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Wan J, He D, Xie J, Chen Z. A novel GNAS mutation in pseudohypoparathyroidism type 1a with articular flexion deformity: A case report. Open Life Sci 2024; 19:20220918. [PMID: 39071491 PMCID: PMC11282909 DOI: 10.1515/biol-2022-0918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Revised: 06/11/2024] [Accepted: 06/13/2024] [Indexed: 07/30/2024] Open
Abstract
Pseudohypoparathyroidism (PHP) type 1a (PHP 1a) is a rare hereditary disorder characterized by target organ resistance to hormonal signaling and the Albright hereditary osteodystrophy (AHO) phenotype, which features round facial features, short fingers, subcutaneous calcifications, short stature, obesity, and intellectual disability. Progressive osseous heteroplasia (POH) is another rare disorder characterized by heterotopic ossification (HO) that progressively affects skin, subcutaneous tissues, and deep skeletal muscle. PHP 1a is inherited maternally due to a GNAS mutation, while pure POH is inherited paternally. This case study presented a Chinese boy with congenital hypothyroidism, tonic-clonic seizures, hypoparathyroidism, AHO, POH, and joint fixation deformity. Sequencing analysis of GNAS-Gsα revealed a heterozygous C.432+2T>C(P.?) variant (NM_000516.7) affecting the canonical splice donor site of intron 5 in the boy and his mother, indicating maternal inheritance of a GNAS mutation. The patient was diagnosed with POH overlap syndrome (POH/PHP 1a). Following calcium and calcitriol supplementation, he experienced a reduction in seizures, and surgery was performed to correct the joint fixation deformity caused by HO. This case report provided valuable insights into the genotype-phenotype correlations of POH overlap syndrome and underscored the significance of genetic testing in diagnosing rare diseases.
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Affiliation(s)
- Jinxing Wan
- Department of Endocrinology, The Quzhou Affiliated Hospital of Wenzhou Medical University, Quzhou People’s Hospital, Quzhou, 324000, Zhejiang, China
| | - Dongjuan He
- Department of Endocrinology, The Quzhou Affiliated Hospital of Wenzhou Medical University, Quzhou People’s Hospital, Quzhou, 324000, Zhejiang, China
| | - Jun Xie
- Department of Orthopedics, The Quzhou Affiliated Hospital of Wenzhou Medical University, Quzhou People’s Hospital, No. 100 of Minjiang Avenue, Quzhou, 324000, Zhejiang, China
| | - Zhizhi Chen
- Department of Neurology, The Quzhou Affliliated Hospital of Wenzhou Medical University, Quzhou People’s Hospital, Quzhou, 324000, Zhejiang, China
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McMullan P, Maye P, Root SH, Yang Q, Edie S, Rowe D, Kalajzic I, Germain-Lee EL. Hair follicle-resident progenitor cells are a major cellular contributor to heterotopic subcutaneous ossifications in a mouse model of Albright hereditary osteodystrophy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.18.599506. [PMID: 38948860 PMCID: PMC11213030 DOI: 10.1101/2024.06.18.599506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
Heterotopic ossifications (HOs) are the pathologic process by which bone inappropriately forms outside of the skeletal system. Despite HOs being a persistent clinical problem in the general population, there are no definitive strategies for their prevention and treatment due to a limited understanding of the cellular and molecular mechanisms contributing to lesion development. One disease in which the development of heterotopic subcutaneous ossifications (SCOs) leads to morbidity is Albright hereditary osteodystrophy (AHO). AHO is caused by heterozygous inactivation of GNAS, the gene that encodes the α-stimulatory subunit (Gαs) of G proteins. Previously, we had shown using our laboratory's AHO mouse model that SCOs develop around hair follicles (HFs). Here we show that SCO formation occurs due to inappropriate expansion and differentiation of HF-resident stem cells into osteoblasts. We also show in AHO patients and mice that Secreted Frizzled Related Protein 2 (SFRP2) expression is upregulated in regions of SCO formation and that elimination of Sfrp2 in male AHO mice exacerbates SCO development. These studies provide key insights into the cellular and molecular mechanisms contributing to SCO development and have implications for potential therapeutic modalities not only for AHO patients but also for patients suffering from HOs with other etiologies.
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Affiliation(s)
- Patrick McMullan
- Department of Pediatrics, University of Connecticut School of Medicine, Farmington, CT
- Department of Reconstructive Sciences, Center for Regenerative Medicine and Skeletal Development, University of Connecticut School of Dental Medicine, Farmington, CT
| | - Peter Maye
- Department of Reconstructive Sciences, Center for Regenerative Medicine and Skeletal Development, University of Connecticut School of Dental Medicine, Farmington, CT
| | - Sierra H. Root
- Department of Reconstructive Sciences, Center for Regenerative Medicine and Skeletal Development, University of Connecticut School of Dental Medicine, Farmington, CT
| | - Qingfen Yang
- Department of Pediatrics, University of Connecticut School of Medicine, Farmington, CT
- Department of Reconstructive Sciences, Center for Regenerative Medicine and Skeletal Development, University of Connecticut School of Dental Medicine, Farmington, CT
| | | | - David Rowe
- Department of Reconstructive Sciences, Center for Regenerative Medicine and Skeletal Development, University of Connecticut School of Dental Medicine, Farmington, CT
| | - Ivo Kalajzic
- Department of Reconstructive Sciences, Center for Regenerative Medicine and Skeletal Development, University of Connecticut School of Dental Medicine, Farmington, CT
| | - Emily L. Germain-Lee
- Department of Pediatrics, University of Connecticut School of Medicine, Farmington, CT
- Department of Reconstructive Sciences, Center for Regenerative Medicine and Skeletal Development, University of Connecticut School of Dental Medicine, Farmington, CT
- Albright Center, Division of Endocrinology & Diabetes, Connecticut Children’s, Farmington, CT
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Elli FM, Mattinzoli D, Ikehata M, Bagnaresi F, Maffini MA, Del Sindaco G, Pagnano A, Lucca C, Messa P, Arosio M, Castellano G, Alfieri CM, Mantovani G. Targeted silencing of GNAS in a human model of osteoprogenitor cells results in the deregulation of the osteogenic differentiation program. Front Endocrinol (Lausanne) 2024; 15:1296886. [PMID: 38828417 PMCID: PMC11140044 DOI: 10.3389/fendo.2024.1296886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 04/22/2024] [Indexed: 06/05/2024] Open
Abstract
Introduction The dysregulation of cell fate toward osteoprecursor cells associated with most GNAS-based disorders may lead to episodic de novo extraskeletal or ectopic bone formation in subcutaneous tissues. The bony lesion distribution suggests the involvement of abnormal differentiation of mesenchymal stem cells (MSCs) and/or more committed precursor cells. Data from transgenic mice support the concept that GNAS is a crucial factor in regulating lineage switching between osteoblasts (OBs) and adipocyte fates. The mosaic nature of heterotopic bone lesions suggests that GNAS genetic defects provide a sensitized background for ectopic osteodifferentiation, but the underlying molecular mechanism remains largely unknown. Methods The effect of GNAS silencing in the presence and/or absence of osteoblastic stimuli was evaluated in the human L88/5 MSC line during osteodifferentiation. A comparison of the data obtained with data coming from a bony lesion from a GNAS-mutated patient was also provided. Results Our study adds some dowels to the current fragmented notions about the role of GNAS during osteoblastic differentiation, such as the premature transition of immature OBs into osteocytes and the characterization of the differences in the deposed bone matrix. Conclusion We demonstrated that our cell model partially replicates the in vivo behavior results, resulting in an applicable human model to elucidate the pathophysiology of ectopic bone formation in GNAS-based disorders.
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Affiliation(s)
- Francesca Marta Elli
- Endocrinology Unit, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Deborah Mattinzoli
- Department of Nephrology, Dialysis and Renal Transplantation, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Masami Ikehata
- Department of Nephrology, Dialysis and Renal Transplantation, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Francesca Bagnaresi
- Endocrinology Unit, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Maria A. Maffini
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Giulia Del Sindaco
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Angela Pagnano
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Camilla Lucca
- Endocrinology Unit, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Piergiorgio Messa
- Department of Nephrology, Dialysis and Renal Transplantation, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Maura Arosio
- Endocrinology Unit, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Giuseppe Castellano
- Department of Nephrology, Dialysis and Renal Transplantation, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Carlo M. Alfieri
- Department of Nephrology, Dialysis and Renal Transplantation, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Giovanna Mantovani
- Endocrinology Unit, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
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Ma J, Mo W, Sun J, Li Y, Han T, Mao H. Progressive osseous heteroplasia in a 5-year-old boy with a novel mutation in exon 2 of GNAS: a case presentation and literature review. BMC Musculoskelet Disord 2023; 24:247. [PMID: 37003989 PMCID: PMC10064707 DOI: 10.1186/s12891-023-06371-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 03/23/2023] [Indexed: 04/03/2023] Open
Abstract
BACKGROUND Progressive osseous heteroplasia (POH) is a rare genetic condition that causes progressive ossification. This usually results from an inactivating mutation of the paternal GNAS gene. Herein, we report a case of POH caused by a novel mutation in exon 2 of the GNAS gene. CASE PRESENTATION A 5-year-old Chinese boy was referred to our hospital for a growing mass in his right foot. Although laboratory findings were normal, radiographic imaging revealed severe ossification in his right foot and smaller areas of intramuscular ossification in his arms and legs. A de novo mutation (c.175C > T, p.Q59X) in exon 2 of the GNAS gene was identified, prompting a diagnosis of POH. We conducted a systematic literature review to better understand this rare disease. CONCLUSION We have discovered that a de novo nonsense mutation in exon 2 of GNAS can lead to POH. Our literature review revealed that ankylosis of the extremities is the primary clinical outcome in patients with POH. Unlike other conditions such as fibrodysplasia ossificans progressiva (FOP), patients with POH do not experience respiratory failure. However, much remains to be learned about the relationship between the type of GNAS gene mutation and the resulting POH symptoms. Further research is needed to understand this complex and rare disease. This case adds to our current understanding of POH and will contribute to future studies and treatments.
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Affiliation(s)
- Jing Ma
- Department of Immunology, Ministry of Education Key Laboratory of Major Diseases in Children, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, No. 56 Nan Li Shi Lu, Beijing, 100045, China
| | - Wenxiu Mo
- Department of Immunology, Ministry of Education Key Laboratory of Major Diseases in Children, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, No. 56 Nan Li Shi Lu, Beijing, 100045, China
| | - Jiapeng Sun
- Department of Immunology, Ministry of Education Key Laboratory of Major Diseases in Children, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, No. 56 Nan Li Shi Lu, Beijing, 100045, China
| | - Yan Li
- Department of Immunology, Ministry of Education Key Laboratory of Major Diseases in Children, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, No. 56 Nan Li Shi Lu, Beijing, 100045, China
| | - Tongxin Han
- Department of Immunology, Ministry of Education Key Laboratory of Major Diseases in Children, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, No. 56 Nan Li Shi Lu, Beijing, 100045, China
| | - Huawei Mao
- Department of Immunology, Ministry of Education Key Laboratory of Major Diseases in Children, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, No. 56 Nan Li Shi Lu, Beijing, 100045, China.
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5
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Basha G, Cottle AG, Pretheeban T, Chan KY, Witzigmann D, Young RN, Rossi FM, Cullis PR. Lipid nanoparticle-mediated silencing of osteogenic suppressor GNAS leads to osteogenic differentiation of mesenchymal stem cells in vivo. Mol Ther 2022; 30:3034-3051. [PMID: 35733339 PMCID: PMC9481989 DOI: 10.1016/j.ymthe.2022.06.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 05/09/2022] [Accepted: 06/17/2022] [Indexed: 11/21/2022] Open
Abstract
Approved drugs for the treatment of osteoporosis can prevent further bone loss but do not stimulate bone formation. Approaches that improve bone density in metabolic diseases are needed. Therapies that take advantage of the ability of mesenchymal stem cells (MSCs) to differentiate into various osteogenic lineages to treat bone disorders are of particular interest. Here we examine the ability of small interfering RNA (siRNA) to enhance osteoblast differentiation and bone formation by silencing the negative suppressor gene GNAS in bone MSCs. Using clinically validated lipid nanoparticle (LNP) siRNA delivery systems, we show that silencing the suppressor gene GNAS in vitro in MSCs leads to molecular and phenotypic changes similar to those seen in osteoblasts. Further, we demonstrate that these LNP-siRNAs can transfect a large proportion of mice MSCs in the compact bone following intravenous injection. Transfection of MSCs in various animal models led to silencing of GNAS and enhanced differentiation of MSCs into osteoblasts. These data demonstrate the potential for LNP delivery of siRNA to enhance the differentiation of MSCs into osteoblasts, and suggests that they are a promising approach for the treatment of osteoporosis and other bone diseases.
