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Stavnichuk M, Komarova SV. Megakaryocyte-driven changes in bone health: lessons from mouse models of myelofibrosis and related disorders. Am J Physiol Cell Physiol 2021; 322:C177-C184. [PMID: 34910601 DOI: 10.1152/ajpcell.00328.2021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Over the years, numerous studies demonstrated reciprocal communications between processes of bone marrow hematopoiesis and bone remodeling. Megakaryocytes, rare bone marrow cells responsible for platelet production, were demonstrated to be involved in bone homeostasis. Myelofibrosis, characterized by an increase in pleomorphic megakaryocytes in the bone marrow, commonly leads to the development of osteosclerosis. In vivo, an increase in megakaryocyte number was shown to result in osteosclerosis in GATA-1low, NF-E2-/-, TPOhigh, Mpllf/f;PF4cre, Lnk-/-, Mpig6b-/-, Mpig6bfl/fl;Gp1ba-Cr+/KI, Pt-vWD mouse models. In vitro, megakaryocytes stimulate osteoblast proliferation and have variable effects on osteoclast proliferation and activity through soluble factors and direct cell-cell communications. Intriguingly, new studies revealed that the ability of megakaryocytes to communicate with bone cells is affected by the age and sex of animals. This mini-review summarises changes seen in bone architecture and bone cell function in mouse models with an elevated number of megakaryocytes and the effects megakaryocytes have on osteoblasts and osteoclasts in vitro, and discusses potential molecular players that can mediate these effects.
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Affiliation(s)
- Mariya Stavnichuk
- Shriners Hospital for Children - Canada, Montreal, Quebec, Canada.,Faculty of Dentistry, McGill University, Montreal, Quebec, Canada
| | - Svetlana V Komarova
- Shriners Hospital for Children - Canada, Montreal, Quebec, Canada.,Faculty of Dentistry, McGill University, Montreal, Quebec, Canada
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2
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Myeloproliferative Disorders and its Effect on Bone Homeostasis: The Role of Megakaryocytes. Blood 2021; 139:3127-3137. [PMID: 34428274 DOI: 10.1182/blood.2021011480] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 08/11/2021] [Indexed: 11/20/2022] Open
Abstract
Myeloproliferative Neoplasms (MPNs) are a heterogeneous group of chronic hematological diseases that arise from the clonal expansion of abnormal hematopoietic stem cells, of which Polycythemia Vera (PV), Essential Thrombocythemia (ET), and Primary Myelofibrosis (PMF) have been extensively reviewed in context of clonal expansion, fibrosis and other phenotypes. Here, we review current knowledge on the influence of different forms of MPN on bone health. Studies implicated various degrees of effect of different forms of MPN on bone density, and on osteoblast proliferation and differentiation, using murine models and human data. The majority of studies show that bone volume is generally increased in PMF patients, whereas it is slightly decreased or not altered in ET and PV patients, although possible differences between male and female phenotypes were not fully explored in most MPN forms. Osteosclerosis seen in PMF patients is a serious complication that can lead to bone marrow failure, and the loss of bone reported in some ET and PV patients can lead to osteoporotic fractures. Some MPN forms are associated with increased number of megakaryocytes (MKs), and several of the MK-associated factors in MPN are known to affect bone development. Here, we review known mechanisms involved in these processes, with focus on the role of MKs and secreted factors. Understanding MPN-associated changes in bone health could improve early intervention and treatment of this side effect of the pathology.
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3
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Zamarioli A, Campbell ZR, Maupin KA, Childress PJ, Ximenez JPB, Adam G, Chakraborty N, Gautam A, Hammamieh R, Kacena MA. Analysis of the effects of spaceflight and local administration of thrombopoietin to a femoral defect injury on distal skeletal sites. NPJ Microgravity 2021; 7:12. [PMID: 33772025 PMCID: PMC7997973 DOI: 10.1038/s41526-021-00140-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 02/26/2021] [Indexed: 02/01/2023] Open
Abstract
With increased human presence in space, bone loss and fractures will occur. Thrombopoietin (TPO) is a recently patented bone healing agent. Here, we investigated the systemic effects of TPO on mice subjected to spaceflight and sustaining a bone fracture. Forty, 9-week-old, male, C57BL/6 J were divided into 4 groups: (1) Saline+Earth; (2) TPO + Earth; (3) Saline+Flight; and (4) TPO + Flight (n = 10/group). Saline- and TPO-treated mice underwent a femoral defect surgery, and 20 mice were housed in space ("Flight") and 20 mice on Earth for approximately 4 weeks. With the exception of the calvarium and incisor, positive changes were observed in TPO-treated, spaceflight bones, suggesting TPO may improve osteogenesis in the absence of mechanical loading. Thus, TPO, may serve as a new bone healing agent, and may also improve some skeletal properties of astronauts, which might be extrapolated for patients on Earth with restraint mobilization and/or are incapable of bearing weight on their bones.
