0000000000118060
AUTHOR
Adolfo López De Munain
Clinical characteristics and outcomes of thymoma-associated myasthenia gravis
[Background and purpose] Prognosis of myasthenia gravis (MG) in patients with thymoma is not well established. Moreover, it is not clear whether thymoma recurrence or unresectable lesions entail a worse prognosis of MG.
Drug‐refractory myasthenia gravis: Clinical characteristics, treatments, and outcome
[Objective] To describe the clinical characteristics and outcomes in patients with refractory myasthenia gravis (MG) and to determine the effectiveness and side effects of the drugs used for their treatment.
Murine muscle engineered from dermal precursors: an in vitro model for skeletal muscle generation, degeneration and fatty infiltration.
Skeletal muscle can be engineered by converting dermal precursors into muscle progenitors and differentiated myocytes. However, the efficiency of muscle development remains relatively low and it is currently unclear if this is due to poor characterization of the myogenic precursors, the protocols used for cell differentiation, or a combination of both. In this study, we characterized myogenic precursors present in murine dermospheres, and evaluated mature myotubes grown in a novel three-dimensional culture system. After 5-7 days of differentiation, we observed isolated, twitching myotubes followed by spontaneous contractions of the entire tissue-engineered muscle construct on an extracellul…
Increased Muscleblind levels by chloroquine treatment improve myotonic dystrophy type 1 phenotypes in in vitro and in vivo models
Myotonic dystrophy type 1 (DM1) is a life-threatening and chronically debilitating neuromuscular disease caused by the expansion of a CTG trinucleotide repeat in the 3′ UTR of the DMPK gene. The mutant RNA forms insoluble structures capable of sequestering RNA binding proteins of the Muscleblind-like (MBNL) family, which ultimately leads to phenotypes. In this work, we demonstrate that treatment with the antiautophagic drug chloroquine was sufficient to up-regulate MBNL1 and 2 proteins in Drosophila and mouse (HSA LR ) models and patient-derived myoblasts. Extra Muscleblind was functional at the molecular level and improved splicing events regulated by MBNLs in all disease models. In vivo,…
Six Serum miRNAs Fail to Validate as Myotonic Dystrophy Type 1 Biomarkers.
Myotonic dystrophy type 1 (DM1) is an autosomal dominant genetic disease caused by expansion of a CTG microsatellite in the 3' untranslated region of the DMPK gene. Despite characteristic muscular, cardiac, and neuropsychological symptoms, CTG trinucleotide repeats are unstable both in the somatic and germinal lines, making the age of onset, clinical presentation, and disease severity very variable. A molecular biomarker to stratify patients and to follow disease progression is, thus, an unmet medical need. Looking for a novel biomarker, and given that specific miRNAs have been found to be misregulated in DM1 heart and muscle tissues, we profiled the expression of 175 known serum miRNAs in …
Preclinical characterization of antagomiR-218 as a potential treatment for myotonic dystrophy
Myotonic dystrophy type 1 (DM1) is a rare neuromuscular disease caused by expansion of unstable CTG repeats in a non-coding region of the DMPK gene. CUG expansions in mutant DMPK transcripts sequester MBNL1 proteins in ribonuclear foci. Depletion of this protein is a primary contributor to disease symptoms such as muscle weakness and atrophy and myotonia, yet upregulation of endogenous MBNL1 levels may compensate for this sequestration. Having previously demonstrated that antisense oligonucleotides against miR-218 boost MBNL1 expression and rescue phenotypes in disease models, here we provide preclinical characterization of an antagomiR-218 molecule using the HSALR mouse model and patient-d…
Clinical and therapeutic features of myasthenia gravis in adults based on age at onset
[Objective] To describe the characteristics of patients with very-late-onset myasthenia gravis (MG).
Distribution and genotype-phenotype correlation of GDAP1 mutations in Spain
AbstractMutations in the GDAP1 gene can cause Charcot-Marie-Tooth disease. These mutations are quite rare in most Western countries but not so in certain regions of Spain or other Mediterranean countries. This cross-sectional retrospective multicenter study analyzed the clinical and genetic characteristics of patients with GDAP1 mutations across Spain. 99 patients were identified, which were distributed across most of Spain, but especially in the Northwest and Mediterranean regions. The most common genotypes were p.R120W (in 81% of patients with autosomal dominant inheritance) and p.Q163X (in 73% of autosomal recessive patients). Patients with recessively inherited mutations had a more seve…
Expanded CTG repeats trigger miRNA alterations in Drosophila that are conserved in myotonic dystrophy type 1 patients
Myotonic dystrophy type 1 (DM1) is caused by the expansion of CTG repeats in the 3' untranslated region of the DMPK gene. Several missplicing events and transcriptional alterations have been described in DM1 patients. A large number of these defects have been reproduced in animal models expressing CTG repeats alone. Recent studies have also reported miRNA dysregulation in DM1 patients. In this work, a Drosophila model was used to investigate miRNA transcriptome alterations in the muscle, specifically triggered by CTG expansions. Twenty miRNAs were differentially expressed in CTG-expressing flies. Of these, 19 were down-regulated, whereas 1 was up-regulated. This trend was confirmed for thos…
Identification and Characterization of the Dermal Panniculus Carnosus Muscle Stem Cells
Summary The dermal Panniculus carnosus (PC) muscle is important for wound contraction in lower mammals and represents an interesting model of muscle regeneration due to its high cell turnover. The resident satellite cells (the bona fide muscle stem cells) remain poorly characterized. Here we analyzed PC satellite cells with regard to developmental origin and purported function. Lineage tracing shows that they originate in Myf5+, Pax3/Pax7+ cell populations. Skin and muscle wounding increased PC myofiber turnover, with the satellite cell progeny being involved in muscle regeneration but with no detectable contribution to the wound-bed myofibroblasts. Since hematopoietic stem cells fuse to PC…