1
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Liu Y, Tan D, Ma K, Luo H, Mao J, Luo J, Shen Q, Xu L, Yang S, Ge L, Guo Y, Zhang H, Xiong H. Lama1 upregulation prolongs the lifespan of the dy H/dy H mouse model of LAMA2-related congenital muscular dystrophy. J Genet Genomics 2024:S1673-8527(24)00118-8. [PMID: 38777118 DOI: 10.1016/j.jgg.2024.05.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2024] [Revised: 05/17/2024] [Accepted: 05/18/2024] [Indexed: 05/25/2024]
Abstract
LAMA2-related congenital muscular dystrophy (LAMA2-CMD), characterized by laminin-α2 deficiency, is debilitating and ultimately fatal. To date, no effective therapy has been clinically available. Laminin-α1, which shares significant similarities with laminin-α2, has been proven as a viable compensatory modifier. To evaluate its clinical applicability, we establish a Lama2 exon-3 deletion mouse model (dyH/dyH). The dyH/dyH mice exhibit early lethality and typical LAMA2-CMD phenotypes, allowing the evaluation of various endpoints. In dyH/dyH mice treated with synergistic activation mediator-based CRISPRa-mediated Lama1 upregulation, a nearly doubled median survival is observed, as well as improvements in weight and grip. Significant therapeutical effects are revealed by MRI, serum biochemical indices, and muscle pathology studies. Treating LAMA2-CMD with LAMA1 upregulation is feasible and that early intervention can alleviate symptoms and extend lifespan. Additionally, we reveal limitations of LAMA1 upregulation, including high-dose mortality and non-sustained expression, which require further optimization in future studies.
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Affiliation(s)
- Yidan Liu
- Department of Pediatrics, Peking University First Hospital, Beijing 102600, China; State Key Laboratory of Vascular Homeostasis and Remodeling, The Institute of Cardiovascular Sciences, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Dandan Tan
- Department of Pediatrics, Peking University First Hospital, Beijing 102600, China; Department of Neurology, The First Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang, Jiangxi 330006, China
| | - Kaiyue Ma
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai 200030, China; Department of Genetics, Yale School of Medicine, New Haven, CT 06510, USA
| | - Huaxia Luo
- Department of Pediatrics, Peking University First Hospital, Beijing 102600, China
| | - Jingping Mao
- State Key Laboratory of Vascular Homeostasis and Remodeling, The Institute of Cardiovascular Sciences, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Jihang Luo
- Department of Pediatrics, Peking University First Hospital, Beijing 102600, China; State Key Laboratory of Vascular Homeostasis and Remodeling, The Institute of Cardiovascular Sciences, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Qiang Shen
- State Key Laboratory of Vascular Homeostasis and Remodeling, The Institute of Cardiovascular Sciences, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Luzheng Xu
- Medical and Health Analysis Center, Peking University, Beijing 100191, China
| | - Shiqi Yang
- Department of Pediatrics, Peking University First Hospital, Beijing 102600, China; State Key Laboratory of Vascular Homeostasis and Remodeling, The Institute of Cardiovascular Sciences, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Lin Ge
- Department of Genetics, Yale School of Medicine, New Haven, CT 06510, USA; Department of Neurology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing 100045, China
| | - Yuxuan Guo
- State Key Laboratory of Vascular Homeostasis and Remodeling, The Institute of Cardiovascular Sciences, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China.
| | - Hong Zhang
- State Key Laboratory of Vascular Homeostasis and Remodeling, The Institute of Cardiovascular Sciences, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China.
| | - Hui Xiong
- Department of Pediatrics, Peking University First Hospital, Beijing 102600, China; Department of Neurology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing 100045, China.
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2
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Germain T, Truong C, Oudre L, Krejci E. Unsupervised classification of plethysmography signals with advanced visual representations. Front Physiol 2023; 14:1154328. [PMID: 37288430 PMCID: PMC10242092 DOI: 10.3389/fphys.2023.1154328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 04/28/2023] [Indexed: 06/09/2023] Open
Abstract
Ventilation is a simple physiological function that ensures the vital supply of oxygen and the elimination of CO2. The recording of the airflow through the nostrils of a mouse over time makes it possible to calculate the position of critical points, based on the shape of the signals, to compute the respiratory frequency and the volume of air exchanged. These descriptors only account for a part of the dynamics of respiratory exchanges. In this work we present a new algorithm that directly compares the shapes of signals and considers meaningful information about the breathing dynamics omitted by the previous descriptors. The algorithm leads to a new classification of inspiration and expiration, which reveals that mice respond and adapt differently to inhibition of cholinesterases, enzymes targeted by nerve gas, pesticide, or drug intoxication.