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Affiliation(s)
- Genc Basha
- NanoMedicines Research Group, Department of Biochemistry and Molecular Biology, Life Sciences Institute, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada.
| | - Andrew G Cottle
- NanoMedicines Research Group, Department of Biochemistry and Molecular Biology, Life Sciences Institute, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada
| | - Thavaneetharajah Pretheeban
- School of Biomedical Engineering and Department of Medical Genetics, Biomedical Research Centre University of British Columbia, 2222 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada
| | - Karen Yt Chan
- NanoMedicines Research Group, Department of Biochemistry and Molecular Biology, Life Sciences Institute, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada
| | - Dominik Witzigmann
- NanoMedicines Research Group, Department of Biochemistry and Molecular Biology, Life Sciences Institute, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada; NanoMedicines Innovation Network (NMIN), University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Robert N Young
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
| | - Fabio Mv Rossi
- School of Biomedical Engineering and Department of Medical Genetics, Biomedical Research Centre University of British Columbia, 2222 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada
| | - Pieter R Cullis
- NanoMedicines Research Group, Department of Biochemistry and Molecular Biology, Life Sciences Institute, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada; NanoMedicines Innovation Network (NMIN), University of British Columbia, Vancouver, BC V6T 1Z3, Canada
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6
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McMullan P, Germain-Lee EL. Aberrant Bone Regulation in Albright Hereditary Osteodystrophy dueto Gnas Inactivation: Mechanisms and Translational Implications. Curr Osteoporos Rep 2022; 20:78-89. [PMID: 35226254 DOI: 10.1007/s11914-022-00719-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/06/2021] [Indexed: 11/03/2022]
Abstract
PURPOSE OF REVIEW This review highlights the impact of Gnas inactivation on both bone remodeling and the development of heterotopic subcutaneous ossifications in Albright hereditary osteodystrophy (AHO). Here we discuss recent advancements in understanding the pathophysiologic mechanisms of the aberrant bone development in AHO as well as potential translational implications. RECENT FINDINGS Gnas inactivation can regulate the differentiation and function of not only osteoblasts but also osteoclasts and osteocytes. Investigations utilizing a mouse model of AHO generated by targeted disruption of Gnas have revealed that bone formation and resorption are differentially affected based upon the parental origin of the Gnas mutation. Data suggest that Gnas inactivation leads to heterotopic bone formation within subcutaneous tissue by changing the connective tissue microenvironment, thereby promoting osteogenic differentiation of tissue-resident mesenchymal progenitors. Observed variations in bone formation and resorption based upon the parental origin of the Gnas mutation warrant future investigations and may have implications in the management and treatment of AHO and related conditions. Additionally, studies of heterotopic bone formation due to Gnas inactivation have identified an essential role of sonic hedgehog signaling, which could have therapeutic implications not only for AHO and related conditions but also for heterotopic bone formation in a wide variety of settings in which aberrant bone formation is a cause of significant morbidity.
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Affiliation(s)
- Patrick McMullan
- Department of Pediatrics, Division of Pediatric Endocrinology & Diabetes, University of Connecticut School of Medicine, 505 Farmington Ave, 2nd floor, Farmington, CT, 06032, USA
- Department of Reconstructive Sciences, Center for Regenerative Medicine and Skeletal Development, University of Connecticut School of Dental Medicine, Farmington, CT, USA
| | - Emily L Germain-Lee
- Department of Pediatrics, Division of Pediatric Endocrinology & Diabetes, University of Connecticut School of Medicine, 505 Farmington Ave, 2nd floor, Farmington, CT, 06032, USA.
- Department of Reconstructive Sciences, Center for Regenerative Medicine and Skeletal Development, University of Connecticut School of Dental Medicine, Farmington, CT, USA.
- Albright Center, Connecticut Children's, Farmington, CT, USA.
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7
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Fang F, Sup M, Luzzi A, Ferrer X, Thomopoulos S. Hedgehog signaling underlying tendon and enthesis development and pathology. Matrix Biol 2022; 105:87-103. [PMID: 34954379 PMCID: PMC8821161 DOI: 10.1016/j.matbio.2021.12.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 12/18/2021] [Accepted: 12/19/2021] [Indexed: 02/08/2023]
Abstract
Hedgehog (Hh) signaling has been widely acknowledged to play essential roles in many developmental processes, including endochondral ossification and growth plate maintenance. Furthermore, a rising number of studies have shown that Hh signaling is necessary for tendon enthesis development. Specifically, the well-tuned regulation of Hh signaling during development drives the formation of a mineral gradient across the tendon enthesis fibrocartilage. However, aberrant Hh signaling can also lead to pathologic heterotopic ossification in tendon or osteophyte formation at the enthesis. Therefore, the therapeutic potential of Hh signaling modulation for treating tendon and enthesis diseases remains uncertain. For example, increased Hh signaling may enhance tendon-to-bone healing by promoting the formation of mineralized fibrocartilage at the healing interface, but pathologic heterotopic ossification may also be triggered in the adjacent tendon. Further work is needed to elucidate the distinct functions of Hh signaling in the tendon and enthesis to support the development of therapies that target the pathway.
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Affiliation(s)
- Fei Fang
- Department of Orthopedic Surgery, Columbia University, Black Building, Room 1408, 650W 168 ST, New York, NY 10032-3702, United States
| | - McKenzie Sup
- Department of Biomedical Engineering, Columbia University, New York, NY, United States
| | - Andrew Luzzi
- Department of Orthopedic Surgery, Columbia University, Black Building, Room 1408, 650W 168 ST, New York, NY 10032-3702, United States
| | - Xavier Ferrer
- Department of Orthopedic Surgery, Columbia University, Black Building, Room 1408, 650W 168 ST, New York, NY 10032-3702, United States
| | - Stavros Thomopoulos
- Department of Orthopedic Surgery, Columbia University, Black Building, Room 1408, 650W 168 ST, New York, NY 10032-3702, United States; Department of Biomedical Engineering, Columbia University, New York, NY, United States.
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Cong Q, Liu Y, Zhou T, Zhou Y, Xu R, Cheng C, Chung HS, Yan M, Zhou H, Liao Z, Gao B, Bocobo GA, Covington TA, Song HJ, Su P, Yu PB, Yang Y. A self-amplifying loop of YAP and SHH drives formation and expansion of heterotopic ossification. Sci Transl Med 2021; 13:13/599/eabb2233. [PMID: 34162750 PMCID: PMC8638088 DOI: 10.1126/scitranslmed.abb2233] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 12/03/2020] [Accepted: 05/30/2021] [Indexed: 12/15/2022]
Abstract
Heterotopic ossification (HO) occurs as a common complication after injury or in genetic disorders. The mechanisms underlying HO remain incompletely understood, and there are no approved prophylactic or secondary treatments available. Here, we identify a self-amplifying, self-propagating loop of Yes-associated protein (YAP)-Sonic hedgehog (SHH) as a core molecular mechanism underlying diverse forms of HO. In mouse models of progressive osseous heteroplasia (POH), a disease caused by null mutations in GNAS, we found that Gnas-/- mesenchymal cells secreted SHH, which induced osteoblast differentiation of the surrounding wild-type cells. We further showed that loss of Gnas led to activation of YAP transcription activity, which directly drove Shh expression. Secreted SHH further induced YAP activation, Shh expression, and osteoblast differentiation in surrounding wild-type cells. This self-propagating positive feedback loop was both necessary and sufficient for HO expansion and could act independently of Gnas in fibrodysplasia ossificans progressiva (FOP), another genetic HO, and nonhereditary HO mouse models. Genetic or pharmacological inhibition of YAP or SHH abolished HO in POH and FOP and acquired HO mouse models without affecting normal bone homeostasis, providing a previously unrecognized therapeutic rationale to prevent, reduce, and shrink HO.
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Affiliation(s)
- Qian Cong
- Department of Developmental Biology, Harvard School of Dental Medicine, Harvard Stem Cell Institute, 188 Longwood Ave., Boston, MA 02115, USA
| | - Yuchen Liu
- Department of Developmental Biology, Harvard School of Dental Medicine, Harvard Stem Cell Institute, 188 Longwood Ave., Boston, MA 02115, USA
| | - Taifeng Zhou
- Department of Developmental Biology, Harvard School of Dental Medicine, Harvard Stem Cell Institute, 188 Longwood Ave., Boston, MA 02115, USA
| | - Yaxing Zhou
- Department of Developmental Biology, Harvard School of Dental Medicine, Harvard Stem Cell Institute, 188 Longwood Ave., Boston, MA 02115, USA
| | - Ruoshi Xu
- Department of Developmental Biology, Harvard School of Dental Medicine, Harvard Stem Cell Institute, 188 Longwood Ave., Boston, MA 02115, USA
| | - Caiqi Cheng
- Department of Developmental Biology, Harvard School of Dental Medicine, Harvard Stem Cell Institute, 188 Longwood Ave., Boston, MA 02115, USA
| | - Hye Soo Chung
- Department of Developmental Biology, Harvard School of Dental Medicine, Harvard Stem Cell Institute, 188 Longwood Ave., Boston, MA 02115, USA
| | - Meijun Yan
- Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115, USA
| | - Hang Zhou
- Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115, USA
| | - Zhiheng Liao
- Department of Orthopaedic Surgery, Guangdong Provincial Key Laboratory of Orthopedics and Traumatology, First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China
| | - Bo Gao
- Department of Developmental Biology, Harvard School of Dental Medicine, Harvard Stem Cell Institute, 188 Longwood Ave., Boston, MA 02115, USA
| | - Geoffrey A Bocobo
- Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115, USA
| | - Taylor A Covington
- Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115, USA
| | - Hyeon Ju Song
- Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115, USA
| | - Peiqiang Su
- Department of Orthopaedic Surgery, Guangdong Provincial Key Laboratory of Orthopedics and Traumatology, First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China
| | - Paul B Yu
- Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115, USA
| | - Yingzi Yang
- Department of Developmental Biology, Harvard School of Dental Medicine, Harvard Stem Cell Institute, 188 Longwood Ave., Boston, MA 02115, USA.
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Abstract
Parathyroid hormone (PTH), which is primarily regulated by extracellular calcium changes, controls calcium and phosphate homeostasis. Different diseases are derived from PTH deficiency (hypoparathyroidism), excess (hyperparathyroidism) and resistance (pseudohypoparathyroidism, PHP). Pseudohypoparathyroidism was historically classified into subtypes according to the presence or not of inherited PTH resistance associated or not with features of Albright's hereditary osteodystrophy and deep and progressive ectopic ossifications. The growing knowledge on the PTH/PTHrP signaling pathway showed that molecular defects affecting different members of this pathway determined distinct, yet clinically related disorders, leading to the proposal of a new nomenclature and classification encompassing all disorders, collectively termed inactivating PTH/PTHrP signaling disorders (iPPSD).
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Affiliation(s)
- Giovanna Mantovani
- University of Milan, Dept. Clinical Sciences and Commmunity Health, Via Lamarmora 5, Milan, Italy; Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Endocrinology Unit, Via Lamarmora 5, 20122, Milan, Italy.
| | - Francesca Marta Elli
- Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Endocrinology Unit, Via Lamarmora 5, 20122, Milan, Italy.
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10
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Elli FM, Mantovani G. Pseudohypoparathyroidism, acrodysostosis, progressive osseous heteroplasia: different names for the same spectrum of diseases? Endocrine 2021; 72:611-618. [PMID: 33179219 PMCID: PMC8159830 DOI: 10.1007/s12020-020-02533-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 10/24/2020] [Indexed: 12/27/2022]
Abstract
Pseudohypoparathyroidism (PHP), the first known post-receptorial hormone resistance, derives from a partial deficiency of the α subunit of the stimulatory G protein (Gsα), a key component of the PTH/PTHrP signaling pathway. Since its first description, different studies unveiled, beside the molecular basis for PHP, the existence of different subtypes and of diseases in differential diagnosis associated with genetic alterations in other genes of the PTH/PTHrP pathway. The clinical and molecular overlap among PHP subtypes and with different but related disorders make both differential diagnosis and genetic counseling challenging. Recently, a proposal to group all these conditions under the novel term "inactivating PTH/PTHrP signaling disorders (iPPSD)" was promoted and, soon afterwards, the first international consensus statement on the diagnosis and management of these disorders has been published. This review will focus on the major and minor features characterizing PHP/iPPSDs as a group and on the specificities as well as the overlap associated with the most frequent subtypes.
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Affiliation(s)
- Francesca Marta Elli
- Endocrinology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Giovanna Mantovani
- Endocrinology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy.
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Tan X, Guo Y, Liu Y, Liu C, Pei L. Symptomatic spinal cord compression: an uncommon symptom in pseudohypoparathyroidism. Ann N Y Acad Sci 2021; 1503:38-47. [PMID: 33660862 DOI: 10.1111/nyas.14584] [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] [Received: 12/28/2020] [Revised: 02/02/2021] [Accepted: 02/05/2021] [Indexed: 12/27/2022]
Abstract
We describe symptomatic spinal cord compression associated with pseudohypoparathyroidism (PHP) in a young female patient and reviewed similar cases previously reported in the literature. The characteristics of these cases were analyzed from etiology, clinical subtypes, symptoms, treatment, and prognosis. Neurological examination revealed functional upper extremities with bilateral lower extremity paraplegia. Laboratory tests showed hypocalcemia, hyperphosphatemia, and elevated parathyroid hormone; high-throughput sequencing showed a heterozygous GNAS mutation in exon 12, specifically c.1006C > T (p.R336W). Imaging findings showed multilevel spinal stenosis with significant spinal cord compression at the T2-T3 level. Seventeen cases with similar characteristics were reviewed. We found that the primary clinical manifestation of these patients was bilateral lower extremity spastic paraplegia. Multilevel spinal cord compression was commonly observed, especially at the lower cervical and upper thoracic spinal cord. Most of the patients had poor surgical treatment outcome and prognosis. Clinicians should be aware of paraplegia due to spinal cord compression as a rare neurological complication in patients with PHP. Early diagnosis and treatment of PHP is one basis for preventing severe spinal cord-related complications.
