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Lung H, Wentworth KL, Moody T, Zamarioli A, Ram A, Ganesh G, Kang M, Ho S, Hsiao EC. Wnt pathway inhibition with the porcupine inhibitor LGK974 decreases trabecular bone but not fibrosis in a murine model with fibrotic bone. JBMR Plus 2024; 8:ziae011. [PMID: 38577521 PMCID: PMC10994528 DOI: 10.1093/jbmrpl/ziae011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 12/22/2023] [Accepted: 01/08/2024] [Indexed: 04/06/2024] Open
Abstract
G protein-coupled receptors (GPCRs) mediate a wide spectrum of physiological functions, including the development, remodeling, and repair of the skeleton. Fibrous dysplasia (FD) of the bone is characterized by fibrotic, expansile bone lesions caused by activating mutations in GNAS. There are no effective therapies for FD. We previously showed that ColI(2.3)+/Rs1+ mice, in which Gs-GPCR signaling was hyper-activated in osteoblastic cell lineages using an engineered receptor strategy, developed a fibrotic bone phenotype with trabecularization that could be reversed by normalizing Gs-GPCR signaling, suggesting that targeting the Gs-GPCR or components of the downstream signaling pathway could serve as a promising therapeutic strategy for FD. The Wnt signaling pathway has been implicated in the pathogenesis of FD-like bone, but the specific Wnts and which cells produce them remain largely unknown. Single-cell RNA sequencing on long-bone stromal cells of 9-wk-old male ColI(2.3)+/Rs1+ mice and littermate controls showed that fibroblastic stromal cells in ColI(2.3)+/Rs1+ mice were expanded. Multiple Wnt ligands were up- or downregulated in different cellular populations, including in non-osteoblastic cells. Treatment with the porcupine inhibitor LGK974, which blocks Wnt signaling broadly, induced partial resorption of the trabecular bone in the femurs of ColI(2.3)+/Rs1+ mice, but no significant changes in the craniofacial skeleton. Bone fibrosis remained evident after treatment. Notably, LGK974 caused significant bone loss in control mice. These results provide new insights into the role of Wnt and Gs-signaling in fibrosis and bone formation in a mouse model of Gs-GPCR pathway overactivation.
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Affiliation(s)
- Hsuan Lung
- Department of Medicine, Division of Endocrinology and Metabolism, The Institute for Human Genetics, and the Eli and Edythe Broad Institute for Regeneration Medicine, University of California, San Francisco, CA 94143, United States
- Oral and Craniofacial Sciences Graduate Program, School of Dentistry, University of California, San Francisco, CA 94143, United States
- Department of Dentistry, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 833, Taiwan
- School of Dentistry, Institute of Oral Medicine, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan
| | - Kelly L Wentworth
- Department of Medicine, Division of Endocrinology and Metabolism, The Institute for Human Genetics, and the Eli and Edythe Broad Institute for Regeneration Medicine, University of California, San Francisco, CA 94143, United States
- Department of Medicine, Division of Endocrinology and Metabolism, University of California, Zuckerberg San Francisco General Hospital, San Francisco, CA 94143, United States
| | - Tania Moody
- Department of Medicine, Division of Endocrinology and Metabolism, The Institute for Human Genetics, and the Eli and Edythe Broad Institute for Regeneration Medicine, University of California, San Francisco, CA 94143, United States
| | - Ariane Zamarioli
- Department of Medicine, Division of Endocrinology and Metabolism, The Institute for Human Genetics, and the Eli and Edythe Broad Institute for Regeneration Medicine, University of California, San Francisco, CA 94143, United States
- Department of Orthopaedics and Anesthesiology, Ribeirao Preto Medical School, University of Sao Paulo, Sao Paulo (SP) 14049-900, Brazil
| | - Apsara Ram
- Department of Medicine, Division of Endocrinology and Metabolism, The Institute for Human Genetics, and the Eli and Edythe Broad Institute for Regeneration Medicine, University of California, San Francisco, CA 94143, United States
| | - Gauri Ganesh
- Department of Medicine, Division of Endocrinology and Metabolism, The Institute for Human Genetics, and the Eli and Edythe Broad Institute for Regeneration Medicine, University of California, San Francisco, CA 94143, United States
| | - Misun Kang
- Oral and Craniofacial Sciences Graduate Program, School of Dentistry, University of California, San Francisco, CA 94143, United States
| | - Sunita Ho