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Affiliation(s)
- Ariane Zamarioli
- grid.257413.60000 0001 2287 3919Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, IN USA ,Department of Orthopaedics and Anaesthesiology, Ribeirão Preto Medical School, Ribeirão Preto, SP Brazil
| | - Zachery R. Campbell
- grid.257413.60000 0001 2287 3919Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, IN USA ,Marian University College of Osteopathic Medicine, Indianapolis, IN USA
| | - Kevin A. Maupin
- grid.257413.60000 0001 2287 3919Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, IN USA
| | - Paul J. Childress
- grid.257413.60000 0001 2287 3919Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, IN USA
| | - Joao P. B. Ximenez
- Laboratory of Molecular Biology, Blood Center of Ribeirão Preto, Medical School, Ribeirão Pre, SP Brazil
| | - Gremah Adam
- grid.257413.60000 0001 2287 3919Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, IN USA
| | - Nabarun Chakraborty
- grid.507680.c0000 0001 2230 3166Medical Readiness Systems Biology, Walter Reed Army Institute of Research, Silver Spring, MD USA ,grid.507680.c0000 0001 2230 3166Geneva Foundation, Walter Reed Army Institute of Research, Silver Spring, MD USA
| | - Aarti Gautam
- grid.507680.c0000 0001 2230 3166Medical Readiness Systems Biology, Walter Reed Army Institute of Research, Silver Spring, MD USA
| | - Rasha Hammamieh
- grid.507680.c0000 0001 2230 3166Medical Readiness Systems Biology, Walter Reed Army Institute of Research, Silver Spring, MD USA
| | - Melissa A. Kacena
- grid.257413.60000 0001 2287 3919Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, IN USA ,grid.280828.80000 0000 9681 3540Richard L. Roudebush VA Medical Center, Indianapolis, IN USA
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Kanagasabapathy D, Blosser RJ, Maupin KA, Hong JM, Alvarez M, Ghosh J, Mohamad SF, Aguilar-Perez A, Srour EF, Kacena MA, Bruzzaniti A. Megakaryocytes promote osteoclastogenesis in aging. Aging (Albany NY) 2020; 12:15121-15133. [PMID: 32634116 PMCID: PMC7425434 DOI: 10.18632/aging.103595] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2020] [Accepted: 06/13/2020] [Indexed: 01/26/2023]
Abstract
Megakaryocytes (MKs) support bone formation by stimulating osteoblasts (OBs) and inhibiting osteoclasts (OCs). Aging results in higher bone resorption, leading to bone loss. Whereas previous studies showed the effects of aging on MK-mediated bone formation, the effects of aging on MK-mediated OC formation is poorly understood. Here we examined the effect of thrombopoietin (TPO) and MK-derived conditioned media (CM) from young (3-4 months) and aged (22-25 months) mice on OC precursors. Our findings showed that aging significantly increased OC formation in vitro. Moreover, the expression of the TPO receptor, Mpl, and circulating TPO levels were elevated in the bone marrow cavity. We previously showed that MKs from young mice secrete factors that inhibit OC differentiation. However, rather than inhibiting OC development, we found that MKs from aged mice promote OC formation. Interestingly, these age-related changes in MK functionality were only observed using female MKs, potentially implicating the sex steroid, estrogen, in signaling. Further, RANKL expression was highly elevated in aged MKs suggesting MK-derived RANKL signaling may promote osteoclastogenesis in aging. Taken together, these data suggest that modulation in TPO-Mpl expression in bone marrow and age-related changes in the MK secretome promote osteoclastogenesis to impact skeletal aging.
