1
|
A Low Concentration of Citreoviridin Prevents Both Intracellular Calcium Deposition in Vascular Smooth Muscle Cell and Osteoclast Activation In Vitro. Molecules 2023; 28:molecules28041693. [PMID: 36838684 PMCID: PMC9967071 DOI: 10.3390/molecules28041693] [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: 12/28/2022] [Revised: 02/01/2023] [Accepted: 02/07/2023] [Indexed: 02/12/2023] Open
Abstract
Vascular calcification (VC) and osteoporosis are age-related diseases and significant risk factors for the mortality of elderly. VC and osteoporosis may share common risk factors such as renin-angiotensin system (RAS)-related hypertension. In fact, inhibitors of RAS pathway, such as angiotensin type 1 receptor blockers (ARBs), improved both vascular calcification and hip fracture in elderly. However, a sex-dependent discrepancy in the responsiveness to ARB treatment in hip fracture was observed, possibly due to the estrogen deficiency in older women, suggesting that blocking the angiotensin signaling pathway may not be effective to suppress bone resorption, especially if an individual has underlying osteoclast activating conditions such as estrogen deficiency. Therefore, it has its own significance to find alternative modality for inhibiting both vascular calcification and osteoporosis by directly targeting osteoclast activation to circumvent the shortcoming of ARBs in preventing bone resorption in estrogen deficient individuals. In the present study, a natural compound library was screened to find chemical agents that are effective in preventing both calcium deposition in vascular smooth muscle cells (vSMCs) and activation of osteoclast using experimental methods such as Alizarin red staining and Tartrate-resistant acid phosphatase staining. According to our data, citreoviridin (CIT) has both an anti-VC effect and anti-osteoclastic effect in vSMCs and in Raw 264.7 cells, respectively, suggesting its potential as an effective therapeutic agent for both VC and osteoporosis.
Collapse
|
2
|
Zhang L, Xu L, Wang Y, Zhang X, Xue T, Sun Q, Tang H, Li M, Cao X, Shi F, Zhang G, Zhang S, Hu Z. Histone methyltransferase Setdb1 mediates osteogenic differentiation by suppressing the expression of miR-212-3p under mechanical unloading. Cell Signal 2023; 102:110554. [PMID: 36476391 DOI: 10.1016/j.cellsig.2022.110554] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 11/14/2022] [Accepted: 12/01/2022] [Indexed: 12/12/2022]
Abstract
Emerging evidence indicates that multiple mechanisms are involved in bone loss induced by mechanical unloading. Thus far, few study has established the pathophysiological role of histone modification for osteogenic differentiation under mechanical unloading. Here we demonstrated that the histone H3 lysine 9 (H3K9) methyltransferase Setdb1, which was sensitive to mechanical unloading, was increased during osteogenic differentiation of MC3T3-E1 cells for the first time. Knockdown of Setdb1 significantly blocked osteoblast function in vivo and in vitro. Through bioinformatics analysis of candidate miRNAs regulated by H3K9me3, we further identified that Setdb1 inhibited the expression of miR-212-3p by regulating the formation of H3K9me3 in the promoter region. Mechanically, we revealed that miR-212-3p was upregulated under mechanical unloading and suppressed osteogenic differentiation by directly downregulating High mobility group box 1 protein (Hmgb1) expression. Furthermore, we verified the molecular mechanism of the SETDB1/miR-212-3p/HMGB1 pathway in hFOB cells under mechanical unloading. In summary, these data demonstrate the essential function of the Setdb1/miR-212-3p/Hmgb1 pathway in osteogenic differentiation under mechanical unloading, and present a potential protective strategies against bone loss induced by mechanical unloading.
Collapse
Affiliation(s)
- Lijun Zhang
- The Key Laboratory of Aerospace Medicine, Ministry of Education, Air Force Medical University, 710032 Xi'an, Shaanxi, China
| | - Liqun Xu
- The Key Laboratory of Aerospace Medicine, Ministry of Education, Air Force Medical University, 710032 Xi'an, Shaanxi, China
| | - Yixuan Wang
- The Key Laboratory of Aerospace Medicine, Ministry of Education, Air Force Medical University, 710032 Xi'an, Shaanxi, China; Department of Gastroenterology, the 940th Hospital of Joint Logistics Support Force of Chinese PLA, 730050, Lanzhou, China
| | - Xiaoyan Zhang
- The Key Laboratory of Aerospace Medicine, Ministry of Education, Air Force Medical University, 710032 Xi'an, Shaanxi, China
| | - Tong Xue
- The Key Laboratory of Aerospace Medicine, Ministry of Education, Air Force Medical University, 710032 Xi'an, Shaanxi, China
| | - Quan Sun
- The Key Laboratory of Aerospace Medicine, Ministry of Education, Air Force Medical University, 710032 Xi'an, Shaanxi, China
| | - Hao Tang
- The Key Laboratory of Aerospace Medicine, Ministry of Education, Air Force Medical University, 710032 Xi'an, Shaanxi, China
| | - Meng Li
- The Key Laboratory of Aerospace Medicine, Ministry of Education, Air Force Medical University, 710032 Xi'an, Shaanxi, China; The Medical College of Yan'an University, 716000 Yan'an, Shaanxi, China
| | - Xinsheng Cao
- The Key Laboratory of Aerospace Medicine, Ministry of Education, Air Force Medical University, 710032 Xi'an, Shaanxi, China
| | - Fei Shi
- The Key Laboratory of Aerospace Medicine, Ministry of Education, Air Force Medical University, 710032 Xi'an, Shaanxi, China
| | - Ge Zhang
- Institute for Advancing Translational Medicine in Bone & Joint Diseases, School of Chinese Medicine, Hong Kong Baptist University, 999077, Hong Kong, China
| | - Shu Zhang
- The Key Laboratory of Aerospace Medicine, Ministry of Education, Air Force Medical University, 710032 Xi'an, Shaanxi, China.
| | - Zebing Hu
- The Key Laboratory of Aerospace Medicine, Ministry of Education, Air Force Medical University, 710032 Xi'an, Shaanxi, China.
| |
Collapse
|
3
|
Zhang T, Zhao Z, Wang T. Pulsed electromagnetic fields as a promising therapy for glucocorticoid-induced osteoporosis. Front Bioeng Biotechnol 2023; 11:1103515. [PMID: 36937753 PMCID: PMC10020513 DOI: 10.3389/fbioe.2023.1103515] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Accepted: 02/21/2023] [Indexed: 03/06/2023] Open
Abstract
Glucocorticoid-induced osteoporosis (GIOP) is considered the third type of osteoporosis and is accompanied by high morbidity and mortality. Long-term usage of glucocorticoids (GCs) causes worsened bone quality and low bone mass via their effects on bone cells. Currently, there are various clinical pharmacological treatments to regulate bone mass and skeletal health. Pulsed electromagnetic fields (PEMFs) are applied to treat patients suffering from delayed fracture healing and non-unions. PEMFs may be considered a potential and side-effect-free therapy for GIOP. PEMFs inhibit osteoclastogenesis, stimulate osteoblastogenesis, and affect the activity of bone marrow mesenchymal stem cells (BMSCs), osteocytes and blood vessels, ultimately leading to the retention of bone mass and strength. However, the underlying signaling pathways via which PEMFs influence GIOP remain unclear. This review attempts to summarize the underlying cellular mechanisms of GIOP. Furthermore, recent advances showing that PEMFs affect bone cells are discussed. Finally, we discuss the possibility of using PEMFs as therapy for GIOP.
Collapse
Affiliation(s)
- Tianxiao Zhang
- Innovation Center for Wound Repair, West China Hospital, Sichuan University, Chengdu, China
| | - Zhiliang Zhao
- Innovation Center for Wound Repair, West China Hospital, Sichuan University, Chengdu, China
| | - Tiantian Wang
- Key Laboratory of Rehabilitation Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan, China
- Institute of Rehabilitation Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan, China
- *Correspondence: Tiantian Wang,
| |
Collapse
|
4
|
Wang T, Huang S, He C. Senescent cells: A therapeutic target for osteoporosis. Cell Prolif 2022; 55:e13323. [DOI: 10.1111/cpr.13323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 07/21/2022] [Accepted: 07/25/2022] [Indexed: 11/30/2022] Open
Affiliation(s)
- Tiantian Wang
- Department of Rehabilitation Medicine, Key Laboratory of Rehabilitation Medicine, West China Hospital Sichuan University Chengdu Sichuan China
- Institute of Rehabilitation Medicine, West China Hospital Sichuan University Chengdu Sichuan China
| | - Shishu Huang
- Department of Orthopedic Surgery and Orthopedic Research Institute, West China Hospital and West China School of Medicine Sichuan University Chengdu Sichuan China
| | - Chengqi He
- Department of Rehabilitation Medicine, Key Laboratory of Rehabilitation Medicine, West China Hospital Sichuan University Chengdu Sichuan China
- Institute of Rehabilitation Medicine, West China Hospital Sichuan University Chengdu Sichuan China
| |
Collapse
|
5
|
Muire PJ, Avila JJ, Lofgren AL, Wenke JC. Neutralization of HMGB1 improves fracture healing and γδ T lymphocyte counts at the fracture site in a polytrauma rat model. J Exp Orthop 2022; 9:21. [PMID: 35229226 PMCID: PMC8885932 DOI: 10.1186/s40634-022-00453-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Accepted: 02/03/2022] [Indexed: 12/12/2022] Open
Abstract
Purpose Delayed fracture healing is a common consequence of polytrauma (PT) occurring in patients with multiple injuries. We believe that when early release of high mobility group box 1 (HMGB1) molecules from necrotic tissues exceed their normal levels in blood, they dysregulate immune responses associated with normal healing. This study investigates the detrimental effect of such dysregulate immune responses by targeting HMGB1 in a PT rat model with debilitating injuries. We hypothesized that neutralization of extracellular HMGB1 immediately post-trauma would ameliorate local immune dysregulation and improve fracture healing in a PT rat model. Methods PT rats received a single dose of either anti-rat HMGB1 polyclonal antibody (PT-Ab HMGB1) or IgY isotype (PT-IgY), were left untreated (PT-C), or had a single injury/osteotomy only (OST). Fracture healing was evaluated by micro-computed tomography (µCT) and histology at 5 weeks; and macrophages and T cell counts within the fracture site were determined with flow cytometry at 1 week. Results Notably, bone regeneration within the fracture site in PT-Ab HMGB1 rats was improved with comparable connective tissue organization than PT-C rats. Further, only γδTCR+ T cells, but not macrophages and CD4+ and CD8+ T cells, were diminished at the fracture site in PT-C and PT-IgY rats. Interestingly, the PT-Ab HMGB1 rats had increased γδTCR+ T cells compared to PT-C and PT-IgY, suggesting their potential role in regulating fracture healing. Conclusions Therefore, the initial burst of systemic HMGB1 following trauma may have a role in regulating bone regeneration via the modulation of a subclass of T cells within the fracture site, suggesting it’s importance as a therapeutic target in PT to combat immune dysregulation and delayed fracture healing. Supplementary Information The online version contains supplementary material available at 10.1186/s40634-022-00453-3.
