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Maurizi A. Experimental therapies for osteopetrosis. Bone 2022; 165:116567. [PMID: 36152941 DOI: 10.1016/j.bone.2022.116567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Revised: 09/13/2022] [Accepted: 09/20/2022] [Indexed: 11/17/2022]
Abstract
The medical treatment of osteopetrosis is an ongoing clinical problem. There are no effective and safer therapeutic approaches for all its forms. However, recent discoveries concerning the etiology and the pathogenesis of osteopetrosis, the development of dedicated cellular and animal models, and the advent of new technologies are paving the way for the development of targeted and safer therapies for both lethal and milder osteopetrosis. This review summarizes the huge effort and successes made by researchers to identify and develop new experimental approaches with this objective, such as the use of non-genotoxic myeloablation, gene correction of inducible Pluripotent Stem Cells (iPSCs), lentiviral-based gene therapy, protein replacement, prenatal treatment, osteoclast precursors transplantation and RNA Interference.
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Affiliation(s)
- Antonio Maurizi
- Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, 67100 L'Aquila, Italy.
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Capo V, Abinun M, Villa A. Osteoclast rich osteopetrosis due to defects in the TCIRG1 gene. Bone 2022; 165:116519. [PMID: 35981697 DOI: 10.1016/j.bone.2022.116519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 08/10/2022] [Accepted: 08/11/2022] [Indexed: 11/28/2022]
Abstract
Discovery that mutations in TCIRG1 (also known as Atp6i) gene are responsible for most instances of autosomal recessive osteopetrosis (ARO) heralded a new era for comprehension and treatment of this phenotypically heterogeneous rare bone disease. TCIRG1 encodes the a3 subunit, an essential isoform of the vacuolar ATPase proton pump involved in acidification of the osteoclast resorption lacuna and in secretory lysosome trafficking. TCIRG1 defects lead to inefficient bone resorption by nonfunctional osteoclasts seen in abundance on bone marrow biopsy, delineating this ARO as 'osteoclast-rich'. Presentation is usually in early childhood and features of extramedullary haematopoiesis (hepatosplenomegaly, anaemia, thrombocytopenia) due to bone marrow fibrosis, and cranial nerve impingement (blindness in particular). Impaired dietary calcium uptake due to high pH causes the co-occurrence of rickets, described as "osteopetrorickets". Osteoclast dysfunction leads to early death if untreated, and allogeneic haematopoietic stem cell transplantation is currently the treatment of choice. Studies of patients as well as of mouse models carrying spontaneous (the oc/oc mouse) or targeted disruption of Atp6i (TCIRG1) gene have been instrumental providing insight into disease pathogenesis and development of novel cellular therapies that exploit gene correction.
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Affiliation(s)
- Valentina Capo
- San Raffaele Telethon Institute for Gene Therapy (SR-Tiget), IRCCS San Raffaele Scientific Institute, Milan, Italy; Institute of Genetic and Biomedical Research, Milan Unit, National Research Council, Milan, Italy
| | - Mario Abinun
- Children's Haematopoietic Stem Cell Transplantation Unit, Great North Children's Hospital, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK; Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Anna Villa
- San Raffaele Telethon Institute for Gene Therapy (SR-Tiget), IRCCS San Raffaele Scientific Institute, Milan, Italy; Institute of Genetic and Biomedical Research, Milan Unit, National Research Council, Milan, Italy.
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Penna S, Villa A, Capo V. Autosomal recessive osteopetrosis: mechanisms and treatments. Dis Model Mech 2021; 14:261835. [PMID: 33970241 PMCID: PMC8188884 DOI: 10.1242/dmm.048940] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Autosomal recessive osteopetrosis (ARO) is a severe inherited bone disease characterized by defective osteoclast resorption or differentiation. Clinical manifestations include dense and brittle bones, anemia and progressive nerve compression, which hamper the quality of patients' lives and cause death in the first 10 years of age. This Review describes the pathogenesis of ARO and highlights the strengths and weaknesses of the current standard of care, namely hematopoietic stem cell transplantation (HSCT). Despite an improvement in the overall survival and outcomes of HSCT, transplant-related morbidity and the pre-existence of neurological symptoms significantly limit the success of HSCT, while the availability of human leukocyte antigen (HLA)-matched donors still remains an open issue. Novel therapeutic approaches are needed for ARO patients, especially for those that cannot benefit from HSCT. Here, we review preclinical and proof-of-concept studies, such as gene therapy, systematic administration of deficient protein, in utero HSCT and gene editing. Summary: Autosomal recessive osteopetrosis is a heterogeneous and rare bone disease for which effective treatments are still lacking for many patients. Here, we review the literature on clinical, preclinical and proof-of-concept studies.
