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Congenital muscular dystrophy laminin

Jing Zhou, Jianxin Tan, Dingyuan Ma, Jingjing Zhang, Jian Cheng, Chunyu Luo, Gang Liu, Yuguo Wang, Zhengfeng Xu
Merosin-deficient CMD type 1A (MDC1A), caused by mutations of laminin subunit alpha 2 (LAMA2), is a predominant subtype of congenital muscular dystrophy (CMD). Herein, we described a Chinese patient with MDC1A who was admitted to hospital 17 days after birth because of marasmus and feeding difficulties. Mutations were identified by targeted capture and next generation sequencing (NGS) and further confirmed by Sanger sequencing. Paternity was confirmed by short tandem repeat analysis. Physical examination showed malnutrition, poor suck and appendicular hypotonia...
2018: Frontiers in Genetics
Ana Beatriz Delavia Thomasi, Carmen Sonntag, Danilo Fernando Pires, David Zuidema, Antonio Benci, Peter David Currie, Alasdair John Wood
Muscle fiber detachment from myoseptal boundaries is a common finding in zebrafish models of muscular dystrophies. In some instances, there is a weakening of the interaction between muscle fiber and myosepta, which is yet to manifest as a fiber detachment phenotype. Therefore, to push the fiber detachment of muscle, mutant fish but not their wild-type siblings, beyond their binding threshold, a series of small electrical pulses can be applied to the larvae to create a maximal force contraction and ultimately fiber detachment...
January 30, 2018: Zebrafish
Keiu Kask, Laura Tikker, Katrin Ruisu, Sirje Lulla, Eva-Maria Oja, Riho Meier, Raivo Raid, Teet Velling, Tambet Tõnissoo, Margus Pooga
Autosomal recessive disorders such as Fukuyama congenital muscular dystrophy, Walker-Warburg syndrome, and the muscle-eye-brain disease are characterized by defects in the development of patient's brain, eyes, and skeletal muscles. These syndromes are accompanied by brain malformations like type II lissencephaly in the cerebral cortex with characteristic overmigrations of neurons through the breaches of the pial basement membrane. The signaling pathways activated by laminin receptors, dystroglycan and integrins, control the integrity of the basement membrane, and their malfunctioning may underlie the pathologies found in the rise of defects reminiscent of these syndromes...
January 30, 2018: Developmental Neurobiology
Soonsang Yoon, Mary Lou Beermann, Bryant Yu, Di Shao, Markus Bachschmid, Jeffrey Boone Miller
BACKGROUND: Mutations in the LAMA2 gene encoding laminin-α2 cause congenital muscular dystrophy Type 1A (MDC1A), a severe recessive disease with no effective treatment. Previous studies have shown that aberrant activation of caspases and cell death through a pathway regulated by BAX and KU70 is a significant contributor to pathogenesis in laminin-α2-deficiency. OBJECTIVES: To identify mechanisms of pathogenesis in MDC1A. METHODS: We used immunocytochemical and molecular studies of human myogenic cells and mouse muscles-comparing laminin-α2-deficient vs...
December 20, 2017: Journal of Neuromuscular Diseases
Peter D Yurchenco, Karen K McKee, Judith R Reinhard, Markus A Rüegg
Laminins are large heterotrimers composed of the α, β and γ subunits with distinct tissue-specific and developmentally regulated expression patterns. The laminin-α2 subunit, encoded by the LAMA2 gene, is expressed in skeletal muscle, Schwann cells of the peripheral nerve and astrocytes and pericytes of the capillaries in the brain. Mutations in LAMA2 cause the most common type of congenital muscular dystrophies, called LAMA2 MD or MDC1A. The disorder manifests mostly as a muscular dystrophy but slowing of nerve conduction contributes to the disease...
November 27, 2017: Matrix Biology: Journal of the International Society for Matrix Biology
Takenori Shimo, Rika Maruyama, Toshifumi Yokota
During the past 10 years, antisense oligonucleotide-mediated exon skipping and splice modulation have proven to be powerful tools for correction of mRNA splicing in genetic diseases. In 2016, the US Food and Drug Administration (FDA)-approved Exondys 51 (eteplirsen) and Spinraza (nusinersen), the first exon skipping and exon inclusion drugs, to treat patients with Duchenne muscular dystrophy (DMD) and spinal muscular atrophy (SMA), respectively. The exon skipping of DMD mRNA aims to restore the disrupted reading frame using antisense oligonucleotides (AONs), allowing the production of truncated but partly functional dystrophin proteins, and slow down the progression of the disease...
