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Delsmann J, Eissele J, Simon A, Alimy AR, von Kroge S, Mushumba H, Püschel K, Busse B, Ries C, Amling M, Beil FT, Rolvien T. Alterations in compositional and cellular properties of the subchondral bone are linked to cartilage degeneration in hip osteoarthritis. Osteoarthritis Cartilage 2024; 32:535-547. [PMID: 38403152 DOI: 10.1016/j.joca.2024.01.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 12/21/2023] [Accepted: 01/22/2024] [Indexed: 02/27/2024]
Abstract
OBJECTIVE The subchondral bone is an emerging regulator of osteoarthritis (OA). However, knowledge of how specific subchondral alterations relate to cartilage degeneration remains incomplete. METHOD Femoral heads were obtained from 44 patients with primary OA during total hip arthroplasty and from 30 non-OA controls during autopsy. A multiscale assessment of the central subchondral bone region comprising histomorphometry, quantitative backscattered electron imaging, nanoindentation, and osteocyte lacunocanalicular network characterization was employed. RESULTS In hip OA, thickening of the subchondral bone coincided with a higher number of osteoblasts (controls: 3.7 ± 4.5 mm-1, OA: 16.4 ± 10.2 mm-1, age-adjusted mean difference 10.5 mm-1 [95% CI 4.7 to 16.4], p < 0.001) but a similar number of osteoclasts compared to controls (p = 0.150). Furthermore, higher matrix mineralization heterogeneity (CaWidth, controls: 2.8 ± 0.2 wt%, OA: 3.1 ± 0.3 wt%, age-adjusted mean difference 0.2 wt% [95% CI 0.1 to 0.4], p = 0.011) and lower tissue hardness (controls: 0.69 ± 0.06 GPa, OA: 0.67 ± 0.06 GPa, age-adjusted mean difference -0.05 GPa [95% CI -0.09 to -0.01], p = 0.032) were detected. While no evidence of altered osteocytic perilacunar/canalicular remodeling in terms of fewer osteocyte canaliculi was found in OA, specimens with advanced cartilage degeneration showed a higher number of osteocyte canaliculi and larger lacunocanalicular network area compared to those with low-grade cartilage degeneration. Multiple linear regression models indicated that several subchondral bone properties, especially osteoblast and osteocyte parameters, were closely related to cartilage degeneration (R2 adjusted = 0.561, p < 0.001). CONCLUSION Subchondral bone properties in OA are affected at the compositional, mechanical, and cellular levels. Based on their strong interaction with cartilage degeneration, targeting osteoblasts/osteocytes may be a promising therapeutic OA approach. DATA AND MATERIALS AVAILABILITY All data are available in the main text or the supplementary materials.
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Affiliation(s)
- Julian Delsmann
- Department of Trauma and Orthopaedic Surgery, Division of Orthopaedics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Julian Eissele
- Department of Trauma and Orthopaedic Surgery, Division of Orthopaedics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Alexander Simon
- Department of Trauma and Orthopaedic Surgery, Division of Orthopaedics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Assil-Ramin Alimy
- Department of Trauma and Orthopaedic Surgery, Division of Orthopaedics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Simon von Kroge
- Department of Trauma and Orthopaedic Surgery, Division of Orthopaedics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Herbert Mushumba
- Department of Legal Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Klaus Püschel
- Department of Legal Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Björn Busse
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Christian Ries
- Department of Trauma and Orthopaedic Surgery, Division of Orthopaedics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Michael Amling
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Frank Timo Beil
- Department of Trauma and Orthopaedic Surgery, Division of Orthopaedics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Tim Rolvien
- Department of Trauma and Orthopaedic Surgery, Division of Orthopaedics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
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Vercher-Martínez A, Megías R, Belda R, Vargas P, Giner E. Estimation of the in-plane ultimate stress of lamellar tissue as a function of bone mineral density and osteocyte lacunae porosity. Comput Methods Programs Biomed 2024; 248:108120. [PMID: 38492277 DOI: 10.1016/j.cmpb.2024.108120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 03/05/2024] [Accepted: 03/06/2024] [Indexed: 03/18/2024]
Abstract
BACKGROUND AND OBJECTIVE Detailed finite element models based on medical images (μ-CT) are commonly used to analyze the mechanical behavior of bone at microscale. In order to simulate the tissue failure onset, isotropic failure criteria of lamellar tissue are often used, despite its non-isotropic and heterogeneous nature. The main goal of the present work is to estimate the in-plane ultimate stress of lamellar bone, considering the influence of mineral content and the porosity due to the osteocyte lacunae concentration. METHODS To this aim, a representative volume cell of lamellar tissue is modeled numerically, including: (1) non-isotropic elastic properties of tissue as a function of the bone mineral density and (2) explicit modeling of the osteocyte lacunae, considering the range of porosity content, size and orientation of ellipsoid-shaped lacunae. Firstly, the element size for the finite element models have been defined from a preliminary convergence analysis. Bounds on the ultimate stress of non-porous lamellar tissue are estimated for two values of bone mineral density, considering the results of tensile and compressive tests of wet osteons from the literature. Subsequently, the ultimate stress of lamellar tissue considering several values of micro-porosity is addressed. RESULTS Results obtained in this work show that the strength of lamellar bone decreases exponentially with the increase of lacunae porosity concentration. Ultimate stress of non-porous tissue (p=0%) increases with high mineral content, reaching a value of S¯transc=355.40±39.80 MPa for compression in the transversal direction of the fiber bundles, being BMD=1.246g/cm3. The mean value for the longitudinal to transverse strength ratio evaluated for porosity p=0%,1% and 5% and a mineral content BMD=1.2g/cm3, is 2.47:1 for tension and 1.55:1 for compression. These values are in agreement with literature. CONCLUSIONS Osteocyte lacunae act as stress concentrators, acting as potential stimulus for the bone regeneration process. A novel micromechanical model for the in-plane ultimate stress of lamellar tissue as a function of mineral content and lacunae concentration is presented. Additional considerations about the intralamellar shear stress evolution are also given.
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Affiliation(s)
- Ana Vercher-Martínez
- Dept. de Ingeniería Mecánica y de Materiales, Instituto de Ingeniería Mecánica y Biomecánica de Valencia - I2MB, Universitat Politècnica de València, Camino de Vera, Building 5E, 46022 Valencia, Spain.
| | - Raquel Megías
- Dept. de Ingeniería Mecánica y de Materiales, Instituto de Ingeniería Mecánica y Biomecánica de Valencia - I2MB, Universitat Politècnica de València, Camino de Vera, Building 5E, 46022 Valencia, Spain
| | - Ricardo Belda
- Dept. de Ingeniería Mecánica y de Materiales, Instituto de Ingeniería Mecánica y Biomecánica de Valencia - I2MB, Universitat Politècnica de València, Camino de Vera, Building 5E, 46022 Valencia, Spain
| | - Pablo Vargas
- Dept. de Ingeniería Mecánica y de Materiales, Instituto de Ingeniería Mecánica y Biomecánica de Valencia - I2MB, Universitat Politècnica de València, Camino de Vera, Building 5E, 46022 Valencia, Spain
| | - Eugenio Giner
- Dept. de Ingeniería Mecánica y de Materiales, Instituto de Ingeniería Mecánica y Biomecánica de Valencia - I2MB, Universitat Politècnica de València, Camino de Vera, Building 5E, 46022 Valencia, Spain
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Hering RN, von Kroge S, Delsmann J, Simon A, Ondruschka B, Püschel K, Schmidt FN, Rolvien T. Pronounced cortical porosity and sex-specific patterns of increased bone and osteocyte lacunar mineralization characterize the human distal fibula with aging. Bone 2024; 182:117068. [PMID: 38458304 DOI: 10.1016/j.bone.2024.117068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 03/01/2024] [Accepted: 03/05/2024] [Indexed: 03/10/2024]
Abstract
The high occurrence of distal fibula fractures among older women suggests a potential link to impaired bone health. Here we used a multiscale imaging approach to investigate the microarchitecture, mineralization, and biomechanics of the human distal fibula in relation to age and sex. Micro-computed tomography was performed to analyze the local volumetric bone mineral density and various microarchitectural parameters of the trabecular and the cortical compartment. Bone mineral density distribution and osteocyte lacunar parameters were quantified using quantitative backscattered electron imaging in periosteal, endocortical, and trabecular regions. Additionally, cortical hardness and Young's modulus were assessed by nanoindentation. While cortical porosity strongly increased with age independent of sex, trabecular microarchitecture remained stable. Notably, nearly half of the specimens showed non-bony hypermineralized tissue located at the periosteum, similar to that previously detected in the femoral neck, with no consistent association with advanced age. Independent of this finding, cortical and trabecular mineralization, i.e., mean calcium content, as well as endocortical tissue hardness increased with age in males but not females. Importantly, we also observed mineralized osteocyte lacunae that increased with age specifically in females. In conclusion, our results indicate that skeletal aging of the distal fibula is signified not only by pronounced cortical porosity but also by an increase in mineralized osteocyte lacunae in females. These findings may provide an explanation for the increased occurrence of ankle fractures in older women.
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Affiliation(s)
- Robin-Nicolas Hering
- Department of Trauma and Orthopaedic Surgery, Division of Orthopaedics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Institute of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Simon von Kroge
- Department of Trauma and Orthopaedic Surgery, Division of Orthopaedics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Institute of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Julian Delsmann
- Department of Trauma and Orthopaedic Surgery, Division of Orthopaedics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Alexander Simon
- Department of Trauma and Orthopaedic Surgery, Division of Orthopaedics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Benjamin Ondruschka
- Institute of Legal Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Klaus Püschel
- Institute of Legal Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Felix Nikolai Schmidt
- Institute of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Tim Rolvien
- Department of Trauma and Orthopaedic Surgery, Division of Orthopaedics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
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Pan S, Hou Z, Liu J, Xu L. Numerical calculation of streaming potential around osteocytes under human gait loading. Comput Biol Med 2024; 172:108247. [PMID: 38493605 DOI: 10.1016/j.compbiomed.2024.108247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 03/05/2024] [Accepted: 03/06/2024] [Indexed: 03/19/2024]
Abstract
Streaming potential is a type of stress-generated potential in bone that affects the electrical environment of osteocytes and may play a role in bone remodeling. Because the electrical environment around osteocytes has been difficult to measure experimentally until now, a numerical solid-liquid-streaming potential coupling method was proposed to analyze the streaming potential generated by bone deformation in the lacunae and canaliculus network (LCN) of the bone. Using this method, the cellular shear stress caused by liquid flow on the osteocyte surface was first calculated, and the results were consistent with those reported in the literature. Subsequently, the streaming potentials in the LCN caused by bone matrix deformation under an external gait load were calculated numerically. The results showed that the streaming potential increased slowly in the lacuna and relatively rapidly in the canaliculus and that the streaming potential increased with a decrease in the radius or an increase in the length of the canaliculus. The results also showed that relatively large gaps between the lacunae and osteocytes could induce higher streaming potentials under the same loading.
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Affiliation(s)
- Shaozhe Pan
- Department of Mechanics, School of Mechanical Engineering, Tianjin University, Tianjin 300072, China
| | - Zhende Hou
- Department of Mechanics, School of Mechanical Engineering, Tianjin University, Tianjin 300072, China.
| | | | - Lianyun Xu
- Department of Mechanics, School of Mechanical Engineering, Tianjin University, Tianjin 300072, China
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Fernandes Da Costa C, Attik N, Gauthier R. Influence of intramedullary pressure on Lacuno-Canalicular fluid flow: A systematic review. Acta Biomater 2024; 178:41-49. [PMID: 38484832 DOI: 10.1016/j.actbio.2024.03.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 03/01/2024] [Accepted: 03/06/2024] [Indexed: 03/24/2024]
Abstract
While most of current models investigating bone remodelling are based on matrix deformation, intramedullary pressure also plays a role. Bone remodelling is orchestrated by the Lacuno-Canalicular Network (LCN) fluid-flow. The aim of this review was hence to assess the influence of intramedullary pressure on the fluid circulation within the LCN. Three databases (Science Direct, Web of Science, and PubMed) were used. The first phase of the search returned 731 articles, of which 9 respected the inclusion/exclusion criteria and were included. These studies confirm the association between intramedullary pressure and fluid dynamics in the LCN. Among the included studies, 7 experimental studies using animal models and 2 numerical models were found. The studies were then ranked according to the nature of the applied loading, either axial compression or direct cyclic intramedullary pressure. The current review revealed that there is an influence of intramedullary pressure on LCN fluid dynamics and that this influence depends on the magnitude and the frequency of the applied pressure. Two studies confirmed that the influence was effective even without bone matrix deformation. While intramedullary pressure is closely associated with LCN fluid, there is a severe lack of studies on this topic. STATEMENT OF SIGNIFICANCE: Since the 1990's, numerical models developed to investigate fluid flow in bone submicrometric porous network are based on the flow induced by matrix deformation. Bone fluid flow is known to be involved in cells stimulation and hence directly influences bone remodeling. Different studies have shown that intramedullary pressure is also associated with bone mechanosensitive adaptation. This pressure is developed in bone due to blood circulation and is increased during loading or muscle stimulation. The current article reviews the studies investigating the influence of this pressure on bone porous fluid flow. They show that fluid flow is involved by this pressure even without bone matrix deformation. The current review article highlights the severe lack of studies about this mechanism.
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Affiliation(s)
- Cassandra Fernandes Da Costa
- UMR CNRS 5615, Laboratoire des Multimatériaux et Interfaces, Université de Lyon, Université Claude Bernard Lyon 1, Lyon 69372 CEDEX 08, France; CNRS, INSA Lyon, MATEIS, UMR5510, Université de Lyon, Université Claude Bernard Lyon 1, 7 avenue Jean Capelle, Villeurbanne CEDEX 69621, France
| | - Nina Attik
- UMR CNRS 5615, Laboratoire des Multimatériaux et Interfaces, Université de Lyon, Université Claude Bernard Lyon 1, Lyon 69372 CEDEX 08, France; Faculté d'Odontologie, Université de Lyon, Université Claude Bernard Lyon 1, Lyon 69372 CEDEX 08, France.
| | - Remy Gauthier
- CNRS, INSA Lyon, MATEIS, UMR5510, Université de Lyon, Université Claude Bernard Lyon 1, 7 avenue Jean Capelle, Villeurbanne CEDEX 69621, France.
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Che J, Chen X, Ren W, Shang P. PTH 1-34 reduced apoptosis of MLO-Y4 osteocyte-like cells by activating autophagy and inhibiting ER stress under RPM conditions. Eur J Pharmacol 2024; 967:176364. [PMID: 38316249 DOI: 10.1016/j.ejphar.2024.176364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 01/26/2024] [Accepted: 01/29/2024] [Indexed: 02/07/2024]
Abstract
Osteocytes, as mechanosensitive cells residing within bone tissue, hold a pivotal role in averting the occurrence and progression of osteoporosis. The apoptosis of osteocytes induced by unloading is one of the contributing factors to osteoporosis, although the underlying molecular mechanisms have not been fully elucidated. PTH 1-34 is known to promote bone formation and inhibit bone loss by targeting osteoblasts and osteocytes. However, it is not known whether PTH 1-34 can inhibit osteocyte apoptosis under unloading conditions and the molecular mechanisms involved. In this study, we employed a Random Positioning Machine (RPM) to emulate unloading conditions and cultured MLO-Y4 osteocyte-like cells, in order to unravel the mechanisms through which PTH 1-34 constrains osteocyte apoptosis amidst unloading circumstances. Our findings revealed that PTH 1-34 activated autophagy while suppressing endoplasmic reticulum stress by curtailing the generation of reactive oxygen species (ROS) in MLO-Y4 osteocyte-like cells during unloading conditions. By shedding light on the osteoporosis triggered by skeletal unloading, this study contributes vital insights that may pave the way for the development of pharmacological interventions.
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Affiliation(s)
- Jingmin Che
- Shaanxi Provincial Key Laboratory of Infection and Immune Diseases, Shaanxi Provincial People's Hospital, Xi'an, Shaanxi, China; Research & Development Institute of Northwestern Polytechnical University in Shenzhen, Shenzhen, Guangdong, China; Key Laboratory for Space Bioscience and Biotechnology, Northwestern Polytechnical University, Xi'an, Shaanxi, China.
| | - Xin Chen
- Research & Development Institute of Northwestern Polytechnical University in Shenzhen, Shenzhen, Guangdong, China; School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, China; Key Laboratory for Space Bioscience and Biotechnology, Northwestern Polytechnical University, Xi'an, Shaanxi, China
| | - Weihao Ren
- Research & Development Institute of Northwestern Polytechnical University in Shenzhen, Shenzhen, Guangdong, China; School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, China; Key Laboratory for Space Bioscience and Biotechnology, Northwestern Polytechnical University, Xi'an, Shaanxi, China
| | - Peng Shang
- Research & Development Institute of Northwestern Polytechnical University in Shenzhen, Shenzhen, Guangdong, China; Key Laboratory for Space Bioscience and Biotechnology, Northwestern Polytechnical University, Xi'an, Shaanxi, China.
