Project description:Immortalized myoblasts obtained from healthy and Duchenne patients where induced to fuse into multi-nucleated myotubes and Bru-seq was performed
Project description:hTERT/cdk4 immortalized myogenic human cell lines represent an important tool for skeletal muscle research, being used as therapeutically-pertinent models of various neuromuscular disorders and in numerous fundamental studies of muscle cell function. However, the cell cycle is linked to other cellular processes such as integrin regulation, the PI3K/Akt pathway, and microtubule stability, raising the question as to whether transgenic modification of the cell cycle results in secondary effects that could undermine the validity of these cell models. Here we subjected healthy and disease lines to intensive transcriptomic analysis, comparing immortalized lines with their parent primary populations in both differentiated and undifferentiated states, and testing their myogenic character by comparison with non-myogenic (CD56-negative) cells. We found that immortalization has no measurable effect on the myogenic cascade or on any other cellular processes, and that it was protective against the systems level effects of senescence that are observed at higher division counts of primary cells. This dataset includes gene expression profiles for 94 samples comprising primary myoblasts and their corresponding immortalized clones in both differentiated and undifferentiated states (average of 4 cell culture replicates each) from 5 human subjects (2 healthy and 3 Duchenne muscular dystropy - DMD), together with primary populations of non-myogenic (CD56-ve) cells from the muscles of 8 other human subjects. Total RNA was extracted from, myoblasts, myotubes (after 9 days of differentiation), or CD56-ve cells by dissolving cell pellets in TRIzol then using PureLink RNA Mini Kit.
Project description:BrU incorporation into nascent RNA followed by immunoprecipitation with a BrU specific antibody. The nascent RNA was subsequently eluted with BrU competition.
Project description:Despite the discovery of many genetic risk factors, the cause of the motor neuron death that drives terminal pathology in Amyotrophic Lateral Sclerosis (ALS) remains unknown. We report that the skeletal muscle of ALS patients secretes exosomal vesicles that are specifically toxic to motor neurons. This could not be attributed to a trivial down-stream consequence of muscle denervation. In a study of muscle biopsies and biopsy-derived denervation-naïve differentiated muscle stem cells (myotubes) from 67 human subjects, including healthy and disease controls, ALS myotubes had a consistent signature of disrupted exosome biogenesis and RNA-processing, and their exosomes induced shortened, less branched, neurites, greater death, and disrupted localization of RNA and RNA-processing proteins in motor neurons. Toxicity was dependent on presence of the FUS protein, which is highly expressed in recipient motor neurons. As part of this work, we carried out gene expression analysis of myotubes (differentiated myoblasts) comparing ALS against two other motor neuron disorders as disease controls (SBMA, Spinal and bulbar muscular atrophy; and Spinal Muscular Atrophy Type 4, SMA-IV) and healthy controls.
Project description:BrU incorporation into nascent RNA followed by immunoprecipitation with a BrU specific antibody. The nascent RNA was subsequently eluted with BrU competition.
Project description:Expression data from 22 human myotubes (7 healthy controls, 4 Dysferlinopathy (DYSF), 4 Caveolinopathy 3 (CAV3), 4 Facioscapulohumeral muscular dystrophy(FSHD) and 3 Four and a half LIM 1 protein deficiency FHL1).cDNA microarray data showed that cyclin A1 levels are specifically elevated in FSHD vs. other muscular disorders such as CAV3, DYSF, FHL1 and healthy control. Data could be confirmed with RT-PCR and Western blot analysis showing up-regulated levels of cyclin A1 also on the protein level. Comparison of gene expression among 4 different muscular dystrophies and helathy controls. Looking for genes expression specifically changed (down/upregulated) in FSHD. In these data sheet we include expression data obtained for human cells lines derived from human V.lateralis muscle, shown as mean value. From 59 different expressed genes, Cyclin A1 was selected as a highly overexpressed (28 fold) gene in FSHD if compared to DYSF, CAV3, FHL1 and healyhy controls. Expression data from 22 human myotubes (7 healthy controls, 4 Dysferlinopathy (DYSF), 4 Caveolinopathy 3 (CAV3), 4 Facioscapulohumeral muscular dystrophy(FSHD) and 3 Four and a half LIM 1 protein deficiency FHL1)
Project description:Metabolically healthy skeletal muscle is characterized by the ability to switch easily between glucose and fat oxidation, whereas loss of this ability seems to be related to insulin resistance. The aim of this study was to investigate whether different fatty acids (FAs) and the LXR ligand T0901317 affected metabolic switching in human skeletal muscle cells (myotubes). Pretreatment of myotubes with eicosapentaenoic acid (EPA) increased suppressibility, the ability of glucose to suppress FA oxidation, and metabolic flexibility, the ability to increase FA oxidation when changing from “fed” to “fasted” state. Adaptability, the capacity to increase FA oxidation with increasing FA availability, was increased after pretreatment with EPA, linoleic acid (LA) and palmitic acid (PA). T0901317 counteracted the effect of EPA on suppressibility and adaptability, but did not affect these parameters alone. EPA itself accumulated less, however, EPA, LA, OA and T0901317 increased the number of lipid droplets (LDs) in myotubes, whereas LD size and mitochondria amount were independent of pretreatment. Microarray analysis showed that EPA regulated more genes than the other FAs. Some pathways involved in carbohydrate metabolism were induced only by EPA. The present study suggests a possible favorable effect of EPA on skeletal muscle metabolic switching and glucose utilization. Keywords: Analysis of target gene regulation by using microarrays. Primary human myotubes, derived from 3 healthy, female donors, were preincubated with different fatty acids (oleic acid [OA], palmitic acid [PA], eicosapentaenoic acid [EPA] or linoleic acid [LA], each at 100 µM) or bovine serum albumin [BSA] (40 µM) for 24 h.