Collapse
|
6
|
Terkawi MA, Matsumae G, Shimizu T, Takahashi D, Kadoya K, Iwasaki N. Interplay between Inflammation and Pathological Bone Resorption: Insights into Recent Mechanisms and Pathways in Related Diseases for Future Perspectives. Int J Mol Sci 2022; 23:1786. [PMID: 35163708 PMCID: PMC8836472 DOI: 10.3390/ijms23031786] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 02/01/2022] [Accepted: 02/03/2022] [Indexed: 02/01/2023] Open
Abstract
Bone is a mineralized and elastic connective tissue that provides fundamental functions in the human body, including mechanical support to the muscles and joints, protection of vital organs and storage of minerals. Bone is a metabolically active organ that undergoes continuous remodeling processes to maintain its architecture, shape, and function throughout life. One of the most important medical discoveries of recent decades has been that the immune system is involved in bone remodeling. Indeed, chronic inflammation has been recognized as the most significant factor influencing bone homeostasis, causing a shift in the bone remodeling process toward pathological bone resorption. Bone osteolytic diseases typified by excessive bone resorption account for one of the greatest causes of disability worldwide, with significant economic and public health burdens. From this perspective, we discuss the recent findings and discoveries highlighting the cellular and molecular mechanisms that regulate this process in the bone microenvironment, in addition to the current therapeutic strategies for the treatment of osteolytic bone diseases.
Collapse
Affiliation(s)
- M Alaa Terkawi
- Department of Orthopedic Surgery, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Kita-15, Nish-7, Kita-ku, Sapporo 060-8638, Japan; (G.M.); (T.S.); (D.T.); (K.K.); (N.I.)
| | - Gen Matsumae
- Department of Orthopedic Surgery, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Kita-15, Nish-7, Kita-ku, Sapporo 060-8638, Japan; (G.M.); (T.S.); (D.T.); (K.K.); (N.I.)
| | - Tomohiro Shimizu
- Department of Orthopedic Surgery, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Kita-15, Nish-7, Kita-ku, Sapporo 060-8638, Japan; (G.M.); (T.S.); (D.T.); (K.K.); (N.I.)
| | - Daisuke Takahashi
- Department of Orthopedic Surgery, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Kita-15, Nish-7, Kita-ku, Sapporo 060-8638, Japan; (G.M.); (T.S.); (D.T.); (K.K.); (N.I.)
| | - Ken Kadoya
- Department of Orthopedic Surgery, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Kita-15, Nish-7, Kita-ku, Sapporo 060-8638, Japan; (G.M.); (T.S.); (D.T.); (K.K.); (N.I.)
| | - Norimasa Iwasaki
- Department of Orthopedic Surgery, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Kita-15, Nish-7, Kita-ku, Sapporo 060-8638, Japan; (G.M.); (T.S.); (D.T.); (K.K.); (N.I.)
| |
Collapse
|
7
|
Kim HKW, Park MS, Alves do Monte F, Gokani V, Aruwajoye OO, Ren Y. Minimally Invasive Necrotic Bone Washing Improves Bone Healing After Femoral Head Ischemic Osteonecrosis: An Experimental Investigation in Immature Pigs. J Bone Joint Surg Am 2021; 103:1193-1202. [PMID: 33877059 DOI: 10.2106/jbjs.20.00578] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND Ischemic osteonecrosis of the femoral head produces necrotic cell debris and inflammatory molecules in the marrow space, which elicit a chronic inflammatory repair response. The purpose of this study was to determine the effects of flushing out the necrotic cell debris and inflammatory proteins on bone repair in a piglet model of ischemic osteonecrosis. METHODS Osteonecrosis of the femoral head of the right hindlimb was induced in 12 piglets by tying a ligature tightly around the femoral neck. One week after the surgery, 6 animals were treated with a percutaneous 3-needle bone washing procedure and non-weight-bearing (NWB) of the right hindlimb (wash group). The total saline solution wash volume was 450 mL per femoral head. Serial wash solutions were collected and analyzed. The remaining 6 animals were treated with NWB only (NWB group). At 8 weeks after the surgery, the femoral heads were assessed using radiography, micro-computed tomography (micro-CT), and histological analysis. In addition, we compared the results for these piglets with our published results for 6 piglets treated with multiple epiphyseal drilling (MED) plus NWB without bone washing (MED group). RESULTS Necrotic cells and inflammatory proteins were present in the bone wash solution collected 1 week after ischemia induction. The protein and triglyceride concentrations decreased significantly with subsequent washing (p < 0.005). At 8 weeks after ischemia induction, the wash group had a significantly higher bone volume than the MED or NWB group (p < 0.0001). Histological bone-formation measures were also significantly increased in the wash group compared with the MED group (p = 0.002) or NWB group (p < 0.0001) while macrophage numbers were significantly decreased in the wash group. CONCLUSIONS The percutaneous 3-needle procedure flushed out cell debris and inflammatory proteins from the necrotic femoral heads, decreased osteoclasts and macrophages, and increased bone formation following induction of ischemic osteonecrosis. CLINICAL RELEVANCE We believe that this is the first study to investigate the concept of washing out the necrotic femoral head to improve bone healing. The minimally invasive procedure may be useful to improve the necrotic bone environment and bone repair following ischemic osteonecrosis.
Collapse
Affiliation(s)
- Harry K W Kim
- Center for Excellence in Hip, Scottish Rite for Children, Dallas, Texas.,Department of Orthopaedic Surgery, UT Southwestern Medical Center, Dallas, Texas
| | - Min Sung Park
- Center for Excellence in Hip, Scottish Rite for Children, Dallas, Texas
| | | | - Vishal Gokani
- Center for Excellence in Hip, Scottish Rite for Children, Dallas, Texas
| | | | - Yinshi Ren
- Center for Excellence in Hip, Scottish Rite for Children, Dallas, Texas.,Department of Orthopaedic Surgery, UT Southwestern Medical Center, Dallas, Texas
| |
Collapse
|
8
|
Patil KC, Soekmadji C. Extracellular Vesicle-Mediated Bone Remodeling and Bone Metastasis: Implications in Prostate Cancer. Subcell Biochem 2021; 97:297-361. [PMID: 33779922 DOI: 10.1007/978-3-030-67171-6_12] [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] [Indexed: 02/07/2023]
Abstract
Bone metastasis is the tendency of certain primary tumors to spawn and dictate secondary neoplasia in the bone. The process of bone metastasis is regulated by the dynamic crosstalk between metastatic cancer cells, cellular components of the bone marrow microenvironment (osteoblasts, osteoclasts, and osteocytes), and the bone matrix. The feed-forward loop mechanisms governs the co-option of homeostatic bone remodeling by cancer cells in bone. Recent developments have highlighted the discovery of extracellular vesicles (EVs) and their diverse roles in distant outgrowths. Several studies have implicated EV-mediated interactions between cancer cells and the bone microenvironment in synergistically promoting pathological skeletal metabolism in the metastatic site. Nevertheless, the potential role that EVs serve in arbitrating intricate sequences of coordinated events within the bone microenvironment remains an emerging field. In this chapter, we review the role of cellular participants and molecular mechanisms in regulating normal bone physiology and explore the progress of current research into bone-derived EVs in directly triggering and coordinating the processes of physiological bone remodeling. In view of the emerging role of EVs in interorgan crosstalk, this review also highlights the multiple systemic pathophysiological processes orchestrated by the EVs to direct organotropism in bone in prostate cancer. Given the deleterious consequences of bone metastasis and its clinical importance, in-depth knowledge of the multifarious role of EVs in distant organ metastasis is expected to open new possibilities for prognostic evaluation and therapeutic intervention for advanced bone metastatic prostate cancer.
Collapse
Affiliation(s)
- Kalyani C Patil
- Translational Research Institute, Academic Health System, Hamad Medical Corporation, Doha, Qatar
| | - Carolina Soekmadji
- Department of Cell and Molecular Biology, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia. .,School of Biomedical Sciences, Faculty of Medicine, University of Queensland, Brisbane, QLD, Australia.
| |
Collapse
|
9
|
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.
Collapse
|
10
|
Osteocyte-Related Cytokines Regulate Osteoclast Formation and Bone Resorption. Int J Mol Sci 2020; 21:ijms21145169. [PMID: 32708317 PMCID: PMC7404053 DOI: 10.3390/ijms21145169] [Citation(s) in RCA: 169] [Impact Index Per Article: 42.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 07/16/2020] [Accepted: 07/20/2020] [Indexed: 01/18/2023] Open
Abstract
The process of bone remodeling is the result of the regulated balance between bone cell populations, namely bone-forming osteoblasts, bone-resorbing osteoclasts, and the osteocyte, the mechanosensory cell type. Osteoclasts derived from the hematopoietic stem cell lineage are the principal cells involved in bone resorption. In osteolytic diseases such as rheumatoid arthritis, periodontitis, and osteoporosis, the balance is lost and changes in favor of bone resorption. Therefore, it is vital to elucidate the mechanisms of osteoclast formation and bone resorption. It has been reported that osteocytes express Receptor activator of nuclear factor κΒ ligand (RANKL), an essential factor for osteoclast formation. RANKL secreted by osteocytes is the most important factor for physiologically supported osteoclast formation in the developing skeleton and in pathological bone resorption such as experimental periodontal bone loss. TNF-α directly enhances RANKL expression in osteocytes and promotes osteoclast formation. Moreover, TNF-α enhances sclerostin expression in osteocytes, which also increases osteoclast formation. These findings suggest that osteocyte-related cytokines act directly to enhance osteoclast formation and bone resorption. In this review, we outline the most recent knowledge concerning bone resorption-related cytokines and discuss the osteocyte as the master regulator of bone resorption and effector in osteoclast formation.
Collapse
|
11
|
Development of a novel minimally invasive technique to washout necrotic bone marrow content from epiphyseal bone: A preliminary cadaveric bone study. Orthop Traumatol Surg Res 2020; 106:709-715. [PMID: 32146150 DOI: 10.1016/j.otsr.2020.01.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 01/07/2020] [Accepted: 01/13/2020] [Indexed: 02/03/2023]
Abstract
INTRODUCTION Legg-Calvé-Perthes disease is a juvenile ischemic osteonecrosis which produces extensive necrotic cell debris and release of damage associated molecular patterns (DAMPs) in the femoral head. The necrotic bone environment induces a chronic inflammatory repair response with excessive bone resorption leading to deformity and early osteoarthritis. Currently there is no minimally invasive method to clear the necrotic materials from the bone to decrease the inflammatory burden of the necrotic environment and to improve the healing process. HYPOTHESIS We hypothesized that a novel minimally invasive two-needle saline washing technique would be effective to remove cell debris, proteins, and fat from the marrow space of porcine cadaveric humeral heads (HHs). MATERIALS AND METHODS Twenty-two HHs were subjected to three freeze-thaw cycles to simulate osteonecrosis prior to the wash procedure which consisted of placement of two 15-gauge intraosseous needles followed by incremental saline wash. After the washout procedure, the solutions were collected for measurements of turbidity, protein concentration, and cell count. The HHs were analyzed by optical scanning and histology. RESULTS The solution collected after each wash showed a significant decrease in the turbidity, cell count, and protein concentration (p<0.05). Histologic assessment showed significantly decreased cell debris and adipocytes in the washed group compared to the unwashed group (p<0.001). DISCUSSION/CONCLUSION The two-needle intraosseous wash technique effectively removed cell debris and proteins from the marrow space. The technique may be used to reduce the necrotic cell debris and DAMPs present in the necrotic bone. LEVEL OF EVIDENCE III, in vitro comparative study.