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Hegarty-Cremer SGD, Borggaard XG, Andreasen CM, van der Eerden BCJ, Simpson MJ, Andersen TL, Buenzli PR. How osteons form: A quantitative hypothesis-testing analysis of cortical pore filling and wall asymmetry. Bone 2024; 180:116998. [PMID: 38184100 DOI: 10.1016/j.bone.2023.116998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 12/06/2023] [Accepted: 12/24/2023] [Indexed: 01/08/2024]
Abstract
Osteon morphology provides valuable information about the interplay between different processes involved in bone remodelling. The correct quantitative interpretation of these morphological features is challenging due to the complexity of interactions between osteoblast behaviour, and the evolving geometry of cortical pores during pore closing. We present a combined experimental and mathematical modelling study to provide insights into bone formation mechanisms during cortical bone remodelling based on histological cross-sections of quiescent human osteons and hypothesis-testing analyses. We introduce wall thickness asymmetry as a measure of the local asymmetry of bone formation within an osteon and examine the frequency distribution of wall thickness asymmetry in cortical osteons from human iliac crest bone samples from women 16-78 years old. Our measurements show that most osteons possess some degree of asymmetry, and that the average degree of osteon asymmetry in cortical bone evolves with age. We then propose a comprehensive mathematical model of cortical pore filling that includes osteoblast secretory activity, osteoblast elimination, osteoblast embedment as osteocytes, and osteoblast crowding and redistribution along the bone surface. The mathematical model is first calibrated to symmetric osteon data, and then used to test three mechanisms of asymmetric wall formation against osteon data: (i) delays in the onset of infilling around the cement line; (ii) heterogeneous osteoblastogenesis around the bone perimeter; and (iii) heterogeneous osteoblast secretory rate around the bone perimeter. Our results suggest that wall thickness asymmetry due to off-centred Haversian pores within osteons, and that nonuniform lamellar thicknesses within osteons are important morphological features that can indicate the prevalence of specific asymmetry-generating mechanisms. This has significant implications for the study of disruptions of bone formation as it could indicate what biological bone formation processes may become disrupted with age or disease.
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Affiliation(s)
- Solene G D Hegarty-Cremer
- School of Mathematical Sciences, Queensland University of Technology (QUT), Brisbane, Australia; Department of Mathematics and Statistics, The University of Montreal, Montreal, Canada
| | - Xenia G Borggaard
- Clinical Cell Biology, Pathology Research Unit, Dept. of Clinical Research, and Dept. of Molecular Medicine, University of Southern Denmark, Odense, Denmark; Dept. of Pathology, Odense University Hospital, Odense, Denmark
| | - Christina M Andreasen
- Clinical Cell Biology, Pathology Research Unit, Dept. of Clinical Research, and Dept. of Molecular Medicine, University of Southern Denmark, Odense, Denmark; Dept. of Pathology, Odense University Hospital, Odense, Denmark
| | | | - Matthew J Simpson
- School of Mathematical Sciences, Queensland University of Technology (QUT), Brisbane, Australia
| | - Thomas L Andersen
- Clinical Cell Biology, Pathology Research Unit, Dept. of Clinical Research, and Dept. of Molecular Medicine, University of Southern Denmark, Odense, Denmark; Dept. of Pathology, Odense University Hospital, Odense, Denmark; Dept. of Forensic Medicine, Aarhus University, Aarhus, Denmark
| | - Pascal R Buenzli
- School of Mathematical Sciences, Queensland University of Technology (QUT), Brisbane, Australia.
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Zhang X, Yang Z, Xu Q, Xu C, Shi W, Pang R, Zhang K, Liang X, Li H, Li Z, Zhang H. Dexamethasone Induced Osteocyte Apoptosis in Steroid-Induced Femoral Head Osteonecrosis through ROS-Mediated Oxidative Stress. Orthop Surg 2024; 16:733-744. [PMID: 38384174 PMCID: PMC10925516 DOI: 10.1111/os.14010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 01/16/2024] [Accepted: 01/18/2024] [Indexed: 02/23/2024] Open
Abstract
OBJECTIVE Glucocorticoid (GC) overuse is strongly associated with steroid-induced osteonecrosis of the femoral head (SINFH). However, the underlying mechanism of SINFH remains unclear. This study aims to investigate the effect of dexamethasone (Dex)-induced oxidative stress on osteocyte apoptosis and the underlying mechanisms. METHODS Ten patients with SINFH and 10 patients with developmental dysplasia of the hips (DDH) were enrolled in our study. Sixty rats were randomly assigned to the Control, Dex, Dex + N-Acetyl-L-cysteine (NAC), Dex + Dibenziodolium chloride (DPI), NAC, and DPI groups. Magnetic resonance imaging (MRI) was used to examine edema in the femoral head of rats. Histopathological staining was performed to assess osteonecrosis. Immunofluorescence staining with TUNEL and 8-OHdG was conducted to evaluate osteocyte apoptosis and oxidative damage. Immunohistochemical staining was carried out to detect the expression of NOX1, NOX2, and NOX4. Viability and apoptosis of MLO-Y4 cells were measured using the CCK-8 assay and TUNEL staining. 8-OHdG staining was conducted to detect oxidative stress. 2',7'-Dichlorodihydrofluorescein diacetate (DCFH-DA) staining was performed to measure reactive oxygen species (ROS). The expression of NOX1, NOX2, and NOX4 in MLO-Y4 cells was analyzed by Western blotting. Multiple comparisons were performed using one-way analysis of variance (ANOVA). RESULTS In patients and the rat model, hematoxylin-eosin (HE) staining revealed a significantly higher rate of empty lacunae in the SINFH group than in the DDH group. Immunofluorescence staining indicated a significant increase in TUNEL-positive cells and 8-OHdG-positive cells in the SINFH group compared to the DDH group. Immunohistochemical staining demonstrated a significant increase in the expression of NOX1, NOX2, and NOX4 proteins in SINFH patients compared to DDH patients. Moreover, immunohistochemical staining showed a significant increase in the proportion of NOX2-positive cells compared to the Control group in the femoral head of rats. In vitro, Dex significantly inhibited the viability of osteocyte cells and induced apoptosis. After Dex treatment, the intracellular ROS level increased. However, Dex treatment did not alter the expression of NOX proteins in vitro. Additionally, NAC and DPI inhibited the generation of intracellular ROS and partially alleviated osteocyte apoptosis in vivo and in vitro. CONCLUSION This study demonstrates that GC promotes apoptosis of osteocyte cells through ROS-induced oxidative stress. Furthermore, we found that the increased expression of NOXs induced by GC serves as an important source of ROS generation.
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Affiliation(s)
- Xinglong Zhang
- Department of OrthopaedicsGeneral Hospital of Tianjin Medical UniversityTianjinChina
- Department of OrthopaedicsTianjin Nankai HospitalTianjinChina
| | - Zhenhuan Yang
- Department of OrthopaedicsGeneral Hospital of Tianjin Medical UniversityTianjinChina
| | - Qian Xu
- School of Integrative MedicineTianjin University of Traditional Chinese MedicineTianjinChina
| | - Chunlei Xu
- Department of OrthopaedicsGeneral Hospital of Tianjin Medical UniversityTianjinChina
| | - Wei Shi
- Department of OrthopaedicsGeneral Hospital of Tianjin Medical UniversityTianjinChina
| | - Ran Pang
- Department of OrthopaedicsGeneral Hospital of Tianjin Medical UniversityTianjinChina
- Department of OrthopaedicsTianjin Nankai HospitalTianjinChina
| | - Kai Zhang
- Department of OrthopaedicsGeneral Hospital of Tianjin Medical UniversityTianjinChina
| | - Xinyu Liang
- Department of OrthopaedicsGeneral Hospital of Tianjin Medical UniversityTianjinChina
| | - Hui Li
- Department of OrthopaedicsGeneral Hospital of Tianjin Medical UniversityTianjinChina
| | - Zhijun Li
- Department of OrthopaedicsGeneral Hospital of Tianjin Medical UniversityTianjinChina
| | - Huafeng Zhang
- Department of OrthopaedicsGeneral Hospital of Tianjin Medical UniversityTianjinChina
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9
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Meng Y, Qiu SQ, Wang Q, Zuo JL. Regulator of G protein signalling 18 promotes osteocyte proliferation by activating the extracellular signal‑regulated kinase signalling pathway. Int J Mol Med 2024; 53:22. [PMID: 38214344 PMCID: PMC10836495 DOI: 10.3892/ijmm.2024.5346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Accepted: 11/14/2023] [Indexed: 01/13/2024] Open
Abstract
Osteocyte function is critical for metabolism, remodelling and regeneration of bone tissue. In the present study, the roles of regulator of G protein signalling 18 (RGS18) were assessed in the regulation of osteocyte proliferation and bone formation. Target genes and signalling pathways were screened using the Gene Expression Omnibus (GEO) database and Gene Set Enrichment Analysis (GSEA). The function of RGS18 and the associated mechanisms were analysed by Cell Counting Kit 8 assay, 5‑ethynyl‑2'‑deoxyuridine assay, flow cytometry, reverse transcription‑quantitative PCR, western blotting and immunostaining. Overlap analysis of acutely injured subjects (AIS) and healthy volunteers (HVs) from the GSE93138 and GSE93215 datasets of the GEO database identified four genes: KIAA0825, ANXA3, RGS18 and LIPN. Notably, RGS18 was more highly expressed in peripheral blood samples from AIS than in those from HVs. Furthermore, RGS18 overexpression promoted MLO‑Y4 and MC3T3‑E1 cell viability, proliferation and S‑phase arrest, but inhibited apoptosis by suppressing caspase‑3/9 cleavage. Silencing RGS18 exerted the opposite effects. GSEA of GSE93138 revealed that RGS18 has the ability to regulate MAPK signalling. Treatment with the MEK1/2 inhibitor PD98059 reversed the RGS18 overexpression‑induced osteocyte proliferation, and treatment with the ERK1/2 activator 12‑O‑tetradecanoylphorbol‑13‑acetate reversed the effects of RGS18 silencing on osteocyte proliferation. In conclusion, RGS18 may contribute to osteocyte proliferation and bone fracture healing via activation of ERK signalling.
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Affiliation(s)
- Yong Meng
- Department of Orthopaedics, The Fifth Affiliated Hospital Jinan University, Heyuan, Guangdong 517000, P.R. China
| | - Si-Qiang Qiu
- Department of Spine Surgery, The Fourth People's Hospital of Jinan, Jinan, Shandong 250031, P.R. China
| | - Qiang Wang
- Department of Spine Surgery, The Fourth People's Hospital of Jinan, Jinan, Shandong 250031, P.R. China
| | - Jin-Liang Zuo
- Department of Spine Surgery, The Fourth People's Hospital of Jinan, Jinan, Shandong 250031, P.R. China
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10
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Schurman CA, Kaya S, Dole N, Luna NMM, Castillo N, Potter R, Rose JP, Bons J, King CD, Burton JB, Schilling B, Melov S, Tang S, Schaible E, Alliston T. Aging impairs the osteocytic regulation of collagen integrity and bone quality. Bone Res 2024; 12:13. [PMID: 38409111 PMCID: PMC10897167 DOI: 10.1038/s41413-023-00303-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 10/31/2023] [Accepted: 11/13/2023] [Indexed: 02/28/2024] Open
Abstract
Poor bone quality is a major factor in skeletal fragility in elderly individuals. The molecular mechanisms that establish and maintain bone quality, independent of bone mass, are unknown but are thought to be primarily determined by osteocytes. We hypothesize that the age-related decline in bone quality results from the suppression of osteocyte perilacunar/canalicular remodeling (PLR), which maintains bone material properties. We examined bones from young and aged mice with osteocyte-intrinsic repression of TGFβ signaling (TβRIIocy-/-) that suppresses PLR. The control aged bone displayed decreased TGFβ signaling and PLR, but aging did not worsen the existing PLR suppression in male TβRIIocy-/- bone. This relationship impacted the behavior of collagen material at the nanoscale and tissue scale in macromechanical tests. The effects of age on bone mass, density, and mineral material behavior were independent of osteocytic TGFβ. We determined that the decline in bone quality with age arises from the loss of osteocyte function and the loss of TGFβ-dependent maintenance of collagen integrity.
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Affiliation(s)
- Charles A Schurman
- Department of Orthopaedic Surgery, University of California, San Francisco, CA, 94143, USA
- UC Berkeley/UCSF Graduate Program in Bioengineering, San Francisco, CA, 94143, USA
- Buck Institute for Research on Aging, Novato, CA, 94945, USA
| | - Serra Kaya
- Department of Orthopaedic Surgery, University of California, San Francisco, CA, 94143, USA
| | - Neha Dole
- Department of Orthopaedic Surgery, University of California, San Francisco, CA, 94143, USA
| | - Nadja M Maldonado Luna
- Department of Orthopaedic Surgery, University of California, San Francisco, CA, 94143, USA
- UC Berkeley/UCSF Graduate Program in Bioengineering, San Francisco, CA, 94143, USA
| | - Natalia Castillo
- Department of Orthopaedic Surgery, University of California, San Francisco, CA, 94143, USA
| | - Ryan Potter
- Washington University in St Louis, Department of Orthopedics, St. Louis, MO, 63130, USA
| | - Jacob P Rose
- Buck Institute for Research on Aging, Novato, CA, 94945, USA
| | - Joanna Bons
- Buck Institute for Research on Aging, Novato, CA, 94945, USA
| | | | - Jordan B Burton
- Buck Institute for Research on Aging, Novato, CA, 94945, USA
| | | | - Simon Melov
- Buck Institute for Research on Aging, Novato, CA, 94945, USA
| | - Simon Tang
- Washington University in St Louis, Department of Orthopedics, St. Louis, MO, 63130, USA
| | - Eric Schaible
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Tamara Alliston
- Department of Orthopaedic Surgery, University of California, San Francisco, CA, 94143, USA.
- UC Berkeley/UCSF Graduate Program in Bioengineering, San Francisco, CA, 94143, USA.
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11
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Wein MN. Blood and bones: Mechanical cues and Hippo signaling drive vascular invasion during limb formation. Dev Cell 2024; 59:173-174. [PMID: 38262346 DOI: 10.1016/j.devcel.2023.12.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 12/15/2023] [Accepted: 12/15/2023] [Indexed: 01/25/2024]
Abstract
Although mechanical cues are known to influence the postnatal skeleton, the impact of bone cell mechano-transduction on early skeletal development remains less clear. In this issue of Developmental Cell, Collins et al. (2023) report that YAP/TAZ deletion in osteoblast precursors reduces Cxcl12 expression, leading to defects in bone vascularization.
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Affiliation(s)
- Marc N Wein
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA; Broad Institute of MIT and Harvard, Cambridge, MA, USA; Harvard Stem Cell Institute, Cambridge, MA, USA.
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12
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Mochetti MM, Pessoa AS, Tokuhara CK, Sanches MLR, Senger C, Moreira MAA, Oliveira RC. Red light-emitting diode therapy minimizes the functional deleterious effects of the antiretroviral ritonavir on osteoblasts in vitro. Lasers Med Sci 2024; 39:34. [PMID: 38231300 DOI: 10.1007/s10103-024-03979-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Accepted: 01/04/2024] [Indexed: 01/18/2024]
Abstract
PURPOSE Long-term human immunodeficiency virus (HIV)-infected patients are considered at higher risk for osteoporosis. Among the various causes that lead these patients to lower bone health, there is the use of antiretroviral drugs (ARVs), especially protease inhibitors (PI), such as ritonavir (RTV). In this context, emerge the potential benefits of LED therapy, whose effects on bone cells are currently being extensively studied, showing a modulation in cell differentiation. However, it remains unclear if photobiostimulation might interfere with RTV effects on osteoblast differentiation. METHODS In the present study, we investigated the effects of red LED (625 nm) irradiation (15 mW/cm2, 0.2 J/cm2, and 8 mW/cm2, 0.12 J/cm2) on osteoblast cell line MC3T3-E1 treated with RTV (2.5, 5, and 10 μg/mL). RESULTS Our results indicated that red LED irradiation was able to reverse, or at least minimize, the deleterious effects of RTV on the osteoblasts. Neither the ARV treatments 5 and 10 μg/mL (104.4% and 95.01%) nor the LED protocols (100.3% and 105.7%) statistically altered cell viability, assessed by the MTT assay. Also, the alkaline phosphatase activity and mineralization showed a decrease in osteoblast activity followed by ARV exposure (39.3-73%), which was attenuated by LED in more than 70% with statistical significance (p < 0.05). CONCLUSION In conclusion, photobiostimulation with red LED at 625 nm was associated with improved beneficial biological effects as a potential inducer of osteogenic activity on RTV-affected cells. This is the first study that investigated the benefits of red LED irradiation over ARV-treated in vitro osteoblasts.
