0000000000084371
AUTHOR
Mouli Chakraborty
Pentamidine rescues contractility and rhythmicity in a Drosophila model of myotonic dystrophy heart dysfunction
Up to 80% of individuals with myotonic dystrophy type 1 (DM1) will develop cardiac abnormalities at some point during the progression of their disease, the most common of which is heart blockage of varying degrees. Such blockage is characterized by conduction defects and supraventricular and ventricular tachycardia, and carries a high risk of sudden cardiac death. Despite its importance, very few animal model studies have focused on the heart dysfunction in DM1. Here, we describe the characterization of the heart phenotype in a Drosophila model expressing pure expanded CUG repeats under the control of the cardiomyocyte-specific driver GMH5-Gal4. Morphologically, expression of 250 CUG repeat…
Modeling of Myotonic Dystrophy Cardiac Phenotypes in Drosophila
After respiratory distress, cardiac dysfunction is the second most common cause of fatality associated with the myotonic dystrophy (DM) disease. Despite the prevalance of heart failure in DM, physiopathological studies on heart symptoms have been relatively scarce because few murine models faithfully reproduce the cardiac disease. Consequently, only a small number of candidate compounds have been evaluated in this specific phenotype. To help cover this gap Drosophila combines the amenability of its invertebrate genetics with the possibility of quickly acquiring physiological parameters suitable for meaningful comparisons with vertebrate animal models and humans. Here we review available des…
Expanded CCUG repeat RNA expression in Drosophila heart and muscle trigger Myotonic Dystrophy type 1-like phenotypes and activate autophagocytosis genes
AbstractMyotonic dystrophies (DM1–2) are neuromuscular genetic disorders caused by the pathological expansion of untranslated microsatellites. DM1 and DM2, are caused by expanded CTG repeats in the 3′UTR of the DMPK gene and CCTG repeats in the first intron of the CNBP gene, respectively. Mutant RNAs containing expanded repeats are retained in the cell nucleus, where they sequester nuclear factors and cause alterations in RNA metabolism. However, for unknown reasons, DM1 is more severe than DM2. To study the differences and similarities in the pathogenesis of DM1 and DM2, we generated model flies by expressing pure expanded CUG ([250]×) or CCUG ([1100]×) repeats, respectively, and compared …
Daunorubicin reduces MBNL1 titration by expanded CUG repeat RNA and rescues cardiac dysfunctions in a Drosophila model of myotonic dystrophy
International audience; Myotonic dystrophy (DM) is a dominantly inherited neuromuscular disorder caused by expression of mutant DMPK transcripts containing expanded CUG repeats. Pathogenic RNA sequesters the muscleblind-like (MBNL) proteins, causing alterations of RNA metabolism. Cardiac dysfunction represents the second most common cause of death in DM1 patients. However, the contribution of MBNL titration in DM1 cardiac dysfunction is unclear. We overexpressed Muscleblind (Mbl), Drosophila MBNL orthologue, in cardiomyocytes of DM1 model flies and observed a rescue of heart dysfunctions, which are characteristic of these model flies and resemble cardiac defects observed in patients. We als…
Generación y caracterización de modelos en Drosophila de disfunción cardiaca en distrofia miotónica
La tesis titulada "Generación y caracterización de los modelos de Drosophila de la disfunción cardíaca en la distrofia miotónica" se realiza mediante la combinación de tres artículos publicados. Después de la dificultad respiratoria, la disfunción cardíaca es la segunda causa más común de muerte asociada con la enfermedad neuromuscular distrofia miotónica (DM). A pesar de la participación central de la insuficiencia cardíaca en la DM, los estudios fisiopatológicos sobre los síntomas cardíacos han sido relativamente escasos porque pocos modelos murinos reproducen fielmente la enfermedad cardíaca. En consecuencia, solo un pequeño número de compuestos candidatos se han evaluado en este fenotip…
The Drosophila junctophilin gene is functionally equivalent to its four mammalian counterparts and is a modifier of a Huntingtin poly-Q expansion and the Notch pathway
[EN] Members of the Junctophilin (JPH) protein family have emerged as key actors in all excitable cells, with crucial implications for human pathophysiology. In mammals, this family consists of four members (JPH1-JPH4) that are differentially expressed throughout excitable cells. The analysis of knockout mice lacking JPH subtypes has demonstrated their essential contribution to physiological functions in skeletal and cardiac muscles and in neurons. Moreover, mutations in the human JPH2 gene are associated with hypertrophic and dilated cardiomyopathies; mutations in JPH3 are responsible for the neurodegenerative Huntington's disease-like-2 (HDL2), whereas JPH1 acts as a genetic modifier in C…