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Suh J, Lee YS. The multifaceted roles of mitochondria in osteoblasts: from energy production to mitochondrial-derived vesicle secretion. J Bone Miner Res 2024; 39:1205-1214. [PMID: 38907370 PMCID: PMC11371665 DOI: 10.1093/jbmr/zjae088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 05/03/2024] [Indexed: 06/24/2024]
Abstract
Mitochondria in osteoblasts have been demonstrated to play multiple crucial functions in bone formation from intracellular adenosine triphosphate production to extracellular secretion of mitochondrial components. The present review explores the current knowledge about mitochondrial biology in osteoblasts, including mitochondrial biogenesis, bioenergetics, oxidative stress generation, and dynamic changes in morphology. Special attention is given to recent findings, including mitochondrial donut formation in osteoblasts, which actively generates mitochondrial-derived vesicles (MDVs), followed by extracellular secretion of small mitochondria and MDVs. We also discuss the therapeutic effects of targeting osteoblast mitochondria, highlighting their potential applications in improving bone health.
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Affiliation(s)
- Joonho Suh
- Department of Molecular Genetics, School of Dentistry and Dental Research Institute, Seoul National University, Seoul 08826, Republic of Korea
| | - Yun-Sil Lee
- Department of Molecular Genetics, School of Dentistry and Dental Research Institute, Seoul National University, Seoul 08826, Republic of Korea
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2
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Müller WEG, Schepler H, Neufurth M, Dobmeyer R, Batel R, Schröder HC, Wang X. Energy level as a theranostic factor for successful therapy of tissue injuries with polyphosphate: the triad metabolic energy - mechanical energy - heat. Theranostics 2024; 14:5262-5280. [PMID: 39267793 PMCID: PMC11388067 DOI: 10.7150/thno.100622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2024] [Accepted: 08/09/2024] [Indexed: 09/15/2024] Open
Abstract
Rationale: Tissue regeneration of skin and bone is an energy-intensive, ATP-consuming process that, if impaired, can lead to the development of chronic clinical pictures. ATP levels in the extracellular space including the exudate of wounds, especially chronic wounds, are low. This deficiency can be compensated by inorganic polyphosphate (polyP) supplied via the blood platelets to the regenerating site. Methods: The contribution of the different forms of energy derived from polyP (metabolic energy, mechanical energy and heat) to regeneration processes was dissected and studied both in vitro and in patients. ATP is generated metabolically during the enzymatic cleavage of the energy-rich anhydride bonds between the phosphate units of polyP, involving the two enzymes alkaline phosphatase (ALP) and adenylate kinase (ADK). Exogenous polyP was administered after incorporation into compressed collagen or hydrogel wound coverages to evaluate its regenerative activity for chronic wound healing. Results: In a proof-of-concept study, fast healing of chronic wounds was achieved with the embedded polyP, supporting the crucial regeneration-promoting activity of ATP. In the presence of Ca2+ in the wound exudate, polyP undergoes a coacervation process leading to a conversion of fibroblasts into myofibroblasts, a crucial step supporting cell migration during regenerative tissue repair. During coacervation, a switch from an endothermic to an exothermic, heat-generating process occurs, reflecting a shift from an entropically- to an enthalpically-driven thermodynamic reaction. In addition, mechanical forces cause the appearance of turbulent flows and vortices during liquid-liquid phase separation. These mechanical forces orient the cellular and mineralic (hydroxyapatite crystallite) components, as shown using mineralizing SaOS-2 cells as a model. Conclusion: Here we introduce the energetic triad: metabolic energy (ATP), thermal energy and mechanical energy as a novel theranostic biomarker, which contributes essentially to a successful application of polyP for regeneration processes.
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Affiliation(s)
- Werner E G Müller
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, 55128 Mainz, GERMANY
| | - Hadrian Schepler
- Department of Dermatology, University Medical Center of the Johannes Gutenberg University, Langenbeckstraße 1, 55131 Mainz, GERMANY
| | - Meik Neufurth
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, 55128 Mainz, GERMANY
| | - Rita Dobmeyer
- Galenus GH AG, Rainstrasse 7, 6052 Hergiswil, Switzerland
| | - Renato Batel
- Faculty of Natural Sciences, Juraj Dobrila University, Zagrebačka 30, 52100 Pula, Croatia
| | - Heinz C Schröder
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, 55128 Mainz, GERMANY
| | - Xiaohong Wang
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, 55128 Mainz, GERMANY
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Soto CA, Lesch ML, Becker JL, Sharipol A, Khan A, Schafer XL, Becker MW, Munger JC, Frisch BJ. The Lactate Receptor GPR81 is a Mechanism of Leukemia-Associated Macrophage Polarization in the Bone Marrow Microenvironment. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.11.13.566874. [PMID: 39185193 PMCID: PMC11343108 DOI: 10.1101/2023.11.13.566874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 08/27/2024]
Abstract
Interactions between acute myeloid leukemia (AML) and the bone marrow microenvironment (BMME) are critical to leukemia progression and chemoresistance. Altered metabolite levels in the tumor microenvironment contribute to immunosuppression in solid tumors, while this has not been studied yet in the leukemic BMME. Metabolomics of AML patient bone marrow serum detected elevated metabolites, including lactate, compared to age- and sex-matched controls. Excess lactate has been implicated in solid tumors for inducing suppressive tumor-associated macrophages (TAMs) and correlates with poor prognosis. We describe the role of lactate in the polarization of leukemia-associated macrophages (LAMs) using a murine model of blast crisis chronic myelogenous leukemia (bcCML) and mice genetically lacking the lactate receptor GPR81. LAMs were CD206hi and suppressive in transcriptomics and cytokine profiling. Yet, LAMs had a largely unique expression profile from other types of TAMs. We demonstrate GPR81 signaling as a mechanism of both LAM polarization and the direct support of leukemia cell growth and self-repopulation. Furthermore, LAMs and elevated lactate diminished the function of hematopoietic progenitors and stromal support, while knockout of GPR81 had modest protective effects on the hematopoietic system. We report microenvironmental lactate as a critical driver of AML-induced immunosuppression and leukemic progression, thus identifying GPR81 signaling as an exciting and novel therapeutic target for treating this devastating disease.