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Affiliation(s)
- Thibaut Germain
- Université Paris Saclay, Université Paris Cité, ENS Paris Saclay, CNRS, SSA, INSERM, Centre Borelli, Gif-sur-Yvette, France
| | - Charles Truong
- Université Paris Saclay, Université Paris Cité, ENS Paris Saclay, CNRS, SSA, INSERM, Centre Borelli, Gif-sur-Yvette, France
| | - Laurent Oudre
- Université Paris Saclay, Université Paris Cité, ENS Paris Saclay, CNRS, SSA, INSERM, Centre Borelli, Gif-sur-Yvette, France
| | - Eric Krejci
- Université Paris Cité, Université Paris Saclay, ENS Paris Saclay, CNRS, SSA, INSERM, Centre Borelli, Paris, France
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3
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Barraza-Flores P, Bukovec KE, Dagda M, Conner BW, Oliveira-Santos A, Grange RW, Burkin DJ. Laminin-111 protein therapy after disease onset slows muscle disease in a mouse model of laminin-α2 related congenital muscular dystrophy. Hum Mol Genet 2021; 29:2162-2170. [PMID: 32472139 DOI: 10.1093/hmg/ddaa104] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 05/03/2020] [Accepted: 05/27/2020] [Indexed: 12/11/2022] Open
Abstract
Laminin-α2 related congenital muscular dystrophy (LAMA2-CMD) is a fatal muscle disease caused by mutations in the LAMA2 gene. Laminin-α2 is critical for the formation of laminin-211 and -221 heterotrimers in the muscle basal lamina. LAMA2-CMD patients exhibit hypotonia from birth and progressive muscle loss that results in developmental delay, confinement to a wheelchair, respiratory insufficiency and premature death. There is currently no cure or effective treatment for LAMA2-CMD. Several studies have shown laminin-111 can serve as an effective protein-replacement therapy for LAMA2-CMD. Studies have demonstrated early treatment with laminin-111 protein results in an increase in life expectancy and improvements in muscle pathology and function. Since LAMA2-CMD patients are often diagnosed after advanced disease, it is unclear if laminin-111 protein therapy at an advanced stage of the disease can have beneficial outcomes. In this study, we tested the efficacy of laminin-111 protein therapy after disease onset in a mouse model of LAMA2-CMD. Our results showed laminin-111 treatment after muscle disease onset increased life expectancy, promoted muscle growth and increased muscle stiffness. Together these studies indicate laminin-111 protein therapy either early or late in the disease process could serve as an effective protein replacement therapy for LAMA2-CMD.
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Affiliation(s)
- Pamela Barraza-Flores
- Department of Pharmacology, Reno School of Medicine, University of Nevada, Reno, NV 89557, USA
| | - Katherine E Bukovec
- Department of Human Nutrition, Foods, and Exercise, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Marisela Dagda
- Department of Pharmacology, Reno School of Medicine, University of Nevada, Reno, NV 89557, USA
| | - Brandon W Conner
- Department of Pharmacology, Reno School of Medicine, University of Nevada, Reno, NV 89557, USA
| | - Ariany Oliveira-Santos
- Department of Pharmacology, Reno School of Medicine, University of Nevada, Reno, NV 89557, USA
| | - Robert W Grange
- Department of Human Nutrition, Foods, and Exercise, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Dean J Burkin
- Department of Pharmacology, Reno School of Medicine, University of Nevada, Reno, NV 89557, USA
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4
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Packer D, Martin PT. Micro-laminin gene therapy can function as an inhibitor of muscle disease in the dy W mouse model of MDC1A. Mol Ther Methods Clin Dev 2021; 21:274-287. [PMID: 33869655 PMCID: PMC8026908 DOI: 10.1016/j.omtm.2021.02.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 02/03/2021] [Indexed: 02/04/2023]
Abstract
Gene replacement for laminin-α2-deficient congenital muscular dystrophy 1A (MDC1A) is currently not possible using a single adeno-associated virus (AAV) vector due to the large size of the LAMA2 gene. LAMA2 encodes laminin-α2, a subunit of the trimeric laminin-211 extracellular matrix (ECM) protein that is the predominant laminin expressed in skeletal muscle. LAMA2 expression stabilizes skeletal muscle, in part by binding membrane receptors via its five globular (G) domains. We created a small, AAV-deliverable, micro-laminin gene therapy that expresses these G1-5 domains, LAMA2(G1-5), to test their therapeutic efficacy in the dyW mouse model for MDC1A. We also fused the heparin-binding (HB) domain from HB epidermal growth factor-like growth factor (HB-EGF) to LAMA2(G1-5) to test whether this would increase muscle ECM expression. dyW mice treated intravenously with rAAV9.CMV.HB-LAMA2(G1-5) showed increased muscle ECM expression of transgenic protein relative to mice treated with rAAV9.CMV.LAMA2(G1-5) and showed improved weight-normalized forelimb grip strength relative to untreated dyW mice. Additionally, dyW muscle fibers expressing either micro-laminin protein showed some measures of reduced pathology, although levels of muscle cell apoptosis and inflammation were not decreased. Although systemic expression of rAAV9.CMV.HB-LAMA2(G1-5) did not inhibit all disease phenotypes, these studies demonstrate the feasibility of using a micro-laminin gene therapy strategy to deliver gene replacement for MDC1A.
