Project description:The gene expression pathways leading to muscle pathology in facioscapulohumeral dystrophy (FSHD) remain to be elucidated. This muscular dystrophy is caused by a contraction of an array of tandem 3.3-kb repeats (D4Z4) at 4q35.2. We compared expression of control and FSHD myoblasts and myotubes (three preparations each) on exon microarrays (Affymetrix Human Exon 1.0 ST) and validated FSHD-specific differences for representative genes by qRT-PCR on additional myoblast cell strains. The FSHD and control myoblasts used for these experiments were shown to grow and differentiate into myotubes equally efficiently as control myoblasts. There were no significant FSHD-control differences in RNA levels for MYOD1 and MYOG at the myoblast and myotube stages and for MYF5 and MYF6 at the myoblast stage. In contrast, 295 other genes were dysregulated at least 2-fold in FSHD vs. control myoblasts (p <0.01, adjusted for multiple comparisons). Remarkably, only 10% of the FSHD-associated gene dysregulation at the myoblast stage was downregulation. At the myotube stage, about ten times as many genes exhibited FSHD-associated downregulated as at the myoblast stage and twice as many genes displayed FSHD-associated upregulation. The FSHD-related changes in RNA levels appear to be due to posttranscriptional as well as transcriptional alterations. Among the prominently dysregulated pathways were signaling and oxidative stress pathways. By comparing expression profiles of control myoblasts and myotubes to each other and to 19 non-muscle cell types profiled identically, our study also revealed many new myogenesis associations for genes not previously annotated as muscle-specific. Keywords: Disease state analysis and time course for differentiation
Project description:Facioscapulohumeral dystrophy (FSHD) is a neuromuscular disease characterized by progressive asymmetric muscle weakness. Myoblasts isolated from FSHD muscles exhibit morphological differentiation defects and show a distinct transcription profile. These abnormalities may be linked to the muscle weakness in FSHD patients. Here, we have tested whether fusion of FSHD myoblasts (obtained from 2 patients) with primary myoblasts isolated from 2 healthy individuals could correct the differentiation defects. Our results show that the number of hybrid myotubes with normal phenotype increased with the percentage of normal myoblasts initially cultured. We demonstrated that a minimum of 50% of normal nuclei is required for a phenotypic correction of the FSHD phenotype. To test the correction on the functional level we analyzed transcriptomic profiles of phenotypically corrected hybrid myotubes. These myotubes were cultured in DMEM with 10% FBS. The present study concerns gene expression of FSHD, normal and hybrid myotubes after RNA extraction (TriPrep NucleoSpin ® kit) according to manufacturer’s instructions. Gene expression was performed in single color on Agilent 8x60K Human whole genome (design 039494) minimum in duplicates in each condition. Transcriptomic profiles of phenotypically corrected hybrid myotubes showed that the expression of deregulated genes in FSHD myotubes became almost normal. We thus propose that while phenotypical and functional correction of FSHD is feasible, it requires more than 50% of normal myoblasts, it creates limitations for cell therapy in the FSHD context.
Project description:The specific gene(s) responsible for FSHD phenotype have not yet been identified. We used the Human GeneChip Exon 1.0 ST platform to analyze the global gene expression profiles of FSHD-1, FSHD-2 and controls during myogenic differentiation. In this dataset, we include the expression data of human primary myoblasts obtained from three FSHD-1 and two FSHD-2 patients, and three healthy controls (CN). This data are used to evaluate the molecular perturbation of FSHD upon muscle differentiation; we compared patients and CN proliferating myoblasts as well as the corresponding myotubes obtained after 8 days of cell differentiation. 16 expression profiles were generated from 6 different cell types: including myoblasts and myotubes from healthy donors and FSHD-1 and FSHD-2 patients. Gene probesets with P < 0.01 and FC > 2 were selected in FSHD-1 assay, whereas P < 0.001 and FC > 2 were used in FSHD-2, in the attempt to overcame problems due to the small sample size analyzed.
Project description:The specific gene(s) responsible for FSHD phenotype have not yet been identified. We used the Human GeneChip Exon 1.0 ST platform to analyze the global gene expression profiles of FSHD-1, FSHD-2 and controls during myogenic differentiation. In this dataset, we include the expression data of human primary myoblasts obtained from three FSHD-1 and two FSHD-2 patients, and three healthy controls (CN). This data are used to evaluate the molecular perturbation of FSHD upon muscle differentiation; we compared patients and CN proliferating myoblasts as well as the corresponding myotubes obtained after 8 days of cell differentiation.
Project description:Facioscapulohumeral dystrophy (FSHD) is one of the most common inherited muscular dystrophies. The causative gene remains controversial and the mechanism of pathophysiology unknown. Here we identify genes associated with germline and early stem cell development as targets of the DUX4 transcription factor, a leading candidate gene for FSHD. The genes regulated by DUX4 are reliably detected in FSHD muscle but not in controls, providing direct support for the model that misexpression of DUX4 is a causal factor for FSHD. Additionally, we show that DUX4 binds and activates LTR elements from a class of MaLR endogenous primate retrotransposons and suppresses the innate immune response to viral infection, at least in part through the activation of DEFB103, a human defensin that can inhibit muscle differentiation. These findings suggest specific mechanisms of FSHD pathology and identify candidate biomarkers for disease diagnosis and progression. [Overexpression experiment] Quadruplicate total RNA samples were collected from control human primary myoblasts transduced with lentivirus carrying DUX4-fl, DUX4-s or GFP (MOI = 15) for 24 h and from untransduced myoblasts. [Defensin experiment] Quadruplicate samples were also collected from myoblasts and myotubes grown in media containing human beta-defensin 3 peptide or in control media.
Project description:Transcriptional profiling of human mesenchymal stem cells comparing normoxic MSCs cells with hypoxic MSCs cells. Hypoxia may inhibit senescence of MSCs during expansion. Goal was to determine the effects of hypoxia on global MSCs gene expression. Two-condition experiment, Normoxic MSCs vs. Hypoxic MSCs.
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)