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Affiliation(s)
- Celia A. Soto
- Department of Pathology and Laboratory Medicine, University of Rochester School of Medicine, Rochester, NY, USA
- Wilmot Cancer Institute, University of Rochester Medical Center, Rochester, NY, USA
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY, USA
| | - Maggie L. Lesch
- Wilmot Cancer Institute, University of Rochester Medical Center, Rochester, NY, USA
- Department of Microbiology and Immunology, University of Rochester School of Medicine, Rochester, NY, USA
| | - Jennifer L. Becker
- Genomics Research Center, University of Rochester Medical Center, Rochester, NY, USA
| | - Azmeer Sharipol
- Wilmot Cancer Institute, University of Rochester Medical Center, Rochester, NY, USA
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY, USA
- Department of Biomedical Engineering, University of Rochester School of Medicine, Rochester, NY, USA
| | - Amal Khan
- Wilmot Cancer Institute, University of Rochester Medical Center, Rochester, NY, USA
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY, USA
- Department of Microbiology and Immunology, University of Rochester School of Medicine, Rochester, NY, USA
| | - Xenia L. Schafer
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine, Rochester, NY, USA
| | - Michael W. Becker
- Wilmot Cancer Institute, University of Rochester Medical Center, Rochester, NY, USA
- Department of Medicine, University of Rochester School of Medicine, Rochester, NY, USA
| | - Joshua C. Munger
- Department of Microbiology and Immunology, University of Rochester School of Medicine, Rochester, NY, USA
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine, Rochester, NY, USA
| | - Benjamin J. Frisch
- Department of Pathology and Laboratory Medicine, University of Rochester School of Medicine, Rochester, NY, USA
- Wilmot Cancer Institute, University of Rochester Medical Center, Rochester, NY, USA
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY, USA
- Department of Biomedical Engineering, University of Rochester School of Medicine, Rochester, NY, USA
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4
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Müller WEG, Neufurth M, Wang S, Schröder HC, Wang X. Polyphosphate Nanoparticles: Balancing Energy Requirements in Tissue Regeneration Processes. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2309528. [PMID: 38470207 DOI: 10.1002/smll.202309528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 01/29/2024] [Indexed: 03/13/2024]
Abstract
Nanoparticles of a particular, evolutionarily old inorganic polymer found across the biological kingdoms have attracted increasing interest in recent years not only because of their crucial role in metabolism but also their potential medical applicability: it is inorganic polyphosphate (polyP). This ubiquitous linear polymer is composed of 10-1000 phosphate residues linked by high-energy anhydride bonds. PolyP causes induction of gene activity, provides phosphate for bone mineralization, and serves as an energy supplier through enzymatic cleavage of its acid anhydride bonds and subsequent ATP formation. The biomedical breakthrough of polyP came with the development of a successful fabrication process, in depot form, as Ca- or Mg-polyP nanoparticles, or as the directly effective polymer, as soluble Na-polyP, for regenerative repair and healing processes, especially in tissue areas with insufficient blood supply. Physiologically, the platelets are the main vehicles for polyP nanoparticles in the circulating blood. To be biomedically active, these particles undergo coacervation. This review provides an overview of the properties of polyP and polyP nanoparticles for applications in the regeneration and repair of bone, cartilage, and skin. In addition to studies on animal models, the first successful proof-of-concept studies on humans for the healing of chronic wounds are outlined.
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Affiliation(s)
- Werner E G Müller
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, D-55128, Mainz, Germany
| | - Meik Neufurth
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, D-55128, Mainz, Germany
| | - Shunfeng Wang
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, D-55128, Mainz, Germany
| | - Heinz C Schröder
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, D-55128, Mainz, Germany
| | - Xiaohong Wang
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, D-55128, Mainz, Germany
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5
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Quarato ER, Salama NA, Calvi LM. Interplay Between Skeletal and Hematopoietic Cells in the Bone Marrow Microenvironment in Homeostasis and Aging. Curr Osteoporos Rep 2024; 22:416-432. [PMID: 38782850 DOI: 10.1007/s11914-024-00874-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/05/2024] [Indexed: 05/25/2024]
Abstract
PURPOSE OF THE REVIEW In this review, we discuss the most recent scientific advances on the reciprocal regulatory interactions between the skeletal and hematopoietic stem cell niche, focusing on immunomodulation and its interplay with the cell's mitochondrial function, and how this impacts osteoimmune health during aging and disease. RECENT FINDINGS Osteoimmunology investigates interactions between cells that make up the skeletal stem cell niche and immune system. Much work has investigated the complexity of the bone marrow microenvironment with respect to the skeletal and hematopoietic stem cells that regulate skeletal formation and immune health respectively. It has now become clear that these cellular components cooperate to maintain homeostasis and that dysfunction in their interaction can lead to aging and disease. Having a deeper, mechanistic appreciation for osteoimmune regulation will lead to better research perspective and therapeutics with the potential to improve the aging process, skeletal and hematologic regeneration, and disease targeting.
