflammatory environment and the anticipated or unexpected consequences of IL-6 blockade. In this review, we will describe the immunobiology of IL-6 and explore the gamut of IL-6 bioactivity affecting the clinical response to biological drugs targeting this cytokine pathway.
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Affiliation(s)
- Robert H Jenkins
- Division of Infection & Immunity, The School of Medicine, Cardiff University, Cardiff, Wales, UK; Systems Immunity Research Institute, The School of Medicine, Cardiff University, Cardiff, Wales, UK
| | - Stuart T O Hughes
- Division of Infection & Immunity, The School of Medicine, Cardiff University, Cardiff, Wales, UK; Systems Immunity Research Institute, The School of Medicine, Cardiff University, Cardiff, Wales, UK
| | - Ana Cardus Figueras
- Division of Infection & Immunity, The School of Medicine, Cardiff University, Cardiff, Wales, UK; Systems Immunity Research Institute, The School of Medicine, Cardiff University, Cardiff, Wales, UK
| | - Simon A Jones
- Division of Infection & Immunity, The School of Medicine, Cardiff University, Cardiff, Wales, UK; Systems Immunity Research Institute, The School of Medicine, Cardiff University, Cardiff, Wales, UK.
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7
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Takeuchi T, Yoshida H, Tanaka S. Role of interleukin-6 in bone destruction and bone repair in rheumatoid arthritis. Autoimmun Rev 2021; 20:102884. [PMID: 34229044 DOI: 10.1016/j.autrev.2021.102884] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 05/10/2021] [Indexed: 12/14/2022]
Abstract
Rheumatoid arthritis (RA) is a common inflammatory form of arthritis leading to the progressive bone and joint destruction. Many factors are closely involved in the pathology of RA, in particular bone-related cells and inflammatory cytokines such as TNF-α and interleukin-6 (IL-6). Because RA patients with progressive bone destruction experience accelerated deterioration of their quality of life, inhibition of disease progression and joint destruction has become an important clinical goal. Recent studies have also found that drug intervention targeting proinflammatory cytokines such as IL-6 results in bone repair in addition to suppression of bone and joint destruction, and these results suggest the potential for new therapeutic goals. Regarding the relationship between IL-6 and bone destruction, essential roles of osteoclasts have been reported over many years; however, more recent studies have explored the relationship of IL-6 with osteoblasts and osteocytes. In this review, we highlight the perspectives of basic and clinical research, adding new findings on the relationships between IL-6 and bone-related cells associated with inflammation, and the possibility of bone repair by blocking IL-6.
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Affiliation(s)
- Tsutomu Takeuchi
- Division of Rheumatology, Department of Internal Medicine, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, Japan
| | - Hiroto Yoshida
- Chugai Pharmaceutical Co. Ltd., 200 Kajiwara, Kamakura City, Kanagawa, Japan
| | - Sakae Tanaka
- Department of Orthopaedic Surgery, Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.
