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Jahncke JN, Miller DS, Krush M, Schnell E, Wright KM. Inhibitory CCK+ basket synapse defects in mouse models of dystroglycanopathy. eLife 2024; 12:RP87965. [PMID: 38179984 PMCID: PMC10942650 DOI: 10.7554/elife.87965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2024] Open
Abstract
Dystroglycan (Dag1) is a transmembrane glycoprotein that links the extracellular matrix to the actin cytoskeleton. Mutations in Dag1 or the genes required for its glycosylation result in dystroglycanopathy, a type of congenital muscular dystrophy characterized by a wide range of phenotypes including muscle weakness, brain defects, and cognitive impairment. We investigated interneuron (IN) development, synaptic function, and associated seizure susceptibility in multiple mouse models that reflect the wide phenotypic range of dystroglycanopathy neuropathology. Mice that model severe dystroglycanopathy due to forebrain deletion of Dag1 or Pomt2, which is required for Dystroglycan glycosylation, show significant impairment of CCK+/CB1R+ IN development. CCK+/CB1R+ IN axons failed to properly target the somatodendritic compartment of pyramidal neurons in the hippocampus, resulting in synaptic defects and increased seizure susceptibility. Mice lacking the intracellular domain of Dystroglycan have milder defects in CCK+/CB1R+ IN axon targeting, but exhibit dramatic changes in inhibitory synaptic function, indicating a critical postsynaptic role of this domain. In contrast, CCK+/CB1R+ IN synaptic function and seizure susceptibility was normal in mice that model mild dystroglycanopathy due to partially reduced Dystroglycan glycosylation. Collectively, these data show that inhibitory synaptic defects and elevated seizure susceptibility are hallmarks of severe dystroglycanopathy, and show that Dystroglycan plays an important role in organizing functional inhibitory synapse assembly.
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Affiliation(s)
- Jennifer N Jahncke
- Neuroscience Graduate Program, Oregon Health & Science UniversityPortlandUnited States
| | - Daniel S Miller
- Neuroscience Graduate Program, Oregon Health & Science UniversityPortlandUnited States
| | - Milana Krush
- Neuroscience Graduate Program, Oregon Health & Science UniversityPortlandUnited States
| | - Eric Schnell
- Operative Care Division, Portland VA Health Care SystemPortlandUnited States
- Anesthesiology and Perioperative Medicine, Oregon Health & Science UniversityPortlandUnited States
| | - Kevin M Wright
- Vollum Institute, Oregon Health & Science UniversityPortlandUnited States
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Lu QL, Holbrook MC, Cataldi MP, Blaeser A. Break Down of the Complexity and Inconsistency Between Levels of Matriglycan and Disease Phenotype in FKRP-Related Dystroglycanopathies: A Review and Model of Interpretation. J Neuromuscul Dis 2024; 11:275-284. [PMID: 38277301 DOI: 10.3233/jnd-230205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2024]
Abstract
Dystroglycanopathies are a group of muscle degenerative diseases characterized with significant reduction in matriglycan expression critical in disease pathogenesis. Missense point mutations in the Fukutin-related protein (FKRP) gene cause variable reduction in the synthesis of matriglycan on alpha-dystroglycan (α-DG) and a wide range of disease severity. Data analyses of muscle biopsies from patients fail to show consistent correlation between the levels of matriglycan and clinical phenotypes. By reviewing clinical reports in conjunction with analysis of clinically relevant mouse models, we identify likely causes for the confusion. Nearly all missense FKRP mutations retain variable, but sufficient function for the synthesis of matriglycan during the later stage of muscle development and periods of muscle regeneration. These factors lead to a highly heterogenous pattern of matriglycan expression in diseased muscles, depending on age and stages of muscle regeneration. The limited size in clinical biopsy samples from different parts of even a single muscle tissue at different time points of disease progression may well mis-represent the residual function (base-levels) of the mutated FKRPs and phenotypes. We propose to use a simple Multi Point tool from ImageJ to more accurately measure the signal intensity of matriglycan expression on fiber membrane for assessing mutant FKRP function and therapeutic efficacy. A robust and sensitive immunohistochemical protocol would further improve reliability and comparability for the detection of matriglycan.
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Affiliation(s)
- Qi L Lu
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Carolinas Medical Center, Atrium Health, Charlotte, NC, USA
| | - Molly C Holbrook
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Carolinas Medical Center, Atrium Health, Charlotte, NC, USA
| | - Marcela P Cataldi
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Carolinas Medical Center, Atrium Health, Charlotte, NC, USA
| | - Anthony Blaeser
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Carolinas Medical Center, Atrium Health, Charlotte, NC, USA
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Cataldi MP, Vannoy CH, Blaeser A, Tucker JD, Leroy V, Rawls R, Killilee J, Holbrook MC, Lu QL. Improved efficacy of FKRP AAV gene therapy by combination with ribitol treatment for LGMD2I. Mol Ther 2023; 31:3478-3489. [PMID: 37919902 PMCID: PMC10727973 DOI: 10.1016/j.ymthe.2023.10.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 10/05/2023] [Accepted: 10/31/2023] [Indexed: 11/04/2023] Open
Abstract
Mutations in the fukutin-related protein (FKRP) gene cause dystroglycanopathy, with disease severity ranging from mild LGMD2I to severe congenital muscular dystrophy. Recently, considerable progress has been made in developing experimental therapies, with adeno-associated virus (AAV) gene therapy and ribitol treatment demonstrating significant therapeutic effect. However, each treatment has its strengths and weaknesses. AAV gene therapy can achieve normal levels of transgene expression, but it requires high doses, with toxicity concerns and variable distribution. Ribitol relies on residual FKRP function and restores limited levels of matriglycan. We hypothesized that these two treatments can work synergistically to offer an optimized therapy with efficacy and safety unmatched by each treatment alone. The most effective treatment is the combination of high-dose (5e-13 vg/kg) AAV-FKRP with ribitol, whereas low dose (1e-13 vg/kg) AAV-FKRP combined with ribitol showed a 22.6% increase in positive matriglycan fibers and the greater improvement in pathology when compared to low-dose AAV-FKRP alone. Together, our results support the potential benefits of combining ribitol with AAV gene therapy for treating FKRP-related muscular dystrophy. The fact that ribitol is a metabolite in nature and has already been tested in animal models and clinical trials in humans without severe side effects provides a safety profile for it to be trialed in combination with AAV gene therapy.
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Affiliation(s)
- Marcela P Cataldi
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Carolinas Medical Center, Atrium Health, Charlotte, NC 28203, USA.
| | - Charles H Vannoy
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Carolinas Medical Center, Atrium Health, Charlotte, NC 28203, USA
| | - Anthony Blaeser
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Carolinas Medical Center, Atrium Health, Charlotte, NC 28203, USA
| | - Jason D Tucker
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Carolinas Medical Center, Atrium Health, Charlotte, NC 28203, USA
| | - Victoria Leroy
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Carolinas Medical Center, Atrium Health, Charlotte, NC 28203, USA
| | - Raegan Rawls
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Carolinas Medical Center, Atrium Health, Charlotte, NC 28203, USA
| | - Jessalyn Killilee
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Carolinas Medical Center, Atrium Health, Charlotte, NC 28203, USA
| | - Molly C Holbrook
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Carolinas Medical Center, Atrium Health, Charlotte, NC 28203, USA
| | - Qi Long Lu
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Carolinas Medical Center, Atrium Health, Charlotte, NC 28203, USA.
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Unnikrishnan G, Polavarapu K, Bardhan M, Nashi S, Vengalil S, Preethish-Kumar V, Valasani RK, Huddar A, Nishadham V, Nandeesh BN, Nalini A. Phenotype Genotype Characterization of FKRP-related Muscular Dystrophy among Indian Patients. J Neuromuscul Dis 2023:JND221618. [PMID: 37154180 DOI: 10.3233/jnd-221618] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
BACKGROUND The phenotypic spectrum of Fukutin-related protein (FKRP) mutations is highly variable and comprises of limb girdle muscular dystrophy (LGMD) R9 (previously LGMD 2I) and FKRP related congenital muscular dystrophies. OBJECTIVE To identify the distinct genotype phenotype pattern in Indian patients with FKRP gene mutations. METHODS We retrospectively reviewed the case files of patients with muscular dystrophy having a genetically confirmed FKRP mutation. All patients had undergone genetic testing using next-generation sequencing. RESULTS Our patients included five males and four females presenting between 1.5 years and seven years of age (median age - 3 years). The initial symptom was a delayed acquisition of gross motor developmental milestones in seven patients and recurrent falls and poor sucking in one patient each. Two patients had a language delay, with both having abnormalities on the brain MRI. Macroglossia, scapular winging, and facial weakness were noted in one, three and four patients respectively. Calf muscle hypertrophy was seen in eight patients and ankle contractures in six. At the last follow-up, three patients had lost ambulation (median age - 7 years; range 6.5-9 years) and three patients had not attained independent ambulation. Creatine kinase levels ranged between 2793 and 32,396 U/L (mean 12,120 U/L). A common mutation - c.1343C>T was noted in 5 patients in our cohort. Additionally, four novel mutations were identified. Overall, six patients had an LGMD R9 phenotype, and three had a congenital muscular dystrophy phenotype. CONCLUSION Patients with FKRP mutations can have varied presentations. A Duchenne-like phenotype was the most commonly encountered pattern in our cohort, with c.1343C>T being the most common mutation.