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Affiliation(s)
- Sara Penna
- San Raffaele Telethon Institute for Gene Therapy (SR-Tiget), IRCCS San Raffaele Scientific Institute, Milan 20132, Italy.,Translational and Molecular Medicine (DIMET), University of Milano-Bicocca, Monza 20900, Italy
| | - Anna Villa
- San Raffaele Telethon Institute for Gene Therapy (SR-Tiget), IRCCS San Raffaele Scientific Institute, Milan 20132, Italy.,Institute of Genetic and Biomedical Research, Milan Unit, National Research Council, Milan 20090, Italy
| | - Valentina Capo
- San Raffaele Telethon Institute for Gene Therapy (SR-Tiget), IRCCS San Raffaele Scientific Institute, Milan 20132, Italy.,Institute of Genetic and Biomedical Research, Milan Unit, National Research Council, Milan 20090, Italy
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Wang Y, Wu C, Tao J, Zhao D, Jiang X, Tian W. Differential proteomic analysis of tibial subchondral bone from male and female guinea pigs with spontaneous osteoarthritis. Exp Ther Med 2021; 21:633. [PMID: 33968164 PMCID: PMC8097192 DOI: 10.3892/etm.2021.10065] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 03/17/2021] [Indexed: 12/20/2022] Open
Abstract
A proteomic study on the tibial subchondral bone in guinea pigs with spontaneous osteoarthritis was performed to investigate the molecular alterations that occur in early osteoarthritis. A total of 132 healthy Hartley guinea pigs (aged 1 month; 66 female and 66 male) were randomly divided into 11 groups of six. Changes in articular cartilage and tibial subchondral bone were assessed using macroscopic examinations and micro-computed tomography. iTRAQ-integrated liquid chromatography-tandem mass spectrometry was used to identify differentially altered proteins in the tibial subchondral bone between 1- and 3-month-old guinea pigs, which were then validated using western blotting. A gradual progression of cartilage degeneration was observed in the knee joints of the subject animals from 5-11 months. With aging, the tibial subchondral trabecular bone acquired more plate-like and less anisotropic properties, with increased bone mineral density, bone volume, trabecular thickness and numbers. The proteomic study identified 138 and 113 proteins significantly differentially expressed between 3- and 1-month old guinea pigs in both the male and female animals, respectively. Western blotting confirmed the increased expression of osteoblast-associated protein S100 calcium-binding protein A8 (S100A8) and the deregulated expression of osteoclast-associated proteins coronin 1A (CORO1A) and T-cell immune regulator 1 (TCIRG1) in the 3-month old guinea pigs in comparison to the 1-month old guinea pigs. Spontaneous cartilage degeneration in the knee joints of male Hartley guinea pigs tended to be more serious compared with the females during the development of osteoarthritis. Together, the results suggest that osteoblast-associated protein S100A8 and osteoclast-associated proteins CORO1A and TCIRG1 are potentially key regulators of early osteoarthritic development in tibial subchondral bone.
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Affiliation(s)
- Ying Wang
- Department of Molecular Orthopedics, Beijing Research Institute of Traumatology and Orthopedics, Beijing 100035, P.R. China
| | - Chengai Wu
- Department of Molecular Orthopedics, Beijing Research Institute of Traumatology and Orthopedics, Beijing 100035, P.R. China
| | - Jianfeng Tao
- Department of Molecular Orthopedics, Beijing Research Institute of Traumatology and Orthopedics, Beijing 100035, P.R. China
| | - Danhui Zhao
- Animal Laboratory, Beijing Research Institute of Traumatology and Orthopedics, Beijing 100035, P.R. China
| | - Xu Jiang
- Department of Orthopedics, Beijing Jishuitan Hospital, Beijing 100035, P.R. China
| | - Wei Tian
- Department of Spine Surgery, Beijing Jishuitan Hospital, Beijing 100035, P.R. China
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Moscatelli I, Almarza E, Schambach A, Ricks D, Schulz A, Herzog CD, Henriksen K, Askmyr M, Schwartz JD, Richter J. Gene therapy for infantile malignant osteopetrosis: review of pre-clinical research and proof-of-concept for phenotypic reversal. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2021; 20:389-397. [PMID: 33575431 PMCID: PMC7848732 DOI: 10.1016/j.omtm.2020.12.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Infantile malignant osteopetrosis is a devastating disorder of early childhood that is frequently fatal and for which there are only limited therapeutic options. Gene therapy utilizing autologous hematopoietic stem and progenitor cells represents a potentially advantageous therapeutic alternative for this multisystemic disease. Gene therapy can be performed relatively rapidly following diagnosis, will not result in graft versus host disease, and may also have potential for reduced incidences of other transplant-related complications. In this review, we have summarized the past sixteen years of research aimed at developing a gene therapy for infantile malignant osteopetrosis; these efforts have culminated in the first clinical trial employing lentiviral-mediated delivery of TCIRG1 in autologous hematopoietic stem and progenitor cells.