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8
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von Kaeppler EP, Wang Q, Raghu H, Bloom MS, Wong H, Robinson WH. Interleukin 4 promotes anti-inflammatory macrophages that clear cartilage debris and inhibits osteoclast development to protect against osteoarthritis. Clin Immunol 2021; 229:108784. [PMID: 34126239 DOI: 10.1016/j.clim.2021.108784] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 06/08/2021] [Accepted: 06/09/2021] [Indexed: 01/12/2023]
Abstract
OBJECTIVE Osteoarthritis (OA), the leading cause of joint failure, is characterized by breakdown of articular cartilage and remodeling of subchondral bone in synovial joints. Despite the high prevalence and debilitating effects of OA, no disease-modifying drugs exist. Increasing evidence, including genetic variants of the interleukin 4 (IL-4) and IL-4 receptor genes, implicates a role for IL-4 in OA, however, the mechanism underlying IL-4 function in OA remains unknown. Here, we investigated the role of IL-4 in OA pathogenesis. METHODS Il4-, myeloid-specific-Il4ra-, and Stat6-deficient and control mice were subjected to destabilization of the medial meniscus to induce OA. Macrophages, osteoclasts, and synovial explants were stimulated with IL-4 in vitro, and their function and expression profiles characterized. RESULTS Mice lacking IL-4, IL-4Ra in myeloid cells, or STAT6 developed exacerbated cartilage damage and osteophyte formation relative to WT controls. In vitro analyses revealed that IL-4 downregulates osteoarthritis-associated genes, enhances macrophage phagocytosis of cartilage debris, and inhibits osteoclast differentiation and activation via the type I receptor. CONCLUSION Our findings demonstrate that IL-4 protects against osteoarthritis in a myeloid and STAT6-dependent manner. Further, IL-4 can promote an immunomodulatory microenvironment in which joint-resident macrophages polarize towards an M2 phenotype and efficiently clear pro-inflammatory debris, and osteoclasts maintain a homeostatic level of activity in subchondral bone. These findings support a role for IL-4 modulation of myeloid cell types in maintenance of joint health and identify a pathway that could provide therapeutic benefit for osteoarthritis.
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Affiliation(s)
- Ericka P von Kaeppler
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Stanford, CA, United States of America; VA Palo Alto Health Care System, Palo Alto, CA, United States of America
| | - Qian Wang
- VA Palo Alto Health Care System, Palo Alto, CA, United States of America; Division of Immunology and Rheumatology, Stanford University, Stanford, CA, United States of America
| | - Harini Raghu
- VA Palo Alto Health Care System, Palo Alto, CA, United States of America; Division of Immunology and Rheumatology, Stanford University, Stanford, CA, United States of America
| | - Michelle S Bloom
- VA Palo Alto Health Care System, Palo Alto, CA, United States of America; Division of Immunology and Rheumatology, Stanford University, Stanford, CA, United States of America
| | - Heidi Wong
- VA Palo Alto Health Care System, Palo Alto, CA, United States of America; Division of Immunology and Rheumatology, Stanford University, Stanford, CA, United States of America
| | - William H Robinson
- VA Palo Alto Health Care System, Palo Alto, CA, United States of America; Division of Immunology and Rheumatology, Stanford University, Stanford, CA, United States of America.
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Abstract
Cytokines and hematopoietic growth factors have traditionally been thought of as regulators of the development and function of immune and blood cells. However, an ever-expanding number of these factors have been discovered to have major effects on bone cells and the development of the skeleton in health and disease (Table 1). In addition, several cytokines have been directly linked to the development of osteoporosis in both animal models and in patients. In order to understand the mechanisms regulating bone cells and how this may be dysregulated in disease states, it is necessary to appreciate the diverse effects that cytokines and inflammation have on osteoblasts, osteoclasts, and bone mass. This chapter provides a broad overview of this topic with extensive references so that, if desired, readers can access specific references to delve into individual topics in greater detail.
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Affiliation(s)
- Joseph Lorenzo
- Departments of Medicine and Orthopaedic Surgery, UConn Health, Farmington, CT, USA.
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10
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George EL, Truesdell SL, Magyar AL, Saunders MM. The effects of mechanically loaded osteocytes and inflammation on bone remodeling in a bisphosphonate-induced environment. Bone 2019; 127:460-473. [PMID: 31301402 DOI: 10.1016/j.bone.2019.07.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 07/03/2019] [Accepted: 07/08/2019] [Indexed: 12/23/2022]
Abstract
Bisphosphonate-related osteonecrosis of the jaw is a disease appearing after tooth removal in patients undergoing bisphosphonate treatment for metastasizing cancers and osteoporosis. The complexity of the condition requires a multicellular model to address the net effects of two key risk factors: mechanical trauma (pathologic overload) and inflammation. In this work, a system comprised of a polydimethylsiloxane chip and mechanical loading device is used to expose bisphosphonate-treated osteocytes to mechanical trauma. Specifically, osteocytes are treated with the potent nitrogen-containing bisphosphonate, zoledronic acid, and exposed to short-term pathologic overload via substrate stretch. During bone remodeling, osteocyte apoptosis plays a role in attracting pre-osteoclasts to sites of damage; as such, lactate dehydrogenase activity, cell death and protein expression are evaluated as functions of load. Additionally, the effects of osteocyte soluble factors on osteoclast and osteoblast functional activity are quantified. Osteoclast activity and bone resorption are quantified in the presence and absence of inflammatory components, lipopolysaccharide and interferon gamma. Results suggest that inflammation associated with bacterial infection may hinder bone resorption by osteoclasts. In addition, osteocytes may respond to overload by altering expression of soluble signals that act on osteoblasts to attenuate bone formation. These findings give insight into the multicellular interactions implicated in bisphosphonate-related osteonecrosis of the jaw.