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Affiliation(s)
- Deepa Kanagasabapathy
- Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Rachel J Blosser
- Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Kevin A Maupin
- Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Jung Min Hong
- Department of Biomedical Sciences and Comprehensive Care, Indiana University School of Dentistry, Indianapolis, IN 46202, USA
| | - Marta Alvarez
- Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Joydeep Ghosh
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Safa F Mohamad
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Alexandra Aguilar-Perez
- Department of Biomedical Sciences and Comprehensive Care, Indiana University School of Dentistry, Indianapolis, IN 46202, USA
| | - Edward F Srour
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Melissa A Kacena
- Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Angela Bruzzaniti
- Department of Biomedical Sciences and Comprehensive Care, Indiana University School of Dentistry, Indianapolis, IN 46202, USA
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5
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Maupin KA, Himes ER, Plett AP, Chua HL, Singh P, Ghosh J, Mohamad SF, Abeysekera I, Fisher A, Sampson C, Hong JM, Childress P, Alvarez M, Srour EF, Bruzzaniti A, Pelus LM, Orschell CM, Kacena MA. Aging negatively impacts the ability of megakaryocytes to stimulate osteoblast proliferation and bone mass. Bone 2019; 127:452-459. [PMID: 31299382 PMCID: PMC6708771 DOI: 10.1016/j.bone.2019.07.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 06/15/2019] [Accepted: 07/08/2019] [Indexed: 12/11/2022]
Abstract
Osteoblast number and activity decreases with aging, contributing to the age-associated decline of bone mass, but the mechanisms underlying changes in osteoblast activity are not well understood. Here, we show that the age-associated bone loss critically depends on impairment of the ability of megakaryocytes (MKs) to support osteoblast proliferation. Co-culture of osteoblast precursors with young MKs is known to increase osteoblast proliferation and bone formation. However, co-culture of osteoblast precursors with aged MKs resulted in significantly fewer osteoblasts compared to co-culture with young MKs, and this was associated with the downregulation of transforming growth factor beta. In addition, the ability of MKs to increase bone mass was attenuated during aging as transplantation of GATA1low/low hematopoietic donor cells (which have elevated MKs/MK precursors) from young mice resulted in an increase in bone mass of recipient mice compared to transplantation of young wild-type donor cells, whereas transplantation of GATA1low/low donor cells from old mice failed to enhance bone mass in recipient mice compared to transplantation of old wild-type donor cells. These findings suggest that the preservation or restoration of the MK-mediated induction of osteoblast proliferation during aging may hold the potential to prevent age-associated bone loss and resulting fractures.
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Affiliation(s)
| | - Evan R Himes
- Indiana University School of Medicine, Indiana, USA
| | | | - Hui Lin Chua
- Indiana University School of Medicine, Indiana, USA
| | | | | | | | | | - Alexa Fisher
- Indiana University School of Medicine, Indiana, USA
| | | | - Jung-Min Hong
- Indiana University School of Dentistry, Indiana, USA
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6
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Alvarez MB, Xu L, Childress PJ, Maupin KA, Mohamad SF, Chitteti BR, Himes E, Olivos DJ, Cheng YH, Conway SJ, Srour EF, Kacena MA. Megakaryocyte and Osteoblast Interactions Modulate Bone Mass and Hematopoiesis. Stem Cells Dev 2019; 27:671-682. [PMID: 29631496 DOI: 10.1089/scd.2017.0178] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Emerging evidence demonstrates that megakaryocytes (MK) play key roles in regulating skeletal homeostasis and hematopoiesis. To test if the loss of MK negatively impacts osteoblastogenesis and hematopoiesis, we generated conditional knockout mice where Mpl, the receptor for the main MK growth factor, thrombopoietin, was deleted specifically in MK (Mplf/f;PF4cre). Unexpectedly, at 12 weeks of age, these mice exhibited a 10-fold increase in platelets, a significant expansion of hematopoietic/mesenchymal precursors, and a remarkable 20-fold increase in femoral midshaft bone volume. We then investigated whether MK support hematopoietic stem cell (HSC) function through the interaction of MK with osteoblasts (OB). LSK cells (Lin-Sca1+CD117+, enriched HSC population) were co-cultured with OB+MK for 1 week (1wk OB+MK+LSK) or OB alone (1wk OB+LSK). A significant increase in colony-forming units was observed with cells from 1wk OB+MK cultures. Competitive repopulation studies demonstrated significantly higher engraftment in mice transplanted with cells from 1wk OB+MK+LSK cultures compared to 1wk OB+LSK or LSK cultured alone for 1 week. Furthermore, single-cell expression analysis of OB cultured±MK revealed adiponectin as the most significantly upregulated MK-induced gene, which is required for optimal long-term hematopoietic reconstitution. Understanding the interactions between MK, OB, and HSC can inform the development of novel treatments to enhance both HSC recovery following myelosuppressive injuries, as well as bone loss diseases, such as osteoporosis.