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Affiliation(s)
| | - Kiran Polavarapu
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bangalore, India
| | - Mainak Bardhan
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bangalore, India
| | - Saraswati Nashi
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bangalore, India
| | - Seena Vengalil
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bangalore, India
| | | | - Ravi Kiran Valasani
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bangalore, India
| | - Akshata Huddar
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bangalore, India
| | - Vikas Nishadham
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bangalore, India
| | | | - Atchayaram Nalini
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bangalore, India
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Wu B, Drains M, Shah SN, Lu PJ, Leroy V, Killilee J, Rawls R, Tucker JD, Blaeser A, Lu QL. Ribitol dose-dependently enhances matriglycan expression and improves muscle function with prolonged life span in limb girdle muscular dystrophy 2I mouse model. PLoS One 2022; 17:e0278482. [PMID: 36454905 PMCID: PMC9714851 DOI: 10.1371/journal.pone.0278482] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 11/16/2022] [Indexed: 12/05/2022] Open
Abstract
Limb Girdle Muscular Dystrophy 2I (LGMDR9) is one of the most common LGMD characterized by defects in glycosylation of α-dystroglycan (matriglycan) resulting from mutations of Fukutin-related protein (FKRP). There is no effective therapy currently available. We recently demonstrated that ribitol supplement increases levels of matriglycan in cells in vitro and in FKRP-P448L (P448L) mutant mouse model through drinking water administration. To be clinically relevant, we have now conducted a dose-escalating efficacy study by gavage in P448L mutant mice. Six months of ribitol treatment daily significantly rescued functions of skeletal, respiratory, and cardiac muscles dose-dependently. This was associated with a dose dependent increase in matriglycan and improvement in muscle pathology with reductions in muscle degeneration, inflammatory infiltration and fibrosis. Importantly, ribitol significantly increased life span and muscle functions of the female animals receiving treatment from 10 months of age. The only observed side effect was gastrointestinal tract bloating with loose stool and this effect is also dose dependent. The results validate the mechanism that ribitol as a pre-substrate of glycosyltransferase is able to compensate for the decreased function of mutant FKRP with restoration of matriglycan expression and provide a guidance for future clinical trial design.
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Affiliation(s)
- Bo Wu
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Atrium Health Musculoskeletal Institute, Carolinas Medical Center, Charlotte, North Carolina, United States of America
- * E-mail: (BW); (QLL)
| | - Morgan Drains
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Atrium Health Musculoskeletal Institute, Carolinas Medical Center, Charlotte, North Carolina, United States of America
| | - Sapana N. Shah
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Atrium Health Musculoskeletal Institute, Carolinas Medical Center, Charlotte, North Carolina, United States of America
| | - Pei Juan Lu
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Atrium Health Musculoskeletal Institute, Carolinas Medical Center, Charlotte, North Carolina, United States of America
| | - Victoria Leroy
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Atrium Health Musculoskeletal Institute, Carolinas Medical Center, Charlotte, North Carolina, United States of America
| | - Jessalyn Killilee
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Atrium Health Musculoskeletal Institute, Carolinas Medical Center, Charlotte, North Carolina, United States of America
| | - Raegan Rawls
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Atrium Health Musculoskeletal Institute, Carolinas Medical Center, Charlotte, North Carolina, United States of America
| | - Jason D. Tucker
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Atrium Health Musculoskeletal Institute, Carolinas Medical Center, Charlotte, North Carolina, United States of America
| | - Anthony Blaeser
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Atrium Health Musculoskeletal Institute, Carolinas Medical Center, Charlotte, North Carolina, United States of America
| | - Qi Long Lu
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Atrium Health Musculoskeletal Institute, Carolinas Medical Center, Charlotte, North Carolina, United States of America
- * E-mail: (BW); (QLL)
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Kanagawa M. Dystroglycanopathy: From Elucidation of Molecular and Pathological Mechanisms to Development of Treatment Methods. Int J Mol Sci 2021; 22:ijms222313162. [PMID: 34884967 PMCID: PMC8658603 DOI: 10.3390/ijms222313162] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Revised: 12/02/2021] [Accepted: 12/03/2021] [Indexed: 01/13/2023] Open
Abstract
Dystroglycanopathy is a collective term referring to muscular dystrophies with abnormal glycosylation of dystroglycan. At least 18 causative genes of dystroglycanopathy have been identified, and its clinical symptoms are diverse, ranging from severe congenital to adult-onset limb-girdle types. Moreover, some cases are associated with symptoms involving the central nervous system. In the 2010s, the structure of sugar chains involved in the onset of dystroglycanopathy and the functions of its causative gene products began to be identified as if they were filling the missing pieces of a jigsaw puzzle. In parallel with these discoveries, various dystroglycanopathy model mice had been created, which led to the elucidation of its pathological mechanisms. Then, treatment strategies based on the molecular basis of glycosylation began to be proposed after the latter half of the 2010s. This review briefly explains the sugar chain structure of dystroglycan and the functions of the causative gene products of dystroglycanopathy, followed by introducing the pathological mechanisms involved as revealed from analyses of dystroglycanopathy model mice. Finally, potential therapeutic approaches based on the pathological mechanisms involved are discussed.
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Affiliation(s)
- Motoi Kanagawa
- Department of Cell Biology and Molecular Medicine, Graduate School of Medicine, Ehime University, 454 Shitsukawa, Toon 791-0295, Ehime, Japan
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7
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Lu QL. Revertant Phenomenon in DMD and LGMD2I and Its Therapeutic Implications: A Review of Study Under Mentorship of Terrence Partridge. J Neuromuscul Dis 2021; 8:S359-S367. [PMID: 34151854 PMCID: PMC8673541 DOI: 10.3233/jnd-210692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This review recollects my initial research focus on revertant fibers (expressing dystrophin in the background of frame-shifting mutation) in Duchenne muscular dystrophy (DMD) muscles in Professor Terrence Partridge’s Muscle Cell Biology Laboratory in MRC Clinical Research Science Center, Harmmersmith Hospital, London, UK. Our data indicated that revertant fibers are most likely resulted from epigenetic random events which skip exon(s) flanking the mutated exon, leading to the restoration of the reading frame. Some of these events establish themselves as relatively permanent skipping patterns, a mechanism similar to multiple transcript species established in various cell types. With this hypothesis, antisense oligonucleotide-mediated exon skipping is likely to have a great chance to achieve restoration of therapeutic levels of dystrophin in DMD muscles. This leads to our first reports of local and systemic efficacy of antisense oligonucleotide-mediated exon skipping for DMD treatment. The experience under Terry’s mentorship shaped my thinking and led me to explore another revertant feature in the dystroglycanopathy caused by mutations in the Fukutin Related Protein (FKRP) gene which functions as a glycosyltransferase. Mutant FKRPs retain partial function and produce a fraction of normal to no detectable levels of laminin-binding α-dystroglycan (matriglycan) in most of the muscle fibers. Reversion to near normal levels of matriglycan expression in muscles with FKRP mutations depends on muscle regeneration and in muscles of neonate mice, suggesting that changes in metabolism and gene expression could be sufficient to compensate for the reduced function of mutant FKRP genes even those associated with severe congenital muscular dystrophy (CMD). This is now supported by our successful demonstration that supply of FKRP mutant mice with ribitol, a precursor for substrate of FKRP, is sufficient to restore the levels of matriglycan with therapeutic significance. Our data overall suggest that rare events of reversion in muscular dystrophy, and likely other diseases could provide unique insight for mechanisms and therapeutic exploitation.
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Affiliation(s)
- Qi Long Lu
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Musculoskeletal Institute, Atrium Health, Charlotte, NC, USA
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8
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Brown SC, Fernandez-Fuente M, Muntoni F, Vissing J. Phenotypic Spectrum of α-Dystroglycanopathies Associated With the c.919T>a Variant in the FKRP Gene in Humans and Mice. J Neuropathol Exp Neurol 2021; 79:1257-1264. [PMID: 33051673 DOI: 10.1093/jnen/nlaa120] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Mutations in the fukutin-related protein gene, FKRP, are the most frequent single cause of α-dystroglycanopathy. Rare FKRP mutations are clinically not well characterized. Here, we review the phenotype associated with the rare c.919T>A mutation in FKRP in humans and mice. We describe clinical and paraclinical findings in 6 patients, 2 homozygous, and 4-compound heterozygous for c.919T>A, and compare findings with a mouse model we generated, which is homozygous for the same mutation. In patients, the mutation at the homozygous state is associated with a severe congenital muscular dystrophy phenotype invariably characterized by severe multisystem disease and early death. Compound heterozygous patients have a severe limb-girdle muscular dystrophy phenotype, loss of ambulation before age 20 and respiratory insufficiency. In contrast, mice homozygous for the same mutation show no symptoms or signs of muscle disease. Evidence therefore defines the FKRP c.919T>A as a very severe mutation in humans. The huge discrepancy between phenotypes in humans and mice suggests that differences in protein folding/processing exist between human and mouse Fkrp. This emphasizes the need for more detailed structural analyses of FKRP and shows the challenges of developing appropriate animal models of dystroglycanopathies that mimic the disease course in humans.
