1
|
Mundy C, Chung J, Koyama E, Bunting S, Mahimkar R, Pacifici M. Osteochondroma formation is independent of heparanase expression as revealed in a mouse model of hereditary multiple exostoses. J Orthop Res 2022; 40:2391-2401. [PMID: 34996123 PMCID: PMC9259764 DOI: 10.1002/jor.25260] [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] [Received: 07/26/2021] [Revised: 12/20/2021] [Accepted: 01/05/2022] [Indexed: 02/04/2023]
Abstract
Hereditary multiple exostoses (HME) is a rare, pediatric disorder characterized by osteochondromas that form along growth plates and provoke significant musculoskeletal problems. HME is caused by mutations in heparan sulfate (HS)-synthesizing enzymes EXT1 or EXT2. Seemingly paradoxically, osteochondromas were found to contain excessive extracellular heparanase (Hpse) that could further reduce HS levels and exacerbate pathogenesis. To test Hpse roles, we asked whether its ablation would protect against osteochondroma formation in a conditional HME model consisting of mice bearing floxed Ext1 alleles in Agr-CreER background (Ext1f/f ;Agr-CreER mice). Mice were crossed with a new global Hpse-null (Hpse-/- ) mice to produce compound Hpse-/- ;Ext1f/f ;Agr-CreER mice. Tamoxifen injection of standard juvenile Ext1f/f ;Agr-CreER mice elicited stochastic Ext1 ablation in growth plate and perichondrium, followed by osteochondroma formation, as revealed by microcomputed tomography and histochemistry. When we examined companion conditional Ext1-deficient mice lacking Hpse also, we detected no major decreases in osteochondroma number, skeletal distribution, and overall structure by the analytical criteria above. The Ext1 mutants used here closely mimic human HME pathogenesis, but have not been previously tested for responsiveness to treatments. To exclude some innate therapeutic resistance in this stochastic model, tamoxifen-injected Ext1f/f ;Agr-CreER mice were administered daily doses of the retinoid Palovarotene, previously shown to prevent ectopic cartilage and bone formation in other mouse disease models. This treatment did inhibit osteochondroma formation compared with vehicle-treated mice. Our data indicate that heparanase is not a major factor in osteochondroma initiation and accumulation in mice. Possible roles of heparanase upregulation in disease severity in patients are discussed.
Collapse
Affiliation(s)
- Christina Mundy
- Translational Research Program in Pediatric Orthopaedics, Division of Orthopaedic Surgery, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Juliet Chung
- Translational Research Program in Pediatric Orthopaedics, Division of Orthopaedic Surgery, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Eiki Koyama
- Translational Research Program in Pediatric Orthopaedics, Division of Orthopaedic Surgery, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania
| | | | | | - Maurizio Pacifici
- Translational Research Program in Pediatric Orthopaedics, Division of Orthopaedic Surgery, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania
| |
Collapse
|
2
|
Bukowska-Olech E, Trzebiatowska W, Czech W, Drzymała O, Frąk P, Klarowski F, Kłusek P, Szwajkowska A, Jamsheer A. Hereditary Multiple Exostoses-A Review of the Molecular Background, Diagnostics, and Potential Therapeutic Strategies. Front Genet 2021; 12:759129. [PMID: 34956317 PMCID: PMC8704583 DOI: 10.3389/fgene.2021.759129] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Accepted: 11/08/2021] [Indexed: 11/17/2022] Open
Abstract
Hereditary multiple exostoses (HMEs) syndrome, also known as multiple osteochondromas, represents a rare and severe human skeletal disorder. The disease is characterized by multiple benign cartilage-capped bony outgrowths, termed exostoses or osteochondromas, that locate most commonly in the juxta-epiphyseal portions of long bones. Affected individuals usually complain of persistent pain caused by the pressure on neighboring tissues, disturbance of blood circulation, or rarely by spinal cord compression. However, the most severe complication of this condition is malignant transformation into chondrosarcoma, occurring in up to 3.9% of HMEs patients. The disease results mainly from heterozygous loss-of-function alterations in the EXT1 or EXT2 genes, encoding Golgi-associated glycosyltransferases, responsible for heparan sulfate biosynthesis. Some of the patients with HMEs do not carry pathogenic variants in those genes, hence the presence of somatic mutations, deep intronic variants, or another genes/loci is suggested. This review presents the systematic analysis of current cellular and molecular concepts of HMEs along with clinical characteristics, clinical and molecular diagnostic methods, differential diagnosis, and potential treatment options.
Collapse
Affiliation(s)
| | | | - Wiktor Czech
- Medical Student, Poznan University of Medical Sciences, Poznan, Poland
| | - Olga Drzymała
- Medical Student, Poznan University of Medical Sciences, Poznan, Poland
| | - Piotr Frąk
- Medical Student, Poznan University of Medical Sciences, Poznan, Poland
| | | | - Piotr Kłusek
- Medical Student, Poznan University of Medical Sciences, Poznan, Poland
| | - Anna Szwajkowska
- Medical Student, Poznan University of Medical Sciences, Poznan, Poland
| | - Aleksander Jamsheer
- Department of Medical Genetics, Poznan University of Medical Sciences, Poznan, Poland.,Centers for Medical Genetics GENESIS, Poznan, Poland
| |
Collapse
|
3
|
Kale SY, Gunjotikar AR, Sane RM, Singh S, Dhar SB, Patil RL. Osteochondroma Presenting Clinically with Carpal Tunnel Syndrome in a 12-Year-old Boy. J Orthop Case Rep 2021; 11:109-112. [PMID: 34557453 PMCID: PMC8422022 DOI: 10.13107/jocr.2021.v11.i05.2230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Introduction An exostosis is a benign growth of bone, which when capped with cartilage is called osteochondroma, which can appear as solitary or multiple, mostly affecting the long bones, pelvis, and shoulder region. The prevalence of known solitary exostosis is 1-2% in the general population. They are slow growing lesions with rare malignant transformation. In patients with a solitary exostosis, the chance of developing a chondrosarcoma out of an exostosis is around 1%. Case Report A 12-year-old boy presented to our outpatient department with complaints of pain, and swelling at the right wrist since 1 year and tingling numbness on and around palmar aspect of index and middle finger since 6 months. The swelling was of size 3 cm × 2 cm, Tinel's sign was positive. His blood parameters were normal. X-ray showed exostoses. Magnetic resonance imaging was suggestive of osteochondroma. Nerve conduction study was normal. Excision biopsy confirmed the diagnosis and also relieved all symptoms. Conclusion Our case report is unique in its own way as it reminds us that when presented with a case of osteochondroma of the distal radius in children, carpal tunnel syndrome can also occur.