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Affiliation(s)
- Estee L George
- The University of Akron, Olson Research Center 319, 302 E. Buchtel Ave., Akron, OH 44325-0302, USA.
| | - Sharon L Truesdell
- The University of Akron, Olson Research Center 319, 302 E. Buchtel Ave., Akron, OH 44325-0302, USA.
| | - Alexandria L Magyar
- The University of Akron, Olson Research Center 319, 302 E. Buchtel Ave., Akron, OH 44325-0302, USA.
| | - Marnie M Saunders
- The University of Akron, Olson Research Center 319, 302 E. Buchtel Ave., Akron, OH 44325-0302, USA.
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Smith JK. IL-6 and the dysregulation of immune, bone, muscle, and metabolic homeostasis during spaceflight. NPJ Microgravity 2018; 4:24. [PMID: 30534586 PMCID: PMC6279793 DOI: 10.1038/s41526-018-0057-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 10/10/2018] [Indexed: 01/08/2023] Open
Abstract
We have previously reported that exercise-related secretion of IL-6 by peripheral blood mononuclear cells is proportionate to body weight, suggesting that IL-6 is gravisensitive and that suboptimal production of this key cytokine may contribute to homeostatic dysregulations that occur during spaceflight. This review details what is known about the role of this key cytokine in innate and adaptive immunity, hematopoiesis, and in bone, muscle and metabolic homeostasis on Earth and in the microgravity of space and suggests an experimental approach to confirm or disavow the role of IL-6 in space-related dysregulations.
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Affiliation(s)
- John Kelly Smith
- Departments of Academic Affairs and Biomedical Sciences, James H. Quillen College of Medicine, East Tennessee State University, Johnson City, TN USA
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12
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Combination of IL-6 and sIL-6R differentially regulate varying levels of RANKL-induced osteoclastogenesis through NF-κB, ERK and JNK signaling pathways. Sci Rep 2017; 7:41411. [PMID: 28128332 PMCID: PMC5269740 DOI: 10.1038/srep41411] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 12/19/2016] [Indexed: 11/09/2022] Open
Abstract
Interleukin (IL)-6 is known to indirectly enhance osteoclast formation by promoting receptor activator of nuclear factor kappa-B ligand (RANKL) production by osteoblastic/stromal cells. However, little is known about the direct effect of IL-6 on osteoclastogenesis. Here, we determined the direct effects of IL-6 and its soluble receptor (sIL-6R) on RANKL-induced osteoclast formation by osteoclast precursors in vitro. We found IL-6/sIL-6R significantly promoted and suppressed osteoclast differentiation induced by low- (10 ng/ml) and high-level (50 ng/ml) RANKL, respectively. Using a bone resorption pit formation assay, expression of osteoclastic marker genes and transcription factors confirmed differential regulation of RANKL-induced osteoclastogenesis by IL-6/sIL-6R. Intracellular signaling transduction analysis revealed IL-6/sIL-6R specifically upregulated and downregulated the phosphorylation of NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells), ERK (extracellular signal-regulated kinase) and JNK (c-Jun N-terminal kinase) induced by low- and high level RANKL, respectively. Taken together, our findings demonstrate that IL-6/sIL-6R differentially regulate RANKL-induced osteoclast differentiation and activity through modulation of NF-κB, ERK and JNK signaling pathways. Thus, IL-6 likely plays a dual role in osteoclastogenesis either as a pro-resorption factor or as a protector of bone, depending on the level of RANKL within the local microenvironment.