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Affiliation(s)
- Ilana Moscatelli
- Department of Molecular Medicine and Gene Therapy, Lund Strategic Center for Stem Cell Biology, Lund University, Lund, Sweden
| | | | - Axel Schambach
- Institute of Experimental Hematology, Hannover Medical School, Hannover, Germany.,Division of Hematology/Oncology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - David Ricks
- Rocket Pharmaceuticals, Inc., New York, NY, USA
| | - Ansgar Schulz
- Department of Pediatrics and Adolescent Medicine, University Medical Center Ulm, Germany
| | | | | | - Maria Askmyr
- Department of Molecular Medicine and Gene Therapy, Lund Strategic Center for Stem Cell Biology, Lund University, Lund, Sweden
| | | | - Johan Richter
- Department of Molecular Medicine and Gene Therapy, Lund Strategic Center for Stem Cell Biology, Lund University, Lund, Sweden
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Capo V, Penna S, Merelli I, Barcella M, Scala S, Basso-Ricci L, Draghici E, Palagano E, Zonari E, Desantis G, Uva P, Cusano R, Sergi LS, Crisafulli L, Moshous D, Stepensky P, Drabko K, Kaya Z, Unal E, Gezdiric A, Menna G, Serafini M, Aiuti A, Locatelli SL, Carlo-Stella C, Schulz AS, Ficara F, Sobacchi C, Gentner B, Villa A. Expanded circulating hematopoietic stem/progenitor cells as novel cell source for the treatment of TCIRG1 osteopetrosis. Haematologica 2021; 106:74-86. [PMID: 31949009 PMCID: PMC7776247 DOI: 10.3324/haematol.2019.238261] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2019] [Accepted: 01/09/2020] [Indexed: 11/16/2022] Open
Abstract
Allogeneic hematopoietic stem cell transplantation is the treatment of choice for autosomal recessive osteopetrosis caused by defects in the TCIRG1 gene. Despite recent progress in conditioning, a relevant number of patients are not eligible for allogeneic stem cell transplantation because of the severity of the disease and significant transplant-related morbidity. We exploited peripheral CD34+ cells, known to circulate at high frequency in the peripheral blood of TCIRG1-deficient patients, as a novel cell source for autologous transplantation of gene corrected cells. Detailed phenotypical analysis showed that circulating CD34+ cells have a cellular composition that resembles bone marrow, supporting their use in gene therapy protocols. Transcriptomic profile revealed enrichment in genes expressed by hematopoietic stem and progenitor cells (HSPCs). To overcome the limit of bone marrow harvest/ HSPC mobilization and serial blood drawings in TCIRG1 patients, we applied UM171-based ex-vivo expansion of HSPCs coupled with lentiviral gene transfer. Circulating CD34+ cells from TCIRG1-defective patients were transduced with a clinically-optimized lentiviral vector (LV) expressing TCIRG1 under the control of phosphoglycerate promoter and expanded ex vivo. Expanded cells maintained long-term engraftment capacity and multi-lineage repopulating potential when transplanted in vivo both in primary and secondary NSG recipients. Moreover, when CD34+ cells were differentiated in vitro, genetically corrected osteoclasts resorbed the bone efficiently. Overall, we provide evidence that expansion of circulating HSPCs coupled to gene therapy can overcome the limit of stem cell harvest in osteopetrotic patients, thus opening the way to future gene-based treatment of skeletal diseases caused by bone marrow fibrosis.
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Affiliation(s)
- Valentina Capo
- San Raffaele Telethon Institute for Gene Therapy (SR-Tiget), IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Sara Penna
- San Raffaele Telethon Institute for Gene Therapy (SR-Tiget), IRCCS San Raffaele Scientific Institute, Milan, Italy
- DIMET, University of Milano-Bicocca, Monza, Italy
| | - Ivan Merelli
- Institute for Biomedical Technologies, National Research Council, Segrate, Italy
| | - Matteo Barcella
- San Raffaele Telethon Institute for Gene Therapy (SR-Tiget), IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Serena Scala
- San Raffaele Telethon Institute for Gene Therapy (SR-Tiget), IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Luca Basso-Ricci
- San Raffaele Telethon Institute for Gene Therapy (SR-Tiget), IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Elena Draghici
- San Raffaele Telethon Institute for Gene Therapy (SR-Tiget), IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Eleonora Palagano
- CNR-IRGB, Milan Unit, Milan, Italy
- Humanitas Clinical and Research Center - IRCCS, Rozzano, Italy
| | - Erika Zonari
- San Raffaele Telethon Institute for Gene Therapy (SR-Tiget), IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Giacomo Desantis
- San Raffaele Telethon Institute for Gene Therapy (SR-Tiget), IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Paolo Uva
- CRS4, Science and Technology Park Polaris, Pula, Italy
| | | | - Lucia Sergi Sergi
- San Raffaele Telethon Institute for Gene Therapy (SR-Tiget), IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Laura Crisafulli
- CNR-IRGB, Milan Unit, Milan, Italy
- Humanitas Clinical and Research Center - IRCCS, Rozzano, Italy
| | - Despina Moshous
- Unite d'Immunologie, Hematologie et Rhumatologie Pediatriques (UIHR), Assistance Publique-Hopitaux de Paris, Hopital Necker-Enfants Malades, Paris, France
- INSERM UMR1163, Institut Imagine, Universite Paris Descartes-Sorbonne Paris Cite, Paris, France
| | - Polina Stepensky
- Department of Bone Marrow Transplantation and Cancer Immunotherapy, Hadassah University Hospital, Jerusalem, Israel
| | | | - Zühre Kaya
- Department of Pediatric Hematology, Gazi University, School of Medicine, Ankara, Turkey
| | - Ekrem Unal