Collapse
Affiliation(s)
- Sachin Yashwant Kale
- Department of Orthopaedics, D Y Patil University School of Medicine, Navi-Mumbai, Maharashtra. India
| | | | - Rohit Mahesh Sane
- Department of Orthopaedics, D Y Patil University School of Medicine, Navi-Mumbai, Maharashtra. India
| | - Sushmit Singh
- Department of Orthopaedics, D Y Patil University School of Medicine, Navi-Mumbai, Maharashtra. India
| | - Sanjay B Dhar
- Department of Orthopaedics, D Y Patil University School of Medicine, Navi-Mumbai, Maharashtra. India
| | - Raju Laxmanrao Patil
- Department of Orthopaedics, D Y Patil University School of Medicine, Navi-Mumbai, Maharashtra. India
| |
Collapse
|
4
|
Heparanase: A Potential Therapeutic Target in Sarcomas. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1221:405-431. [PMID: 32274719 DOI: 10.1007/978-3-030-34521-1_15] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Sarcomas comprise a heterogeneous group of rare malignancies of mesenchymal origin including more than 70 subtypes. They may arise in muscle, bone, cartilage and other connective tissues. Their high histological and genetic heterogeneity makes diagnosis and treatment very challenging. Deregulation of heparanase has been found in several sarcoma subtypes and high expression levels have been correlated with poor prognosis in Ewing's sarcoma and osteosarcoma. Altered expression of specific heparan sulfate proteoglycans and heparan sulfate biosynthetic enzymes has also been observed. Advances in molecular pathogenesis of sarcomas have evidenced the critical role of several heparan sulfate binding growth factors and receptor tyrosine kinases, highly interconnected with the microenvironment, in sustaining tumor growth and progression. Interference with heparanase/heparan sulfate functions represents a potential therapeutic approach in sarcoma. In this chapter, we summarize the current knowledge about the biological significance of heparanase expression and its potential as a therapeutic target in subtypes of both soft tissue and bone sarcomas. Particular emphasis is given to the involvement of heparan sulfate proteoglycans and their synthesizing and modifying enzymes in bone physiology and disorders leading up to the pathobiology of bone sarcomas. The chapter also describes the cooperation between exostin loss-of-function and heparanase upregulation in hereditary Multiple Osteochondroma syndrome as a paradigmatic example of constitutive alteration of the heparanase/heparan sulfate proteoglycan system which may contribute to progression to malignant secondary chondrosarcoma. Preclinical evidence of the role of heparanase as a promising therapeutic target in various sarcoma subtypes is finally resumed.
Collapse
|
5
|
Yang C, Zhang R, Lin H, Wang H. Insights into the molecular regulatory network of pathomechanisms in osteochondroma. J Cell Biochem 2019; 120:16362-16369. [PMID: 31211456 DOI: 10.1002/jcb.29155] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 05/17/2019] [Accepted: 05/22/2019] [Indexed: 12/21/2022]
Abstract
Osteochondroma is a benign autosomal dominant hereditary disease characterized by abnormal proliferation of cartilage in the long bone. It is divided into solitary osteochondroma and hereditary multiple exostoses (HMEs). The exostosin-1 (EXT-1) and exostosin-2 (EXT-2) gene mutations are well-defined molecular mechanisms in the pathogenesis of HME. EXT-1 and EXT-2 encode glycosyltransferases that are necessary for the synthesis of heparin sulfate. Accumulating evidence suggests that mutations in the EXT family induce changes in isolated hypogonadotropic hypogonadism-parathyroid hormone-related protein, bone morphogenetic protein, and fibroblast growth factor signaling pathways. Studies have also found that a large number of microRNAs (miRNAs) are abnormally expressed in osteochondroma tissues, and some of them also participate in several major signaling pathways. The regulation of miRNA expression could be another breakthrough in the treatment of osteochondroma. Although the pathogenesis of osteochondroma is very complicated, significant progress has been made in recent years. It is hoped that the pathogenesis of osteochondroma will be clearly understood and the most effective methods for the prevention and treatment of osteochondroma will be determined. This review provides an update on the recent progress in the interpretation of the underlying molecular mechanisms of osteochondroma.
Collapse
Affiliation(s)
- Congyi Yang
- School of Basic Medical Sciences, Nanchang University, Nanchang, Jiangxi, China.,Queen Mary School, Nanchang University, Nanchang, Jiangxi, China
| | - Ruiqian Zhang
- School of Basic Medical Sciences, Nanchang University, Nanchang, Jiangxi, China.,Queen Mary School, Nanchang University, Nanchang, Jiangxi, China
| | - Hui Lin
- School of Basic Medical Sciences, Nanchang University, Nanchang, Jiangxi, China
| | - Hongmei Wang
- School of Basic Medical Sciences, Nanchang University, Nanchang, Jiangxi, China
| |
Collapse
|
6
|
Veraldi N, Parra A, Urso E, Cosentino C, Locatelli M, Corsini S, Pedrini E, Naggi A, Bisio A, Sangiorgi L. Structural Features of Heparan Sulfate from Multiple Osteochondromas and Chondrosarcomas. Molecules 2018; 23:E3277. [PMID: 30544937 PMCID: PMC6321082 DOI: 10.3390/molecules23123277] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 11/23/2018] [Accepted: 12/06/2018] [Indexed: 12/29/2022] Open
Abstract
Multiple osteochondromas (MO) is a hereditary disorder associated with benign cartilaginous tumors, known to be characterized by absence or highly reduced amount of heparan sulfate (HS) in the extracellular matrix of growth plate cartilage, which alters proper signaling networks leading to improper bone growth. Although recent studies demonstrated accumulation of HS in the cytoplasm of MO chondrocytes, nothing is known on the structural alterations which prevent HS from undergoing its physiologic pathway. In this work, osteochondroma (OC), peripheral chondrosarcoma, and healthy cartilaginous human samples were processed following a procedure previously set up to structurally characterize and compare HS from pathologic and physiologic conditions, and to examine the phenotypic differences that arise in the presence of either exostosin 1 or 2 (EXT1 or EXT2) mutations. Our data suggest that HS chains from OCs are prevalently below 10 kDa and slightly more sulfated than healthy ones, whereas HS chains from peripheral chondrosarcomas (PCSs) are mostly higher than 10 kDa and remarkably more sulfated than all the other samples. Although deeper investigation is still necessary, the approach here applied pointed out, for the first time, structural differences among OC, PCS, and healthy HS chains extracted from human cartilaginous excisions, and could help in understanding how the structural features of HS are modulated in the presence of pathological situations also involving different tissues.
Collapse
Affiliation(s)
- Noemi Veraldi
- Istituto di Ricerche Chimiche e Biochimiche G. Ronzoni, V. G. Colombo 81, 20133 Milan, Italy.
| | - Alessandro Parra
- IRCCS-Istituto Ortopedico Rizzoli, V. di Barbiano 1/10, 40136 Bologna, Italy.
| | - Elena Urso
- Istituto di Ricerche Chimiche e Biochimiche G. Ronzoni, V. G. Colombo 81, 20133 Milan, Italy.
| | - Cesare Cosentino
- Istituto di Ricerche Chimiche e Biochimiche G. Ronzoni, V. G. Colombo 81, 20133 Milan, Italy.
| | - Manuela Locatelli
- Department of Medical Genetics and Rare Orthopaedic Diseases-IRCCS, Istituto Ortopedico Rizzoli, V. di Barbiano 1/10, 40136 Bologna, Italy.
| | - Serena Corsini
- Department of Medical Genetics and Rare Orthopaedic Diseases-IRCCS, Istituto Ortopedico Rizzoli, V. di Barbiano 1/10, 40136 Bologna, Italy.
| | - Elena Pedrini
- Department of Medical Genetics and Rare Orthopaedic Diseases-IRCCS, Istituto Ortopedico Rizzoli, V. di Barbiano 1/10, 40136 Bologna, Italy.
| | - Annamaria Naggi
- Istituto di Ricerche Chimiche e Biochimiche G. Ronzoni, V. G. Colombo 81, 20133 Milan, Italy.
| | - Antonella Bisio
- Istituto di Ricerche Chimiche e Biochimiche G. Ronzoni, V. G. Colombo 81, 20133 Milan, Italy.
| | - Luca Sangiorgi
- Department of Medical Genetics and Rare Orthopaedic Diseases & CLIBI Laboratory-IRCCS, Istituto Ortopedico Rizzoli, V. di Barbiano 1/10, 40136 Bologna, Italy.
| |
Collapse
|
7
|
Abstract
Introduction Hereditary multiple exostoses (HME) is a rare congenital pediatric disorder characterized by osteochondromas forming next to the growth plates in young patients. The osteochondromas cause multiple health problems that include skeletal deformities and chronic pain. Surgery is used to remove the most symptomatic osteochondromas but because of their large number, many are left in place, causing life-long problems and increasing the probability of malignant transformation. There is no other treatment to prevent or reduce osteochondromas formation at present. Areas covered Recent studies reviewable through PubMed are providing new insights into cellular and molecular mechanisms of osteochondroma development. The resulting data are suggesting rational and plausible new therapeutic strategies for osteochondroma prevention some of which are being tested in HME animal models and one of which is part of a just announced clinical trial. Expert Commentary This section summarizes and evaluates such strategies and points also to possible future alternatives.