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Affiliation(s)
- Xiaoping Tan
- Department of Neurology, Shengjing Hospital of China Medical University, Shenyang, Liaoning, PR China
| | - Yang Guo
- Department of Neurology, Shengjing Hospital of China Medical University, Shenyang, Liaoning, PR China
| | - Yan Liu
- Department of Neurology, Shengjing Hospital of China Medical University, Shenyang, Liaoning, PR China
| | - Cong Liu
- Department of Endocrinology, Shengjing Hospital of China Medical University, Shenyang, Liaoning, PR China
| | - Lina Pei
- Department of Endocrinology, Shengjing Hospital of China Medical University, Shenyang, Liaoning, PR China
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12
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Happle R. Progressive Osseous Heteroplasia is not an Autosomal Dominant Trait but Reflects Superimposed Mosaicism in Different GNAS Inactivation Disorders. Indian Dermatol Online J 2021; 12:316-318. [PMID: 33959533 PMCID: PMC8088155 DOI: 10.4103/idoj.idoj_584_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Revised: 09/11/2020] [Accepted: 10/20/2020] [Indexed: 11/04/2022] Open
Abstract
Progressive osseous heteroplasia (POH) is a rarely occurring genetic condition characterized by severe segmental ossification involving the skin and deep connective tissues including the muscles. So far, the disorder is generally described as an autosomal dominant trait. By contrast, the following arguments are in favor of the alternative concept that POH should rather be taken as a non-specific segmental manifestation of different GNAS inactivation disorders such as Albright hereditary osteodystrophy (AHO) with hormone resistance, AHO without hormone resistance, and osteomatosis cutis. Presently, POH has got its own OMIM number 166350 but this is obviously wrong because the disorder does not reflect heterozygosity for a GNAS mutation. Conversely, the disorder is most likely due to an early event of postzygotic loss of heterozygosity with loss of the corresponding wild-type allele. This alternative concept, as proposed in 2016, offers a plausible explanation for the following features of POH. Familial occurrence is usually absent. POH is usually observed in families with one of the three GNAS inactivation disorders as mentioned above. Mosaicism is suggested by the pronounced segmental manifestation of POH and by its lateralization. Some patients have, in addition to POH, bilaterally disseminated features of osteomatosis cutis or AHO, and other patients have family members with one of these nonsegmental disorders. Remarkably, POH tends to appear much earlier than the nonsegmental GNAS inactivation disorders. - Molecular support of the concept was documented in a superficial variant of POH called 'plate-like osteoma cutis'. In several other autosomal dominant skin disorders, molecular corroboration of the theory of superimposed mosaicism has been provided. - For all of these reasons, it is unlikely that POH can further be taken as a distinct autosomal dominant trait. Generation of more molecular data in multiple cases of POH occurring in GNAS inactivation disorders will be crucial to corroborate the proposed concept.
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Affiliation(s)
- Rudolf Happle
- Department of Dermatology, Medical Center-University of Freiburg, Freiburg, Germany
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13
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Li D, Bupp C, March ME, Hakonarson H, Levine MA. Intragenic Deletions of GNAS in Pseudohypoparathyroidism Type 1A Identify a New Region Affecting Methylation of Exon A/B. J Clin Endocrinol Metab 2020; 105:5841615. [PMID: 32436958 PMCID: PMC7947960 DOI: 10.1210/clinem/dgaa286] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Accepted: 05/15/2020] [Indexed: 12/13/2022]
Abstract
CONTEXT Pseudohypoparathyroidism type 1A (PHP1A) and pseudopseudohypoparathyroidism (PPHP) are caused by inactivating mutations in the exons of GNAS that encode the alpha-subunit of the stimulatory G protein (Gsα). In some cases abnormal methylation of exon A/B of GNAS, a hallmark of PHP1B, has been reported. OBJECTIVE To identify the underlying genetic basis for PHP1A/PPHP in patients in whom molecular defects were not detected by GNAS sequencing and microarray-based analysis of copy number variations. METHODS Whole genome sequencing (WGS) and pyrosequencing of differentially methylated regions (DMRs) of GNAS using genomic deoxyribonucleic acid from affected patients. RESULTS We identified 2 novel heterozygous GNAS deletions: a 6.4 kb deletion that includes exon 2 of GNAS in the first proband that was associated with normal methylation (57%) of exon A/B DMR, and a 1438 bp deletion in a second PHP1A patient that encompasses the promoter region and 5' untranslated region of Gsα transcripts, which was inherited from his mother with PPHP. This deletion was associated with reduced methylation (32%) of exon A/B DMR. CONCLUSIONS WGS can detect exonic and intronic mutations, including deletions that are too small to be identified by microarray analysis, and therefore is more sensitive than other techniques for molecular analysis of PHP1A/PPHP. One of the deletions we identified led to reduced methylation of exon A/B DMR, further refining a region needed for normal imprinting of this DMR. We propose that deletion of this region can explain why some PHP1A patients have reduced of methylation of the exon A/B DMR.
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Affiliation(s)
- Dong Li
- Center for Applied Genomics, The Children’s Hospital of Philadelphia, Philadelphia, PA
| | | | - Michael E March
- Center for Applied Genomics, The Children’s Hospital of Philadelphia, Philadelphia, PA
| | - Hakon Hakonarson
- Center for Applied Genomics, The Children’s Hospital of Philadelphia, Philadelphia, PA
- Department of Pediatrics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - Michael A Levine
- Department of Pediatrics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
- Division of Endocrinology and Diabetes, The Children’s Hospital of Philadelphia, Philadelphia, PA
- Correspondence and Reprint Requests: Michael A. Levine, MD, Division of Endocrinology and Diabetes, The Children’s Hospital of Philadelphia, Abramson Research Center, Room 510A, 3615 Civic Center Boulevard, Philadelphia, PA 19104. E-mail:
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14
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Abstract
PURPOSE OF REVIEW This review is timely given the 2018 publication of the first international Consensus Statement for the diagnosis and management of pseudohypoparathyroidism (PHP) and related disorders. The purpose of this review is to provide the knowledge needed to recognize and manage PHP1A, pseudopseudohypoparathyroidism (PPHP) and PHP1B - the most common of the subtypes - with an overview of the entire spectrum and to provide a concise summary of management for clinical use. This review will draw from recent literature as well as personal experience in evaluating hundreds of children and adults with PHP. RECENT FINDINGS Progress is continually being made in understanding the mechanisms underlying the PHP spectrum. Every year, through clinical and laboratory studies, the phenotypes are elucidated in more detail, as are clinical issues such as short stature, brachydactyly, subcutaneous ossifications, cognitive/behavioural impairments, obesity and metabolic disturbances. Headed by a European PHP consortium, experts worldwide published the first international Consensus that provides detailed guidance in a systematic manner and will lead to exponential progress in understanding and managing these disorders. SUMMARY As more knowledge is gained from clinical and laboratory investigations, the mechanisms underlying the abnormalities associated with PHP are being uncovered as are improvements in management.
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15
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Ware AD, Brewer N, Meyers C, Morris C, McCarthy E, Shore EM, James AW. Differential Vascularity in Genetic and Nonhereditary Heterotopic Ossification. Int J Surg Pathol 2019; 27:859-867. [PMID: 31250694 DOI: 10.1177/1066896919857135] [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] [Indexed: 12/14/2022]
Abstract
Introduction. Nonhereditary heterotopic ossification (NHO) is a common complication of trauma. Progressive osseous heteroplasia (POH) and fibrodysplasia ossificans progressiva (FOP) are rare genetic causes of heterotopic bone. In this article, we detail the vascular patterning associated with genetic versus NHO. Methods. Vascular histomorphometric analysis was performed on patient samples from POH, FOP, and NHO. Endpoints for analysis included blood vessel (BV) number, area, density, size, and wall thickness. Results. Results demonstrated conserved temporal dynamic changes in vascularity across all heterotopic ossification lesions. Immature areas had the highest BV number, while the more mature foci had the highest BV area. Most vascular parameters were significantly increased in genetic as compared with NHO. Discussion. In sum, both genetic and NHO show temporospatial variation in vascularity. These findings suggest that angiogenic pathways are potential therapeutic targets in both genetic and nonhereditary forms of heterotopic ossification.
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Abstract
Skeletal development is exquisitely controlled both spatially and temporally by cell signaling networks. Gαs is the stimulatory α-subunit in a heterotrimeric G protein complex transducing the signaling of G-protein-coupled receptors (GPCRs), responsible for controlling both skeletal development and homeostasis. Gαs, encoded by the GNAS gene in humans, plays critical roles in skeletal development and homeostasis by regulating commitment, differentiation and maturation of skeletal cells. Gαs-mediated signaling interacts with the Wnt and Hedgehog signaling pathways, both crucial regulators of skeletal development, remodeling and injury repair. Genetic mutations that disrupt Gαs functions cause human disorders with severe skeletal defects, such as fibrous dysplasia of bone and heterotopic bone formation. This chapter focuses on the crucial roles of Gαs signaling during skeletal development and homeostasis, and the pathological mechanisms underlying skeletal diseases caused by GNAS mutations.
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Affiliation(s)
- Qian Cong
- Department of Developmental Biology, Harvard School of Dental Medicine, Boston, MA, United States
| | - Ruoshi Xu
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Department of Cariology and Endodontology, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Yingzi Yang
- Department of Developmental Biology, Harvard School of Dental Medicine, Boston, MA, United States.
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17
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Elli FM, Pereda A, Linglart A, Perez de Nanclares G, Mantovani G. Parathyroid hormone resistance syndromes - Inactivating PTH/PTHrP signaling disorders (iPPSDs). Best Pract Res Clin Endocrinol Metab 2018; 32:941-954. [PMID: 30665554 DOI: 10.1016/j.beem.2018.09.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Metabolic disorders caused by impairments of the Gsα/cAMP/PKA pathway affecting the signaling of PTH/PTHrP lead to features caused by non-responsiveness of target organs, in turn leading to manifestations similar to the deficiency of the hormone itself. Pseudohypoparathyroidism (PHP) and related disorders derive from a defect of the α subunit of the stimulatory G protein (Gsα) or of downstream effectors of the same pathway, such as the PKA regulatory subunit 1A and the phosphodiesterase type 4D. The increasing knowledge on these diseases made the actual classification of PHP outdated as it does not include related conditions such as acrodysostosis (ACRDYS) or progressive osseous heteroplasia (POH), so that a new nomenclature and classification has been recently proposed grouping these disorders under the term "inactivating PTH/PTHrP signaling disorder" (iPPSD). This review will focus on the pathophysiology, clinical and molecular aspects of these rare, heterogeneous but closely related diseases.
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Affiliation(s)
- Francesca Marta Elli
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Endocrinology Unit, Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy.
| | - Arrate Pereda
- Molecular (Epi)Genetics Laboratory, BioAraba National Health Institute, OSI Araba University Hospital, Vitoria-Gasteiz, Spain.
| | - Agnès Linglart
- APHP, Department of Paediatric Endocrinology and Diabetes for Children, Bicêtre Paris-Sud Hospital, Le Kremlin-Bicêtre, France; APHP, Reference Center for Rare Disorders of Calcium and Phosphate Metabolism, Filière OSCAR and Plateforme d'Expertise Maladies Rares Paris-Sud, Bicêtre Paris-Sud Hospital, Le Kremlin Bicêtre, France.
| | - Guiomar Perez de Nanclares
- Molecular (Epi)Genetics Laboratory, BioAraba National Health Institute, OSI Araba University Hospital, Vitoria-Gasteiz, Spain.
| | - Giovanna Mantovani
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Endocrinology Unit, Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy.
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18
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Pacifici M. Acquired and congenital forms of heterotopic ossification: new pathogenic insights and therapeutic opportunities. Curr Opin Pharmacol 2018; 40:51-58. [PMID: 29614433 PMCID: PMC6015534 DOI: 10.1016/j.coph.2018.03.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 03/20/2018] [Indexed: 12/27/2022]
Abstract
Heterotopic ossification (HO) involves the formation and accumulation of extraskeletal bone tissue at the expense of local tissues including muscles and connective tissues. There are common forms of HO that are triggered by extensive trauma, burns and other bodily insults, and there are also rare congenital severe forms of HO that occur in children with Fibrodysplasia Ossificans Progressiva or Progressive Osseous Heteroplasia. Given that HO is often preceded by inflammation, current treatments usually involve anti-inflammatory drugs alone or in combination with local irradiation, but are not very effective. Recent studies have provided novel insights into the pathogenesis of acquired and genetic forms of HO and have used the information to conceive and test new and more specific therapies in animal models. In this review, I provide salient examples of these exciting and promising advances that are undoubtedly paving the way toward resolution of this debilitating and at times fatal disease.