- Oral and Craniofacial Sciences Graduate Program, School of Dentistry, University of California, San Francisco, CA 94143, United States
| | - Edward C Hsiao
- Department of Medicine, Division of Endocrinology and Metabolism, The Institute for Human Genetics, and the Eli and Edythe Broad Institute for Regeneration Medicine, University of California, San Francisco, CA 94143, United States
- Oral and Craniofacial Sciences Graduate Program, School of Dentistry, University of California, San Francisco, CA 94143, United States
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Hopkins C, de Castro LF, Corsi A, Boyce A, Collins MT, Riminucci M, Heegaard AM. Fibrous dysplasia animal models: A systematic review. Bone 2022; 155:116270. [PMID: 34875396 DOI: 10.1016/j.bone.2021.116270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 11/22/2021] [Accepted: 11/25/2021] [Indexed: 12/09/2022]
Abstract
BACKGROUND Fibrous dysplasia (FD) is a rare genetic bone disorder resulting in an overproduction of cAMP leading to a structurally unsound tissue, caused by a genetic mutation in the guanine nucleotide-binding protein gene (GNAS). In order to better understand this disease, several animal models have been developed with different strategies and features. OBJECTIVE Conduct a systematic review to analyze and compare animal models with the causative mutation and features of FD. METHODS A PRISMA search was conducted in Scopus, PubMed, and Web of Science. Studies reporting an in vivo model of FD that expressed the causative mutation were included for analysis. Models without the causative mutation, but developed an FD phenotype and models of FD cell implantation were included for subanalysis. RESULTS Seven unique models were identified. The models were assessed and compared for their face validity, construct validity, mosaicism, and induction methods. This was based on the features of clinical FD that were reported within the categories of: macroscopic features, imaging, histology and histomorphometry, histochemical and cellular markers, and blood/urine markers. LIMITATIONS None of the models reported all features of FD and some features were only reported in one model. This made comparing models a challenge, but indicates areas where further research is necessary. CONCLUSION The benefits and disadvantages of every model were assessed from a practical and scientific standpoint. While all published reports lacked complete data, the models have nonetheless informed our understanding of FD and provided meaningful information to guide researchers in bench and clinical research.
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Affiliation(s)
- Chelsea Hopkins
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Luis Fernandez de Castro
- Skeletal Disorders and Mineral Homeostasis Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, USA
| | - Alessandro Corsi
- Department of Molecular Medicine, Sapienza University of Rome, Rome, Italy
| | - Alison Boyce
- Metabolic Bone Disorders Unit, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, USA
| | - Michael T Collins
- Skeletal Disorders and Mineral Homeostasis Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, USA
| | - Mara Riminucci
- Department of Molecular Medicine, Sapienza University of Rome, Rome, Italy
| | - Anne-Marie Heegaard
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark.
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Barre R, Beton N, Batut A, Accabled F, Sales de Gauzy J, Auriol F, Eddiry S, Tauber M, Laurencin S, Salles JP, Gennero I. Ghrelin uses the GHS-R1a/Gi/cAMP pathway and induces differentiation only in mature osteoblasts. This ghrelin pathway is impaired in AIS patients. Biochem Biophys Rep 2020; 24:100782. [PMID: 32984555 PMCID: PMC7494670 DOI: 10.1016/j.bbrep.2020.100782] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 07/09/2020] [Accepted: 07/13/2020] [Indexed: 12/27/2022] Open
Abstract
We have examined the Acylated Ghrelin (AG)/Gi pathway in different human osteoblastic cell lines. We have found that: 1) AG induces differentiation/mineralization only in mature osteoblasts; 2) the expression of GHS-R1a increases up to the mature cell stage, 3) the action is mediated via the GHS-R/Gi/cAMP pathway only in mature osteoblasts, and 4) osteoblastic cells from adolescent idiopathic scoliosis (AIS) are resistant to the AG/Gi/cAMP pathway. Altogether, these results suggested that AG uses the GHS-R1a/Gi/cAMP pathway to induce differentiation in mature osteoblasts only. This pathway is impaired in AIS osteoblasts. Understanding AG-specific pathways involved in normal and pathological osteoblasts may be useful for developing new treatments for pathologies such as AIS or osteoporosis.