Collapse
Affiliation(s)
- Maurizio Pacifici
- Translational Research Program in Pediatric Orthopaedics, Division of Orthopaedic Surgery, The Children's Hospital of Philadelphia, Philadelphia, PA 19104
| |
Collapse
|
8
|
Phan AQ, Pacifici M, Esko JD. Advances in the pathogenesis and possible treatments for multiple hereditary exostoses from the 2016 international MHE conference. Connect Tissue Res 2018; 59:85-98. [PMID: 29099240 PMCID: PMC7604901 DOI: 10.1080/03008207.2017.1394295] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Multiple hereditary exostoses (MHE) is an autosomal dominant disorder that affects about 1 in 50,000 children worldwide. MHE, also known as hereditary multiple exostoses (HME) or multiple osteochondromas (MO), is characterized by cartilage-capped outgrowths called osteochondromas that develop adjacent to the growth plates of skeletal elements in young patients. These benign tumors can affect growth plate function, leading to skeletal growth retardation, or deformations, and can encroach on nerves, tendons, muscles, and other surrounding tissues and cause motion impairment, chronic pain, and early onset osteoarthritis. In about 2-5% of patients, the osteochondromas can become malignant and life threatening. Current treatments consist of surgical removal of the most symptomatic tumors and correction of the major skeletal defects, but physical difficulties and chronic pain usually continue and patients may undergo multiple surgeries throughout life. Thus, there is an urgent need to find new treatments to prevent or reverse osteochondroma formation. The 2016 International MHE Research Conference was convened to provide a forum for the presentation of the most up-to-date and advanced clinical and basic science data and insights in MHE and related fields; to stimulate the forging of new perspectives, collaborations, and venues of research; and to publicize key scientific findings within the biomedical research community and share insights and relevant information with MHE patients and their families. This report provides a description, review, and assessment of all the exciting and promising studies presented at the Conference and delineates a general roadmap for future MHE research targets and goals.
Collapse
Affiliation(s)
- Anne Q. Phan
- Department of Cellular and Molecular Medicine, Glycobiology Research and Training Center, University of California, San Diego, La Jolla, CA, USA
| | - Maurizio Pacifici
- Translational Research Program in Pediatric Orthopaedics, Division of Orthopaedic Surgery, The Children’s Hospital of Philadelphia, Philadelphia, PA, USA
| | - Jeffrey D. Esko
- Department of Cellular and Molecular Medicine, Glycobiology Research and Training Center, University of California, San Diego, La Jolla, CA, USA
| |
Collapse
|
9
|
Pacifici M. The pathogenic roles of heparan sulfate deficiency in hereditary multiple exostoses. Matrix Biol 2017; 71-72:28-39. [PMID: 29277722 DOI: 10.1016/j.matbio.2017.12.011] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 12/19/2017] [Accepted: 12/19/2017] [Indexed: 12/20/2022]
Abstract
Heparan sulfate (HS) is an essential component of cell surface and matrix proteoglycans (HS-PGs) that include syndecans and perlecan. Because of their unique structural features, the HS chains are able to specifically interact with signaling proteins -including bone morphogenetic proteins (BMPs)- via their HS-binding domain, regulating protein availability, distribution and action on target cells. Hereditary Multiple Exostoses (HME) is a rare pediatric disorder linked to germline heterozygous loss-of-function mutations in EXT1 or EXT2 that encode Golgi-resident glycosyltransferases responsible for HS synthesis, resulting in a systemic HS deficiency. HME is characterized by cartilaginous/bony tumors -called osteochondromas or exostoses- that form within perichondrium in long bones, ribs and other elements. This review examines most recent studies in HME, framing them in the context of classic studies. New findings show that the spectrum of EXT mutations is larger than previously realized and the clinical complications of HME extend beyond the skeleton. Osteochondroma development requires a somatic "second hit" that would complement the germline EXT mutation to further decrease HS production and/levels at perichondrial sites of osteochondroma induction. Cellular studies have shown that the steep decreases in local HS levels: derange the normal homeostatic signaling pathways keeping perichondrium mesenchymal; cause excessive BMP signaling; and provoke ectopic chondrogenesis and osteochondroma formation. Data from HME mouse models have revealed that systemic treatment with a BMP signaling antagonist markedly reduces osteochondroma formation. In sum, recent studies have provided major new insights into the molecular and cellular pathogenesis of HME and the roles played by HS deficiency. These new insights have led to the first ever proof-of-principle demonstration that osteochondroma formation is a druggable process, paving the way toward the creation of a clinically-relevant treatment.
Collapse
Affiliation(s)
- Maurizio Pacifici
- Translational Research Program in Pediatric Orthopaedics, Division of Orthopaedic Surgery, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, United States.
| |
Collapse
|
10
|
Pacifici M. Hereditary Multiple Exostoses: New Insights into Pathogenesis, Clinical Complications, and Potential Treatments. Curr Osteoporos Rep 2017; 15:142-152. [PMID: 28466453 PMCID: PMC5510481 DOI: 10.1007/s11914-017-0355-2] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
PURPOSE OF REVIEW Hereditary multiple exostoses (HME) is a complex musculoskeletal pediatric disorder characterized by osteochondromas that form next to the growth plates of many skeletal elements, including long bones, ribs, and vertebrae. Due to its intricacies and unresolved issues, HME continues to pose major challenges to both clinicians and biomedical researchers. The purpose of this review is to describe and analyze recent advances in this field and point to possible targets and strategies for future biologically based therapeutic intervention. RECENT FINDINGS Most HME cases are linked to loss-of-function mutations in EXT1 or EXT2 that encode glycosyltransferases responsible for heparan sulfate (HS) synthesis, leading to HS deficiency. Recent genomic inquiries have extended those findings but have yet to provide a definitive genotype-phenotype correlation. Clinical studies emphasize that in addition to the well-known skeletal problems caused by osteochondromas, HME patients can experience, and suffer from, other symptoms and health complications such as chronic pain and nerve impingement. Laboratory work has produced novel insights into alterations in cellular and molecular mechanisms instigated by HS deficiency and subtending onset and growth of osteochondroma and how such changes could be targeted toward therapeutic ends. HME is a rare and orphan disease and, as such, is being studied only by a handful of clinical and basic investigators. Despite this limitation, significant advances have been made in the last few years, and the future bodes well for deciphering more thoroughly its pathogenesis and, in turn, identifying the most effective treatment for osteochondroma prevention.