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Affiliation(s)
- Davin Packer
- Neuroscience Graduate Program, The Ohio State University, Columbus, OH, USA
- Center for Gene Therapy, Abigail Wexner Research Institute, The Research Institute at Nationwide Children’s Hospital, Columbus, OH, USA
| | - Paul T. Martin
- Center for Gene Therapy, Abigail Wexner Research Institute, The Research Institute at Nationwide Children’s Hospital, Columbus, OH, USA
- Department of Pediatrics, The Ohio State University College of Medicine, Columbus, OH, USA
- Corresponding author Paul T. Martin, Center for Gene Therapy, Abigail Wexner Research Institute, The Research Institute at Nationwide Children’s Hospital, 700 Children’s Drive, Columbus, OH 43209, USA.
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5
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Fabian L, Dowling JJ. Zebrafish Models of LAMA2-Related Congenital Muscular Dystrophy (MDC1A). Front Mol Neurosci 2020; 13:122. [PMID: 32742259 PMCID: PMC7364686 DOI: 10.3389/fnmol.2020.00122] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 06/11/2020] [Indexed: 01/28/2023] Open
Abstract
LAMA2-related congenital muscular dystrophy (CMD; LAMA2-MD), also referred to as merosin deficient CMD (MDC1A), is a severe neonatal onset muscle disease caused by recessive mutations in the LAMA2 gene. LAMA2 encodes laminin α2, a subunit of the extracellular matrix (ECM) oligomer laminin 211. There are currently no treatments for MDC1A, and there is an incomplete understanding of disease pathogenesis. Zebrafish, due to their high degree of genetic conservation with humans, large clutch sizes, rapid development, and optical clarity, have emerged as an excellent model system for studying rare Mendelian diseases. They are particularly suitable as a model for muscular dystrophy because they contain at least one orthologue to all major human MD genes, have muscle that is similar to human muscle in structure and function, and manifest obvious and easily measured MD related phenotypes. In this review article, we present the existing zebrafish models of MDC1A, and discuss their contribution to the understanding of MDC1A pathomechanisms and therapy development.
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Affiliation(s)
- Lacramioara Fabian
- Program for Genetics and Genome Biology, Hospital for Sick Children, Toronto, ON, Canada
| | - James J Dowling
- Program for Genetics and Genome Biology, Hospital for Sick Children, Toronto, ON, Canada.,Division of Neurology, Hospital for Sick Children, Toronto, ON, Canada.,Departments of Pediatrics and Molecular Genetics, University of Toronto, Toronto, ON, Canada
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6
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Arreguin AJ, Colognato H. Brain Dysfunction in LAMA2-Related Congenital Muscular Dystrophy: Lessons From Human Case Reports and Mouse Models. Front Mol Neurosci 2020; 13:118. [PMID: 32792907 PMCID: PMC7390928 DOI: 10.3389/fnmol.2020.00118] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 06/09/2020] [Indexed: 12/26/2022] Open
Abstract
Laminin α2 gene (LAMA2)-related Congenital Muscular Dystrophy (CMD) was distinguished by a defining central nervous system (CNS) abnormality—aberrant white matter signals by MRI—when first described in the 1990s. In the past 25 years, researchers and clinicians have expanded our knowledge of brain involvement in LAMA2-related CMD, also known as Congenital Muscular Dystrophy Type 1A (MDC1A). Neurological changes in MDC1A can be structural, including lissencephaly and agyria, as well as functional, including epilepsy and intellectual disability. Mouse models of MDC1A include both spontaneous and targeted LAMA2 mutations and range from a partial loss of LAMA2 function (e.g., dy2J/dy2J), to a complete loss of LAMA2 expression (dy3K/dy3K). Diverse cellular and molecular changes have been reported in the brains of MDC1A mouse models, including blood-brain barrier dysfunction, altered neuro- and gliogenesis, changes in synaptic plasticity, and decreased myelination, providing mechanistic insight into potential neurological dysfunction in MDC1A. In this review article, we discuss selected studies that illustrate the potential scope and complexity of disturbances in brain development in MDC1A, and as well as highlight mechanistic insights that are emerging from mouse models.