Collapse
|
12
|
Wang T, Yu X, He C. Pro-inflammatory Cytokines: Cellular and Molecular Drug Targets for Glucocorticoid-induced-osteoporosis via Osteocyte. Curr Drug Targets 2020; 20:1-15. [PMID: 29618305 DOI: 10.2174/1389450119666180405094046] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 03/11/2018] [Accepted: 03/21/2018] [Indexed: 02/08/2023]
Abstract
Glucocorticoids are widely used to treat varieties of allergic and autoimmune diseases, however, long-term application results in glucocorticoid-induced osteoporosis (GIOP). Inflammatory cytokines: tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) play important regulatory roles in bone metabolism, but their roles in GIOP remain largely unknown. Osteocytes can modulate the formation and function of both osteoblasts and osteoclasts, directly via gap junctions, or indirectly by transferring molecule signaling. Apoptotic osteocytes release RANKL, HMGB1 and pro-inflammatory cytokines to stimulate osteoclastogenesis. Moreover, osteocytes can secrete FGF23 to regulate bone metabolism. Exposure to high levels of GCs can drive osteocyte apoptosis and influence gap junctions, leading to bone loss. GCs treatment is regarded to produce more FGF23 to inhibit bone mineralization. GCs also disrupt the vascular to decrease osteocyte feasibility and mineral appositional rate, resulting in a decline in bone strength. Apoptotic bodies from osteocytes induced by GCs treatment can enhance production of TNF-α and IL-6. On the other hand, TNF-α and IL-6 show synergistic effects by altering osteocytes signaling towards osteoclasts and osteoblasts. In addition, TNF-α can induce osteocyte apoptosis and attribute to a worsened bone quality in GCs. IL-6 and osteocytes may interact with each other. Therefore, we hypothesize that GCs regulate osteocyteogenesis through TNF-α and IL-6, which are highly expressed around osteocyte undergoing apoptosis. In the present review, we summarized the roles of osteocytes in regulating osteoblasts and osteoclasts. Furthermore, the mechanism of GCs altered relationship between osteocytes and osteoblasts/osteoclasts. In addition, we discussed the roles of TNF-α and IL-6 in GIOP by modulating osteocytes. Lastly, we discussed the possibility of using pro-inflammatory signaling pathway as therapeutic targets to develop drugs for GIOP.
Collapse
Affiliation(s)
- Tiantian Wang
- Department of Rehabilitation Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan, 610041, China.,Key Laboratory of Rehabilitation Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan, 610041, China.,Laboratory of Endocrinology and Metabolism, Department of Endocrinology, National Key Laboratory of Biotherapy/Collaborative Innovation Center of Biotherapy and Cancer Center, West China Hospital, Sichuan University, 610041, China
| | - Xijie Yu
- Laboratory of Endocrinology and Metabolism, Department of Endocrinology, National Key Laboratory of Biotherapy/Collaborative Innovation Center of Biotherapy and Cancer Center, West China Hospital, Sichuan University, 610041, China
| | - Chengqi He
- Department of Rehabilitation Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan, 610041, China.,Key Laboratory of Rehabilitation Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan, 610041, China
| |
Collapse
|
13
|
Asadipooya K, Uy EM. Advanced Glycation End Products (AGEs), Receptor for AGEs, Diabetes, and Bone: Review of the Literature. J Endocr Soc 2019; 3:1799-1818. [PMID: 31528827 PMCID: PMC6734192 DOI: 10.1210/js.2019-00160] [Citation(s) in RCA: 110] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 07/03/2019] [Indexed: 12/24/2022] Open
Abstract
Diabetes compromises bone cell metabolism and function, resulting in increased risk of fragility fracture. Advanced glycation end products (AGEs) interact with the receptor for AGEs (RAGE) and can make a meaningful contribution to bone cell metabolism and/or alter function. Searches in PubMed using the key words "advanced glycation end-product," "RAGE," "sRAGE," "bone," and "diabetes" were made to explain some of the clinical outcomes of diabetes in bone metabolism through the AGE-RAGE signaling pathway. All published clinical studies were included in tables. The AGE-RAGE signaling pathway participates in diabetic complications, including diabetic osteopathy. Some clinical results in diabetic patients, such as reduced bone density, suppressed bone turnover markers, and bone quality impairment, could be potentially due to AGE-RAGE signaling consequences. However, the AGE-RAGE signaling pathway has some helpful roles in the bone, including an increase in osteogenic function. Soluble RAGE (sRAGE), as a ligand decoy, may increase in either conditions of RAGE production or destruction, and then it cannot always reflect the AGE-RAGE signaling. Recombinant sRAGE can block the AGE-RAGE signaling pathway but is associated with some limitations, such as accessibility to AGEs, an increase in other RAGE ligands, and a long half-life (24 hours), which is associated with losing the beneficial effect of AGE/RAGE. As a result, sRAGE is not a helpful marker to assess activity of the RAGE signaling pathway. The recombinant sRAGE cannot be translated into clinical practice due to its limitations.
Collapse
Affiliation(s)
- Kamyar Asadipooya
- Division of Endocrinology and Molecular Medicine, Department of Medicine, University of Kentucky, Lexington, Kentucky
| | - Edilfavia Mae Uy
- Division of Endocrinology and Molecular Medicine, Department of Medicine, University of Kentucky, Lexington, Kentucky
| |
Collapse
|
14
|
Davis HM, Essex AL, Valdez S, Deosthale PJ, Aref MW, Allen MR, Bonetto A, Plotkin LI. Short-term pharmacologic RAGE inhibition differentially affects bone and skeletal muscle in middle-aged mice. Bone 2019; 124:89-102. [PMID: 31028960 PMCID: PMC6543548 DOI: 10.1016/j.bone.2019.04.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 04/17/2019] [Accepted: 04/22/2019] [Indexed: 12/27/2022]
Abstract
Loss of bone and muscle mass are two major clinical complications among the growing list of chronic diseases that primarily affect elderly individuals. Persistent low-grade inflammation, one of the major drivers of aging, is also associated with both bone and muscle dysfunction in aging. Particularly, chronic activation of the receptor for advanced glycation end products (RAGE) and elevated levels of its ligands high mobility group box 1 (HMGB1), AGEs, S100 proteins and Aβ fibrils have been linked to bone and muscle loss in various pathologies. Further, genetic or pharmacologic RAGE inhibition has been shown to preserve both bone and muscle mass. However, whether short-term pharmacologic RAGE inhibition can prevent early bone and muscle loss in aging is unknown. To address this question, we treated young (4-mo) and middle-aged (15-mo) C57BL/6 female mice with vehicle or Azeliragon, a small-molecule RAGE inhibitor initially developed to treat Alzheimer's disease. Azeliragon did not prevent the aging-induced alterations in bone geometry or mechanics, likely due to its differential effects [direct vs. indirect] on bone cell viability/function. On the other hand, Azeliragon attenuated the aging-related body composition changes [fat and lean mass] and reversed the skeletal muscle alterations induced with aging. Interestingly, while Azeliragon induced similar metabolic changes in bone and skeletal muscle, aging differentially altered the expression of genes associated with glucose uptake/metabolism in these two tissues, highlighting a potential explanation for the differential effects of Azeliragon on bone and skeletal muscle in middle-aged mice. Overall, our findings suggest that while short-term pharmacologic RAGE inhibition did not protect against early aging-induced bone alterations, it prevented against the early effects of aging in skeletal muscle.
Collapse
Affiliation(s)
- Hannah M Davis
- Department of Anatomy & Cell Biology, Indiana University School of Medicine, Indianapolis, IN, United States of America; Indiana Center for Musculoskeletal Health, Indianapolis, IN, United States of America.
| | - Alyson L Essex
- Department of Anatomy & Cell Biology, Indiana University School of Medicine, Indianapolis, IN, United States of America; Indiana Center for Musculoskeletal Health, Indianapolis, IN, United States of America.
| | - Sinai Valdez
- Department of Anatomy & Cell Biology, Indiana University School of Medicine, Indianapolis, IN, United States of America.
| | - Padmini J Deosthale
- Department of Anatomy & Cell Biology, Indiana University School of Medicine, Indianapolis, IN, United States of America; Indiana Center for Musculoskeletal Health, Indianapolis, IN, United States of America.
| | - Mohammad W Aref
- Department of Anatomy & Cell Biology, Indiana University School of Medicine, Indianapolis, IN, United States of America; Indiana Center for Musculoskeletal Health, Indianapolis, IN, United States of America.
| | - Matthew R Allen
- Department of Anatomy & Cell Biology, Indiana University School of Medicine, Indianapolis, IN, United States of America; Indiana Center for Musculoskeletal Health, Indianapolis, IN, United States of America; Roudebush Veterans Administration Medical Center, Indianapolis, IN, United States of America.
| | - Andrea Bonetto
- Department of Anatomy & Cell Biology, Indiana University School of Medicine, Indianapolis, IN, United States of America; Indiana Center for Musculoskeletal Health, Indianapolis, IN, United States of America; Department of Surgery, Indiana University School of Medicine, Indianapolis, IN, United States of America.
| | - Lilian I Plotkin
- Department of Anatomy & Cell Biology, Indiana University School of Medicine, Indianapolis, IN, United States of America; Indiana Center for Musculoskeletal Health, Indianapolis, IN, United States of America; Roudebush Veterans Administration Medical Center, Indianapolis, IN, United States of America.
| |
Collapse
|
15
|
Davis HM, Valdez S, Gomez L, Malicky P, White FA, Subler MA, Windle JJ, Bidwell JP, Bruzzaniti A, Plotkin LI. High mobility group box 1 protein regulates osteoclastogenesis through direct actions on osteocytes and osteoclasts in vitro. J Cell Biochem 2019; 120:16741-16749. [PMID: 31106449 DOI: 10.1002/jcb.28932] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Accepted: 04/24/2019] [Indexed: 12/30/2022]
Abstract
Old age and Cx43 deletion in osteocytes are associated with increased osteocyte apoptosis and osteoclastogenesis. We previously demonstrated that apoptotic osteocytes release elevated concentrations of the proinflammatory cytokine, high mobility group box 1 protein (HMGB1) and apoptotic osteocyte conditioned media (CM) promotes osteoclast differentiation. Further, prevention of osteocyte apoptosis blocks osteoclast differentiation and attenuates the extracellular release of HMGB1 and RANKL. Moreover, sequestration of HMGB1, in turn, reduces RANKL production/release by MLO-Y4 osteocytic cells silenced for Cx43 (Cx43def ), highlighting the possibility that HMGB1 promotes apoptotic osteocyte-induced osteoclastogenesis. However, the role of HMGB1 signaling in osteocytes has not been well studied. Further, the mechanisms underlying its release and the receptor(s) responsible for its actions is not clear. We now report that a neutralizing HMGB1 antibody reduces osteoclast formation in RANKL/M-CSF treated bone marrow cells. In bone marrow macrophages (BMMs), toll-like receptor 4 (TLR4) inhibition with LPS-RS, but not receptor for advanced glycation end products (RAGE) inhibition with Azeliragon attenuated osteoclast differentiation. Further, inhibition of RAGE but not of TLR4 in osteoclast precursors reduced osteoclast number, suggesting that HGMB1 produced by osteoclasts directly affects differentiation by activating TLR4 in BMMs and RAGE in preosteoclasts. Our findings also suggest that increased osteoclastogenesis induced by apoptotic osteocytes CM is not mediated through HMGB1/RAGE activation and that direct HMGB1 actions in osteocytes stimulate pro-osteoclastogenic signal release from Cx43def osteocytes. Based on these findings, we propose that HMGB1 exerts dual effects on osteoclasts, directly by inducing differentiation through TLR4 and RAGE activation and indirectly by increasing pro-osteoclastogenic cytokine secretion from osteocytes.