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Affiliation(s)
- Emily R Quarato
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, NY, USA.
- James P. Wilmot Cancer Institute, University of Rochester Medical Center, Rochester, NY, USA.
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY, USA.
| | - Noah A Salama
- James P. Wilmot Cancer Institute, University of Rochester Medical Center, Rochester, NY, USA.
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY, USA.
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY, USA.
| | - Laura M Calvi
- James P. Wilmot Cancer Institute, University of Rochester Medical Center, Rochester, NY, USA.
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY, USA.
- Department of Medicine, University of Rochester Medical Center, Rochester, NY, USA.
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Khan MP, Sabini E, Beigel K, Lanzolla G, Laslow B, Wang D, Merceron C, Giaccia A, Long F, Taylor D, Schipani E. HIF1 activation safeguards cortical bone formation against impaired oxidative phosphorylation. JCI Insight 2024; 9:e182330. [PMID: 39088272 DOI: 10.1172/jci.insight.182330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Accepted: 07/25/2024] [Indexed: 08/03/2024] Open
Abstract
Energy metabolism, through pathways such as oxidative phosphorylation (OxPhos) and glycolysis, plays a pivotal role in cellular differentiation and function. Our study investigates the impact of OxPhos disruption in cortical bone development by deleting mitochondrial transcription factor A (TFAM). TFAM controls OxPhos by regulating the transcription of mitochondrial genes. The cortical bone, constituting the long bones' rigid shell, is sheathed by the periosteum, a connective tissue layer populated with skeletal progenitors that spawn osteoblasts, the bone-forming cells. TFAM-deficient mice presented with thinner cortical bone, spontaneous midshaft fractures, and compromised periosteal cell bioenergetics, characterized by reduced ATP levels. Additionally, they exhibited an enlarged periosteal progenitor cell pool with impaired osteoblast differentiation. Increasing hypoxia-inducible factor 1a (HIF1) activity within periosteal cells substantially mitigated the detrimental effects induced by TFAM deletion. HIF1 is known to promote glycolysis in all cell types. Our findings underscore the indispensability of OxPhos for the proper accrual of cortical bone mass and indicate a compensatory mechanism between OxPhos and glycolysis in periosteal cells. The study opens new avenues for understanding the relationship between energy metabolism and skeletal health and suggests that modulating bioenergetic pathways may provide a therapeutic avenue for conditions characterized by bone fragility.
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Affiliation(s)
- Mohd P Khan
- Department of Orthopaedic Surgery, University of Pennsylvania, Perelman School of Medicine, Philadelphia, Pennsylvania, USA
- Department of Orthopaedic Surgery, School of Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Elena Sabini
- Department of Orthopaedic Surgery, University of Pennsylvania, Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Katherine Beigel
- Department of Biomedical and Health Informatics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Giulia Lanzolla
- Department of Orthopaedic Surgery, University of Pennsylvania, Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Brittany Laslow
- Department of Orthopaedic Surgery, University of Pennsylvania, Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Dian Wang
- Department of Orthopaedic Surgery, University of Pennsylvania, Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Christophe Merceron
- Department of Orthopaedic Surgery, School of Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Amato Giaccia
- Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Fanxin Long
- Department of Orthopaedic Surgery, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Deanne Taylor
- Department of Biomedical and Health Informatics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Ernestina Schipani
- Department of Orthopaedic Surgery, University of Pennsylvania, Perelman School of Medicine, Philadelphia, Pennsylvania, USA
- Department of Orthopaedic Surgery, School of Medicine, University of Michigan, Ann Arbor, Michigan, USA
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7
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Baroi S, Czernik PJ, Khan MP, Letson J, Crowe E, Chougule A, Griffin PR, Rosen CJ, Lecka-Czernik B. PPARG in osteocytes controls cell bioenergetics and systemic energy metabolism independently of sclerostin levels in circulation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.04.588029. [PMID: 38645043 PMCID: PMC11030235 DOI: 10.1101/2024.04.04.588029] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/23/2024]
Abstract