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Affiliation(s)
- Marta B Alvarez
- 1 Department of Orthopaedic Surgery, Indiana University School of Medicine , Indianapolis, Indiana
| | - LinLin Xu
- 2 Department of Medicine, Indiana University School of Medicine , Indianapolis, Indiana
| | - Paul J Childress
- 1 Department of Orthopaedic Surgery, Indiana University School of Medicine , Indianapolis, Indiana
| | - Kevin A Maupin
- 1 Department of Orthopaedic Surgery, Indiana University School of Medicine , Indianapolis, Indiana
| | - Safa F Mohamad
- 2 Department of Medicine, Indiana University School of Medicine , Indianapolis, Indiana
| | | | - Evan Himes
- 1 Department of Orthopaedic Surgery, Indiana University School of Medicine , Indianapolis, Indiana
| | - David J Olivos
- 1 Department of Orthopaedic Surgery, Indiana University School of Medicine , Indianapolis, Indiana
| | - Ying-Hua Cheng
- 1 Department of Orthopaedic Surgery, Indiana University School of Medicine , Indianapolis, Indiana
| | - Simon J Conway
- 3 Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine , Indianapolis, Indiana
| | - Edward F Srour
- 2 Department of Medicine, Indiana University School of Medicine , Indianapolis, Indiana.,3 Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine , Indianapolis, Indiana
| | - Melissa A Kacena
- 1 Department of Orthopaedic Surgery, Indiana University School of Medicine , Indianapolis, Indiana
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7
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Curtis KJ, Oberman AG, Niebur GL. Effects of mechanobiological signaling in bone marrow on skeletal health. Ann N Y Acad Sci 2019; 1460:11-24. [PMID: 31508828 DOI: 10.1111/nyas.14232] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 08/09/2019] [Accepted: 08/15/2019] [Indexed: 01/27/2023]
Abstract
Bone marrow is a cellular tissue that forms within the pore space and hollow diaphysis of bones. As a tissue, its primary function is to support the hematopoietic progenitor cells that maintain the populations of both erythroid and myeloid lineage cells in the bone marrow, making it an essential element of normal mammalian physiology. However, bone's primary function is load bearing, and deformations induced by external forces are transmitted to the encapsulated marrow. Understanding the effects of these mechanical inputs on marrow function and adaptation requires knowledge of the material behavior of the marrow at multiple scales, the loads that are applied, and the mechanobiology of the cells. This paper reviews the current state of knowledge of each of these factors. Characterization of the marrow mechanical environment and its role in skeletal health and other marrow functions remains incomplete, but research on the topic is increasing, driven by interest in skeletal adaptation and the mechanobiology of cancer metastasis.