Collapse
Affiliation(s)
- Hannah M Davis
- Department of Anatomy & Cell Biology, Indiana University School of Medicine, Indianapolis, Indiana.,Indiana Center for Musculoskeletal Health, Indianapolis, Indiana
| | - Sinai Valdez
- Department of Anatomy & Cell Biology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Leland Gomez
- Department of Anatomy & Cell Biology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Peter Malicky
- Department of Anesthesia, Indiana University School of Medicine, Indianapolis, Indiana
| | - Fletcher A White
- Department of Anesthesia, Indiana University School of Medicine, Indianapolis, Indiana.,Stark Neuroscience Research Institute, Indiana University School of Medicine, Indianapolis, Indiana.,Roudebush Veterans Administration Medical Center, Indianapolis, Indiana
| | - Mark A Subler
- Department of Human and Molecular Genetics, Virginia Commonwealth University, Richmond, Virginia
| | - Jolene J Windle
- Department of Human and Molecular Genetics, Virginia Commonwealth University, Richmond, Virginia
| | - Joseph P Bidwell
- Department of Anatomy & Cell Biology, Indiana University School of Medicine, Indianapolis, Indiana.,Indiana Center for Musculoskeletal Health, Indianapolis, Indiana
| | - Angela Bruzzaniti
- Department of Anatomy & Cell Biology, Indiana University School of Medicine, Indianapolis, Indiana.,Indiana Center for Musculoskeletal Health, Indianapolis, Indiana.,Department of Biomedical and Applied Sciences, Indiana University School of Dentistry, Indianapolis, Indiana
| | - Lilian I Plotkin
- Department of Anatomy & Cell Biology, Indiana University School of Medicine, Indianapolis, Indiana.,Indiana Center for Musculoskeletal Health, Indianapolis, Indiana.,Roudebush Veterans Administration Medical Center, Indianapolis, Indiana
| |
Collapse
|
16
|
He F, Bai J, Wang J, Zhai J, Tong L, Zhu G. Irradiation‐induced osteocyte damage promotes HMGB1‐mediated osteoclastogenesis in vitro. J Cell Physiol 2019; 234:17314-17325. [DOI: 10.1002/jcp.28351] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 01/28/2019] [Accepted: 01/30/2019] [Indexed: 01/06/2023]
Affiliation(s)
- Feilong He
- Department of Radiation Health Institute of Radiation Medicine, Fudan University Shanghai China
| | - Jiangtao Bai
- Department of Radiation Health Institute of Radiation Medicine, Fudan University Shanghai China
| | - Jianping Wang
- Department of Radiation Health Institute of Radiation Medicine, Fudan University Shanghai China
| | - Jianglong Zhai
- Department of Radiation Health Institute of Radiation Medicine, Fudan University Shanghai China
| | - Ling Tong
- Department of Radiation Health Institute of Radiation Medicine, Fudan University Shanghai China
| | - Guoying Zhu
- Department of Radiation Health Institute of Radiation Medicine, Fudan University Shanghai China
| |
Collapse
|
17
|
Abstract
PURPOSE OF REVIEW The receptor for advanced glycation end products (RAGE) and several of its ligands have been implicated in the onset and progression of pathologies associated with aging, chronic inflammation, and cellular stress. In particular, the role of RAGE and its ligands in bone tissue during both physiological and pathological conditions has been investigated. However, the extent to which RAGE signaling regulates bone homeostasis and disease onset remains unclear. Further, RAGE effects in the different bone cells and whether these effects are cell-type specific is unknown. The objective of the current review is to describe the literature over RAGE signaling in skeletal biology as well as discuss the clinical potential of RAGE as a diagnostic and/or therapeutic target in bone disease. RECENT FINDINGS The role of RAGE and its ligands during skeletal homeostasis, tissue repair, and disease onset/progression is beginning to be uncovered. For example, detrimental effects of the RAGE ligands, advanced glycation end products (AGEs), have been identified for osteoblast viability/activity, while others have observed that low level AGE exposure stimulates osteoblast autophagy, which subsequently promotes viability and function. Similar findings have been reported with HMGB1, another RAGE ligand, in which high levels of the ligand are associated with osteoblast/osteocyte apoptosis, whereas low level/short-term administration stimulates osteoblast differentiation/bone formation and promotes fracture healing. Additionally, elevated levels of several RAGE ligands (AGEs, HMGB1, S100 proteins) induce osteoblast/osteocyte apoptosis and stimulate cytokine production, which is associated with increased osteoclast differentiation/activity. Conversely, direct RAGE-ligand exposure in osteoclasts may have inhibitory effects. These observations support a conclusion that elevated bone resorption observed in conditions of high circulating ligands and RAGE expression are due to actions on osteoblasts/osteocytes rather than direct actions on osteoclasts, although additional work is required to substantiate the observations. Recent studies have demonstrated that RAGE and its ligands play an important physiological role in the regulation of skeletal development, homeostasis, and repair/regeneration. Conversely, elevated levels of RAGE and its ligands are clearly related with various diseases associated with increased bone loss and fragility. However, despite the recent advancements in the field, many questions regarding RAGE and its ligands in skeletal biology remain unanswered.
Collapse
Affiliation(s)
- Lilian I Plotkin
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, 635 Barnhill Dr., MS 5023, Indianapolis, IN, 46202, USA.
- Roudebush Veterans Administration Medical Center, Indianapolis, IN, USA.
- Indiana Center for Musculoskeletal Health, Indianapolis, IN, USA.
| | - Alyson L Essex
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, 635 Barnhill Dr., MS 5023, Indianapolis, IN, 46202, USA
- Indiana Center for Musculoskeletal Health, Indianapolis, IN, USA
| | - Hannah M Davis
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, 635 Barnhill Dr., MS 5023, Indianapolis, IN, 46202, USA
- Indiana Center for Musculoskeletal Health, Indianapolis, IN, USA
| |
Collapse
|
18
|
Metzger CE, Narayanan SA. The Role of Osteocytes in Inflammatory Bone Loss. Front Endocrinol (Lausanne) 2019; 10:285. [PMID: 31139147 PMCID: PMC6527760 DOI: 10.3389/fendo.2019.00285] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Accepted: 04/18/2019] [Indexed: 01/18/2023] Open
Abstract
Osteoimmunology investigations to-date have demonstrated the significant interactions between bone surface cells, osteoclasts and osteoblasts, and immune cells. However, there is a paucity of knowledge on osteocytes, cells embedded in the bone matrix, and their role in inflammation and inflammatory bone loss. Osteocytes communicate through various mechanisms; directly via dendritic processes and through secretion of proteins that can influence the formation and activity of osteoblasts and osteoclasts. Some osteocyte proteins (e.g., interleukin-6 and RANKL) also have roles within the immune system. In the context of mechanical loading/unloading, the regulatory role of osteocytes is well understood. More recent data on osteocytes in various inflammatory models suggest they may also aid in orchestrating inflammation-induced changes in bone turnover. In inflammatory conditions, osteocytes express multiple pro-inflammatory cytokines which are associated with increases in bone resorption and declines in bone formation. Cytokines are known to also influence cell population growth, maturation, and responsiveness via various signaling modalities, but how they influence osteocytes has not been greatly explored. Furthermore, osteocytes may play regulatory roles in orchestrating bone's response to immunological changes in inflammatory conditions. This review will address what is known about osteocyte biology in physiological conditions and in response to varying immunological conditions, as well as highlight key areas of interest for future investigations.
Collapse
Affiliation(s)
- Corinne E. Metzger
- Department of Health and Kinesiology, Texas A&M University, College Station, TX, United States
- *Correspondence: Corinne E. Metzger
| | - S. Anand Narayanan
- Department of Medical Physiology, Texas A&M Health Science Center, Bryan, TX, United States
| |
Collapse
|
19
|
van den Bosch MHJ. Inflammation in osteoarthritis: is it time to dampen the alarm(in) in this debilitating disease? Clin Exp Immunol 2018; 195:153-166. [PMID: 30421798 DOI: 10.1111/cei.13237] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/02/2018] [Indexed: 12/25/2022] Open
Abstract
Osteoarthritis (OA) is the most common joint disease that strongly reduces the quality of life in patients; However, no disease-modifying therapy is available. For a long time, OA was considered a non-inflammatory disease that was the result of 'wear-and-tear' and abnormal mechanics, and therefore many considered the term 'osteoarthritis' a misnomer. However, during the last decades the notion arose that inflammation is not only present in the majority of OA patients but, rather, actively involved in the progression of the disease. Influx of immune cells is observed in the synovium and a plethora of inflammatory mediators is present in tissues and fluids from OA patients. These mediators cause the production of degrading enzymes that break down the cartilage matrix, which is the main hallmark of OA. Alarmins, which belong to the group of danger signals, have been implicated in many inflammatory diseases. They are among the first factors to be released upon cell stress due to, for example, infection, damage and inflammation. They attract and activate cells of the immune system and therefore lie at the base of the inflammatory reaction. In this narrative review, an overview of the history of OA, the evolving concept of inflammation as important factor in the OA pathogenesis, and particularly the central role that alarmins play in the initiation and maintenance of the low-grade inflammatory response in OA, is provided. Moreover, the targeting of alarmins as a promising approach to dampen the inflammation in OA is highlighted.