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Affiliation(s)
- Ronan Barre
- Oral Biology Department, Faculty of Odontology, Paul Sabatier Toulouse III University, France
- INSERM, UMR1043, Centre de Physiopathologie de Toulouse Purpan, CHU Toulouse, France
| | - Nicolas Beton
- INSERM, UMR1043, Centre de Physiopathologie de Toulouse Purpan, CHU Toulouse, France
- Faculty of Medicine, Paul Sabatier Toulouse III University, France
| | - Aurélie Batut
- INSERM, UMR1043, Centre de Physiopathologie de Toulouse Purpan, CHU Toulouse, France
- Faculty of Medicine, Paul Sabatier Toulouse III University, France
| | - Frank Accabled
- Faculty of Medicine, Paul Sabatier Toulouse III University, France
- Orthopedic Department, Children Hospital, CHU Toulouse, France
| | - Jerome Sales de Gauzy
- Faculty of Medicine, Paul Sabatier Toulouse III University, France
- Orthopedic Department, Children Hospital, CHU Toulouse, France
| | - Françoise Auriol
- INSERM, UMR1043, Centre de Physiopathologie de Toulouse Purpan, CHU Toulouse, France
- Endocrinology and Bone Pathologies Department, Children Hospital, CHU Toulouse, France
| | - Sanaa Eddiry
- INSERM, UMR1043, Centre de Physiopathologie de Toulouse Purpan, CHU Toulouse, France
- Endocrinology and Bone Pathologies Department, Children Hospital, CHU Toulouse, France
| | - Maithe Tauber
- INSERM, UMR1043, Centre de Physiopathologie de Toulouse Purpan, CHU Toulouse, France
- Faculty of Medicine, Paul Sabatier Toulouse III University, France
- Endocrinology and Bone Pathologies Department, Children Hospital, CHU Toulouse, France
| | - Sara Laurencin
- INSERM, UMR1043, Centre de Physiopathologie de Toulouse Purpan, CHU Toulouse, France
- Periodontology Department, Faculty of Odontology, Paul Sabatier Toulouse III University, France
| | - Jean Pierre Salles
- INSERM, UMR1043, Centre de Physiopathologie de Toulouse Purpan, CHU Toulouse, France
- Faculty of Medicine, Paul Sabatier Toulouse III University, France
- Endocrinology and Bone Pathologies Department, Children Hospital, CHU Toulouse, France
| | - Isabelle Gennero
- INSERM, UMR1043, Centre de Physiopathologie de Toulouse Purpan, CHU Toulouse, France
- Faculty of Medicine, Paul Sabatier Toulouse III University, France
- Clinical Biochemistry Department, Federative Institute of Biology, CHU Toulouse, France
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Bucknor MD, Goel H, Pasco C, Horvai AE, Kazakia GJ. Bone remodeling following MR-guided focused ultrasound: Evaluation with HR-pQCT and FTIR. Bone 2019; 120:347-353. [PMID: 30453088 PMCID: PMC6360100 DOI: 10.1016/j.bone.2018.11.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 11/08/2018] [Accepted: 11/12/2018] [Indexed: 11/21/2022]
Abstract
Magnetic resonance-guided focused ultrasound (MRgFUS) is a novel non-invasive ablation technique that uses focused sound energy to destroy focal tumors, primarily via heat deposition. It is widely used for palliation of pain from bone metastases and has also recently gained popularity as a technique for ablation of benign bone tumors and facet degenerative joint disease (rhizotomy). Clinically, in a subset of patients who have undergone MRgFUS of bone, a variety of treatment responses have been noted on follow-up imaging, including focal sclerosis within the target lesion or more exuberant proliferative changes associated with the periosteum. In this study, high resolution peripheral quantitative CT (HR-pQCT) was used to evaluate remodeling of bone following ablation in a swine model of MRgFUS and compared to samples from a control, non-treated femur. Within each treated femur, two lesions were created: a higher energy focused ultrasound dose was used for one lesion compared to a lower energy dose for the second lesion. Exuberant, extra-cortical bone formation was detected at the higher energy ablation zones, with volumes ranging from 340 mm3 to 1040 mm3. More subtle endosteal and cortical changes were detected in the lower energy ablation zones, however cortical thickness was significantly increased at these sites compared to control bone. For both high and low energy lesions, lower bone mineral density and tissue mineral density was noted in treated regions compared to control regions, consistent with the formation of newly mineralized tissue. Following HR-pQCT analysis, Fourier transform infrared (FTIR) spectroscopy was subsequently used to detect biochemical changes associated with remodeling of bone following MRgFUS, and compared to samples from the control, non-treated femur. Findings were compared with histopathologic examination following hematoxylin-eosin staining. FTIR analysis demonstrated lower mineral/phosphate ratio and increased crystallinity compared to the control samples (p = 0.013). Histopathologic review demonstrated associated areas of endosteal inflammation, scarring, fat necrosis, and new extra-cortical bone formation associated with the ablations. Overall, these findings provide novel characterization of new bone formation following MRgFUS ablation.
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Affiliation(s)
- Matthew D Bucknor
- Department of Radiology and Biomedical Imaging, University of California San Francisco, 185 Berry Street, Suite 350, San Francisco, CA 94107-5705, United States.
| | - Harsh Goel
- Department of Radiology and Biomedical Imaging, University of California San Francisco, 185 Berry Street, Suite 350, San Francisco, CA 94107-5705, United States
| | - Courtney Pasco
- Department of Radiology and Biomedical Imaging, University of California San Francisco, 185 Berry Street, Suite 350, San Francisco, CA 94107-5705, United States
| | - Andrew E Horvai
- Department of Radiology and Biomedical Imaging, University of California San Francisco, 185 Berry Street, Suite 350, San Francisco, CA 94107-5705, United States
| | - Galateia J Kazakia
- Department of Radiology and Biomedical Imaging, University of California San Francisco, 185 Berry Street, Suite 350, San Francisco, CA 94107-5705, United States
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Lung H, Hsiao EC, Wentworth KL. Advances in Models of Fibrous Dysplasia/McCune-Albright Syndrome. Front Endocrinol (Lausanne) 2019; 10:925. [PMID: 32038487 PMCID: PMC6993052 DOI: 10.3389/fendo.2019.00925] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 12/18/2019] [Indexed: 11/13/2022] Open
Abstract
The Gs G-protein coupled receptor pathway is a critical regulator of normal bone formation and function. The Gs pathway increases intracellular cAMP levels by ultimately acting on adenylate cyclase. McCune-Albright Syndrome (MAS) and fibrous dysplasia (FD) of the bone are two proto-typical conditions that result from increased cellular Gs signaling activity. Both are caused by somatic activating mutations in the GNAS gene that encodes for the Gsα subunit. FD bone lesions are particularly difficult to treat because of their variability and because of the lack of effective medical therapies. In this review, we briefly discuss the key clinical presentations of FD/MAS. We also review the current status of mouse models that target the Gs GPCR signaling pathway and human cellular models for FD/MAS. These powerful tools and our improving clinical knowledge will allow further elucidation of the roles of GPCR signaling in FD/MS pathogenesis, and facilitate the development of novel therapies for these medically significant conditions.