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Affiliation(s)
- Andrea J Arreguin
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY, United States.,Medical Scientist Training Program (MSTP), Stony Brook University, Stony Brook, NY, United States
| | - Holly Colognato
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY, United States
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7
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Gawlik KI, Durbeej M. A Family of Laminin α2 Chain-Deficient Mouse Mutants: Advancing the Research on LAMA2-CMD. Front Mol Neurosci 2020; 13:59. [PMID: 32457577 PMCID: PMC7188397 DOI: 10.3389/fnmol.2020.00059] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 03/26/2020] [Indexed: 12/11/2022] Open
Abstract
The research on laminin α2 chain-deficient congenital muscular dystrophy (LAMA2-CMD) advanced rapidly in the last few decades, largely due to availability of good mouse models for the disease and a strong interest in preclinical studies from scientists all over the world. These mouse models continue to provide a solid platform for understanding the LAMA2-CMD pathology. In addition, they enable researchers to test laborious, necessary routines, but also the most creative scientific approaches in order to design therapy for this devastating disorder. In this review we present animals belonging to the laminin α2 chain-deficient “dy/dy” mouse family (dy/dy, dy2J/dy2J, dy3K/dy3K, dyW/dyW, et al.) and a summary of the scientific progress they facilitated. We also raise a few questions that need to be addressed in order to maximize the usefulness of laminin α2 murine mutants and to further advance the LAMA2-CMD studies. We believe that research opportunities offered by the mouse models for LAMA2-CMD will continuously support our efforts to find a treatment for the disease.
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Affiliation(s)
- Kinga I Gawlik
- Muscle Biology Unit, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Madeleine Durbeej
- Muscle Biology Unit, Department of Experimental Medical Science, Lund University, Lund, Sweden
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8
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van Putten M, Lloyd EM, de Greef JC, Raz V, Willmann R, Grounds MD. Mouse models for muscular dystrophies: an overview. Dis Model Mech 2020; 13:dmm043562. [PMID: 32224495 PMCID: PMC7044454 DOI: 10.1242/dmm.043562] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Muscular dystrophies (MDs) encompass a wide variety of inherited disorders that are characterized by loss of muscle tissue associated with a progressive reduction in muscle function. With a cure lacking for MDs, preclinical developments of therapeutic approaches depend on well-characterized animal models that recapitulate the specific pathology in patients. The mouse is the most widely and extensively used model for MDs, and it has played a key role in our understanding of the molecular mechanisms underlying MD pathogenesis. This has enabled the development of therapeutic strategies. Owing to advancements in genetic engineering, a wide variety of mouse models are available for the majority of MDs. Here, we summarize the characteristics of the most commonly used mouse models for a subset of highly studied MDs, collated into a table. Together with references to key publications describing these models, this brief but detailed overview would be useful for those interested in, or working with, mouse models of MD.