2018: Methods in Molecular Biology
Bernardo Moreira Soares Oliveira, Madeleine Durbeej, Johan Holmberg
MicroRNAs (miRNAs) are short non-coding RNAs that modulate gene expression post-transcriptionally. Current evidence suggests that miR-21 plays a significant role in the progression of fibrosis in muscle diseases. Laminin-deficient congenital muscular dystrophy (LAMA2-CMD) is a severe form of congenital muscular dystrophy caused by mutations in the gene encoding laminin α2 chain. Mouse models dy3K/dy3K and dy2J/dy2J, respectively, adequately mirror severe and milder forms of LAMA2-CMD. Both human and mouse LAMA2-CMD muscles are characterized by extensive fibrosis and considering that fibrosis is the final step that destroys muscle during the disease course, anti-fibrotic therapies may be effective strategies for prevention of LAMA2-CMD...
2017: PloS One
Maria Sframeli, Anna Sarkozy, Marta Bertoli, Guja Astrea, Judith Hudson, Mariacristina Scoto, Rachael Mein, Michael Yau, Rahul Phadke, Lucy Feng, Caroline Sewry, Adeline Ngoh Seow Fen, Cheryl Longman, Gary McCullagh, Volker Straub, Stephanie Robb, Adnan Manzur, Kate Bushby, Francesco Muntoni
Congenital muscular dystrophies (CMDs) are clinically and genetically heterogeneous conditions; some fatal in the first few years of life and with central nervous system involvement, whereas others present a milder course. We provide a comprehensive report of the relative frequency and clinical and genetic spectrum of CMD in the UK. Genetic analysis of CMD genes in the UK is centralised in London and Newcastle. Between 2001 and 2013, a genetically confirmed diagnosis of CMD was obtained for 249 unrelated individuals referred to these services...
September 2017: Neuromuscular Disorders: NMD
Judith R Reinhard, Shuo Lin, Karen K McKee, Sarina Meinen, Stephanie C Crosson, Maurizio Sury, Samantha Hobbs, Geraldine Maier, Peter D Yurchenco, Markus A Rüegg
LAMA2-related muscular dystrophy (LAMA2 MD or MDC1A) is the most frequent form of early-onset, fatal congenital muscular dystrophies. It is caused by mutations in LAMA2, the gene encoding laminin-α2, the long arm of the heterotrimeric (α2, β1, and γ1) basement membrane protein laminin-211 (Lm-211). We establish that despite compensatory expression of laminin-α4, giving rise to Lm-411 (α4, β1, and γ1), muscle basement membrane is labile in LAMA2 MD biopsies. Consistent with this deficit, recombinant Lm-411 polymerized and bound to cultured myotubes only weakly...
June 28, 2017: Science Translational Medicine
Raffaella Willmann, Heather Gordish-Dressman, Sarina Meinen, Markus A Rüegg, Qing Yu, Kanneboyina Nagaraju, Ayar Kumar, Mahasweta Girgenrath, Caroline B M Coffey, Vivian Cruz, Pam M Van Ry, Laurent Bogdanik, Cathleen Lutz, Anne Rutkowski, Dean J Burkin
Laminin-α2 related Congenital Muscular Dystrophy (LAMA2-CMD) is a progressive muscle disease caused by partial or complete deficiency of laminin-211, a skeletal muscle extracellular matrix protein. In the last decade, basic science research has queried underlying disease mechanisms in existing LAMA2-CMD murine models and identified possible clinical targets and pharmacological interventions. Experimental rigor in preclinical studies is critical to efficiently and accurately quantify both negative and positive results, degree of efficiency of potential therapeutics and determine whether to move a compound forward for additional preclinical testing...