Collapse
Affiliation(s)
- Maurizio Pacifici
- Translational Research Program in Pediatric Orthopaedics, Abramson Research Center, 902D, Division of Orthopaedic Surgery, Department of Surgery, The Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA.
| |
Collapse
|
11
|
Pääkkönen V, Saraniemi S, Bleicher F, Nevo Z, Tjäderhane L. Exostosin 1 is expressed in human odontoblasts. Arch Oral Biol 2017; 80:175-179. [PMID: 28448806 DOI: 10.1016/j.archoralbio.2017.04.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Revised: 03/31/2017] [Accepted: 04/06/2017] [Indexed: 11/18/2022]
Abstract
OBJECTIVE Dental pulp is soft connective tissue maintaining the vitality of the tooth, while odontoblasts form the dentin. Our earlier DNA microarray analysis revealed expression of putative tumour suppressor exostosin 1 (EXT-1) in odontoblasts. EXT-1 is essential for heparan sulphate synthesis, which may play a role in the dentin mineralization. Since the absence of the functional EXT-1 causes bone tumours, expression in odontoblasts is interesting. Our aim was to analyse further the EXT-1 expression in human tooth. DESIGNS DNA microarray and PCR techniques were used to study the EXT-1 expression in mature native human odontoblasts and pulp tissue as well as in newly-differentiated cultured odontoblast-like cells. Immunohistochemistry was performed to study EXT-1 protein in mature human teeth, teeth with incomplete root and developing teeth. RESULTS Markedly higher EXT-1 was observed in mature odontoblasts than in pulp at mRNA level with DNA microarray and PCR techniques. Immunohistochemistry of mature tooth revealed EXT-1 both in odontoblasts and the predentin but not in the dentin. EXT-1 was also observed in the odontoblasts of incomplete root, but the localization of the staining was different. In developing foetal tooth, staining was detected in ameloblasts and the basal lamina. CONCLUSIONS The detection of EXT-1 in both mature and newly-differentiated cells indicates a role in the odontoblast function, and EXT-1 staining in the predentin indicates a function in the dentin formation. Detection of EXT-1 in developing teeth indicates a role in tooth development.
Collapse
Affiliation(s)
- Virve Pääkkönen
- Research Unit of Oral Health Sciences, University of Oulu, Finland.
| | - Stina Saraniemi
- Research Unit of Oral Health Sciences, University of Oulu, Finland
| | - Françoise Bleicher
- Institut de Génomique Fonctionnelle de Lyon, F-69007, Lyon, >France; University of Lyon, F-69000, Lyon, France
| | - Zvi Nevo
- Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Ramat Aviv, Tel Aviv, Israel
| | - Leo Tjäderhane
- Research Unit of Oral Health Sciences, University of Oulu, Finland; Medical Research Center Oulu (MRC Oulu), Oulu University Hospital, Oulu, Finland; Department of Oral and Maxillofacial Diseases, University of Helsinki, and Helsinki University Hospital, Helsinki, Finland
| |
Collapse
|
12
|
Sinha S, Mundy C, Bechtold T, Sgariglia F, Ibrahim MM, Billings PC, Carroll K, Koyama E, Jones KB, Pacifici M. Unsuspected osteochondroma-like outgrowths in the cranial base of Hereditary Multiple Exostoses patients and modeling and treatment with a BMP antagonist in mice. PLoS Genet 2017; 13:e1006742. [PMID: 28445472 PMCID: PMC5425227 DOI: 10.1371/journal.pgen.1006742] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Revised: 05/10/2017] [Accepted: 04/05/2017] [Indexed: 11/18/2022] Open
Abstract
Hereditary Multiple Exostoses (HME) is a rare pediatric disorder caused by loss-of-function mutations in the genes encoding the heparan sulfate (HS)-synthesizing enzymes EXT1 or EXT2. HME is characterized by formation of cartilaginous outgrowths-called osteochondromas- next to the growth plates of many axial and appendicular skeletal elements. Surprisingly, it is not known whether such tumors also form in endochondral elements of the craniofacial skeleton. Here, we carried out a retrospective analysis of cervical spine MRI and CT scans from 50 consecutive HME patients that included cranial skeletal images. Interestingly, nearly half of the patients displayed moderate defects or osteochondroma-like outgrowths in the cranial base and specifically in the clivus. In good correlation, osteochondromas developed in the cranial base of mutant Ext1f/f;Col2-CreER or Ext1f/f;Aggrecan-CreER mouse models of HME along the synchondrosis growth plates. Osteochondroma formation was preceded by phenotypic alteration of cells at the chondro-perichondrial boundary and was accompanied by ectopic expression of major cartilage matrix genes -collagen 2 and collagen X- within the growing ectopic masses. Because chondrogenesis requires bone morphogenetic protein (BMP) signaling, we asked whether osteochondroma formation could be blocked by a BMP signaling antagonist. Systemic administration with LDN-193189 effectively inhibited osteochondroma growth in conditional Ext1-mutant mice. In vitro studies with mouse embryo chondrogenic cells clarified the mechanisms of LDN-193189 action that turned out to include decreases in canonical BMP signaling pSMAD1/5/8 effectors but interestingly, concurrent increases in such anti-chondrogenic mechanisms as pERK1/2 and Chordin, Fgf9 and Fgf18 expression. Our study is the first to reveal that the cranial base can be affected in patients with HME and that osteochondroma formation is amenable to therapeutic drug intervention.
Collapse
Affiliation(s)
- Sayantani Sinha
- Translational Research Program in Pediatric Orthopaedics, Division of Orthopaedic Surgery, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
| | - Christina Mundy
- Translational Research Program in Pediatric Orthopaedics, Division of Orthopaedic Surgery, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
| | - Till Bechtold
- Translational Research Program in Pediatric Orthopaedics, Division of Orthopaedic Surgery, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
| | - Federica Sgariglia
- Translational Research Program in Pediatric Orthopaedics, Division of Orthopaedic Surgery, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
| | - Mazen M. Ibrahim
- Translational Research Program in Pediatric Orthopaedics, Division of Orthopaedic Surgery, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
| | - Paul C. Billings
- Translational Research Program in Pediatric Orthopaedics, Division of Orthopaedic Surgery, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
| | - Kristen Carroll
- Shriner’s Hospital for Children, Salt Lake City, Utah, United States of America
- Department of Orthopaedics, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - Eiki Koyama
- Translational Research Program in Pediatric Orthopaedics, Division of Orthopaedic Surgery, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
| | - Kevin B. Jones
- Department of Orthopaedics, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
- Department of Oncological Sciences and Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
- * E-mail: (MP); (KBJ)
| | - Maurizio Pacifici
- Translational Research Program in Pediatric Orthopaedics, Division of Orthopaedic Surgery, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
- * E-mail: (MP); (KBJ)
| |
Collapse
|
13
|
Akbaroghli S, Balali M, Kamalidehghan B, Saber S, Aryani O, Meng GY, Houshmand M. Identification of a new mutation in an Iranian family with hereditary multiple osteochondromas. Ther Clin Risk Manag 2017; 13:15-19. [PMID: 28053536 PMCID: PMC5189706 DOI: 10.2147/tcrm.s111717] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Hereditary multiple osteochondromas (HMO), previously named hereditary multiple exostoses (HME), is an autosomal dominant skeletal disorder characterized by the growth of multiple osteochondromas and is associated with bony deformity, skeletal growth reduction, nerve compression, restriction of joint motion, and premature osteoarthrosis. HMO is genetically heterogeneous, localized on at least three chromosomal loci including 8q24.1 (EXT1), 11p11-p13 (EXT2), and 19p (EXT3). The median age of diagnosis is 3 years; almost all affected individuals are diagnosed by age 12. The risk for malignant degeneration to osteochondrosarcoma increases with age, although the lifetime risk of malignant degeneration is low (~1%). METHODS AND RESULTS This study was performed on an Iranian family with nine affected individuals from three consecutive generations. Here, the proband was an affected woman who received genetic counseling prior to pregnancy. All exons of the three genes were examined in the proband using polymerase chain reaction and sequencing methods (the last member of this family is a male with severe deformities and lesions, especially around his large joints). Exon 4 of EXT1 (c.1235 G>A) was changed in affected individuals. This mutation alters tryptophan to a premature stop codon on amino acid position 412 (p.Trp412x). CONCLUSION The outcome of this study has extended the genotypic spectrum of Iranian patients with HMO, revealing a way for improving detection and genetic counseling in carriers.