Objective The skeleton is one of the largest organs in the body, wherein metabolism is integrated with systemic energy metabolism. However, the bioenergetic programming of osteocytes, the most abundant bone cells coordinating bone metabolism, is not well defined. Here, using a mouse model with partial penetration of an osteocyte-specific PPARG deletion, we demonstrate that PPARG controls osteocyte bioenergetics and their contribution to systemic energy metabolism independently of circulating sclerostin levels. Methods In vivo and in vitro models of osteocyte-specific PPARG deletion, i.e. Dmp 1 Cre Pparγ flfl male and female mice (γOT KO ) and MLO-Y4 osteocyte-like cells with either siRNA-silenced or CRISPR/Cas9-edited Pparγ . As applicable, the models were analyzed for levels of energy metabolism, glucose metabolism, and metabolic profile of extramedullary adipose tissue, as well as the osteocyte transcriptome, mitochondrial function, bioenergetics, insulin signaling, and oxidative stress. Results Circulating sclerostin levels of γOT KO male and female mice were not different from control mice. Male γOT KO mice exhibited a high energy phenotype characterized by increased respiration, heat production, locomotion and food intake. This high energy phenotype in males did not correlate with "beiging" of peripheral adipose depots. However, both sexes showed a trend for reduced fat mass and apparent insulin resistance without changes in glucose tolerance, which correlated with decreased osteocytic responsiveness to insulin measured by AKT activation. The transcriptome of osteocytes isolated from γOT KO males suggested profound changes in cellular metabolism, fuel transport and usage, mitochondria dysfunction, insulin signaling and increased oxidative stress. In MLO-Y4 osteocytes, PPARG deficiency correlated with highly active mitochondria, increased ATP production, shifts in fuel utilization, and accumulation of reactive oxygen species (ROS). Conclusions PPARG in male osteocytes acts as a molecular break on mitochondrial function, and protection against oxidative stress and ROS accumulation. It also regulates osteocyte insulin signaling and fuel usage to produce energy. These data provide insight into the connection between osteocyte bioenergetics and their sex-specific contribution to the balance of systemic energy metabolism. These findings support the concept that the skeleton controls systemic energy expenditure via osteocyte metabolism. Highlights Osteocytes function as a body energostat via their bioenergeticsPPARG protein acts as a "molecular break" of osteocyte mitochondrial activityPPARG deficiency activates TCA cycle, oxidative stress and ROS accumulationPPARG controls osteocyte insulin signaling and fuel utilization.
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Morfin C, Sebastian A, Wilson SP, Amiri B, Murugesh DK, Hum NR, Christiansen BA, Loots GG. Mef2c regulates bone mass through Sost-dependent and -independent mechanisms. Bone 2024; 179:116976. [PMID: 38042445 DOI: 10.1016/j.bone.2023.116976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 11/16/2023] [Accepted: 11/17/2023] [Indexed: 12/04/2023]
Abstract
Mef2c is a transcription factor that mediates key cellular behaviors that promote endochondral ossification and bone formation. Previously, Mef2c has been shown to regulate Sost transcription via its osteocyte-specific enhancer, ECR5, and conditional deletions of Mef2cfl/fl with either Col1-Cre or Dmp1-Cre produced generalized high bone mass (HBM) consistent with Van Buchem Disease phenotypes. However, Sost-/-; Mef2cfl/fl; Dmp1-Cre mice produced a significantly higher bone mass phenotype that Sost-/- alone suggesting that Mef2c modulates bone mass through additional mechanisms, independent of Sost. To identify new Mef2c transcriptional targets important in bone metabolism, we profiled gene expression by single-cell RNA sequencing in subpopulations of cells isolated from Mef2cfl/fl; Dmp1-Cre and Mef2cfl/fl; Bglap-Cre femurs, both strains exhibiting similar high bone mass phenotypes. However, we found Mef2cfl/fl; Bglap-Cre to also display a growth plate defect characterized by an expansion of several osteoprogenitor subpopulations. Differential gene expression analysis identified a total of 96 up- and 2434 down- regulated genes in Mef2cfl/fl; Bglap-Cre and 176 up- and 1041 down- regulated genes in Mef2cfl/fl; Dmp1-Cre bone cell subpopulations compared to wildtype mice. Mef2c deletion affected the transcriptomes across several cell types including mesenchymal progenitors (MP), osteoprogenitors (OSP), osteoblast (OB), and osteocyte (OCY) subpopulations. Several energy metabolism genes such as Uqcrb, Ndufv2, Ndufs3, Ndufa13, Ndufb9, Ndufb5, Cox6a1, Cox5a, Atp5o, Atp5g2, Atp5b, Atp5 were significantly down regulated in Mef2c-deficient OBs and OCYs, in both strains. Binding motif analysis of promoter regions of differentially expressed genes identified Mef2c binding in Bone Sialoprotein (BSP/Ibsp), a gene known to cause increased trabecular BV/TV in the femurs of Ibsp-/- mice. Immunohistochemical analysis confirmed the absence of Ibsp protein in OBs and OCYs. These findings suggests that the HBM in Sost-/-; Mef2cfl/fl; Dmp1-Cre is caused by a multitude of transcriptional changes in genes that regulate bone formation, two of which are Sost and Ibsp.