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Affiliation(s)
- Matheus Menão Mochetti
- Medicine Course, Bauru School of Dentistry, University of São Paulo, Bauru, São Paulo, Brazil
- Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Al. Octávio Pinheiro Brisolla, 9-75, Bauru, São Paulo, 17012-901, Brazil
| | - Adriano Souza Pessoa
- Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Al. Octávio Pinheiro Brisolla, 9-75, Bauru, São Paulo, 17012-901, Brazil
| | | | - Mariana Liessa Rovis Sanches
- Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Al. Octávio Pinheiro Brisolla, 9-75, Bauru, São Paulo, 17012-901, Brazil
| | - Cassia Senger
- Medicine Course, Bauru School of Dentistry, University of São Paulo, Bauru, São Paulo, Brazil
| | - Maria Aparecida Andrade Moreira
- Department of Pediatric Dentistry, Orthodontics and Public Health, Bauru School of Dentistry, University of São Paulo, Bauru, São Paulo, Brazil
| | - Rodrigo Cardoso Oliveira
- Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Al. Octávio Pinheiro Brisolla, 9-75, Bauru, São Paulo, 17012-901, Brazil.
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13
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Soltani L, Varmira K, Nazari M. Comparison of the differentiation of ovine fetal bone-marrow mesenchymal stem cells towards osteocytes on chitosan/alginate/CuO-NPs and chitosan/alginate/FeO-NPs scaffolds. Sci Rep 2024; 14:161. [PMID: 38168144 PMCID: PMC10762099 DOI: 10.1038/s41598-023-50664-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 12/22/2023] [Indexed: 01/05/2024] Open
Abstract
In the current study, the creation of a chitosan/alginate scaffold hydrogel with and without FeO-NPs or CuO-NPs was studied. From fetal ovine bone marrow mesenchymal stem cells (BM-MSCs) were isolated and cultivated. Their differentiation into osteocyte and adipose cells was investigated. Also, on the scaffolds, cytotoxicity and apoptosis were studied. To investigate the differentiation, treatment groups include: (1) BM-MSCs were plated in DMEM culture medium with high glucose containing 10% FBS and antibiotics (negative control); (2) BM-MSCs were plated in osteogenic differentiation medium (positive control); (3) positive control group + FeO-NPs, (4) positive control group + CuO-NPs; (5) BM-MSCs were plated in osteogenic differentiation medium on chitosan/alginate scaffold; (6) BM-MSCs were plated in osteogenic differentiation medium on chitosan/alginate/FeO-NPs scaffold; and (7) BM-MSCs were plated in osteogenic differentiation medium on chitosan/alginate/CuO-NPs scaffold. Alkaline phosphatase enzyme concentrations, mineralization rate using a calcium kit, and mineralization measurement by alizarin staining quantification were evaluated after 21 days of culture. In addition, qRT-PCR was used to assess the expression of the ALP, ColA, and Runx2 genes. When compared to other treatment groups, the addition of CuO-NPs in the chitosan/alginate hydrogel significantly increased the expression of the ColA and Runx2 genes (p < 0.05). However, there was no significant difference between the chitosan/alginate hydrogel groups containing FeO-NPs and CuO-NPs in the expression of the ALP gene. It appears that the addition of nanoparticles, in particular CuO-NPs, has made the chitosan/alginate scaffold more effective in supporting osteocyte differentiation.
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Affiliation(s)
- Leila Soltani
- Department of Animal Sciences, College of Agriculture and Natural Resources, Razi University, Kermanshah, 67144-14971, Iran.
| | - Kambiz Varmira
- Research Center of Oils and Fats, Kermanshah University of Medical Sciences, Kermanshah, Iran.
| | - Maryam Nazari
- Applied Chemistry Department, Faculty of Chemistry, Razi University, Kermanshah, Iran
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14
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Soltani L, Ghaneialvar H, Abbasi N, Bayat P, Nazari M. Chitosan/alginate scaffold enhanced with Berberis vulgaris extract for osteocyte differentiation of ovine fetal stem cells. Cell Biochem Funct 2024; 42:e3924. [PMID: 38269507 DOI: 10.1002/cbf.3924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2023] [Revised: 01/03/2024] [Accepted: 01/04/2024] [Indexed: 01/26/2024]
Abstract
Designing biocompatible polymers using plant derivatives can be extremely useful in tissue engineering, nanomedicine, and many other fields of medicine. In this study, it was first looked into how chitosan/alginate scaffolds were made and characterized in the presence of berberine and barberry fruit extract. Second, the process of proliferation and differentiation of ovine fetal BM-MSCs (bone marrow-mesenchymal stem cells) was assessed on these scaffolds after BM-MSCs were extracted and confirmed by developing into osteocyte and adipose cells. To investigate the differentiation, treatment groups include (1) ovine fetal BM-MSCs were plated in Dulbecco's modified eagle medium culture medium with high glucose containing 10% fetal bovine serum and antibiotics (negative control), (2) ovine fetal BM-MSCs were plated in osteogenic differentiation medium (positive control group), (3) positive control group + barberry fruit extract, (4) positive control group + berberine, (5) ovine fetal BM-MSCs were plated in osteogenic differentiation medium on chitosan/alginate scaffold (hydrogel group), (6) ovine fetal BM-MSCs were plated in osteogenic differentiation medium on chitosan/alginate/barberry fruit extract scaffold (hydrogel group containing barberry fruit extract), and (7) ovine fetal BM-MSCs were plated in osteogenic differentiation medium on chitosan/alginate/berberine scaffold (hydrogel group containing berberine). Alkaline phosphatase (ALP) enzyme concentrations, mineralization rate using a calcium kit, and mineralization measurement by alizarin staining quantification were all found after 21 days of culture. In addition, real-time quantitative reverse transcription polymerase chain reaction was used to assess the expression of the ALP, COL1A2, and Runx2 genes. Days 5 and 7 had the lowest water absorption by the hydrogel scaffold containing barberry extract, which was significant in comparison to other groups (p < .05). Among the hydrogel scaffolds under study, the one containing barberry extract exhibited the lowest tensile strength, and this difference was statistically significant (p < .05). The chitosan/alginate hydrogel has the highest tensile strength of all of them. In comparison to the control and other treatment groups, the inclusion of berberine in the chitosan/alginate hydrogel significantly increased the expression of the ALP, Runx2, and COL1A2 genes (p < .05). The osteocyte differentiation of mesenchymal stem cells in in vitro settings appears to have been enhanced by the inclusion of berberine in the chitosan/alginate scaffold.
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Affiliation(s)
- Leila Soltani
- Department of Animal Sciences, Faculty of Agriculture, Razi University, Kermanshah, Iran
| | - Hori Ghaneialvar
- Biotechnology and Medicinal Plants Research Center, Ilam University of Medical Sciences, Ilam, Iran
- Department of Clinical Biochemistry, Medical School, Ilam University of Medical Sciences, Ilam, Iran
| | - Naser Abbasi
- Biotechnology and Medicinal Plants Research Center, Ilam University of Medical Sciences, Ilam, Iran
- Department of Pharmacology, Medical School, Ilam University of Medical Sciences, Ilam, Iran
| | - Parvaneh Bayat
- Department of Chemistry, Isfahan University of Technology, Ilam, Iran
| | - Maryam Nazari
- Applied Chemistry Department, Faculty of Chemistry, Razi University, Kermanshah, Iran
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15
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Tan WH, Winkler C. Lineage Tracing of Bone Cells in the Regenerating Fin and During Repair of Bone Lesions. Methods Mol Biol 2024; 2707:99-110. [PMID: 37668907 DOI: 10.1007/978-1-0716-3401-1_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/06/2023]
Abstract
Small teleost fishes such as zebrafish and medaka show remarkable regeneration capabilities upon tissue injury or amputation. To elucidate cellular mechanisms of teleost tissue repair and regeneration processes, the Cre/LoxP recombination system for cell lineage tracing is a widely used technique. In this chapter, we describe protocols used for inducible Cre/LoxP recombination-mediated lineage tracing of osteoblast progenitors during medaka fin regeneration as well as during the repair of osteoporosis-like bone lesions in the medaka vertebral column. Our approach can be adapted for lineage tracing of other cell populations in the regenerating teleost fin or in other tissues undergoing repair.
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Affiliation(s)
- Wen Hui Tan
- Department of Developmental Genetics, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany.
| | - Christoph Winkler
- Department of Biological Sciences and Centre for Bioimaging Sciences, National University of Singapore, Singapore, Singapore
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16
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Soto AF, Teixeira ÉF, Lamers ML, Mengatto CM. Effects of Hemin Supplementation on Bone Precursor Cells: An Experimental Study. Stem Cell Rev Rep 2024; 20:440-442. [PMID: 37837500 DOI: 10.1007/s12015-023-10634-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/16/2023] [Indexed: 10/16/2023]
Affiliation(s)
- Artur Ferronato Soto
- Health Sciences Center, Federal University of Santa Catarina (UFSC), 88040-900, Florianópolis, SC, Brazil
| | - Érico Fabbro Teixeira
- Faculty of Dentistry, Federal University of Rio Grande do Sul (UFRGS), 90035-003, Porto Alegre, RS, Brazil
| | - Marcelo Lazzaron Lamers
- Institute of Basic Health Sciences, Federal University of Rio Grande do Sul (UFRGS), 90035-003, Porto Alegre, RS, Brazil
| | - Cristiane Machado Mengatto
- Department of Conservative Dentistry, Faculty of Dentistry, Federal University of Rio Grande do Sul (UFRGS), 90035-003, Porto Alegre, RS, Brazil.
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17
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Schlundt C, Saß RA, Bucher CH, Bartosch S, Hauser AE, Volk HD, Duda GN, Schmidt-Bleek K. Complex Spatio-Temporal Interplay of Distinct Immune and Bone Cell Subsets during Bone Fracture Healing. Cells 2023; 13:40. [PMID: 38201244 PMCID: PMC10777943 DOI: 10.3390/cells13010040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 12/15/2023] [Accepted: 12/22/2023] [Indexed: 01/12/2024] Open
Abstract
BACKGROUND The healing of a bone injury is a highly complex process involving a multitude of different tissue and cell types, including immune cells, which play a major role in the initiation and progression of bone regeneration. METHODS We histologically analyzed the spatio-temporal occurrence of cells of the innate immune system (macrophages), the adaptive immune system (B and T lymphocytes), and bone cells (osteoblasts and osteoclasts) in the fracture area of a femoral osteotomy over the healing time. This study was performed in a bone osteotomy gap mouse model. We also investigated two key challenges of successful bone regeneration: hypoxia and revascularization. RESULTS Macrophages were present in and around the fracture gap throughout the entire healing period. The switch from initially pro-inflammatory M1 macrophages to the anti-inflammatory M2 phenotype coincided with the revascularization as well as the appearance of osteoblasts in the fracture area. This indicates that M2 macrophages are necessary for the restoration of vessels and that they also play an orchestrating role in osteoblastogenesis during bone healing. The presence of adaptive immune cells throughout the healing process emphasizes their essential role for regenerative processes that exceeds a mere pathogen defense. B and T cells co-localize consistently with bone cells throughout the healing process, consolidating their crucial role in guiding bone formation. These histological data provide, for the first time, comprehensive information about the complex interrelationships of the cellular network during the entire bone healing process in one standardized set up. With this, an overall picture of the spatio-temporal interplay of cellular key players in a bone healing scenario has been created. CONCLUSIONS A spatio-temporal distribution of immune cells, bone cells, and factors driving bone healing at time points that are decisive for this process-especially during the initial steps of inflammation and revascularization, as well as the soft and hard callus phases-has been visualized. The results show that the bone healing cascade does not consist of five distinct, consecutive phases but is a rather complex interrelated and continuous process of events, especially at the onset of healing.
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Affiliation(s)
- Claudia Schlundt
- Julius Wolff Institut, BIH at Charité—Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany; (C.S.); (R.A.S.); (C.H.B.); (G.N.D.)
- BIH Center for Regenerative Therapies, BIH at Charité—Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany;
| | - Radost A. Saß
- Julius Wolff Institut, BIH at Charité—Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany; (C.S.); (R.A.S.); (C.H.B.); (G.N.D.)
- BIH Center for Regenerative Therapies, BIH at Charité—Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany;
| | - Christian H. Bucher
- Julius Wolff Institut, BIH at Charité—Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany; (C.S.); (R.A.S.); (C.H.B.); (G.N.D.)
- BIH Center for Regenerative Therapies, BIH at Charité—Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany;
| | - Sabine Bartosch
- Berlin School for Regenerative Therapies, Charité—Universitätsmedizin Berlin, Augustenburger Plarz 1, 13353 Berlin, Germany;
| | - Anja E. Hauser
- Rheumatology and Clinical Immunology, Charité—Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany;
- Immune Dynamics, Deutsches Rheuma-Forschungszentrum Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Hans-Dieter Volk
- BIH Center for Regenerative Therapies, BIH at Charité—Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany;
- Institute of Medical Immunology, Charité—Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany
| | - Georg N. Duda
- Julius Wolff Institut, BIH at Charité—Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany; (C.S.); (R.A.S.); (C.H.B.); (G.N.D.)
- BIH Center for Regenerative Therapies, BIH at Charité—Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany;
| | - Katharina Schmidt-Bleek
- Julius Wolff Institut, BIH at Charité—Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany; (C.S.); (R.A.S.); (C.H.B.); (G.N.D.)
- BIH Center for Regenerative Therapies, BIH at Charité—Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany;
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Choi JW, Lim S, Jung SE, Jeong S, Moon H, Song BW, Kim IK, Lee S, Hwang KC, Kim SW. Enhanced Osteocyte Differentiation: Cathepsin D and L Secretion by Human Adipose-Derived Mesenchymal Stem Cells. Cells 2023; 12:2852. [PMID: 38132172 PMCID: PMC10742070 DOI: 10.3390/cells12242852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 12/14/2023] [Accepted: 12/16/2023] [Indexed: 12/23/2023] Open
Abstract
Adipose-derived mesenchymal stem cells (ASCs) have the potential to differentiate into bone, cartilage, fat, and neural cells and promote tissue regeneration and healing. It is known that they can have variable responses to hypoxic conditions. In the present study, we aimed to explore diverse changes in the cells and secretome of ASCs under a hypoxic environment over time and to present the possibility of ASCs as therapeutic agents from a different perspective. The expression differences of proteins between normoxic and hypoxic conditions (6, 12, or 24 h) were specifically investigated in human ASCs using 2-DE combined with MALDI-TOF MS analysis, and secreted proteins in ASC-derived conditioned media (ASC-derived CM) were examined by an adipokine array. In addition, genetic and/or proteomic interactions were assessed using a DAVID and miRNet functional annotation bioinformatics analysis. We found that 64 and 5 proteins were differentially expressed in hypoxic ASCs and in hypoxic ASC-derived CM, respectively. Moreover, 7 proteins among the 64 markedly changed spots in hypoxic ASCs were associated with bone-related diseases. We found that two proteins, cathepsin D (CTSD) and cathepsin L (CTSL), identified through an adipokine array independently exhibited significant efficacy in promoting osteocyte differentiation in bone-marrow-derived mesenchymal stem cells (BM-MSCs). This finding introduces a promising avenue for utilizing hypoxia-preconditioned ASC-derived CM as a potential therapeutic approach for bone-related diseases.
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Affiliation(s)
- Jung-Won Choi
- Medical Science Research Institute, College of Medicine, Catholic Kwandong University, Incheon Metropolitan City 22711, Republic of Korea; (J.-W.C.); (S.E.J.)
| | - Soyeon Lim
- Department of Convergence Science, College of Medicine, Catholic Kwandong University, Incheon Metropolitan City 22711, Republic of Korea; (S.L.); (B.-W.S.); (I.-K.K.); (S.L.); (K.-C.H.)
| | - Seung Eun Jung
- Medical Science Research Institute, College of Medicine, Catholic Kwandong University, Incheon Metropolitan City 22711, Republic of Korea; (J.-W.C.); (S.E.J.)
| | - Seongtae Jeong
- The Interdisciplinary Graduate Program in Integrative Biotechnology, Yonsei University, Seoul 03722, Republic of Korea;
| | - Hanbyeol Moon
- Department of Integrated Omics for Biomedical Sciences, Graduate School, Yonsei University, Seoul 03722, Republic of Korea;
| | - Byeong-Wook Song
- Department of Convergence Science, College of Medicine, Catholic Kwandong University, Incheon Metropolitan City 22711, Republic of Korea; (S.L.); (B.-W.S.); (I.-K.K.); (S.L.); (K.-C.H.)
| | - Il-Kwon Kim
- Department of Convergence Science, College of Medicine, Catholic Kwandong University, Incheon Metropolitan City 22711, Republic of Korea; (S.L.); (B.-W.S.); (I.-K.K.); (S.L.); (K.-C.H.)
| | - Seahyoung Lee
- Department of Convergence Science, College of Medicine, Catholic Kwandong University, Incheon Metropolitan City 22711, Republic of Korea; (S.L.); (B.-W.S.); (I.-K.K.); (S.L.); (K.-C.H.)
| | - Ki-Chul Hwang
- Department of Convergence Science, College of Medicine, Catholic Kwandong University, Incheon Metropolitan City 22711, Republic of Korea; (S.L.); (B.-W.S.); (I.-K.K.); (S.L.); (K.-C.H.)
| | - Sang Woo Kim
- Department of Convergence Science, College of Medicine, Catholic Kwandong University, Incheon Metropolitan City 22711, Republic of Korea; (S.L.); (B.-W.S.); (I.-K.K.); (S.L.); (K.-C.H.)