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Affiliation(s)
- Susan C Brown
- Department of Comparative Biomedical Sciences, Royal Veterinary College, London, UK
| | | | - Francesco Muntoni
- Dubowitz Neuromuscular Centre, UCL Great Ormond Street Institute of Child Health & Great Ormond Street Hospital, London, UK and National Institute for Health Research Great Ormond Street Hospital Biomedical Research Centre, UCL Great Ormond Street Institute of Child Health, London
| | - John Vissing
- Copenhagen Neuromuscular Center, Department of Neurology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
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Sasaki E, Hayashi Y, Kimura Y, Sashida S, Hamano N, Nirasawa K, Hamada K, Katagiri F, Kikkawa Y, Sakai T, Yoshida A, Kawada M, Hirashima SI, Miura T, Endo-Takahashi Y, Nomizu M, Negishi Y. Alpha-dystroglycan binding peptide A2G80-modified stealth liposomes as a muscle-targeting carrier for Duchenne muscular dystrophy. J Control Release 2021; 329:1037-1045. [PMID: 33080271 DOI: 10.1016/j.jconrel.2020.10.032] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Revised: 10/07/2020] [Accepted: 10/16/2020] [Indexed: 01/16/2023]
Abstract
Safe and efficient gene therapy for the treatment of Duchenne muscular dystrophy (DMD), a genetic disorder, is required. For this, the muscle-targeting delivery system of genes and nucleic acids is ideal. In this study, we focused on the A2G80 peptide, which has an affinity for α-dystroglycan expressed on muscle cell membranes, as a muscle targeted nanocarrier for DMD and developed A2G80-modified liposomes. We also prepared A2G80-modified liposomes coated with long- and short-chain PEG, called A2G80-LSP-Lip, to improve the blood circulation of liposomes using microfluidics. The liposomes had a particle size of approximately 80 nm. A2G80-LSP-Lip showed an affinity for the muscle tissue section of mice by overlay assay. When the liposomes were administered to DMD model mice (mdx mice) via the tail vein, A2G80-LSP-Lip accumulated efficiently in muscle tissue compared to control liposomes. These results suggest that A2G80-LSP-Lip can function as a muscle-targeting liposome for DMD via systemic administration, and may be a useful tool for DMD treatment.
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Affiliation(s)
- Eri Sasaki
- Department of Drug Delivery and Molecular Biopharmaceutics, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan
| | - Yoshihiro Hayashi
- Department of Drug Delivery and Molecular Biopharmaceutics, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan
| | - Yuka Kimura
- Department of Drug Delivery and Molecular Biopharmaceutics, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan
| | - Sanae Sashida
- Department of Drug Delivery and Molecular Biopharmaceutics, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan
| | - Nobuhito Hamano
- Department of Drug Delivery and Molecular Biopharmaceutics, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan
| | - Kei Nirasawa
- Department of Drug Delivery and Molecular Biopharmaceutics, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan
| | - Keisuke Hamada
- Department of Clinical Biochemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Tokyo 192-0392, Japan
| | - Fumihiko Katagiri
- Department of Clinical Biochemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Tokyo 192-0392, Japan
| | - Yamato Kikkawa
- Department of Clinical Biochemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Tokyo 192-0392, Japan
| | - Takaaki Sakai
- Department of Pharmaceutical Chemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan
| | - Akihiro Yoshida
- Department of Pharmaceutical Chemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan
| | - Masahiro Kawada
- Department of Pharmaceutical Chemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan
| | - Shin-Ichi Hirashima
- Department of Pharmaceutical Chemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan
| | - Tsuyoshi Miura
- Department of Pharmaceutical Chemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan
| | - Yoko Endo-Takahashi
- Department of Drug Delivery and Molecular Biopharmaceutics, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan
| | - Motoyoshi Nomizu
- Department of Clinical Biochemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Tokyo 192-0392, Japan
| | - Yoichi Negishi
- Department of Drug Delivery and Molecular Biopharmaceutics, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan.
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Ortiz-Cordero C, Azzag K, Perlingeiro RCR. Fukutin-Related Protein: From Pathology to Treatments. Trends Cell Biol 2020; 31:197-210. [PMID: 33272829 DOI: 10.1016/j.tcb.2020.11.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 11/02/2020] [Accepted: 11/04/2020] [Indexed: 12/27/2022]
Abstract
Fukutin-related protein (FKRP) is a glycosyltransferase involved in the functional glycosylation of α-dystroglycan (DG), a key component in the link between the cytoskeleton and the extracellular matrix (ECM). Mutations in FKRP lead to dystroglycanopathies with broad severity, including limb-girdle and congenital muscular dystrophy. Studies over the past 5 years have elucidated the function of FKRP, which has expanded the number of therapeutic opportunities for patients carrying FKRP mutations. These include small molecules, gene delivery, and cell therapy. Here we summarize recent findings on the function of FKRP and describe available models for studying diseases and testing therapeutics. Lastly, we highlight preclinical studies that hold potential for the treatment of FKRP-associated dystroglycanopathies.
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Affiliation(s)
- Carolina Ortiz-Cordero
- Lillehei Heart Institute, Department of Medicine, University of Minnesota, Minneapolis, MN, USA; Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN, USA
| | - Karim Azzag
- Lillehei Heart Institute, Department of Medicine, University of Minnesota, Minneapolis, MN, USA
| | - Rita C R Perlingeiro
- Lillehei Heart Institute, Department of Medicine, University of Minnesota, Minneapolis, MN, USA; Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN, USA; Stem Cell Institute, University of Minnesota, Minneapolis, MN, USA.
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11
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Vaubourg C, Gicquel E, Richard I, Lostal W, Bellec J. Minimal Consequences of CMAH and DBA/2 Backgrounds on a FKRP Deficient Model. J Neuromuscul Dis 2020; 8:785-793. [PMID: 32925084 DOI: 10.3233/jnd-200487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Muscular dystrophies (MD) are a large group of genetic diseases characterized by a progressive loss of muscle. The Latent TGFβ Binding Protein 4 (LTBP4) in the DBA/2 background and the Cytidine Monophosphate-sialic Acid Hydroxylase (CMAH) proteins were previously identified as genetic modifiers in severe MD. OBJECTIVE We investigated whether these modifiers could also influence a mild phenotype such as the one observed in a mouse model of Limb-Girdle MD2I (LGMD2I). METHODS The FKRPL276I mouse model was backcrossed onto the DBA/2 background, and in separate experiments the Cmah gene was inactivated in FKRPL276I mice by crossing with a Cmah-/- mouse and selecting the double-mutants. The mdx mouse was used as control for these two genome modifications. Consequences at the histological level as well as quantification of expression level by RT-qPCR of genes relevant for muscular dystrophy were then performed. RESULTS We observed minimal to no effect of the DBA/2 background on the mild FKRPL276I mouse phenotype, while this same background was previously shown to increase inflammation and fibrosis in the mdx mouse. Similarly, the Cmah-/- deletion had no observable effect on the FKRPL276I mouse phenotype whereas it was seen to increase features of regeneration in mdx mice. CONCLUSIONS These modifiers were not observed to impact the severity of the presentation of the mild FKRPL276I model. An interesting association of the CMAH modifier with the regeneration process in the mdx model was seen and sheds new light on the influence of this protein on the dystrophic phenotype.
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Affiliation(s)
- Camille Vaubourg
- Généthon, Evry, France.,Université Paris-Saclay, Univ Evry, Inserm, Généthon, Integrare research unit UMR_S951, 91000, Evry, France
| | - Evelyne Gicquel
- Généthon, Evry, France.,Université Paris-Saclay, Univ Evry, Inserm, Généthon, Integrare research unit UMR_S951, 91000, Evry, France
| | - Isabelle Richard
- Généthon, Evry, France.,Université Paris-Saclay, Univ Evry, Inserm, Généthon, Integrare research unit UMR_S951, 91000, Evry, France
| | - William Lostal
- Généthon, Evry, France.,Université Paris-Saclay, Univ Evry, Inserm, Généthon, Integrare research unit UMR_S951, 91000, Evry, France
| | - Jessica Bellec
- Généthon, Evry, France.,Université Paris-Saclay, Univ Evry, Inserm, Généthon, Integrare research unit UMR_S951, 91000, Evry, France
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12
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Cataldi MP, Blaeser A, Lu P, Leroy V, Lu QL. ISPD Overexpression Enhances Ribitol-Induced Glycosylation of α-Dystroglycan in Dystrophic FKRP Mutant Mice. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2019; 17:271-280. [PMID: 31988979 PMCID: PMC6970132 DOI: 10.1016/j.omtm.2019.12.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 12/03/2019] [Indexed: 12/11/2022]
Abstract
Dystroglycanopathy, a subgroup of muscular dystrophies, is characterized by hypoglycosylation of α-dystroglycan (α-DG), which reduces its laminin-binding activity to extracellular matrix proteins, causing progressive loss of muscle integrity and function. Mutations in the fukutin-related protein (FKRP) gene are the most common causes of dystroglycanopathy. FKRP transfers ribitol-5-phosphate to the O-mannosyl glycan on α-DG from substrate cytidine diphosphate (CDP)-ribitol, which is synthesized by isoprenoid synthase domain-containing protein (ISPD). We previously reported that oral administration of ribitol restores therapeutic levels of functional glycosylation of α-DG (F-α-DG) in a FKRP mutant mouse model. Here we examine the contribution of adeno-associated virus (AAV)-mediated overexpression of ISPD to the levels of CDP-ribitol and F-α-DG with and without ribitol supplementation in the disease model. ISPD overexpression alone and in combination with ribitol improves dystrophic phenotype. Furthermore, the combined approach of ribitol and ISPD acts synergistically, increasing F-α-DG up to 40% of normal levels in cardiac muscle and more than 20% in limb and diaphragm. The results suggest that low levels of substrate limit production of CDP-ribitol, and endogenous ISPD also becomes a limiting factor in the presence of a supraphysiological concentration of ribitol. Our data support further investigation of the regulatory pathway for enhancing efficacy of ribitol supplement to FKRP-related dystroglycanopathy.
