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Cho S, Lee KS, Lee K, Kim HS, Park S, Yu SE, Ha H, Baek S, Kim J, Kim H, Lee JY, Lee S, Sung HJ. Surface Crystal and Degradability of Shape Memory Scaffold Essentialize Osteochondral Regeneration. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024:e2401989. [PMID: 38855993 DOI: 10.1002/smll.202401989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 05/27/2024] [Indexed: 06/11/2024]
Abstract
The minimally invasive deployment of scaffolds is a key safety factor for the regeneration of cartilage and bone defects. Osteogenesis relies primarily on cell-matrix interactions, whereas chondrogenesis relies on cell-cell aggregation. Bone matrix expansion requires osteoconductive scaffold degradation. However, chondrogenic cell aggregation is promoted on the repellent scaffold surface, and minimal scaffold degradation supports the avascular nature of cartilage regeneration. Here, a material satisfying these requirements for osteochondral regeneration is developed by integrating osteoconductive hydroxyapatite (HAp) with a chondroconductive shape memory polymer (SMP). The shape memory function-derived fixity and recovery of the scaffold enabled minimally invasive deployment and expansion to fill irregular defects. The crystalline phases on the SMP surface inhibited cell aggregation by suppressing water penetration and subsequent protein adsorption. However, HAp conjugation SMP (H-SMP) enhanced surface roughness and consequent cell-matrix interactions by limiting cell aggregation using crystal peaks. After mouse subcutaneous implantation, hydrolytic H-SMP accelerated scaffold degradation compared to that by the minimal degradation observed for SMP alone for two months. H-SMP and SMP are found to promote osteogenesis and chondrogenesis, respectively, in vitro and in vivo, including the regeneration of rat osteochondral defects using the binary scaffold form, suggesting that this material is promising for osteochondral regeneration.
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Affiliation(s)
- Sungwoo Cho
- Department of Medical Engineering, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Kang Suk Lee
- Department of Medical Engineering, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
- TMD LAB Co. Ltd., 6th Floor, 31, Gwangnaru-ro 8-gil, Seongdong-gu, Seoul, 04799, South Korea
| | - Kyubae Lee
- Department of Biomedical Materials, Konyang University, 158, Gwanjeodong-ro, Seo-gu, Daejeon, 35365, South Korea
| | - Hye-Seon Kim
- Department of Anesthesiology, Perioperative, and Pain Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Suji Park
- Department of Medical Engineering, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Seung Eun Yu
- Department of Medical Engineering, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Hyunsu Ha
- Department of Medical Engineering, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Sewoom Baek
- Department of Medical Engineering, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
- Department of Brain Korea 21 FOUR Project for Medical Science, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Jueun Kim
- Department of Medical Engineering, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
- Department of Brain Korea 21 FOUR Project for Medical Science, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Hyunjae Kim
- Department of Medical Engineering, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Ji Youn Lee
- Department of Brain Korea 21 FOUR Project for Medical Science, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Sangmin Lee
- Department of Medical Engineering, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Hak-Joon Sung
- Department of Medical Engineering, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
- TMD LAB Co. Ltd., 6th Floor, 31, Gwangnaru-ro 8-gil, Seongdong-gu, Seoul, 04799, South Korea
- Department of Brain Korea 21 FOUR Project for Medical Science, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
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2
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Peng Y, Qu R, Yang Y, Fan T, Sun B, Khan AU, Wu S, Liu W, Zhu J, Chen J, Li X, Dai J, Ouyang J. Regulation of the integrin αVβ3- actin filaments axis in early osteogenic differentiation of human mesenchymal stem cells under cyclic tensile stress. Cell Commun Signal 2023; 21:308. [PMID: 37904190 PMCID: PMC10614380 DOI: 10.1186/s12964-022-01027-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Accepted: 12/24/2022] [Indexed: 11/01/2023] Open
Abstract
BACKGROUND Integrins are closely related to mechanical conduction and play a crucial role in the osteogenesis of human mesenchymal stem cells. Here we wondered whether tensile stress could influence cell differentiation through integrin αVβ3. METHODS We inhibited the function of integrin αVβ3 of human mesenchymal stem cells by treating with c(RGDyk). Using cytochalasin D and verteporfin to inhibit polymerization of microfilament and function of nuclear Yes-associated protein (YAP), respectively. For each application, mesenchymal stem cells were loaded by cyclic tensile stress of 10% at 0.5 Hz for 2 h daily. Mesenchymal stem cells were harvested on day 7 post-treatment. Western blotting and quantitative RT-PCR were used to detect the expression of alkaline phosphatase (ALP), RUNX2, β-actin, integrin αVβ3, talin-1, vinculin, FAK, and nuclear YAP. Immunofluorescence staining detected vinculin, actin filaments, and YAP nuclear localization. RESULTS Cyclic tensile stress could increase the expression of ALP and RUNX2. Inhibition of integrin αVβ3 activation led to rearrangement of actin filaments and downregulated the expression of ALP, RUNX2 and promoted YAP nuclear localization. When microfilament polymerization was inhibited, ALP, RUNX2, and nuclear YAP nuclear localization decreased. Inhibition of YAP nuclear localization could reduce the expression of ALP and RUNX2. CONCLUSIONS Cyclic tensile stress promotes early osteogenesis of human mesenchymal stem cells via the integrin αVβ3-actin filaments axis. YAP nuclear localization participates in this process of human mesenchymal stem cells. Video Abstract.
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Affiliation(s)
- Yan Peng
- Guangdong Provincial Key Laboratory of Medical Biomechanics and Guangdong Engineering Research Center for Translation of Medical 3D Printing Application and National Virtual and Reality Experimental Education Center for Medical Morphology and National Key Discipline of Human Anatomy, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Rongmei Qu
- Guangdong Provincial Key Laboratory of Medical Biomechanics and Guangdong Engineering Research Center for Translation of Medical 3D Printing Application and National Virtual and Reality Experimental Education Center for Medical Morphology and National Key Discipline of Human Anatomy, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Yuchao Yang
- Guangdong Provincial Key Laboratory of Medical Biomechanics and Guangdong Engineering Research Center for Translation of Medical 3D Printing Application and National Virtual and Reality Experimental Education Center for Medical Morphology and National Key Discipline of Human Anatomy, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Tingyu Fan
- Guangdong Provincial Key Laboratory of Medical Biomechanics and Guangdong Engineering Research Center for Translation of Medical 3D Printing Application and National Virtual and Reality Experimental Education Center for Medical Morphology and National Key Discipline of Human Anatomy, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Bing Sun
- Guangdong Provincial Key Laboratory of Medical Biomechanics and Guangdong Engineering Research Center for Translation of Medical 3D Printing Application and National Virtual and Reality Experimental Education Center for Medical Morphology and National Key Discipline of Human Anatomy, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Asmat Ullah Khan
- Guangdong Provincial Key Laboratory of Medical Biomechanics and Guangdong Engineering Research Center for Translation of Medical 3D Printing Application and National Virtual and Reality Experimental Education Center for Medical Morphology and National Key Discipline of Human Anatomy, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Shutong Wu
- Guangdong Provincial Key Laboratory of Medical Biomechanics and Guangdong Engineering Research Center for Translation of Medical 3D Printing Application and National Virtual and Reality Experimental Education Center for Medical Morphology and National Key Discipline of Human Anatomy, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Wenqing Liu
- Guangdong Provincial Key Laboratory of Medical Biomechanics and Guangdong Engineering Research Center for Translation of Medical 3D Printing Application and National Virtual and Reality Experimental Education Center for Medical Morphology and National Key Discipline of Human Anatomy, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Jinhui Zhu
- Guangdong Provincial Key Laboratory of Medical Biomechanics and Guangdong Engineering Research Center for Translation of Medical 3D Printing Application and National Virtual and Reality Experimental Education Center for Medical Morphology and National Key Discipline of Human Anatomy, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Junxin Chen
- Shenzhen Andy New Material Technology Co., LTD, Shenzhen, 518106, China
| | - Xiaoqing Li
- Shenzhen Andy New Material Technology Co., LTD, Shenzhen, 518106, China
| | - Jingxing Dai
- Guangdong Provincial Key Laboratory of Medical Biomechanics and Guangdong Engineering Research Center for Translation of Medical 3D Printing Application and National Virtual and Reality Experimental Education Center for Medical Morphology and National Key Discipline of Human Anatomy, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China.
| | - Jun Ouyang
- Guangdong Provincial Key Laboratory of Medical Biomechanics and Guangdong Engineering Research Center for Translation of Medical 3D Printing Application and National Virtual and Reality Experimental Education Center for Medical Morphology and National Key Discipline of Human Anatomy, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China.