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MESH Headings
- Animals
- Anti-Inflammatory Agents/therapeutic use
- Anti-Inflammatory Agents, Non-Steroidal/therapeutic use
- Bone Diseases, Metabolic/diagnosis
- Bone Diseases, Metabolic/genetics
- Bone Diseases, Metabolic/physiopathology
- Bone Diseases, Metabolic/therapy
- Bone and Bones/drug effects
- Bone and Bones/pathology
- Bone and Bones/physiopathology
- Bone and Bones/radiation effects
- Drug Discovery/methods
- Genetic Predisposition to Disease
- Humans
- Molecular Targeted Therapy
- Myositis Ossificans/diagnosis
- Myositis Ossificans/genetics
- Myositis Ossificans/physiopathology
- Myositis Ossificans/therapy
- Ossification, Heterotopic/diagnosis
- Ossification, Heterotopic/genetics
- Ossification, Heterotopic/physiopathology
- Ossification, Heterotopic/therapy
- Osteogenesis/drug effects
- Osteogenesis/genetics
- Osteogenesis/radiation effects
- Phenotype
- Skin Diseases, Genetic/diagnosis
- Skin Diseases, Genetic/genetics
- Skin Diseases, Genetic/physiopathology
- Skin Diseases, Genetic/therapy
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Affiliation(s)
- Maurizio Pacifici
- Translational Research Program in Pediatric Orthopaedics, Division of Orthopaedic Surgery, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.
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19
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Mantovani G, Elli FM. Multiple hormone resistance and alterations of G-protein-coupled receptors signaling. Best Pract Res Clin Endocrinol Metab 2018; 32:141-154. [PMID: 29678282 DOI: 10.1016/j.beem.2018.01.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Metabolic disorders deriving from the non-responsiveness of target organs to hormones, which manifest clinically similar to the deficiency of a given hormone itself, derive from molecular alterations affecting specific hormone receptors. Pseudohypoparathyroidism (PHP) and related disorders exemplify an unusual form of hormone resistance as the underlying molecular defect is a partial deficiency of the α subunit of the stimulatory G protein (Gsα), a key regulator of cAMP signaling pathway, or, as more recently described, of downstream effector proteins of the same pathway, such as PKA regulatory subunit 1A (R1A) and phosphodyestarase type 4D (PDE4D). In this group of diseases, resistance to hormones such as PTH, TSH, gonadotropins and GHRH may be variably present, so that the clinical and molecular overlap among these different but related disorders represents a challenge for endocrinologists as to differential diagnosis and genetic counseling. This review will describe the presenting features of multiple resistance in PHP and related disorders, focusing on both our current understanding and future challenges.
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Affiliation(s)
- Giovanna Mantovani
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Endocrinology Unit, Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy.
| | - Francesca Marta Elli
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Endocrinology Unit, Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy.
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20
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Xu R, Hu J, Zhou X, Yang Y. Heterotopic ossification: Mechanistic insights and clinical challenges. Bone 2018; 109:134-142. [PMID: 28855144 DOI: 10.1016/j.bone.2017.08.025] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Accepted: 08/26/2017] [Indexed: 02/05/2023]
Abstract
Bone formation is exquisitely controlled both spatially and temporally. Heterotopic ossification (HO) is pathological bone formation in soft tissues that often leads to deleterious outcomes. Inherited genetic forms of HO can be life-threatening and can happen as early as in infancy. However, there is currently no effective treatment for HO as the underlying cellular and molecular mechanisms have not been completely elucidated. Trauma-induced non-genetic forms of HO often occur as a common complication after surgeries or accidents, and the location of HO occurrence largely determines the symptom and outcome. While it has been difficult to determine the complicated factors causing HO, recent advancement in identifying cellular and molecular mechanism causing the genetic forms of HO may provide important insights in all HO. Here in this review, we summarize recent studies on HO to provide a current status of both clinical options of HO treatments and mechanical understanding of HO.
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Affiliation(s)
- Ruoshi Xu
- Department of Developmental Biology, Harvard School of Dental Medicine, 188 Longwood Ave. Boston, MA 02215, USA; State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases & Dept. of Cariology and Endodonics West China Hospital of Stomatology, Sichuan University, No. 14, Section 3, South Renmin Rd., Chengdu, 610041, China
| | - Jiajie Hu
- Department of Developmental Biology, Harvard School of Dental Medicine, 188 Longwood Ave. Boston, MA 02215, USA
| | - Xuedong Zhou
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases & Dept. of Cariology and Endodonics West China Hospital of Stomatology, Sichuan University, No. 14, Section 3, South Renmin Rd., Chengdu, 610041, China.
| | - Yingzi Yang
- Department of Developmental Biology, Harvard School of Dental Medicine, 188 Longwood Ave. Boston, MA 02215, USA.
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21
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Abstract
GNAS is a complex imprinted gene encoding the alpha-subunit of the stimulatory heterotrimeric G protein (Gsα). GNAS gives rise to additional gene products that exhibit exclusively maternal or paternal expression, such as XLαs, a large variant of Gsα that shows exclusively paternal expression and is partly identical to the latter. Gsα itself is expressed biallelically in most tissues, although the expression occurs predominantly from the maternal allele in a small set of tissues, such as renal proximal tubules. Inactivating mutations in Gsα-coding GNAS exons are responsible for Albright's hereditary osteodystrophy (AHO), which refers to a constellation of physical and developmental disorders including obesity, short stature, brachydactyly, cognitive impairment, and heterotopic ossification. Patients with Gsα mutations can present with AHO in the presence or absence of end-organ resistance to multiple hormones including parathyroid hormone. Maternal Gsα mutations lead to AHO with hormone resistance (i.e. pseudohypoparathyroidism type-Ia), whereas paternal mutations cause AHO alone (i.e. pseudo-pseudohypoparathyroidism). Heterotopic ossification associated with AHO develops through intramembranous bone formation and is limited to dermis and subcutis. In rare cases carrying Gsα mutations, however, ossifications progress into deep connective tissue and skeletal muscle, a disorder termed progressive osseous heteroplasia (POH). Here I briefly review the genetic, clinical, and molecular aspects of these disorders caused by inactivating GNAS mutations, with particular emphasis on heterotopic ossification.
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Affiliation(s)
- Murat Bastepe
- Endocrine Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, United States.
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22
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Salemi P, Skalamera Olson JM, Dickson LE, Germain-Lee EL. Ossifications in Albright Hereditary Osteodystrophy: Role of Genotype, Inheritance, Sex, Age, Hormonal Status, and BMI. J Clin Endocrinol Metab 2018; 103:158-168. [PMID: 29059381 PMCID: PMC5761497 DOI: 10.1210/jc.2017-00860] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Accepted: 10/16/2017] [Indexed: 12/14/2022]
Abstract
CONTEXT Albright hereditary osteodystrophy (AHO) is caused by heterozygous inactivating mutations in GNAS. Depending on the parental origin of the mutated allele, patients develop either pseudohypoparathyroidism type 1A (PHP1A), with multihormone resistance and severe obesity, or pseudopseudohypoparathyroidism (PPHP), without hormonal abnormalities or marked obesity. Subcutaneous ossifications (SCOs) are a source of substantial morbidity in both PHP1A and PPHP. OBJECTIVE This study investigated the previously undetermined prevalence of SCO formation in PHP1A vs PPHP as well as possible correlations with genotype, sex, age, hormonal resistance, and body mass index (BMI). DESIGN This study evaluated patients with AHO for SCOs by physical examination performed by one consistent physician over 16 years. SETTING Albright Clinic, Kennedy Krieger Institute; Institute for Clinical and Translational Research, Johns Hopkins Hospital; Albright Center, Connecticut Children's Medical Center. PATIENTS We evaluated 67 patients with AHO (49 with PHP1A, 18 with PPHP) with documented mutations in GNAS. MAIN OUTCOME MEASURES Relationships of SCOs to genotype, sex, age, hormonal resistance, and BMI. RESULTS Forty-seven of 67 participants (70.1%) had SCOs. Patients with PHP1A and PPHP had similar prevalences and degrees of ossification formation. Patients with frameshift and nonsense mutations had much more extensive SCOs than those with missense mutations. Males were affected more than females. There was no correlation with hormonal status or BMI. CONCLUSIONS There is a similar prevalence of SCOs in PHP1A and PPHP, and the extent of SCO formation correlates with the severity of the mutation. Males are affected more extensively than females, and the SCOs tend to worsen with age.
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Affiliation(s)
- Parissa Salemi
- Department of Pediatrics, Division of Pediatric Endocrinology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | | | - Lauren E Dickson
- Albright Center and Center for Rare Bone Disorders, Division of Pediatric Endocrinology & Diabetes, Connecticut Children's Medical Center, Farmington, Connecticut
| | - Emily L Germain-Lee
- Department of Pediatrics, Division of Pediatric Endocrinology, Johns Hopkins University School of Medicine, Baltimore, Maryland
- Albright Clinic, Kennedy Krieger Institute, Baltimore, Maryland
- Albright Center and Center for Rare Bone Disorders, Division of Pediatric Endocrinology & Diabetes, Connecticut Children's Medical Center, Farmington, Connecticut
- Department of Pediatrics, University of Connecticut School of Medicine, Farmington, Connecticut
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23
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Turan S. Current Nomenclature of Pseudohypoparathyroidism: Inactivating Parathyroid Hormone/Parathyroid Hormone-Related Protein Signaling Disorder. J Clin Res Pediatr Endocrinol 2017; 9:58-68. [PMID: 29280743 PMCID: PMC5790322 DOI: 10.4274/jcrpe.2017.s006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Disorders related to parathyroid hormone (PTH) resistance and PTH signaling pathway impairment are historically classified under the term of pseudohypoparathyroidism (PHP). The disease was first described and named by Fuller Albright and colleagues in 1942. Albright hereditary osteodystrophy (AHO) is described as an associated clinical entity with PHP, characterized by brachydactyly, subcutaneous ossifications, round face, short stature and a stocky build. The classification of PHP is further divided into PHP-Ia, pseudo-PHP (pPHP), PHP-Ib, PHP-Ic and PHP-II according to the presence or absence of AHO, together with an in vivo response to exogenous PTH and the measurement of Gsα protein activity in peripheral erythrocyte membranes in vitro. However, PHP classification fails to differentiate all patients with different clinical and molecular findings for PHP subtypes and classification become more complicated with more recent molecular characterization and new forms having been identified. So far, new classifications have been established by the EuroPHP network to cover all disorders of the PTH receptor and its signaling pathway. Inactivating PTH/PTH-related protein signaling disorder (iPPSD) is the new name proposed for a group of these disorders and which can be further divided into subtypes - iPPSD1 to iPPSD6. These are termed, starting from PTH receptor inactivation mutation (Eiken and Blomstrand dysplasia) as iPPSD1, inactivating Gsα mutations (PHP-Ia, PHP-Ic and pPHP) as iPPSD2, loss of methylation of GNAS DMRs (PHP-Ib) as iPPSD3, PRKAR1A mutations (acrodysostosis type 1) as iPPSD4, PDE4D mutations (acrodysostosis type 2) as iPPSD5 and PDE3A mutations (autosomal dominant hypertension with brachydactyly) as iPPSD6. iPPSDx is reserved for unknown molecular defects and iPPSDn+1 for new molecular defects which are yet to be described. With these new classifications, the aim is to clarify the borders of each different subtype of disease and make the classification according to molecular pathology. The iPPSD group is designed to be expandable and new classifications will readily fit into it as necessary.
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Affiliation(s)
- Serap Turan
- Marmara University Faculty of Medicine, Department of Pediatric Endocrinology, İstanbul, Turkey
,* Address for Correspondence: Marmara University Faculty of Medicine, Department of Pediatric Endocrinology, İstanbul, Turkey Phone: +90 216 625 45 45 E-mail:
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24
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Tafaj O, Jüppner H. Pseudohypoparathyroidism: one gene, several syndromes. J Endocrinol Invest 2017; 40:347-356. [PMID: 27995443 DOI: 10.1007/s40618-016-0588-4] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 11/25/2016] [Indexed: 01/04/2023]
Abstract
Pseudohypoparathyroidism (PHP) and pseudopseudohypoparathyroidism (PPHP) are caused by mutations and/or epigenetic changes at the complex GNAS locus on chromosome 20q13.3 that undergoes parent-specific methylation changes at several sites. GNAS encodes the alpha-subunit of the stimulatory G protein (Gsα) and several splice variants thereof. Heterozygous inactivating mutations involving the maternal GNAS exons 1-13 cause PHP type Ia (PHP1A). Because of much reduced paternal Gsα expression in certain tissues, such as the proximal renal tubules, thyroid, and pituitary, there is little or no Gsα protein in the presence of maternal GNAS mutations, thus leading to PTH-resistant hypocalcemia and hyperphosphatemia. When located on the paternal allele, the same or similar GNAS mutations are the cause of PPHP. Besides biochemical abnormalities, patients affected by PHP1A show developmental abnormalities, referred to as Albrights hereditary osteodystrophy (AHO). Some, but not all of these AHO features are encountered also in patients affected by PPHP, who typically show no laboratory abnormalities. Autosomal dominant PHP type Ib (AD-PHP1B) is caused by heterozygous maternal deletions within GNAS or STX16, which are associated with loss-of-methylation (LOM) at exon A/B alone or at all maternally methylated GNAS exons. LOM at exon A/B and the resulting biallelic expression of A/B transcripts reduces Gsα expression, thus leading to hormonal resistance. Epigenetic changes at all differentially methylated GNAS regions are also observed in sporadic PHP1B, the most frequent disease variant, which remains unresolved at the molecular level, except for rare cases with paternal uniparental isodisomy or heterodisomy of chromosome 20q (patUPD20q).