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Affiliation(s)
- Marcela P Cataldi
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Carolinas Medical Center, Atrium Health, Charlotte, NC 28203, USA
| | - Anthony Blaeser
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Carolinas Medical Center, Atrium Health, Charlotte, NC 28203, USA
| | - Peijuan Lu
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Carolinas Medical Center, Atrium Health, Charlotte, NC 28203, USA
| | - Victoria Leroy
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Carolinas Medical Center, Atrium Health, Charlotte, NC 28203, USA
| | - Qi Long Lu
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Carolinas Medical Center, Atrium Health, Charlotte, NC 28203, USA
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13
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Vannoy CH, Leroy V, Broniowska K, Lu QL. Metabolomics Analysis of Skeletal Muscles from FKRP-Deficient Mice Indicates Improvement After Gene Replacement Therapy. Sci Rep 2019; 9:10070. [PMID: 31296900 PMCID: PMC6624266 DOI: 10.1038/s41598-019-46431-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 06/28/2019] [Indexed: 12/31/2022] Open
Abstract
Muscular dystrophy-dystroglycanopathies comprise a heterogeneous and complex group of disorders caused by loss-of-function mutations in a multitude of genes that disrupt the glycobiology of α-dystroglycan, thereby affecting its ability to function as a receptor for extracellular matrix proteins. Of the various genes involved, FKRP codes for a protein that plays a critical role in the maturation of a novel glycan found only on α-dystroglycan. Yet despite knowing the genetic cause of FKRP-related dystroglycanopathies, the molecular pathogenesis of disease and metabolic response to therapeutic intervention has not been fully elucidated. To address these challenges, we utilized mass spectrometry-based metabolomics to generate comprehensive metabolite profiles of skeletal muscle across diseased, treated, and normal states. Notably, FKRP-deficient mice elicit diverse metabolic abnormalities in biomarkers of extracellular matrix remodeling and/or aging, pentoses/pentitols, glycolytic intermediates, and lipid metabolism. More importantly, the restoration of FKRP protein activity following AAV-mediated gene therapy induced a substantial correction of these metabolic impairments. While interconnections of the affected molecular mechanisms remain unclear, our datasets support the notion that global metabolic profiling can be valuable for determining the involvement of previously unsuspected regulatory or pathological pathways as well as identifying potential targets for drug discovery and diagnostics.
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Affiliation(s)
- Charles Harvey Vannoy
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Carolinas Medical Center, Atrium Health, Charlotte, NC, 28203, USA.
| | - Victoria Leroy
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Carolinas Medical Center, Atrium Health, Charlotte, NC, 28203, USA
| | | | - Qi Long Lu
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Carolinas Medical Center, Atrium Health, Charlotte, NC, 28203, USA.
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14
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Nickolls AR, Bönnemann CG. The roles of dystroglycan in the nervous system: insights from animal models of muscular dystrophy. Dis Model Mech 2018; 11:11/12/dmm035931. [PMID: 30578246 PMCID: PMC6307911 DOI: 10.1242/dmm.035931] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Dystroglycan is a cell membrane protein that binds to the extracellular matrix in a variety of mammalian tissues. The α-subunit of dystroglycan (αDG) is heavily glycosylated, including a special O-mannosyl glycoepitope, relying upon this unique glycosylation to bind its matrix ligands. A distinct group of muscular dystrophies results from specific hypoglycosylation of αDG, and they are frequently associated with central nervous system involvement, ranging from profound brain malformation to intellectual disability without evident morphological defects. There is an expanding literature addressing the function of αDG in the nervous system, with recent reports demonstrating important roles in brain development and in the maintenance of neuronal synapses. Much of these data are derived from an increasingly rich array of experimental animal models. This Review aims to synthesize the information from such diverse models, formulating an up-to-date understanding about the various functions of αDG in neurons and glia of the central and peripheral nervous systems. Where possible, we integrate these data with our knowledge of the human disorders to promote translation from basic mechanistic findings to clinical therapies that take the neural phenotypes into account. Summary: Dystroglycan is a ubiquitous matrix receptor linked to brain and muscle disease. Unraveling the functions of this protein will inform basic and translational research on neural development and muscular dystrophies.
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Affiliation(s)
- Alec R Nickolls
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA.,Department of Neuroscience, Brown University, Providence, RI 02912, USA
| | - Carsten G Bönnemann
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
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15
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Vannoy CH, Leroy V, Lu QL. Dose-Dependent Effects of FKRP Gene-Replacement Therapy on Functional Rescue and Longevity in Dystrophic Mice. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2018; 11:106-120. [PMID: 30417025 PMCID: PMC6222079 DOI: 10.1016/j.omtm.2018.10.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 10/08/2018] [Indexed: 12/31/2022]
Abstract
Muscular dystrophy-dystroglycanopathies (MDDGs) resulting from fukutin-related protein (FKRP) gene mutations are rare disorders that result in a wide spectrum of clinical severity based on the age of onset, the degree of myogenic atrophy, and/or neurologic involvement. There is no cure for any of the FKRP-related disorders, and few options are available for symptom management. Herein, we examine the longitudinal effects of a dose-escalation study to evaluate the safety and therapeutic potential of FKRP gene-replacement therapy in a p.P448L (FKRPP448L) mouse model of MDDG. A recombinant adeno-associated virus (AAV) serotype 9 vector expressing human FKRP (AAV9-FKRP) was systemically administered to FKRPP448L mice at 5 weeks of age, when early onset of the disease is evidenced. A comprehensive analysis of protein and gene expression, histopathology, skeletal muscle function, and cardiorespiratory function was performed over short (9-week) and/or long-term (52-week) study periods. Additional studies assessed the impact of FKRP gene-replacement therapy on lifespan at an advanced stage of disease progression. Results indicate that treatment intervention can restore the biochemical defects in a dose-dependent manner, with potential for improvement in the trajectory of disease progression and extension of the expected lifespan. This study supports the initiation of early-stage clinical trials for FKRP-related disorders.
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Affiliation(s)
- Charles Harvey Vannoy
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Carolinas Medical Center, Atrium Health, Charlotte, NC 28203, USA
- Corresponding author: Charles Harvey Vannoy, McColl-Lockwood Laboratory for Muscular Dystrophy Research, Carolinas Medical Center, Atrium Health, Charlotte, NC 28203, USA.
| | - Victoria Leroy
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Carolinas Medical Center, Atrium Health, Charlotte, NC 28203, USA
| | - Qi Long Lu
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Carolinas Medical Center, Atrium Health, Charlotte, NC 28203, USA
- Corresponding author: Qi Long Lu, McColl-Lockwood Laboratory for Muscular Dystrophy Research, Carolinas Medical Center, Atrium Health, Charlotte, NC 28203, USA.
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16
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Serafini PR, Feyder MJ, Hightower RM, Garcia-Perez D, Vieira NM, Lek A, Gibbs DE, Moukha-Chafiq O, Augelli-Szafran CE, Kawahara G, Widrick JJ, Kunkel LM, Alexander MS. A limb-girdle muscular dystrophy 2I model of muscular dystrophy identifies corrective drug compounds for dystroglycanopathies. JCI Insight 2018; 3:120493. [PMID: 30232282 DOI: 10.1172/jci.insight.120493] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 08/07/2018] [Indexed: 01/31/2023] Open
Abstract
Zebrafish are a powerful tool for studying muscle function owing to their high numbers of offspring, low maintenance costs, evolutionarily conserved muscle functions, and the ability to rapidly take up small molecular compounds during early larval stages. Fukutin-related protein (FKRP) is a putative protein glycosyltransferase that functions in the Golgi apparatus to modify sugar chain molecules of newly translated proteins. Patients with mutations in the FKRP gene can have a wide spectrum of clinical symptoms with varying muscle, eye, and brain pathologies depending on the location of the mutation in the FKRP protein. Patients with a common L276I FKRP mutation have mild adult-onset muscle degeneration known as limb-girdle muscular dystrophy 2I (LGMD2I), whereas patients with more C-terminal pathogenic mutations develop the severe Walker-Warburg syndrome (WWS)/muscle-eye-brain (MEB) disease. We generated fkrp-mutant zebrafish that phenocopy WWS/MEB pathologies including severe muscle breakdowns, head malformations, and early lethality. We have also generated a milder LGMD2I-model zebrafish via overexpression of a heat shock-inducible human FKRP (L276I) transgene that shows milder muscle pathology. Screening of an FDA-approved drug compound library in the LGMD2I zebrafish revealed a strong propensity towards steroids, antibacterials, and calcium regulators in ameliorating FKRP-dependent pathologies. Together, these studies demonstrate the utility of the zebrafish to both study human-specific FKRP mutations and perform compound library screenings for corrective drug compounds to treat muscular dystrophies.