2017: Journal of Neuromuscular Diseases
Ricardo A Maselli, Juan Arredondo, Jessica Vázquez, Jessica X Chong, Michael J Bamshad, Deborah A Nickerson, Marian Lara, Fiona Ng, Victoria L Lo, Peter Pytel, Craig M McDonald
Defects in genes encoding the isoforms of the laminin alpha subunit have been linked to various phenotypic manifestations, including brain malformations, muscular dystrophy, ocular defects, cardiomyopathy, and skin abnormalities. We report here a severe defect of neuromuscular transmission in a consanguineous patient with a homozygous variant in the laminin alpha-5 subunit gene (LAMA5). The variant c.8046C>T (p.Arg2659Trp) is rare and has a predicted deleterious effect. The affected individual, who also carries a rare homozygous sequence variant in LAMA1, had muscle weakness, myopia, and facial tics...
August 2017: American Journal of Medical Genetics. Part A
Ida Signe Bohse Larsen, Yoshiki Narimatsu, Hiren Jitendra Joshi, Zhang Yang, Oliver J Harrison, Julia Brasch, Lawrence Shapiro, Barry Honig, Sergey Y Vakhrushev, Henrik Clausen, Adnan Halim
Protein O-mannosylation is found in yeast and metazoans, and a family of conserved orthologous protein O-mannosyltransferases is believed to initiate this important post-translational modification. We recently discovered that the cadherin superfamily carries O-linked mannose (O-Man) glycans at highly conserved residues in specific extracellular cadherin domains, and it was suggested that the function of E-cadherin was dependent on the O-Man glycans. Deficiencies in enzymes catalyzing O-Man biosynthesis, including the two human protein O-mannosyltransferases, POMT1 and POMT2, underlie a subgroup of congenital muscular dystrophies designated α-dystroglycanopathies, because deficient O-Man glycosylation of α-dystroglycan disrupts laminin interaction with α-dystroglycan and the extracellular matrix...
July 7, 2017: Journal of Biological Chemistry
Andreia M Nunes, Ryan D Wuebbles, Apurva Sarathy, Tatiana M Fontelonga, Marianne Deries, Dean J Burkin, Sólveig Thorsteinsdóttir
Merosin-deficient congenital muscular dystrophy type 1A (MDC1A) is a dramatic neuromuscular disease in which crippling muscle weakness is evident from birth. Here, we use the dyW mouse model for human MDC1A to trace the onset of the disease during development in utero. We find that myotomal and primary myogenesis proceed normally in homozygous dyW-/- embryos. Fetal dyW-/- muscles display the same number of myofibers as wildtype (WT) muscles, but by E18.5 dyW-/- muscles are significantly smaller and muscle size is not recovered post-natally...
June 1, 2017: Human Molecular Genetics
Kinga I Gawlik, Johan Holmberg, Martina Svensson, Mikaela Einerborg, Bernardo M S Oliveira, Tomas Deierborg, Madeleine Durbeej
A large number of human diseases are caused by chronic tissue injury with fibrosis potentially leading to organ failure. There is a need for more effective anti-fibrotic therapies. Congenital muscular dystrophy type 1A (MDC1A) is a devastating form of muscular dystrophy caused by laminin α2 chain-deficiency. It is characterized with early inflammation and build-up of fibrotic lesions, both in patients and MDC1A mouse models (e.g. dy(3K)/dy(3K)). Despite the enormous impact of inflammation on tissue remodelling in disease, the inflammatory response in MDC1A has been poorly described...
March 10, 2017: Scientific Reports
Masamichi Nagae, Sushil K Mishra, Makiko Neyazaki, Rika Oi, Akemi Ikeda, Naohiro Matsugaki, Satoko Akashi, Hiroshi Manya, Mamoru Mizuno, Hirokazu Yagi, Koichi Kato, Toshiya Senda, Tamao Endo, Terukazu Nogi, Yoshiki Yamaguchi
Orchestration of the multiple enzymes engaged in O-mannose glycan synthesis provides a matriglycan on α-dystroglycan (α-DG) which attracts extracellular matrix (ECM) proteins such as laminin. Aberrant O-mannosylation of α-DG leads to severe congenital muscular dystrophies due to detachment of ECM proteins from the basal membrane. Phosphorylation at C6-position of O-mannose catalyzed by protein O-mannosyl kinase (POMK) is a crucial step in the biosynthetic pathway of O-mannose glycan. Several mis-sense mutations of the POMK catalytic domain are known to cause a severe congenital muscular dystrophy, Walker-Warburg syndrome...