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Affiliation(s)
- O Tafaj
- Endocrine Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Thier 10, 50 Blossom Street, Boston, MA, 02114, USA
| | - H Jüppner
- Endocrine Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Thier 10, 50 Blossom Street, Boston, MA, 02114, USA.
- Pediatric Nephrology Unit, Department of Pediatrics, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
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Thiele S, Mantovani G, Barlier A, Boldrin V, Bordogna P, De Sanctis L, Elli FM, Freson K, Garin I, Grybek V, Hanna P, Izzi B, Hiort O, Lecumberri B, Pereda A, Saraff V, Silve C, Turan S, Usardi A, Werner R, de Nanclares GP, Linglart A. From pseudohypoparathyroidism to inactivating PTH/PTHrP signalling disorder (iPPSD), a novel classification proposed by the EuroPHP network. Eur J Endocrinol 2016; 175:P1-P17. [PMID: 27401862 DOI: 10.1530/eje-16-0107] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Revised: 07/05/2016] [Accepted: 07/07/2016] [Indexed: 12/21/2022]
Abstract
OBJECTIVE Disorders caused by impairments in the parathyroid hormone (PTH) signalling pathway are historically classified under the term pseudohypoparathyroidism (PHP), which encompasses rare, related and highly heterogeneous diseases with demonstrated (epi)genetic causes. The actual classification is based on the presence or absence of specific clinical and biochemical signs together with an in vivo response to exogenous PTH and the results of an in vitro assay to measure Gsa protein activity. However, this classification disregards other related diseases such as acrodysostosis (ACRDYS) or progressive osseous heteroplasia (POH), as well as recent findings of clinical and genetic/epigenetic background of the different subtypes. Therefore, the EuroPHP network decided to develop a new classification that encompasses all disorders with impairments in PTH and/or PTHrP cAMP-mediated pathway. DESIGN AND METHODS Extensive review of the literature was performed. Several meetings were organised to discuss about a new, more effective and accurate way to describe disorders caused by abnormalities of the PTH/PTHrP signalling pathway. RESULTS AND CONCLUSIONS After determining the major and minor criteria to be considered for the diagnosis of these disorders, we proposed to group them under the term 'inactivating PTH/PTHrP signalling disorder' (iPPSD). This terminology: (i) defines the common mechanism responsible for all diseases; (ii) does not require a confirmed genetic defect; (iii) avoids ambiguous terms like 'pseudo' and (iv) eliminates the clinical or molecular overlap between diseases. We believe that the use of this nomenclature and classification will facilitate the development of rationale and comprehensive international guidelines for the diagnosis and treatment of iPPSDs.
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Affiliation(s)
- Susanne Thiele
- Division of Experimental Pediatric Endocrinology and DiabetesDepartment of Pediatrics, University of Lübeck, Lübeck, Germany
| | - Giovanna Mantovani
- Fondazione IRCCS Ca' Granda Ospedale Maggiore PoliclinicoEndocrinology and Diabetology Unit, Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Anne Barlier
- APHMHôpital la Conception, Laboratory of Molecular Biology, Marseille, France
| | - Valentina Boldrin
- Fondazione IRCCS Ca' Granda Ospedale Maggiore PoliclinicoEndocrinology and Diabetology Unit, Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Paolo Bordogna
- Fondazione IRCCS Ca' Granda Ospedale Maggiore PoliclinicoEndocrinology and Diabetology Unit, Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Luisa De Sanctis
- Department of Public Health and Pediatric SciencesUniversity of Torino, Torino, Italy
| | - Francesca M Elli
- Fondazione IRCCS Ca' Granda Ospedale Maggiore PoliclinicoEndocrinology and Diabetology Unit, Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Kathleen Freson
- Department of Cardiovascular SciencesCenter for Molecular and Vascular Biology, University of Leuven, Leuven, Belgium
| | - Intza Garin
- Molecular (Epi)Genetics LaboratoryBioAraba National Health Institute, OSI Araba University Hospital, Vitoria-Gasteiz, Spain
| | - Virginie Grybek
- APHPReference Center for rare disorders of the Calcium and Phosphate Metabolism, filière OSCAR and Plateforme d'Expertise Maladies Rares Paris-Sud, Hôpital Bicêtre Paris Sud, Le Kremlin Bicêtre, France
- INSERM U1169Hôpital Bicêtre, Le Kremlin Bicêtre, et Université Paris-Saclay, Le Kremlin Bicêtre, France
| | - Patrick Hanna
- APHPReference Center for rare disorders of the Calcium and Phosphate Metabolism, filière OSCAR and Plateforme d'Expertise Maladies Rares Paris-Sud, Hôpital Bicêtre Paris Sud, Le Kremlin Bicêtre, France
- INSERM U1169Hôpital Bicêtre, Le Kremlin Bicêtre, et Université Paris-Saclay, Le Kremlin Bicêtre, France
| | - Benedetta Izzi
- Department of Cardiovascular SciencesCenter for Molecular and Vascular Biology, University of Leuven, Leuven, Belgium
| | - Olaf Hiort
- Division of Experimental Pediatric Endocrinology and DiabetesDepartment of Pediatrics, University of Lübeck, Lübeck, Germany
| | - Beatriz Lecumberri
- Department of Endocrinology and NutritionLa Paz University Hospital, Madrid, Spain
| | - Arrate Pereda
- Molecular (Epi)Genetics LaboratoryBioAraba National Health Institute, OSI Araba University Hospital, Vitoria-Gasteiz, Spain
- Department of Biochemistry and Molecular BiologyUniversity of Basque Country, Leioa, Spain
| | - Vrinda Saraff
- Department of Endocrinology and DiabetesBirmingham Children's Hospital, Birmingham, UK
| | - Caroline Silve
- APHPReference Center for rare disorders of the Calcium and Phosphate Metabolism, filière OSCAR and Plateforme d'Expertise Maladies Rares Paris-Sud, Hôpital Bicêtre Paris Sud, Le Kremlin Bicêtre, France
- INSERM U1169Hôpital Bicêtre, Le Kremlin Bicêtre, et Université Paris-Saclay, Le Kremlin Bicêtre, France
- APHPService de Biochimie et Génétique Moléculaires, Hôpital Cochin, Paris, France
| | - Serap Turan
- Department of PediatricsDivision of Endocrinology and Diabetes, Marmara University, Istanbul, Turkey
| | - Alessia Usardi
- APHPReference Center for rare disorders of the Calcium and Phosphate Metabolism, filière OSCAR and Plateforme d'Expertise Maladies Rares Paris-Sud, Hôpital Bicêtre Paris Sud, Le Kremlin Bicêtre, France
- APHPDepartment of Paediatric Endocrinology and Diabetology, Bicêtre Paris Sud hospital, Le Kremlin Bicêtre, France
| | - Ralf Werner
- Division of Experimental Pediatric Endocrinology and DiabetesDepartment of Pediatrics, University of Lübeck, Lübeck, Germany
| | - Guiomar Perez de Nanclares
- Molecular (Epi)Genetics LaboratoryBioAraba National Health Institute, OSI Araba University Hospital, Vitoria-Gasteiz, Spain
| | - Agnès Linglart
- APHPReference Center for rare disorders of the Calcium and Phosphate Metabolism, filière OSCAR and Plateforme d'Expertise Maladies Rares Paris-Sud, Hôpital Bicêtre Paris Sud, Le Kremlin Bicêtre, France
- INSERM U1169Hôpital Bicêtre, Le Kremlin Bicêtre, et Université Paris-Saclay, Le Kremlin Bicêtre, France
- APHPDepartment of Paediatric Endocrinology and Diabetology, Bicêtre Paris Sud hospital, Le Kremlin Bicêtre, France
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Mantovani G, Spada A, Elli FM. Pseudohypoparathyroidism and Gsα-cAMP-linked disorders: current view and open issues. Nat Rev Endocrinol 2016; 12:347-56. [PMID: 27109785 DOI: 10.1038/nrendo.2016.52] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Pseudohypoparathyroidism exemplifies an unusual form of hormone resistance as the underlying molecular defect is a partial deficiency of the α subunit of the stimulatory G protein (Gsα), a key regulator of the cAMP signalling pathway, rather than of the parathyroid hormone (PTH) receptor itself. Despite the first description of this disorder dating back to 1942, later findings have unveiled complex epigenetic alterations in addition to classic mutations in GNAS underpining the molecular basis of the main subtypes of pseudohypoparathyroidism. Moreover, mutations in PRKAR1A and PDE4D, which encode proteins crucial for Gsα-cAMP-mediated signalling, have been found in patients with acrodysostosis. As acrodysostosis, a disease characterized by skeletal malformations and endocrine disturbances, shares clinical and molecular characteristics with pseudohypoparathyroidism, making a differential diagnosis and providing genetic counselling to patients and families is a challenge for endocrinologists. Accumulating data on the genetic and clinical aspects of this group of diseases highlight the limitation of the current classification system and prompt the need for a new definition as well as for new diagnostic and/or therapeutic algorithms. This Review discusses both the current understanding and future challenges for the clinical and molecular diagnosis, classification and treatment of pseudohypoparathyroidism.
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MESH Headings
- Bone Diseases, Metabolic/diagnosis
- Bone Diseases, Metabolic/genetics
- Chromogranins/genetics
- Chromosome Deletion
- Chromosomes, Human, Pair 2/genetics
- Cyclic AMP
- Cyclic AMP-Dependent Protein Kinase RIalpha Subunit/genetics
- Cyclic Nucleotide Phosphodiesterases, Type 4/genetics
- Diagnosis, Differential
- Dysostoses/diagnosis
- Dysostoses/genetics
- Epigenesis, Genetic/genetics
- GTP-Binding Protein alpha Subunits, Gs/genetics
- Humans
- Intellectual Disability/diagnosis
- Intellectual Disability/genetics
- Ossification, Heterotopic/diagnosis
- Ossification, Heterotopic/genetics
- Osteochondrodysplasias/diagnosis
- Osteochondrodysplasias/genetics
- Pseudohypoparathyroidism/classification
- Pseudohypoparathyroidism/diagnosis
- Pseudohypoparathyroidism/genetics
- Signal Transduction
- Skin Diseases, Genetic/diagnosis
- Skin Diseases, Genetic/genetics
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Affiliation(s)
- Giovanna Mantovani
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Endocrinology Unit, Department of Clinical Sciences and Community Health, University of Milan, Via Francesco Sforza 35, Milan 20122, Italy
| | - Anna Spada
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Endocrinology Unit, Department of Clinical Sciences and Community Health, University of Milan, Via Francesco Sforza 35, Milan 20122, Italy
| | - Francesca Marta Elli
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Endocrinology Unit, Department of Clinical Sciences and Community Health, University of Milan, Via Francesco Sforza 35, Milan 20122, Italy
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Happle R. Progressive osseous heteroplasia is not a Mendelian trait but a type 2 segmental manifestation of GNAS inactivation disorders: A hypothesis. Eur J Med Genet 2016; 59:290-4. [PMID: 27058263 DOI: 10.1016/j.ejmg.2016.04.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Revised: 03/31/2016] [Accepted: 04/01/2016] [Indexed: 12/30/2022]
Abstract
Progressive osseous heteroplasia (POH) is a segmental disorder characterized by progressive heterotopic ossification that extends from dermal and subcutaneous tissues to deeper structures. So far, it has been taken as a rarely occurring bone disease with autosomal dominant inheritance. Here, arguments are presented in favor of the alternative concept that the disorder is merely a type 2 segmental manifestation of autosomal dominant GNAS inactivation disorders. Type 2 segmental mosaicism arises, in a heterozygous embryo, from a somatic mutational event that occurs at an early developmental stage, resulting in loss of the corresponding wild-type allele and giving rise to a homozygous or hemizygous cell clone. As a characteristic feature, such type 2 segmental involvement is far more pronounced than the type 1 segmental mosaicism as noted in otherwise healthy individuals. The concept of type 2 segmental mosaicism has been proven at the molecular level in six human traits including neurofibromatosis 1, Hailey-Hailey disease, and Gorlin syndrome. In POH, molecular proof of principle is so far lacking. The following lines of reasoning, however, support the hypothesis that POH can be explained by a similar mechanism. Firstly, POH has been found to be associated with different phenotypes caused by inactivating GNAS mutations, which is why it cannot be categorized as one distinct Mendelian trait. Secondly, POH occurs as a rather rare complication of these autosomal dominant traits, which is not compatible with the assumption of a separate Mendelian disorder. Thirdly, in a case of plate-like osteoma that represents a more superficial variant of POH, molecular proof of the concept of type 2 segmental manifestation has already been provided, and the available literature suggests that POH can be best explained by a similar mechanism. Moreover, findings obtained in animal experiments support the assumption that human POH represents such superimposed segmental manifestation of GNAS inactivation disorders.