- Erciyes University, Pediatric Hematology Oncology, Kayseri, Turkey
- Molecular Biology and Genetic Department, Gevher Nesibe Genom and Stem Cell Institution, Genome and Stem Cell Center (GENKOK), Erciyes University, Kayseri, Turkey
| | - Alper Gezdiric
- Department of Medical Genetics, Istanbul Health Science University, Kanuni Sultan Suleyman Training and Research Hospital, Istanbul, Turkey
| | - Giuseppe Menna
- Hemato-Oncology Unit, Department of Oncology, Pausilipon Hospital, Naples, Italy
| | | | - Alessandro Aiuti
- San Raffaele Telethon Institute for Gene Therapy (SR-Tiget), IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Silvia Laura Locatelli
- Department of Oncology and Hematology, Humanitas Cancer Center, Humanitas Clinical and Research Center, Rozzano, Italy
| | - Carmelo Carlo-Stella
- Department of Oncology and Hematology, Humanitas Cancer Center, Humanitas Clinical and Research Center, Rozzano, Italy
- Department of Biomedical Sciences, Humanitas University, Rozzano, Italy
| | - Ansgar S. Schulz
- Department of Pediatrics and Adolescent Medicine, University Medical Center, Ulm, Germany
| | - Francesca Ficara
- CNR-IRGB, Milan Unit, Milan, Italy
- Humanitas Clinical and Research Center - IRCCS, Rozzano, Italy
| | - Cristina Sobacchi
- CNR-IRGB, Milan Unit, Milan, Italy
- Humanitas Clinical and Research Center - IRCCS, Rozzano, Italy
| | - Bernhard Gentner
- San Raffaele Telethon Institute for Gene Therapy (SR-Tiget), IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Anna Villa
- San Raffaele Telethon Institute for Gene Therapy (SR-Tiget), IRCCS San Raffaele Scientific Institute, Milan, Italy
- CNR-IRGB, Milan Unit, Milan, Italy
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Trajanoska K, Rivadeneira F. Genomic Medicine: Lessons Learned From Monogenic and Complex Bone Disorders. Front Endocrinol (Lausanne) 2020; 11:556610. [PMID: 33162933 PMCID: PMC7581702 DOI: 10.3389/fendo.2020.556610] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 08/21/2020] [Indexed: 12/11/2022] Open
Abstract
Current genetic studies of monogenic and complex bone diseases have broadened our understanding of disease pathophysiology, highlighting the need for medical interventions and treatments tailored to the characteristics of patients. As genomic research progresses, novel insights into the molecular mechanisms are starting to provide support to clinical decision-making; now offering ample opportunities for disease screening, diagnosis, prognosis and treatment. Drug targets holding mechanisms with genetic support are more likely to be successful. Therefore, implementing genetic information to the drug development process and a molecular redefinition of skeletal disease can help overcoming current shortcomings in pharmaceutical research, including failed attempts and appalling costs. This review summarizes the achievements of genetic studies in the bone field and their application to clinical care, illustrating the imminent advent of the genomic medicine era.
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Generation of an immunodeficient mouse model of tcirg1-deficient autosomal recessive osteopetrosis. Bone Rep 2020; 12:100242. [PMID: 31938717 PMCID: PMC6953598 DOI: 10.1016/j.bonr.2020.100242] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 12/23/2019] [Accepted: 01/04/2020] [Indexed: 01/16/2023] Open
Abstract
Background Autosomal recessive osteopetrosis is a rare skeletal disorder with increased bone density due to a failure in osteoclast bone resorption. In most cases, the defect is cell-autonomous, and >50% of patients bear mutations in the TCIRG1 gene, encoding for a subunit of the vacuolar proton pump essential for osteoclast resorptive activity. The only cure is hematopoietic stem cell transplantation, which corrects the bone pathology by allowing the formation of donor-derived functional osteoclasts. Therapeutic approaches using patient-derived cells corrected ex vivo through viral transduction or gene editing can be considered, but to date functional rescue cannot be demonstrated in vivo because a relevant animal model for xenotransplant is missing. Methods We generated a new mouse model, which we named NSG oc/oc, presenting severe autosomal recessive osteopetrosis owing to the Tcirg1oc mutation, and profound immunodeficiency caused by the NSG background. We performed neonatal murine bone marrow transplantation and xenotransplantation with human CD34+ cells. Results We demonstrated that neonatal murine bone marrow transplantation rescued NSG oc/oc mice, in line with previous findings in the oc/oc parental strain and with evidence from clinical practice in humans. Importantly, we also demonstrated human cell chimerism in the bone marrow of NSG oc/oc mice transplanted with human CD34+ cells. The severity and rapid progression of the disease in the mouse model prevented amelioration of the bone pathology; nevertheless, we cannot completely exclude that minor early modifications of the bone tissue might have occurred. Conclusion Our work paves the way to generating an improved xenograft model for in vivo evaluation of functional rescue of patient-derived corrected cells. Further refinement of the newly generated mouse model will allow capitalizing on it for an optimized exploitation in the path to novel cell therapies. Ex vivo corrected autologous HSCs might cure Autosomal Recessive Osteopetrosis (ARO). There is no animal model to prove in vivo functional rescue of corrected human cells. NSG oc/oc mice display osteoclast-rich cell-autonomous ARO and immunodeficiency. Human CD34+ cell-transplanted NSG oc/oc mice show human cell chimerism in the BM. Further improvements will allow in vivo evaluating corrected patient-derived cells.