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Danyukova T, Alimy AR, Velho RV, Yorgan TA, Di Lorenzo G, von Kroge S, Tidow H, Wiegert JS, Hermans-Borgmeyer I, Schinke T, Rolvien T, Pohl S. Mice heterozygous for an osteogenesis imperfecta-linked MBTPS2 variant display a compromised subchondral osteocyte lacunocanalicular network associated with abnormal articular cartilage. Bone 2023; 177:116927. [PMID: 37797712 DOI: 10.1016/j.bone.2023.116927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 09/20/2023] [Accepted: 10/02/2023] [Indexed: 10/07/2023]
Abstract
Missense variants in the MBTPS2 gene, located on the X chromosome, have been associated with an X-linked recessive form of osteogenesis imperfecta (X-OI), an inherited bone dysplasia characterized by multiple and recurrent bone fractures, short stature, and various skeletal deformities in affected individuals. The role of site-2 protease, encoded by MBTPS2, and the molecular pathomechanism underlying the disease are to date elusive. This study is the first to report on the generation of two Mbtps2 mouse models, a knock-in mouse carrying one of the disease-causative MBTPS2 variants (N455S) and a Mbtps2 knock-out (ko) mouse. Because both loss-of-function variants lead to embryonic lethality in hemizygous male mutant mice, we performed a comprehensive skeletal analysis of heterozygous Mbtps2+/N455S and Mbtps2+/ko female mice. Both models displayed osteochondral abnormalities such as thinned subchondral bone, altered subchondral osteocyte interconnectivity as well as thickened articular cartilage with chondrocyte clustering, altogether resembling an early osteoarthritis (OA) phenotype. However, distant from the joints, no alterations in the bone mass and turnover could be detected in either of the mutant mice. Based on our findings we conclude that MBTPS2 haploinsufficiency results in early OA-like alterations in the articular cartilage and underlying subchondral bone, which likely precede the development of typical OI phenotype in bone. Our study provides first evidence for a potential role of site-2 protease for maintaining homeostasis of both bone and cartilage.
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Affiliation(s)
- Tatyana Danyukova
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany.
| | - Assil-Ramin Alimy
- Department of Trauma and Orthopedic Surgery, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany.
| | - Renata Voltolini Velho
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany.
| | - Timur A Yorgan
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany.
| | - Giorgia Di Lorenzo
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany.
| | - Simon von Kroge
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany; Department of Trauma and Orthopedic Surgery, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany.
| | - Henning Tidow
- The Hamburg Advanced Research Center for Bioorganic Chemistry (HARBOR), Department of Chemistry, Institute for Biochemistry and Molecular Biology, University of Hamburg, 20146 Hamburg, Germany.
| | - J Simon Wiegert
- Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany.
| | - Irm Hermans-Borgmeyer
- Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Thorsten Schinke
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany.
| | - Tim Rolvien
- Department of Trauma and Orthopedic Surgery, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany.
| | - Sandra Pohl
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany.
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20
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Chen K, Chen H, Deng L, Yang K, Qi J. IDG-SW3 Cell Culture in a Three-Dimensional Extracellular Matrix. J Vis Exp 2023. [PMID: 38009754 DOI: 10.3791/64507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2023] Open
Abstract
Osteocytes are considered to be nonproliferative cells that are terminally differentiated from osteoblasts. Osteoblasts embedded in the bone extracellular matrix (osteoid) express the Pdpn gene to form cellular dendrites and transform into preosteocytes. Later, preosteocytes express the Dmp1 gene to promote matrix mineralization and thereby transform into mature osteocytes.This process is called osteocytogenesis. IDG-SW3 is a well-known cell line for in vitro studies of osteocytogenesis. Many previous methods have used collagen I as the main or the only component of the culturing matrix. However, in addition to collagen I, the osteoid also contains a ground substance, which is an important component in promoting cellular growth, adhesion, and migration. In addition, the matrix substance is transparent, which increases the transparency of the collagen I-formed gel and, thus, aids the exploration of dendrite formation through imaging techniques. Thus, this paper details a protocol to establish a 3D gel using an extracellular matrix along with collagen I for IDG-SW3 survival. In this work, dendrite formation and gene expression were analyzed during osteocytogenesis. After 7 days of osteogenic culture, an extensive dendrite network was clearly observed under a fluorescence confocal microscope. Real-time PCR showed that the mRNA levels of Pdpn and Dmp1 continually increased for 3 weeks. At week 4, the stereomicroscope revealed an opaque gel filled with mineral particles, consistent with the X-ray fluorescence (XRF) assay. These results indicate that this culture matrix successfully facilitates the transition from osteoblasts to mature osteocytes.
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Affiliation(s)
- Kaizhe Chen
- Department of Orthopedics, Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases, Shanghai Institute of Traumatology and Orthopaedics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine
| | - Haoyi Chen
- Department of Orthopedics, Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases, Shanghai Institute of Traumatology and Orthopaedics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine
| | - Lianfu Deng
- Department of Orthopedics, Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases, Shanghai Institute of Traumatology and Orthopaedics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine;
| | - Kai Yang
- Department of Orthopedics, Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases, Shanghai Institute of Traumatology and Orthopaedics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine;
| | - Jin Qi
- Department of Orthopedics, Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases, Shanghai Institute of Traumatology and Orthopaedics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine;
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21
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Yan M, Zhang Y, Niu W, Liu K, Xue L, Zhou K. Reactive oxygen species-mediated endoplasmic reticulum stress contributes to osteocyte death induced by orthodontic compressive force. Microsc Res Tech 2023; 86:1529-1541. [PMID: 37382312 DOI: 10.1002/jemt.24382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Revised: 05/22/2023] [Accepted: 06/18/2023] [Indexed: 06/30/2023]
Abstract
During orthodontic tooth movement (OTM), osteocytes, the most mechanosensitive cells in alveolar bone, suffer the heavy orthodontic force and initiate alveolar bone resorption on the compression side. However, the inherent mechanisms of compressive force-induced osteocyte death are not fully understood. In this study, we established an OTM model on Sprague-Dawley rats by inserting coil springs to investigate osteocyte damage on the compression side of alveolar bone. We then applied compressive force on the MLO-Y4 osteocyte-like cell line in vitro to explore whether the reactive oxygen species (ROS)-mediated endoplasmic reticulum stress (ERS) pathway is involved in compressive force-induced osteocyte death. We found that the orthodontic force caused apparent alveolar bone loss, osteocyte death, and elevated serum sclerostin and receptor activator of NF-κB ligand (RANKL) levels in rats. In vitro, compressive force inhibited cell viability but increased the LDH leakage and loss of mitochondrial membrane potential in MLO-Y4 cells. Simultaneously, it activated protein kinase RNA-like endoplasmic reticulum kinase (PERK), eukaryotic translation initiation factor 2 (eIF2α), and their downstream pro-apoptotic ERS signaling proteins and caused significant osteocyte apoptosis, which can be blocked by ERS inhibitor salubrinal. Moreover, the compressive force elevated intracellular ROS levels, while the ROS scavenger N-acetyl-L-cysteine (NAC) alleviated ERS and apoptosis in loaded osteocytes. These results suggest that the orthodontic compressive force induced osteocyte apoptosis via the ROS-mediated ERS pathway. This study first proposes the ERS pathway as a new potential pathway for regulating the rate of OTM based on osteocyte death. RESEARCH HIGHLIGHTS: The orthodontic force increases osteocyte death in rat alveolar bone. The compressive force causes osteocyte apoptosis by the endoplasmic reticulum stress (ERS) pathway in vitro. The ROS scavenger NAC blocked compressive force-induced ERS and osteocyte apoptosis.
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Affiliation(s)
- Ming Yan
- School of Automation, Hangzhou Dianzi University, Hangzhou, People's Republic of China
| | - Yun Zhang
- College of Medicine, Shaoxing University, Shaoxing, People's Republic of China
| | - Wanting Niu
- Department of STEM, Regis College, Weston, Massachusetts, USA
| | - Kezhou Liu
- School of Automation, Hangzhou Dianzi University, Hangzhou, People's Republic of China
| | - Lingyun Xue
- School of Automation, Hangzhou Dianzi University, Hangzhou, People's Republic of China
| | - Kexin Zhou
- West China School of Medicine, Sichuan University, Chengdu, People's Republic of China
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22
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Sano H, Whitmarsh T, Skingle L, Shimakura T, Yamamoto N, Compston JE, Takahashi HE, Poole KES. Buds of new bone formation within the Femoral Head of Hip Fracture Patients Coincide with Zones of Low Osteocyte Sclerostin. J Bone Miner Res 2023; 38:1603-1611. [PMID: 37548352 DOI: 10.1002/jbmr.4898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Revised: 06/19/2023] [Accepted: 08/04/2023] [Indexed: 08/08/2023]
Abstract
Romosozumab treatment reduces the rate of hip fractures and increases hip bone density, increasing bone formation by inhibiting sclerostin protein. We studied the normal pattern of bone formation and osteocyte expression in the human proximal femur because it is relevant to both antisclerostin treatment effects and fracture. Having visualized and quantified buds of new bone formation in trabeculae, we hypothesized that they would coincide with areas of (a) higher mechanical stress and (b) low sclerostin expression by osteocytes. In patients with hip fracture, we visualized each bud of active modeling-based formation (forming minimodeling structure [FMiS]) in trabecular cores taken from different parts of the femoral head. Trabecular bone structure was also measured with high-resolution imaging. More buds of new bone formation (by volume) were present in the higher stress superomedial zone (FMiS density, N.FMiS/T.Ar) than lower stress superolateral (p < 0.05), and inferomedial (p < 0.001) regions. There were fewer sclerostin expressing osteocytes close to or within FMiS. FMiS density correlated with greater amount, thickness, number, and connectivity of trabeculae (bone volume BV/TV, r = 0.65, p < 0.0001; bone surface BS/TV, r = 0.47, p < 0.01; trabecular thickness Tb.Th, r = 0.55, p < 0.001; trabecular number Tb.N, r = 0.47, p < 0.01; and connectivity density Conn.D, r = 0.40, p < 0.05) and lower trabecular separation (Tb.Sp, r = -0.56, p < 0.001). These results demonstrate modeling-based bone formation in femoral trabeculae from patients with hip fracture as a potential therapeutic target to enhance bone structure. © 2023 American Society for Bone and Mineral Research (ASBMR).
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Affiliation(s)
- Hiroshige Sano
- Department of Medicine, University of Cambridge, Cambridge, UK
- Niigata Bone Science Institute, Niigata, Japan
- Uchino Orthopedic Clinic, Niigata, Japan
| | | | - Linda Skingle
- Department of Medicine, University of Cambridge, Cambridge, UK
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23
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Ahmed F, Minamizaki T, Aubin JE, Damayanti MA, Yoshiko Y. Large scale analysis of osteocyte lacunae in klotho hypomorphic mice using high-resolution micro-computed tomography. Ann Anat 2023; 250:152142. [PMID: 37572763 DOI: 10.1016/j.aanat.2023.152142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2023] [Revised: 07/14/2023] [Accepted: 07/26/2023] [Indexed: 08/14/2023]
Abstract
BACKGROUND Osteocytes are the most abundant cell type in adult bone, and the morphological characteristics of osteocytes and their lacunae appear to influence bone mass and fragility. Although conventional computed tomography (CT) has contributed greatly to advances in bone morphometry, capturing details of the entire hierarchical assembly, e.g., osteocyte lacuna parameters, has been limited by the analytical performance of CT (> 1 µm resolution). METHODS We used high-resolution (700 nm) micro-CT to evaluate and compare the osteocyte lacuna parameters over a large scale, i.e., in a maximum of about 45,700 lacunae (average), in tibial metaphyseal cortical bones of wild-type (WT) and αKlotho-hypomorphic (kl/kl) mice, the latter a model that exhibits osteopenia and aberrant osteocytes. RESULTS Of osteocyte lacuna parameters, lacunar surface per lacunar volume were significantly lower and lacuna diameter were significantly larger in kl/kl mice compared to WT mice. By analysis of individual osteocyte lacunae, we found that lacunar sphericity in kl/kl mice was higher than that in WT mice, and the diameters in the major and the minor axes were respectively lower and higher in kl/kl mice, especially at the proximal site of the region of interest. CONCLUSION We successfully assessed osteocyte lacuna parameters on the largest scale in mice reported to date and found that the shape of osteocyte lacunae of kl/kl mice are significantly different from those of WT mice. Although the mechanisms underlying the lacunar shape differences observed are not yet clear, changes in lacunar geometry are known to affect the transitions of strains to the osteocyte microenvironment and likely local osteocyte response(s). Thus, the fact that the differences are limited to the mesial region near the primary spongiosa suggests the likelihood of site-specific anomalies in mechanosensitive effects in kl/kl osteocytes with consequent site-specific effects bone metabolism and function.
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Affiliation(s)
- Faisal Ahmed
- Department of Calcified Tissue Biology, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
| | - Tomoko Minamizaki
- Department of Calcified Tissue Biology, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
| | - Jane E Aubin
- Department of Molecular Genetics, University of Toronto, Toronto, Canada
| | - Merry Annisa Damayanti
- Department of Calcified Tissue Biology, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan; Department of Dentomaxillofacial Radiology, Faculty of Dentistry, Padjadjaran University, Bandung, Indonesia
| | - Yuji Yoshiko
- Department of Calcified Tissue Biology, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan.
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24
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Liu Y, Pu X, Duan M, Chen C, Zhao Y, Zhang D, Xie J. Biomimetic Fibers Derived from an Equidistant Micropillar Platform Dictate Osteocyte Fate via Mechanoreception. Nano Lett 2023; 23:7950-7960. [PMID: 37418659 DOI: 10.1021/acs.nanolett.3c01739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/09/2023]
Abstract
It is a big challenge to design a biomimetic physical microenvironment with greater similarity to in vivo tissue to observe real cell behaviors. We established a novel cell culture platform based on patterned equidistant micropillars with stiff and soft stiffnesses to mimic the changes that happened in the transition from normal to osteoporotic disease. We first demonstrated that the soft micropillar substrate decreased osteocyte synaptogenesis through synaptogyrin 1 and that this decrease was accompanied by impairment of cell mechanoperception and a decrease in cellular cytoskeletal rearrangement. We then found that the soft equidistant micropillar substrate reduced the osteocyte synaptogenesis mainly via the inactivation of Erk/MAPK signaling. We finally found that soft micropillar substrate-mediated synaptogenesis impacted the cell-to-cell communication and matrix mineralization of osteocytes. Taken together, this study provides evidence of cellular mechanical responses that are much more similar to those of real osteocytes at the bone tissue level.
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Affiliation(s)
- Yang Liu
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610044, China
| | - Xiaohua Pu
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610044, China
| | - Mengmeng Duan
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610044, China
| | - Cheng Chen
- College of Medical Informatics, Chongqing Medical University, Chongqing 400016, China
| | - Yanfang Zhao
- Department of Pediatric Dentistry, School of Dentistry, The University of Alabama at Birmingham, 1919 7th Ave. S, Birmingham, Alabama 35233, United States
| | - Demao Zhang
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610044, China
- Institute of Biomedical Engineering, West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu 610041, China
| | - Jing Xie
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610044, China
- National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610044, China
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25
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Arai M, Ochi H, Sunamura S, Ito N, Nangaku M, Takeda S, Sato S. A Novel Long Noncoding RNA in Osteocytes Regulates Bone Formation through the Wnt/β-Catenin Signaling Pathway. Int J Mol Sci 2023; 24:13633. [PMID: 37686441 PMCID: PMC10488071 DOI: 10.3390/ijms241713633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2023] [Revised: 08/30/2023] [Accepted: 08/31/2023] [Indexed: 09/10/2023] Open
Abstract
The vast majority of transcribed RNAs are noncoding RNAs. Among noncoding RNAs, long noncoding RNAs (lncRNAs), which contain hundreds to thousands of bases, have received attention in many fields. The vast majority of the constituent cells in bone tissue are osteocytes, but their regulatory mechanisms are incompletely understood. Considering the wide range of potential contributions of lncRNAs to physiological processes and pathological conditions, we hypothesized that lncRNAs in osteocytes, which have not been reported, could be involved in bone metabolism. Here, we first isolated osteocytes from femurs of mice with osteocyte-specific GFP expression. Then, through RNA-sequencing, we identified osteocyte-specific lncRNAs and focused on a novel lncRNA, 9530026P05Rik (lncRNA953Rik), which strongly suppressed osteogenic differentiation. In the IDG-SW3 osteocyte line with lncRNA953Rik overexpression, the expression of Osterix and its downstream genes was reduced. RNA pull-down and subsequent LC-MS/MS analysis revealed that lncRNA953Rik bound the nuclear protein CCAR2. We demonstrated that CCAR2 promoted Wnt/β-catenin signaling and that lncRNA953Rik inhibited this pathway. lncRNA953Rik sequestered CCAR2 from HDAC1, leading to deacetylation of H3K27 in the Osterix promoter and consequent transcriptional downregulation of Osterix. This research is the first to clarify the role of a lncRNA in osteocytes. Our findings can pave the way for novel therapeutic options targeting lncRNAs in osteocytes to treat bone metabolic diseases such as osteoporosis.