Collapse
Affiliation(s)
- M H J van den Bosch
- Experimental Rheumatology, Radboud university medical center, Nijmegen, the Netherlands
| |
Collapse
|
20
|
HMBG1 as a Driver of Inflammatory and Immune Processes in the Pathogenesis of Ocular Diseases. J Ophthalmol 2018; 2018:5195290. [PMID: 30473885 PMCID: PMC6220384 DOI: 10.1155/2018/5195290] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 06/14/2018] [Accepted: 07/30/2018] [Indexed: 12/21/2022] Open
Abstract
High-mobility group box 1 (HMGB1) is a nuclear protein that can also act as an extracellular trigger of inflammation, proliferation, and migration in eye diseases. It induces signaling pathways by binding to the receptor for advanced glycation end products (RAGE) and Toll-like receptors (TLRs) 2, 4, and 9. This proinflammatory activity is considered to be important in the pathogenesis of a wide range of ocular diseases resulting from hemodynamic changes, presence of neovascular endothelial cells, secretion of intraocular immune factors or inflammation, and apoptosis of retinal cell layers. Further work is needed to elucidate in detail how HMGB1 contributes to ocular disease and how its damaging activity can be modulated. In this review, we summarize current knowledge on HMGB1 as a ligand that can evoke inflammation and immune responses in ocular diseases.
Collapse
|
21
|
Arias CF, Herrero MA, Echeverri LF, Oleaga GE, López JM. Bone remodeling: A tissue-level process emerging from cell-level molecular algorithms. PLoS One 2018; 13:e0204171. [PMID: 30231062 PMCID: PMC6145577 DOI: 10.1371/journal.pone.0204171] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 09/03/2018] [Indexed: 01/08/2023] Open
Abstract
The human skeleton undergoes constant remodeling throughout the lifetime. Processes occurring on microscopic and molecular scales degrade bone and replace it with new, fully functional tissue. Multiple bone remodeling events occur simultaneously, continuously and independently throughout the body, so that the entire skeleton is completely renewed about every ten years.Bone remodeling is performed by groups of cells called Bone Multicellular Units (BMU). BMUs consist of different cell types, some specialized in the resorption of old bone, others encharged with producing new bone to replace the former. These processes are tightly regulated so that the amount of new bone produced is in perfect equilibrium with that of old bone removed, thus maintaining bone microscopic structure.To date, many regulatory molecules involved in bone remodeling have been identified, but the precise mechanism of BMU operation remains to be fully elucidated. Given the complexity of the signaling pathways already known, one may question whether such complexity is an inherent requirement of the process or whether some subset of the multiple constituents could fulfill the essential role, leaving functional redundancy to serve an alternative safety role. We propose in this work a minimal model of BMU function that involves a limited number of signals able to account for fully functional BMU operation. Our main assumptions were i) at any given time, any cell within a BMU can select only one among a limited choice of decisions, i.e. divide, die, migrate or differentiate, ii) this decision is irreversibly determined by depletion of an appropriate internal inhibitor and iii) the dynamics of any such inhibitor are coupled to that of specific external mediators, such as hormones, cytokines, growth factors. It was thus shown that efficient BMU operation manifests as an emergent process, which results from the individual and collective decisions taken by cells within the BMU unit in the absence of any external planning.
Collapse
Affiliation(s)
- Clemente F. Arias
- Grupo Interdisciplinar de Sistemas Complejos (GISC), Universidad Complutense, 28040 Madrid, Spain
| | - Miguel A. Herrero
- Departamento de Análisis Matemático y Matemática Aplicada, Facultad de Matemáticas, Universidad Complutense, 28040 Madrid, Spain
| | - Luis F. Echeverri
- Instituto de Matemáticas, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia, 53108 Medellín, Colombia
| | - Gerardo E. Oleaga
- Departamento de Análisis Matemático y Matemática Aplicada, Facultad de Matemáticas, Universidad Complutense, 28040 Madrid, Spain
- Instituto de Matemática Interdisciplinar, Facultad de Matemáticas, Universidad Complutense, 28040 Madrid, Spain
| | - José M. López
- Departamento de Morfología y Biología Celular, Universidad de Oviedo, 33006 Oviedo, Asturias, Spain
| |
Collapse
|
22
|
miR-193a inhibits osteogenic differentiation of bone marrow-derived stroma cell via targeting HMGB1. Biochem Biophys Res Commun 2018; 503:536-543. [PMID: 29787753 DOI: 10.1016/j.bbrc.2018.05.132] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 05/18/2018] [Indexed: 11/20/2022]
Abstract
BACKGROUND miR-193a has been shown to be involved in a variety of biological processes, including cell proliferation, differentiation, and apoptosis. However, little is known about how miR-193a regulates osteogenic differentiation. METHODS We employed RT-qPCR to determine the level of miR-193a and mRNA level of HMGB1 and osteoblast-specific markers (Runx2, ALP, OSX, OCN). Besides, westernblot was used to probe protein level of phosphorylated MAPK family members and β-catenin. Bioinformatic analysis was used to predict the putative binding sequence of miR-193a to the 3'-UTR of HMGB1 and we confirmed this result by dual luciferase reporter assay. Alizarin red staining assay (ARS) and alkaline phosphatase activity (ALP) were performed to detect osteogenic differentiation. RESULTS miR-193a was downregulated in OM (osteogenic medium)induced hBMSC. More interestingly, we found that miR-193a mimic attenuated matrix mineralization and alkaline phosphatase activity, whereas miR-193a inhibitor exerted the opposite phenotypes. Mechanistically, we observed that miR-193a played an inhibitory role in expression of osteoblast-specific markers and activation of MAPK and Wnt signaling pathways. Bioinformatic analysis and dual luciferase assay demonstrated that miR-193a directly targeted 3'-UTR of HMGB1. Furthermore, we overexpressed HMGB1 in miR-193a overexpressed hBMSC to establish that HMGB1 acted as downstream target of miR-193a-inhibited osteogenic differentiation. CONCLUSIONS Here, we reveal miR-193a plays a suppressive role in osteogenic differentiation of hBMSC via targeting HMGB1. These findings provide a novel mechanism underlying osteogenic differentiation and offer therapeutical strategy for bone formation.
Collapse
|
23
|
|
24
|
|
25
|
Serum HMGB1 Serves as a Novel Laboratory Indicator Reflecting Disease Activity and Treatment Response in Ankylosing Spondylitis Patients. J Immunol Res 2016; 2016:6537248. [PMID: 27800496 PMCID: PMC5069358 DOI: 10.1155/2016/6537248] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Accepted: 07/10/2016] [Indexed: 01/10/2023] Open
Abstract
Objective. High mobility group box 1 (HMGB1) is a late inflammatory factor participating in the pathogenesis of various autoimmune and inflammatory diseases. In the current study, we analyzed the association between serum levels of HMGB1 and clinical features of AS patients before and during treatment. Methods. Serum HMGB1 was detected in 147 AS patients and 61 healthy controls using ELISA. We evaluated the association between HMGB1 and extra-articular manifestations as well as disease severity indices. Among these AS patients, 41 patients received close follow-up at 1, 3, and 6 months after treatment. This group comprised 25 patients treated with anti-TNF-α biologics and 16 patients receiving oral NSAIDs plus sulfasalazine. Results. The serum HMGB1 of AS patients was significantly higher than in healthy controls and positively correlated with BASDAI, BASFI, ASDAS-ESR, ASDAS-CRP, ESR, and CRP, but not with HLA-B27, anterior uveitis, and recurrent diarrhea. There was no significant difference between patients with radiographic damage of hip joints and those without. We observed that serum HMGB1 paralleled disease activity after treatment. Conclusion. Serum level of HMGB1 is higher in AS patients, and to some extent, HMGB1 can reflect the activity of AS and be used as a laboratory indicator to reflect the therapeutic response.
Collapse
|
26
|
Martinotti S, Patrone M, Manfredi M, Gosetti F, Pedrazzi M, Marengo E, Ranzato E. HMGB1 Osteo-Modulatory Action on Osteosarcoma SaOS-2 Cell Line: An Integrated Study From Biochemical and -Omics Approaches. J Cell Biochem 2016; 117:2559-69. [PMID: 27012556 DOI: 10.1002/jcb.25549] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 03/22/2016] [Indexed: 01/10/2023]
Abstract
High mobility group box protein-1 (HMGB1) is released from cells under various pathological conditions and it plays a pivotal role as an alarmin signaling tissue damage. Little is known about the impact of HMGB1 in bone repair and remodeling. To this aim, we focused on HMGB1-induced effects on the in vitro osteoblast model SaOS-2. Cell proliferation was stimulated with a maximum at concentration of 2.5 nM, and such a dose also stimulated cell migration and scratch wound healing. We then characterized the modulatory effect of HMGB1 on bone biology, by using osteogenesis/mineralization assays, a PCR array, and the analysis of a series of osteogenic markers. We performed also a proteomic screening using SWATH-MS on SaOS-2 cell exposed to HMGB1 and we provide evidence for proteins modulated in HMGB1 exposed cells. Taken together, our data demonstrate that SaOS-2 cell proliferation, migration, and osteogenic differentiation were increased by HMGB1. We, therefore, propose that HMGB1 could be a potent bone-remodeling signal but the physiological meaning of this property remains to be more ascertained. J. Cell. Biochem. 117: 2559-2569, 2016. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Simona Martinotti
- DiSIT-Dipartimento di Scienze e Innovazione Tecnologica, University of Piemonte Orientale, Viale Teresa Michel 11, Alessandria 15121, Italy.