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Ajmal M, Mir A, Wahid S, Khor CC, Foo JN, Siddiqi S, Kauser M, Malik SA, Nasir M. Identification and in silico characterization of a novel p.P208PfsX1 mutation in V-ATPase a3 subunit associated with autosomal recessive osteopetrosis in a Pakistani family. BMC MEDICAL GENETICS 2017; 18:148. [PMID: 29237407 PMCID: PMC5729456 DOI: 10.1186/s12881-017-0506-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Accepted: 11/29/2017] [Indexed: 11/15/2022]
Abstract
Background Osteopetrosis is a rare inherited bone disorder mainly described as an increased bone density caused by defective osteoclastic bone resorption. To date, genetic variants of eleven genes have been reported so far to be associated with different types of osteopetrosis. However, malignant infantile osteopetrosis, a lethal form of the disease, is mostly (50%) caused by mutation(s) in TCIRG1 gene. In this study, we investigated a consanguineous Pakistani family clinically and genetically to elucidate underlying molecular basis of the infantile osteopetrosis. Methods DNA samples from five family members were subjected to SNP-array based whole genome homozygosity mapping. Data was analyzed and potentially pathogenic mutation was identified by Sanger sequencing of two affected as well as three phenotypically healthy individuals in the family. The significance of identified pathogenic variation and its impact on protein structure and function was studied using various bioinformatics tools. Results DNA samples from five family members were subjected to genome-wide SNP array genotyping and homozygosity mapping which identified ~4 Mb region on chr11 harboring the TCIRG1 gene. Sanger sequencing unveiled a novel homozygous deletion c. 624delC in exon 6 of the TCIRG1 gene encodes a3 subunit of V-ATPase complex. The identified deletion resulted in a frame shift producing a truncated protein of 208 aa. In silico analysis of premature termination of the a3 subunit of V-ATPase complex revealed deleterious effects on the protein structure, predicting impaired or complete loss of V-ATPase function causing infantile osteopetrosis. Conclusions Since a3 subunit of V-ATPase complex plays a crucial role in bone resorption process, structurally abnormal a3 subunit might have adversely affected bone resorption process, leading to infantile osteopetrosis in Pakistani family. Therefore, the present study not only expands the genotypic spectrum of osteopetrosis but also improve understandings of the role of V-ATPase a3 subunit in bone resorption process. Moreover, our findings should help in genetic counseling and provide further insight into the disease pathogenesis and potential targeted therapy. Electronic supplementary material The online version of this article (10.1186/s12881-017-0506-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Muhammad Ajmal
- Institute of Biomedical and Genetic Engineering, 24-Mauve area, G-9/1, Islamabad, 44000, Pakistan
| | - Asif Mir
- Department of Biotechnology, International Islamic university, Islamabad, Pakistan
| | - Sughra Wahid
- KRL General Hospital, Pediatric Department 24-Mauve area, G-9/1, Islamabad, 44000, Pakistan
| | - Chiea Chuen Khor
- Human Genetics, Genome Institute of Singapore, A*STAR, Singapore, Singapore.,Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Jia Nee Foo
- Human Genetics, Genome Institute of Singapore, A*STAR, Singapore, Singapore.,Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| | - Saima Siddiqi
- Institute of Biomedical and Genetic Engineering, 24-Mauve area, G-9/1, Islamabad, 44000, Pakistan
| | - Mehran Kauser
- Institute of Biomedical and Genetic Engineering, 24-Mauve area, G-9/1, Islamabad, 44000, Pakistan
| | - Salman Akbar Malik
- Department of Biochemistry, Quaid-i-Azam University, Islamabad, 44000, Pakistan
| | - Muhammad Nasir
- Institute of Biomedical and Genetic Engineering, 24-Mauve area, G-9/1, Islamabad, 44000, Pakistan.
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Moscatelli I, Löfvall H, Schneider Thudium C, Rothe M, Montano C, Kertész Z, Sirin M, Schulz A, Schambach A, Henriksen K, Richter J. Targeting NSG Mice Engrafting Cells with a Clinically Applicable Lentiviral Vector Corrects Osteoclasts in Infantile Malignant Osteopetrosis. Hum Gene Ther 2017; 29:938-949. [PMID: 28726516 DOI: 10.1089/hum.2017.053] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Infantile malignant osteopetrosis (IMO) is a rare, lethal, autosomal recessive disorder characterized by nonfunctional osteoclasts. More than 50% of the patients have mutations in the TCIRG1 gene, encoding for a subunit of the osteoclast proton pump. The aim of this study was to develop a clinically applicable lentiviral vector expressing TCIRG1 to correct osteoclast function in IMO. Two mammalian promoters were compared: elongation factor 1α short (EFS) promoter and chimeric myeloid promoter (ChimP). EFS promoter was chosen for continued experiments, as it performed better. IMO osteoclasts corrected in vitro by a TCIRG1-expressing lentiviral vector driven by EFS (EFS-T) restored Ca2+ release to 92% and the levels of the bone degradation product CTX-I to 95% in the media compared to control osteoclasts. IMO CD34+ cells from five patients transduced with EFS-T were transplanted into NSG mice. Bone marrow was harvested 9-19 weeks after transplantation, and human CD34+ cells were selected, expanded, and seeded on bone slices. Vector-corrected IMO osteoclasts had completely restored Ca2+ release. CTX-I levels in the media were 33% compared to normal osteoclasts. Thus, in summary, evidence is provided that transduction of IMO CD34+ cells with the clinically applicable EFS-T vector leads to full rescue of osteoclasts in vitro and partial rescue of osteoclasts generated from NSG mice engrafting hematopoietic cells. This supports the continued clinical development of gene therapy for IMO.