Collapse
Affiliation(s)
- Susan Akbaroghli
- Mofid Children's Hospital, Shahid Beheshti University of Medical Sciences
| | - Maryam Balali
- ENT and Head & Neck Research Center and Department, Iran University of Medical Sciences (IUMS)
| | - Behnam Kamalidehghan
- Medical Genetics Department, School of Medicine, Shahid Beheshti University of Medical Sciences; Medical Genetics Department, National Institute for Genetic Engineering and Biotechnology
| | - Siamak Saber
- Medical Genetics Department, National Institute for Genetic Engineering and Biotechnology
| | - Omid Aryani
- Department of Neuroscience, Iran Medical University, Tehran, Iran
| | - Goh Yong Meng
- Department of Veterinary Preclinical Sciences, Faculty of Veterinary Medicine, Universiti Putra Malaysia (UPM), Serdang, Malaysia
| | - Massoud Houshmand
- Medical Genetics Department, National Institute for Genetic Engineering and Biotechnology
| |
Collapse
|
14
|
Hong G, Guo X, Yan W, Li Q, Zhao H, Ma P, Hu X. Identification of a novel mutation in the EXT1 gene from a patient with multiple osteochondromas by exome sequencing. Mol Med Rep 2016; 15:657-664. [PMID: 28035357 PMCID: PMC5364847 DOI: 10.3892/mmr.2016.6086] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 11/18/2016] [Indexed: 01/16/2023] Open
Abstract
Multiple osteochondromas (MO) is an autosomal skeletal disease with an elusive molecular mechanism. To further elucidate the genetic mechanism of the disease a three-generation Chinese family with MO was observed and researched, and a novel frameshift mutation (c.335_336insA) in the exotosin 1 (EXT1) gene of one patient with MO was observed through exome sequencing. This was further validated by Sanger sequencing and comparison with 200 unrelated healthy controls. Immunohistochemistry and multiple sequence alignment were performed to determine the pathogenicity of the candidate mutation. Multiple sequence alignment suggested that codon 335 and 336 in the EXT1 gene were highly conserved regions in vertebrates. Immunohistochemistry revealed that EXT1 protein expression levels were decreased in a patient with MO and this mutation compared with a patient with MO who had no EXT1 mutation. Owing to the appearance of c.335_336insA in exon 1 of EXT1, a premature stop codon was introduced, resulting in truncated EXT1. As a result integrated and functional EXT1 was reduced. EXT1 is involved in the biosynthesis of heparan sulfate (HS), an essential molecule, and its dysfunction may lead to MO. The novel mutation of c.335_336insA in the EXT1 gene reported in the present study has enlarged the causal mutation spectrum of MO, and may assist genetic counseling and prenatal diagnosis of MO.
Collapse
Affiliation(s)
- Guolin Hong
- Department of Laboratory Medicine, The First Affiliated Hospital of Xiamen University, Xiamen, Fujian 361003, P.R. China
| | - Xiaoyan Guo
- Department of Laboratory Medicine, The Fuzhou Second Affiliated Hospital of Xiamen University, Fuzhou, Fujian 350007, P.R. China
| | - Wei Yan
- Department of Bone Tumors, The Fuzhou Second Affiliated Hospital of Xiamen University, Fuzhou, Fujian 350007, P.R. China
| | - Qianqian Li
- Medical College, Xiamen University, Xiamen, Fujian 361102, P.R. China
| | - Hailing Zhao
- Medical College, Xiamen University, Xiamen, Fujian 361102, P.R. China
| | - Ping Ma
- Medical College, Xiamen University, Xiamen, Fujian 361102, P.R. China
| | - Xiao Hu
- Shenzhen Huada Gene Research Institute, Shenzhen, Fujian 518083, P.R. China
| |
Collapse
|
15
|
Heparanase: a rainbow pharmacological target associated to multiple pathologies including rare diseases. Future Med Chem 2016; 8:647-80. [PMID: 27057774 DOI: 10.4155/fmc-2016-0012] [Citation(s) in RCA: 135] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
In recent years, heparanase has attracted considerable attention as a promising target for innovative pharmacological applications. Heparanase is a multifaceted protein endowed with enzymatic activity, as an endo-β-D-glucuronidase, and nonenzymatic functions. It is responsible for the cleavage of heparan sulfate side chains of proteoglycans, resulting in structural alterations of the extracellular matrix. Heparanase appears to be involved in major human diseases, from the most studied tumors to chronic inflammation, diabetic nephropathy, bone osteolysis, thrombosis and atherosclerosis, in addition to more recent investigation in various rare diseases. The present review provides an overview on heparanase, its biological role, inhibitors and possible clinical applications, covering the latest findings in these areas.
Collapse
|
16
|
Tosi LL, Warman ML. Mechanistic and therapeutic insights gained from studying rare skeletal diseases. Bone 2015; 76:67-75. [PMID: 25819040 DOI: 10.1016/j.bone.2015.03.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2015] [Accepted: 03/19/2015] [Indexed: 12/14/2022]
Abstract
Rare bone diseases account for 5% of all birth defects and can cause significant morbidity throughout patients' lives. Significant progress is being made to elucidate the pathophysiological mechanisms underlying these diseases. This paper summarizes presentation highlights of a workshop on Rare Skeletal Diseases convened to explore how the study of rare diseases has influenced the field's understanding of bone anabolism and catabolism and directed the search for new therapies benefiting patients with rare conditions as well as patients with common skeletal disorders.
Collapse
Affiliation(s)
- Laura L Tosi
- Division of Orthopaedics and Sports Medicine, Children's National Health System, 111 Michigan Avenue NW, Washington, DC 20010, USA.
| | - Matthew L Warman
- Orthopaedic Research Laboratories, Boston Children's Hospital, 320 Longwood Avenue, Room EN260.1, Boston, MA 02115, USA.
| |
Collapse
|
17
|
Huegel J, Enomoto-Iwamoto M, Sgariglia F, Koyama E, Pacifici M. Heparanase stimulates chondrogenesis and is up-regulated in human ectopic cartilage: a mechanism possibly involved in hereditary multiple exostoses. THE AMERICAN JOURNAL OF PATHOLOGY 2015; 185:1676-85. [PMID: 25863260 PMCID: PMC4450318 DOI: 10.1016/j.ajpath.2015.02.014] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Revised: 01/21/2015] [Accepted: 02/10/2015] [Indexed: 01/10/2023]
Abstract
Hereditary multiple exostoses is a pediatric skeletal disorder characterized by benign cartilaginous tumors called exostoses that form next to growing skeletal elements. Hereditary multiple exostoses patients carry heterozygous mutations in the heparan sulfate (HS)-synthesizing enzymes EXT1 or EXT2, but studies suggest that EXT haploinsufficiency and ensuing partial HS deficiency are insufficient for exostosis formation. Searching for additional pathways, we analyzed presence and distribution of heparanase in human exostoses. Heparanase was readily detectable in most chondrocytes, particularly in cell clusters. In control growth plates from unaffected persons, however, heparanase was detectable only in hypertrophic zone. Treatment of mouse embryo limb mesenchymal micromass cultures with exogenous heparanase greatly stimulated chondrogenesis and bone morphogenetic protein signaling as revealed by Smad1/5/8 phosphorylation. It also stimulated cell migration and proliferation. Interfering with HS function both with the chemical antagonist Surfen or treatment with bacterial heparitinase up-regulated endogenous heparanase gene expression, suggesting a counterintuitive feedback mechanism that would result in further HS reduction and increased signaling. Thus, we tested a potent heparanase inhibitor (SST0001), which strongly inhibited chondrogenesis. Our data clearly indicate that heparanase is able to stimulate chondrogenesis, bone morphogenetic protein signaling, cell migration, and cell proliferation in chondrogenic cells. These properties may allow heparanase to play a role in exostosis genesis and pathogenesis, thus making it a conceivable therapeutic target in hereditary multiple exostoses.