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Affiliation(s)
- Cesar Morfin
- School of Natural Sciences, University of California, Merced, CA, United States; Physical and Life Sciences Directorate, Lawrence Livermore, National Laboratories, Livermore, CA, United States; Department of Orthopaedic Surgery, University of California Davis Health, Sacramento, CA, United States
| | - Aimy Sebastian
- Physical and Life Sciences Directorate, Lawrence Livermore, National Laboratories, Livermore, CA, United States
| | - Stephen P Wilson
- Physical and Life Sciences Directorate, Lawrence Livermore, National Laboratories, Livermore, CA, United States
| | - Beheshta Amiri
- Physical and Life Sciences Directorate, Lawrence Livermore, National Laboratories, Livermore, CA, United States
| | - Deepa K Murugesh
- Physical and Life Sciences Directorate, Lawrence Livermore, National Laboratories, Livermore, CA, United States
| | - Nicholas R Hum
- Physical and Life Sciences Directorate, Lawrence Livermore, National Laboratories, Livermore, CA, United States
| | - Blaine A Christiansen
- Department of Orthopaedic Surgery, University of California Davis Health, Sacramento, CA, United States
| | - Gabriela G Loots
- School of Natural Sciences, University of California, Merced, CA, United States; Physical and Life Sciences Directorate, Lawrence Livermore, National Laboratories, Livermore, CA, United States; Department of Orthopaedic Surgery, University of California Davis Health, Sacramento, CA, United States.
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Seeger DR, Schofield B, Besch D, Golovko SA, Kotha P, Parmer M, Solaymani-Mohammadi S, Golovko MY. Exogenous oxygen is required for prostanoid induction under brain ischemia as evidence for a novel regulatory mechanism. J Lipid Res 2023; 64:100452. [PMID: 37783389 PMCID: PMC10630775 DOI: 10.1016/j.jlr.2023.100452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 09/25/2023] [Accepted: 09/28/2023] [Indexed: 10/04/2023] Open
Abstract
Previously, we and others reported a rapid and dramatic increase in brain prostanoids (PG), including prostaglandins, prostacyclins, and thromboxanes, under ischemia that is traditionally explained through the activation of esterified arachidonic acid (20:4n6) release by phospholipases as a substrate for cyclooxygenases (COX). However, the availability of another required COX substrate, oxygen, has not been considered in this mechanism. To address this mechanism for PG upregulation through oxygen availability, we analyzed mouse brain PG, free 20:4n6, and oxygen levels at different time points after ischemic onset using head-focused microwave irradiation (MW) to inactivate enzymes in situ before craniotomy. The oxygen half-life in the ischemic brain was 5.32 ± 0.45 s and dropped to undetectable levels within 12 s of ischemia onset, while there were no significant free 20:4n6 or PG changes at 30 s of ischemia. Furthermore, there was no significant PG increase at 2 and 10 min after ischemia onset compared to basal levels, while free 20:4n6 was increased ∼50 and ∼100 fold, respectively. However, PG increased ∼30-fold when ischemia was followed by craniotomy of nonMW tissue that provided oxygen for active enzymes. Moreover, craniotomy performed under anoxic conditions without MW did not result in PG induction, while exposure of these brains to atmospheric oxygen significantly induced PG. Our results indicate, for the first time, that oxygen availability is another important regulatory factor for PG production under ischemia. Further studies are required to investigate the physiological role of COX/PG regulation through tissue oxygen concentration.
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Affiliation(s)
- Drew R Seeger
- Department of Biomedical Sciences, School of Medicine and Health Science, University of North Dakota, Grand Forks, ND, USA
| | - Brennon Schofield
- Department of Biomedical Sciences, School of Medicine and Health Science, University of North Dakota, Grand Forks, ND, USA
| | - Derek Besch
- Department of Biomedical Sciences, School of Medicine and Health Science, University of North Dakota, Grand Forks, ND, USA
| | - Svetlana A Golovko
- Department of Biomedical Sciences, School of Medicine and Health Science, University of North Dakota, Grand Forks, ND, USA
| | - Peddanna Kotha
- Department of Biomedical Sciences, School of Medicine and Health Science, University of North Dakota, Grand Forks, ND, USA
| | - Meredith Parmer
- Department of Biomedical Sciences, School of Medicine and Health Science, University of North Dakota, Grand Forks, ND, USA
| | - Shahram Solaymani-Mohammadi
- Department of Biomedical Sciences, School of Medicine and Health Science, University of North Dakota, Grand Forks, ND, USA
| | - Mikhail Y Golovko
- Department of Biomedical Sciences, School of Medicine and Health Science, University of North Dakota, Grand Forks, ND, USA.