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13
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Feng W, Liu B, Liu D, Hasegawa T, Wang W, Han X, Cui J, Yimin, Oda K, Amizuka N, Li M. Long-Term Administration of High-Fat Diet Corrects Abnormal Bone Remodeling in the Tibiae of Interleukin-6-Deficient Mice. J Histochem Cytochem 2015; 64:42-53. [PMID: 26416243 DOI: 10.1369/0022155415611931] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 09/23/2015] [Indexed: 12/19/2022] Open
Abstract
In this study, we aimed to evaluate the influence of diet-induced obesity on IL-6 deficiency-induced bone remodeling abnormality. Seven-week-old IL-6(-/-) mice and their wild type (WT) littermates were fed a standard diet (SD) or high-fat diet (HFD) for 25 weeks. Lipid formation and bone metabolism in mice tibiae were investigated by histochemical analysis. Both IL-6(-/-) and WT mice fed the HFD showed notable body weight gain, thickened cortical bones, and adipose accumulation in the bone marrow. Notably, the HFD normalized the bone phenotype of IL-6(-/-) mice to that of their WT counterpart, as characterized by a decrease in bone mass and the presence of an obliquely arranged, plate-like morphology in the trabecular bone. Alkaline phosphatase and osteocalcin expressions were attenuated in both genotypes after HFD feeding, especially for the IL-6(-/-) mice. Meanwhile, tartrate-resistant acid phosphatase staining was inhibited, osteoclast apoptosis rate down-regulated (revealed by TUNEL assay), and the proportion of cathepsin K (CK)-positive osteoclasts significantly increased in IL-6(-/-) mice on a HFD as compared with IL-6(-/-) mice on standard chow. Our results demonstrate that HFD-induced obesity reverses IL-6 deficiency-associated bone metabolic disorders by suppressing osteoblast activity, upregulating osteoclastic activity, and inhibiting osteoclast apoptosis.
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Affiliation(s)
- Wei Feng
- Department of Bone Metabolism, School of Stomatology Shandong University, Shandong Provincial Key Laboratory of Oral Tissue Regeneration, Jinan, China (WF, BL, DL, WW, XH, JC, ML)
| | - Bo Liu
- Department of Bone Metabolism, School of Stomatology Shandong University, Shandong Provincial Key Laboratory of Oral Tissue Regeneration, Jinan, China (WF, BL, DL, WW, XH, JC, ML)
| | - Di Liu
- Department of Bone Metabolism, School of Stomatology Shandong University, Shandong Provincial Key Laboratory of Oral Tissue Regeneration, Jinan, China (WF, BL, DL, WW, XH, JC, ML)
| | - Tomoka Hasegawa
- Department of Developmental Biology of Hard Tissue, Graduate School of Dental Medicine, Hokkaido University, Sapporo, Japan(TH, NA)
| | - Wei Wang
- Department of Bone Metabolism, School of Stomatology Shandong University, Shandong Provincial Key Laboratory of Oral Tissue Regeneration, Jinan, China (WF, BL, DL, WW, XH, JC, ML)
| | - Xiuchun Han
- Department of Bone Metabolism, School of Stomatology Shandong University, Shandong Provincial Key Laboratory of Oral Tissue Regeneration, Jinan, China (WF, BL, DL, WW, XH, JC, ML)
| | - Jian Cui
- Department of Bone Metabolism, School of Stomatology Shandong University, Shandong Provincial Key Laboratory of Oral Tissue Regeneration, Jinan, China (WF, BL, DL, WW, XH, JC, ML)
| | - Yimin
- Department of Advanced Medicine, Graduate School of Medicine, Hokkaido University, Sapporo, Japan (Y)
| | - Kimimitsu Oda
- Division of Biochemistry, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan (KO)
| | - Norio Amizuka
- Department of Developmental Biology of Hard Tissue, Graduate School of Dental Medicine, Hokkaido University, Sapporo, Japan(TH, NA)