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Affiliation(s)
- Peter R Serafini
- Division of Genetics and Genomics at Boston Children's Hospital, Boston, Massachusetts, USA
| | - Michael J Feyder
- Division of Genetics and Genomics at Boston Children's Hospital, Boston, Massachusetts, USA
| | - Rylie M Hightower
- Department of Pediatrics, Division of Neurology at the University of Alabama at Birmingham and Children's of Alabama, Birmingham, Alabama, USA.,UAB Center for Exercise Medicine at the University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Daniela Garcia-Perez
- Department of Pediatrics, Division of Neurology at the University of Alabama at Birmingham and Children's of Alabama, Birmingham, Alabama, USA
| | - Natássia M Vieira
- Division of Genetics and Genomics at Boston Children's Hospital, Boston, Massachusetts, USA
| | - Angela Lek
- Division of Genetics and Genomics at Boston Children's Hospital, Boston, Massachusetts, USA
| | - Devin E Gibbs
- Division of Genetics and Genomics at Boston Children's Hospital, Boston, Massachusetts, USA
| | | | | | - Genri Kawahara
- Department of Pathophysiology, Tokyo Medical University, Tokyo, Japan
| | - Jeffrey J Widrick
- Division of Genetics and Genomics at Boston Children's Hospital, Boston, Massachusetts, USA
| | - Louis M Kunkel
- Division of Genetics and Genomics at Boston Children's Hospital, Boston, Massachusetts, USA.,Harvard Stem Cell Institute, Cambridge, Massachusetts, USA.,The Manton Center for Orphan Disease Research at Boston Children's Hospital, Boston, Massachusetts, USA
| | - Matthew S Alexander
- Department of Pediatrics, Division of Neurology at the University of Alabama at Birmingham and Children's of Alabama, Birmingham, Alabama, USA.,UAB Center for Exercise Medicine at the University of Alabama at Birmingham, Birmingham, Alabama, USA.,Department of Genetics at the University of Alabama at Birmingham, Birmingham, Alabama, USA
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17
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Cataldi MP, Lu P, Blaeser A, Lu QL. Ribitol restores functionally glycosylated α-dystroglycan and improves muscle function in dystrophic FKRP-mutant mice. Nat Commun 2018; 9:3448. [PMID: 30150693 PMCID: PMC6110760 DOI: 10.1038/s41467-018-05990-z] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2017] [Accepted: 08/09/2018] [Indexed: 02/07/2023] Open
Abstract
O-mannosylated α-dystroglycan (α-DG) serves as receptors for cell-cell and cell-extracellular matrix adhesion and signaling. Hypoglycosylation of α-DG is involved in cancer progression and underlies dystroglycanopathy with aberrant neuronal development. Here we report that ribitol, a pentose alcohol with previously unknown function in mammalian cells, partially restores functional O-mannosylation of α-DG (F-α-DG) in the dystroglycanopathy model containing a P448L mutation in fukutin-related protein (FKRP) gene, which is clinically associated with severe congenital muscular dystrophy. Oral administration of ribitol increases levels of ribitol-5-phosphate and CDP-ribitol and restores therapeutic levels of F-α-DG in skeletal and cardiac muscles. Furthermore, ribitol, given before and after the onset of disease phenotype, reduces skeletal muscle pathology, significantly decreases cardiac fibrosis and improves skeletal and respiratory functions in the FKRP mutant mice. Ribitol treatment presents a new class, low risk, and easy to administer experimental therapy to restore F-α-DG in FKRP-related muscular dystrophy.
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Affiliation(s)
- Marcela P Cataldi
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Carolinas Medical Center, Carolinas Healthcare System, Charlotte, NC, 28203, USA
| | - Peijuan Lu
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Carolinas Medical Center, Carolinas Healthcare System, Charlotte, NC, 28203, USA
| | - Anthony Blaeser
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Carolinas Medical Center, Carolinas Healthcare System, Charlotte, NC, 28203, USA
| | - Qi Long Lu
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Carolinas Medical Center, Carolinas Healthcare System, Charlotte, NC, 28203, USA.
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18
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Yu Q, Morales M, Li N, Fritz AG, Ruobing R, Blaeser A, Francois E, Lu QL, Nagaraju K, Spurney CF. Skeletal, cardiac, and respiratory muscle function and histopathology in the P448Lneo- mouse model of FKRP-deficient muscular dystrophy. Skelet Muscle 2018; 8:13. [PMID: 29625576 PMCID: PMC5889611 DOI: 10.1186/s13395-018-0158-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Accepted: 03/20/2018] [Indexed: 01/17/2023] Open
Abstract
BACKGROUND Fukutin-related protein (FKRP) mutations are the most common cause of dystroglycanopathies known to cause both limb girdle and congenital muscular dystrophy. The P448Lneo- mouse model has a knock-in mutation in the FKRP gene and develops skeletal, respiratory, and cardiac muscle disease. METHODS We studied the natural history of the P448Lneo- mouse model over 9 months and the effects of twice weekly treadmill running. Forelimb and hindlimb grip strength (Columbus Instruments) and overall activity (Omnitech Electronics) assessed skeletal muscle function. Echocardiography was performed using VisualSonics Vevo 770 (FujiFilm VisualSonics). Plethysmography was performed using whole body system (ADInstruments). Histological evaluations included quantification of inflammation, fibrosis, central nucleation, and fiber size variation. RESULTS P448Lneo- mice had significantly increased normalized tissue weights compared to controls at 9 months of age for the heart, gastrocnemius, soleus, tibialis anterior, quadriceps, and triceps. There were no significant differences seen in forelimb or hindlimb grip strength or activity monitoring in P448Lneo- mice with or without exercise compared to controls. Skeletal muscles demonstrated increased inflammation, fibrosis, central nucleation, and variation in fiber size compared to controls (p < 0.05) and worsened with exercise. Plethysmography showed significant differences in respiratory rates and decreased tidal and minute volumes in P448Lneo- mice (p < 0.01). There was increased fibrosis in the diaphragm compared to controls (p < 0.01). Echocardiography demonstrated decreased systolic function in 9-month-old mutant mice (p < 0.01). There was increased myocardial wall thickness and mass (p < 0.001) with increased fibrosis in 9-month-old P448Lneo- mice compared to controls (p < 0.05). mRNA expression for natriuretic peptide type A (Nppa) was significantly increased in P448Lneo- mice compared to controls at 6 months (p < 0.05) and for natriuretic peptide type B (Nppb) at 6 and 9 months of age (p < 0.05). CONCLUSIONS FKRP-deficient P448Lneo- mice demonstrate significant deficits in cardiac and respiratory functions compared to control mice, and this is associated with increased inflammation and fibrosis. This study provides new functional outcome measures for preclinical trials of FKRP-related muscular dystrophies.
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Affiliation(s)
- Qing Yu
- Center for Genetic Medicine Research, Children's Research Institute, Children's National Health System, Washington, DC, USA
| | - Melissa Morales
- School of Pharmacy and Pharmaceutical Sciences, Binghamton University, State University of New York, Binghamton, NY, USA
| | - Ning Li
- School of Pharmacy and Pharmaceutical Sciences, Binghamton University, State University of New York, Binghamton, NY, USA
| | - Alexander G Fritz
- School of Pharmacy and Pharmaceutical Sciences, Binghamton University, State University of New York, Binghamton, NY, USA
| | - Ren Ruobing
- Department of Oncology, Ruijing Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Anthony Blaeser
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Department of Neurology, Carolinas Healthcare System, Charlotte, NC, USA
| | - Ershia Francois
- Center for Genetic Medicine Research, Children's Research Institute, Children's National Health System, Washington, DC, USA
| | - Qi-Long Lu
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Department of Neurology, Carolinas Healthcare System, Charlotte, NC, USA
| | - Kanneboyina Nagaraju
- School of Pharmacy and Pharmaceutical Sciences, Binghamton University, State University of New York, Binghamton, NY, USA
| | - Christopher F Spurney
- Children's National Heart Institute, Center for Genetic Medicine Research, Children's National Health System, Washington, DC, USA.
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19
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Genetics and mechanisms leading to human cortical malformations. Semin Cell Dev Biol 2018; 76:33-75. [DOI: 10.1016/j.semcdb.2017.09.031] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 09/21/2017] [Accepted: 09/21/2017] [Indexed: 02/06/2023]
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20
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Tucker JD, Lu PJ, Xiao X, Lu QL. Overexpression of Mutant FKRP Restores Functional Glycosylation and Improves Dystrophic Phenotype in FKRP Mutant Mice. MOLECULAR THERAPY-NUCLEIC ACIDS 2018; 11:216-227. [PMID: 29858056 PMCID: PMC5992437 DOI: 10.1016/j.omtn.2018.02.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 02/20/2018] [Accepted: 02/23/2018] [Indexed: 11/17/2022]
Abstract
Autosomal recessive homozygous or compound heterozygous mutations in FKRP result in forms of muscular dystrophy-dystroglycanopathy varying in age of onset, clinical presentation, and disease progression, ranging from the severe Walker-Warburg, type A,5 (MDDGA5), muscle-eye-brain (MDDGB5) with or without cognitive deficit, to limb-girdle type 2I (MDDGC5). Phenotypic variation indicates degrees of functionality of individual FKRP mutation, which has been supported by the presence of residual expression of functionally glycosylated α-dystroglycan (DG) in muscles of both animal models and patients. However, direct evidence showing enhancement in glycosylation of α-DG by mutant FKRP is lacking. Using AAV9-mediated overexpression of mutant human FKRP bearing the P448L mutation (mhFKRP-P448L) associated with severe congenital muscular dystrophy (CMD), we demonstrate the restoration of functional glycosylation of α-DG and reduction in markers of disease progression. Expression of mhFKRP-P448L also corrects dystrophic phenotypes in the models of L276I mutation with mild disease phenotype and causes no obvious histological or biomarker alteration in C57BL/6 normal mice. Our results confirm the existing function of mutant FKRP. The results also suggest that mutant FKRP could be an alternative approach for potential gene therapy should normal FKRP gene products be immunogenic.