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Affiliation(s)
- Kimberly J Curtis
- Tissue Mechanics Laboratory, Bioengineering Graduate Program, University of Notre Dame, Notre Dame, Indiana.,Advanced Diagnostics and Therapeutics Initiative, University of Notre Dame, Notre Dame, Indiana
| | - Alyssa G Oberman
- Tissue Mechanics Laboratory, Bioengineering Graduate Program, University of Notre Dame, Notre Dame, Indiana
| | - Glen L Niebur
- Tissue Mechanics Laboratory, Bioengineering Graduate Program, University of Notre Dame, Notre Dame, Indiana.,Harper Cancer Research Institute, University of Notre Dame, Notre Dame, Indiana.,Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, Indiana
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8
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Yorgan T, David JP, Amling M, Schinke T. The high bone mass phenotype of Lrp5-mutant mice is not affected by megakaryocyte depletion. Biochem Biophys Res Commun 2018; 497:659-666. [PMID: 29454962 DOI: 10.1016/j.bbrc.2018.02.127] [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: 02/12/2018] [Accepted: 02/14/2018] [Indexed: 11/18/2022]
Abstract
Bone remodeling is a continuously ongoing process mediated by bone-resorbing osteoclasts and bone-forming osteoblasts. One key regulator of bone formation is the putative Wnt co-receptor Lrp5, where activating mutations in the extracellular domain cause increased bone formation in mice and humans. We have previously reported that megakaryocyte numbers are increased the bone marrow of mice carrying a high bone mass mutation (HBM) of Lrp5 (Lrp5G170V). Since megakaryocytes can promote bone formation, we addressed the question, if the bone remodeling phenotype of Lrp5G170V mice is affected by megakaryocyte depletion. For that purpose we took advantage of a mouse model carrying a mutation of the Mpl gene, encoding the thrombopoietin receptor. These mice (Mplhlb219) were crossed with Lrp5G170V mice to generate animals carrying both mutations in a homozygous state. Using μCT, undecalcified histology and bone-specific histomorphometry of 12 weeks old littermates we observed that megakaryocyte number was remarkably decreased in Mplhlb219/Lrp5G170V mice, yet the high bone mass phenotype of Lrp5G170V mice was not significantly affected by the homozygous Mpl mutation. Finally, when we analyzed 24 weeks old wildtype and Mplhlb219 mice we did not observe a statistically significant alteration of bone remodeling in the latter ones. Taken together, our results demonstrate that an increased number of bone marrow megakaryocytes does not contribute to the increased bone formation caused by Lrp5 activation.
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Affiliation(s)
- Timur Yorgan
- Department of Osteology and Biomechanics, University Medical Center Hamburg Eppendorf, Hamburg 20246, Germany
| | - Jean-Pierre David
- Department of Osteology and Biomechanics, University Medical Center Hamburg Eppendorf, Hamburg 20246, Germany
| | - Michael Amling
- Department of Osteology and Biomechanics, University Medical Center Hamburg Eppendorf, Hamburg 20246, Germany
| | - Thorsten Schinke
- Department of Osteology and Biomechanics, University Medical Center Hamburg Eppendorf, Hamburg 20246, Germany.
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9
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Olivos DJ, Alvarez M, Cheng YH, Hooker RA, Ciovacco WA, Bethel M, McGough H, Yim C, Chitteti BR, Eleniste PP, Horowitz MC, Srour EF, Bruzzaniti A, Fuchs RK, Kacena MA. Lnk Deficiency Leads to TPO-Mediated Osteoclastogenesis and Increased Bone Mass Phenotype. J Cell Biochem 2017; 118:2231-2240. [PMID: 28067429 DOI: 10.1002/jcb.25874] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 01/06/2017] [Indexed: 11/11/2022]
Abstract
The Lnk adapter protein negatively regulates the signaling of thrombopoietin (TPO), the main megakaryocyte (MK) growth factor. Lnk-deficient (-/-) mice have increased TPO signaling and increased MK number. Interestingly, several mouse models exist in which increased MK number leads to a high bone mass phenotype. Here we report the bone phenotype of these mice. MicroCT and static histomorphometric analyses at 20 weeks showed the distal femur of Lnk-/- mice to have significantly higher bone volume fraction and trabecular number compared to wild-type (WT) mice. Notably, despite a significant increase in the number of osteoclasts (OC), and decreased bone formation rate in Lnk-/- mice compared to WT mice, Lnk-/- mice demonstrated a 2.5-fold greater BV/TV suggesting impaired OC function in vivo. Additionally, Lnk-/- mouse femurs exhibited non-significant increases in mid-shaft cross-sectional area, yet increased periosteal BFR compared to WT femurs was observed. Lnk-/- femurs also had non-significant increases in polar moment of inertia and decreased cortical bone area and thickness, resulting in reduced bone stiffness, modulus, and strength compared to WT femurs. Of note, Lnk is expressed by OC lineage cells and when Lnk-/- OC progenitors are cultured in the presence of TPO, significantly more OC are observed than in WT cultures. Lnk is also expressed in osteoblast (OB) cells and in vitro reduced alkaline phosphatase activity was observed in Lnk-/- cultures. These data suggest that both direct effects on OB and OC as well as indirect effects of MK in regulating OB contributes to the observed high bone mass. J. Cell. Biochem. 118: 2231-2240, 2017. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- David J Olivos
- Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, Indiana.,Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Marta Alvarez
- Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, Indiana
| | - Ying-Hua Cheng
- Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, Indiana
| | - Richard Adam Hooker
- Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, Indiana
| | - Wendy A Ciovacco
- Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, Indiana.,Department of Orthopaedics and Rehabilitation, Yale University School of Medicine, New Haven, Connecticut
| | - Monique Bethel
- Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, Indiana
| | - Haley McGough
- Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, Indiana
| | - Christopher Yim
- Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, Indiana
| | | | - Pierre P Eleniste
- Department of Biomedical and Applied Sciences, Indiana University School of Dentistry, Indianapolis, Indiana
| | - Mark C Horowitz
- Department of Orthopaedics and Rehabilitation, Yale University School of Medicine, New Haven, Connecticut
| | - Edward F Srour
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana.,Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana.,Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana
| | - Angela Bruzzaniti
- Department of Biomedical and Applied Sciences, Indiana University School of Dentistry, Indianapolis, Indiana
| | - Robyn K Fuchs
- Department of Physical Therapy, Indiana University School of Health and Rehabilitation Sciences, Indianapolis, Indiana
| | - Melissa A Kacena
- Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, Indiana.,Department of Orthopaedics and Rehabilitation, Yale University School of Medicine, New Haven, Connecticut
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10
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Leblanc R, Peyruchaud O. The role of platelets and megakaryocytes in bone metastasis. J Bone Oncol 2016; 5:109-111. [PMID: 27761368 PMCID: PMC5063221 DOI: 10.1016/j.jbo.2016.02.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2015] [Revised: 02/17/2016] [Accepted: 02/24/2016] [Indexed: 01/05/2023] Open
Abstract
Blood platelets have been known for more than a century as important partners for successful metastatic dissemination of solid tumors. Cancer cell-induced platelet activation is a key event responsible for prometastatic activity of platelets. Blocking platelet aggregation inhibits the progression of skeletal metastases through mechanisms that are not fully understood. The establishment and progression of bone metastases are strongly influenced by the bone remodeling process. Growth factors and cytokines released upon platelet activation may contribute to both skeletal tumor growth and osteolytic lesions. Megakaryocytes are platelet precursors located in the bone marrow that control bone mass through direct stimulation of osteoblast functions and indirect inhibition of osteoclast activities. Considering growing evidence for their role in the metastatic cascade, platelets and/or megakaryocytes may provide new therapeutic opportunities to help limit bone metastases.
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Affiliation(s)
- Raphael Leblanc
- INSERM U1068, Institute Paoli-Calmettes, Marseille, France; Université Aix-Marseille, Marseille, France
| | - Olivier Peyruchaud
- INSERM, UMR1033, Faculté de Médecine Lyon Est, Lyon, France; Université Claude Bernard Lyon 1, Lyon, France
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11
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Eleniste PP, Patel V, Posritong S, Zero O, Largura H, Cheng YH, Himes ER, Hamilton M, Ekwealor JTB, Kacena MA, Bruzzaniti A. Pyk2 and Megakaryocytes Regulate Osteoblast Differentiation and Migration Via Distinct and Overlapping Mechanisms. J Cell Biochem 2015; 117:1396-406. [PMID: 26552846 DOI: 10.1002/jcb.25430] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 11/09/2015] [Indexed: 01/08/2023]
Abstract
Osteoblast differentiation and migration are necessary for bone formation during bone remodeling. Mice lacking the proline-rich tyrosine kinase Pyk2 (Pyk2-KO) have increased bone mass, in part due to increased osteoblast proliferation. Megakaryocytes (MKs), the platelet-producing cells, also promote osteoblast proliferation in vitro and bone-formation in vivo via a pathway that involves Pyk2. In the current study, we examined the mechanism of action of Pyk2, and the role of MKs, on osteoblast differentiation and migration. We found that Pyk2-KO osteoblasts express elevated alkaline phosphatase (ALP), type I collagen and osteocalcin mRNA levels as well as increased ALP activity, and mineralization, confirming that Pyk2 negatively regulates osteoblast function. Since Pyk2 Y402 phosphorylation is important for its catalytic activity and for its protein-scaffolding functions, we expressed the phosphorylation-mutant (Pyk2(Y402F) ) and kinase-mutant (Pyk2(K457A) ) in Pyk2-KO osteoblasts. Both Pyk2(Y402F) and Pyk2(K457A) reduced ALP activity, whereas only kinase-inactive Pyk2(K457A) inhibited Pyk2-KO osteoblast migration. Consistent with a role for Pyk2 on ALP activity, co-culture of MKs with osteoblasts led to a decrease in the level of phosphorylated Pyk2 (pY402) as well as a decrease in ALP activity. Although, Pyk2-KO osteoblasts exhibited increased migration compared to wild-type osteoblasts, Pyk2 expression was not required necessary for the ability of MKs to stimulate osteoblast migration. Together, these data suggest that osteoblast differentiation and migration are inversely regulated by MKs via distinct Pyk2-dependent and independent signaling pathways. Novel drugs that distinguish between the kinase-dependent or protein-scaffolding functions of Pyk2 may provide therapeutic specificity for the control of bone-related diseases.