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3
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Mauro D, Gandolfo S, Tirri E, Schett G, Maksymowych WP, Ciccia F. The bone marrow side of axial spondyloarthritis. Nat Rev Rheumatol 2023:10.1038/s41584-023-00986-6. [PMID: 37407716 DOI: 10.1038/s41584-023-00986-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/26/2023] [Indexed: 07/07/2023]
Abstract
Spondyloarthritis (SpA) is characterized by the infiltration of innate and adaptive immune cells into entheses and bone marrow. Molecular, cellular and imaging evidence demonstrates the presence of bone marrow inflammation, a hallmark of SpA. In the spine and the peripheral joints, bone marrow is critically involved in the pathogenesis of SpA. Evidence suggests that bone marrow inflammation is associated with enthesitis and that there are roles for mechano-inflammation and intestinal inflammation in bone marrow involvement in SpA. Specific cell types (including mesenchymal stem cells, innate lymphoid cells and γδ T cells) and mediators (Toll-like receptors and cytokines such as TNF, IL-17A, IL-22, IL-23, GM-CSF and TGFβ) are involved in these processes. Using this evidence to demonstrate a bone marrow rather than an entheseal origin for SpA could change our understanding of the disease pathogenesis and the relevant therapeutic approach.
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Affiliation(s)
- Daniele Mauro
- Department of Precision Medicine, University of Campania "Luigi Vanvitelli", Naples, Italy
| | - Saviana Gandolfo
- Unit of Rheumatology, San Giovanni Bosco Hospital, Naples, Italy
| | - Enrico Tirri
- Unit of Rheumatology, San Giovanni Bosco Hospital, Naples, Italy
| | - Georg Schett
- Department of Internal Medicine 3, Friedrich-Alexander University (FAU) Erlangen-Nuremberg and Universitätsklinikum Erlangen, Erlangen, Germany
- Deutsches Zentrum Immuntherapie (DZI), FAU Erlangen-Nuremberg and Universitätsklinikum Erlangen, Erlangen, Germany
| | | | - Francesco Ciccia
- Department of Precision Medicine, University of Campania "Luigi Vanvitelli", Naples, Italy.
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Skedros JG, Cronin JT, Dayton MR, Bloebaum RD, Bachus KN. Exploration of the synergistic role of cortical thickness asymmetry ("Trabecular Eccentricity" concept) in reducing fracture risk in the human femoral neck and a control bone (Artiodactyl Calcaneus). J Theor Biol 2023; 567:111495. [PMID: 37068584 DOI: 10.1016/j.jtbi.2023.111495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 03/24/2023] [Accepted: 04/10/2023] [Indexed: 04/19/2023]
Abstract
The mechanobiology of the human femoral neck is a focus of research for many reasons including studies that aim to curb age-related bone loss that contributes to a near-exponential rate of hip fractures. Many believe that the femoral neck is often loaded in rather simple bending, which causes net tension stress in the upper (superior) femoral neck and net compression stress in its inferior aspect ("T/C paradigm"). This T/C loading regime lacks in vivo proof. The "C/C paradigm" is a plausible alternative simplified load history that is characterized by a gradient of net compression across the entire femoral neck; action of the gluteus medius and external rotators of the hip are important in this context. It is unclear which paradigm is at play in natural loading due to lack of in vivo bone strain data and deficiencies in understanding mechanisms and manifestations of bone adaptation in tension vs. compression. For these reasons, studies of the femoral neck would benefit from being compared to a 'control bone' that has been proven, by strain data, to be habitually loaded in bending. The artiodactyl (sheep and deer) calcaneus model has been shown to be a very suitable control in this context. However, the application of this control in understanding the load history of the femoral neck has only been attempted in two prior studies, which did not examine the interplay between cortical and trabecular bone, or potential load-sharing influences of tendons and ligaments. Our first goal is to compare fracture risk factors of the femoral neck in both paradigms. Our second goal is to compare and contrast the deer calcaneus to the human femoral neck in terms of fracture risk factors in the T/C paradigm (the C/C paradigm is not applicable in the artiodactyl calcaneus due to its highly constrained loading). Our third goal explores interplay between dorsal/compression and plantar/tension regions of the deer calcaneus and the load-sharing roles of a nearby ligament and tendon, with insights for translation to the femoral neck. These goals were achieved by employing the analytical model of Fox and Keaveny (J. Theoretical Biology 2001, 2003) that estimates fracture risk factors of the femoral neck. This model focuses on biomechanical advantages of the asymmetric distribution of cortical bone in the direction of habitual loading. The cortical thickness asymmetry of the femoral neck (thin superior cortex, thick inferior cortex) reflects the superior-inferior placement of trabecular bone (i.e., "trabecular eccentricity," TE). TE helps the femoral neck adapt to typical stresses and strains through load-sharing between superior and inferior cortices. Our goals were evaluated in the context of TE. Results showed the C/C paradigm has lower risk factors for the superior cortex and for the overall femoral neck, which is clinically relevant. TE analyses of the deer calcaneus revealed important synergism in load-sharing between the plantar/tension cortex and adjacent ligament/tendon, which challenges conventional understanding of how this control bone achieves functional adaptation. Comparisons with the control bone also exposed important deficiencies in current understanding of human femoral neck loading and its potential histocompositional adaptations.
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Affiliation(s)
- John G Skedros
- University of Utah, Department of Orthopaedics, Salt Lake City, UT, USA; Research Service, Veterans Affairs Medical Center, Salt Lake City, UT, USA.
| | - John T Cronin
- University of Utah, Department of Orthopaedics, Salt Lake City, UT, USA
| | - Michael R Dayton
- University of Colorado, Department of Orthopedics, Aurora, CO, USA
| | - Roy D Bloebaum
- University of Utah, Department of Orthopaedics, Salt Lake City, UT, USA; Research Service, Veterans Affairs Medical Center, Salt Lake City, UT, USA
| | - Kent N Bachus
- University of Utah, Department of Orthopaedics, Salt Lake City, UT, USA; Research Service, Veterans Affairs Medical Center, Salt Lake City, UT, USA
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5
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Matthews M, Cook E, Naguib N, Wiesner U, Lewis K. Intravital imaging of osteocyte integrin dynamic with locally injectable fluorescent nanoparticles. Bone 2023:116830. [PMID: 37327917 DOI: 10.1016/j.bone.2023.116830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 06/05/2023] [Accepted: 06/13/2023] [Indexed: 06/18/2023]
Abstract
Osteocytes are the resident mechanosensory cells in bone. They are responsible for skeletal homeostasis and adaptation to mechanical cues. Integrin proteins play a prominent role in osteocyte mechanotransduction, but the details are not well stratified. Intravital imaging with multiphoton microscopy presents an opportunity to study molecular level mechanobiological events in vivo and presents an opportunity to study integrin dynamics in osteocytes. However, fluorescent imaging limitations with respect to excessive optical scattering and low signal to noise ratio caused by mineralized bone matrix make such investigations non-trivial. Here, we demonstrate that ultra-small and bright fluorescent core-shell silica nanoparticles (<7 nm diameter), known as Cornell Prime Dots (C'Dots), are well-suited for the in vivo bone microenvironment and can improve intravital imaging capabilities. We report validation studies for C'Dots as a novel, locally injectable in vivo osteocyte imaging tool for both non-specific cellular uptake and for targeting integrins. The pharmacokinetics of C'Dots reveal distinct sex differences in nanoparticle intracellular dynamics and clearance in osteocytes, which represents a novel topic of study in bone biology. Integrin-targeted C'Dots were used to study osteocyte integrin dynamics. To the best of our knowledge, we report here the first evidence of osteocyte integrin endocytosis and recycling in vivo. Our results provide novel insights in osteocyte biology and will open up new lines of investigation that were previously unavailable in vivo.
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Affiliation(s)
- Melia Matthews
- Department of Biomedical Engineering, Cornell University, 237 Tower Rd, Ithaca 14850, NY, USA
| | - Emily Cook
- Department of Biomedical Engineering, Cornell University, 237 Tower Rd, Ithaca 14850, NY, USA
| | - Nada Naguib
- Department of Biomedical Engineering, Cornell University, 237 Tower Rd, Ithaca 14850, NY, USA
| | - Uli Wiesner
- Department of Materials Science and Engineering, Cornell University, Bard Hall 210, Ithaca 14850, NY, USA
| | - Karl Lewis
- Department of Biomedical Engineering, Cornell University, 237 Tower Rd, Ithaca 14850, NY, USA.
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6
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Qin L, Chen Z, Yang D, He T, Xu Z, Zhang P, Chen D, Yi W, Xiao G. Osteocyte β3 integrin promotes bone mass accrual and force-induced bone formation in mice. J Orthop Translat 2023; 40:58-71. [PMID: 37457310 PMCID: PMC10338905 DOI: 10.1016/j.jot.2023.05.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Revised: 04/24/2023] [Accepted: 05/08/2023] [Indexed: 07/18/2023] Open
Abstract
Background Cell culture studies demonstrate the importance of β3 integrin in osteocyte mechanotransduction. However, the in vivo roles of osteocyte β3 integrin in the regulation of bone homeostasis and mechanotransduction are poorly defined. Materials and methods To study the in vivo role of osteocyte β3 integrin in bone, we utilized the 10-kb Dmp1 (dentin matrix acidic phosphoprotein 1)-Cre to delete β3 integrin expression in osteocyte in mice. Micro-computerized tomography (μCT), bone histomorphometry and in vitro cell culture experiments were performed to determine the effects of osteocyte β3 integrin loss on bone mass accrual and biomechanical properties. In addition, in vivo tibial loading model was applied to study the possible involvement of osteocyte β3 integrin in the mediation of bone mechanotransduction. Results Deletion of β3 integrin in osteocytes resulted in a low bone mass and impaired biomechanical properties in load-bearing long bones in adult mice. The loss of β3 integrin led to abnormal cell morphology with reduced number and length of dentritic processes in osteocytes. Furthermore, osteocyte β3 integrin loss did not impact the osteoclast formation, but significantly reduced the osteoblast-mediated bone formation rate and reduced the osteogenic differentiation of the bone marrow stromal cells in the bone microenvironment. In addition, mechanical loading failed to accelerate the anabolic bone formation in mutant mice. Conclusions Our studies demonstrate the essential roles of osteocyte β3 integrin in regulating bone mass and mechanotransduction.