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Affiliation(s)
- Jason D Tucker
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, James G. Cannon Research Center, Carolinas Medical Center, Charlotte, NC 28203, USA
| | - Pei J Lu
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, James G. Cannon Research Center, Carolinas Medical Center, Charlotte, NC 28203, USA
| | - Xiao Xiao
- Division of Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Qi L Lu
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, James G. Cannon Research Center, Carolinas Medical Center, Charlotte, NC 28203, USA.
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21
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Blaeser A, Awano H, Lu P, Lu QL. Distinct expression of functionally glycosylated alpha-dystroglycan in muscle and non-muscle tissues of FKRP mutant mice. PLoS One 2018; 13:e0191016. [PMID: 29320543 PMCID: PMC5761899 DOI: 10.1371/journal.pone.0191016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Accepted: 12/27/2017] [Indexed: 01/06/2023] Open
Abstract
The glycosylation of alpha-dystroglycan (α-DG) is crucial in maintaining muscle cell membrane integrity. Dystroglycanopathies are identified by the loss of this glycosylation leading to a breakdown of muscle cell membrane integrity and eventual degeneration. However, a small portion of fibers expressing functionally glycosylated α-DG (F-α-DG) (revertant fibers, RF) have been identified. These fibers are generally small in size, centrally nucleated and linked to regenerating fibers. Examination of different muscles have shown various levels of RFs but it is unclear the extent of which they are present. Here we do a body-wide examination of muscles from the FKRP-P448L mutant mouse for the prevalence of RFs. We have identified great variation in the distribution of RF in different muscles and tissues. Triceps shows a large increase in RFs and together with centrally nucleated fibers whereas the pectoralis shows a reduction in revertant but increase in centrally nucleated fibers from 6 weeks to 6 months of age. We have also identified that the sciatic nerve with near normal levels of F-α-DG in the P448Lneo- mouse with reduced levels in the P448Lneo+ and absent in LARGEmyd. The salivary gland of LARGEmyd mice expresses high levels of F-α-DG. Interestingly the same glands in the P448Lneo-and to a lesser degree in P448Lneo+ also maintain considerable amount of F-α-DG, indicating the non-proliferating epithelial cells have a molecular setting permitting glycosylation.
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Affiliation(s)
- Anthony Blaeser
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Carolinas HealthCare System, Charlotte, North Carolina, United States of America
- * E-mail: (QL); (AB)
| | - Hiroyuki Awano
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Carolinas HealthCare System, Charlotte, North Carolina, United States of America
| | - Pei Lu
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Carolinas HealthCare System, Charlotte, North Carolina, United States of America
| | - Qi-Long Lu
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Carolinas HealthCare System, Charlotte, North Carolina, United States of America
- * E-mail: (QL); (AB)
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22
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Krebs MP, Collin GB, Hicks WL, Yu M, Charette JR, Shi LY, Wang J, Naggert JK, Peachey NS, Nishina PM. Mouse models of human ocular disease for translational research. PLoS One 2017; 12:e0183837. [PMID: 28859131 PMCID: PMC5578669 DOI: 10.1371/journal.pone.0183837] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Accepted: 08/12/2017] [Indexed: 01/24/2023] Open
Abstract
Mouse models provide a valuable tool for exploring pathogenic mechanisms underlying inherited human disease. Here, we describe seven mouse models identified through the Translational Vision Research Models (TVRM) program, each carrying a new allele of a gene previously linked to retinal developmental and/or degenerative disease. The mutations include four alleles of three genes linked to human nonsyndromic ocular diseases (Aipl1tvrm119, Aipl1tvrm127, Rpgrip1tvrm111, RhoTvrm334) and three alleles of genes associated with human syndromic diseases that exhibit ocular phentoypes (Alms1tvrm102, Clcn2nmf289, Fkrptvrm53). Phenotypic characterization of each model is provided in the context of existing literature, in some cases refining our current understanding of specific disease attributes. These murine models, on fixed genetic backgrounds, are available for distribution upon request and may be useful for understanding the function of the gene in the retina, the pathological mechanisms induced by its disruption, and for testing experimental approaches to treat the corresponding human ocular diseases.
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Affiliation(s)
- Mark P. Krebs
- The Jackson Laboratory, Bar Harbor, Maine, United States of America
| | - Gayle B. Collin
- The Jackson Laboratory, Bar Harbor, Maine, United States of America
| | - Wanda L. Hicks
- The Jackson Laboratory, Bar Harbor, Maine, United States of America
| | - Minzhong Yu
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, Ohio, United States of America
- Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, Ohio, United States of America
| | | | - Lan Ying Shi
- The Jackson Laboratory, Bar Harbor, Maine, United States of America
| | - Jieping Wang
- The Jackson Laboratory, Bar Harbor, Maine, United States of America
| | | | - Neal S. Peachey
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, Ohio, United States of America
- Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, Ohio, United States of America
- Research Service, Louis Stokes Cleveland VA Medical Center, Cleveland, Ohio, United States of America
| | - Patsy M. Nishina
- The Jackson Laboratory, Bar Harbor, Maine, United States of America
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23
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Vannoy CH, Xiao W, Lu P, Xiao X, Lu QL. Efficacy of Gene Therapy Is Dependent on Disease Progression in Dystrophic Mice with Mutations in the FKRP Gene. Mol Ther Methods Clin Dev 2017; 5:31-42. [PMID: 28480302 PMCID: PMC5415313 DOI: 10.1016/j.omtm.2017.02.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Accepted: 02/20/2017] [Indexed: 01/17/2023]
Abstract
Loss-of-function mutations in the Fukutin-related protein (FKRP) gene cause limb-girdle muscular dystrophy type 2I (LGMD2I) and other forms of congenital muscular dystrophy-dystroglycanopathy that are associated with glycosylation defects in the α-dystroglycan (α-DG) protein. Systemic administration of a single dose of recombinant adeno-associated virus serotype 9 (AAV9) vector expressing human FKRP to a mouse model of LGMD2I at various stages of disease progression was evaluated. The results demonstrate rescue of functional glycosylation of α-DG and muscle function, along with improvements in muscle structure at all disease stages versus age-matched untreated cohorts. Nevertheless, mice treated in the latter stages of disease progression revealed a decrease in beneficial effects of the treatment. The results provide a proof of concept for future clinical trials in patients with FKRP-related muscular dystrophy and demonstrate that AAV-mediated gene therapy can potentially benefit patients at all stages of disease progression, but earlier intervention would be highly preferred.
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Affiliation(s)
- Charles Harvey Vannoy
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Carolinas Medical Center, Carolinas Healthcare System, Charlotte, NC 28203, USA
| | - Will Xiao
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Carolinas Medical Center, Carolinas Healthcare System, Charlotte, NC 28203, USA
| | - Peijuan Lu
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Carolinas Medical Center, Carolinas Healthcare System, Charlotte, NC 28203, USA
| | - Xiao Xiao
- Division of Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Qi Long Lu
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Carolinas Medical Center, Carolinas Healthcare System, Charlotte, NC 28203, USA
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24
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Thomas PJ, Xu R, Martin PT. B4GALNT2 (GALGT2) Gene Therapy Reduces Skeletal Muscle Pathology in the FKRP P448L Mouse Model of Limb Girdle Muscular Dystrophy 2I. THE AMERICAN JOURNAL OF PATHOLOGY 2017; 186:2429-48. [PMID: 27561302 DOI: 10.1016/j.ajpath.2016.05.021] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Revised: 04/19/2016] [Accepted: 05/06/2016] [Indexed: 12/22/2022]
Abstract
Overexpression of B4GALNT2 (previously GALGT2) inhibits the development of muscle pathology in mouse models of Duchenne muscular dystrophy, congenital muscular dystrophy 1A, and limb girdle muscular dystrophy 2D. In these models, muscle GALGT2 overexpression induces the glycosylation of α dystroglycan with the cytotoxic T cell glycan and increases the overexpression of dystrophin and laminin α2 surrogates known to inhibit disease. Here, we show that GALGT2 gene therapy significantly reduces muscle pathology in FKRP P448Lneo(-) mice, a model for limb girdle muscular dystrophy 2I. rAAVrh74.MCK.GALGT2-treated FKRP P448Lneo(-) muscles showed reduced levels of centrally nucleated myofibers, reduced variance, increased size of myofiber diameters, reduced myofiber immunoglobulin G uptake, and reduced muscle wasting at 3 and 6 months after treatment. GALGT2 overexpression in FKRP P448Lneo(-) muscles did not cause substantial glycosylation of α dystroglycan with the cytotoxic T cell glycan or increased expression of dystrophin and laminin α2 surrogates in mature skeletal myofibers, but it increased the number of embryonic myosin-positive regenerating myofibers. These data demonstrate that GALGT2 overexpression can reduce the extent of muscle pathology in FKRP mutant muscles, but that it may do so via a mechanism that differs from its ability to induce surrogate gene expression.
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Affiliation(s)
- Paul J Thomas
- Center for Gene Therapy, The Research Institute at Nationwide Children's Hospital, Columbus, Ohio
| | - Rui Xu
- Center for Gene Therapy, The Research Institute at Nationwide Children's Hospital, Columbus, Ohio
| | - Paul T Martin
- Center for Gene Therapy, The Research Institute at Nationwide Children's Hospital, Columbus, Ohio; Department of Pediatrics, The Research Institute at Nationwide Children's Hospital, Columbus, Ohio.