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Affiliation(s)
- Pierre P Eleniste
- Department of Biomedical and Applied Sciences, Indiana University School of Dentistry, Indianapolis, Indiana
| | - Vruti Patel
- Department of Biomedical and Applied Sciences, Indiana University School of Dentistry, Indianapolis, Indiana
| | - Sumana Posritong
- Department of Biomedical and Applied Sciences, Indiana University School of Dentistry, Indianapolis, Indiana
| | - Odette Zero
- Department of Biomedical and Applied Sciences, Indiana University School of Dentistry, Indianapolis, Indiana
| | - Heather Largura
- Department of Biomedical and Applied Sciences, Indiana University School of Dentistry, Indianapolis, Indiana
| | - Ying-Hua Cheng
- Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, Indiana
| | - Evan R Himes
- Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, Indiana
| | - Matthew Hamilton
- Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, Indiana
| | - Jenna T B Ekwealor
- Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, Indiana
| | - Melissa A Kacena
- Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, Indiana
| | - Angela Bruzzaniti
- Department of Biomedical and Applied Sciences, Indiana University School of Dentistry, Indianapolis, Indiana
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Meijome TE, Ekwealor JTB, Hooker RA, Cheng YH, Ciovacco WA, Balamohan SM, Srinivasan TL, Chitteti BR, Eleniste PP, Horowitz MC, Srour EF, Bruzzaniti A, Fuchs RK, Kacena MA. C-Mpl Is Expressed on Osteoblasts and Osteoclasts and Is Important in Regulating Skeletal Homeostasis. J Cell Biochem 2015; 117:959-69. [PMID: 26375403 DOI: 10.1002/jcb.25380] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Accepted: 09/14/2015] [Indexed: 11/10/2022]
Abstract
C-Mpl is the receptor for thrombopoietin (TPO), the main megakaryocyte (MK) growth factor, and c-Mpl is believed to be expressed on cells of the hematopoietic lineage. As MKs have been shown to enhance bone formation, it may be expected that mice in which c-Mpl was globally knocked out (c-Mpl(-/-) mice) would have decreased bone mass because they have fewer MKs. Instead, c-Mpl(-/-) mice have a higher bone mass than WT controls. Using c-Mpl(-/-) mice we investigated the basis for this discrepancy and discovered that c-Mpl is expressed on both osteoblasts (OBs) and osteoclasts (OCs), an unexpected finding that prompted us to examine further how c-Mpl regulates bone. Static and dynamic bone histomorphometry parameters suggest that c-Mpl deficiency results in a net gain in bone volume with increases in OBs and OCs. In vitro, a higher percentage of c-Mpl(-/-) OBs were in active phases of the cell cycle, leading to an increased number of OBs. No difference in OB differentiation was observed in vitro as examined by real-time PCR and functional assays. In co-culture systems, which allow for the interaction between OBs and OC progenitors, c-Mpl(-/-) OBs enhanced osteoclastogenesis. Two of the major signaling pathways by which OBs regulate osteoclastogenesis, MCSF/OPG/RANKL and EphrinB2-EphB2/B4, were unaffected in c-Mpl(-/-) OBs. These data provide new findings for the role of MKs and c-Mpl expression in bone and may provide insight into the homeostatic regulation of bone mass as well as bone loss diseases such as osteoporosis.