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Affiliation(s)
- Rudolf Happle
- Department of Dermatology, Freiburg University Medical Center, Freiburg, Germany.
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28
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Lin MH, Numbenjapon N, Germain-Lee EL, Pitukcheewanont P. Progressive osseous heteroplasia, as an isolated entity or overlapping with Albright hereditary osteodystrophy. J Pediatr Endocrinol Metab 2015; 28:911-8. [PMID: 25894639 DOI: 10.1515/jpem-2014-0435] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Accepted: 02/11/2015] [Indexed: 11/15/2022]
Abstract
INTRODUCTION Progressive osseous heteroplasia (POH) is a condition of invasive heterotopic ossification. Reports of patients with mild POH with Albright hereditary osteodystrophy (AHO), specifically pseudohypoparathyroidism type Ia (PHP Ia) with hormonal resistance, suggest the possibility of a common molecular basis. GNAS has been implicated to account for overlapping features of POH and PHP Ia. Case 1: A 4-year-old boy with obesity, speech delay, and expanding subcutaneous masses on buttock/forearm. Physical exam revealed round facies and brachydactyly. Blood tests showed normal Ca, P, Mg, 25-OH vitamin D levels but elevated parathyroid hormone (PTH) and thyroid-stimulating hormone (TSH). Abdominal computed tomography (CT) showed areas with calcifications in the subcutaneous tissue, fat, and muscle. Pathology of excised tissue revealed ossifications. Genomic study revealed no GNAS mutation. He had POH and PHP Ia. Case 2: A 3-year-old boy with painful ossifications in the left lower extremity. Lab tests were notable for elevated PTH and high-normal TSH. The CT-scan showed subcutaneous/intramuscular calcifications. Genetic testing showed GNAS mutation in exon 12 [c.1024C>T (R342X)]. Patient had POH and PHP Ia. Case 3: A 9-year-old boy with knee pain and subcutaneous ossifications in back and upper/lower extremity, causing significantly limited joint mobility. Lab tests were normal. The CT-scan showed areas corresponding to subcutaneous/intramuscular ossifications throughout torso and extremities, consistent with POH. There was no GNAS mutation. CONCLUSIONS Patients with heterotopic ossifications present with a wide spectrum of disease. Although GNAS-based mutations have been postulated to account for overlapping features of AHO and POH, normal DNA studies in certain patients with POH/AHO suggest that there may exist other molecular/epigenetic mechanisms explaining their overlapping features.
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MESH Headings
- Bone Diseases, Metabolic/complications
- Bone Diseases, Metabolic/genetics
- Bone Diseases, Metabolic/pathology
- Child
- Child, Preschool
- Chromogranins
- GTP-Binding Protein alpha Subunits, Gs/genetics
- Humans
- Male
- Mutation/genetics
- Ossification, Heterotopic/complications
- Ossification, Heterotopic/genetics
- Ossification, Heterotopic/pathology
- Prognosis
- Pseudohypoparathyroidism/complications
- Pseudohypoparathyroidism/genetics
- Pseudohypoparathyroidism/pathology
- Skin Diseases, Genetic/complications
- Skin Diseases, Genetic/genetics
- Skin Diseases, Genetic/pathology
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Abstract
The Hedgehog (Hh) signalling pathway plays many important roles in development, homeostasis and tumorigenesis. The critical function of Hh signalling in bone formation has been identified in the past two decades. Here, we review the evolutionarily conserved Hh signalling mechanisms with an emphasis on the functions of the Hh signalling pathway in bone development, homeostasis and diseases. In the early stages of embryonic limb development, Sonic Hedgehog (Shh) acts as a major morphogen in patterning the limb buds. Indian Hedgehog (Ihh) has an essential function in endochondral ossification and induces osteoblast differentiation in the perichondrium. Hh signalling is also involved intramembrane ossification. Interactions between Hh and Wnt signalling regulate cartilage development, endochondral bone formation and synovial joint formation. Hh also plays an important role in bone homeostasis, and reducing Hh signalling protects against age-related bone loss. Disruption of Hh signalling regulation leads to multiple bone diseases, such as progressive osseous heteroplasia. Therefore, understanding the signalling mechanisms and functions of Hh signalling in bone development, homeostasis and diseases will provide important insights into bone disease prevention, diagnoses and therapeutics.
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30
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Pignolo RJ, Ramaswamy G, Fong JT, Shore EM, Kaplan FS. Progressive osseous heteroplasia: diagnosis, treatment, and prognosis. APPLICATION OF CLINICAL GENETICS 2015; 8:37-48. [PMID: 25674011 PMCID: PMC4321643 DOI: 10.2147/tacg.s51064] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Progressive osseous heteroplasia (POH) is an ultrarare genetic condition of progressive ectopic ossification. Most cases of POH are caused by heterozygous inactivating mutations of GNAS, the gene encoding the alpha subunit of the G-stimulatory protein of adenylyl cyclase. POH is part of a spectrum of related genetic disorders, including Albright hereditary osteodystrophy, pseudohypoparathyroidism, and primary osteoma cutis, that share common features of superficial ossification and association with inactivating mutations of GNAS. The genetics, diagnostic criteria, supporting clinical features, current management, and prognosis of POH are reviewed here, and emerging therapeutic strategies are discussed.
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Affiliation(s)
- Robert J Pignolo
- Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA ; Department of Orthopaedic Surgery, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA ; The Center for Research in FOP and Related Disorders, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Girish Ramaswamy
- Department of Orthopaedic Surgery, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA ; The Center for Research in FOP and Related Disorders, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - John T Fong
- Department of Orthopaedic Surgery, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA ; The Center for Research in FOP and Related Disorders, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Eileen M Shore
- Department of Orthopaedic Surgery, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA ; The Center for Research in FOP and Related Disorders, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA ; Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Frederick S Kaplan
- Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA ; Department of Orthopaedic Surgery, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA ; The Center for Research in FOP and Related Disorders, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
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31
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Mitsui T, Kim OH, Hall CM, Offiah A, Johnson D, Jin DK, Toh TH, Soneda S, Keino D, Matsubayashi S, Ishii T, Nishimura G, Hasegawa T. Acroscyphodysplasia as a phenotypic variation of pseudohypoparathyroidism and acrodysostosis type 2. Am J Med Genet A 2014; 164A:2529-34. [PMID: 25044890 DOI: 10.1002/ajmg.a.36669] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2014] [Accepted: 05/03/2014] [Indexed: 11/08/2022]
Abstract
Acroscyphodysplasia (OMIM250215) is a distinctive form of metaphyseal dysplasia characterized by the distal femoral and proximal tibial epiphyses embedded in cup-shaped, large metaphyses known as metaphyseal scypho ("scypho" = cup) deformity. It is also associated with severe growth retardation and brachydactyly. The underlying molecular mechanism of acroscyphodysplasia has not yet been elucidated, although scypho-deformity of the knee has been reported in three patients with acrodysostosis due to a mutation in the PDE4D gene. We report on the clinical, radiological, and molecular findings of five female patients with acroscyphodysplasia; two were diagnosed as pseudohypoparathyroidism (PHP) or Albright hereditary osteodystropy, and the other three as acrodysostosis. They all had radiological findings consistent with severe metaphyseal scypho-deformity and brachydactyly. Heterozygous mutations were identified in the PHP patients consisting of one novel (p.Q19X) and one recurrent (p.R231C) mutation of the GNAS gene, as well as, in the acrodysostosis patients consisting of two novel mutations (p.T224I and p.I333T) of the PDE4D gene. We conclude that metaphyseal acroscyphodysplasia is a phenotypic variation of PHP or acrodysostosis caused by either a GNAS or PDE4D mutation, respectively.
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Affiliation(s)
- Toshikatsu Mitsui
- Department of Pediatrics, School of Medicine, Keio University, Tokyo, Japan
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32
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Elli FM, Barbieri AM, Bordogna P, Ferrari P, Bufo R, Ferrante E, Giardino E, Beck-Peccoz P, Spada A, Mantovani G. Screening for GNAS genetic and epigenetic alterations in progressive osseous heteroplasia: first Italian series. Bone 2013; 56:276-80. [PMID: 23796510 DOI: 10.1016/j.bone.2013.06.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Revised: 06/13/2013] [Accepted: 06/14/2013] [Indexed: 01/16/2023]
Abstract
Progressive osseous heteroplasia (POH) is a rare autosomal dominant disorder of mesenchymal differentiation characterized by progressive heterotopic ossification (HO) of dermis, deep connective tissues and skeletal muscle. Usually, initial bone formation occurs during infancy as primary osteoma cutis (OC) then progressively extending into deep connective tissues and skeletal muscle over childhood. Most cases of POH are caused by paternally inherited inactivating mutations of GNAS gene. Maternally inherited mutations as well as epigenetic defects of the same gene lead to pseudohypoparathyroidism (PHP) and Albright's hereditary osteodystrophy (AHO). During the last decade, some reports documented the existence of patients with POH showing additional features characteristic of AHO such as short stature and brachydactyly, previously thought to occur only in other GNAS-associated disorders. Thus, POH can now be considered as part of a wide spectrum of ectopic bone formation disorders caused by inactivating GNAS mutations. Here, we report genetic and epigenetic analyses of GNAS locus in 10 patients affected with POH or primary OC, further expanding the spectrum of mutations associated with this rare disease and indicating that, unlike PHP, methylation alterations at the same locus are absent or uncommon in this disorder.
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Affiliation(s)
- F M Elli
- Department of Clinical Sciences and Community Health, University of Milan, Endocrinology and Diabetology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, via F. Sforza 35, 20122 Milano, Italy
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Activation of Hedgehog signaling by loss of GNAS causes heterotopic ossification. Nat Med 2013; 19:1505-12. [PMID: 24076664 PMCID: PMC3917515 DOI: 10.1038/nm.3314] [Citation(s) in RCA: 158] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Accepted: 07/19/2013] [Indexed: 12/17/2022]
Abstract
Bone formation is exquisitely controlled in space and time. Heterotopic ossification (HO), the pathologic formation of extra-skeletal bone, occurs as a common complication of trauma or in genetic disorders and can be disabling and lethal. However, the underlying molecular mechanisms are largely unknown. Here we demonstrate that Gαs restricts bone formation to the skeleton by inhibiting Hedgehog (Hh) signaling in mesenchymal progenitor cells. In progressive osseous heteroplasia (POH), a human disease caused by null mutations in GNAS that encodes Gαs, HH signaling is upregulated in ectopic osteoblasts and progenitor cells. Ectopic Hh signaling is sufficient to induce HO, while Hh signaling inhibition blocks HO in animal models. As our previous work has shown that GNAS gain of function mutations upregulate WNT/β-Catenin signaling in fibrous dysplasia (FD), our findings identify Gαs as a critical regulator of osteoblast differentiation by maintaining a balance between two key signaling pathways: Wnt/β-catenin and Hh. HH signaling inhibitors developed for cancer therapy may be repurposed to treat HO and other diseases caused by GNAS inactivation.
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34
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Gimble JM, Bunnell BA, Frazier T, Rowan B, Shah F, Thomas-Porch C, Wu X. Adipose-derived stromal/stem cells: a primer. Organogenesis 2013; 9:3-10. [PMID: 23538753 DOI: 10.4161/org.24279] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Until recently, the complexity of adipose tissue and its physiological role was not well appreciated. This changed with the discovery of adipokines such as leptin. The cellular composition of adipose tissue is heterogeneous and changes as a function of diabetes and disease states such as diabetes. Tissue engineers view adipose tissue as a rich source of adult stromal/stem cells isolated by collagenase digestion. In vitro and in vivo studies have documented that adipose stromal/stem cells are multipotent, with the ability to differentiate along the adipocyte, chondrocyte, osteoblast and other lineage pathways. The adipose stromal/stem cells secrete a wide range of cytokines and growth factors with potential paracrine actions. Furthermore, adipose stromal/stem cells exert immunomodulatory functions when added to mixed lymphocyte reactions, suggesting that they can be transplanted allogeneically. This review article focuses on these mechanisms of adipose stromal/stem cell action and their potential utility as cellular therapeutics.