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Affiliation(s)
- Hsuan Lung
- Division of Endocrinology and Metabolism and the Institute for Human Genetics, Department of Medicine, University of California, San Francisco, San Francisco, CA, United States
- Oral and Craniofacial Sciences Graduate Program, School of Dentistry, University of California, San Francisco, San Francisco, CA, United States
- Department of Dentistry, Chang Gung Memorial Hospital and College of Medicine, Chang Gung University, Kaohsiung, Taiwan
| | - Edward C. Hsiao
- Division of Endocrinology and Metabolism and the Institute for Human Genetics, Department of Medicine, University of California, San Francisco, San Francisco, CA, United States
- Oral and Craniofacial Sciences Graduate Program, School of Dentistry, University of California, San Francisco, San Francisco, CA, United States
- *Correspondence: Edward C. Hsiao
| | - Kelly L. Wentworth
- Division of Endocrinology and Metabolism and the Institute for Human Genetics, Department of Medicine, University of California, San Francisco, San Francisco, CA, United States
- Division of Endocrinology and Metabolism, Zuckerberg San Francisco General Hospital, University of California, San Francisco, San Francisco, CA, United States
- Kelly L. Wentworth
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6
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Dela Cruz A, Grynpas MD, Mitchell J. Elevated Gα11 expression in osteoblast lineage cells promotes osteoclastogenesis and leads to enhanced trabecular bone accrual in response to pamidronate. Am J Physiol Endocrinol Metab 2016; 310:E811-20. [PMID: 27006198 DOI: 10.1152/ajpendo.00049.2016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 03/15/2016] [Indexed: 11/22/2022]
Abstract
Osteoblastic cells indirectly induce osteoclastogenesis in the bone microenvironment by expressing paracrine factors such as RANKL and M-CSF, leading to increased bone resorption. These cytokines can be regulated by a variety of intracellular pathways, which include G protein-coupled receptor signaling. To explore how enhanced signaling of the Gαq/11 pathway in osteoblast lineage cells may mediate osteoclast formation, we cocultured wild-type (WT) preosteoclasts with BMSCs derived from either WT or transgenic mice with osteoblast-specific overexpression of Gα11 (G11-Tg). G11-Tg cocultures had elevated osteoclast numbers with greater resorptive capacity and increased expression of Rankl, Rankl:Opg (osteoprotegerin), and M-csf compared with cocultures with WT BMSCs. As well, cocultures with G11-Tg BMSCs required a higher concentration of OPG to inhibit osteoclast formation and less angiotensin II to increase osteoclast size. These indicate that G11-Tg osteoblasts drive the increased osteoclast formation and osteopenia seen in G11-Tg mice. Pamidronate treatment of G11-Tg mice restored the trabecular bone loss phenotype, as bone mineral density, bone volume, trabecular number, separation, and expressions of osteoblastic and osteoclastic genes were comparable with WT parameters. These changes were characterized by enhanced accumulation of calcified cartilage in trabecular bone, demonstrating that resorption of the cartilaginous intermediate by osteoclasts is more affected by bisphosphonate treatment in G11-Tg mice. In conclusion, overexpression of Gα11 in osteoblastic cells promotes osteoclastogenesis by upregulation of Rankl and M-csf and bone loss by increased osteoclast resorption of the trabecular bone and cartilaginous matrix.