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Affiliation(s)
- Lei Qin
- Department of Orthopedics, Huazhong University of Science and Technology Union Shenzhen Hospital, Shenzhen, 518000, China
| | - Zecai Chen
- Department of Orthopedics, Huazhong University of Science and Technology Union Shenzhen Hospital, Shenzhen, 518000, China
| | - Dazhi Yang
- Department of Orthopedics, Huazhong University of Science and Technology Union Shenzhen Hospital, Shenzhen, 518000, China
| | - Tailin He
- Department of Biochemistry, School of Medicine, Southern University of Science and Technology, Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, Shenzhen Key Laboratory of Cell Microenvironment, Shenzhen, 518055, China
| | - Zhen Xu
- Department of Orthopedics, Huazhong University of Science and Technology Union Shenzhen Hospital, Shenzhen, 518000, China
| | - Peijun Zhang
- Department of Biochemistry, School of Medicine, Southern University of Science and Technology, Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, Shenzhen Key Laboratory of Cell Microenvironment, Shenzhen, 518055, China
| | - Di Chen
- Research Center for Human Tissues and Organs Degeneration, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Weihong Yi
- Department of Orthopedics, Huazhong University of Science and Technology Union Shenzhen Hospital, Shenzhen, 518000, China
| | - Guozhi Xiao
- Department of Biochemistry, School of Medicine, Southern University of Science and Technology, Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, Shenzhen Key Laboratory of Cell Microenvironment, Shenzhen, 518055, China
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7
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Reyes Fernandez PC, Wright CS, Masterson AN, Yi X, Tellman TV, Bonteanu A, Rust K, Noonan ML, White KE, Lewis KJ, Sankar U, Hum JM, Bix G, Wu D, Robling AG, Sardar R, Farach-Carson MC, Thompson WR. Gabapentin Disrupts Binding of Perlecan to the α 2δ 1 Voltage Sensitive Calcium Channel Subunit and Impairs Skeletal Mechanosensation. Biomolecules 2022; 12:biom12121857. [PMID: 36551284 PMCID: PMC9776037 DOI: 10.3390/biom12121857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 12/04/2022] [Accepted: 12/08/2022] [Indexed: 12/14/2022] Open
Abstract
Our understanding of how osteocytes, the principal mechanosensors within bone, sense and perceive force remains unclear. Previous work identified "tethering elements" (TEs) spanning the pericellular space of osteocytes and transmitting mechanical information into biochemical signals. While we identified the heparan sulfate proteoglycan perlecan (PLN) as a component of these TEs, PLN must attach to the cell surface to induce biochemical responses. As voltage-sensitive calcium channels (VSCCs) are critical for bone mechanotransduction, we hypothesized that PLN binds the extracellular α2δ1 subunit of VSCCs to couple the bone matrix to the osteocyte membrane. Here, we showed co-localization of PLN and α2δ1 along osteocyte dendritic processes. Additionally, we quantified the molecular interactions between α2δ1 and PLN domains and demonstrated for the first time that α2δ1 strongly associates with PLN via its domain III. Furthermore, α2δ1 is the binding site for the commonly used pain drug, gabapentin (GBP), which is associated with adverse skeletal effects when used chronically. We found that GBP disrupts PLN::α2δ1 binding in vitro, and GBP treatment in vivo results in impaired bone mechanosensation. Our work identified a novel mechanosensory complex within osteocytes composed of PLN and α2δ1, necessary for bone force transmission and sensitive to the drug GBP.
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Affiliation(s)
- Perla C. Reyes Fernandez
- Department of Physical Therapy, School of Health and Human Sciences, Indiana University, Indianapolis, IN 46202, USA
| | - Christian S. Wright
- Department of Physical Therapy, School of Health and Human Sciences, Indiana University, Indianapolis, IN 46202, USA
| | - Adrianna N. Masterson
- Department of Chemistry and Chemical Biology, School of Science, Indiana University, Indianapolis, IN 46202, USA
| | - Xin Yi
- Department of Physical Therapy, School of Health and Human Sciences, Indiana University, Indianapolis, IN 46202, USA
| | - Tristen V. Tellman
- Department of Diagnostic and Biomedical Sciences, School of Dentistry, The University of Texas Health Science Center at Houston, Houston, TX 77054, USA
| | - Andrei Bonteanu
- Department of Diagnostic and Biomedical Sciences, School of Dentistry, The University of Texas Health Science Center at Houston, Houston, TX 77054, USA
- Department of Bioengineering, George R. Brown School of Engineering, Rice University, Houston, TX 77005, USA
| | - Katie Rust
- Department of Physical Therapy, School of Health and Human Sciences, Indiana University, Indianapolis, IN 46202, USA
| | - Megan L. Noonan
- Department of Medical and Molecular Genetics, School of Medicine, Indiana University, Indianapolis, IN 46202, USA
| | - Kenneth E. White
- Department of Medical and Molecular Genetics, School of Medicine, Indiana University, Indianapolis, IN 46202, USA
| | - Karl J. Lewis
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Uma Sankar
- Department of Anatomy, Cell Biology and Physiology, School of Medicine, Indiana University, Indianapolis, IN 46202, USA
| | - Julia M. Hum
- Division of Biomedical Science, College of Osteopathic Medicine, Marian University, Indianapolis, IN 46222, USA
| | - Gregory Bix
- Departments of Neurosurgery and Neurology, School of Medicine, Tulane University, New Orleans, LA 70112, USA
| | - Danielle Wu
- Department of Diagnostic and Biomedical Sciences, School of Dentistry, The University of Texas Health Science Center at Houston, Houston, TX 77054, USA
- Department of Bioengineering, George R. Brown School of Engineering, Rice University, Houston, TX 77005, USA
| | - Alexander G. Robling
- Department of Anatomy, Cell Biology and Physiology, School of Medicine, Indiana University, Indianapolis, IN 46202, USA
| | - Rajesh Sardar
- Department of Chemistry and Chemical Biology, School of Science, Indiana University, Indianapolis, IN 46202, USA
| | - Mary C. Farach-Carson
- Department of Diagnostic and Biomedical Sciences, School of Dentistry, The University of Texas Health Science Center at Houston, Houston, TX 77054, USA
- Department of Bioengineering, George R. Brown School of Engineering, Rice University, Houston, TX 77005, USA
| | - William R. Thompson
- Department of Physical Therapy, School of Health and Human Sciences, Indiana University, Indianapolis, IN 46202, USA
- Department of Anatomy, Cell Biology and Physiology, School of Medicine, Indiana University, Indianapolis, IN 46202, USA
- Division of Biomedical Science, College of Osteopathic Medicine, Marian University, Indianapolis, IN 46222, USA
- Correspondence:
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8
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Wang JS, Wein MN. Pathways Controlling Formation and Maintenance of the Osteocyte Dendrite Network. Curr Osteoporos Rep 2022; 20:493-504. [PMID: 36087214 PMCID: PMC9718876 DOI: 10.1007/s11914-022-00753-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/22/2022] [Indexed: 01/30/2023]
Abstract
PURPOSE OF REVIEW The purpose of this review is to discuss the molecular mechanisms involved in osteocyte dendrite formation, summarize the similarities between osteocytic and neuronal projections, and highlight the importance of osteocyte dendrite maintenance in human skeletal disease. RECENT FINDINGS It is suggested that there is a causal relationship between the loss of osteocyte dendrites and the increased osteocyte apoptosis during conditions including aging, microdamage, and skeletal disease. A few mechanisms are proposed to control dendrite formation and outgrowth, such as via the regulation of actin polymerization dynamics. This review addresses the impact of osteocyte dendrites in bone health and disease. Recent advances in multi-omics, in vivo and in vitro models, and microscopy-based imaging have provided novel approaches to reveal the underlying mechanisms that regulate dendrite development. Future therapeutic approaches are needed to target the process of osteocyte dendrite formation.
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Affiliation(s)
- Jialiang S Wang
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Marc N Wein
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
- Broad Institute of Harvard and MIT, Cambridge, MA, USA.
- Harvard Stem Cell Institute, Cambridge, MA, USA.