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Affiliation(s)
- Makoto Arai
- Division of Nephrology and Endocrinology, The University of Tokyo Hospital, Tokyo 113-8655, Japan
| | - Hiroki Ochi
- Department of Rehabilitation for Motor Functions, Research Institute, National Rehabilitation Center for Persons with Disabilities, Tokorozawa 359-8555, Japan
| | - Satoko Sunamura
- Department of Orthopaedic Surgery, Graduate School, Tokyo Medical and Dental University (TMDU), Tokyo 113-8519, Japan
| | - Nobuaki Ito
- Division of Nephrology and Endocrinology, The University of Tokyo Hospital, Tokyo 113-8655, Japan
- Osteoporosis Center, The University of Tokyo Hospital, Tokyo 113-8655, Japan
| | - Masaomi Nangaku
- Division of Nephrology and Endocrinology, The University of Tokyo Hospital, Tokyo 113-8655, Japan
| | - Shu Takeda
- Division of Endocrinology, Toranomon Hospital Endocrine Center, Tokyo 105-8470, Japan
| | - Shingo Sato
- Center for Innovative Cancer Treatment, Tokyo Medical and Dental University (TMDU), Tokyo 113-8519, Japan
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26
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Yang P, Xu B, Zhu R, Zhang T, Wang Z, Lin Q, Yan M, Yu Z, Mao H, Zhang Y. ROS-mediated mitophagy and necroptosis regulate osteocytes death caused by TCP particles in MLO-Y4 cells. Toxicology 2023; 496:153627. [PMID: 37678662 DOI: 10.1016/j.tox.2023.153627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Revised: 08/30/2023] [Accepted: 09/03/2023] [Indexed: 09/09/2023]
Abstract
Our previous data have revealed TCP particles caused cell death of osteocytes, comprising over 95 % of all bone cells, which contribute to periprosthetic osteolysis, joint loosening and implant failure, but its mechanisms are not fully understood. Here, we reported that TCP particles inhibited cell viability of osteocytes MLO-Y4, and caused cell death. TCP particles caused mitochondrial impairment and increased expressions of LC-3 II, Parkin and PINK 1, accompanied by the elevation of autophagy flux and intracellular acidic components, the accumulation of LC-3II, PINK1 and Parkin in damaged mitochondria, and p62 reduction. The increased LC-3II expression and cell death extent were significantly enhanced by the autophagy inhibitor Baf A1, compared with Baf A1 (or TCP particles) alone, indicating that TCP particles increase autophagic flux and lead to cell even death of MLO-Y4 cells, closely associated with mitophagy. Furthermore, TCP particles induced propidium iodide (PI) uptake and the phosphorylation of RIP1, RIP3 and MLKL, thereby increasing necroptosis in MLO-Y4 cells. The pro-necroptotic effect was alleviated by the RIP1 inhibitor Nec-1 or the MLKL inhibitor NSA. Additionally, TCP particles promoted the production of intracellular reactive oxygen species (ROS) and mitochondrial ROS (mtROS), and increased TXNIP expression, but decreased protein levels of TRX1, Nrf2, HO-1 and NQO1, leading to oxidative stress. The ROS scavenger NAC remarkably reversed mitophagy and necroptosis caused by TCP particles, suggesting that ROS is responsible for mitophagy and necroptosis. Collectively, ROS-mediated mitophagy and necroptosis regulate osteocytes death caused by TCP particles in MLO-Y4 cells, which enhances osteoclastogenesis and periprosthetic osteolysis.
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Affiliation(s)
- Pei Yang
- College of Medicine, Shaoxing University, Huancheng West Road 508, Shaoxing 312000, PR China
| | - Bingbing Xu
- College of Medicine, Shaoxing University, Huancheng West Road 508, Shaoxing 312000, PR China
| | - Ruirong Zhu
- College of Medicine, Shaoxing University, Huancheng West Road 508, Shaoxing 312000, PR China
| | - Tao Zhang
- College of Medicine, Shaoxing University, Huancheng West Road 508, Shaoxing 312000, PR China
| | - Zihan Wang
- College of Medicine, Shaoxing University, Huancheng West Road 508, Shaoxing 312000, PR China
| | - Qiao Lin
- College of Medicine, Shaoxing University, Huancheng West Road 508, Shaoxing 312000, PR China
| | - Ming Yan
- School of Automation, Hangzhou Dianzi University, Xiasha Higher Education Zone, 1158 2nd Avenue, Hangzhou 310018, PR China
| | - Zhangsen Yu
- College of Medicine, Shaoxing University, Huancheng West Road 508, Shaoxing 312000, PR China
| | - Hongjiao Mao
- College of Medicine, Shaoxing University, Huancheng West Road 508, Shaoxing 312000, PR China
| | - Yun Zhang
- College of Medicine, Shaoxing University, Huancheng West Road 508, Shaoxing 312000, PR China.
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27
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Lipreri MV, Di Pompo G, Boanini E, Graziani G, Sassoni E, Baldini N, Avnet S. Bone on-a-chip: a 3D dendritic network in a screening platform for osteocyte-targeted drugs. Biofabrication 2023; 15:045019. [PMID: 37552982 DOI: 10.1088/1758-5090/acee23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 08/08/2023] [Indexed: 08/10/2023]
Abstract
Age-related musculoskeletal disorders, including osteoporosis, are frequent and associated with long lasting morbidity, in turn significantly impacting on healthcare system sustainability. There is therefore a compelling need to develop reliable preclinical models of disease and drug screening to validate novel drugs possibly on a personalized basis, without the need ofin vivoassay. In the context of bone tissue, although the osteocyte (Oc) network is a well-recognized therapeutic target, currentin vitropreclinical models are unable to mimic its physiologically relevant and highly complex structure. To this purpose, several features are needed, including an osteomimetic extracellular matrix, dynamic perfusion, and mechanical cues (e.g. shear stress) combined with a three-dimensional (3D) culture of Oc. Here we describe, for the first time, a high throughput microfluidic platform based on 96-miniaturized chips for large-scale preclinical evaluation to predict drug efficacy. We bioengineered a commercial microfluidic device that allows real-time visualization and equipped with multi-chips by the development and injection of a highly stiff bone-like 3D matrix, made of a blend of collagen-enriched natural hydrogels loaded with hydroxyapatite nanocrystals. The microchannel, filled with the ostemimetic matrix and Oc, is subjected to passive perfusion and shear stress. We used scanning electron microscopy for preliminary material characterization. Confocal microscopy and fluorescent microbeads were used after material injection into the microchannels to detect volume changes and the distribution of cell-sized objects within the hydrogel. The formation of a 3D dendritic network of Oc was monitored by measuring cell viability, evaluating phenotyping markers (connexin43, integrin alpha V/CD51, sclerostin), quantification of dendrites, and responsiveness to an anabolic drug. The platform is expected to accelerate the development of new drug aimed at modulating the survival and function of osteocytes.
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Affiliation(s)
| | - Gemma Di Pompo
- Biomedical Science, Technologies, and Nanobiotecnologiy Lab, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy
| | - Elisa Boanini
- Department of Chemistry 'Giacomo Ciamician', University of Bologna, Bologna, Italy
| | - Gabriela Graziani
- Biomedical Science, Technologies, and Nanobiotecnologiy Lab, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy
| | - Enrico Sassoni
- Department of Civil, Chemical, Environmental and Materials Engineering, University of Bologna, Bologna, Italy
| | - Nicola Baldini
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
- Biomedical Science, Technologies, and Nanobiotecnologiy Lab, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy
| | - Sofia Avnet
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
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28
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Ji C, Zhang L, Wang Y, Lin B, Bai X, Yun S, He B. The influence of different shaped osteocyte lacunae on microcrack initiation and propagation. Clin Biomech (Bristol, Avon) 2023; 108:106072. [PMID: 37611387 DOI: 10.1016/j.clinbiomech.2023.106072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 08/12/2023] [Accepted: 08/16/2023] [Indexed: 08/25/2023]
Abstract
BACKGROUND The morphology of osteocyte lacunae varies in bones of different ages and bone pathologies. Osteocyte lacunae can cause stress concentration and initiate microcracks. However, the influence of changes in osteocyte lacunar shape on microcrack is unknown. Therefore, the aim of this study was to determine the effects of osteocyte lacunae with different shapes on microcrack initiation and propagation. METHODS Osteon models containing osteocyte lacunae with different shapes were established. The progressive damage analysis method, based on computer simulations, was used to study the evolution of microdamage within the osteon, including the processes of intralaminar and interlaminar microdamage. FINDINGS Models with larger DoE values can effectively delay or prevent the formation of linear microcracks, which ensures high fracture toughness of cortical bone. It is subjected to stronger mechanical stimulation, making it more sensitive to loads. Models with smaller DoE values increase the load threshold for microdamage generation and reduces its impact on bone mechanical performance, making it less susceptible to microdamage than models with larger DoE values. INTERPRETATION These findings enhance the limited knowledge of the influence of the lacunar shape on microdamage and contribute to a better understanding of bone biomechanics.
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Affiliation(s)
- Chunhui Ji
- School of Mechanical Engineering, Tianjin University, Tianjin 300072, PR China
| | - Liang Zhang
- School of Mechanical Engineering, Tianjin University, Tianjin 300072, PR China
| | - Yan Wang
- Tianjin Hospital, Tianjin University, Tianjin 300072, PR China
| | - Bin Lin
- School of Mechanical Engineering, Tianjin University, Tianjin 300072, PR China.
| | - Xinlei Bai
- School of Mechanical Engineering, Tianjin University, Tianjin 300072, PR China
| | - Shiyue Yun
- School of Mechanical Engineering, Tianjin University, Tianjin 300072, PR China
| | - Bingnan He
- School of Mechanical Engineering, Tianjin University, Tianjin 300072, PR China
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Guo Q, Chen N, Qian C, Qi C, Noller K, Wan M, Liu X, Zhang W, Cahan P, Cao X. Sympathetic Innervation Regulates Osteocyte-Mediated Cortical Bone Resorption during Lactation. Adv Sci (Weinh) 2023; 10:e2207602. [PMID: 37186379 PMCID: PMC10288263 DOI: 10.1002/advs.202207602] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 02/13/2023] [Indexed: 05/17/2023]
Abstract
Bone undergoes constant remodeling by osteoclast bone resorption coupled with osteoblast bone formation at the bone surface. A third major cell type in the bone is osteocytes, which are embedded in the matrix, are well-connected to the lacunar network, and are believed to act as mechanical sensors. Here, it is reported that sympathetic innervation directly regulates lacunar osteocyte-mediated bone resorption inside cortical bone. It is found that sympathetic activity is elevated in different mouse models of bone loss, including lactation, ovariectomy, and glucocorticoid treatment. Further, during lactation elevated sympathetic outflow induces netrin-1 expression by osteocytes to further promote sympathetic nerve sprouting in the cortical bone endosteum in a feed-forward loop. Depletion of tyrosine hydroxylase-positive (TH+ ) sympathetic nerves ameliorated osteocyte-mediated perilacunar bone resorption in lactating mice. Moreover, norepinephrine activates β-adrenergic receptor 2 (Adrb2) signaling to promote secretion of extracellular vesicles (EVs) containing bone-degrading enzymes for perilacunar bone resorption and inhibit osteoblast differentiation. Importantly, osteocyte-specific deletion of Adrb2 or treatment with a β-blocker results in lower bone resorption in lactating mice. Together, these findings show that the sympathetic nervous system promotes osteocyte-driven bone loss during lactation, likely as an adaptive response to the increased energy and mineral demands of the nursing mother.
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Affiliation(s)
- Qiaoyue Guo
- Department of Orthopedic SurgeryJohns Hopkins University School of MedicineBaltimoreMD21205USA
| | - Ningrong Chen
- Department of Orthopedic SurgeryJohns Hopkins University School of MedicineBaltimoreMD21205USA
| | - Cheng Qian
- Department of Orthopedic SurgeryJohns Hopkins University School of MedicineBaltimoreMD21205USA
| | - Cheng Qi
- Department of Orthopedic SurgeryJohns Hopkins University School of MedicineBaltimoreMD21205USA
- Department of Biomedical EngineeringJohns Hopkins University School of MedicineBaltimoreMD21205USA
| | - Kathleen Noller
- Department of Biomedical EngineeringJohns Hopkins University School of MedicineBaltimoreMD21205USA
| | - Mei Wan
- Department of Orthopedic SurgeryJohns Hopkins University School of MedicineBaltimoreMD21205USA
| | - Xiaonan Liu
- Department of Orthopedic SurgeryJohns Hopkins University School of MedicineBaltimoreMD21205USA
| | - Weixin Zhang
- Department of Orthopedic SurgeryJohns Hopkins University School of MedicineBaltimoreMD21205USA
| | - Patrick Cahan
- Department of Biomedical EngineeringJohns Hopkins University School of MedicineBaltimoreMD21205USA
| | - Xu Cao
- Department of Orthopedic SurgeryJohns Hopkins University School of MedicineBaltimoreMD21205USA
- Department of Biomedical EngineeringJohns Hopkins University School of MedicineBaltimoreMD21205USA
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30
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Dragoun Kolibová S, Wölfel EM, Hemmatian H, Milovanovic P, Mushumba H, Wulff B, Neidhardt M, Püschel K, Failla AV, Vlug A, Schlaefer A, Ondruschka B, Amling M, Hofbauer LC, Rauner M, Busse B, Jähn-Rickert K. Osteocyte apoptosis and cellular micropetrosis signify skeletal aging in type 1 diabetes. Acta Biomater 2023; 162:254-265. [PMID: 36878337 DOI: 10.1016/j.actbio.2023.02.037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 02/03/2023] [Accepted: 02/27/2023] [Indexed: 03/07/2023]
Abstract
Bone fragility is a profound complication of type 1 diabetes mellitus (T1DM), increasing patient morbidity. Within the mineralized bone matrix, osteocytes build a mechanosensitive network that orchestrates bone remodeling; thus, osteocyte viability is crucial for maintaining bone homeostasis. In human cortical bone specimens from individuals with T1DM, we found signs of accelerated osteocyte apoptosis and local mineralization of osteocyte lacunae (micropetrosis) compared with samples from age-matched controls. Such morphological changes were seen in the relatively young osteonal bone matrix on the periosteal side, and micropetrosis coincided with microdamage accumulation, implying that T1DM drives local skeletal aging and thereby impairs the biomechanical competence of the bone tissue. The consequent dysfunction of the osteocyte network hampers bone remodeling and decreases bone repair mechanisms, potentially contributing to the enhanced fracture risk seen in individuals with T1DM. STATEMENT OF SIGNIFICANCE: Type 1 diabetes mellitus (T1DM) is a chronic autoimmune disease that causes hyperglycemia. Increased bone fragility is one of the complications associated with T1DM. Our latest study on T1DM-affected human cortical bone identified the viability of osteocytes, the primary bone cells, as a potentially critical factor in T1DM-bone disease. We linked T1DM with increased osteocyte apoptosis and local accumulation of mineralized lacunar spaces and microdamage. Such structural changes in bone tissue suggest that T1DM speeds up the adverse effects of aging, leading to the premature death of osteocytes and potentially contributing to diabetes-related bone fragility.