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Affiliation(s)
- Ilana Moscatelli
- 1 Department of Molecular Medicine and Gene Therapy, Lund Strategic Center for Stem Cell Biology, Lund University , Lund, Sweden
| | - Henrik Löfvall
- 1 Department of Molecular Medicine and Gene Therapy, Lund Strategic Center for Stem Cell Biology, Lund University , Lund, Sweden.,2 Nordic Bioscience , Herlev, Denmark
| | | | - Michael Rothe
- 3 Institute of Experimental Hematology, Hannover Medical School , Hannover, Germany
| | - Carmen Montano
- 1 Department of Molecular Medicine and Gene Therapy, Lund Strategic Center for Stem Cell Biology, Lund University , Lund, Sweden
| | - Zsuzsanna Kertész
- 1 Department of Molecular Medicine and Gene Therapy, Lund Strategic Center for Stem Cell Biology, Lund University , Lund, Sweden
| | - Mehtap Sirin
- 4 Department of Pediatrics and Adolescent Medicine, University Medical Center , Ulm, Germany
| | - Ansgar Schulz
- 4 Department of Pediatrics and Adolescent Medicine, University Medical Center , Ulm, Germany
| | - Axel Schambach
- 3 Institute of Experimental Hematology, Hannover Medical School , Hannover, Germany
| | | | - Johan Richter
- 1 Department of Molecular Medicine and Gene Therapy, Lund Strategic Center for Stem Cell Biology, Lund University , Lund, Sweden
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11
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Montano Almendras CP, Thudium CS, Löfvall H, Moscatelli I, Schambach A, Henriksen K, Richter J. Forced expression of human macrophage colony-stimulating factor in CD34 + cells promotes monocyte differentiation in vitro and in vivo but blunts osteoclastogenesis in vitro. Eur J Haematol 2017; 98:517-526. [PMID: 28160330 DOI: 10.1111/ejh.12867] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/25/2017] [Indexed: 12/25/2022]
Abstract
OBJECTIVES Here, we tested the hypothesis that human M-CSF (hM-CSF) overexpressed in cord blood (CB) CD34+ cells would induce differentiation and survival of monocytes and osteoclasts in vitro and in vivo. METHODS Human M-CSF was overexpressed in cord blood CD34+ cells using a lentiviral vector. RESULTS We show that LV-hM-CSF-transduced CB CD34+ cells expand 3.6- and 8.5-fold more with one or two exposures to the hM-CSF-expressing vector, respectively, when compared to control cells. Likewise, LV-hM-CSF-transduced CB CD34+ cells show significantly higher levels of monocytes. In addition, these cells produced high levels of hM-CSF. Furthermore, they are able to differentiate into functional bone-resorbing osteoclasts in vitro. However, osteoclast differentiation and bone resorption were blunted compared to control CD34+ cells receiving exogenous hM-CSF. NSG mice engrafted with LV-hM-CSF-transduced CB CD34+ cells have physiological levels of hM-CSF production that result in an increase in the percentage of human monocytes in peripheral blood and bone marrow as well as in the spleen, lung and liver. CONCLUSION In summary, ectopic production of human M-CSF in CD34+ cells promotes cellular expansion and monocyte differentiation in vitro and in vivo and allows for the formation of functional osteoclasts, albeit at reduced levels, without an exogenous source of M-CSF, in vitro.
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Affiliation(s)
| | | | - Henrik Löfvall
- Department of Molecular Medicine and Gene Therapy, BMC A12, Lund University, Lund, Sweden.,Nordic Bioscience, Herlev, Denmark
| | - Ilana Moscatelli
- Department of Molecular Medicine and Gene Therapy, BMC A12, Lund University, Lund, Sweden
| | - Axel Schambach
- Institute of Experimental Hematology, Hannover Medical School, Hannover, Germany
| | | | - Johan Richter
- Department of Molecular Medicine and Gene Therapy, BMC A12, Lund University, Lund, Sweden
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12
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Thudium CS, Moscatelli I, Löfvall H, Kertész Z, Montano C, Bjurström CF, Karsdal MA, Schulz A, Richter J, Henriksen K. Regulation and Function of Lentiviral Vector-Mediated TCIRG1 Expression in Osteoclasts from Patients with Infantile Malignant Osteopetrosis: Implications for Gene Therapy. Calcif Tissue Int 2016; 99:638-648. [PMID: 27541021 DOI: 10.1007/s00223-016-0187-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 08/08/2016] [Indexed: 10/21/2022]
Abstract
Infantile malignant osteopetrosis (IMO) is a rare, recessive disorder characterized by increased bone mass caused by dysfunctional osteoclasts. The disease is most often caused by mutations in the TCIRG1 gene encoding a subunit of the V-ATPase involved in the osteoclasts capacity to resorb bone. We previously showed that osteoclast function can be restored by lentiviral vector-mediated expression of TCIRG1, but the exact threshold for restoration of resorption as well as the cellular response to vector-mediated TCIRG1 expression is unknown. Here we show that expression of TCIRG1 protein from a bicistronic TCIRG1/GFP lentiviral vector was only observed in mature osteoclasts, and not in their precursors or macrophages, in contrast to GFP expression, which was observed under all conditions. Thus, vector-mediated TCIRG1 expression appears to be post-transcriptionally regulated, preventing overexpression and/or ectopic expression and ensuring protein expression similar to that of wild-type osteoclasts. Codon optimization of TCIRG1 led to increased expression of mRNA but lower levels of protein and functional rescue. When assessing the functional rescue threshold in vitro, addition of 30 % CB CD34+ cells to IMO CD34+ patient cells was sufficient to completely normalize resorptive function after osteoclast differentiation. From both an efficacy and a safety perspective, these findings will clearly be of benefit during further development of gene therapy for osteopetrosis.