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9
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Garcia-Moreno M, Jordan PM, Günther K, Dau T, Fritzsch C, Vermes M, Schoppa A, Ignatius A, Wildemann B, Werz O, Löffler B, Tuchscherr L. Osteocytes Serve as a Reservoir for Intracellular Persisting Staphylococcus aureus Due to the Lack of Defense Mechanisms. Front Microbiol 2022; 13:937466. [PMID: 35935196 PMCID: PMC9355688 DOI: 10.3389/fmicb.2022.937466] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 06/20/2022] [Indexed: 11/24/2022] Open
Abstract
Chronic staphylococcal osteomyelitis can persist for long time periods causing bone destruction. The ability of Staphylococcus aureus to develop chronic infections is linked to its capacity to invade and replicate within osteoblasts and osteocytes and to switch to a dormant phenotype called small colony variants. Recently, osteocytes were described as a main reservoir for this pathogen in bone tissue. However, the mechanisms involved in the persistence of S. aureus within these cells are still unknown. Here, we investigated the interaction between S. aureus and osteoblasts or osteocytes during infection. While osteoblasts are able to induce a strong antimicrobial response and eliminate intracellular S. aureus, osteocytes trigger signals to recruit immune cells and enhance inflammation but fail an efficient antimicrobial activity to clear the bacterial infection. Moreover, we found that extracellular signals from osteocytes enhance intracellular bacterial clearance by osteoblasts. Even though both cell types express Toll-like receptor (TLR) 2, the main TLR responsible for S. aureus detection, only osteoblasts were able to increase TLR2 expression after infection. Additionally, proteomic analysis indicates that reduced intracellular bacterial killing activity in osteocytes is related to low antimicrobial peptide expression. Nevertheless, high levels of lipid mediators and cytokines were secreted by osteocytes, suggesting that they can contribute to inflammation. Taken together, our results demonstrate that osteocytes contribute to severe inflammation observed in osteomyelitis and represent the main niche for S. aureus persistence due to their poor capacity for intracellular antimicrobial response.
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Affiliation(s)
| | - Paul M. Jordan
- Department of Pharmaceutical/Medicinal Chemistry, Institute of Pharmacy, Friedrich Schiller University Jena, Jena, Germany
| | - Kerstin Günther
- Department of Pharmaceutical/Medicinal Chemistry, Institute of Pharmacy, Friedrich Schiller University Jena, Jena, Germany
| | - Therese Dau
- Leibniz Institute on Aging, Fritz Lipmann Institute, Jena, Germany
| | - Christian Fritzsch
- Institute of Medical Microbiology, Jena University Hospital, Jena, Germany
| | - Monika Vermes
- Institute of Medical Microbiology, Jena University Hospital, Jena, Germany
| | - Astrid Schoppa
- Institute of Orthopaedic Research and Biomechanics, University Medical Center Ulm, Ulm, Germany
| | - Anita Ignatius
- Institute of Orthopaedic Research and Biomechanics, University Medical Center Ulm, Ulm, Germany
| | - Britt Wildemann
- Experimental Trauma Surgery, Department of Trauma, Hand and Reconstructive Surgery, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany
| | - Oliver Werz
- Department of Pharmaceutical/Medicinal Chemistry, Institute of Pharmacy, Friedrich Schiller University Jena, Jena, Germany
| | - Bettina Löffler
- Institute of Medical Microbiology, Jena University Hospital, Jena, Germany
| | - Lorena Tuchscherr
- Institute of Medical Microbiology, Jena University Hospital, Jena, Germany
- *Correspondence: Lorena Tuchscherr,
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10
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Lewis KJ. Osteocyte calcium signaling - A potential translator of mechanical load to mechanobiology. Bone 2021; 153:116136. [PMID: 34339908 DOI: 10.1016/j.bone.2021.116136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 06/25/2021] [Accepted: 07/27/2021] [Indexed: 10/20/2022]
Abstract
Osteocytes are embedded dendritic bone cells; by virtue of their position in bone tissue, ability to coordinate bone building osteoblasts and resorbing osteoclasts, and sensitivity to tissue level mechanical loading, they serve as the resident bone mechanosensor. The mechanisms osteocytes use to change mechanical loading into biological signals that drive tissue level changes has been well studied over the last 30 years, however the ways loading parameters are encoded at the cellular level are still not fully understood. Calcium signaling is a first messenger signal exhibited by osteocytes in response to mechanical forces. A body of work interrogating the mechanisms of osteocyte calcium signaling exists and is presently expanding, presenting the opportunity to better understand the relationship between calcium signaling characteristics and tuned osteocyte responses to tissue level strain features (e.g. magnitude, duration, frequency). This review covers the history of osteocyte load induced calcium signaling and highlights potential cellular mechanisms used by osteocytes to turn details about loading parameters into biological events.
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Affiliation(s)
- Karl J Lewis
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, United States of America.
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11
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Lewis KJ, Cabahug-Zuckerman P, Boorman-Padgett JF, Basta-Pljakic J, Louie J, Stephen S, Spray DC, Thi MM, Seref-Ferlengez Z, Majeska RJ, Weinbaum S, Schaffler MB. Estrogen depletion on In vivo osteocyte calcium signaling responses to mechanical loading. Bone 2021; 152:116072. [PMID: 34171514 PMCID: PMC8316427 DOI: 10.1016/j.bone.2021.116072] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 06/15/2021] [Accepted: 06/20/2021] [Indexed: 11/27/2022]
Abstract
Microstructural adaptation of bone in response to mechanical stimuli is diminished with estrogen deprivation. Here we tested in vivo whether ovariectomy (OVX) alters the acute response of osteocytes, the principal mechanosensory cells of bone, to mechanical loading in mice. We also used super resolution microscopy (Structured Illumination microscopy or SIM) in conjunction with immunohistochemistry to assess changes in the number and organization of "osteocyte mechanosomes" - complexes of Panx1 channels, P2X7 receptors and CaV3 voltage-gated Ca2+ channels clustered around αvβ3 integrin foci on osteocyte processes. Third metatarsals bones of mice expressing an osteocyte-targeted genetically encoded Ca2+ indicator (DMP1-GCaMP3) were cyclically loaded in vivo to strains from 250 to 3000 με and osteocyte intracellular Ca2+ signaling responses were assessed in mid-diaphyses using multiphoton microscopy. The number of Ca2+ signaling osteocytes in control mice increase monotonically with applied strain magnitude for the physiological range of strains. The relationship between the number of Ca2+ signaling osteocytes and loading was unchanged at 2 days post-OVX. However, it was altered markedly at 28 days post-OVX. At loads up to 1000 με, there was a dramatic reduction in number of responding (i.e. Ca2+ signaling) osteocytes; however, at higher strains the numbers of Ca2+ signaling osteocytes were similar to control mice. OVX significantly altered the abundance, make-up and organization of osteocyte mechanosome complexes on dendritic processes. Numbers of αvβ3 foci also staining with either Panx 1, P2X7R or CaV3 declined by nearly half after OVX, pointing to a loss of osteocyte mechanosomes on the dendritic processes with estrogen depletion. At the same time, the areas of the remaining foci that stained for αvβ3 and channel proteins increased significantly, a redistribution of mechanosome components suggesting a potential compensatory response. These results demonstrate that the deleterious effects of estrogen depletion on skeletal mechanical adaptation appear at the level of mechanosensation; osteocytes lose the ability to sense small (physiological) mechanical stimuli. This decline may result at least partly from changes in the structure and organization of osteocyte mechanosomes, which contribute to the distinctive sensitivity of osteocytes (particularly their dendritic processes) to mechanical stimulation.
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Affiliation(s)
- Karl J Lewis
- Department of Biomedical Engineering, The City College of New York, New York, NY, United States of America
| | - Pamela Cabahug-Zuckerman
- Department of Biomedical Engineering, The City College of New York, New York, NY, United States of America
| | - James F Boorman-Padgett
- Department of Biomedical Engineering, The City College of New York, New York, NY, United States of America
| | - Jelena Basta-Pljakic
- Department of Biomedical Engineering, The City College of New York, New York, NY, United States of America
| | - Joyce Louie
- Department of Biomedical Engineering, The City College of New York, New York, NY, United States of America
| | - Samuel Stephen
- Department of Biomedical Engineering, The City College of New York, New York, NY, United States of America
| | - David C Spray
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, United States of America
| | - Mia M Thi
- Orthopaedic Surgery, Albert Einstein College of Medicine, Bronx, NY, United States of America; Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, United States of America
| | - Zeynep Seref-Ferlengez
- Orthopaedic Surgery, Albert Einstein College of Medicine, Bronx, NY, United States of America
| | - Robert J Majeska
- Department of Biomedical Engineering, The City College of New York, New York, NY, United States of America
| | - Sheldon Weinbaum
- Department of Biomedical Engineering, The City College of New York, New York, NY, United States of America
| | - Mitchell B Schaffler
- Department of Biomedical Engineering, The City College of New York, New York, NY, United States of America.