April 2017: Genes to Cells: Devoted to Molecular & Cellular Mechanisms
Sarah J Smith, Jeffrey C Wang, Vandana A Gupta, James J Dowling
Merosin deficient congenital muscular dystrophy (MDC1A) is a severe neuromuscular disorder with onset in infancy that is associated with severe morbidities (particularly wheelchair dependence) and early mortality. It is caused by recessive mutations in the LAMA2 gene that encodes a subunit of the extracellular matrix protein laminin 211. At present, there are no treatments for this disabling disease. The zebrafish has emerged as a powerful model system for the identification of novel therapies. However, drug discovery in the zebrafish is largely dependent on the identification of phenotypes suitable for chemical screening...
2017: PloS One
Carmel Nichols, Minal S Jain, Katherine G Meilleur, Tianxia Wu, James Collins, Melissa R Waite, Jahannaz Dastgir, Anam Salman, Sandra Donkervoort, Tina Duong, Katherine Keller, Meganne E Leach, Donovan J Lott, Michelle N McGuire, Leslie Nelson, Anne Rutkowski, Carole Vuillerot, Carsten G Bönnemann, Tanya J Lehky
INTRODUCTION: Electrical impedance myography (EIM) is a noninvasive electrophysiological technique that characterizes muscle properties through bioimpedance. We compared EIM measurements to function, strength, and disease severity in a population with congenital muscular dystrophy (CMD). METHODS: Forty-one patients with CMD, either collagen 6 related disorders (COL6-RD; n = 21) or laminin α-2-related disorders (LAMA2-RD; n = 20), and 21 healthy pediatric controls underwent 2 yearly EIM exams...
January 2018: Muscle & Nerve
Steven D Funk, Jeffrey H Miner
Muscular dystrophies result from a defect in the linkage between the muscle fiber cytoskeleton and the basement membrane (BM). Congenital muscular dystrophy type MDC1A is caused by mutations in laminin α2 that either reduce its expression or impair its ability to polymerize within the muscle fiber BM. Defects in this BM lead to muscle fiber damage from the force of contraction. In this issue of the JCI, McKee and colleagues use a laminin polymerization-competent, designer chimeric BM protein in vivo to restore function of a polymerization-defective laminin, leading to normalized muscle structure and strength in a mouse model of MDC1A...
March 1, 2017: Journal of Clinical Investigation
Karen K McKee, Stephanie C Crosson, Sarina Meinen, Judith R Reinhard, Markus A Rüegg, Peter D Yurchenco
Mutations in laminin α2-subunit (Lmα2, encoded by LAMA2) are linked to approximately 30% of congenital muscular dystrophy cases. Mice with a homozygous mutation in Lama2 (dy2J mice) express a nonpolymerizing form of laminin-211 (Lm211) and are a model for ambulatory-type Lmα2-deficient muscular dystrophy. Here, we developed transgenic dy2J mice with muscle-specific expression of αLNNd, a laminin/nidogen chimeric protein that provides a missing polymerization domain. Muscle-specific expression of αLNNd in dy2J mice resulted in strong amelioration of the dystrophic phenotype, manifested by the prevention of fibrosis and restoration of forelimb grip strength...
March 1, 2017: Journal of Clinical Investigation
Roxanna M Bendixen, Jocelyn Butrum, Mina S Jain, Rebecca Parks, Bonnie Hodsdon, Carmel Nichols, Michelle Hsia, Leslie Nelson, Katherine C Keller, Michelle McGuire, Jeffrey S Elliott, Melody M Linton, Irene C Arveson, Fatou Tounkara, Ruhi Vasavada, Elizabeth Harnett, Monal Punjabi, Sandra Donkervoort, Jahannaz Dastgir, Meganne E Leach, Anne Rutkowski, Melissa Waite, James Collins, Carsten G Bönnemann, Katherine G Meilleur
Congenital muscular dystrophy (CMD) comprises a rare group of genetic muscle diseases that present at birth or early during infancy. Two common subtypes of CMD are collagen VI-related muscular dystrophy (COL6-RD) and laminin alpha 2-related dystrophy (LAMA2-RD). Traditional outcome measures in CMD include gross motor and mobility assessments, yet significant motor declines underscore the need for valid upper extremity motor assessments as a clinical endpoint. This study validated a battery of upper extremity measures in these two CMD subtypes for future clinical trials...
March 2017: Neuromuscular Disorders: NMD
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