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25
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Vannoy CH, Zhou H, Qiao C, Xiao X, Bang AG, Lu QL. Adeno-Associated Virus-Mediated Mini-Agrin Delivery Is Unable to Rescue Disease Phenotype in a Mouse Model of Limb Girdle Muscular Dystrophy Type 2I. THE AMERICAN JOURNAL OF PATHOLOGY 2017; 187:431-440. [PMID: 28107841 DOI: 10.1016/j.ajpath.2016.09.024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Revised: 09/22/2016] [Accepted: 09/27/2016] [Indexed: 11/19/2022]
Abstract
Agrin is a basement membrane-specific proteoglycan that can regulate orientation of cytoskeleton proteins and improve function of dystrophic skeletal muscle. In skeletal muscle, agrin binds with high affinity to laminin(s) and α-dystroglycan (α-DG), an integral part of the dystrophin-glycoprotein complex. Miniaturized forms of agrin (mAgrin) have been shown to ameliorate disease pathology in a laminin-α2 knockout mouse model of muscular dystrophy, acting as a link between α-DG and laminin(s). Here, we test whether mAgrin might also improve pathologies associated with FKRP-related dystroglycanopathies, another form of muscular dystrophy characterized by weak interactions between muscle and basement membranes. We demonstrate in vitro that mAgrin enhances laminin binding to primary myoblasts and fibroblasts from an FKRP mutant mouse model and that this enhancement is abrogated when mAgrin is in molar excess relative to laminin. However, in vivo delivery of mAgrin via adeno-associated virus (AAV) into FKRP mutant mice was unable to improve dystrophic phenotypes, both histologically and functionally. These results likely reflect insufficient binding of mAgrin to hypoglycosylated α-DG on muscle fibers and possibly abrogation of binding from molar excess of overexpressed AAV-delivered mAgrin. Further exploration of mAgrin modification is necessary to strengthen its binding to other membrane components, including hypoglycosylated α-DG, for potential therapeutic applications.
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Affiliation(s)
- Charles H Vannoy
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Carolinas Medical Center, Carolinas Healthcare System, Charlotte, North Carolina
| | - Haowen Zhou
- Conrad Prebys Center for Chemical Genomics, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California
| | - Chunping Qiao
- Division of Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Xiao Xiao
- Division of Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Anne G Bang
- Conrad Prebys Center for Chemical Genomics, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California.
| | - Qi L Lu
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Carolinas Medical Center, Carolinas Healthcare System, Charlotte, North Carolina.
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26
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Keramaris E, Lu PJ, Tucker J, Lu QL. Expression of glycosylated α-dystroglycan in newborn skeletal and cardiac muscles of fukutin related protein (FKRP) mutant mice. Muscle Nerve 2016; 55:582-590. [DOI: 10.1002/mus.25378] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 08/05/2016] [Accepted: 08/10/2016] [Indexed: 12/27/2022]
Affiliation(s)
- Elizabeth Keramaris
- McColl-Lockwood Laboratory for Muscular Dystrophy Research; Cannon Research Center, Carolinas Medical Center; 1542 Garden Terrace Charlotte North Carolina 28203 USA
| | - Pei J. Lu
- McColl-Lockwood Laboratory for Muscular Dystrophy Research; Cannon Research Center, Carolinas Medical Center; 1542 Garden Terrace Charlotte North Carolina 28203 USA
| | - Jason Tucker
- McColl-Lockwood Laboratory for Muscular Dystrophy Research; Cannon Research Center, Carolinas Medical Center; 1542 Garden Terrace Charlotte North Carolina 28203 USA
| | - Qi L. Lu
- McColl-Lockwood Laboratory for Muscular Dystrophy Research; Cannon Research Center, Carolinas Medical Center; 1542 Garden Terrace Charlotte North Carolina 28203 USA
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27
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Blaeser A, Awano H, Wu B, Lu QL. Progressive Dystrophic Pathology in Diaphragm and Impairment of Cardiac Function in FKRP P448L Mutant Mice. PLoS One 2016; 11:e0164187. [PMID: 27711214 PMCID: PMC5053477 DOI: 10.1371/journal.pone.0164187] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Accepted: 09/21/2016] [Indexed: 01/22/2023] Open
Abstract
Mutations in the gene for fukutin-related protein represent a subset of muscular dystrophies known as dystroglycanopathies characterized by loss of functionally-glycosylated-alpha-dystroglycan and a wide range of dystrophic phenotypes. Mice generated by our lab containing the P448L mutation in the fukutin-related protein gene demonstrate the dystrophic phenotype similar to that of LGMD2I. Here we examined the morphology of the heart and diaphragm, focusing on pathology of diaphragm and cardiac function of the mutant mice for up to 12 months. Both diaphragm and heart lack clear expression of functionally-glycosylated-alpha-dystroglycan throughout the observed period. The diaphragm undergoes progressive deterioration in histology with increasing amount of centranucleation and inflammation. Large areas of mononuclear cell infiltration and fibrosis of up to 60% of tissue area were detected as early as 6 months of age. Despite a less severe morphology with only patches of mononuclear cell infiltration and fibrosis of ~5% by 12 months of age in the heart, cardiac function is clearly affected. High frequency ultrasound reveals a smaller heart size up to 10 months of age. There are significant increases in myocardial thickness and decrease in cardiac output through 12 months. Dysfunction in the heart represents a key marker for evaluating experimental therapies aimed at cardiac muscle.
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Affiliation(s)
- Anthony Blaeser
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Carolinas Medical Center, 1000 Blythe Blvd., Charlotte, NC 28203, United States of America
- * E-mail: (AB); (QLL)
| | - Hiroyuki Awano
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Carolinas Medical Center, 1000 Blythe Blvd., Charlotte, NC 28203, United States of America
| | - Bo Wu
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Carolinas Medical Center, 1000 Blythe Blvd., Charlotte, NC 28203, United States of America
| | - Qi-Long Lu
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Carolinas Medical Center, 1000 Blythe Blvd., Charlotte, NC 28203, United States of America
- * E-mail: (AB); (QLL)
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28
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Trendelenburg-Like Gait, Instability and Altered Step Patterns in a Mouse Model for Limb Girdle Muscular Dystrophy 2i. PLoS One 2016; 11:e0161984. [PMID: 27627455 PMCID: PMC5023177 DOI: 10.1371/journal.pone.0161984] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 08/13/2016] [Indexed: 11/29/2022] Open
Abstract
Limb-girdle muscular dystrophy type 2i (LGMD2i) affects thousands of lives with shortened life expectancy mainly due to cardiac and respiratory problems and difficulty with ambulation significantly compromising quality of life. Limited studies have noted impaired gait in patients and animal models of different muscular dystrophies, but not in animal models of LGMD2i. Our goal, therefore, was to quantify gait metrics in the fukutin-related protein P448L mutant (P448L) mouse, a recently developed model for LGMD2i. The Noldus CatWalk XT motion capture system was used to identify multiple gait impairments. An average galloping body speed of 35 cm/s for both P448L and C57BL/6 wild-type mice was maintained to ensure differences in gait were due only to strain physiology. Compared to wild-type mice, P448L mice reach maximum contact 10% faster and have 40% more paw surface area during stance. Additionally, force intensity at the time of maximum paw contact is roughly 2-fold higher in P448L mice. Paw swing time is reduced in P448L mice without changes in stride length as a faster swing speed compensates. Gait instability in P448L mice is indicated by 50% higher instances of 3 and 4 paw stance support and conversely, 2-fold fewer instances of single paw stance support and no instance of zero paw support. This leads to lower variation of normal step patterns used and a higher use of uncommon step patterns. Similar anomalies have also been noted in muscular dystrophy patients due to weakness in the hip abductor muscles, producing a Trendelenburg gait characterized by “waddling” and more pronounced shifts to the stance leg. Thus, gait of P448L mice replicates anomalies commonly seen in LGMD2i patients, which is not only potentially valuable for assessing drug efficacy in restoring movement biomechanics, but also for better understanding them.
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29
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A New Mouse Model of Limb-Girdle Muscular Dystrophy Type 2I Homozygous for the Common L276I Mutation Mimicking the Mild Phenotype in Humans. J Neuropathol Exp Neurol 2016; 74:1137-46. [PMID: 26574668 DOI: 10.1097/nen.0000000000000260] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Limb-girdle muscular dystrophy type 2I (LGMD2I) is caused by mutations in the Fukutin-related protein (FKRP) gene, leading to inadequate glycosylation of α-dystroglycan, an important protein linking the extracellular matrix to the cytoskeleton. We created a mouse model of the common FKRP L276I mutation and a hemizygous FKRP L276I knockout model. We studied histopathology and protein expression in the models at different ages and found that homozygous FKRP L276I mice developed a mild progressive myopathy with increased muscle regeneration and fibrosis starting from 1 year of age. This was likely caused by progressive loss of α-dystroglycan-specific glycosylation, which was decreased by 78% at 20 months. The homozygous FKRP knockout was embryonic lethal, but the hemizygous L276I model resembled the homozygous FKRP L276I model at comparable ages. These models emphasize the importance of FKRP in maintaining proper glycosylation of α-dystroglycan. The mild progression in the homozygous FKRP L276I model resembles that in patients with LGMD2I who are homozygous for the L276I mutation. This animal model could, therefore, be relevant for understanding the pathophysiology of and developing a treatment strategy for the human disorder.