| | - Mauro Patrone
- DiSIT-Dipartimento di Scienze e Innovazione Tecnologica, University of Piemonte Orientale, Viale Teresa Michel 11, Alessandria 15121, Italy
| | - Marcello Manfredi
- DiSIT-Dipartimento di Scienze e Innovazione Tecnologica, University of Piemonte Orientale, Viale Teresa Michel 11, Alessandria 15121, Italy.,Isalit srl, sede legale-via Bovio, 6, Novara; sede operativa-Politecnico di Torino, sede di Alessandria, viale Teresa Michel 5, Alessandria 15121, Italy
| | - Fabio Gosetti
- DiSIT-Dipartimento di Scienze e Innovazione Tecnologica, University of Piemonte Orientale, Viale Teresa Michel 11, Alessandria 15121, Italy
| | - Marco Pedrazzi
- Department of Experimental Medicine (DIMES)-Biochemistry Section, University of Genova, Viale Benedetto XV 1, Genova 16132, Italy
| | - Emilio Marengo
- DiSIT-Dipartimento di Scienze e Innovazione Tecnologica, University of Piemonte Orientale, Viale Teresa Michel 11, Alessandria 15121, Italy
| | - Elia Ranzato
- DiSIT-Dipartimento di Scienze e Innovazione Tecnologica, University of Piemonte Orientale, Viale Teresa Michel 11, Alessandria 15121, Italy
| |
Collapse
|
27
|
Cheung WY, Fritton JC, Morgan SA, Seref-Ferlengez Z, Basta-Pljakic J, Thi MM, Suadicani SO, Spray DC, Majeska RJ, Schaffler MB. Pannexin-1 and P2X7-Receptor Are Required for Apoptotic Osteocytes in Fatigued Bone to Trigger RANKL Production in Neighboring Bystander Osteocytes. J Bone Miner Res 2016; 31:890-9. [PMID: 26553756 PMCID: PMC4915221 DOI: 10.1002/jbmr.2740] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Revised: 11/05/2015] [Accepted: 11/08/2015] [Indexed: 12/13/2022]
Abstract
Osteocyte apoptosis is required to induce intracortical bone remodeling after microdamage in animal models, but how apoptotic osteocytes signal neighboring "bystander" cells to initiate the remodeling process is unknown. Apoptosis has been shown to open pannexin-1 (Panx1) channels to release adenosine diphosphate (ATP) as a "find-me" signal for phagocytic cells. To address whether apoptotic osteocytes use this signaling mechanism, we adapted the rat ulnar fatigue-loading model to reproducibly introduce microdamage into mouse cortical bone and measured subsequent changes in osteocyte apoptosis, receptor activator of NF-κB ligand (RANKL) expression and osteoclastic bone resorption in wild-type (WT; C57Bl/6) mice and in mice genetically deficient in Panx1 (Panx1KO). Mouse ulnar loading produced linear microcracks comparable in number and location to the rat model. WT mice showed increased osteocyte apoptosis and RANKL expression at microdamage sites at 3 days after loading and increased intracortical remodeling and endocortical tunneling at day 14. With fatigue, Panx1KO mice exhibited levels of microdamage and osteocyte apoptosis identical to WT mice. However, they did not upregulate RANKL in bystander osteocytes or initiate resorption. Panx1 interacts with P2X7 R in ATP release; thus, we examined P2X7 R-deficient mice and WT mice treated with P2X7 R antagonist Brilliant Blue G (BBG) to test the possible role of ATP as a find-me signal. P2X7 RKO mice failed to upregulate RANKL in osteocytes or induce resorption despite normally elevated osteocyte apoptosis after fatigue loading. Similarly, treatment of fatigued C57Bl/6 mice with BBG mimicked behavior of both Panx1KO and P2X7 RKO mice; BBG had no effect on osteocyte apoptosis in fatigued bone but completely prevented increases in bystander osteocyte RANKL expression and attenuated activation of resorption by more than 50%. These results indicate that activation of Panx1 and P2X7 R are required for apoptotic osteocytes in fatigued bone to trigger RANKL production in neighboring bystander osteocytes and implicate ATP as an essential signal mediating this process.
Collapse
Affiliation(s)
- Wing Yee Cheung
- Department of Biomedical Engineering, City College of New York, New York, NY, USA
| | - J Christopher Fritton
- Department of Orthopaedic Surgery, New Jersey Medical School, Rutgers University, Newark, NJ, USA
| | - Stacy Ann Morgan
- Department of Biomedical Engineering, City College of New York, New York, NY, USA
| | | | - Jelena Basta-Pljakic
- Department of Biomedical Engineering, City College of New York, New York, NY, USA
| | - Mia M Thi
- Departments of Orthopaedic Surgery, Urology, and Neuroscience, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY, USA
| | - Sylvia O Suadicani
- Departments of Orthopaedic Surgery, Urology, and Neuroscience, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY, USA
| | - David C Spray
- Departments of Orthopaedic Surgery, Urology, and Neuroscience, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY, USA
| | - Robert J Majeska
- Department of Biomedical Engineering, City College of New York, New York, NY, USA
| | - Mitchell B Schaffler
- Department of Biomedical Engineering, City College of New York, New York, NY, USA
| |
Collapse
|
28
|
Abstract
The decrease in bone mass and strength during aging has multiple causes. Osteocytes are long-lived cells within the bone matrix that perform a variety of functions, including the control of bone remodeling. Because of their longevity, osteocytes are more likely than osteoclasts or osteoblasts to accumulate molecular damage over time. Osteocytes utilize quality-control pathways like autophagy to remove damaged organelles and macromolecules, and thereby maintain function. When the damage is excessive, cell death pathways such as apoptosis minimize the impact of potential osteocyte dysfunction on the skeleton. The goal of this review is to discuss how dysregulation of these pathways in osteocytes may contribute to the decline in bone mass and strength with age.
Collapse
Affiliation(s)
- Robert L Jilka
- Center for Osteoporosis and Metabolic Bone Diseases, Central Arkansas Veterans Healthcare System, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA.
| | - Charles A O'Brien
- Center for Osteoporosis and Metabolic Bone Diseases, Central Arkansas Veterans Healthcare System, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA.
| |
Collapse
|
29
|
rhHMGB1 drives osteoblast migration in a TLR2/TLR4- and NF-κB-dependent manner. Biosci Rep 2016; 36:e00300. [PMID: 26744383 PMCID: PMC4759610 DOI: 10.1042/bsr20150239] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 01/06/2016] [Indexed: 02/02/2023] Open
Abstract
Osteoblast migration is significant in skeletal development. Recently, high mobility group box 1 protein (HMGB1) has been shown to highly expressed in cartilage to regulate endochondral ossification. Nevertheless, whether HMGB1 can modulate osteoblast proliferation and migration is poorly understood, as well as the intracellular signalling pathways that are involved in this process. Herein, we examined the effects of recombinant human HMGB1 (rhHMGB1) on the proliferation and migration of rat osteoblasts and investigated whether Toll-like receptor 2 (TLR2)- and TLR4-dependent signalling pathways are involved in the regulation of intracellular signalling. A transwell chamber assay was used to evaluate the migration of osteoblasts and the MTT assay was used to assess osteoblast proliferation. rhHMGB1 could significantly promote the migration of osteoblasts without inhibiting their proliferation. Meanwhile, rhHMGB1 can increase the nuclear translocation of nuclear factor-kappa B (NF-κB) p65. Specific siRNA constructs that target TLR2 or TLR4 could markedly inhibit HMGB1-induced migration of osteoblasts and HMGB1-enhanced activation of NF-κB. Collectively, HMGB1 could significantly enhance the migration of osteoblasts in vitro, and TLR2/TLR4-dependent NF-κB pathways are involved in HMGB1-induced osteoblast migration.
Collapse
|
30
|
Gallo J, Raska M, Konttinen YT, Nich C, Goodman SB. Innate immunity sensors participating in pathophysiology of joint diseases: a brief overview. J Long Term Eff Med Implants 2015; 24:297-317. [PMID: 25747032 DOI: 10.1615/jlongtermeffmedimplants.2014010825] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The innate immune system consists of functionally specialized "modules" that are activated in response to a particular set of stimuli via sensors located on the surface or inside the tissue cells. These cells screen tissues for a wide range of exogenous and endogenous danger/damage-induced signals with the aim to reject or tolerate them and maintain tissue integrity. In this line of thinking, inflammation evolved as an adaptive tool for restoring tissue homeostasis. A number of diseases are mediated by a maladaptation of the innate immune response, perpetuating chronic inflammation and tissue damage. Here, we review recent evidence on the cross talk between innate immune sensors and development of rheumatoid arthritis, osteoarthritis, and aseptic loosening of total joint replacements. In relation to the latter topic, there is a growing body of evidence that aseptic loosening and periprosthetic osteolysis results from long-term maladaptation of periprosthetic tissues to the presence of by-products continuously released from an artificial joint.
Collapse
Affiliation(s)
- Jiri Gallo
- Department of Orthopedics, University Hospital and Faculty of Medicine and Dentistry, Palacky University, Olomouc 775 20, Czech Republic
| | - Milan Raska
- Department of Immunology, Faculty of Medicine & Dentistry, Palacky University, Hnevotinska 3, 775 15 Olomouc, Czech Republic
| | - Yrjo T Konttinen
- Department of Clinical Medicine, University of Helsinki and ORTON Orthopaedic Hospital of the Invalid Foundation, Helsinki, Finland
| | - Christophe Nich
- Laboratoire de Biomecanique et Biomateriaux Osteo-Articulaires - UMR CNRS 7052, Faculte de Medecine - Universite Paris 7, Paris, France; Department of Orthopaedic Surgery, European Teaching Hospital, Assistance Publique - Hopitaux de Paris
| | - Stuart B Goodman
- Department of Orthopaedic Surgery Stanford University Medical Center Redwood City, CA
| |
Collapse
|
31
|
Feng Y, Fang W, Li C, Guo H, Li Y, Long X. The expression of high-mobility group box protein-1 in temporomandibular joint osteoarthritis with disc perforation. J Oral Pathol Med 2015; 45:148-52. [PMID: 26082301 DOI: 10.1111/jop.12336] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/19/2015] [Indexed: 12/11/2022]
Affiliation(s)
- Yaping Feng
- State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education (KLOBM); School and Hospital of Stomatology; Wuhan University; Wuhan China
| | - Wei Fang
- State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education (KLOBM); School and Hospital of Stomatology; Wuhan University; Wuhan China
- Department of Oral and Maxillofacial Surgery; School and Hospital of Stomatology; Wuhan University; Wuhan China
| | - Cheng Li
- State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education (KLOBM); School and Hospital of Stomatology; Wuhan University; Wuhan China
| | - Huilin Guo
- State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education (KLOBM); School and Hospital of Stomatology; Wuhan University; Wuhan China
| | - Yingjie Li
- State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education (KLOBM); School and Hospital of Stomatology; Wuhan University; Wuhan China
- Department of Oral and Maxillofacial Surgery; School and Hospital of Stomatology; Wuhan University; Wuhan China
| | - Xing Long
- State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education (KLOBM); School and Hospital of Stomatology; Wuhan University; Wuhan China
- Department of Oral and Maxillofacial Surgery; School and Hospital of Stomatology; Wuhan University; Wuhan China
| |
Collapse
|
32
|
Kosaka T, Fukui R, Matsui M, Kurosaka Y, Nishimura H, Tanabe M, Takakura Y, Iwai K, Waki T, Fujita T. RAGE, receptor of advanced glycation endoproducts, negatively regulates chondrocytes differentiation. PLoS One 2014; 9:e108819. [PMID: 25275461 PMCID: PMC4183532 DOI: 10.1371/journal.pone.0108819] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Accepted: 09/04/2014] [Indexed: 12/11/2022] Open
Abstract
RAGE, receptor for advanced glycation endoproducts (AGE), has been characterized as an activator of osteoclastgenesis. However, whether RAGE directly regulates chondrocyte proliferation and differentiation is unclear. Here, we show that RAGE has an inhibitory role in chondrocyte differentiation. RAGE expression was observed in chondrocytes from the prehypertrophic to hypertrophic regions. In cultured cells, overexpression of RAGE or dominant-negative-RAGE (DN-RAGE) demonstrated that RAGE inhibited cartilaginous matrix production, while DN-RAGE promoted production. Additionally, RAGE regulated Ihh and Col10a1 negatively but upregulated PTHrP receptor. Ihh promoter analysis and real-time PCR analysis suggested that downregulation of Cdxs was the key for RAGE-induced inhibition of chondrocyte differentiation. Overexpression of the NF-κB inhibitor I-κB-SR inhibited RAGE-induced NF-κB activation, but did not influence inhibition of cartilaginous matrix production by RAGE. The inhibitory action of RAGE was restored by the Rho family GTPases inhibitor Toxin B. Furthermore, inhibitory action on Ihh, Col10a1 and Cdxs was reproduced by constitutively active forms, L63RhoA, L61Rac, and L61Cdc42, but not by I-κB-SR. Cdx1 induced Ihh and Col10a1 expressions and directly interacted with Ihh promoter. Retinoic acid (RA) partially rescued the inhibitory action of RAGE. These data combined suggests that RAGE negatively regulates chondrocyte differentiation at the prehypertrophic stage by modulating NF-κB-independent and Rho family GTPases-dependent mechanisms.