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Affiliation(s)
- Jeffrey M Gimble
- Stem Cell Biology Laboratory, Pennington Biomedical Research Center, Baton Rouge, LA, USA
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Cheeseman MT, Vowell K, Hough TA, Jones L, Pathak P, Tyrer HE, Kelly M, Cox R, Warren MV, Peters J. A mouse model for osseous heteroplasia. PLoS One 2012; 7:e51835. [PMID: 23284784 PMCID: PMC3526487 DOI: 10.1371/journal.pone.0051835] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Accepted: 11/07/2012] [Indexed: 11/29/2022] Open
Abstract
GNAS/Gnas encodes Gsα that is mainly biallelically expressed but shows imprinted expression in some tissues. In Albright Hereditary Osteodystrophy (AHO) heterozygous loss of function mutations of GNAS can result in ectopic ossification that tends to be superficial and attributable to haploinsufficiency of biallelically expressed Gsα. Oed-Sml is a point missense mutation in exon 6 of the orthologous mouse locus Gnas. We report here both the late onset ossification and occurrence of benign cutaneous fibroepithelial polyps in Oed-Sml. These phenotypes are seen on both maternal and paternal inheritance of the mutant allele and are therefore due to an effect on biallelically expressed Gsα. The ossification is confined to subcutaneous tissues and so resembles the ossification observed with AHO. Our mouse model is the first with both subcutaneous ossification and fibroepithelial polyps related to Gsα deficiency. It is also the first mouse model described with a clinically relevant phenotype associated with a point mutation in Gsα and may be useful in investigations of the mechanisms of heterotopic bone formation. Together with earlier results, our findings indicate that Gsα signalling pathways play a vital role in repressing ectopic bone formation.
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Affiliation(s)
- Michael T Cheeseman
- Medical Research Council Mammalian Genetics Unit, Medical Research Council Harwell, Oxfordshire, UK.
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Abstract
CONTEXT The term pseudohypoparathyroidism (PHP) indicates a group of heterogeneous disorders whose common feature is represented by impaired signaling of various hormones (primarily PTH) that activate cAMP-dependent pathways via Gsα protein. The two main subtypes of PHP, PHP type Ia, and Ib (PHP-Ia, PHP-Ib) are caused by molecular alterations within or upstream of the imprinted GNAS gene, which encodes Gsα and other translated and untranslated products. EVIDENCE ACQUISITION A PubMed search was used to identify the available studies (main query terms: pseudohypoparathyroidism; Albright hereditary osteodystrophy; GNAS; GNAS1; progressive osseous heteroplasia). The most relevant studies until February 2011 have been included in the review. EVIDENCE SYNTHESIS AND CONCLUSIONS Despite the first description of this disorder dates back to 1942, recent findings indicating complex epigenetic alterations beside classical mutations at the GNAS complex gene, pointed out the limitation of the actual classification of the disease, resulting in incorrect genetic counselling and diagnostic procedures, as well as the gap in our actual knowledge of the pathogenesis of these disorders. This review will focus on PHP type I, in particular its diagnosis, classification, treatment, and underlying molecular alterations.
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Affiliation(s)
- Giovanna Mantovani
- Endocrinology and Diabetology Unit, Department of Medical Sciences, Università degli Studi di Milano, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico Ca' Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy.
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Bastepe M. The GNAS Locus: Quintessential Complex Gene Encoding Gsalpha, XLalphas, and other Imprinted Transcripts. Curr Genomics 2011; 8:398-414. [PMID: 19412439 PMCID: PMC2671723 DOI: 10.2174/138920207783406488] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2007] [Revised: 09/22/2007] [Accepted: 09/28/2007] [Indexed: 12/14/2022] Open
Abstract
The currently estimated number of genes in the human genome is much smaller than previously predicted. As an explanation for this disparity, most individual genes have multiple transcriptional units that represent a variety of biologically important gene products. GNAS exemplifies a gene of such complexity. One of its products is the alpha-subunit of the stimulatory heterotrimeric G protein (Gsalpha), a ubiquitous signaling protein essential for numerous different cellular responses. Loss-of-function and gain-of-function mutations within Gsalpha-coding GNAS exons are found in various human disorders, including Albright's hereditary osteodystrophy, pseudohypoparathyroidism, fibrous dysplasia of bone, and some tumors of different origin. While Gsalpha expression in most tissues is biallelic, paternal Gsalpha expression is silenced in a small number of tissues, playing an important role in the development of phenotypes associated with GNAS mutations. Additional products derived exclusively from the paternal GNAS allele include XLalphas, a protein partially identical to Gsalpha, and two non-coding RNA molecules, the A/B transcript and the antisense transcript. The maternal GNAS allele leads to NESP55, a chromogranin-like neuroendocrine secretory protein. In vivo animal models have demonstrated the importance of each of the exclusively imprinted GNAS products in normal mammalian physiology. However, although one or more of these products are also disrupted by most naturally occurring GNAS mutations, their roles in disease pathogenesis remain unknown. To further our understanding of the significance of this gene in physiology and pathophysiology, it will be important to elucidate the cellular roles and the mechanisms regulating the expression of each GNAS product.
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Affiliation(s)
- Murat Bastepe
- Endocrine Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
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Huso DL, Edie S, Levine MA, Schwindinger W, Wang Y, Jüppner H, Germain-Lee EL. Heterotopic ossifications in a mouse model of albright hereditary osteodystrophy. PLoS One 2011; 6:e21755. [PMID: 21747923 PMCID: PMC3126840 DOI: 10.1371/journal.pone.0021755] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2011] [Accepted: 06/06/2011] [Indexed: 11/22/2022] Open
Abstract
Albright hereditary osteodystrophy (AHO) is characterized by short stature, brachydactyly, and often heterotopic ossifications that are typically subcutaneous. Subcutaneous ossifications (SCO) cause considerable morbidity in AHO with no effective treatment. AHO is caused by heterozygous inactivating mutations in those GNAS exons encoding the α-subunit of the stimulatory G protein (Gα(s)). When inherited maternally, these mutations are associated with obesity, cognitive impairment, and resistance to certain hormones that mediate their actions through G protein-coupled receptors, a condition termed pseudohypoparathyroidism type 1a (PHP1a). When inherited paternally, GNAS mutations cause only AHO but not hormonal resistance, termed pseudopseudohypoparathyroidism (PPHP). Mice with targeted disruption of exon 1 of Gnas (Gnas(E1-/+)) replicate human PHP1a or PPHP phenotypically and hormonally. However, SCO have not yet been reported in Gnas(E1+/-) mice, at least not those that had been analyzed by us up to 3 months of age. Here we now show that Gnas(E1-/+) animals develop SCO over time. The ossified lesions increase in number and size and are uniformly detected in adult mice by one year of age. They are located in both the dermis, often in perifollicular areas, and the subcutis. These lesions are particularly prominent in skin prone to injury or pressure. The SCO comprise mature bone with evidence of mineral deposition and bone marrow elements. Superficial localization was confirmed by radiographic and computerized tomographic imaging. In situ hybridization of SCO lesions were positive for both osteonectin and osteopontin. Notably, the ossifications were much more extensive in males than females. Because Gnas(E1-/+) mice develop SCO features that are similar to those observed in AHO patients, these animals provide a model system suitable for investigating pathogenic mechanisms involved in SCO formation and for developing novel therapeutics for heterotopic bone formation. Moreover, these mice provide a model with which to investigate the regulatory mechanisms of bone formation.
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Affiliation(s)
- David L. Huso
- Department of Molecular and Comparative Pathobiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Sarah Edie
- Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Michael A. Levine
- Division of Endocrinology and Diabetes, The Children's Hospital of Philadelphia, and Department of Pediatrics, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - William Schwindinger
- Weis Center for Research, Geisinger Clinic, Danville, Pennsylvania, United States of America
| | - Yingli Wang
- Department of Genetics and Genomic Sciences, Mount Sinai School of Medicine, New York, New York, United States of America
| | - Harald Jüppner
- Endocrine Unit, Massachusetts General Hospital, Boston, Massachusetts, United States of America
- Pediatric Nephrology Unit, Massachusetts General Hospital, and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Emily L. Germain-Lee
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- Albright Clinic, Kennedy Krieger Institute, Baltimore, Maryland, United States of America
- Hugo W. Moser Research Institute at Kennedy Krieger, Baltimore, Maryland, United States of America
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de Arriba Muñoz A, Labarta Aizpún J, Dehesa EM, Calvo M, Pérez de Nanclares G, Ferrández-Longás A. Diferente expresividad de la mutacion Asn264LysfsX35 del gen GNAS en una familia afecta de pseudohipoparatiroidismo. An Pediatr (Barc) 2011; 74:116-21. [DOI: 10.1016/j.anpedi.2010.09.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Revised: 09/21/2010] [Accepted: 09/22/2010] [Indexed: 11/29/2022] Open
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Whyte MP, Kempa LG, McAlister WH, Zhang F, Mumm S, Wenkert D. Elevated serum lactate dehydrogenase isoenzymes and aspartate transaminase distinguish Albers-Schönberg disease (Chloride Channel 7 Deficiency Osteopetrosis) among the sclerosing bone disorders. J Bone Miner Res 2010; 25:2515-26. [PMID: 20499337 DOI: 10.1002/jbmr.130] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Osteopetrosis (OPT) refers to the consequences of generalized failure of skeletal resorption during growth. Most cases are explained by loss-of-function mutation within the genes that encode either chloride channel 7 (CLCN7) or a vacuolar proton pump subunit (TCIRG1), each compromising acid secretion by osteoclasts. Patients suffer fractures and sometimes cranial nerve entrapment and insufficient medullary space for hematopoiesis. In 1996, we reported that a high serum level of the brain isoenzyme of creatine kinase (BB-CK), the CK of osteoclasts, characterizes OPT dueamong the sclerosing bone disorders (J Clin Endocrinol Metab. 1996;11:1438). Now, we show that elevation in serum of multiple lactate dehydrogenase (LDH) isoenzymes with aspartate transaminase (AST) distinguishes autosomal dominant OPT due to loss-of-function mutation in CLCN7 [Albers-Schönberg disease (A-SD)] among these conditions. Serum total LDH and AST levels as high as 3× and 2×, respectively, the upper limits of normal for age-appropriate controls, were persistent and essentially concordant in A-SD. Serum LDH was elevated in 7 of 9 children and in the 2 adults studied with A-SD. LDH isoenzyme quantitation showed excesses of LDH-2, -3, and -4. Neither total LDH nor AST increases were found in other forms of OPT, including bisphosphonate-induced OPT, or in 41 children and 6 adults representing 20 additional sclerosing bone disorders. Serum TRACP-5b and BB-CK also were markedly elevated in A-SD. Hence, high serum levels of several enzymes characterize A-SD. Elevated serum LDH isoenzymes and AST indicate a disturbance (of uncertain clinical significance) within multiple extraosseous tissues when there is CLCN7 deficiency.
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Affiliation(s)
- Michael P Whyte
- Center for Metabolic Bone Disease and Molecular Research, Shriners Hospital for Children, St Louis, MO 63131-3597, USA.
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41
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Shore EM, Kaplan FS. Inherited human diseases of heterotopic bone formation. Nat Rev Rheumatol 2010; 6:518-27. [PMID: 20703219 DOI: 10.1038/nrrheum.2010.122] [Citation(s) in RCA: 183] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Human disorders of hereditary and nonhereditary heterotopic ossification are conditions in which osteogenesis occurs outside of the skeleton, within soft tissues of the body. The resulting extraskeletal bone is normal. The aberration lies within the mechanisms that regulate cell-fate determination, directing the inappropriate formation of cartilage or bone, or both, in tissues such as skeletal muscle and adipose tissue. Specific gene mutations have been identified in two rare inherited disorders that are clinically characterized by extensive and progressive extraskeletal bone formation-fibrodysplasia ossificans progressiva and progressive osseous heteroplasia. In fibrodysplasia ossificans progressiva, activating mutations in activin receptor type-1, a bone morphogenetic protein type I receptor, induce heterotopic endochondral ossification, which results in the development of a functional bone organ system that includes skeletal-like bone and bone marrow. In progressive osseous heteroplasia, the heterotopic ossification leads to the formation of mainly intramembranous bone tissue in response to inactivating mutations in the GNAS gene. Patients with these diseases variably show malformation of normal skeletal elements, identifying the causative genes and their associated signaling pathways as key mediators of skeletal development in addition to regulating cell-fate decisions by adult stem cells.
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Affiliation(s)
- Eileen M Shore
- Department of Orthopedic Surgery, University of Pennsylvania School of Medicine, 424 Stemmler Hall, 3450 Hamilton Walk, Philadelphia, PA 19104-6081, USA.
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Lebrun M, Richard N, Abeguilé G, David A, Coëslier Dieux A, Journel H, Lacombe D, Pinto G, Odent S, Salles JP, Taieb A, Gandon-Laloum S, Kottler ML. Progressive osseous heteroplasia: a model for the imprinting effects of GNAS inactivating mutations in humans. J Clin Endocrinol Metab 2010; 95:3028-38. [PMID: 20427508 DOI: 10.1210/jc.2009-1451] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Heterozygous GNAS inactivating mutations are known to induce pseudohypoparathyroidism type 1a when maternally inherited and pseudopseudohypoparathyroidism when paternally inherited. Progressive osseous heteroplasia (POH) is a rare disease of ectopic bone formation, and studies in different families have shown that POH is also caused by paternally inherited GNAS mutations. OBJECTIVE Our purpose was to characterize parental origin of the mutated allele in de novo cases of POH and to draw phenotype/genotype correlations according to maternal or paternal transmission of a same GNAS mutation. DESIGN AND SETTING We conducted a retrospective study on patients addressed to our referral center for the rare diseases of calcium and phosphorus metabolism. PATIENTS AND METHODS We matched 10 cases of POH with cases of pseudohypoparathyroidism type 1a carrying the same GNAS mutations. MAIN OUTCOME MEASURES The parental origin of the mutated allele was studied using informative intragenic polymorphisms and subcloning of PCR products. RESULTS Paternal origin of GNAS mutations was clearly demonstrated in eight POH cases including one patient with mutation in exon 1. Genotype/phenotype analyses suggest that there is no direct correlation between the ossifying process and the position of the inactivating GNAS mutation. It is, however, more severe in patients in whom origin of the mutation is paternal. Severe intrauterine growth retardation was clearly evidenced in paternally inherited mutations. CONCLUSIONS Clinical heterogeneity makes genetic counseling a delicate matter, especially in which paternal inheritance is concerned because it can lead to either a mild expression of pseudopseudohypoparathyroidism or a severe expression of POH.