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Affiliation(s)
- Ariana Dela Cruz
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario Canada
| | - Marc D Grynpas
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada; and Lunenfeld-Tanenbaum Research Institute of Mount Sinai Hospital, Toronto, Ontario, Canada
| | - Jane Mitchell
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario Canada;
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Cain CJ, Valencia JT, Ho S, Jordan K, Mattingly A, Morales BM, Hsiao EC. Increased Gs Signaling in Osteoblasts Reduces Bone Marrow and Whole-Body Adiposity in Male Mice. Endocrinology 2016; 157:1481-94. [PMID: 26901092 PMCID: PMC4816728 DOI: 10.1210/en.2015-1867] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 02/16/2016] [Indexed: 12/21/2022]
Abstract
Bone is increasingly recognized as an endocrine organ that can regulate systemic hormones and metabolism through secreted factors. Although bone loss and increased adiposity appear to be linked clinically, whether conditions of increased bone formation can also change systemic metabolism remains unclear. In this study, we examined how increased osteogenesis affects metabolism by using an engineered G protein-coupled receptor, Rs1, to activate Gs signaling in osteoblastic cells in ColI(2.3)(+)/Rs1(+) transgenic mice. We previously showed that these mice have dramatically increased bone formation resembling fibrous dysplasia of the bone. We found that total body fat was significantly reduced starting at 3 weeks of age. Furthermore, ColI(2.3)(+)/Rs1(+) mice showed reduced O2 consumption and respiratory quotient measures without effects on food intake and energy expenditure. The mice had significantly decreased serum triacylglycerides, leptin, and adiponectin. Resting glucose and insulin levels were unchanged; however, glucose and insulin tolerance tests revealed increased sensitivity to insulin. The mice showed resistance to fat accumulation from a high-fat diet. Furthermore, ColI(2.3)(+)/Rs1(+) mouse bones had dramatically reduced mature adipocyte differentiation, increased Wingless/Int-1 (Wnt) signaling, and higher osteoblastic glucose utilization than controls. These findings suggest that osteoblasts can influence both local and peripheral adiposity in conditions of increased bone formation and suggest a role for osteoblasts in the regulation of whole-body adiposity and metabolic homeostasis.
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Affiliation(s)
- Corey J Cain
- Department of Medicine, Division of Endocrinology and Metabolism; Institute for Human Genetics; and Program in Craniofacial Biology (C.J.C., S.H., K.J., A.M., B.M.M., and E.C.H.); and the Biomedical Sciences Graduate Program (J.T.V. and E.C.H.); University of California, San Francisco, San Francisco, California 94143-0794
| | - Joel T Valencia
- Department of Medicine, Division of Endocrinology and Metabolism; Institute for Human Genetics; and Program in Craniofacial Biology (C.J.C., S.H., K.J., A.M., B.M.M., and E.C.H.); and the Biomedical Sciences Graduate Program (J.T.V. and E.C.H.); University of California, San Francisco, San Francisco, California 94143-0794
| | - Samantha Ho
- Department of Medicine, Division of Endocrinology and Metabolism; Institute for Human Genetics; and Program in Craniofacial Biology (C.J.C., S.H., K.J., A.M., B.M.M., and E.C.H.); and the Biomedical Sciences Graduate Program (J.T.V. and E.C.H.); University of California, San Francisco, San Francisco, California 94143-0794
| | - Kate Jordan
- Department of Medicine, Division of Endocrinology and Metabolism; Institute for Human Genetics; and Program in Craniofacial Biology (C.J.C., S.H., K.J., A.M., B.M.M., and E.C.H.); and the Biomedical Sciences Graduate Program (J.T.V. and E.C.H.); University of California, San Francisco, San Francisco, California 94143-0794
| | - Aaron Mattingly
- Department of Medicine, Division of Endocrinology and Metabolism; Institute for Human Genetics; and Program in Craniofacial Biology (C.J.C., S.H., K.J., A.M., B.M.M., and E.C.H.); and the Biomedical Sciences Graduate Program (J.T.V. and E.C.H.); University of California, San Francisco, San Francisco, California 94143-0794
| | - Blanca M Morales
- Department of Medicine, Division of Endocrinology and Metabolism; Institute for Human Genetics; and Program in Craniofacial Biology (C.J.C., S.H., K.J., A.M., B.M.M., and E.C.H.); and the Biomedical Sciences Graduate Program (J.T.V. and E.C.H.); University of California, San Francisco, San Francisco, California 94143-0794
| | - Edward C Hsiao
- Department of Medicine, Division of Endocrinology and Metabolism; Institute for Human Genetics; and Program in Craniofacial Biology (C.J.C., S.H., K.J., A.M., B.M.M., and E.C.H.); and the Biomedical Sciences Graduate Program (J.T.V. and E.C.H.); University of California, San Francisco, San Francisco, California 94143-0794
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8
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Tascau L, Gardner T, Anan H, Yongpravat C, Cardozo CP, Bauman WA, Lee FY, Oh DS, Tawfeek HA. Activation of Protein Kinase A in Mature Osteoblasts Promotes a Major Bone Anabolic Response. Endocrinology 2016; 157:112-26. [PMID: 26488807 DOI: 10.1210/en.2015-1614] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Protein kinase A (PKA) regulates osteoblast cell function in vitro and is activated by important bone mass modulating agents. We determined whether PKA activation in osteoblasts is sufficient to mediate a bone anabolic response. Thus, a mouse model conditionally expressing a constitutively active PKA (CA-PKA) in osteoblasts (CA-PKA-OB mouse) was developed by crossing a 2.3-kb α1 (I)-collagen promoter-Cre mouse with a floxed-CA-PKA mouse. Primary osteoblasts from the CA-PKA-OB mice exhibited higher basal PKA activity than those from control mice. Microcomputed tomographic analysis revealed that CA-PKA-OB female mice had an 8.6-fold increase in femoral but only 1.16-fold increase in lumbar 5 vertebral bone volume/total volume. Femur cortical thickness and volume were also higher in the CA-PKA-OB mice. In contrast, alterations in many femoral microcomputed tomographic parameters in male CA-PKA-OB mice were modest. Interestingly, the 3-dimensional structure model index was substantially lower both in femur and lumbar 5 of male and female CA-PKA-OB mice, reflecting an increase in the plate to rod-like structure ratio. In agreement, femurs from female CA-PKA-OB mice had greater load to failure and were stiffer compared with those of control mice. Furthermore, the CA-PKA-OB mice had higher levels of serum bone turnover markers and increased osteoblast and osteoclast numbers per total tissue area compared with control animals. In summary, constitutive activation of PKA in osteoblasts is sufficient to increase bone mass and favorably modify bone architecture and improve mechanical properties. PKA activation in mature osteoblasts is, therefore, an important target for designing anabolic drugs for treating diseases with bone loss.