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Hutson MJ, O'Donnell E, Brooke-Wavell K, James LJ, Raleigh CJ, Carson BP, Sale C, Blagrove RC. High-impact jumping mitigates the short-term effects of low energy availability on bone resorption but not formation in regularly menstruating females: A randomized control trial. Scand J Med Sci Sports 2023; 33:1690-1702. [PMID: 37365858 DOI: 10.1111/sms.14437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 06/14/2023] [Accepted: 06/15/2023] [Indexed: 06/28/2023]
Abstract
Low energy availability (LEA) is prevalent in active individuals and negatively impacts bone turnover in young females. High-impact exercise can promote bone health in an energy efficient manner and may benefit bone during periods of LEA. Nineteen regularly menstruating females (aged 18-31 years) participated in two three-day conditions providing 15 (LEA) and 45 kcals kg fat-free mass-1 day-1 (BAL) of energy availability, each beginning 3 ± 1 days following the self-reported onset of menses. Participants either did (LEA+J, n = 10) or did not (LEA, n = 9) perform 20 high-impact jumps twice per day during LEA, with P1NP, β-CTx (circulating biomarkers of bone formation and resorption, respectively) and other markers of LEA measured pre and post in a resting and fasted state. Data are presented as estimated marginal mean ± 95% CI. P1NP was significantly reduced in LEA (71.8 ± 6.1-60.4 ± 6.2 ng mL-1 , p < 0.001, d = 2.36) and LEA+J (93.9 ± 13.4-85.2 ± 12.3 ng mL-1 , p < 0.001, d = 1.66), and these effects were not significantly different (time by condition interaction: p = 0.269). β-CTx was significantly increased in LEA (0.39 ± 0.09-0.46 ± 0.10 ng mL-1 , p = 0.002, d = 1.11) but not in LEA+J (0.65 ± 0.08-0.65 ± 0.08 ng mL-1 , p > 0.999, d = 0.19), and these effects were significantly different (time by condition interaction: p = 0.007). Morning basal bone formation rate is reduced following 3 days LEA, induced via dietary restriction, with or without high-impact jumping in regularly menstruating young females. However, high-impact jumping can prevent an increase in morning basal bone resorption rate and may benefit long-term bone health in individuals repeatedly exposed to such bouts.
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Affiliation(s)
- Mark J Hutson
- School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
- School of Sport, Faculty of Life and Health Sciences, Ulster University, Coleraine, UK
| | - Emma O'Donnell
- School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
| | | | - Lewis J James
- School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
| | - Conor J Raleigh
- Department of Physical Education & Sport Sciences, University of Limerick, Limerick, Ireland
| | - Brian P Carson
- Department of Physical Education & Sport Sciences, University of Limerick, Limerick, Ireland
| | - Craig Sale
- Department of Sport and Exercise Sciences, Institute of Sport, Manchester Metropolitan University, Manchester, UK
| | - Richard C Blagrove
- School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
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11
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Akhmetshina A, Kratky D, Rendina-Ruedy E. Influence of Cholesterol on the Regulation of Osteoblast Function. Metabolites 2023; 13:metabo13040578. [PMID: 37110236 PMCID: PMC10143138 DOI: 10.3390/metabo13040578] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 04/11/2023] [Accepted: 04/19/2023] [Indexed: 04/29/2023] Open
Abstract
Bone is a dynamic tissue composed of cells, an extracellular matrix, and mineralized portion. Osteoblasts are responsible for proper bone formation and remodeling, and function. These processes are endergonic and require cellular energy in the form of adenosine triphosphate (ATP), which is derived from various sources such as glucose, fatty acids, and amino acids. However, other lipids such as cholesterol have also been found to play a critical role in bone homeostasis and can also contribute to the overall bioenergetic capacity of osteoblasts. In addition, several epidemiological studies have found a link between elevated cholesterol, cardiovascular disease, an enhanced risk of osteoporosis, and increased bone metastasis in cancer patients. This review focuses on how cholesterol, its derivatives, and cholesterol-lowering medications (statins) regulate osteoblast function and bone formation. It also highlights the molecular mechanisms underlying the cholesterol-osteoblast crosstalk.
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Affiliation(s)
- Alena Akhmetshina
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria
- Department of Medicine, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Dagmar Kratky
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria
- BioTechMed-Graz, 8010 Graz, Austria
| | - Elizabeth Rendina-Ruedy
- Department of Medicine, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37235, USA
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12
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Sautchuk R, Yu C, McArthur M, Massie C, Brookes PS, Porter GA, Awad H, Eliseev RA. Role of the Mitochondrial Permeability Transition in Bone Metabolism and Aging. J Bone Miner Res 2023; 38:522-540. [PMID: 36779737 PMCID: PMC10101909 DOI: 10.1002/jbmr.4787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 02/02/2023] [Accepted: 02/07/2023] [Indexed: 02/14/2023]
Abstract
The mitochondrial permeability transition pore (MPTP) and its positive regulator, cyclophilin D (CypD), play important pathophysiological roles in aging. In bone tissue, higher CypD expression and pore activity are found in aging; however, a causal relationship between CypD/MPTP and bone degeneration needs to be established. We previously reported that CypD expression and MPTP activity are downregulated during osteoblast (OB) differentiation and that manipulations in CypD expression affect OB differentiation and function. Using a newly developed OB-specific CypD/MPTP gain-of-function (GOF) mouse model, we here present evidence that overexpression of a constitutively active K166Q mutant of CypD (caCypD) impairs OB energy metabolism and function, and bone morphological and biomechanical parameters. Specifically, in a spatial-dependent and sex-dependent manner, OB-specific CypD GOF led to a decrease in oxidative phosphorylation (OxPhos) levels, higher oxidative stress, and general metabolic adaptations coincident with the decreased bone organic matrix content in long bones. Interestingly, accelerated bone degeneration was present in vertebral bones regardless of sex. Overall, our work confirms CypD/MPTP overactivation as an important pathophysiological mechanism leading to bone degeneration and fragility in aging. © 2023 American Society for Bone and Mineral Research (ASBMR).