Collapse
Affiliation(s)
- Julianne Huegel
- Translational Research Program in Pediatric Orthopaedics, Division of Orthopaedic Surgery, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Motomi Enomoto-Iwamoto
- Translational Research Program in Pediatric Orthopaedics, Division of Orthopaedic Surgery, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Federica Sgariglia
- Translational Research Program in Pediatric Orthopaedics, Division of Orthopaedic Surgery, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Eiki Koyama
- Translational Research Program in Pediatric Orthopaedics, Division of Orthopaedic Surgery, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Maurizio Pacifici
- Translational Research Program in Pediatric Orthopaedics, Division of Orthopaedic Surgery, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania.
| |
Collapse
|
18
|
Aerts BRJ, van Heeswijk EJM, Beumer A. Reconstruction of the DRUJ in a young adult after resection of a large exostosis of the distal radius. Strategies Trauma Limb Reconstr 2015; 10:123-7. [PMID: 25877933 PMCID: PMC4570885 DOI: 10.1007/s11751-015-0224-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2014] [Accepted: 04/03/2015] [Indexed: 11/30/2022] Open
Abstract
The prevalence of known solitary exostosis is around 1–2 % in the general population. Treatment of an exostosis may consist of resection with or without further treatment for deformity. The distal radioulnar joint (DRUJ) acts as the link between radius and ulna at the wrist and is important in the transmission of load. Its anatomic integrity should be respected in surgical procedures or ulnar-sided wrist pain because of instability, limitation of forearm rotation and potential development of grip weakness may develop. We present a case of reconstruction of the DRUJ with distraction lengthening of the ulna after resection of a large exostosis of the distal radius that had resulted in a malformed and dysplastic ulna. This treatment in a young patient resulted in a stable, functional and congruent distal radioulnar joint.
Collapse
Affiliation(s)
- Bas R J Aerts
- Department of Orthopaedic Surgery, Upper Limb Unit, Amphia Hospital, Molengracht 21, 4818 CK, Breda, The Netherlands.
| | - E J M van Heeswijk
- Department of Orthopaedic Surgery, Upper Limb Unit, Amphia Hospital, Molengracht 21, 4818 CK, Breda, The Netherlands
| | - Annechien Beumer
- Department of Orthopaedic Surgery, Upper Limb Unit, Amphia Hospital, Molengracht 21, 4818 CK, Breda, The Netherlands
| |
Collapse
|
19
|
Jones KB, Pacifici M, Hilton MJ. Multiple hereditary exostoses (MHE): elucidating the pathogenesis of a rare skeletal disorder through interdisciplinary research. Connect Tissue Res 2014; 55:80-8. [PMID: 24409815 DOI: 10.3109/03008207.2013.867957] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Abstract An interdisciplinary and international group of clinicians and scientists gathered in Philadelphia, PA, to attend the fourth International Research Conference on Multiple Hereditary Exostoses (MHE), a rare and severe skeletal disorder. MHE is largely caused by autosomal dominant mutations in EXT1 or EXT2, genes encoding Golgi-associated glycosyltransferases responsible for heparan sulfate (HS) synthesis. HS chains are key constituents of cell surface- and extracellular matrix-associated proteoglycans, which are known regulators of skeletal development. MHE affected individuals are HS-deficient, can display skeletal growth retardation and deformities, and consistently develop benign, cartilage-capped bony outgrowths (termed exostoses or osteochondromas) near the growth plates of many skeletal elements. Nearly 2% of patients will have their exostoses progress to malignancy, becoming peripheral chondrosarcomas. Current treatments are limited to the surgical removal of symptomatic exostoses. No definitive treatments have been established to inhibit further formation and growth of exostoses, prevent transition to malignancy, or address other medical problems experienced by MHE patients, including chronic pain. Thus, the goals of the Conference were to assess our current understanding of MHE pathogenesis, identify key gaps in information, envision future therapeutic strategies and discuss ways to test and implement them. This report provides an assessment of the exciting and promising findings in MHE and related fields presented at the Conference and a discussion of the future MHE research directions. The Conference underlined the critical usefulness of gathering experts in several research fields to forge new alliances and identify cross-fertilization areas to benefit both basic and translational biomedical research on the skeleton.
Collapse
Affiliation(s)
- Kevin B Jones
- Department of Orthopaedics and Center for Children's Cancer Research, Huntsman Cancer Institute, University of Utah School of Medicine , Salt Lake City, UT , USA
| | | | | |
Collapse
|
20
|
Guo XL, Deng Y, Liu HG. Clinical characteristics of hereditary multiple exostoses: a retrospective study of mainland chinese cases in recent 23 years. ACTA ACUST UNITED AC 2014; 34:42-50. [PMID: 24496678 DOI: 10.1007/s11596-014-1230-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Revised: 10/25/2013] [Indexed: 11/25/2022]
Abstract
Hereditary multiple exostoses (HME) are an autosomal dominant skeletal disease with wide variations in clinical manifestations among different ethnic groups. This study investigated the epidemiology, clinical presentations, pathogenetic features and treatment strategies of HME in mainland China. We searched and reviewed the related cases published since 1990 by searching electronic databases, namely SinoMed database, Wanfang database, CNKI, Web of Science and PubMed as well as Google search engines. A total of 1051 cases of HME (male-to-female ratio 1.5:1) were investigated and the diagnosis was made in 83% before the age of 10 years. Approximately 96% patients had a family history. Long bones, ribs, scapula and pelvis were the frequently affected sites. Most patients were asymptomatic with multiple palpable masses. Common complications included angular deformities, impingement on neighbouring tissues and impaired articular function. Chondrosarcomas transformation occurred in 2% Chinese cases. Among the cases examined, about 18% had mutations in EXT1 and 28% in EXT2. Frameshift, nonsense and missense mutations represented the majority of HME-causing mutations. Diagnosis of HME was made based on the clinical presentations and radiological documentations. Most patients needed no treatment. Surgical treatment was often directed to remove symptomatic exostoses, particularly those of suspected malignancy degeneration, and correction of skeletal deformities. This study shows some variance from current literature regarding other ethnic populations and may provide valuable baseline assessment of the natural history of HME in mainland China.
Collapse
Affiliation(s)
- Xue-Ling Guo
- Department of Respiratory and Critical Care Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Key Laboratory of Respiratory Disease of the Ministry of Health, Wuhan, 430030, China
| | - Yan Deng
- Department of Respiratory and Critical Care Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Key Laboratory of Respiratory Disease of the Ministry of Health, Wuhan, 430030, China
| | - Hui-Guo Liu
- Department of Respiratory and Critical Care Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Key Laboratory of Respiratory Disease of the Ministry of Health, Wuhan, 430030, China.