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Affiliation(s)
| | - Ilana Moscatelli
- Department of Molecular Medicine and Gene Therapy, Lund Strategic Center for Stem Cell Biology, BMC A12, 221 84, Lund, Sweden
| | - Henrik Löfvall
- Nordic Bioscience, Herlev, Denmark
- Department of Molecular Medicine and Gene Therapy, Lund Strategic Center for Stem Cell Biology, BMC A12, 221 84, Lund, Sweden
| | - Zsuzsanna Kertész
- Department of Molecular Medicine and Gene Therapy, Lund Strategic Center for Stem Cell Biology, BMC A12, 221 84, Lund, Sweden
| | - Carmen Montano
- Department of Molecular Medicine and Gene Therapy, Lund Strategic Center for Stem Cell Biology, BMC A12, 221 84, Lund, Sweden
| | - Carmen Flores Bjurström
- Department of Molecular Medicine and Gene Therapy, Lund Strategic Center for Stem Cell Biology, BMC A12, 221 84, Lund, Sweden
| | | | - Ansgar Schulz
- Department of Pediatrics and Adolescent Medicine, University Medical Center, Ulm, Germany
| | - Johan Richter
- Department of Molecular Medicine and Gene Therapy, Lund Strategic Center for Stem Cell Biology, BMC A12, 221 84, Lund, Sweden.
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13
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Imbrici P, Liantonio A, Camerino GM, De Bellis M, Camerino C, Mele A, Giustino A, Pierno S, De Luca A, Tricarico D, Desaphy JF, Conte D. Therapeutic Approaches to Genetic Ion Channelopathies and Perspectives in Drug Discovery. Front Pharmacol 2016; 7:121. [PMID: 27242528 PMCID: PMC4861771 DOI: 10.3389/fphar.2016.00121] [Citation(s) in RCA: 98] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2016] [Accepted: 04/25/2016] [Indexed: 12/21/2022] Open
Abstract
In the human genome more than 400 genes encode ion channels, which are transmembrane proteins mediating ion fluxes across membranes. Being expressed in all cell types, they are involved in almost all physiological processes, including sense perception, neurotransmission, muscle contraction, secretion, immune response, cell proliferation, and differentiation. Due to the widespread tissue distribution of ion channels and their physiological functions, mutations in genes encoding ion channel subunits, or their interacting proteins, are responsible for inherited ion channelopathies. These diseases can range from common to very rare disorders and their severity can be mild, disabling, or life-threatening. In spite of this, ion channels are the primary target of only about 5% of the marketed drugs suggesting their potential in drug discovery. The current review summarizes the therapeutic management of the principal ion channelopathies of central and peripheral nervous system, heart, kidney, bone, skeletal muscle and pancreas, resulting from mutations in calcium, sodium, potassium, and chloride ion channels. For most channelopathies the therapy is mainly empirical and symptomatic, often limited by lack of efficacy and tolerability for a significant number of patients. Other channelopathies can exploit ion channel targeted drugs, such as marketed sodium channel blockers. Developing new and more specific therapeutic approaches is therefore required. To this aim, a major advancement in the pharmacotherapy of channelopathies has been the discovery that ion channel mutations lead to change in biophysics that can in turn specifically modify the sensitivity to drugs: this opens the way to a pharmacogenetics strategy, allowing the development of a personalized therapy with increased efficacy and reduced side effects. In addition, the identification of disease modifiers in ion channelopathies appears an alternative strategy to discover novel druggable targets.