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Affiliation(s)
- Tomas E Meijome
- Department of Orthopaedic Surgery, Indiana University School of Medicine, Indiana, Indianapolis
| | - Jenna T B Ekwealor
- Department of Orthopaedic Surgery, Indiana University School of Medicine, Indiana, Indianapolis
| | - R Adam Hooker
- Department of Orthopaedic Surgery, Indiana University School of Medicine, Indiana, Indianapolis
| | - Ying-Hua Cheng
- Department of Orthopaedic Surgery, Indiana University School of Medicine, Indiana, Indianapolis
| | - Wendy A Ciovacco
- Department of Orthopaedic Surgery, Indiana University School of Medicine, Indiana, Indianapolis.,Department of Orthopaedics and Rehabilitation, Yale University School of Medicine, New Haven, Connecticut
| | - Sanjeev M Balamohan
- Department of Orthopaedic Surgery, Indiana University School of Medicine, Indiana, Indianapolis
| | - Trishya L Srinivasan
- Department of Orthopaedic Surgery, Indiana University School of Medicine, Indiana, Indianapolis
| | | | - Pierre P Eleniste
- Department of Oral Biology, Indiana University School of Dentistry, Indiana, Indianapolis
| | - Mark C Horowitz
- Department of Orthopaedics and Rehabilitation, Yale University School of Medicine, New Haven, Connecticut
| | - Edward F Srour
- Department of Medicine, Indiana University School of Medicine, Indiana, Indianapolis
| | - Angela Bruzzaniti
- Department of Oral Biology, Indiana University School of Dentistry, Indiana, Indianapolis
| | - Robyn K Fuchs
- Department of Physical Therapy, Indiana University School of Health and Rehabilitation Sciences, Indiana, Indianapolis
| | - Melissa A Kacena
- Department of Orthopaedic Surgery, Indiana University School of Medicine, Indiana, Indianapolis.,Department of Orthopaedics and Rehabilitation, Yale University School of Medicine, New Haven, Connecticut
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13
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Malara A, Abbonante V, Di Buduo CA, Tozzi L, Currao M, Balduini A. The secret life of a megakaryocyte: emerging roles in bone marrow homeostasis control. Cell Mol Life Sci 2015; 72:1517-36. [PMID: 25572292 PMCID: PMC4369169 DOI: 10.1007/s00018-014-1813-y] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Revised: 12/15/2014] [Accepted: 12/19/2014] [Indexed: 12/19/2022]
Abstract
Megakaryocytes are rare cells found in the bone marrow, responsible for the everyday production and release of millions of platelets into the bloodstream. Since the discovery and cloning, in 1994, of their principal humoral factor, thrombopoietin, and its receptor c-Mpl, many efforts have been directed to define the mechanisms underlying an efficient platelet production. However, more recently different studies have pointed out new roles for megakaryocytes as regulators of bone marrow homeostasis and physiology. In this review we discuss the interaction and the reciprocal regulation of megakaryocytes with the different cellular and extracellular components of the bone marrow environment. Finally, we provide evidence that these processes may concur to the reconstitution of the bone marrow environment after injury and their deregulation may lead to the development of a series of inherited or acquired pathologies.
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Affiliation(s)
- Alessandro Malara
- Department of Molecular Medicine, University of Pavia, Via Forlanini 6, 27100 Pavia, Italy
- Laboratory of Biotechnology, IRCCS San Matteo Foundation, Pavia, Italy
| | - Vittorio Abbonante
- Department of Molecular Medicine, University of Pavia, Via Forlanini 6, 27100 Pavia, Italy
- Laboratory of Biotechnology, IRCCS San Matteo Foundation, Pavia, Italy
| | - Christian A. Di Buduo
- Department of Molecular Medicine, University of Pavia, Via Forlanini 6, 27100 Pavia, Italy
- Laboratory of Biotechnology, IRCCS San Matteo Foundation, Pavia, Italy
| | - Lorenzo Tozzi
- Department of Molecular Medicine, University of Pavia, Via Forlanini 6, 27100 Pavia, Italy
- Department of Biomedical Engineering, Tufts University, Medford, MA USA
| | - Manuela Currao
- Department of Molecular Medicine, University of Pavia, Via Forlanini 6, 27100 Pavia, Italy
- Laboratory of Biotechnology, IRCCS San Matteo Foundation, Pavia, Italy
| | - Alessandra Balduini
- Department of Molecular Medicine, University of Pavia, Via Forlanini 6, 27100 Pavia, Italy
- Laboratory of Biotechnology, IRCCS San Matteo Foundation, Pavia, Italy
- Department of Biomedical Engineering, Tufts University, Medford, MA USA
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