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Affiliation(s)
- Sofie Dragoun Kolibová
- Department of Osteology and Biomechanics, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Eva Maria Wölfel
- Department of Osteology and Biomechanics, University Medical Center Hamburg Eppendorf, Hamburg, Germany; Interdisciplinary Competence Center for Interface Research, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Haniyeh Hemmatian
- Department of Osteology and Biomechanics, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Petar Milovanovic
- Department of Osteology and Biomechanics, University Medical Center Hamburg Eppendorf, Hamburg, Germany; University of Belgrade, Faculty of Medicine, Center of Bone Biology, Institute of Anatomy, Belgrade, Serbia
| | - Herbert Mushumba
- University Medical Center Hamburg Eppendorf, Institute of Legal Medicine, Hamburg, Germany
| | - Birgit Wulff
- University Medical Center Hamburg Eppendorf, Institute of Legal Medicine, Hamburg, Germany
| | - Maximilian Neidhardt
- Institute of Medical Technology and Intelligent Systems, Hamburg University of Technology, Am-Schwarzenberg-Campus 3, Hamburg 21073, Germany; Interdisciplinary Competence Center for Interface Research, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Klaus Püschel
- University Medical Center Hamburg Eppendorf, Institute of Legal Medicine, Hamburg, Germany
| | - Antonio Virgilio Failla
- University Medical Center Hamburg Eppendorf, UKE microscopy Imaging facility, Hamburg, Germany
| | - Annegreet Vlug
- Leiden University Medical Center (LUMC), Centre for Bone Quality, Leiden, the Netherlands
| | - Alexander Schlaefer
- Institute of Medical Technology and Intelligent Systems, Hamburg University of Technology, Am-Schwarzenberg-Campus 3, Hamburg 21073, Germany; Interdisciplinary Competence Center for Interface Research, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Benjamin Ondruschka
- University Medical Center Hamburg Eppendorf, Institute of Legal Medicine, Hamburg, Germany
| | - Michael Amling
- Department of Osteology and Biomechanics, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Lorenz C Hofbauer
- Division of Endocrinology, Department of Medicine III, Technische Universität Dresden Medical Center, Diabetes, and Metabolic Bone Diseases, Dresden, Germany
| | - Martina Rauner
- Division of Endocrinology, Department of Medicine III, Technische Universität Dresden Medical Center, Diabetes, and Metabolic Bone Diseases, Dresden, Germany
| | - Björn Busse
- Department of Osteology and Biomechanics, University Medical Center Hamburg Eppendorf, Hamburg, Germany; Interdisciplinary Competence Center for Interface Research, University Medical Center Hamburg Eppendorf, Hamburg, Germany.
| | - Katharina Jähn-Rickert
- Department of Osteology and Biomechanics, University Medical Center Hamburg Eppendorf, Hamburg, Germany; Mildred Scheel Cancer Career Center Hamburg, University Cancer Center Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg 20251, Germany
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Lewis KJ, Boorman-Padgett JF, Castaneda M, Spray DC, Thi MM, Schaffler MB. A Fluorescent Intravital Imaging Approach to Study Load-Induced Calcium Signaling Dynamics in Mouse Osteocytes. J Vis Exp 2023. [PMID: 36912542 DOI: 10.3791/64366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/14/2023] Open
Abstract
Bone tissue is exquisitely sensitive to differences in mechanical load magnitude. Osteocytes, dendritic cells that form a syncytium throughout the bone, are responsible for the mechanosensory function of bone tissue. Studies employing histology, mathematical modeling, cell culture, and ex vivo bone organ cultures have greatly advanced the understanding of osteocyte mechanobiology. However, the fundamental question of how osteocytes respond to and encode mechanical information at the molecular level in vivo is not well understood. Intracellular calcium concentration fluctuations in osteocytes offer a useful target for learning more about acute bone mechanotransduction mechanisms. Here, we report a method for studying osteocyte mechanobiology in vivo, combining a mouse strain with a fluorescently genetically encoded calcium indicator expressed in osteocytes with an in vivo loading and imaging system to directly detect osteocyte calcium levels during loading. This is achieved with a three-point bending device that can deliver well-defined mechanical loads to the third metatarsal of living mice while simultaneously monitoring fluorescently indicated calcium responses of osteocytes using two-photon microscopy. This technique allows for direct in vivo observation of osteocyte calcium signaling events in response to whole bone loading and is useful in the endeavor to reveal mechanisms in osteocyte mechanobiology.
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Affiliation(s)
- Karl J Lewis
- Meinig School of Biomedical Engineering, Cornell University;
| | | | - Macy Castaneda
- Sibley School of Mechanical and Aerospace Engineering, Cornell University
| | - David C Spray
- Department of Neuroscience, Albert Einstein College of Medicine
| | - Mia M Thi
- Department of Orthopaedic Surgery, Albert Einstein College of Medicine; Department of Molecular Pharmacology, Albert Einstein College of Medicine
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Nishida T, Kubota S, Takigawa M. Novel Cell Biological Assays for Measuring Bone Remodeling Activities of CCN Proteins. Methods Mol Biol 2023; 2582:255-268. [PMID: 36370355 DOI: 10.1007/978-1-0716-2744-0_17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Although two-dimensional (2D) cultures from bone lineage cells are often used, it is well-known that this culture system is completely different from the in vivo bone matrix environment. In this paper, we describe a 3D culture method using both the mouse osteocytic cell line, MLO-Y4, and an osteocyte-enriched population of the cells isolated from mice. These cells are embedded in collagen gel with recombinant cellular communication network (CCN) factor proteins; then, osteoblasts or osteoclasts are inoculated and cultured on the collagen gel. Because this method mimics the in vitro bone matrix environment, it is useful for understanding the detailed mechanism of actions of CCN proteins in the bone matrix.
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Affiliation(s)
- Takashi Nishida
- Department of Biochemistry and Molecular Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.
- Advanced Research Center for Oral and Craniofacial Sciences, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.
| | - Satoshi Kubota
- Department of Biochemistry and Molecular Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Masaharu Takigawa
- Advanced Research Center for Oral and Craniofacial Sciences, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
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Yao S, Du Z, Xiao L, Yan F, Ivanovski S, Xiao Y. Morphometric Changes of Osteocyte Lacunar in Diabetic Pig Mandibular Cancellous Bone. Biomolecules 2022; 13:biom13010049. [PMID: 36671434 PMCID: PMC9856050 DOI: 10.3390/biom13010049] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 12/12/2022] [Accepted: 12/13/2022] [Indexed: 12/29/2022] Open
Abstract
Osteocytes play an important role in bone metabolism. The interactions of osteocytes with the surrounding microenvironment can alter cellular and lacunar morphological changes. However, objective quantification of osteocyte lacunae is challenging due to their deep location in the bone matrix. This project established a novel method for the analytical study of osteocytes/lacunae, which was then used to evaluate the osteocyte morphological changes in diabetic pig mandibular bone. Eight miniature pigs were sourced, and diabetes was randomly induced in four animals using streptozotocin (STZ) administration. The mandibular tissues were collected and processed. The jawbone density was evaluated with micro-CT. Osteocyte lacunae were effectively acquired and identified using backscattered electron scanning microscopy (BSE). A significantly decreased osteocyte lacunae size was found in the diabetic group. Using the acid etching method, it was demonstrated that the area of osteocyte and lacunae, and the pericellular areas were both significantly reduced in the diabetes group. In conclusion, a standard and relatively reliable method for analyzing osteocyte/lacunae morphological changes under compromised conditions has been successfully established. This method demonstrates that diabetes can significantly decrease osteocyte/lacunae size in a pig's mandibular cancellous bone.
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Affiliation(s)
- Sheng Yao
- School of Mechanical, Medical and Process Engineering, Center of Biomedical Technology, Queensland University of Technology, Brisbane, QLD 4059, Australia
- The First Hospital of Wuhan, Wuhan 430033, China
| | - Zhibin Du
- School of Mechanical, Medical and Process Engineering, Center of Biomedical Technology, Queensland University of Technology, Brisbane, QLD 4059, Australia
| | - Lan Xiao
- School of Mechanical, Medical and Process Engineering, Center of Biomedical Technology, Queensland University of Technology, Brisbane, QLD 4059, Australia
- Australia-China Centre for Tissue Engineering and Regenerative Medicine, Queensland University of Technology, Brisbane, QLD 4059, Australia
| | - Fuhua Yan
- Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing 210008, China
| | - Saso Ivanovski
- School of Dentistry, The University of Queensland, Brisbane, QLD 4006, Australia
| | - Yin Xiao
- School of Mechanical, Medical and Process Engineering, Center of Biomedical Technology, Queensland University of Technology, Brisbane, QLD 4059, Australia
- Australia-China Centre for Tissue Engineering and Regenerative Medicine, Queensland University of Technology, Brisbane, QLD 4059, Australia
- School of Medicine and Dentistry & Menzies Health Institute Queensland, Griffith University, Gold Coast, QLD 4222, Australia
- Correspondence:
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Zhang K, Ogando C, Filip A, Zhang T, Horton JA, Soman P. In vitromodel to study confined osteocyte networks exposed to flow-induced mechanical stimuli. Biomed Mater 2022; 17:10.1088/1748-605X/aca37c. [PMID: 36384043 PMCID: PMC10642715 DOI: 10.1088/1748-605x/aca37c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 11/16/2022] [Indexed: 11/18/2022]
Abstract
Osteocytes are considered the primary mechanical sensor in bone tissue and orchestrate the coupled bone remodeling activity of adjacent osteoblast and osteoclast cells.In vivoinvestigation of mechanically induced signal propagation through networks of interconnected osteocytes is confounded by their confinement within the mineralized bone matrix, which cannot be modeled in conventional culture systems. In this study, we developed a new model that mimics thisin vivoconfinement using gelatin methacrylate (GelMA) hydrogel or GelMA mineralized using osteoblast-like model cells. This model also enables real-time optical examination of osteocyte calcium (Ca2+) signaling dynamics in response to fluid shear stimuli cultured under confined conditions. Using this system, we discovered several distinct and previously undescribed patterns of Ca2+responses that vary across networks of interconnected osteocytes as a function of space, time and connectivity. Heterogeneity in Ca2+signaling may provide new insights into bone remodeling in response to mechanical loading. Overall, such a model can be extended to study signaling dynamics within cell networks exposed to flow-induced mechanical stimuli under confined conditions.
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Affiliation(s)
- Kairui Zhang
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, NY, USA, 13244
- Syracuse Biomaterials Institute, Syracuse, NY, USA, 13244
| | - Courtney Ogando
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, NY, USA, 13244
- Syracuse Biomaterials Institute, Syracuse, NY, USA, 13244
| | - Alex Filip
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, NY, USA, 13244
- Syracuse Biomaterials Institute, Syracuse, NY, USA, 13244
| | - Teng Zhang
- Syracuse Biomaterials Institute, Syracuse, NY, USA, 13244
- Department of Mechanical and Aerospace Engineering, Syracuse University, Syracuse, NY, USA, 13244
| | - Jason A. Horton
- Syracuse Biomaterials Institute, Syracuse, NY, USA, 13244
- Dept. of Orthopedic Surgery, SUNY Upstate Medical University, Syracuse, NY, USA 13210
| | - Pranav Soman
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, NY, USA, 13244
- Syracuse Biomaterials Institute, Syracuse, NY, USA, 13244
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Hong AR, Yang JY, Lee JY, Suh J, Lee YS, Kim JE, Kim SW. Reactivation of Bone Lining Cells are Attenuated Over Repeated Anti-sclerostin Antibody Administration. Calcif Tissue Int 2022; 111:495-505. [PMID: 35925416 DOI: 10.1007/s00223-022-01013-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 07/12/2022] [Indexed: 11/26/2022]
Abstract
Reactivation of bone lining cells (BLCs) is a crucial mechanism governing the anabolic action of anti-sclerostin antibody (Scl-Ab) via modeling-based bone formation; however, it remains unclear whether this reactivation can be attenuated after persistent administration of Scl-Ab. Here, we aimed to investigate the reproducibility of persistent Scl-Ab administration for the reactivation of BLCs, and to elucidate the relationship between the activity of BLCs and serum levels of N-terminal procollagen type I (P1NP) during chronic Scl-Ab administration. We conducted an osteoblast lineage tracing study. Briefly, Dmp1-CreERt2(+):Rosa26R mice were injected with 1 mg of 4-hydroxy-tamoxifen weekly from postnatal weeks four to eight. Mice were treated twice with either vehicle or Scl-Ab (25 mg/kg) at weeks 12, 16, and 20, and were euthanized at weeks 8, 12, 13, 16, 17, 20, and 21 (4-6 mice in each group). After euthanization, the number and thickness of X-gal (+) cells on the periosteum of the femoral bones and the serum levels of P1NP were quantified at each time point. Scl-Ab induced a significant increase in the thickness of X-gal (+) cells on periosteal bone surfaces at postnatal weeks 13 (after 1st dose), 17 (after 2nd dose), and 21 (after 3rd dose) compared to that in vehicle-treated mice (all P < 0.001). In the Scl-Ab group, significant increases in the thickness of labeled cells were observed between weeks 16 and 17 and weeks 20 and 21 (both P < 0.001). The percentage increase in X-gal (+) cell thickness was 108.9% from week 12 to week 13, 54.6% from week 16 to week 17, and 49.2% from week 20 to week 21 in the Scl-Ab group. Although Scl-Ab treatment increased the serum levels of P1NP at postnatal weeks 13 and 17 compared with those at week 12 (P = 0.017 and P = 0.038, respectively), the same was not observed at week 21 (P = 0.296). A significant increase in P1NP levels was observed between weeks 16 and 17 and weeks 20 and 21 in the Scl-Ab group (P = 0.005 and P = 0.007, respectively). The percentage increase in P1NP levels was 141.7% from weeks 12 to 13, 114.8% from weeks 16 to 17, and 99.4% from weeks 20 to 21. Serum P1NP levels were positively correlated with X-gal (+) cell thickness (R2 = 0.732, P < 0.001). Reactivation of BLCs is modestly attenuated, but reproducible, during persistent Scl-Ab administration. Serum P1NP levels appear to be an indicator of the impact of Scl-Ab on the conversion of BLCs into mature osteoblasts on periosteal bone surfaces, thus contributing to modeling-based bone formation.
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Affiliation(s)
- A Ram Hong
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju, South Korea
| | - Jae-Yeon Yang
- Department of Research and Experiment, Seoul National University Hospital Biomedical Research Institute, Seoul, South Korea
| | - Ji Yeon Lee
- Department of Research and Experiment, Seoul National University Hospital Biomedical Research Institute, Seoul, South Korea
| | - Joonho Suh
- Department of Molecular Genetics, School of Dentistry and Dental Research Institute, Seoul National University, Seoul, South Korea
| | - Yun-Sil Lee
- Department of Molecular Genetics, School of Dentistry and Dental Research Institute, Seoul National University, Seoul, South Korea
| | - Jung-Eun Kim
- Department of Molecular Medicine, Cell and Matrix Research Institute, School of Medicine, Kyungpook National University, Daegu, South Korea
| | - Sang Wan Kim
- Department of Internal Medicine, Seoul National University College of Medicine and Boramae Medical Center, 20 Boramae-Ro 5-Gil, Dongjak-Gu, Seoul, 07061, South Korea.
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Wang H, Gao L, Chen X, Zhang C. Study on mass transfer in the bone lacunar-canalicular system under different gravity fields. J Bone Miner Metab 2022; 40:940-950. [PMID: 36350408 DOI: 10.1007/s00774-022-01373-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 09/22/2022] [Indexed: 11/11/2022]
Abstract
INTRODUCTION The bone lacunar-canalicular system (LCS) is an important microstructural basis for signaling and material transport in bone tissue, guaranteeing normal physiological processes in tissues. Spaceflight astronauts and elderly osteoporosis are related to its function, so it is necessary to reveal the mass transfer laws in bone microstructure under different gravity fields to provide insight for effective clinical treatment. MATERIALS AND METHODS Using the natural LCS structure of bovine tibial cortical bone as the object, the mass transfer experiments on cortical bone were conducted by using sodium fluorescein tracer through different frequency pulsating pressure provided by dynamic perfusion loading device and different high G environments provided by high-speed centrifuge to analyze the mass transfer laws under different gravity fields and different pulsating pressures. RESULTS The fluorescence intensity of lacunae within the osteon was lower the farther away from the Haversian canal. As the gravity field magnitude increased, the fluorescence intensity within each lacuna enhanced, and the more distant the lacunae from the Haversian canal, the greater the fluorescence intensity enhancement. High-frequency pulsating pressure simulated high-intensity exercise in humans can improve mass transfer efficiency in the LCS. CONCLUSION High-intensity exercise may greatly increase solute molecules, nutrients, and signaling molecules in osteocytes and improve the activity of osteocytes. Hypergravity can enhance the transport of solute molecules, nutrients, and signaling molecules in the LCS, especially promoting mass transfer to deep layer lacunae. Conversely, mass transfer to deep layer lacunae may be inhibited under microgravity, causing bone loss and ultimately leading to osteoporosis.
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Affiliation(s)
- Hao Wang
- Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control, National Demonstration Center for Experimental Mechanical and Electrical Engineering Education, School of Mechanical Engineering, Tianjin University of Technology, Tianjin, 300384, People's Republic of China
| | - Lilan Gao
- Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control, National Demonstration Center for Experimental Mechanical and Electrical Engineering Education, School of Mechanical Engineering, Tianjin University of Technology, Tianjin, 300384, People's Republic of China
| | - Xuyi Chen
- Characteristic Medical Center of People's Armed Police Forces, Institute of Brain Trauma and Neurological Diseases of the Armed Police Force, Tianjin, People's Republic of China.
| | - Chunqiu Zhang
- Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control, National Demonstration Center for Experimental Mechanical and Electrical Engineering Education, School of Mechanical Engineering, Tianjin University of Technology, Tianjin, 300384, People's Republic of China.