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12
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Peng Y, Qu R, Feng Y, Huang X, Yang Y, Fan T, Sun B, Khan AU, Wu S, Dai J, Ouyang J. Regulation of the integrin αVβ3- actin filaments axis in early osteogenesis of human fibroblasts under cyclic tensile stress. Stem Cell Res Ther 2021; 12:523. [PMID: 34620239 PMCID: PMC8496073 DOI: 10.1186/s13287-021-02597-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Accepted: 07/11/2021] [Indexed: 11/23/2022] Open
Abstract
Background Integrins play a prominent role in osteogenic differentiation by transmitting both mechanical and chemical signals. Integrin expression is closely associated with tensile stress, which has a positive effect on osteogenic differentiation. We investigated the relationship between integrin αVβ3 and tensile stress. Methods Human fibroblasts were treated with c (RGDyk) and lentivirus transduction to inhibit function of integrin αVβ3. Y-15, cytochalasin D and verteporfin were used to inhibit phosphorylation of FAK, polymerization of microfilament and function of nuclear YAP, respectively. Fibroblasts were exposed to a cyclic tensile stress of 10% at 0.5 Hz, once a day for 2 h each application. Fibroblasts were harvested on day 4 and 7 post-treatment. The expression of ALP, RUNX2, integrin αVβ3, β-actin, talin-1, FAK, vinculin, and nuclear YAP was detected by Western blot or qRT-PCR. The expression and distribution of integrin αVβ3, vinculin, microfilament and nuclear YAP. Results Cyclic tensile stress was found to promote expression of ALP and RUNX2. Inhibition of integrin αVβ3 activation downregulated the rearrangement of microfilament and the expression of ALP, RUNX2 and nuclear YAP. When the polymerization of microfilament was inhibited the expression of ALP, RUNX2 and nuclear YAP were decreased. The phosphorylation of FAK induced by cyclic tensile stress reduced by the inhibition of integrin αVβ3. The expression of ALP and RUNX2 was decreased by inhibition of phosphorylation of FAK and inhibition of nuclear YAP. Conclusions Cyclic tensile stress promotes osteogenesis of human fibroblasts via integrin αVβ3-microfilament axis. Phosphorylation of FAK and nuclear YAP participates in this process. Supplementary Information The online version contains supplementary material available at 10.1186/s13287-021-02597-y.
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Affiliation(s)
- Yan Peng
- Guangdong Provincial Key Laboratory of Medical Biomechanics and Department of Anatomy, School of Basic Medical Science, Southern Medical University, Guangzhou, 510000, China
| | - Rongmei Qu
- Guangdong Provincial Key Laboratory of Medical Biomechanics and Department of Anatomy, School of Basic Medical Science, Southern Medical University, Guangzhou, 510000, China
| | - Yanting Feng
- Department of Ophthalmology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510000, Guangdong, China
| | - Xiaolan Huang
- Guangdong Provincial Key Laboratory of Medical Biomechanics and Department of Anatomy, School of Basic Medical Science, Southern Medical University, Guangzhou, 510000, China
| | - Yuchao Yang
- Guangdong Provincial Key Laboratory of Medical Biomechanics and Department of Anatomy, School of Basic Medical Science, Southern Medical University, Guangzhou, 510000, China
| | - Tingyu Fan
- Guangdong Provincial Key Laboratory of Medical Biomechanics and Department of Anatomy, School of Basic Medical Science, Southern Medical University, Guangzhou, 510000, China
| | - Bing Sun
- Guangdong Provincial Key Laboratory of Medical Biomechanics and Department of Anatomy, School of Basic Medical Science, Southern Medical University, Guangzhou, 510000, China
| | - Asmat Ullah Khan
- Guangdong Provincial Key Laboratory of Medical Biomechanics and Department of Anatomy, School of Basic Medical Science, Southern Medical University, Guangzhou, 510000, China
| | - Shutong Wu
- Guangdong Provincial Key Laboratory of Medical Biomechanics and Department of Anatomy, School of Basic Medical Science, Southern Medical University, Guangzhou, 510000, China
| | - Jingxing Dai
- Guangdong Provincial Key Laboratory of Medical Biomechanics and Department of Anatomy, School of Basic Medical Science, Southern Medical University, Guangzhou, 510000, China.
| | - Jun Ouyang
- Guangdong Provincial Key Laboratory of Medical Biomechanics and Department of Anatomy, School of Basic Medical Science, Southern Medical University, Guangzhou, 510000, China.
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13
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Gould NR, Torre OM, Leser JM, Stains JP. The cytoskeleton and connected elements in bone cell mechano-transduction. Bone 2021; 149:115971. [PMID: 33892173 PMCID: PMC8217329 DOI: 10.1016/j.bone.2021.115971] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 03/30/2021] [Accepted: 04/17/2021] [Indexed: 02/07/2023]
Abstract
Bone is a mechano-responsive tissue that adapts to changes in its mechanical environment. Increases in strain lead to increased bone mass acquisition, whereas decreases in strain lead to a loss of bone mass. Given that mechanical stress is a regulator of bone mass and quality, it is important to understand how bone cells sense and transduce these mechanical cues into biological changes to identify druggable targets that can be exploited to restore bone cell mechano-sensitivity or to mimic mechanical load. Many studies have identified individual cytoskeletal components - microtubules, actin, and intermediate filaments - as mechano-sensors in bone. However, given the high interconnectedness and interaction between individual cytoskeletal components, and that they can assemble into multiple discreet cellular structures, it is likely that the cytoskeleton as a whole, rather than one specific component, is necessary for proper bone cell mechano-transduction. This review will examine the role of each cytoskeletal element in bone cell mechano-transduction and will present a unified view of how these elements interact and work together to create a mechano-sensor that is necessary to control bone formation following mechanical stress.
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Affiliation(s)
- Nicole R Gould
- Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Olivia M Torre
- Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Jenna M Leser
- Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Joseph P Stains
- Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, MD 21201, USA..
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14
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Sato T, Verma S, Andrade CDC, Omeara M, Campbell N, Wang JS, Cetinbas M, Lang A, Ausk BJ, Brooks DJ, Sadreyev RI, Kronenberg HM, Lagares D, Uda Y, Pajevic PD, Bouxsein ML, Gross TS, Wein MN. A FAK/HDAC5 signaling axis controls osteocyte mechanotransduction. Nat Commun 2020; 11:3282. [PMID: 32612176 PMCID: PMC7329900 DOI: 10.1038/s41467-020-17099-3] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 06/11/2020] [Indexed: 11/13/2022] Open
Abstract
Osteocytes, cells ensconced within mineralized bone matrix, are the primary skeletal mechanosensors. Osteocytes sense mechanical cues by changes in fluid flow shear stress (FFSS) across their dendritic projections. Loading-induced reductions of osteocytic Sclerostin (encoded by Sost) expression stimulates new bone formation. However, the molecular steps linking mechanotransduction and Sost suppression remain unknown. Here, we report that class IIa histone deacetylases (HDAC4 and HDAC5) are required for loading-induced Sost suppression and bone formation. FFSS signaling drives class IIa HDAC nuclear translocation through a signaling pathway involving direct HDAC5 tyrosine 642 phosphorylation by focal adhesion kinase (FAK), a HDAC5 post-translational modification that controls its subcellular localization. Osteocyte cell adhesion supports FAK tyrosine phosphorylation, and FFSS triggers FAK dephosphorylation. Pharmacologic FAK catalytic inhibition reduces Sost mRNA expression in vitro and in vivo. These studies demonstrate a role for HDAC5 as a transducer of matrix-derived cues to regulate cell type-specific gene expression.
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Affiliation(s)
- Tadatoshi Sato
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA USA
| | - Shiv Verma
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA USA
| | | | - Maureen Omeara
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA USA
| | - Nia Campbell
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA USA
| | - Jialiang S. Wang
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA USA
| | - Murat Cetinbas
- Department of Molecular Biology and Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, MA USA
| | - Audrey Lang
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA USA
| | - Brandon J. Ausk
- 0000000122986657grid.34477.33Department of Orthopaedics and Sports Medicine, University of Washington, Seattle, WA USA
| | - Daniel J. Brooks
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA USA ,Center for Advanced Orthopaedic Studies, Department of Orthopedic Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA USA
| | - Ruslan I. Sadreyev
- Department of Molecular Biology and Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, MA USA
| | - Henry M. Kronenberg
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA USA
| | - David Lagares
- Center for Immunology and Inflammatory Diseases, Fibrosis Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA USA
| | - Yuhei Uda
- 0000 0004 1936 7558grid.189504.1Translational Dental Medicine, Henry M. Goldman School of Dental Medicine, Boston University, Boston, MA USA
| | - Paola Divieti Pajevic
- 0000 0004 1936 7558grid.189504.1Translational Dental Medicine, Henry M. Goldman School of Dental Medicine, Boston University, Boston, MA USA
| | - Mary L. Bouxsein
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA USA ,Center for Advanced Orthopaedic Studies, Department of Orthopedic Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA USA
| | - Ted S. Gross
- 0000000122986657grid.34477.33Department of Orthopaedics and Sports Medicine, University of Washington, Seattle, WA USA
| | - Marc N. Wein
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA USA ,grid.66859.34Broad Institute of Harvard and MIT, Cambridge, MA USA
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15
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Qin L, Liu W, Cao H, Xiao G. Molecular mechanosensors in osteocytes. Bone Res 2020; 8:23. [PMID: 32550039 PMCID: PMC7280204 DOI: 10.1038/s41413-020-0099-y] [Citation(s) in RCA: 186] [Impact Index Per Article: 46.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 04/07/2020] [Accepted: 04/17/2020] [Indexed: 12/11/2022] Open
Abstract
Osteocytes, the most abundant and long-lived cells in bone, are the master regulators of bone remodeling. In addition to their functions in endocrine regulation and calcium and phosphate metabolism, osteocytes are the major responsive cells in force adaptation due to mechanical stimulation. Mechanically induced bone formation and adaptation, disuse-induced bone loss and skeletal fragility are mediated by osteocytes, which sense local mechanical cues and respond to these cues in both direct and indirect ways. The mechanotransduction process in osteocytes is a complex but exquisite regulatory process between cells and their environment, between neighboring cells, and between different functional mechanosensors in individual cells. Over the past two decades, great efforts have focused on finding various mechanosensors in osteocytes that transmit extracellular mechanical signals into osteocytes and regulate responsive gene expression. The osteocyte cytoskeleton, dendritic processes, Integrin-based focal adhesions, connexin-based intercellular junctions, primary cilium, ion channels, and extracellular matrix are the major mechanosensors in osteocytes reported so far with evidence from both in vitro and in vitro studies. This review aims to give a systematic introduction to osteocyte mechanobiology, provide details of osteocyte mechanosensors, and discuss the roles of osteocyte mechanosensitive signaling pathways in the regulation of bone homeostasis.