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Affiliation(s)
- Rubens Sautchuk
- Center for Musculoskeletal ResearchUniversity of Rochester, Rochester, NY, USA
| | - Chen Yu
- Center for Musculoskeletal ResearchUniversity of Rochester, Rochester, NY, USA
| | - Matthew McArthur
- Center for Musculoskeletal ResearchUniversity of Rochester, Rochester, NY, USA
| | - Christine Massie
- Center for Musculoskeletal ResearchUniversity of Rochester, Rochester, NY, USA
- Department of Biomedical Engineering, University of Rochester, Rochester, NY, USA
| | - Paul S Brookes
- Department of Anesthesiology and Perioperative Medicine, University of Rochester, Rochester, NY, USA
- Department of Pharmacology & Physiology, University of Rochester, Rochester, NY, USA
| | - George A Porter
- Department of Pediatrics, Division of Cardiology, University of Rochester, Rochester, NY, USA
| | - Hani Awad
- Center for Musculoskeletal ResearchUniversity of Rochester, Rochester, NY, USA
- Department of Biomedical Engineering, University of Rochester, Rochester, NY, USA
| | - Roman A Eliseev
- Center for Musculoskeletal ResearchUniversity of Rochester, Rochester, NY, USA
- Department of Pharmacology & Physiology, University of Rochester, Rochester, NY, USA
- Department of Pathology, University of Rochester, Rochester, NY, USA
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13
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Chaudhary S, Ghosal D, Tripathi P, Kumar S. Cellular metabolism: a link connecting cellular behaviour with the physiochemical properties of biomaterials for bone tissue engineering. Biomater Sci 2023; 11:2277-2291. [PMID: 36748852 DOI: 10.1039/d2bm01410f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Biomaterial properties, such as surface roughness, morphology, stiffness, conductivity, and chemistry, significantly influence a cell's ability to sense and adhere to its surface and regulate cell functioning. Understanding how biomaterial properties govern changes in cellular function is one of the fundamental goals of tissue engineering. Still, no generalized rule is established to predict cellular processes (adhesion, spreading, growth and differentiation) on biomaterial surfaces. A few studies have highlighted that cells sense biomaterial properties at multiple length scales and regulate various intracellular biochemical processes like cytoskeleton organization, gene regulation, and receptor expression to influence cell function. However, recent studies have found cellular metabolism as another critical aspect of cellular processes that regulate cell behavior, co-relating metabolism to cellular functions like adhesion, proliferation, and differentiation. Now researchers have started to uncover previously overlooked factors on how biomaterial properties govern changes in cellular functions mediated through metabolism. This review highlights how different physiochemical properties of scaffolds designed from different biomaterials influence cell metabolism. The review also discusses the role of metabolism change in cellular functions and cell behavior in the context of bone tissue engineering. It also emphasizes the importance of cell metabolism as a missing link between the cellular behavior and physicochemical properties of scaffolds and serves as a guiding principle for designing scaffolds for tissue engineering.
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Affiliation(s)
- Shivani Chaudhary
- Centre for Biomedical Engineering, Indian Institute of Technology Delhi, New Delhi 110016, India.
| | - Doyel Ghosal
- Centre for Biomedical Engineering, Indian Institute of Technology Delhi, New Delhi 110016, India.
| | - Pravesh Tripathi
- Centre for Biomedical Engineering, Indian Institute of Technology Delhi, New Delhi 110016, India.
| | - Sachin Kumar
- Centre for Biomedical Engineering, Indian Institute of Technology Delhi, New Delhi 110016, India. .,Department of Biomedical Engineering, All India Institute of Medical Sciences, New Delhi 110029, India
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14
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Yang YY, Luo HH, Deng YX, Yao XT, Zhang J, Su YX, He BC. Pyruvate dehydrogenase kinase 4 promotes osteoblastic potential of BMP9 by boosting Wnt/β-catenin signaling in mesenchymal stem cells. Int J Biochem Cell Biol 2023; 154:106341. [PMID: 36442735 DOI: 10.1016/j.biocel.2022.106341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2022] [Revised: 09/14/2022] [Accepted: 11/23/2022] [Indexed: 11/26/2022]
Abstract
Bone morphogenetic protein 9 (BMP9) is an effective osteogenic factor and a promising candidate for bone tissue engineering. The osteoblastic potential of BMP9 needs to be further increased to overcome its shortcomings. However, the details of how BMP9 triggers osteogenic differentiation in mesenchymal stem cells (MSCs) are unclear. In this study, we used real-time PCR, western blot, histochemical staining, mouse ectopic bone formation model, immunofluorescence, immunoprecipitation, and chromatin immunoprecipitation to investigate the role of pyruvate dehydrogenase kinase 4 (PDK4) in BMP9-induced osteogenic differentiation of C3H10T1/2 cells, as well as the underlying mechanism. We found that PDK4 was upregulated by BMP9 in C3H10T1/2 cells. BMP9-induced osteogenic markers and bone mass were increased by PDK4 overexpression, but decreased by PDK4 silencing. β-catenin protein level was increased by BMP9, which was enhanced by PDK overexpression and decreased by PDK4 silencing. BMP9-induced osteogenic markers were reduced by PDK4 silencing, which was almost reversed by β-catenin overexpression. PDK4 increased the BMP9-induced osteogenic markers, which was almost eliminated by β-catenin silencing. Sclerostin was mildly decreased by BMP9 or PDK4, and significantly decreased by combined BMP9 and PDK4. In contrast, sclerostin increased significantly when BMP9 was combined with PDK4 silencing. BMP9-induced p-SMAD1/5/9 was increased by PDK4 overexpression, but was reduced by PDK4 silencing. PDK4 interacts with p-SMAD1/5/9 and regulates the sclerostin promoter. These findings suggest that PDK4 can increase the osteogenic potential of BMP9 by enhancing Wnt/β-catenin signaling via the downregulation of sclerostin. PDK4 may be an effective target to strengthen BMP9-induced osteogenesis.