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Chai RC. Single-Cell RNA Sequencing: Unravelling the Bone One Cell at a Time. Curr Osteoporos Rep 2022; 20:356-362. [PMID: 35915289 PMCID: PMC9522837 DOI: 10.1007/s11914-022-00735-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/11/2022] [Indexed: 11/03/2022]
Abstract
PURPOSE OF REVIEW Bone is a complex tissue populated by a highly heterogeneous mix of cell types in different compartments. The endosteal compartment is a key site for bone remodelling and provides a supportive microenvironment to harbour haematopoietic and mesenchymal stem cells, as well as cancer cells that grow in bone. The purpose of this review is to summarize recent findings of studies in bone using single-cell RNA sequencing and emergent spatial RNA sequencing to describe different bone-resident cell types and their molecular programs. RECENT FINDINGS Single-cell RNA sequencing identified novel and transcriptionally distinct cell clusters within different bone cell lineages, including MSCs, osteoblasts, chondrocytes, fibroblasts, osteoclasts and cells of the vasculature. Spatial transcriptomics methods provide information on the localization of the different cell populations. Single-cell transcriptomics provided valuable insights into long-standing knowledge gaps in the cellular heterogeneity of bone-resident cells in unprecedented detail, paving the way for studies to further investigate the different cell populations and to develop cell-based therapies for bone diseases.
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Affiliation(s)
- Ryan C Chai
- Bone Biology Laboratory, Garvan Institute of Medical Research, Darlinghurst, NSW, Australia.
- St. Vincent's Clinical School, Faculty of Medicine, UNSW Sydney, Kensington, NSW, Australia.
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Wee NKY, de Lima TFC, McGregor NE, Walker EC, Poulton IJ, Blank M, Sims NA. Leptin receptor in osteocytes promotes cortical bone consolidation in female mice. J Endocrinol 2022; 255:25-37. [PMID: 35938692 DOI: 10.1530/joe-22-0084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Accepted: 08/01/2022] [Indexed: 11/08/2022]
Abstract
Bone strength is partially determined during cortical bone consolidation, a process comprising coalescence of peripheral trabecular bone and its progressive mineralisation. Mice with genetic deletion of suppressor of cytokine signalling 3 (Socs3), an inhibitor of STAT3 signalling, exhibit delayed cortical bone consolidation, indicated by high cortical porosity, low mineral content, and low bone strength. Since leptin receptor (LepR) is expressed in the osteoblast lineage and is suppressed by SOCS3, we evaluated whether LepR deletion in osteocytes would rectify the Dmp1cre.Socs3fl/fl bone defect. First, we tested LepR deletion in osteocytes by generating Dmp1cre.LepRfl/fl mice and detected no significant bone phenotype. We then generated Dmp1cre.Socs3fl/fl.LepRfl/fl mice and compared them to Dmp1cre.Socs3fl/fl controls. Between 6 and 12 weeks of age, both Dmp1cre.Socs3fl/fl.LepRfl/fl and control (Dmp1cre.Socs3fl/fl) mice showed an increasing proportion of more heavily mineralised bone, indicating some cortical consolidation with time. However, at 12 weeks of age, rather than resolving the phenotype, delayed consolidation was extended in female Dmp1cre.Socs3fl/fl.LepRfl/fl mice. This was indicated in both metaphysis and diaphysis by greater proportions of low-density bone, lower proportions of high-density bone, and greater cortical porosity than Dmp1cre.Socs3fl/fl controls. There was also no change in the proportion of osteocytes staining positive for phospho-STAT3, suggesting the effect of LepR deletion in Dmp1cre.Socs3fl/fl mice is STAT3-independent. This identifies a new role for leptin signalling in bone which opposes our original hypothesis. Although LepR in osteocytes has no irreplaceable physiological role in normal bone maturation, when STAT3 is hyperactive, LepR in Dmp1Cre-expressing cells supports cortical consolidation.
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Affiliation(s)
- Natalie K Y Wee
- Bone Cell Biology and Disease Unit, St Vincent's Institute of Medical Research, Fitzroy, Australia
| | - Thaísa F C de Lima
- Bone Cell Biology and Disease Unit, St Vincent's Institute of Medical Research, Fitzroy, Australia
- Department of Genetics and Molecular Biology, University of Campinas, São Paulo, Brazil
| | - Narelle E McGregor
- Bone Cell Biology and Disease Unit, St Vincent's Institute of Medical Research, Fitzroy, Australia
| | - Emma C Walker
- Bone Cell Biology and Disease Unit, St Vincent's Institute of Medical Research, Fitzroy, Australia
| | - Ingrid J Poulton
- Bone Cell Biology and Disease Unit, St Vincent's Institute of Medical Research, Fitzroy, Australia
| | - Martha Blank
- Bone Cell Biology and Disease Unit, St Vincent's Institute of Medical Research, Fitzroy, Australia
- Department of Medicine, The University of Melbourne, St. Vincent's Hospital, Melbourne, Australia
| | - Natalie A Sims
- Bone Cell Biology and Disease Unit, St Vincent's Institute of Medical Research, Fitzroy, Australia
- Department of Medicine, The University of Melbourne, St. Vincent's Hospital, Melbourne, Australia
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Hasegawa T, Hongo H, Yamamoto T, Abe M, Yoshino H, Haraguchi-Kitakamae M, Ishizu H, Shimizu T, Iwasaki N, Amizuka N. Matrix Vesicle-Mediated Mineralization and Osteocytic Regulation of Bone Mineralization. Int J Mol Sci 2022; 23:ijms23179941. [PMID: 36077336 PMCID: PMC9456179 DOI: 10.3390/ijms23179941] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 08/23/2022] [Accepted: 08/29/2022] [Indexed: 11/16/2022] Open
Abstract
Bone mineralization entails two mineralization phases: primary and secondary mineralization. Primary mineralization is achieved when matrix vesicles are secreted by osteoblasts, and thereafter, bone mineral density gradually increases during secondary mineralization. Nearby extracellular phosphate ions (PO43−) flow into the vesicles via membrane transporters and enzymes located on the vesicles’ membranes, while calcium ions (Ca2+), abundant in the tissue fluid, are also transported into the vesicles. The accumulation of Ca2+ and PO43− in the matrix vesicles induces crystal nucleation and growth. The calcium phosphate crystals grow radially within the vesicle, penetrate the vesicle’s membrane, and continue to grow outside the vesicle, ultimately forming mineralized nodules. The mineralized nodules then attach to collagen fibrils, mineralizing them from the contact sites (i.e., collagen mineralization). Afterward, the bone mineral density gradually increases during the secondary mineralization process. The mechanisms of this phenomenon remain unclear, but osteocytes may play a key role; it is assumed that osteocytes enable the transport of Ca2+ and PO43− through the canaliculi of the osteocyte network, as well as regulate the mineralization of the surrounding bone matrix via the Phex/SIBLINGs axis. Thus, bone mineralization is biologically regulated by osteoblasts and osteocytes.
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Affiliation(s)
- Tomoka Hasegawa
- Developmental Biology of Hard Tissue, Graduate School of Dental Medicine, Faculty of Dental Medicine, Hokkaido University, Sapporo 060-8586, Japan
- Correspondence: (T.H.); (N.A.); Tel.: +81-11-706-4226 (T.H.); +81-11-706-4223 (N.A.)
| | - Hiromi Hongo
- Developmental Biology of Hard Tissue, Graduate School of Dental Medicine, Faculty of Dental Medicine, Hokkaido University, Sapporo 060-8586, Japan
| | - Tomomaya Yamamoto
- Developmental Biology of Hard Tissue, Graduate School of Dental Medicine, Faculty of Dental Medicine, Hokkaido University, Sapporo 060-8586, Japan
- Northern Army Medical Unit, Camp Makomanai, Japan Ground Self-Defense Forces, Sapporo 005-8543, Japan
| | - Miki Abe
- Developmental Biology of Hard Tissue, Graduate School of Dental Medicine, Faculty of Dental Medicine, Hokkaido University, Sapporo 060-8586, Japan
| | - Hirona Yoshino
- Developmental Biology of Hard Tissue, Graduate School of Dental Medicine, Faculty of Dental Medicine, Hokkaido University, Sapporo 060-8586, Japan
| | - Mai Haraguchi-Kitakamae
- Developmental Biology of Hard Tissue, Graduate School of Dental Medicine, Faculty of Dental Medicine, Hokkaido University, Sapporo 060-8586, Japan
- Division of Craniofacial Development and Tissue Biology, Graduate School of Dentistry, Tohoku University, Sendai 980-8577, Japan
| | - Hotaka Ishizu
- Developmental Biology of Hard Tissue, Graduate School of Dental Medicine, Faculty of Dental Medicine, Hokkaido University, Sapporo 060-8586, Japan
- Orthopedic Surgery, Faculty of Medicine, Hokkaido University, Sapporo 060-8638, Japan
| | - Tomohiro Shimizu
- Orthopedic Surgery, Faculty of Medicine, Hokkaido University, Sapporo 060-8638, Japan
| | - Norimasa Iwasaki
- Orthopedic Surgery, Faculty of Medicine, Hokkaido University, Sapporo 060-8638, Japan
| | - Norio Amizuka
- Developmental Biology of Hard Tissue, Graduate School of Dental Medicine, Faculty of Dental Medicine, Hokkaido University, Sapporo 060-8586, Japan
- Correspondence: (T.H.); (N.A.); Tel.: +81-11-706-4226 (T.H.); +81-11-706-4223 (N.A.)
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Weng B, Chen C. Effects of Bisphosphonate on Osteocyte Proliferation and Bone Formation in Patients with Diabetic Osteoporosis. Comput Math Methods Med 2022; 2022:2368564. [PMID: 35844452 PMCID: PMC9279083 DOI: 10.1155/2022/2368564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 06/07/2022] [Accepted: 06/18/2022] [Indexed: 11/28/2022]
Abstract
Background Bisphosphonate is currently considered one of the drugs for the first-line treatment of osteoporosis because of its ability to inhibit bone resorption, but the molecular mechanism of its effect on osteocyte proliferation and bone formation of diabetic osteoporosis is still unclear. Objective To confirm the potential effect on of bisphosphonate on osteocyte proliferation and bone formation in patients having diabetic osteoporosis (DO). Methods Sixty DO patients admitted to our hospital from February 2019 to April 2021 were randomly selected and divided into the bisphosphonate group and the control group. The total incidence, incidence of hip fracture, efficacy, bone mineral density, osteocalcin, pain score, osteocyte proliferation, bone formation index, serum calcium, and phosphorus contents were compared between two groups. Results The curative effect of bisphosphonic acid group was better than that of control group, and the difference was statistically significant (P < 0.05). Compared with the control group, the bone mineral density and osteocalcin in the bisphosphonic acid group were significantly improved after treatment, and the pain score in the bisphosphonic acid group was significantly lower than that in the control group (P < 0.05). After intervention treatment, the OD and PINP values in the bisphosphonate group were significantly different from those in the control group (P < 0.05). After treatment, the contents of serum calcium and phosphorus in the bisphosphonic acid group were significantly higher than those in the control group (P < 0.05). The incidence of hip fracture, spinal fracture, and other fractures in the bisphosphonic acid group was significantly lower than that in the control group (P < 0.05). Conclusion The treatment of DO with bisphosphonate is capability of effectively improving bone cell proliferation and bone formation, further alleviating clinical symptoms and promoting the improvement of the disease.
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Affiliation(s)
- Beifang Weng
- Department of Orthopaedics and Traumatology, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai 200120, China
| | - Chunhua Chen
- Department of Orthopaedics and Traumatology, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai 200120, China
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Watanabe R, Matsugaki A, Ishimoto T, Ozasa R, Matsumoto T, Nakano T. A Novel Ex Vivo Bone Culture Model for Regulation of Collagen/Apatite Preferential Orientation by Mechanical Loading. Int J Mol Sci 2022; 23:ijms23137423. [PMID: 35806427 PMCID: PMC9267238 DOI: 10.3390/ijms23137423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 06/29/2022] [Accepted: 07/01/2022] [Indexed: 11/16/2022] Open
Abstract
The anisotropic microstructure of bone, composed of collagen fibers and biological apatite crystallites, is an important determinant of its mechanical properties. Recent studies have revealed that the preferential orientation of collagen/apatite composites is closely related to the direction and magnitude of in vivo principal stress. However, the mechanism of alteration in the collagen/apatite microstructure to adapt to the mechanical environment remains unclear. In this study, we established a novel ex vivo bone culture system using embryonic mouse femurs, which enabled artificial control of the mechanical environment. The mineralized femur length significantly increased following cultivation; uniaxial mechanical loading promoted chondrocyte hypertrophy in the growth plates of embryonic mouse femurs. Compressive mechanical loading using the ex vivo bone culture system induced a higher anisotropic microstructure than that observed in the unloaded femur. Osteocytes in the anisotropic bone microstructure were elongated and aligned along the long axis of the femur, which corresponded to the principal loading direction. The ex vivo uniaxial mechanical loading successfully induced the formation of an oriented collagen/apatite microstructure via osteocyte mechano-sensation in a manner quite similar to the in vivo environment.
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Affiliation(s)
- Ryota Watanabe
- Division of Materials and Manufacturing Science, Graduate School of Engineering, Osaka University, Suita 565-0871, Japan; (R.W.); (A.M.); (T.I.); (R.O.)
- Teijin Nakashima Medical Co., Ltd., 688-1 Joto-Kitagata, Higashi-ku, Okayama 709-0625, Japan
| | - Aira Matsugaki
- Division of Materials and Manufacturing Science, Graduate School of Engineering, Osaka University, Suita 565-0871, Japan; (R.W.); (A.M.); (T.I.); (R.O.)
| | - Takuya Ishimoto
- Division of Materials and Manufacturing Science, Graduate School of Engineering, Osaka University, Suita 565-0871, Japan; (R.W.); (A.M.); (T.I.); (R.O.)
| | - Ryosuke Ozasa
- Division of Materials and Manufacturing Science, Graduate School of Engineering, Osaka University, Suita 565-0871, Japan; (R.W.); (A.M.); (T.I.); (R.O.)
| | - Takuya Matsumoto
- Department of Biomaterials, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1, Shikata-cho, Kita-ku, Okayama 700-8558, Japan;
| | - Takayoshi Nakano
- Division of Materials and Manufacturing Science, Graduate School of Engineering, Osaka University, Suita 565-0871, Japan; (R.W.); (A.M.); (T.I.); (R.O.)
- Correspondence: ; Tel.: +81-6-6879-7505
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Tabata K, Hashimoto M, Takahashi H, Wang Z, Nagaoka N, Hara T, Kamioka H. A morphometric analysis of the osteocyte canaliculus using applied automatic semantic segmentation by machine learning. J Bone Miner Metab 2022; 40:571-580. [PMID: 35338405 DOI: 10.1007/s00774-022-01321-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 02/22/2022] [Indexed: 02/07/2023]
Abstract
INTRODUCTION Osteocytes play a role as mechanosensory cells by sensing flow-induced mechanical stimuli applied on their cell processes. High-resolution imaging of osteocyte processes and the canalicular wall are necessary for the analysis of this mechanosensing mechanism. Focused ion beam-scanning electron microscopy (FIB-SEM) enabled the visualization of the structure at the nanometer scale with thousands of serial-section SEM images. We applied machine learning for the automatic semantic segmentation of osteocyte processes and canalicular wall and performed a morphometric analysis using three-dimensionally reconstructed images. MATERIALS AND METHODS Six-week-old-mice femur were used. Osteocyte processes and canaliculi were observed at a resolution of 2 nm/voxel in a 4 × 4 μm region with 2000 serial-section SEM images. Machine learning was used for automatic semantic segmentation of the osteocyte processes and canaliculi from serial-section SEM images. The results of semantic segmentation were evaluated using the dice similarity coefficient (DSC). The segmented data were reconstructed to create three-dimensional images and a morphological analysis was performed. RESULTS The DSC was > 83%. Using the segmented data, a three-dimensional image of approximately 3.5 μm in length was reconstructed. The morphometric analysis revealed that the median osteocyte process diameter was 73.8 ± 18.0 nm, and the median pericellular fluid space around the osteocyte process was 40.0 ± 17.5 nm. CONCLUSION We used machine learning for the semantic segmentation of osteocyte processes and canalicular wall for the first time, and performed a morphological analysis using three-dimensionally reconstructed images.
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Affiliation(s)
- Kaori Tabata
- Department of Orthodontics, Okayama University Hospital, Okayama, Japan
| | - Mana Hashimoto
- Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata, Kita-ku, Okayama, Okayama, 700-8558, Japan
| | - Haruka Takahashi
- Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata, Kita-ku, Okayama, Okayama, 700-8558, Japan
| | - Ziyi Wang
- Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata, Kita-ku, Okayama, Okayama, 700-8558, Japan
| | - Noriyuki Nagaoka
- Advanced Research Center for Oral and Craniofacial Sciences, Okayama University Dental School, Okayama, Japan
| | - Toru Hara
- Research Center for Structural Materials, National Institute for Materials Science, Tsukuba, Japan
| | - Hiroshi Kamioka
- Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata, Kita-ku, Okayama, Okayama, 700-8558, Japan.