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Affiliation(s)
- Lei Qin
- Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, Shenzhen Key Laboratory of Cell Microenvironment, and School of Medicine, Southern University of Science and Technology, Shenzhen, 518055 China
| | - Wen Liu
- Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, Shenzhen Key Laboratory of Cell Microenvironment, and School of Medicine, Southern University of Science and Technology, Shenzhen, 518055 China
| | - Huiling Cao
- Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, Shenzhen Key Laboratory of Cell Microenvironment, and School of Medicine, Southern University of Science and Technology, Shenzhen, 518055 China
| | - Guozhi Xiao
- Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, Shenzhen Key Laboratory of Cell Microenvironment, and School of Medicine, Southern University of Science and Technology, Shenzhen, 518055 China
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16
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Takemura Y, Moriyama Y, Ayukawa Y, Kurata K, Rakhmatia YD, Koyano K. Mechanical loading induced osteocyte apoptosis and connexin 43 expression in three-dimensional cell culture and dental implant model. J Biomed Mater Res A 2019; 107:815-827. [DOI: 10.1002/jbm.a.36597] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Revised: 12/06/2018] [Accepted: 12/18/2018] [Indexed: 11/09/2022]
Affiliation(s)
- Yoko Takemura
- Section of Implant and Rehabilitative Dentistry, Division of Oral Rehabilitation, Faculty of Dental Science; Kyushu University; Fukuoka Japan
| | - Yasuko Moriyama
- Section of Implant and Rehabilitative Dentistry, Division of Oral Rehabilitation, Faculty of Dental Science; Kyushu University; Fukuoka Japan
| | - Yasunori Ayukawa
- Section of Implant and Rehabilitative Dentistry, Division of Oral Rehabilitation, Faculty of Dental Science; Kyushu University; Fukuoka Japan
| | - Kosaku Kurata
- Department of Mechanical Engineering, Faculty of Engineering; Kyushu University; Fukuoka Japan
| | - Yunia D. Rakhmatia
- Section of Implant and Rehabilitative Dentistry, Division of Oral Rehabilitation, Faculty of Dental Science; Kyushu University; Fukuoka Japan
| | - Kiyoshi Koyano
- Section of Implant and Rehabilitative Dentistry, Division of Oral Rehabilitation, Faculty of Dental Science; Kyushu University; Fukuoka Japan
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17
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Xie J, Zhou C, Zhang D, Cai L, Du W, Li X, Zhou X. Compliant Substratum Changes Osteocyte Functions: The Role of ITGB3/FAK/β-Catenin Signaling Matters. ACS APPLIED BIO MATERIALS 2018; 1:792-801. [PMID: 34996170 DOI: 10.1021/acsabm.8b00246] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Jing Xie
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610064, China
| | - Chenchen Zhou
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610064, China
| | - Demao Zhang
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610064, China
| | - Linyi Cai
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610064, China
| | - Wei Du
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610064, China
| | - Xiaobing Li
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610064, China
| | - Xuedong Zhou
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610064, China
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18
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Lyons JS, Joca HC, Law RA, Williams KM, Kerr JP, Shi G, Khairallah RJ, Martin SS, Konstantopoulos K, Ward CW, Stains JP. Microtubules tune mechanotransduction through NOX2 and TRPV4 to decrease sclerostin abundance in osteocytes. Sci Signal 2017; 10:10/506/eaan5748. [PMID: 29162742 DOI: 10.1126/scisignal.aan5748] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The adaptation of the skeleton to its mechanical environment is orchestrated by mechanosensitive osteocytes, largely by regulating the abundance of sclerostin, a secreted inhibitor of bone formation. We defined a microtubule-dependent mechanotransduction pathway that linked fluid shear stress to reactive oxygen species (ROS) and calcium (Ca2+) signals that led to a reduction in sclerostin abundance in cultured osteocytes. We demonstrated that microtubules stabilized by detyrosination, a reversible posttranslational modification of polymerized α-tubulin, determined the stiffness of the cytoskeleton, which set the mechanoresponsive range of cultured osteocytes to fluid shear stress. We showed that fluid shear stress through the microtubule network activated NADPH oxidase 2 (NOX2)-generated ROS that target the Ca2+ channel TRPV4 to elicit Ca2+ influx. Furthermore, tuning the abundance of detyrosinated tubulin affected cytoskeletal stiffness to define the mechanoresponsive range of cultured osteocytes to fluid shear stress. Finally, we demonstrated that NOX2-ROS elicited Ca2+ signals that activated the kinase CaMKII to decrease the abundance of sclerostin protein. Together, these discoveries may identify potentially druggable targets for regulating osteocyte mechanotransduction to affect bone quality.
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Affiliation(s)
- James S Lyons
- Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Humberto C Joca
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Robert A Law
- Department of Chemical & Biomolecular Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Katrina M Williams
- Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Jaclyn P Kerr
- Department of Orthopaedics, University of Maryland School of Nursing, Baltimore, MD 21201, USA
| | - Guoli Shi
- Department of Orthopaedics, University of Maryland School of Nursing, Baltimore, MD 21201, USA
| | | | - Stuart S Martin
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | | | - Christopher W Ward
- Department of Orthopaedics, University of Maryland School of Nursing, Baltimore, MD 21201, USA.
| | - Joseph P Stains
- Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
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19
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Mensah SA, Cheng MJ, Homayoni H, Plouffe BD, Coury AJ, Ebong EE. Regeneration of glycocalyx by heparan sulfate and sphingosine 1-phosphate restores inter-endothelial communication. PLoS One 2017; 12:e0186116. [PMID: 29023478 PMCID: PMC5638341 DOI: 10.1371/journal.pone.0186116] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Accepted: 09/25/2017] [Indexed: 11/18/2022] Open
Abstract
Vasculoprotective endothelium glycocalyx (GCX) shedding plays a critical role in vascular disease. Previous work demonstrated that GCX degradation disrupts endothelial cell (EC) gap junction connexin (Cx) proteins, likely blocking interendothelial molecular transport that maintains EC and vascular tissue homeostasis to resist disease. Here, we focused on GCX regeneration and tested the hypothesis that vasculoprotective EC function can be stimulated via replacement of GCX when it is shed. We used EC with [i] intact heparan sulfate (HS), the most abundant GCX component; [ii] degraded HS; or [iii] HS that was restored after enzyme degradation, by cellular self-recovery or artificially. Artificial HS restoration was achieved via treatment with exogenous HS, with or without the GCX regenerator and protector sphingosine 1- phosphate (S1P). In these cells we immunocytochemically examined expression of Cx isotype 43 (Cx43) at EC borders and characterized Cx-containing gap junction activity by measuring interendothelial spread of gap junction permeable Lucifer Yellow dye. With intact HS, 60% of EC borders expressed Cx43 and dye spread to 2.88 ± 0.09 neighboring cells. HS degradation decreased Cx43 expression to 30% and reduced dye spread to 1.87± 0.06 cells. Cellular self-recovery of HS restored baseline levels of Cx43 and dye transfer. Artificial HS recovery with exogenous HS partially restored Cx43 expression to 46% and yielded dye spread to only 1.03 ± 0.07 cells. Treatment with both HS and S1P, recovered HS and restored Cx43 to 56% with significant dye transfer to 3.96 ± 0.23 cells. This is the first evidence of GCX regeneration in a manner that effectively restores vasculoprotective EC communication.