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Affiliation(s)
- Liana Tascau
- National Center for the Medical Consequences of Spinal Cord Injury (C.P.C., W.A.B., H.A.T.), James J. Peters VA Medical Center, Bronx, New York 10468; Center for Orthopaedic Research (T.G., C.Y., F.Y.L.), College of Dental Medicine (D.S.O.), and Department of Molecular Medicine (L.T.), Columbia University, and Departments of Medicine (C.P.C., W.A.B., H.A.T.), Rehabilitation Medicine (C.P.C., W.A.B.), and Pharmacology and Systems Therapeutics (C.P.C.), The Icahn School of Medicine at Mount Sinai, New York, New York 10029; and Sacred Heart Hospital/Temple University (H.A.), Allentown, Pennsylvania 16102
| | - Thomas Gardner
- National Center for the Medical Consequences of Spinal Cord Injury (C.P.C., W.A.B., H.A.T.), James J. Peters VA Medical Center, Bronx, New York 10468; Center for Orthopaedic Research (T.G., C.Y., F.Y.L.), College of Dental Medicine (D.S.O.), and Department of Molecular Medicine (L.T.), Columbia University, and Departments of Medicine (C.P.C., W.A.B., H.A.T.), Rehabilitation Medicine (C.P.C., W.A.B.), and Pharmacology and Systems Therapeutics (C.P.C.), The Icahn School of Medicine at Mount Sinai, New York, New York 10029; and Sacred Heart Hospital/Temple University (H.A.), Allentown, Pennsylvania 16102
| | - Hussein Anan
- National Center for the Medical Consequences of Spinal Cord Injury (C.P.C., W.A.B., H.A.T.), James J. Peters VA Medical Center, Bronx, New York 10468; Center for Orthopaedic Research (T.G., C.Y., F.Y.L.), College of Dental Medicine (D.S.O.), and Department of Molecular Medicine (L.T.), Columbia University, and Departments of Medicine (C.P.C., W.A.B., H.A.T.), Rehabilitation Medicine (C.P.C., W.A.B.), and Pharmacology and Systems Therapeutics (C.P.C.), The Icahn School of Medicine at Mount Sinai, New York, New York 10029; and Sacred Heart Hospital/Temple University (H.A.), Allentown, Pennsylvania 16102
| | - Charlie Yongpravat
- National Center for the Medical Consequences of Spinal Cord Injury (C.P.C., W.A.B., H.A.T.), James J. Peters VA Medical Center, Bronx, New York 10468; Center for Orthopaedic Research (T.G., C.Y., F.Y.L.), College of Dental Medicine (D.S.O.), and Department of Molecular Medicine (L.T.), Columbia University, and Departments of Medicine (C.P.C., W.A.B., H.A.T.), Rehabilitation Medicine (C.P.C., W.A.B.), and Pharmacology and Systems Therapeutics (C.P.C.), The Icahn School of Medicine at Mount Sinai, New York, New York 10029; and Sacred Heart Hospital/Temple University (H.A.), Allentown, Pennsylvania 16102
| | - Christopher P Cardozo
- National Center for the Medical Consequences of Spinal Cord Injury (C.P.C., W.A.B., H.A.T.), James J. Peters VA Medical Center, Bronx, New York 10468; Center for Orthopaedic Research (T.G., C.Y., F.Y.L.), College of Dental Medicine (D.S.O.), and Department of Molecular Medicine (L.T.), Columbia University, and Departments of Medicine (C.P.C., W.A.B., H.A.T.), Rehabilitation Medicine (C.P.C., W.A.B.), and Pharmacology and Systems Therapeutics (C.P.C.), The Icahn School of Medicine at Mount Sinai, New York, New York 10029; and Sacred Heart Hospital/Temple University (H.A.), Allentown, Pennsylvania 16102
| | - William A Bauman
- National Center for the Medical Consequences of Spinal Cord Injury (C.P.C., W.A.B., H.A.T.), James J. Peters VA Medical Center, Bronx, New York 10468; Center for Orthopaedic Research (T.G., C.Y., F.Y.L.), College of Dental Medicine (D.S.O.), and Department of Molecular Medicine (L.T.), Columbia University, and Departments of Medicine (C.P.C., W.A.B., H.A.T.), Rehabilitation Medicine (C.P.C., W.A.B.), and Pharmacology and Systems Therapeutics (C.P.C.), The Icahn School of Medicine at Mount Sinai, New York, New York 10029; and Sacred Heart Hospital/Temple University (H.A.), Allentown, Pennsylvania 16102
| | - Francis Y Lee