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Wittig NK, Birkedal H. Bone hierarchical structure: spatial variation across length scales. Acta Crystallogr B Struct Sci Cryst Eng Mater 2022; 78:305-311. [PMID: 35695104 DOI: 10.1107/s2052520622001524] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 02/08/2022] [Indexed: 06/15/2023]
Abstract
Bone is a complex hierarchical biomineralized material, which is special amongst biominerals because it is replete with cells, namely, osteocytes. While bone has been scrutinized for centuries, many questions remain open and new research hints that the ultrastructure of bone, encompassing both the bone matrix itself and the embedded cell network, is much more heterogeneous than hitherto realized. A number of these new findings have been made thanks to the enormous developments in X-ray imaging that have occurred in recent decades, and there is promise that they will also allow many of the remaining open questions to be addressed. X-ray absorption or phase imaging affords high three-dimensional (3D) resolution and allows traversing the length scales of bone all the way down to the fine details of the lacuno-canalicular network housing the osteocytes. Multimodal X-ray imaging provides combined information covering both the length scales defined by the size of the measured volume and tomographic resolution, as well as those probed by the signal that is measured. In X-ray diffraction computed tomography (XRD-CT), for example, diffraction signals can be reconstructed tomographically, which offers detailed information about the spatial variations in the crystallographic properties of the bone biomineral. Orientational information can be obtained by tensor tomography. The combination of both small-angle X-ray scattering (SAXS) and wide-angle X-ray scattering (WAXS) tensor tomography gives information on the orientation of bone nanostructure and crystals, respectively. These new technical developments promise that great strides towards understanding bone structure can be expected in the near future. In this review, recent findings that have resulted from X-ray imaging are highlighted and speculation is given on what can be expected to follow.
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Affiliation(s)
- Nina K Wittig
- Department of Chemistry and iNANO, Aarhus University, 14 Gustav Wieds Vej, Aarhus 8000, Denmark
| | - Henrik Birkedal
- Department of Chemistry and iNANO, Aarhus University, 14 Gustav Wieds Vej, Aarhus 8000, Denmark
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Wang H, Du T, Li R, Main RP, Yang H. Interactive effects of various loading parameters on the fluid dynamics within the lacunar-canalicular system for a single osteocyte. Bone 2022; 158:116367. [PMID: 35181573 DOI: 10.1016/j.bone.2022.116367] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 02/11/2022] [Accepted: 02/11/2022] [Indexed: 12/26/2022]
Abstract
The osteocyte lacunar-canalicular system (LCS) serves as a mechanotransductive core where external loading applied to the skeleton is transduced into mechanical signals (e.g., fluid shear) that can be sensed by mechanosensors (osteocytes). The fluid velocity and shear stress within the LCS are affected by various loading parameters. However, the interactive effect of distinct loading parameters on the velocity and shear stress in the LCS remains unclear. To address this issue, we developed a multiscale modeling approach, combining a poroelastic finite element (FE) model with a single osteocytic LCS unit model to calculate the flow velocity and shear stress within the LCS. Next, a sensitivity analysis was performed to investigate individual and interactive effects of strain magnitude, strain rate, number of cycles, and intervening short rests between loading cycles on the velocity and shear stress around the osteocyte. Lastly, we developed a relatively simple regression model to predict those outcomes. Our results demonstrated that the strain magnitude or rate alone were the main factors affecting the velocity and shear stress; however, the combination of these two was not directly additive, and addition of a short rest between cycles could enhance the combination of these two related factors. These results show highly interactive effects of distinct loading parameters on fluid velocity and shear stress in the LCS. Specifically, our results suggest that an enhanced fluid dynamics environment in the LCS can be achieved with a brief number of load cycles combined with short rest insertion and high strain magnitude and rate.
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Affiliation(s)
- Huiru Wang
- Department of Biomedical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China
| | - Tianming Du
- Department of Biomedical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China
| | - Rui Li
- Department of Biomedical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China
| | - Russell P Main
- Musculoskeletal Biology and Mechanics Lab, Department of Basic Medical Sciences, Purdue University, IN, USA; Weldon School of Biomedical Engineering, Purdue University, IN, USA
| | - Haisheng Yang
- Department of Biomedical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China.
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Rooney AM, Ayobami OO, Kelly NH, Schimenti JC, Ross FP, van der Meulen MCH. Bone mass and adaptation to mechanical loading are sexually dimorphic in adult osteoblast-specific ERα knockout mice. Bone 2022; 158:116349. [PMID: 35123146 DOI: 10.1016/j.bone.2022.116349] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 01/20/2022] [Accepted: 01/31/2022] [Indexed: 12/14/2022]
Abstract
Estrogen receptor-alpha (ERα) regulates bone mass and is implicated in bone tissue's response to mechanical loading. The effects of ERα deletion in mice depend on sex, anatomical location, and the cellular stage at which ERα is removed. Few studies have investigated the effect of age on the role of ERα in skeletal maintenance and functional adaptation. We previously demonstrated that bone mass and adaptation to loading were altered in growing 10-week-old female and male mice lacking ERα in mature osteoblasts and osteocytes (pOC-ERαKO). Here our goal was to determine the effects of ERα and mechanical loading in skeletally-mature adult mice. We subjected 26-week-old skeletally-mature adult pOC-ERαKO and littermate control (LC) mice of both sexes to two weeks of in vivo cyclic tibial loading. ERα deletion in male mice did not alter bone mass or the response to loading. Adult female pOC-ERαKO mice had reduced cancellous and cortical bone mass and increased adaptation to high-magnitude mechanical loading compared to LC mice. Thus, ERα deletion from mature osteoblasts reduced the bone mass and increased the mechanoadaptation of adult female but not male mice. Additionally, compared to our previous work in young mice, adult female mice had greatly reduced mechanoadaptation and adult male mice retained most of their mechanoadaptation with age.
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Affiliation(s)
- Amanda M Rooney
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY 14853, USA.
| | - Olufunmilayo O Ayobami
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY 14853, USA.
| | - Natalie H Kelly
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY 14853, USA.
| | - John C Schimenti
- College of Veterinary Medicine, Cornell University, Ithaca 14853, NY, USA.
| | - F Patrick Ross
- Research Division, Hospital for Special Surgery, New York, NY 10021, USA.
| | - Marjolein C H van der Meulen
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY 14853, USA; Research Division, Hospital for Special Surgery, New York, NY 10021, USA.
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Moriishi T, Komori T. Osteocytes: Their Lacunocanalicular Structure and Mechanoresponses. Int J Mol Sci 2022; 23:ijms23084373. [PMID: 35457191 PMCID: PMC9032292 DOI: 10.3390/ijms23084373] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 04/13/2022] [Accepted: 04/13/2022] [Indexed: 11/29/2022] Open
Abstract
Osteocytes connect with neighboring osteocytes and osteoblasts through their processes and form an osteocyte network. Shear stress on osteocytes, which is induced by fluid flow in the lacunae and canaliculi, has been proposed as an important mechanism for mechanoresponses. The lacunocanalicular structure is differentially developed in the compression and tension sides of femoral cortical bone and the compression side is more organized and has denser and thinner canaliculi. Mice with an impaired lacunocanalicular structure may be useful for evaluation of the relationship between lacunocanalicular structure and mechanoresponses, although their bone component cells are not normal. We show three examples of mice with an impaired lacunocanalicular structure. Ablation of osteocytes by diphtheria toxin caused massive osteocyte apoptosis, necrosis or secondary necrosis that occurred after apoptosis. Osteoblast-specific Bcl2 transgenic mice were found to have a reduced number of osteocyte processes and canaliculi, which caused massive osteocyte apoptosis and a completely interrupted lacunocanalicular network. Osteoblast-specific Sp7 transgenic mice were also revealed to have a reduced number of osteocyte processes and canaliculi, as well as an impaired, but functionally connected, lacunocanalicular network. Here, we show the phenotypes of these mice in physiological and unloaded conditions and deduce the relationship between lacunocanalicular structure and mechanoresponses.
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Affiliation(s)
- Takeshi Moriishi
- Department of Cell Biology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852-8588, Japan;
| | - Toshihisa Komori
- Department of Molecular Bone Biology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852-8588, Japan
- Correspondence: ; Tel.: +81-95-819-7637; Fax: +81-95-819-7638
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Rux CJ, Vahidi G, Darabi A, Cox LM, Heveran CM. Perilacunar bone tissue exhibits sub-micrometer modulus gradation which depends on the recency of osteocyte bone formation in both young adult and early-old-age female C57Bl/6 mice. Bone 2022; 157:116327. [PMID: 35026452 PMCID: PMC8858864 DOI: 10.1016/j.bone.2022.116327] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 12/19/2021] [Accepted: 01/07/2022] [Indexed: 11/18/2022]
Abstract
Osteocytes resorb and replace bone local to the lacunar-canalicular system (LCS). However, whether osteocyte remodeling impacts bone quality adjacent to the LCS is not understood. Further, while aging is well-established to decrease osteocyte viability and truncate LCS geometry, it is unclear if aging also decreases perilacunar bone quality. To address these questions, we employed atomic force microscopy (AFM) to generate nanoscale-resolution modulus maps for cortical femur osteocyte lacunae from young (5-month) and early-old-age (22-month) female C57Bl/6 mice. AFM-mapped lacunae were also imaged with confocal laser scanning microscopy to determine which osteocytes recently deposited bone as determined by the presence of fluorochrome labels administered 2d and 8d before euthanasia. Modulus gradation with distance from the lacunar wall was compared for labeled (i.e., bone forming) and non-labeled lacunae in both young and aged mice. All mapped lacunae showed sub-microscale modulus gradation, with peak modulus values 200-400 nm from the lacunar wall. Perilacunar modulus gradations depended on the recency of osteocyte bone formation (i.e., the presence of labels). For both ages, 2d-labeled perilacunar bone had lower peak and bulk modulus compared to non-labeled perilacunar bone. Lacunar length reduced with age, but lacunar shape and size were not strong predictors of modulus gradation. Our findings demonstrate for the first time that osteocyte perilacunar remodeling impacts bone tissue modulus, one contributor to bone quality. Given the immense scale of the LCS, differences in perilacunar modulus resulting from osteocyte remodeling activity may affect the quality of a substantial amount of bone tissue.
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Affiliation(s)
- Caleb J Rux
- Department of Mechanical & Industrial Engineering, Montana State University, United States of America; UC Berkeley-UCSF Graduate Program in Bioengineering, United States of America
| | - Ghazal Vahidi
- Department of Mechanical & Industrial Engineering, Montana State University, United States of America
| | - Amir Darabi
- Department of Mechanical & Industrial Engineering, Montana State University, United States of America
| | - Lewis M Cox
- Department of Mechanical & Industrial Engineering, Montana State University, United States of America
| | - Chelsea M Heveran
- Department of Mechanical & Industrial Engineering, Montana State University, United States of America.
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Liu Y, Ruan X, Li J, Wang B, Chen J, Wang X, Wang P, Tu X. The Osteocyte Stimulated by Wnt Agonist SKL2001 Is a Safe Osteogenic Niche Improving Bioactivities in a Polycaprolactone and Cell Integrated 3D Module. Cells 2022; 11:cells11050831. [PMID: 35269452 PMCID: PMC8909416 DOI: 10.3390/cells11050831] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 01/19/2022] [Accepted: 01/25/2022] [Indexed: 02/05/2023] Open
Abstract
Finding and constructing an osteogenic microenvironment similar to natural bone tissue has always been a frontier topic in orthopedics. We found that osteocytes are targeting cells controlling bone anabolism produced by PTH (JBMR 2017, PMID: 27704638), and osteocytes with activated Wnt signaling orchestrate bone formation and resorption (PNAS 2015, PMID: 25605937). However, methods for taking advantage of the leading role of osteocytes in bone regeneration remain unexplored. Herein, we found that the osteocytes with SKL2001-activated Wnt signaling could be an osteogenic microenvironment (SOOME) which upregulates the expression of bone transcription factor Runx2 and Bglap and promotes the differentiation of bone marrow stromal cell ST2 into osteoblasts. Interestingly, 60 μM SKL2001 treatment of osteocytic MLO-Y4 for 24 h maintained Wnt signaling activation for three days after removal, which was sufficient to induce osteoblast differentiation. Triptonide, a Wnt inhibitor, could eliminate this differentiation. Moreover, on day 5, the Wnt signaling naturally decreased to the level of the control group, indicating that this method of Wnt-signaling induction is safe to use. We quickly verified in vivo function of SOOME to a good proximation in 3D bioprinted modules composed of reciprocally printed polycaprolactone bundles (for support) and cell bundles (for bioactivity). In the cell bundles, SOOME stably supported the growth and development of ST2 cells, the 7-day survival rate was as high as 91.6%, and proliferation ability increased linearly. Similarly, SOOME greatly promoted ST2 differentiation and mineralization for 28 days. In addition, SOOME upregulated the expression of angiopoietin 1, promoted endothelial cell migration and angiogenesis, and increased node number and total length of tubes and branches. Finally, we found that the function of SOOME could be realized through the paracrine pathway. This study reveals that osteocytes with Wnt signaling activated by SKL2001 are a safe osteogenic microenvironment. Both SOOME itself and its cell-free culture supernatant can improve bioactivity for osteoblast differentiation, with composite scaffolds especially bearing application value.
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Affiliation(s)
| | | | | | | | | | | | | | - Xiaolin Tu
- Correspondence: ; Tel.: +86-185-2382-0685
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Birkedal H. Comment on Quantitative Evaluation of Osteocyte Morphology and Bone Anisotropic Extracellular Matrix in Rat Femur. Calcif Tissue Int 2022; 110:143. [PMID: 34374816 DOI: 10.1007/s00223-021-00902-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 07/31/2021] [Indexed: 10/20/2022]
Affiliation(s)
- Henrik Birkedal
- Department of Chemistry and iNANO, Aarhus University, 14 Gustav Wieds Vej, 8000, Aarhus, Denmark.
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Bouchard AL, Dsouza C, Julien C, Rummler M, Gaumond MH, Cermakian N, Willie BM. Bone adaptation to mechanical loading in mice is affected by circadian rhythms. Bone 2022; 154:116218. [PMID: 34571201 DOI: 10.1016/j.bone.2021.116218] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 09/13/2021] [Accepted: 09/22/2021] [Indexed: 11/28/2022]
Abstract
Physical forces are critical for successful function of many organs including bone. Interestingly, the timing of exercise during the day alters physiology and gene expression in many organs due to circadian rhythms. Circadian clocks in tissues, such as bone, express circadian clock genes that target tissue-specific genes, resulting in tissue-specific rhythmic gene expression (clock-controlled genes). We hypothesized that the adaptive response of bone to mechanical loading is regulated by circadian rhythms. First, mice were sham loaded and sacrificed 8 h later, which amounted to tissues being collected at zeitgeber time (ZT)2, 6, 10, 14, 18, and 22. Cortical bone of the tibiae collected from these mice displayed diurnal expression of core clock genes and key osteocyte and osteoblast-related genes, such as the Wnt-signaling inhibitors Sost and Dkk1, indicating these are clock-controlled genes. Serum bone turnover markers did not display rhythmicity. Second, mice underwent a single bout of in vivo loading at either ZT2 or ZT14 and were sacrificed 1, 8, or 24 h after loading. Loading at ZT2 resulted in Sost upregulation, while loading at ZT14 led to Sost and Dkk1 downregulation. Third, mice underwent daily in vivo tibial loading over 2 weeks administered either in the morning, (ZT2, resting phase) or evening (ZT14, active phase). In vivo microCT was performed at days 0, 5, 10, and 15 and conventional histomorphometry was performed at day 15. All outcome measures indicated a robust response to loading, but only microCT-based time-lapse morphometry showed that loading at ZT14 resulted in a greater endocortical bone formation response compared to mice loaded at ZT2. The decreased Sost and Dkk1 expression coincident with the modest, but significant time-of-day specific increase in adaptive bone formation, suggests that circadian clocks influence bone mechanoresponse.
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Affiliation(s)
- Alice L Bouchard
- Research Centre, Shriners Hospital for Children-Canada, Montreal, Canada; Department of Pediatric Surgery, McGill University, Montreal, Canada; Department of Experimental Surgery, McGill University, Montreal, Canada
| | - Chrisanne Dsouza
- Research Centre, Shriners Hospital for Children-Canada, Montreal, Canada; Department of Pediatric Surgery, McGill University, Montreal, Canada; Department of Experimental Surgery, McGill University, Montreal, Canada
| | - Catherine Julien
- Research Centre, Shriners Hospital for Children-Canada, Montreal, Canada; Department of Pediatric Surgery, McGill University, Montreal, Canada
| | - Maximilian Rummler
- Research Centre, Shriners Hospital for Children-Canada, Montreal, Canada; Department of Pediatric Surgery, McGill University, Montreal, Canada; Department of Experimental Surgery, McGill University, Montreal, Canada
| | - Marie-Hélène Gaumond
- Research Centre, Shriners Hospital for Children-Canada, Montreal, Canada; Department of Pediatric Surgery, McGill University, Montreal, Canada
| | - Nicolas Cermakian
- Laboratory of Molecular Chronobiology, Douglas Research Centre, Montreal, Canada; Department of Psychiatry, McGill University, Montreal, Canada
| | - Bettina M Willie
- Research Centre, Shriners Hospital for Children-Canada, Montreal, Canada; Department of Pediatric Surgery, McGill University, Montreal, Canada; Department of Experimental Surgery, McGill University, Montreal, Canada.
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