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Affiliation(s)
- M Lebrun
- Department of Genetics and Reproduction, University Hospital-Caen, 14033 Caen, France
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Bergwitz C, Banerjee S, Abu-Zahra H, Kaji H, Miyauchi A, Sugimoto T, Jüppner H. Defective O-glycosylation due to a novel homozygous S129P mutation is associated with lack of fibroblast growth factor 23 secretion and tumoral calcinosis. J Clin Endocrinol Metab 2009; 94:4267-74. [PMID: 19837926 PMCID: PMC2775647 DOI: 10.1210/jc.2009-0961] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND Homozygous mutations in fibroblast growth factor (FGF23) have recently been described as the genetic cause of one form of hyperphosphatemic tumoral calcinosis (HFTC). However, it remained unclear to date how these mutations lead to loss of biologically active FGF23 in the circulation. METHODS We here report a novel homozygous mutation, c.385T>C in FGF23 exon 2, which changes codon 129 from serine to proline (S129P) in a previously described individual affected by HFTC. The S129P mutation as well as two known FGF23 mutations, S71G and S129F, were introduced into an expression vector encoding wild-type (wt) human (h) FGF23 to yield [P129]hFGF23, [F129]hFGF23, and [G71]hFGF23; whole lysates, glycoprotein fractions, and conditioned media from HEK293 and COS-7 cells expressing these constructs were subjected to Western blot analysis using affinity-purified goat anti-hFGF23(51-69) and anti-hFGF23(206-222) antibodies. RESULTS We detected 25- and 32-kDa protein species in total lysates of HEK293 cells expressing wt-hFGF23. The 32-kDa band, representing O-glycosylated hFGF23, was not detectable in the glycoprotein fraction of lysates from HEK293 cells expressing [P129]hFGF23, and in comparison with wt-FGF23 only small amounts of [P129]hFGF23 were secreted into the medium. Similar results were obtained for cells expressing [G71]hFGF23 and [F129]hFGF23. CONCLUSION Our data for the first time directly show that FGF23 mutations associated with HFTC impair O-glycosylation in vitro resulting in poor secretion of the mutant hormone thereby explaining the characteristic hyperphosphatemic phenotype of homozygous carriers in vivo.
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Affiliation(s)
- Clemens Bergwitz
- Endocrine Unit, Massachusetts General Hospital, Boston, Massachusetts 02114, USA.
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Klaassens M, Blom EW, Schrander JJP, Ris-Stalpers C, Nieuwenhuijzen Kruseman AC, van Steensel MAM, Schrander-Stumpel CTRM. Unique skin changes in a case of Albright hereditary osteodystrophy caused by a rare GNAS1
mutation. Br J Dermatol 2009; 162:690-4. [PMID: 19863504 DOI: 10.1111/j.1365-2133.2009.09543.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- M Klaassens
- Department of Pediatrics, Maastricht University Medical Center, AZ Maastricht, The Netherlands
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Aydin C, Aytan N, Mahon MJ, Tawfeek HAW, Kowall NW, Dedeoglu A, Bastepe M. Extralarge XL(alpha)s (XXL(alpha)s), a variant of stimulatory G protein alpha-subunit (Gs(alpha)), is a distinct, membrane-anchored GNAS product that can mimic Gs(alpha). Endocrinology 2009; 150:3567-75. [PMID: 19423757 PMCID: PMC2717877 DOI: 10.1210/en.2009-0318] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
GNAS gives rise to multiple imprinted gene products, including the alpha-subunit of the stimulatory G protein (Gs(alpha)) and its variant XL(alpha)s. Based on genomic sequence, the translation of XL(alpha)s begins from the middle of a long open reading frame, suggesting the existence of an N-terminally extended variant termed extralarge XLalphas (XXL(alpha)s). Although XXL(alpha), like Gs(alpha) and XL(alpha)s, would be affected by most disease-causing GNAS mutations, its authenticity and biological significance remained unknown. Here we identified a mouse cDNA clone that comprises the entire open reading frame encoding XXL(alpha)s. Whereas XXL(alpha)s mRNA was readily detected in mouse heart by RT-PCR, it appeared virtually absent in insulinoma-derived INS-1 cells. By Northern blots and RT-PCR, XXL(alpha)s mRNA was detected primarily in the mouse brain, cerebellum, and spleen. Immunohistochemistry using a specific anti-XXL(alpha)s antibody demonstrated XXL(alpha)s protein in multiple brain areas, including dorsal hippocampus and cortex. In transfected cells, full-length human XXL(alpha)s was localized to the plasma membrane and mediated isoproterenol- and cholera toxin-stimulated cAMP accumulation. XXL(alpha)s-R844H, which bears a mutation analogous to that in the constitutively active Gs(alpha) mutant Gs(alpha)-R201H (gsp oncogene), displayed elevated basal signaling. However, unlike Gs(alpha)-R201H, which mostly remains in the cytoplasm, both XXL(alpha)s-R844H and a constitutively active XL(alpha)s mutant localized to the plasma membrane. Hence, XXL(alpha)s is a distinct GNAS product and can mimic Gs(alpha), but the constitutively active XXL(alpha)s and Gs(alpha) mutants differ from each other regarding subcellular targeting. Our findings suggest that XXL(alpha)s deficiency or hyperactivity may contribute to the pathogenesis of diseases caused by GNAS mutations.
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Affiliation(s)
- Cumhur Aydin
- Endocrine Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114, USA
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46
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Adegbite NS, Xu M, Kaplan FS, Shore EM, Pignolo RJ. Diagnostic and mutational spectrum of progressive osseous heteroplasia (POH) and other forms of GNAS-based heterotopic ossification. Am J Med Genet A 2008; 146A:1788-96. [PMID: 18553568 DOI: 10.1002/ajmg.a.32346] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Progressive osseous heteroplasia (POH) is a rare, disabling disease of heterotopic ossification (HO) that progresses from skin and subcutaneous tissues into deep skeletal muscle. POH occurs in the absence of multiple developmental features of Albright hereditary osteodystrophy (AHO) or hormone resistance, clinical manifestations that are also associated with GNAS inactivation. However, occasional patients with AHO and pseudohypoparathyroidism 1a/c (PHP1a/c; AHO features plus hormone resistance) have also been described who have progressive HO. This study was undertaken to define the diagnostic and mutational spectrum of POH and progressive disorders of HO, and to distinguish them from related disorders in which HO remains confined to the skin and subcutaneous tissues. We reviewed the charts of 111 individuals who had cutaneous and subcutaneous ossification. All patients were assessed for eight characteristics: age of onset of HO, presence and location of HO, depth of HO, type of HO, progression of HO, features of AHO, PTH resistance, and GNAS mutation analysis. We found, based on clinical criteria, that POH and progressive HO syndromes are at the severe end of a phenotypic spectrum of GNAS-inactivating conditions associated with extra-skeletal ossification. While most individuals with superficial or progressive ossification had mutations in GNAS, there were no specific genotype-phenotype correlations that distinguished the more progressive forms of HO (e.g., POH) from the non-progressive forms (osteoma cutis, AHO, and PHP1a/c).
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Affiliation(s)
- N S Adegbite
- Department of Orthopaedic Surgery, University of Pennsylvania, School of Medicine, Philadelphia, Pennsylvania 19104, USA
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Kumagai K, Motomura K, Egashira M, Tomita M, Suzuki M, Uetani M, Shindo H. A case of progressive osseous heteroplasia: a first case in Japan. Skeletal Radiol 2008; 37:563-7. [PMID: 18309480 DOI: 10.1007/s00256-008-0469-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2007] [Revised: 12/06/2007] [Accepted: 01/21/2008] [Indexed: 02/02/2023]
Abstract
Progressive osseous heteroplasia (POH) is a rare, hereditary, disorder (number 166350 in Mendelian Inheritance in Man), which was first identified in 1994 and is characterized by dermal ossification beginning in infancy as a result of increasing and extensive bone formation in deep muscle and fascia. We describe a boy with typical clinical, radiographic, and genetic features of POH. A nonsense mutation in exon 7 of the GNAS1 gene was identified in genomic DNA from the patient. No such case has been reported in East Asia or Japan before this patient.
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Affiliation(s)
- Kenji Kumagai
- Department of Orthopedic Surgery, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki City, Japan.
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49
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Bastepe M. The GNAS locus and pseudohypoparathyroidism. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2008; 626:27-40. [PMID: 18372789 DOI: 10.1007/978-0-387-77576-0_3] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Pseudohypoparathyroidism (PHP) is a disorder of end-organ resistance primarily affecting the actions of parathyroid hormone (PTH). Genetic defects associated with different forms of PHP involve the alpha-subunit of the stimulatory G protein (Gsalpha), a signaling protein essential for the actions of PTH and many other hormones. Heterozygous inactivating mutations within Gsalpha-encoding GNAS exons are found in patients with PHP-Ia, who also show resistance to other hormones and a constellation ofphysical features called Albright's hereditary osteodystrophy (AHO). Patients who exhibit AHO features without evidence for hormone resistance, who are said to have pseudopseudohypoparathyroidism (PPHP), also carry heterozygous inactivating Gsalpha mutations. Maternal inheritance of such a mutation leads to PHP-Ia, i.e., AHO plus hormone resistance, while paternal inheritance of the same mutation leads to PPHP, i.e., AHO only. This imprinted mode of inheritance for hormone resistance can be explained by the predominantly maternal expression of Gsalpha in certain tissues, including renal proximal tubules. Patients with PHP-Ib lack coding Gsalpha mutations but display epigenetic defects of the GNAS locus, with the most consistent defect being a loss of imprinting at the exon A/B differentially methylated region (DMR). This epigenetic defect presumably silences, in cis, Gsalpha expression in tissues where this protein is derived from the maternal allele only, leading to a marked reduction of Gsa levels. The familial form of PHP-Ib (AD-PHP-Ib) is typically associated with an isolated loss of imprinting at the exon A/B DMR. A unique 3-kb microdeletion that disrupts the neighboring STX16 1ocus has been identified in this disorder and appears to be the cause of the loss of imprinting. In addition, deletions removing the entire NESP55 DMR, located within GNAS, have been identified in some AD-PHP-Ib kindreds in whom affected individuals show loss of all the maternal GNAS imprints. Mutations identified in different forms of PHP-Ib thus point to different cis-acting elements that are apparently required for the proper imprinting of the GNAS locus. Most sporadic PHP-Ib cases also have imprinting abnormalities of GNAS that involve multiple DMRs, but the genetic lesion(s) responsible for these imprinting abnormalities remain to be discovered.
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Affiliation(s)
- Murat Bastepe
- Endocrine Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA.
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Kupitz S, Enoch S, Harding KG. Chronic ulcers, calcification and calcified fibrous tumours: phenotypic manifestations of a congenital disorder of heterotopic ossification. Int Wound J 2008; 4:273-80. [PMID: 17924883 DOI: 10.1111/j.1742-481x.2007.00301.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Calcification is a rarely reported cause for chronic, cutaneous ulceration. Although dystrophic calcification occurs in chronic ulcers, idiopathic calcification and ossification leading to recurrent ulcerations is seldom reported. This report illustrates a challenging case with various non healing wounds, calcification/ossification and calcified fibrous tumours. A 56-year-old woman presented with chronic, painful wounds and calcified deposits in her feet, hands and abdomen, some dating back to childhood. The surgeries she had had for various unrelated conditions healed with hard, calcified deposits, which later ulcerated. Skeletal radiological imaging revealed multiple soft-tissue deposits, with calcification and areas of ossification, along with gross distortion of the bony architecture of her feet. All biochemical investigations were normal apart from raised serum alkaline phosphatase. The management has encompassed a combination of conservative and surgical measures (culminating in a left below-knee amputation) with varying degrees of success. Having ruled out other causes of subcutaneous calcification, three congenital disorders of heterotopic ossification fit this patient's presentation: Albright hereditary osteodystrophy (AHO), fibrodysplasia ossificans progressiva (FOP) and progressive osseous heteroplasia (POH). Although AHO and FOP are possibilities, POH is most likely. In addition to describing the diverse phenotypic manifestations of this disorder, this report discusses the diagnostic dilemmas, difficulties in optimising the management plan and issues relating to health-related quality of life in this patient.
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Affiliation(s)
- Susanne Kupitz
- Department of Medicine, New Cross Hospital, Wolverhampton, England, UK
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