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Affiliation(s)
- Solomon A. Mensah
- Department of Bioengineering, Northeastern University, Boston, Massachusetts, United States of America
| | - Ming J. Cheng
- Department of Chemical Engineering, Northeastern University, Boston, Massachusetts, United States of America
| | - Homa Homayoni
- Department of Chemical Engineering, Northeastern University, Boston, Massachusetts, United States of America
| | - Brian D. Plouffe
- Department of Chemical Engineering, Northeastern University, Boston, Massachusetts, United States of America
| | - Arthur J. Coury
- Department of Chemical Engineering, Northeastern University, Boston, Massachusetts, United States of America
| | - Eno E. Ebong
- Department of Bioengineering, Northeastern University, Boston, Massachusetts, United States of America
- Department of Chemical Engineering, Northeastern University, Boston, Massachusetts, United States of America
- Department of Neuroscience, Albert Einstein College of Medicine, New York, New York, United States of America
- * E-mail:
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20
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Cell culture: complications due to mechanical release of ATP and activation of purinoceptors. Cell Tissue Res 2017; 370:1-11. [PMID: 28434079 PMCID: PMC5610203 DOI: 10.1007/s00441-017-2618-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 03/21/2017] [Indexed: 12/11/2022]
Abstract
There is abundant evidence that ATP (adenosine 5′-triphosphate) is released from a variety of cultured cells in response to mechanical stimulation. The release mechanism involved appears to be a combination of vesicular exocytosis and connexin and pannexin hemichannels. Purinergic receptors on cultured cells mediate both short-term purinergic signalling of secretion and long-term (trophic) signalling such as proliferation, migration, differentiation and apoptosis. We aim in this review to bring to the attention of non-purinergic researchers using tissue culture that the release of ATP in response to mechanical stress evoked by the unavoidable movement of the cells acting on functional purinergic receptors on the culture cells is likely to complicate the interpretation of their data.
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21
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Wu XT, Sun LW, Yang X, Ding D, Han D, Fan YB. The potential role of spectrin network in the mechanotransduction of MLO-Y4 osteocytes. Sci Rep 2017; 7:40940. [PMID: 28112189 PMCID: PMC5256107 DOI: 10.1038/srep40940] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 12/13/2016] [Indexed: 02/06/2023] Open
Abstract
The spectrin is first identified as the main component of erythrocyte membrane skeleton. It is getting growing attention since being found in multiple nonerythroid cells, providing complex mechanical properties and signal interface under the cell membrane. Recent genomics studies have revealed that the spectrin is highly relevant to bone disorders. However, in osteocytes, the important mechanosensors in bone, the role of spectrin is poorly understood. In this research, the role of spectrin in the mechanotransduction of MLO-Y4 osteocytes was studied. Immunofluorescence staining showed that, the spectrins were elaborately organized as a porous network throughout the cytoplasm, and linked with F-actin into a dense layer underlying the cell membrane. AFM results indicate that, the spectrin is pivotal for maintaining the overall elasticity of osteocytes, especially for the cell cortex stiffiness. Disruption of the spectrin network caused obvious softening of osteocytes, and resulted in a significant increase of Ca2+ influx, NO secretion, cell-cell connections and also induced a translocation of eNOS from membrane to cytoplasm. These results indicate that the spectrin network is a global structural support for osteocytes involving in the mechanotransduction process, making it a potential therapeutic target for bone disorders.
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Affiliation(s)
- Xin-Tong Wu
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, 37th Xue-yuan Road, Hian-dian District, Beijing, China
| | - Lian-Wen Sun
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, 37th Xue-yuan Road, Hian-dian District, Beijing, China.,International Joint Research Center of Aerospace Biotechnology and Medical Engineering, Ministry of Science and Technology of China, School of Biological Science and Medical Engineering, Beihang University, 37th Xue-yuan Road, Hian-dian District, Beijing, China
| | - Xiao Yang
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, 37th Xue-yuan Road, Hian-dian District, Beijing, China
| | - Dong Ding
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, 37th Xue-yuan Road, Hian-dian District, Beijing, China
| | - Dong Han
- National Center for Nanoscience and Technology, Beijing, China
| | - Yu-Bo Fan
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, 37th Xue-yuan Road, Hian-dian District, Beijing, China.,National Research Center for Rehabilitation Technical Aids, 1th Ronghuazhong Road, Beijing Economic and Technological Development Zone, China
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22
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Seref-Ferlengez Z, Suadicani SO, Thi MM. A new perspective on mechanisms governing skeletal complications in type 1 diabetes. Ann N Y Acad Sci 2016; 1383:67-79. [PMID: 27571221 DOI: 10.1111/nyas.13202] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Revised: 07/11/2016] [Accepted: 07/18/2016] [Indexed: 12/29/2022]
Abstract
This review focuses on bone mechanobiology in type 1 diabetes (T1D), an area of research on diabetes-associated skeletal complications that is still in its infancy. We first provide a brief overview of the deleterious effects of diabetes on the skeleton and of the knowledge gained from studies with rodent models of T1D. Second, we discuss two specific hallmarks of T1D, low insulin and high glucose, and address the extent to which they affect skeletal health. Third, we highlight the mechanosensitive nature of bone tissue and the importance of mechanical loading for bone health. We also summarize recent advances in bone mechanobiology that implicate osteocytes as the mechanosensors and major regulatory cells in the bone. Finally, we discuss recent evidence indicating that the diabetic bone is "deaf" to mechanical loading and that osteocytes are central players in mechanisms that lead to bone loss in T1D.
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Affiliation(s)
- Zeynep Seref-Ferlengez
- Department of Orthopaedic Surgery.,Laboratories of Musculoskeletal Orthopedic Research at Einstein-Montefiore (MORE)
| | - Sylvia O Suadicani
- Laboratories of Musculoskeletal Orthopedic Research at Einstein-Montefiore (MORE).,Department of Neuroscience.,Department of Urology, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, New York
| | - Mia M Thi
- Department of Orthopaedic Surgery.,Laboratories of Musculoskeletal Orthopedic Research at Einstein-Montefiore (MORE).,Department of Neuroscience
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23
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Fritz A, Bertin A, Hanna P, Nualart F, Marcellini S. A Single Chance to Contact Multiple Targets: Distinct Osteocyte Morphotypes Shed Light on the Cellular Mechanism Ensuring the Robust Formation of Osteocytic Networks. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2016; 326:280-9. [PMID: 27381191 DOI: 10.1002/jez.b.22683] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Revised: 06/03/2016] [Accepted: 06/10/2016] [Indexed: 01/16/2023]
Abstract
The formation of the complex osteocytic network relies on the emission of long cellular processes involved in communication, mechanical strain sensing, and bone turnover control. Newly deposited osteocytic processes rapidly become trapped within the calcifying matrix, and, therefore, they must adopt their definitive conformation and contact their targets in a single morphogenetic event. However, the cellular mechanisms ensuring the robustness of this unique mode of morphogenesis remain unknown. To address this issue, we examined the developing calvaria of the amphibian Xenopus tropicalis by confocal, two-photon, and super-resolution imaging, and described flattened osteocytes lying within a woven bone structured in lamellae of randomly oriented collagen fibers. While most cells emit peripheral and perpendicular processes, we report two osteocytes morphotypes, located at different depth within the bone matrix and exhibiting distinct number and orientation of perpendicular cell processes. We show that this pattern is conserved with the chick Gallus gallus and suggest that the cellular microenvironment, and more particularly cell-cell contact, plays a fundamental role in the induction and stabilization of osteocytic processes. We propose that this intrinsic property might have been evolutionarily selected for its ability to robustly generate self-organizing osteocytic networks harbored by the wide variety of bone shapes and architectures found in extant and extinct vertebrates.
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Affiliation(s)
- Alan Fritz
- Laboratory of Development and Evolution, Department of Cell Biology, Faculty of Biological Sciences, University of Concepcion, Concepción, Chile
| | - Ariana Bertin
- Laboratory of Development and Evolution, Department of Cell Biology, Faculty of Biological Sciences, University of Concepcion, Concepción, Chile
| | - Patricia Hanna
- Laboratory of Development and Evolution, Department of Cell Biology, Faculty of Biological Sciences, University of Concepcion, Concepción, Chile
| | - Francisco Nualart
- Center for Advanced Microscopy (CMA Bio-Bio), University of Concepcion, Concepción, Chile
| | - Sylvain Marcellini
- Laboratory of Development and Evolution, Department of Cell Biology, Faculty of Biological Sciences, University of Concepcion, Concepción, Chile
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24
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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.
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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
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25
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Kringelbach TM, Aslan D, Novak I, Ellegaard M, Syberg S, Andersen CKB, Kristiansen KA, Vang O, Schwarz P, Jørgensen NR. Fine-tuned ATP signals are acute mediators in osteocyte mechanotransduction. Cell Signal 2015; 27:2401-9. [PMID: 26327582 DOI: 10.1016/j.cellsig.2015.08.016] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 08/24/2015] [Accepted: 08/26/2015] [Indexed: 12/12/2022]
Abstract
Osteocytes are considered the primary mechanosensors of bone, but the signaling pathways they apply in mechanotransduction are still incompletely investigated and characterized. A growing body of data strongly indicates that P2 receptor signaling among osteoblasts and osteoclasts has regulatory effects on bone remodeling. Therefore, we hypothesized that ATP signaling is also applied by osteocytes in mechanotransduction. We applied a short fluid pulse on MLO-Y4 osteocyte-like cells during real-time detection of ATP and demonstrated that mechanical stimulation activates the acute release of ATP and that these acute ATP signals are fine-tuned according to the magnitude of loading. ATP release was then challenged by pharmacological inhibitors, which indicated a vesicular release pathway for acute ATP signals. Finally, we showed that osteocytes express functional P2X2 and P2X7 receptors and respond to even low concentrations of nucleotides by increasing intracellular calcium concentration. These results indicate that in osteocytes, vesicular ATP release is an acute mediator of mechanical signals and the magnitude of loading. These and previous results, therefore, implicate purinergic signaling as an early signaling pathway in osteocyte mechanotransduction.