| | - Minqi Li
- Department of Bone Metabolism, School of Stomatology Shandong University, Shandong Provincial Key Laboratory of Oral Tissue Regeneration, Jinan, China (WF, BL, DL, WW, XH, JC, ML)
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Huang RL, Chen G, Wang W, Herller T, Xie Y, Gu B, Li Q. Synergy between IL-6 and soluble IL-6 receptor enhances bone morphogenetic protein-2/absorbable collagen sponge-induced bone regeneration via regulation of BMPRIA distribution and degradation. Biomaterials 2015; 67:308-22. [PMID: 26232880 DOI: 10.1016/j.biomaterials.2015.07.047] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2015] [Revised: 07/22/2015] [Accepted: 07/23/2015] [Indexed: 01/13/2023]
Abstract
Bone morphogenetic protein-2/absorbable collagen sponge (BMP-2/ACS) implants have been approved for clinical use to induce bone regeneration. We previously showed that exaggerated inflammation characterized by elevated level of inflammatory cytokines including TNF-α, IL-1β, and IL-6 has been shown to inhibit BMP-2/ACS-induced bone regeneration. Furthermore, unlike the negative effects of TNF-α and IL-1β, IL-6 seemed not to affect BMP-2-induced osteoblastic differentiation of bone marrow mesenchymal stem cells (BMSCs). We hypothesized that there may be a regulatory loop between IL-6 and BMP-2 singling to affect BMP-2/ACS-induced bone regeneration. Here, we established a BMP-2/ACS-induced ectopic bone formation model in rats and fund that IL-6 injection significantly increased BMP-2/ACS-induced bone mass. Consistent with this animal model, an in vitro study demonstrated that synergy between IL-6 and soluble IL-6 receptor (IL-6/sIL-6R) promotes BMP-2-induced osteoblastic differentiation of human BMSCs through amplification of BMP/Smad signaling. Strikingly, IL-6 injection did not activate osteoclast-mediated bone resorption in the ectopic bone formation model, and IL-6/sIL-6R treatment did not affect receptor activator of NF-κB ligand (RANKL)-induced osteoclastic differentiation of human peripheral blood mononuclear cells (PBMCs) in vitro. Furthermore, IL-6/sIL-6R treatment did not affect expression of BMP receptors, but enhanced the cell surface translocation of BMP receptor IA (BMPRIA) and inhibited the degradation of BMPRIA. Collectively, these findings indicate that synergy between IL-6 and sIL-6R promotes the cell surface translocation of BMPRIA and maintains the stability of BMPRIA expression, leading to enhanced BMP-2/ACS-induced bone regeneration.
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Affiliation(s)
- Ru-Lin Huang
- Department of Plastic and Reconstructive Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, 639 Zhizaoju Road, Shanghai 200011, China
| | - Gang Chen
- Department of Plastic and Reconstructive Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, 639 Zhizaoju Road, Shanghai 200011, China
| | - Wenjin Wang
- Department of Plastic and Reconstructive Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, 639 Zhizaoju Road, Shanghai 200011, China
| | - Tanja Herller
- Department of General, Trauma, Hand, and Plastic Surgery, University of Munich, Munich, Germany
| | - Yun Xie
- Department of Plastic and Reconstructive Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, 639 Zhizaoju Road, Shanghai 200011, China
| | - Bin Gu
- Department of Plastic and Reconstructive Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, 639 Zhizaoju Road, Shanghai 200011, China
| | - Qingfeng Li
- Department of Plastic and Reconstructive Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, 639 Zhizaoju Road, Shanghai 200011, China.
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