| |
Collapse
|
21
|
Sgariglia F, Candela ME, Huegel J, Jacenko O, Koyama E, Yamaguchi Y, Pacifici M, Enomoto-Iwamoto M. Epiphyseal abnormalities, trabecular bone loss and articular chondrocyte hypertrophy develop in the long bones of postnatal Ext1-deficient mice. Bone 2013; 57:220-31. [PMID: 23958822 PMCID: PMC4107462 DOI: 10.1016/j.bone.2013.08.012] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Revised: 08/05/2013] [Accepted: 08/13/2013] [Indexed: 11/25/2022]
Abstract
Long bones are integral components of the limb skeleton. Recent studies have indicated that embryonic long bone development is altered by mutations in Ext genes and consequent heparan sulfate (HS) deficiency, possibly due to changes in activity and distribution of HS-binding/growth plate-associated signaling proteins. Here we asked whether Ext function is continuously required after birth to sustain growth plate function and long bone growth and organization. Compound transgenic Ext1(f/f);Col2CreERT mice were injected with tamoxifen at postnatal day 5 (P5) to ablate Ext1 in cartilage and monitored over time. The Ext1-deficient mice exhibited growth retardation already by 2weeks post-injection, as did their long bones. Mutant growth plates displayed a severe disorganization of chondrocyte columnar organization, a shortened hypertrophic zone with low expression of collagen X and MMP-13, and reduced primary spongiosa accompanied, however, by increased numbers of TRAP-positive osteoclasts at the chondro-osseous border. The mutant epiphyses were abnormal as well. Formation of a secondary ossification center was significantly delayed but interestingly, hypertrophic-like chondrocytes emerged within articular cartilage, similar to those often seen in osteoarthritic joints. Indeed, the cells displayed a large size and round shape, expressed collagen X and MMP-13 and were surrounded by an abundant Perlecan-rich pericellular matrix not seen in control articular chondrocytes. In addition, ectopic cartilaginous outgrowths developed on the lateral side of mutant growth plates over time that resembled exostotic characteristic of children with Hereditary Multiple Exostoses, a syndrome caused by Ext mutations and HS deficiency. In sum, the data do show that Ext1 is continuously required for postnatal growth and organization of long bones as well as their adjacent joints. Ext1 deficiency elicits defects that can occur in human skeletal conditions including trabecular bone loss, osteoarthritis and HME.
Collapse
Affiliation(s)
- Federica Sgariglia
- Translational Research Program in Pediatric Orthopaedics, Division of Orthopaedic Surgery, Department of Surgery, The Children's Hospital of Philadelphia, Philadelphia, PA 19104
| | - Maria Elena Candela
- Translational Research Program in Pediatric Orthopaedics, Division of Orthopaedic Surgery, Department of Surgery, The Children's Hospital of Philadelphia, Philadelphia, PA 19104
| | - Julianne Huegel
- Translational Research Program in Pediatric Orthopaedics, Division of Orthopaedic Surgery, Department of Surgery, The Children's Hospital of Philadelphia, Philadelphia, PA 19104
| | - Olena Jacenko
- Department of Animal Biology, School of Veterinary Medicine, University of Philadelphia, Philadelphia, PA 19104
| | - Eiki Koyama
- Translational Research Program in Pediatric Orthopaedics, Division of Orthopaedic Surgery, Department of Surgery, The Children's Hospital of Philadelphia, Philadelphia, PA 19104
- Department of Orthopaedic Surgery, Perelman School of Medicine, University of Philadelphia, Philadelphia, PA 19104
| | - Yu Yamaguchi
- Sanford Children's Health Research Center, Sanford-Burnham Medical Research Institute, La Jolla, CA, 92037
| | - Maurizio Pacifici
- Translational Research Program in Pediatric Orthopaedics, Division of Orthopaedic Surgery, Department of Surgery, The Children's Hospital of Philadelphia, Philadelphia, PA 19104
- Department of Orthopaedic Surgery, Perelman School of Medicine, University of Philadelphia, Philadelphia, PA 19104
| | - Motomi Enomoto-Iwamoto
- Translational Research Program in Pediatric Orthopaedics, Division of Orthopaedic Surgery, Department of Surgery, The Children's Hospital of Philadelphia, Philadelphia, PA 19104
- Department of Orthopaedic Surgery, Perelman School of Medicine, University of Philadelphia, Philadelphia, PA 19104
| |
Collapse
|
22
|
Huegel J, Sgariglia F, Enomoto-Iwamoto M, Koyama E, Dormans JP, Pacifici M. Heparan sulfate in skeletal development, growth, and pathology: the case of hereditary multiple exostoses. Dev Dyn 2013; 242:1021-32. [PMID: 23821404 DOI: 10.1002/dvdy.24010] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Revised: 06/21/2013] [Accepted: 06/22/2013] [Indexed: 12/14/2022] Open
Abstract
Heparan sulfate (HS) is an essential component of cell surface and matrix-associated proteoglycans. Due to their sulfation patterns, the HS chains interact with numerous signaling proteins and regulate their distribution and activity on target cells. Many of these proteins, including bone morphogenetic protein family members, are expressed in the growth plate of developing skeletal elements, and several skeletal phenotypes are caused by mutations in those proteins as well as in HS-synthesizing and modifying enzymes. The disease we discuss here is hereditary multiple exostoses (HME), a disorder caused by mutations in HS synthesizing enzymes EXT1 and EXT2, leading to HS deficiency. The exostoses are benign cartilaginous-bony outgrowths, form next to growth plates, can cause growth retardation and deformities, chronic pain and impaired motion, and progress to malignancy in 2-5% of patients. We describe recent advancements on HME pathogenesis and exostosis formation deriving from studies that have determined distribution, activities and roles of signaling proteins in wild-type and HS-deficient cells and tissues. Aberrant distribution of signaling factors combined with aberrant responsiveness of target cells to those same factors appear to be a major culprit in exostosis formation. Insights from these studies suggest plausible and cogent ideas about how HME could be treated in the future.
Collapse
Affiliation(s)
- Julianne Huegel
- Translational Research Program in Pediatric Orthopaedics, Division of Orthopaedic Surgery, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA.
| | | | | | | | | | | |
Collapse
|
23
|
Cell biology of osteochondromas: bone morphogenic protein signalling and heparan sulphates. INTERNATIONAL ORTHOPAEDICS 2013; 37:1591-6. [PMID: 23771188 DOI: 10.1007/s00264-013-1906-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Accepted: 04/18/2013] [Indexed: 01/01/2023]
Abstract
Frequent benign outgrowths from bone known as osteochondromas, exhibiting typical endochondral ossification, are reported from single to multiple lesions. Characterised by a high incidence of osteochondromas and skeletal deformities, multiple hereditary exostoses (MHE) is the most common inherited musculoskeletal condition. While factors for severity remain unknown, mutations in exostosin 1 and exostosin 2 genes, encoding glycosyltransferases involved in the biosynthesis of ubiquitously expressed heparan sulphate (HS) chains, are associated with MHE. HS-binding bone morphogenetic proteins (BMPs) are multifunctional proteins involved in the morphogenesis of bone and cartilage. HS and HS proteoglycans are involved in BMP-mediated morphogenesis by regulating their gradient formation and activity. Mutations in exostosin genes disturb HS biosynthesis, subsequently affecting its functional role in the regulation of signalling pathways. As BMPs are the primordial morphogens for bone development, we propose the hypothesis that BMP signalling may be critical in osteochondromas. For this reason, the outcomes of exostosin mutations on HS biosynthesis and interactions within osteochondromas and MHE are reviewed. Since BMPs are HS binding proteins, the interactions of HS with the BMP signalling pathway are discussed. The impact of mouse models in the quest to better understand the cell biology of osteochondromas is discussed. Several challenges and questions still remain and further investigations are needed to explore new approaches for better understanding of the pathogenesis of osteochondromas.