- National Center for the Medical Consequences of Spinal Cord Injury (C.P.C., W.A.B., H.A.T.), James J. Peters VA Medical Center, Bronx, New York 10468; Center for Orthopaedic Research (T.G., C.Y., F.Y.L.), College of Dental Medicine (D.S.O.), and Department of Molecular Medicine (L.T.), Columbia University, and Departments of Medicine (C.P.C., W.A.B., H.A.T.), Rehabilitation Medicine (C.P.C., W.A.B.), and Pharmacology and Systems Therapeutics (C.P.C.), The Icahn School of Medicine at Mount Sinai, New York, New York 10029; and Sacred Heart Hospital/Temple University (H.A.), Allentown, Pennsylvania 16102
| | - Daniel S Oh
- National Center for the Medical Consequences of Spinal Cord Injury (C.P.C., W.A.B., H.A.T.), James J. Peters VA Medical Center, Bronx, New York 10468; Center for Orthopaedic Research (T.G., C.Y., F.Y.L.), College of Dental Medicine (D.S.O.), and Department of Molecular Medicine (L.T.), Columbia University, and Departments of Medicine (C.P.C., W.A.B., H.A.T.), Rehabilitation Medicine (C.P.C., W.A.B.), and Pharmacology and Systems Therapeutics (C.P.C.), The Icahn School of Medicine at Mount Sinai, New York, New York 10029; and Sacred Heart Hospital/Temple University (H.A.), Allentown, Pennsylvania 16102
| | - Hesham A Tawfeek
- National Center for the Medical Consequences of Spinal Cord Injury (C.P.C., W.A.B., H.A.T.), James J. Peters VA Medical Center, Bronx, New York 10468; Center for Orthopaedic Research (T.G., C.Y., F.Y.L.), College of Dental Medicine (D.S.O.), and Department of Molecular Medicine (L.T.), Columbia University, and Departments of Medicine (C.P.C., W.A.B., H.A.T.), Rehabilitation Medicine (C.P.C., W.A.B.), and Pharmacology and Systems Therapeutics (C.P.C.), The Icahn School of Medicine at Mount Sinai, New York, New York 10029; and Sacred Heart Hospital/Temple University (H.A.), Allentown, Pennsylvania 16102
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9
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Wattanachanya L, Wang L, Millard SM, Lu WD, O'Carroll D, Hsiao EC, Conklin BR, Nissenson RA. Assessing the osteoblast transcriptome in a model of enhanced bone formation due to constitutive Gs-G protein signaling in osteoblasts. Exp Cell Res 2015; 333:289-302. [PMID: 25704759 DOI: 10.1016/j.yexcr.2015.02.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Revised: 01/29/2015] [Accepted: 02/11/2015] [Indexed: 12/29/2022]
Abstract
G protein-coupled receptor (GPCR) signaling in osteoblasts (OBs) is an important regulator of bone formation. We previously described a mouse model expressing Rs1, an engineered constitutively active Gs-coupled GPCR, under the control of the 2.3 kb Col I promoter. These mice showed a dramatic age-dependent increase in trabecular bone of femurs. Here, we further evaluated the effects of enhanced Gs signaling in OBs on intramembranous bone formation by examining calvariae of 1- and 9-week-old Col1(2.3)/Rs1 mice and characterized the in vivo gene expression specifically occurring in osteoblasts with activated Gs G protein-coupled receptor signaling, at the cellular level rather than in a whole bone. Rs1 calvariae displayed a dramatic increase in bone volume with partial loss of cortical structure. By immunohistochemistry, Osterix was detected in cells throughout the inter-trabecular space while Osteocalcin was expressed predominantly in cells along bone surfaces, suggesting the role of paracrine mediators secreted from OBs driven by 2.3 kb Col I promoter could influence early OB commitment, differentiation, and/or proliferation. Gene expression analysis of calvarial OBs revealed that genes affected by Rs1 signaling include those encoding proteins important for cell differentiation, cytokines and growth factors, angiogenesis, coagulation, and energy metabolism. The set of Gs-GPCRs and other GPCRs that may contribute to the observed skeletal phenotype and candidate paracrine mediators of the effect of Gs signaling in OBs were also determined. Our results identify novel detailed in vivo cellular changes of the anabolic response of the skeleton to Gs signaling in mature OBs.