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30
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Krag TO, Vissing J. A New Mouse Model of Limb-Girdle Muscular Dystrophy Type 2I Homozygous for the Common L276I Mutation Mimicking the Mild Phenotype in Humans. J Neuropathol Exp Neurol 2015. [DOI: 10.1093/jnen/74.12.1137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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31
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Restoration of Functional Glycosylation of α-Dystroglycan in FKRP Mutant Mice Is Associated with Muscle Regeneration. THE AMERICAN JOURNAL OF PATHOLOGY 2015; 185:2025-37. [DOI: 10.1016/j.ajpath.2015.03.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Revised: 03/19/2015] [Accepted: 03/23/2015] [Indexed: 11/19/2022]
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32
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Awano H, Blaeser A, Wu B, Lu P, Keramaris-Vrantsis E, Lu Q. Dystroglycanopathy muscles lacking functional glycosylation of alpha-dystroglycan retain regeneration capacity. Neuromuscul Disord 2015; 25:474-84. [PMID: 25937147 DOI: 10.1016/j.nmd.2015.03.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Revised: 02/03/2015] [Accepted: 03/11/2015] [Indexed: 12/27/2022]
Abstract
In dystroglycanopathies, lack of glycosylated alpha-dystroglycan (α-DG) alters membrane fragility leading to fiber damage and repetitive cycles of muscle degeneration and regeneration. However the effect of the glycosylation of α-DG on muscle regeneration is not clearly understood. In this study, we examined the regenerative capacity of dystrophic muscles in vivo in FKRP mutant and LARGE(myd) mice with little and complete lack of functionally glycosylated α-DG (F-α-DG) respectively. The number of regenerating fibers expressing embryonic myosin heavy chain (eMyHC) in the diseased muscles up to the age of 10 months is higher than or at similar levels to wild type muscle after notexin and polyethyleminine insults. The process of fiber maturation is not significantly affected by the lack of F-α-DG assessed by size distribution. The earlier appearance of a larger number of regenerating fibers after injury is consistent with the observation that the populations of myogenic satellite cells are increased and being readily activated in the dystroglycanopathy muscles. F-α-DG is expressed at trace amounts in undifferentiated myoblasts, but increases in differentiated myotubes in vitro. We therefore conclude that muscle regeneration is not impaired in the early stage of the dystroglycanopathies, and F-α-DG does not play a significant role in myogenic cell proliferation and fiber formation and maturation.
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Affiliation(s)
- Hiroyuki Awano
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Carolinas Medical Center, 1000 Blythe Blvd, Charlotte, NC 28203, USA
| | - Anthony Blaeser
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Carolinas Medical Center, 1000 Blythe Blvd, Charlotte, NC 28203, USA
| | - Bo Wu
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Carolinas Medical Center, 1000 Blythe Blvd, Charlotte, NC 28203, USA
| | - Pei Lu
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Carolinas Medical Center, 1000 Blythe Blvd, Charlotte, NC 28203, USA
| | - Elizabeth Keramaris-Vrantsis
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Carolinas Medical Center, 1000 Blythe Blvd, Charlotte, NC 28203, USA
| | - Qi Lu
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Carolinas Medical Center, 1000 Blythe Blvd, Charlotte, NC 28203, USA.
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33
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Whitmore C, Morgan J. What do mouse models of muscular dystrophy tell us about the DAPC and its components? Int J Exp Pathol 2014; 95:365-77. [PMID: 25270874 PMCID: PMC4285463 DOI: 10.1111/iep.12095] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Accepted: 08/16/2014] [Indexed: 12/17/2022] Open
Abstract
There are over 30 mouse models with mutations or inactivations in the dystrophin-associated protein complex. This complex is thought to play a crucial role in the functioning of muscle, as both a shock absorber and signalling centre, although its role in the pathogenesis of muscular dystrophy is not fully understood. The first mouse model of muscular dystrophy to be identified with a mutation in a component of the dystrophin-associated complex (dystrophin) was the mdx mouse in 1984. Here, we evaluate the key characteristics of the mdx in comparison with other mouse mutants with inactivations in DAPC components, along with key modifiers of the disease phenotype. By discussing the differences between the individual phenotypes, we show that the functioning of the DAPC and consequently its role in the pathogenesis is more complicated than perhaps currently appreciated.
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Affiliation(s)
- Charlotte Whitmore
- Dubowitz Neuromuscular Centre, Molecular Neurosciences Section, Developmental Neurosciences Programme, Institute of Child Health, University College LondonLondon, UK
| | - Jennifer Morgan
- Dubowitz Neuromuscular Centre, Molecular Neurosciences Section, Developmental Neurosciences Programme, Institute of Child Health, University College LondonLondon, UK
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34
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Townsend D. Finding the sweet spot: assembly and glycosylation of the dystrophin-associated glycoprotein complex. Anat Rec (Hoboken) 2014; 297:1694-705. [PMID: 25125182 PMCID: PMC4135523 DOI: 10.1002/ar.22974] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Accepted: 03/27/2014] [Indexed: 01/12/2023]
Abstract
The dystrophin-associated glycoprotein complex (DGC) is a collection of glycoproteins that are essential for the normal function of striated muscle and many other tissues. Recent genetic studies have implicated the components of this complex in over a dozen forms of muscular dystrophy. Furthermore, disruption of the DGC has been implicated in many forms of acquired disease. This review aims to summarize the current state of knowledge regarding the processing and assembly of dystrophin-associated proteins with a focus primarily on the dystroglycan heterodimer and the sarcoglycan complex. These proteins form the transmembrane portion of the DGC and undergo a complex multi-step processing with proteolytic cleavage, differential assembly, and both N- and O-glycosylation. The enzymes responsible for this processing and a model describing the sequence and subcellular localization of these events are discussed.
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Affiliation(s)
- Dewayne Townsend
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, Minnesota
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35
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Praissman JL, Wells L. Mammalian O-mannosylation pathway: glycan structures, enzymes, and protein substrates. Biochemistry 2014; 53:3066-78. [PMID: 24786756 PMCID: PMC4033628 DOI: 10.1021/bi500153y] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
The
mammalian O-mannosylation pathway for protein post-translational
modification is intricately involved in modulating cell–matrix
interactions in the musculature and nervous system. Defects in enzymes
of this biosynthetic pathway are causative for multiple forms of congenital
muscular dystophy. The application of advanced genetic and biochemical
technologies has resulted in remarkable progress in this field over
the past few years, culminating with the publication of three landmark
papers in 2013 alone. In this review, we will highlight recent progress
focusing on the dramatic expansion of the set of genes known to be
involved in O-mannosylation and disease processes, the concurrent
acceleration of the rate of O-mannosylation pathway protein functional
assignments, the tremendous increase in the number of proteins now
known to be modified by O-mannosylation, and the recent progress in
protein O-mannose glycan quantification and site assignment. Also,
we attempt to highlight key outstanding questions raised by this abundance
of new information.
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Affiliation(s)
- Jeremy L Praissman
- Complex Carbohydrate Research Center, Department of Biochemistry and Molecular Biology, The University of Georgia , Athens, Georgia 30602, United States
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Vannoy CH, Xu L, Keramaris E, Lu P, Xiao X, Lu QL. Adeno-associated virus-mediated overexpression of LARGE rescues α-dystroglycan function in dystrophic mice with mutations in the fukutin-related protein. Hum Gene Ther Methods 2014; 25:187-96. [PMID: 24635668 DOI: 10.1089/hgtb.2013.151] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Multiple genes (e.g., POMT1, POMT2, POMGnT1, ISPD, GTDC2, B3GALNT2, FKTN, FKRP, and LARGE) are known to be involved in the glycosylation pathway of α-dystroglycan (α-DG). Mutations of these genes result in muscular dystrophies with wide phenotypic variability. Abnormal glycosylation of α-DG with decreased extracellular ligand binding activity is a common biochemical feature of these genetic diseases. While it is known that LARGE overexpression can compensate for defects in a few aforementioned genes, it is unclear whether it can also rescue defects in FKRP function. We examined adeno-associated virus (AAV)-mediated LARGE or FKRP overexpression in two dystrophic mouse models with loss-of-function mutations: (1) Large(myd) (LARGE gene) and (2) FKRP(P448L) (FKRP gene). The results agree with previous findings that overexpression of LARGE can ameliorate the dystrophic phenotypes of Large(myd) mice. In addition, LARGE overexpression in the FKRP(P448L) mice effectively generated functional glycosylation (hyperglycosylation) of α-DG and improved dystrophic pathologies in treated muscles. Conversely, FKRP transgene overexpression failed to rescue the defect in glycosylation and improve the phenotypes of the Large(myd) mice. Our findings suggest that AAV-mediated LARGE gene therapy may still be a viable therapeutic strategy for dystroglycanopathies with FKRP deficiency.
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Affiliation(s)
- Charles H Vannoy
- 1 McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Carolinas Medical Center , Carolinas Healthcare System, Charlotte, NC 28231
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37
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Blaeser A, Sparks S, Brown SC, Campbell K, Lu Q. Third International Workshop for Glycosylation Defects in Muscular Dystrophies, 18-19 April 2013, Charlotte, USA. Brain Pathol 2014; 24:280-4. [PMID: 24397416 DOI: 10.1111/bpa.12118] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Accepted: 12/18/2013] [Indexed: 12/21/2022] Open
Affiliation(s)
- Anthony Blaeser
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Neuromuscular/ALS Center, Carolinas Medical Center, Carolinas Healthcare System, Charlotte, NC
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