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Affiliation(s)
- Tina M Kringelbach
- Research Center for Ageing and Osteoporosis, Department of Diagnostics, Copenhagen University Hospital Glostrup, Glostrup, Denmark; Research Center for Ageing and Osteoporosis, Department of Medicine, Copenhagen University Hospital Glostrup, Glostrup, Denmark; The Osteoporosis and Bone Metabolic Unit, Dept. of Endocrinology, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark; The Osteoporosis and Bone Metabolic Unit, Dept. of Clinical Biochemistry, Copenhagen, University Hospital Hvidovre, Hvidovre, Denmark
| | - Derya Aslan
- Research Center for Ageing and Osteoporosis, Department of Diagnostics, Copenhagen University Hospital Glostrup, Glostrup, Denmark; Research Center for Ageing and Osteoporosis, Department of Medicine, Copenhagen University Hospital Glostrup, Glostrup, Denmark
| | - Ivana Novak
- Department of Biology, University of Copenhagen, Copenhagen Ø, Denmark
| | - Maria Ellegaard
- Research Center for Ageing and Osteoporosis, Department of Diagnostics, Copenhagen University Hospital Glostrup, Glostrup, Denmark; Research Center for Ageing and Osteoporosis, Department of Medicine, Copenhagen University Hospital Glostrup, Glostrup, Denmark
| | - Susanne Syberg
- Research Center for Ageing and Osteoporosis, Department of Diagnostics, Copenhagen University Hospital Glostrup, Glostrup, Denmark; Research Center for Ageing and Osteoporosis, Department of Medicine, Copenhagen University Hospital Glostrup, Glostrup, Denmark
| | - Christina K B Andersen
- Research Center for Ageing and Osteoporosis, Department of Diagnostics, Copenhagen University Hospital Glostrup, Glostrup, Denmark; Research Center for Ageing and Osteoporosis, Department of Medicine, Copenhagen University Hospital Glostrup, Glostrup, Denmark
| | - Kim A Kristiansen
- Department of Clinical Research, Copenhagen University Hospital Glostrup, Glostrup, Denmark
| | - Ole Vang
- Department of Science, Systems and Models, Roskilde University, Roskilde, Denmark
| | - Peter Schwarz
- Research Center for Ageing and Osteoporosis, Department of Diagnostics, Copenhagen University Hospital Glostrup, Glostrup, Denmark; Research Center for Ageing and Osteoporosis, Department of Medicine, Copenhagen University Hospital Glostrup, Glostrup, Denmark; Faculty of Health Science, University of Copenhagen, Copenhagen, Denmark
| | - Niklas R Jørgensen
- Research Center for Ageing and Osteoporosis, Department of Diagnostics, Copenhagen University Hospital Glostrup, Glostrup, Denmark; Research Center for Ageing and Osteoporosis, Department of Medicine, Copenhagen University Hospital Glostrup, Glostrup, Denmark; The Osteoporosis and Bone Metabolic Unit, Dept. of Endocrinology, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark; The Osteoporosis and Bone Metabolic Unit, Dept. of Clinical Biochemistry, Copenhagen, University Hospital Hvidovre, Hvidovre, Denmark.
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26
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Mirbod P, Meng D. Analysis of bolus formation in micropipette ejection systems. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2015; 38:59. [PMID: 26100535 DOI: 10.1140/epje/i2015-15059-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Revised: 02/02/2015] [Accepted: 05/06/2015] [Indexed: 06/04/2023]
Abstract
The ejection of drugs from micropipettes is practiced frequently in biomedical research and clinical studies however, little is known about the dynamics of this process. The fundamentals of disperse fluid injection via a capillary into an ambient immiscible fluid have been investigated extensively. Here, we experimentally investigate the bolus formation in micropipette ejection systems, where the injection and ambient fluid are the same. We experimentally measure the temporal evolution of the bolus formation in the same fluid. There are three different bolus formation mechanisms that arise from different Re t regimes: a) a nearly spherical bolus, b) a pear-like bolus, and c) a large distortion or axial jet. We examine the scaled dimensions of the bolus, R b/D t, L b/D t, H/D t, and α, as a function of the dimensionless parameters such as tip Reynolds number, Re t, dimensionless value of g/(D t (.) V t), the dimensionless time, tV t/D t, and the distance between the edge of the micropipette and the free surface, D/D t. The bolus radius for 0.2 < Re t < 30 grows according to t (1/2) in the entire time range, which allows us to estimate the time for complete bolus formation.
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Affiliation(s)
- Parisa Mirbod
- Department of Mechanical and Aeronautical Engineering, Clarkson University, Potsdam, New York, USA.
| | - Diwen Meng
- Department of Mechanical and Aeronautical Engineering, Clarkson University, Potsdam, New York, USA
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27
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Marie PJ, Haÿ E, Saidak Z. Integrin and cadherin signaling in bone: role and potential therapeutic targets. Trends Endocrinol Metab 2014; 25:567-75. [PMID: 25034128 DOI: 10.1016/j.tem.2014.06.009] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Revised: 06/18/2014] [Accepted: 06/19/2014] [Indexed: 12/16/2022]
Abstract
Cell-cell and cell-matrix interactions mediated by cell adhesion molecules are important mechanisms controlling cell fate and function. Here, we review recent advances in the implication of the cell adhesion molecules integrins and cadherins in the control of osteoblastogenesis and bone formation. We discuss emerging evidence indicating that signaling pathways mediated by integrins and cadherins and their crosstalk with the Wnt/β-catenin signaling pathway regulate osteogenic differentiation and mechanotransduction. We also offer a comprehensive view of the mechanisms by which some integrins and cadherins control the differentiation of cells of the osteoblast lineage in bone marrow niches. Understanding how specific integrins or cadherins may promote osteogenic cell differentiation, bone formation, and repair may lead to novel therapeutic strategies.
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Affiliation(s)
- Pierre J Marie
- UMR-1132 INSERM and University Paris Diderot, Sorbonne Paris Cité, Paris, 75475 cedex 10, France.
| | - Eric Haÿ
- UMR-1132 INSERM and University Paris Diderot, Sorbonne Paris Cité, Paris, 75475 cedex 10, France
| | - Zuzana Saidak
- UMR-1132 INSERM and University Paris Diderot, Sorbonne Paris Cité, Paris, 75475 cedex 10, France
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28
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Targeting P2 receptors--current progress in treating musculoskeletal diseases. Curr Opin Pharmacol 2014; 16:122-6. [PMID: 24880708 DOI: 10.1016/j.coph.2014.05.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Revised: 05/05/2014] [Accepted: 05/05/2014] [Indexed: 12/12/2022]
Abstract
It is widely recognized that purinergic signalling, extracellular nucleotides acting at purinergic receptors, is the most primitive and ubiquitous signalling system participating in numerous biological processes in almost all tissue types. The P2 receptors, including P2X and P2Y purinoceptor subtypes, have been proposed to play important roles in the musculoskeletal systems since the early 1990s. During the past five years, significant progress in this field has been made; this review will summarize these most recent developments and highlight the pharmaceutical potential from these findings.
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29
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Mechanosensory responses of osteocytes to physiological forces occur along processes and not cell body and require αVβ3 integrin. Proc Natl Acad Sci U S A 2013; 110:21012-7. [PMID: 24324138 DOI: 10.1073/pnas.1321210110] [Citation(s) in RCA: 93] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Osteocytes in the lacunar-canalicular system of the bone are thought to be the cells that sense mechanical loading and transduce mechanical strain into biomechanical responses. The goal of this study was to evaluate the extent to which focal mechanical stimulation of osteocyte cell body and process led to activation of the cells, and determine whether integrin attachments play a role in osteocyte activation. We use a novel Stokesian fluid stimulus probe to hydrodynamically load osteocyte processes vs. cell bodies in murine long bone osteocyte Y4 (MLO-Y4) cells with physiological-level forces <10 pN without probe contact, and measured intracellular Ca(2+) responses. Our results indicate that osteocyte processes are extremely responsive to piconewton-level mechanical loading, whereas the osteocyte cell body and processes with no local attachment sites are not. Ca(2+) signals generated at stimulated sites spread within the processes with average velocity of 5.6 μm/s. Using the near-infrared fluorescence probe IntegriSense 750, we demonstrated that inhibition of αVβ3 integrin attachment sites compromises the response to probe stimulation. Moreover, using apyrase, an extracellular ATP scavenger, we showed that Ca(2+) signaling from the osteocyte process to the cell body was greatly diminished, and thus dependent on ATP-mediated autocrine signaling. These findings are consistent with the hypothesis that osteocytes in situ are highly polarized cells, where mechanotransduction occurs at substrate attachment sites along the processes at force levels predicted to occur at integrin attachment sites in vivo. We also demonstrate the essential role of αVβ3 integrin in osteocyte-polarized mechanosensing and mechanotransduction.
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