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Affiliation(s)
- Lalita Wattanachanya
- Endocrine Research Unit, Veterans Affairs Medical Center and Departments of Medicine and Physiology, University of California, San Francisco, CA, USA; Division of Endocrinology and Metabolism, Department of Medicine, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, Thailand.
| | - Liping Wang
- Endocrine Research Unit, Veterans Affairs Medical Center and Departments of Medicine and Physiology, University of California, San Francisco, CA, USA.
| | - Susan M Millard
- Endocrine Research Unit, Veterans Affairs Medical Center and Departments of Medicine and Physiology, University of California, San Francisco, CA, USA.
| | - Wei-Dar Lu
- Endocrine Research Unit, Veterans Affairs Medical Center and Departments of Medicine and Physiology, University of California, San Francisco, CA, USA.
| | - Dylan O'Carroll
- Endocrine Research Unit, Veterans Affairs Medical Center and Departments of Medicine and Physiology, University of California, San Francisco, CA, USA.
| | - Edward C Hsiao
- Division of Endocrinology and Metabolism, Department of Medicine, University of California, San Francisco, CA, USA.
| | - Bruce R Conklin
- Gladstone Institute of Cardiovascular Disease, San Francisco, CA, USA; Department of Medicine, University of California, San Francisco, CA, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA, USA.
| | - Robert A Nissenson
- Endocrine Research Unit, Veterans Affairs Medical Center and Departments of Medicine and Physiology, University of California, San Francisco, CA, USA.
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Disrupted bone remodeling leads to cochlear overgrowth and hearing loss in a mouse model of fibrous dysplasia. PLoS One 2014; 9:e94989. [PMID: 24788917 PMCID: PMC4006800 DOI: 10.1371/journal.pone.0094989] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Accepted: 03/20/2014] [Indexed: 02/05/2023] Open
Abstract
Normal hearing requires exquisite cooperation between bony and sensorineural structures within the cochlea. For example, the inner ear secretes proteins such as osteoprotegrin (OPG) that can prevent cochlear bone remodeling. Accordingly, diseases that affect bone regulation can also result in hearing loss. Patients with fibrous dysplasia develop trabecular bone overgrowth resulting in hearing loss if the lesions affect the temporal bones. Unfortunately, the mechanisms responsible for this hearing loss, which could be sensorineural and/or conductive, remain unclear. In this study, we used a unique transgenic mouse model of increased Gs G-protein coupled receptor (GPCR) signaling induced by expression of an engineered receptor, Rs1, in osteoblastic cells. These ColI(2.3)+/Rs1+ mice showed dramatic bone lesions that histologically and radiologically resembled fibrous dysplasia. We found that ColI(2.3)+/Rs1+ mice showed progressive and severe conductive hearing loss. Ossicular chain impingement increased with the size and number of dysplastic lesions. While sensorineural structures were unaffected, ColI(2.3)+/Rs1+ cochleae had abnormally high osteoclast activity, together with elevated tartrate resistant acid phosphatase (TRAP) activity and receptor activator of nuclear factor kappa-B ligand (Rankl) mRNA expression. ColI(2.3)+/Rs1+ cochleae also showed decreased expression of Sclerostin (Sost), an antagonist of the Wnt signaling pathway that normally increases bone formation. The osteocyte canalicular networks of ColI(2.3)+/Rs1+ cochleae were disrupted and showed abnormal osteocyte morphology. The osteocytes in the ColI(2.3)+/Rs1+ cochleae showed increased expression of matrix metalloproteinase 13 (MMP-13) and TRAP, both of which can support osteocyte-mediated peri-lacunar remodeling. Thus, while the ossicular chain impingement is sufficient to account for the progressive hearing loss in fibrous dysplasia, the deregulation of bone remodeling extends to the cochlea as well. Our findings suggest that factors regulating bone remodeling, including peri-lacunar remodeling by osteocytes, may be useful targets for treating the bony overgrowths and hearing changes of fibrous dysplasia and other bony pathologies.
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11
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Activated Gs signaling in osteoblastic cells alters the hematopoietic stem cell niche in mice. Blood 2012; 120:3425-35. [PMID: 22859604 DOI: 10.1182/blood-2011-11-395418] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Adult hematopoiesis occurs primarily in the BM space where hematopoietic cells interact with stromal niche cells. Despite this close association, little is known about the specific roles of osteoblastic lineage cells (OBCs) in maintaining hematopoietic stem cells (HSCs), and how conditions affecting bone formation influence HSC function. Here we use a transgenic mouse model with the ColI(2.3) promoter driving a ligand-independent, constitutively active 5HT4 serotonin receptor (Rs1) to address how the massive increase in trabecular bone formation resulting from increased G(s) signaling in OBCs impacts HSC function and blood production. Rs1 mice display fibrous dysplasia, BM aplasia, progressive loss of HSC numbers, and impaired megakaryocyte/erythrocyte development with defective recovery after hematopoietic injury. These hematopoietic defects develop without compensatory extramedullary hematopoiesis, and the loss of HSCs occurs despite a paradoxical expansion of stromal niche cells with putative HSC-supportive activity (ie, endothelial, mesenchymal, and osteoblastic cells). However, Rs1-expressing OBCs show decreased expression of key HSC-supportive factors and impaired ability to maintain HSCs. Our findings indicate that long-term activation of G(s) signaling in OBCs leads to contextual changes in the BM niche that adversely affect HSC maintenance and blood homeostasis.
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