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Affiliation(s)
- Maaike van Putten
- Leiden University Medical Center, Department of Human Genetics, Leiden, 2333 ZA, The Netherlands
| | - Erin M Lloyd
- The University of Western Australia, School of Human Sciences, Perth 6009, Australia
| | - Jessica C de Greef
- Leiden University Medical Center, Department of Human Genetics, Leiden, 2333 ZA, The Netherlands
| | - Vered Raz
- Leiden University Medical Center, Department of Human Genetics, Leiden, 2333 ZA, The Netherlands
| | | | - Miranda D Grounds
- The University of Western Australia, School of Human Sciences, Perth 6009, Australia
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9
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Nguyen Q, Lim KRQ, Yokota T. Current understanding and treatment of cardiac and skeletal muscle pathology in laminin-α2 chain-deficient congenital muscular dystrophy. APPLICATION OF CLINICAL GENETICS 2019; 12:113-130. [PMID: 31308722 PMCID: PMC6618038 DOI: 10.2147/tacg.s187481] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 05/08/2019] [Indexed: 01/04/2023]
Abstract
Congenital muscular dystrophy (CMD) is a class of severe early-onset muscular dystrophies affecting skeletal/cardiac muscles as well as the central nervous system (CNS). Laminin-α2 chain-deficient congenital muscular dystrophy (LAMA2 MD), also known as merosin-deficient congenital muscular dystrophy type 1A (MDC1A), is an autosomal recessive CMD characterized by severe muscle weakness and degeneration apparent at birth or in the first 6 months of life. LAMA2 MD is the most common congenital muscular dystrophy, affecting approximately 4 in 500,000 children. The most common cause of death in early-onset LAMA2 MD is respiratory tract infection, with 30% of them dying within the first decade of life. LAMA2 MD is caused by loss-of-function mutations in the LAMA2 gene encoding for the laminin-α2 chain, one of the subunits of laminin-211. Laminin-211 is an extracellular matrix protein that functions to stabilize the basement membrane and muscle fibers during contraction. Since laminin-α2 is expressed in many tissue types including skeletal muscle, cardiac muscle, Schwann cells, and trophoblasts, patients with LAMA2 MD experience a multi-systemic clinical presentation depending on the extent of laminin-α2 chain deficiency. Cardiac manifestations are typically associated with a complete absence of laminin-α2; however, recent case reports highlight cardiac involvement in partial laminin-α2 chain deficiency. Laminin-211 is also expressed in the brain, and many patients have abnormalities on brain imaging; however, mental retardation and/or seizures are rarely seen. Currently, there is no cure for LAMA2 MD, but various therapies are being investigated in an effort to lessen the severity of LAMA2 MD. For example, antisense oligonucleotide-mediated exon skipping and CRISPR-Cas9 genome editing have efficiently restored the laminin-α2 chain in mouse models in vivo. This review consolidates information on the clinical presentation, genetic basis, pathology, and current treatment approaches for LAMA2 MD.
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Affiliation(s)
- Quynh Nguyen
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Kenji Rowel Q Lim
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Toshifumi Yokota
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada.,The Friends of Garrett Cumming Research & Muscular Dystrophy Canada, HM Toupin Neurological Science Research Chair, Edmonton, AB, Canada
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10
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Yurchenco PD, McKee KK, Reinhard JR, Rüegg MA. Laminin-deficient muscular dystrophy: Molecular pathogenesis and structural repair strategies. Matrix Biol 2017; 71-72:174-187. [PMID: 29191403 DOI: 10.1016/j.matbio.2017.11.009] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 11/15/2017] [Accepted: 11/16/2017] [Indexed: 12/19/2022]
Abstract
Laminins are large heterotrimers composed of the α, β and γ subunits with distinct tissue-specific and developmentally regulated expression patterns. The laminin-α2 subunit, encoded by the LAMA2 gene, is expressed in skeletal muscle, Schwann cells of the peripheral nerve and astrocytes and pericytes of the capillaries in the brain. Mutations in LAMA2 cause the most common type of congenital muscular dystrophies, called LAMA2 MD or MDC1A. The disorder manifests mostly as a muscular dystrophy but slowing of nerve conduction contributes to the disease. There are severe, non-ambulatory or milder, ambulatory variants, the latter resulting from reduced laminin-α2 expression and/or deficient laminin-α2 function. Lm-211 (α2β1γ1) is responsible for initiating basement membrane assembly. This is primarily accomplished by anchorage of Lm-211 to dystroglycan and α7β1 integrin receptors, polymerization, and binding to nidogen and other structural components. In LAMA2 MD, Lm-411 replaces Lm-211; however, Lm-411 lacks the ability to polymerize and bind to receptors. This results in a weakened basement membrane leading to the disease. The possibility of introducing structural repair proteins that correct the underlying abnormality is an attractive therapeutic goal. Recent studies in mouse models for LAMA2 MD reveal that introduction of laminin-binding linker proteins that restore lost functional activities can substantially ameliorate the disease. This review discusses the underlying mechanism of this repair and compares this approach to other developing therapies employing pharmacological treatments.
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Affiliation(s)
- Peter D Yurchenco
- Dept. Pathology & Laboratory Medicine, Rutgers University, Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA.
| | - Karen K McKee
- Dept. Pathology & Laboratory Medicine, Rutgers University, Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA
| | | | - Markus A Rüegg
- Biozentrum, University of Basel, 4056 Basel, Switzerland.
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