Collapse
Affiliation(s)
- Tatsuya Kosaka
- Molecular Toxicology lab, Department of Pharmaceutical Sciences, Ritsumeikan University, Shiga, Japan
| | - Rino Fukui
- Molecular Toxicology lab, Department of Pharmaceutical Sciences, Ritsumeikan University, Shiga, Japan
| | - Mio Matsui
- Molecular Toxicology lab, Department of Pharmaceutical Sciences, Ritsumeikan University, Shiga, Japan
| | - Yuko Kurosaka
- Molecular Toxicology lab, Department of Pharmaceutical Sciences, Ritsumeikan University, Shiga, Japan
| | - Haruka Nishimura
- Molecular Toxicology lab, Department of Pharmaceutical Sciences, Ritsumeikan University, Shiga, Japan
| | - Motoki Tanabe
- Molecular Toxicology lab, Department of Pharmaceutical Sciences, Ritsumeikan University, Shiga, Japan
| | - Yuuki Takakura
- Molecular Toxicology lab, Department of Pharmaceutical Sciences, Ritsumeikan University, Shiga, Japan
| | - Keisuke Iwai
- Molecular Toxicology lab, Department of Pharmaceutical Sciences, Ritsumeikan University, Shiga, Japan
| | - Takuya Waki
- Molecular Toxicology lab, Department of Pharmaceutical Sciences, Ritsumeikan University, Shiga, Japan
| | - Takashi Fujita
- Molecular Toxicology lab, Department of Pharmaceutical Sciences, Ritsumeikan University, Shiga, Japan
- * E-mail:
| |
Collapse
|
33
|
Kennedy OD, Laudier DM, Majeska RJ, Sun HB, Schaffler MB. Osteocyte apoptosis is required for production of osteoclastogenic signals following bone fatigue in vivo. Bone 2014; 64:132-7. [PMID: 24709687 PMCID: PMC4070223 DOI: 10.1016/j.bone.2014.03.049] [Citation(s) in RCA: 104] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Revised: 03/07/2014] [Accepted: 03/27/2014] [Indexed: 02/05/2023]
Abstract
Osteocyte apoptosis is spatially, temporally and functionally linked to the removal and replacement of microdamage in the bone. Recently we showed that microdamage elicits distinct responses in two populations of osteocytes near the injury site. Osteocytes directly adjacent to microdamage undergo apoptosis, whereas there is a second group of osteocytes located adjacent to the apoptotic population that upregulate expression of osteoclastogenic signaling molecules. In this study we used the pan-caspase inhibitor QVD to test the hypothesis that osteocyte apoptosis is an obligatory step in the production of key osteoclastogenic signals by in situ osteocytes in fatigue-damaged bone. We found, based on real-time PCR and immunohistochemistry assays, that expression of the apoptosis marker caspase-3 as well osteoclastogenic proteins RANKL and VEGF were increased following fatigue, while expression of the RANKL antagonist OPG decreased. However, when apoptosis was inhibited using QVD, these changes in gene expression were completely blocked. This dependence on apoptosis for neighboring non-apoptotic cells to produce signals that promote tissue remodeling also occurs in response to focal ischemic injury in the brain and heart, indicating that osteoclastic bone remodeling follows a common paradigm for localized tissue repair.
Collapse
Affiliation(s)
- Oran D Kennedy
- Department of Biomedical Engineering, The City College of New York of the City University of New York, New York, NY, USA.
| | - Damien M Laudier
- Department of Biomedical Engineering, The City College of New York of the City University of New York, New York, NY, USA
| | - Robert J Majeska
- Department of Biomedical Engineering, The City College of New York of the City University of New York, New York, NY, USA.
| | - Hui B Sun
- Department Radiation Oncology, Albert Einstein College of Medicine, Bronx, NY, USA; Department of Radiation Oncology, Albert Einstein College of Medicine, Bronx, NY, USA.
| | - Mitchell B Schaffler
- Department of Biomedical Engineering, The City College of New York of the City University of New York, New York, NY, USA.
| |
Collapse
|
34
|
Absorption, distribution and mechanism of action of SYSADOAS. Pharmacol Ther 2014; 142:362-74. [DOI: 10.1016/j.pharmthera.2014.01.002] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Accepted: 01/08/2014] [Indexed: 02/07/2023]
|
35
|
Gan X, Huang S, Liu Y, Yan SS, Yu H. The potential role of damage-associated molecular patterns derived from mitochondria in osteocyte apoptosis and bone remodeling. Bone 2014; 62:67-8. [PMID: 24503211 DOI: 10.1016/j.bone.2014.01.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Accepted: 01/18/2014] [Indexed: 02/05/2023]
Affiliation(s)
- Xueqi Gan
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China; Department of Prosthodontics, West China College of Stomatology, Sichuan University, Chengdu 610041, China
| | - Shengbin Huang
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China; Department of Prosthodontics, West China College of Stomatology, Sichuan University, Chengdu 610041, China
| | - Yang Liu
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China; Department of Prosthodontics, West China College of Stomatology, Sichuan University, Chengdu 610041, China
| | - Shirley ShiDu Yan
- Department of Pharmacology and Toxicology, and Higuchi Bioscience Center, School of Pharmacy, University of Kansas, Lawrence, KS 66047, USA
| | - Haiyang Yu
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China; Department of Prosthodontics, West China College of Stomatology, Sichuan University, Chengdu 610041, China.
| |
Collapse
|
36
|
Schaffler MB, Cheung WY, Majeska R, Kennedy O. Osteocytes: master orchestrators of bone. Calcif Tissue Int 2014; 94:5-24. [PMID: 24042263 PMCID: PMC3947191 DOI: 10.1007/s00223-013-9790-y] [Citation(s) in RCA: 305] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Accepted: 08/22/2013] [Indexed: 12/12/2022]
Abstract
Osteocytes comprise the overwhelming majority of cells in bone and are its only true "permanent" resident cell population. In recent years, conceptual and technological advances on many fronts have helped to clarify the role osteocytes play in skeletal metabolism and the mechanisms they use to perform them. The osteocyte is now recognized as a major orchestrator of skeletal activity, capable of sensing and integrating mechanical and chemical signals from their environment to regulate both bone formation and resorption. Recent studies have established that the mechanisms osteocytes use to sense stimuli and regulate effector cells (e.g., osteoblasts and osteoclasts) are directly coupled to the environment they inhabit-entombed within the mineralized matrix of bone and connected to each other in multicellular networks. Communication within these networks is both direct (via cell-cell contacts at gap junctions) and indirect (via paracrine signaling by secreted signals). Moreover, the movement of paracrine signals is dependent on the movement of both solutes and fluid through the space immediately surrounding the osteocytes (i.e., the lacunar-canalicular system). Finally, recent studies have also shown that the regulatory capabilities of osteocytes extend beyond bone to include a role in the endocrine control of systemic phosphate metabolism. This review will discuss how a highly productive combination of experimental and theoretical approaches has managed to unearth these unique features of osteocytes and bring to light novel insights into the regulatory mechanisms operating in bone.
Collapse
Affiliation(s)
- Mitchell B. Schaffler
- University: City College of New York, Department: Biomedical Engineering, Phone: 212-650-5070, Fax: 212-650-6727
| | - Wing-Yee Cheung
- University: City College of New York, Department: Biomedical Engineering
| | - Robert Majeska
- University: City College of New York, Department: Biomedical Engineering
| | - Oran Kennedy
- University: New York University, Department: Orthopaedic Surgery
| |
Collapse
|
37
|
Tolosa MJ, Chuguransky SR, Sedlinsky C, Schurman L, McCarthy AD, Molinuevo MS, Cortizo AM. Insulin-deficient diabetes-induced bone microarchitecture alterations are associated with a decrease in the osteogenic potential of bone marrow progenitor cells: preventive effects of metformin. Diabetes Res Clin Pract 2013; 101:177-86. [PMID: 23806481 DOI: 10.1016/j.diabres.2013.05.016] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Revised: 05/21/2013] [Accepted: 05/30/2013] [Indexed: 12/15/2022]
Abstract
AIMS Diabetes mellitus is associated with metabolic bone disease and increased low-impact fractures. The insulin-sensitizer metformin possesses in vitro, in vivo and ex vivo osteogenic effects, although this has not been adequately studied in the context of diabetes. We evaluated the effect of insulin-deficient diabetes and/or metformin on bone microarchitecture, on osteogenic potential of bone marrow progenitor cells (BMPC) and possible mechanisms involved. METHODS Partially insulin-deficient diabetes was induced in rats by nicotinamide/streptozotocin-injection, with or without oral metformin treatment. Femoral metaphysis micro-architecture, ex vivo osteogenic potential of BMPC, and BMPC expression of Runx-2, PPARγ and receptor for advanced glycation endproducts (RAGE) were investigated. RESULTS Histomorphometric analysis of diabetic femoral metaphysis demonstrated a slight decrease in trabecular area and a significant reduction in osteocyte density, growth plate height and TRAP (tartrate-resistant acid phosphatase) activity in the primary spongiosa. BMPC obtained from diabetic animals showed a reduction in Runx-2/PPARγ ratio and in their osteogenic potential, and an increase in RAGE expression. Metformin treatment prevented the diabetes-induced alterations in bone micro-architecture and BMPC osteogenic potential. CONCLUSION Partially insulin-deficient diabetes induces deleterious effects on long-bone micro-architecture that are associated with a decrease in BMPC osteogenic potential, which could be mediated by a decrease in their Runx-2/PPARγ ratio and up-regulation of RAGE. These diabetes-induced alterations can be totally or partially prevented by oral administration of metformin.
Collapse
Affiliation(s)
- María José Tolosa
- Laboratorio de Investigación en Osteopatías y Metabolismo Mineral, Department of Biological Sciences, School of Exact Sciences, National University of La Plata, Argentina
| | | | | | | | | | | | | |
Collapse
|
38
|
Abstract
Apoptotic death of osteocytes was recognized over 15 years ago, but its significance for bone homeostasis has remained elusive. A new paradigm has emerged that invokes osteocyte apoptosis as a critical event in the recruitment of osteoclasts to a specific site in response to skeletal unloading, fatigue damage, estrogen deficiency and perhaps in other states where bone must be removed. This is accomplished by yet to be defined signals emanating from dying osteocytes, which stimulate neighboring viable osteocytes to produce osteoclastogenic cytokines. The osteocyte apoptosis caused by chronic glucocorticoid administration does not increase osteoclasts; however, it does negatively impact maintenance of bone hydration, vascularity, and strength.