Collapse
|
24
|
Spinal stenosis frequent in children with multiple hereditary exostoses. J Child Orthop 2013; 7:183-94. [PMID: 24432077 PMCID: PMC3672460 DOI: 10.1007/s11832-013-0484-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Accepted: 01/28/2013] [Indexed: 02/03/2023] Open
Abstract
PURPOSE Children with multiple hereditary exostoses (MHE) have numerous osteochondromas, with the most prominent lesions typically over the appendicular skeleton. A recent report noted a high rate of intracanal lesions in this patient population and recommended preventative spinal screening with magnetic resonance imaging (MRI) or computed tomography (CT). We sought to evaluate the prevalence of spinal stenosis from intracanal osteochondromas at our pediatric orthopedic center in order to evaluate if routine screening is warranted. METHODS All pediatric patients treated for MHE were retrospectively identified. Records were reviewed to determine demographics, previous orthopedic surgery, and indication and results of axial spine imaging (CT or MRI). Imaging studies were reviewed to evaluate the presence of intracanal and compressive spinal lesions. RESULTS Between 1990 and 2011, axial imaging was performed in nine patients with MHE due to concerns of pain, weakness, and/or dizziness. These patients had moderate disease involvement, with a mean of 4.9 previous orthopedic surgeries to address skeletal osteochondromas. Two patients with MHE had cervical spinal stenosis secondary to intracanal osteochondromas. Both children successfully underwent spinal decompression. Thus, of our MHE population undergoing axial imaging, 22 % were noted to have intracanal lesions. CONCLUSIONS Our experience reveals a >20 % rate of compressive intracanal osteochondromas in MHE patients undergoing spinal imaging. These two patients represent 5 % of the MHE patients treated at our center. These lesions may be slow growing, and significant consequences can occur if not identified promptly. Thus, we confer that routine axial screening of the spinal canal may be warranted in these children.
Collapse
|
25
|
Weinstein T, Evron Z, Trebicz-Geffen M, Aviv M, Robinson D, Kollander Y, Nevo Z. β-D-xylosides stimulate GAG synthesis in chondrocyte cultures due to elevation of the extracellular GAG domains, accompanied by the depletion of the intra-pericellular GAG pools, with alterations in the GAG profiles. Connect Tissue Res 2011; 53:169-79. [PMID: 22149722 DOI: 10.3109/03008207.2011.620190] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The familial disease of hereditary multiple exostoses is characterized by abnormal skeletal deformities requiring extensive surgical procedures. In hereditary multiple exostoses patients there is a shortage in the pericellular glycosaminoglycan (GAG) of heparan sulfate (HS), related to defective activity of HS glycosyltransferases, mainly in the pericellular regions of chondrocytes. This study searched for a novel approach employing xylosides with different aglycone groups priming a variety of GAG chains, in attempting to alter the GAG compositional profile. Cell cultures of patients with osteochondroma responded to p-nitrophenyl β-D-xyloside by a significant increase in total GAG synthesis, expressed mainly in the extracellular domains, limited to chondroitin sulfate). The different β-D-xylosides, in addition to increasing the synthesis of extracellular GAGs, led to a significant depletion of the intracellular GAG domains. In mouse chondrocyte cultures, β-D-xylosides with different aglycones created a unique distribution of the GAG pools. Of special interest was the finding that the naphthalene methanol β-D-xyloside showed the highest absolute levels of HS-GAGs in both extracellular and intra-pericellular moieties compared with other β-D-xylosides and with controls without xyloside. In summary, β-D-xylosides can be utilized in chondrocyte cultures to modify the distribution of GAGs between the extracellular and intracellular compartments. In addition, xylosides may alter the profile of specific GAG chains in each moiety.
Collapse
Affiliation(s)
- Talia Weinstein
- Department of Nephrology, Tel Aviv Sourasky Medical Center, Sackler School of Medicine, Tel Aviv University, Ramat Aviv, Tel Aviv, Israel
| | | | | | | | | | | | | |
Collapse
|
26
|
Burki V, So A, Aubry-Rozier B. Cervical myelopathy in hereditary multiple exostoses. Joint Bone Spine 2011; 78:412-4. [DOI: 10.1016/j.jbspin.2011.02.021] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2010] [Accepted: 02/24/2011] [Indexed: 10/18/2022]
|
27
|
Bickels J, Weinstein T, Robinson D, Nevo Z. Common skeletal growth retardation disorders resulting from abnormalities within the mesenchymal stem cells reservoirs in the epiphyseal organs pertaining to the long bones. J Pediatr Endocrinol Metab 2010; 23:1107-22. [PMID: 21284324 DOI: 10.1515/jpem.2010.176] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Among the objectives in writing the current chapter were the curiosity and the interest in allocating the sites and routes of migration of the reservoirs of the mesenchymal precartilaginous stem cells of the developing limbs in health and in disease. We chose to emphasize the events believed to initiate in these regions of stem cells, which may lead to growth retardation disorders. Thus, this narrow niche touches an enlarged scope of developmental biology angles and fields. The enclosed coverage sheds light on part of the musculoskeletal system, skeletogenesis, organogenesis of mobile structures and organs, the limbs, joints and digits (arthrology). It appears that the key role of the cartilage-bone regions is their responsibility to replenish the physis with committed chondrocytes, during the developmental, maturation and puberty periods. We shall start by outlining the framework of normal limb formation, the modalities, signals and the agents participating in this biological creation and regulation, illustrating potential sites that might deviate from normal development during the growth periods.
Collapse
Affiliation(s)
- Jacob Bickels
- Dept. of Orthopedic-Oncology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | | | | | | |
Collapse
|
28
|
Ezra N, Tetteh B, Diament M, Jonas AJ, Dickson P. Hereditary multiple exostoses with spine involvement in a 4-year-old boy. Am J Med Genet A 2010; 152A:1264-7. [DOI: 10.1002/ajmg.a.33345] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
29
|
Genetic models of osteochondroma onset and neoplastic progression: evidence for mechanisms alternative to EXT genes inactivation. Oncogene 2010; 29:3827-34. [DOI: 10.1038/onc.2010.135] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
30
|
Li Y, Wang J, Li H, Wang J, Wang X, Fu Q. A novel EXT1 gene mutation causing hereditary multiple exostoses in a Chinese pedigree. Pathology 2009; 42:91-3. [PMID: 20025490 DOI: 10.3109/00313020903434694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
31
|
Li Y, Wang D, Wang W, Wang J, Li H, Wang J, Wang X, Fu Q. Identification of four novel EXT1 and EXT2 mutations in five Chinese pedigrees with hereditary multiple exostoses. Genet Test Mol Biomarkers 2009; 13:825-30. [PMID: 19839753 DOI: 10.1089/gtmb.2009.0083] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Hereditary multiple exostoses (HME) is an autosomal dominant skeletal disorder most frequently caused by the EXT1 and EXT2 gene mutations resulting in reduction or absence of heparan sulfate (HS) in the exostotic cartilage cap. In this study, we investigated the molecular defects in five Chinese pedigrees with HME by direct sequencing analysis. Two novel EXT1 gene mutations and two novel EXT2 gene mutations were identified in two and three pedigrees, respectively. Of the four mutations identified, the c.651-664delinsTTT and c.680delG mutations in the exon 1 of EXT1 gene would cause frameshift (K218fs and R227fs) and introduce premature stop codon at amino acid site 220 and 251, respectively. The two missense mutations of c.398T > G in exon 2 and c.1016G > A in exon 6 of EXT2 gene result in the Leu133Arg and Cys339Tyr substitution, respectively. As HME is caused by defects in HS synthesis that is a complex process and not fully understood, these naturally occurring EXT mutations may provide important clues to future studies elucidating how EXT proteins contribute to HS biosynthesis.
Collapse
Affiliation(s)
- Yuchan Li
- Department of Pediatric Orthopedics, Shanghai Children's Medical Center, Shanghai Jiaotong University School of Medicine, Shanghai, People's Republic of China
| | | | | | | | | | | | | | | |
Collapse
|
32
|
Reijnders CMA, Hogendoorn PCW, Bovée JVMG. The molecular and cellular basis of exostosis formation in hereditary multiple exostoses. Int J Exp Pathol 2009; 90:190-1; author reply 191-3. [DOI: 10.1111/j.1365-2613.2009.00654.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
|