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Affiliation(s)
- Yuan-Yuan Yang
- Department of Pharmacology, School of Pharmacy, Chongqing Medical University, Chongqing 400016, People's Republic of China; Key Laboratory of Biochemistry and Molecular Pharmacology of Chongqing, Chongqing Medical University, Chongqing 400016, People's Republic of China
| | - Hong-Hong Luo
- Department of Pharmacology, School of Pharmacy, Chongqing Medical University, Chongqing 400016, People's Republic of China; Key Laboratory of Biochemistry and Molecular Pharmacology of Chongqing, Chongqing Medical University, Chongqing 400016, People's Republic of China
| | - Yi-Xuan Deng
- Department of Pharmacology, School of Pharmacy, Chongqing Medical University, Chongqing 400016, People's Republic of China; Key Laboratory of Biochemistry and Molecular Pharmacology of Chongqing, Chongqing Medical University, Chongqing 400016, People's Republic of China
| | - Xin-Tong Yao
- Department of Pharmacology, School of Pharmacy, Chongqing Medical University, Chongqing 400016, People's Republic of China; Key Laboratory of Biochemistry and Molecular Pharmacology of Chongqing, Chongqing Medical University, Chongqing 400016, People's Republic of China
| | - Jie Zhang
- Department of Pharmacology, School of Pharmacy, Chongqing Medical University, Chongqing 400016, People's Republic of China; Key Laboratory of Biochemistry and Molecular Pharmacology of Chongqing, Chongqing Medical University, Chongqing 400016, People's Republic of China
| | - Yu-Xi Su
- Department of Orthopedics, Children's Hospital of Chongqing Medical University, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing 400014, People's Republic of China
| | - Bai-Cheng He
- Department of Pharmacology, School of Pharmacy, Chongqing Medical University, Chongqing 400016, People's Republic of China; Key Laboratory of Biochemistry and Molecular Pharmacology of Chongqing, Chongqing Medical University, Chongqing 400016, People's Republic of China.
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15
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Liu XH, Pan JP, Bauman WA, Cardozo C. Myostatin inhibits insulin-like growth factor 1-dependent citrate secretion and osteogenesis via nicotinamide adenine dinucleotide phosphate oxidase-4 in a mouse mesenchymal stem cell line. Ann N Y Acad Sci 2022; 1517:203-212. [PMID: 36072988 DOI: 10.1111/nyas.14894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Citrate is an indispensable component of bone. Reduced levels of citrate in bone and serum are reported in the elderly and in osteoporosis patients. Myostatin (Mstn) is implicated in skeletal homeostasis, but its effects on osteogenesis remain incompletely understood. Nox4 has critical roles in bone homeostasis. TGF-β/Mstn-associated Smad2/3 signaling has been linked to Nox4 expression. Insulin-like growth factor (IGF-1) has been shown to counteract many regulatory effects of Mstn. However, the crosstalk among Mstn, IGF-1, and Nox4 is not well understood; the interactive effects of those factors on citrate secretion, osteogenic differentiation, and bone remodeling remain unclear. In this study, we demonstrated that osteogenic differentiation induced an IGF-1-dependent upregulation of citrate secretion that was suppressed by Mstn. Inhibition of Nox4 prevented Mstn-induced reduction of citrate secretion. In addition, Mstn reduced bone nodule formation; these changes were prevented by Nox4 inhibition. Moreover, Mstn increased the ratio of RANKL to OPG mRNAs to favor osteoclast activation. These results indicate that Mstn negatively regulates osteogenesis by increasing levels of Nox4, which reduced IGF-1 expression, citrate secretion, and bone mineralization while also altering the RANKL to OPG ratio. These findings provide new and highly relevant insights into the osseous effects of myostatin.
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Affiliation(s)
- Xin-Hua Liu
- National Center for the Medical Consequences of Spinal Cord Injury, James J. Peter VA Medical Center, Bronx, New York, USA
- Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Jiang Ping Pan
- National Center for the Medical Consequences of Spinal Cord Injury, James J. Peter VA Medical Center, Bronx, New York, USA
| | - William A Bauman
- National Center for the Medical Consequences of Spinal Cord Injury, James J. Peter VA Medical Center, Bronx, New York, USA
- Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Medical Service, James J. Peter VA Medical Center, Bronx, New York, USA
- Department of Rehabilitation Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Bone Program, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Christopher Cardozo
- National Center for the Medical Consequences of Spinal Cord Injury, James J. Peter VA Medical Center, Bronx, New York, USA
- Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Medical Service, James J. Peter VA Medical Center, Bronx, New York, USA
- Department of Rehabilitation Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Bone Program, Icahn School of Medicine at Mount Sinai, New York, New York, USA
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