Collapse
Affiliation(s)
- Robert L Jilka
- Division of Endocrinology & Metabolism, Center for Osteoporosis and Metabolic Bone Diseases, Central Arkansas Veterans Healthcare System, 4301 W. Markham, Slot 587, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | | | | |
Collapse
|
39
|
Abstract
We introduced the mechanosome hypothesis in 2003 as a heuristic model for investigating mechanotransduction in bone (Pavalko et al., J Cell Biochem, 2003, 88(1):104-112). This model suggested specific approaches for investigating how mechanical information is conveyed from the membrane of the sensor bone cell to the target genes and how this transmitted information from the membrane is converted into changes in transcription. The key concepts underlying the mechanosome hypothesis are that load-induced deformation of bone deforms the sensor cell membrane; embedded in the membrane are the focal adhesion and cadherin-catenin complexes, which in turn are physically connected to the chromatin via a solid-state scaffold. The physical stimulation of the membrane launches multiprotein complexes (mechanosomes) from the adhesion platforms while concomitantly tugging target genes into position for contact with the incoming mechanosomes, the carriers of the mechanical information to the nucleus. The mechanosome is comprised of an adhesion-associated protein and a nucleocytoplasmic shuttling transcription factor. Upon arrival at the target gene, mechanosomes alter DNA conformation and thus influence the interactions between trans-acting proteins along the gene, changing gene activity. Here, we update significant progress related to the mechanosome concept since publication of our original hypothesis. The launching of adhesion- and cytoskeletal-associated proteins into the nucleus toward target genes appears to be a common mechanism for regulating cell response to changes in its mechanical microenvironment.
Collapse
Affiliation(s)
- Joseph P Bidwell
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | | |
Collapse
|
40
|
|
41
|
Philip BK, Childress PJ, Robling AG, Heller A, Nawroth PP, Bierhaus A, Bidwell JP. RAGE supports parathyroid hormone-induced gains in femoral trabecular bone. Am J Physiol Endocrinol Metab 2010; 298:E714-25. [PMID: 20028966 PMCID: PMC2838526 DOI: 10.1152/ajpendo.00564.2009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2009] [Accepted: 12/17/2009] [Indexed: 11/22/2022]
Abstract
Parathyroid hormone (PTH) restores bone mass to the osteopenic skeleton, but significant questions remain as to the underlying mechanisms. The receptor for advanced glycation end products (RAGE) is a multiligand receptor of the immunoglobulin superfamily; however, recent studies indicate a role in bone physiology. We investigated the significance of RAGE to hormone-induced increases in bone by treating 10-wk-old female Rage-knockout (KO) and wild-type (WT) mice with human PTH-(1-34) at 30 microg.kg(-1).day(-1) or vehicle control, 7 days/wk, for 7 wk. PTH produced equivalent relative gains in bone mineral density (BMD) and bone mineral content (BMC) throughout the skeleton in both genotypes. PTH-mediated relative increases in cortical area of the midshaft femur were not compromised in the null mice. However, the hormone-induced gain in femoral cancellous bone was significantly attenuated in Rage-KO mice. The loss of RAGE impaired PTH-mediated increases in femoral cancellous bone volume, connectivity density, and trabecular number but did not impact increases in trabecular thickness or decreases in trabecular spacing. Disabling RAGE reduced femoral expression of bone formation genes, but their relative PTH-responsiveness was not impaired. Neutralizing RAGE did not attenuate vertebral cancellous bone response to hormone. Rage-null mice exhibited an attenuated accrual rate of bone mass, with the exception of the spine, and an enhanced accrual rate of fat mass. We conclude that RAGE is necessary for key aspects of the skeleton's response to anabolic PTH. Specifically, RAGE is required for hormone-mediated improvement of femoral trabecular architecture but not intrinsically necessary for increasing cortical thickness.
Collapse
Affiliation(s)
- Binu K Philip
- Dept. of Anatomy & Cell Biology, Indiana University School of Medicine, Indianapolis, 46202, USA
| | | | | | | | | | | | | |
Collapse
|
42
|
Childress P, Robling AG, Bidwell JP. Nmp4/CIZ: road block at the intersection of PTH and load. Bone 2010; 46:259-66. [PMID: 19766748 PMCID: PMC2818167 DOI: 10.1016/j.bone.2009.09.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2009] [Revised: 09/10/2009] [Accepted: 09/14/2009] [Indexed: 11/17/2022]
Abstract
Teriparatide (parathyroid hormone, [PTH]) is the only FDA-approved drug that replaces bone lost to osteoporosis. Enhancing PTH efficacy will improve cost-effectiveness and ameliorate contraindications. Combining this hormone with load-bearing exercise may enhance therapeutic potential consistent with a growing body of evidence that these agonists are synergistic and share common signaling pathways. Additionally, neutralizing molecules that naturally suppress the anabolic response to PTH may also improve the efficacy of treatment with this hormone. Nmp4/CIZ (nuclear matrix protein 4/cas interacting zinc finger)-null mice have enhanced responses to intermittent PTH with respect to increasing trabecular bone mass and are also immune to disuse-induced bone loss likely by the removal of Nmp4/CIZ suppressive action on osteoblast function. Nmp4/CIZ activity may be sensitive to changes in the mechanical environment of the bone cell brought about by hormone- or mechanical load-induced changes in cell shape and adhesion. Nmp4 was identified in a screen for PTH-responsive nuclear matrix architectural transcription factors (ATFs) that we proposed translate hormone-induced changes in cell shape and adhesion into changes in target gene DNA conformation. CIZ was independently identified as a nucleocytoplasmic shuttling transcription factor associating with the mechano-sensitive focal adhesion proteins p130Cas and zxyin. The p130Cas/zyxin/Nmp4/CIZ pathway resembles the beta-catenin/TCF/LEF1 mechanotransduction response limb and both share features with the HMGB1 (high mobility group box 1)/RAGE (receptor for advanced glycation end products) signaling axis. Here we describe Nmp4/CIZ within the context of the PTH-induced anabolic response and consider the place of this molecule in the hierarchy of the PTH-load response network.
Collapse
Affiliation(s)
- Paul Childress
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | | | | |
Collapse
|
43
|
Bakker AD, Silva VCD, Krishnan R, Bacabac RG, Blaauboer ME, Lin YC, Marcantonio RAC, Cirelli JA, Klein-Nulend J. Tumor necrosis factor alpha and interleukin-1beta modulate calcium and nitric oxide signaling in mechanically stimulated osteocytes. ACTA ACUST UNITED AC 2010; 60:3336-45. [PMID: 19877030 DOI: 10.1002/art.24920] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Inflammatory diseases often coincide with reduced bone mass. Mechanoresponsive osteocytes regulate bone mass by maintaining the balance between bone formation and resorption. Despite its biologic significance, the effect of inflammation on osteocyte mechanoresponsiveness is not understood. To fill this gap, we investigated whether the inflammatory cytokines tumor necrosis factor alpha (TNFalpha) and interleukin-1beta (IL-1beta) modulate the osteocyte response to mechanical loading. METHODS MLO-Y4 osteocytes were incubated with TNFalpha (0.5-30 ng/ml) or IL-1beta (0.1-10 ng/ml) for 30 minutes or 24 hours, or with calcium inhibitors for 30 minutes. Cells were subjected to mechanical loading by pulsatile fluid flow (mean +/- amplitude 0.7 +/- 0.3 Pa, 5 Hz), and the response was quantified by measuring nitric oxide (NO) production using Griess reagent and by measuring intracellular calcium concentration ([Ca(2+)](i)) using Fluo-4/AM. Focal adhesions and filamentous actin (F-actin) were visualized by immunostaining, and apoptosis was quantified by measuring caspase 3/7 activity. Cell-generated tractions were quantified using traction force microscopy, and cytoskeletal stiffness was quantified using optical magnetic twisting cytometry. RESULTS Pulsatile fluid flow increased [Ca(2+)](i) within seconds (in 13% of cells) and NO production within 5 minutes (4.7-fold). TNFalpha and IL-1beta inhibited these responses. Calcium inhibitors decreased pulsatile fluid flow-induced NO production. TNFalpha and IL-1beta affected cytoskeletal stiffness, likely because 24 hours of incubation with TNFalpha and IL-1beta decreased the amount of F-actin. Incubation with IL-1beta for 24 hours stimulated osteocyte apoptosis. CONCLUSION Our results suggest that TNFalpha and IL-1beta inhibit mechanical loading-induced NO production by osteocytes via abrogation of pulsatile fluid flow-stimulated [Ca(2+)](i), and that IL-1beta stimulates osteocyte apoptosis. Since both NO and osteocyte apoptosis affect osteoclasts, these findings provide a mechanism by which inflammatory cytokines might contribute to bone loss and consequently affect bone mass in rheumatoid arthritis.
Collapse
Affiliation(s)
- A D Bakker
- ACTA-Universiteit van Amsterdam and Vrije Universiteit, Research Institute MOVE, Amsterdam, The Netherlands
| | | | | | | | | | | | | | | | | |
Collapse
|
44
|
Wu W, Wan W, Li ADQ. The nuclear architectural protein HMGA1a triggers receptor-mediated endocytosis. J Cell Biochem 2009; 108:791-801. [PMID: 19739099 DOI: 10.1002/jcb.22281] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
High mobility group proteins A (HMGA), nuclear architectural factors, locate in the cell nuclei and mostly execute gene-regulation function. However, our results reveal that a HMGA member (HMGA1a) has a unique plasma membrane receptor; this receptor specifically binds to HMGA-decorated species, effectively mediates endocytosis, and internalizes extracellular HMGA-functionalized cargoes. Indeed, dyes or nanoparticles labeled with HMGA1a protein readily enter Hela cells. Using a stratagem chemical cross-linker, we covalently bonded the HMGA receptor to the HMGA1a-GFP fusion protein, thus capturing the plasma membrane receptor. Subsequent Western blots and SDS-PAGE gel revealed that the HMGA receptor is a 26-kDa protein. Confocal live-cell microscopic imaging was used to monitor the whole endocytic process, in which the internalized HMGA1a-decorated species are transported by motor proteins on microtubules and eventually arrive at the late endosomes/lysosomes. Cell viability assays also suggested that extracellular HMGA1a protein directly influences the survival ability of Hela cells in a dose-dependent manner, implying versatility of HMGA1a protein and its potent role to suppress cancer cell survivability and to regulate growth.
Collapse
Affiliation(s)
- Wuwei Wu
- Department of Chemistry and Center for Materials Research, Washington State University, Pullman, Washington 99164, USA
| | | | | |
Collapse
|