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Affiliation(s)
- Paola Imbrici
- Department of Pharmacy - Drug Sciences, University of Bari "Aldo Moro" Bari, Italy
| | - Antonella Liantonio
- Department of Pharmacy - Drug Sciences, University of Bari "Aldo Moro" Bari, Italy
| | - Giulia M Camerino
- Department of Pharmacy - Drug Sciences, University of Bari "Aldo Moro" Bari, Italy
| | - Michela De Bellis
- Department of Pharmacy - Drug Sciences, University of Bari "Aldo Moro" Bari, Italy
| | - Claudia Camerino
- Department of Basic Medical Sciences, Neurosciences and Sense Organs, University of Bari "Aldo Moro" Bari, Italy
| | - Antonietta Mele
- Department of Pharmacy - Drug Sciences, University of Bari "Aldo Moro" Bari, Italy
| | - Arcangela Giustino
- Department of Biomedical Sciences and Human Oncology, University of Bari "Aldo Moro" Bari, Italy
| | - Sabata Pierno
- Department of Pharmacy - Drug Sciences, University of Bari "Aldo Moro" Bari, Italy
| | - Annamaria De Luca
- Department of Pharmacy - Drug Sciences, University of Bari "Aldo Moro" Bari, Italy
| | - Domenico Tricarico
- Department of Pharmacy - Drug Sciences, University of Bari "Aldo Moro" Bari, Italy
| | - Jean-Francois Desaphy
- Department of Biomedical Sciences and Human Oncology, University of Bari "Aldo Moro" Bari, Italy
| | - Diana Conte
- Department of Pharmacy - Drug Sciences, University of Bari "Aldo Moro" Bari, Italy
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14
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Sobacchi C, Pangrazio A, Lopez AGM, Gomez DPV, Caldana ME, Susani L, Vezzoni P, Villa A. As little as needed: the extraordinary case of a mild recessive osteopetrosis owing to a novel splicing hypomorphic mutation in the TCIRG1 gene. J Bone Miner Res 2014; 29:1646-50. [PMID: 24535816 PMCID: PMC4258090 DOI: 10.1002/jbmr.2203] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Revised: 01/23/2014] [Accepted: 02/09/2014] [Indexed: 01/22/2023]
Abstract
Mutations in the TCIRG1 gene, coding for a subunit of the osteoclast proton pump, are responsible for more than 50% of cases of human malignant autosomal recessive osteopetrosis (ARO), a rare inherited bone disease with increased bone density owing to a failure in bone resorption. A wide variety of mutations has been described, including missense, nonsense, small deletions/insertions, splice-site mutations, and large genomic deletions, all leading to a similar severe presentation. So far, to the best of our knowledge, no report of a mild phenotype owing to recessive TCIRG1 mutations is present neither in our series of more than 100 TCIRG1-dependent ARO patients nor in the literature. Here we describe an 8-year-old patient referred to us with a clinical diagnosis of ARO, based on radiological findings; of note, no neurological or hematological defects were present in this girl. Surprisingly, we identified a novel nucleotide change in intron 15 of the TCIRG1 gene at the homozygous state, leading to the production of multiple aberrant transcripts, but also, more importantly, of a limited amount of the normal transcript. Our results show that a low level of normal TCIRG1 protein can dampen the clinical presentation of TCIRG1-dependent ARO. On this basis, a small amount of protein might be sufficient to rescue, at least partially, the severe ARO phenotype, and this is particularly important when gene therapy approaches are considered. In addition, we would also recommend that the TCIRG1 gene be included in the molecular diagnosis of mild forms of human ARO.
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Affiliation(s)
- Cristina Sobacchi
- Unitá Operativa di Supporto (UOS)/Institute of Genetic and Biomedical Research (IRGB), Milan Unit, National Research Council (CNR), Milan, Italy; Humanitas Clinical and Research Center, Rozzano, Italy
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15
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Thudium CS, Moscatelli I, Flores C, Thomsen JS, Brüel A, Gudmann NS, Hauge EM, Karsdal MA, Richter J, Henriksen K. A comparison of osteoclast-rich and osteoclast-poor osteopetrosis in adult mice sheds light on the role of the osteoclast in coupling bone resorption and bone formation. Calcif Tissue Int 2014; 95:83-93. [PMID: 24838599 DOI: 10.1007/s00223-014-9865-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Accepted: 04/28/2014] [Indexed: 01/15/2023]
Abstract
Osteopetrosis due to lack of acid secretion by osteoclasts is characterized by abolished bone resorption, increased osteoclast numbers, but normal or even increased bone formation. In contrast, osteoclast-poor osteopetrosis appears to have less osteoblasts and reduced bone formation, indicating that osteoclasts are important for regulating osteoblast activity. To illuminate the role of the osteoclast in controlling bone remodeling, we transplanted irradiated skeletally mature 3-month old wild-type mice with hematopoietic stem cells (HSCs) to generate either an osteoclast-rich or osteoclast-poor adult osteopetrosis model. We used fetal liver HSCs from (1) oc/oc mice, (2) RANK KO mice, and (3) compared these to wt control cells. TRAP5b activity, a marker of osteoclast number and size, was increased in the oc/oc recipients, while a significant reduction was seen in the RANK KO recipients. In contrast, the bone resorption marker CTX-I was similarly decreased in both groups. Both oc/oc and Rank KO recipients developed a mild osteopetrotic phenotype. However, the osteoclast-rich oc/oc recipients showed higher trabecular bone volume (40 %), increased bone strength (66 %), and increased bone formation rate (54 %) in trabecular bone, while RANK KO recipients showed only minor trends compared to control recipients. We here show that maintaining non-resorbing osteoclasts, as opposed to reducing the osteoclasts, leads to increased bone formation, bone volume, and ultimately higher bone strength in vivo, which indicates that osteoclasts are sources of anabolic molecules for the osteoblasts.
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