Project description:Facioscapulohumeral muscular dystrophy (FSHD) is linked to contraction of an array of tandem 3.3-kb repeats (D4Z4) at 4q35.2 from 11-100 copies to 1-10 copies. The extent to which D4Z4 contraction at 4q35.2 affects overall 4q35.2 chromatin organization remains unclear. Because DNA replication timing is highly predictive of long-range chromatin interactions, we generated genome-wide replication-timing profiles for FSHD and control myogenic precursor cells. We compared non-immortalized myoblasts from four FSHD patients and three control individuals to each other and to a variety of other human cell types. This study also represents the first genome-wide comparison of replication timing profiles in non-immortalized human cell cultures. Myoblasts from both control and FSHD individuals all shared a myoblast-specific replication profile. In contrast, male and female individuals were readily distinguished by monoallelic differences in replication timing at DXZ4 and other regions across the X chromosome affected by X inactivation. We conclude that replication timing is a robust cell-type specific feature that is unaffected by FSHD-related D4Z4 contraction. Profile comparison of myoblast cultures from four FSHD patients and three control individuals
Project description:Facioscapulohumeral muscular dystrophy (FSHD) is linked to contraction of an array of tandem 3.3-kb repeats (D4Z4) at 4q35.2 from 11-100 copies to 1-10 copies. The extent to which D4Z4 contraction at 4q35.2 affects overall 4q35.2 chromatin organization remains unclear. Because DNA replication timing is highly predictive of long-range chromatin interactions, we generated genome-wide replication-timing profiles for FSHD and control myogenic precursor cells. We compared non-immortalized myoblasts from four FSHD patients and three control individuals to each other and to a variety of other human cell types. This study also represents the first genome-wide comparison of replication timing profiles in non-immortalized human cell cultures. Myoblasts from both control and FSHD individuals all shared a myoblast-specific replication profile. In contrast, male and female individuals were readily distinguished by monoallelic differences in replication timing at DXZ4 and other regions across the X chromosome affected by X inactivation. We conclude that replication timing is a robust cell-type specific feature that is unaffected by FSHD-related D4Z4 contraction.
Project description:We have used a tiled microarray based on the D4Z4 sequence, and hybridized amplified transcripts from facioscapulohumeral muscular dystrophy (FSHD) and control (CTRL) samples to detect D4Z4 related expression.
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 muscular dystrophy (FSHD) is an autosomal dominant disorder linked to contractions of the D4Z4 repeat array in the subtelomeric region of chromosome 4q. By comparing genome-wide gene expression data from muscle biopsies of patients with FSHD to those of 11 other neuromuscular disorders, we intend to identify disease-specific changes which are more likely to be involved in the early stages of the disease progression. The data will help to identify pathological mechanisms involved in FSHD. Experiment Overall Design: Comparison of the profiles of FSHD to 13 other conditions for disease-specific changes. The 13 conditions are NHM (Normal healthy muscle) n=15; JDM (Juvenile dermatomyositis) n=25; HSP (Human spastic paraplegia) n=4; FSHD (facioscapulohumeral dystrophy) unaffected n=5, affected n=9; FKRP (Fukutin related protein deficiency) n=7; ED-L (Emery-Dreifuss muscular dystrophy, lamin A/C deficiency) n=4; ED-E (Emery-Dreifuss muscular dystrophy, emerin deficiency) n=4; DYSF (dysferlinopathy) n=10; DMD (Duchenne Muscular Dystrophy) n=10; CALP (Calpain-3 deficiency) n=10; BMD (Becker Muscular Dystrophy) n=5; AQM (Acute quadriplegic myopathy) n=5; ALS (Amyotrophic lateral sclerosis) n=9.
Project description:Facioscapulohumeral muscular dystrophy (FSHD) is caused by insufficient epigenetic repression of D4Z4 macrosatellite repeat where DUX4, an FSHD causing gene is embedded. There are two forms of FSHD, FSHD1 with contraction of D4Z4 repeat and FSHD2 with chromatin compaction defects mostly due to SMCHD1 mutation. Previous reports showed DUX4-induced gene expression changes as well as changes in microRNA expression in FSHD muscle cells. However, a genome wide analysis of small noncoding RNAs that might be regulated by DUX4 or by mutations in SMCHD1 has not been reported yet. Here, we identified several types of small noncoding RNAs including known microRNAs that are differentially expressed in FSHD2 muscle cells compared to control. Although fewer small RNAs were differentially expressed during muscle differentiation in FSHD2 cells compared to controls, most of the known myogenic microRNAs, such as miR1, miR133a, and miR206 were induced in both FSHD2 and control muscle cells during differentiation. Our small RNA sequencing data analysis also revealed both DUX4- and SMCHD1-specific changes in FSHD2 muscle cells. Six FSHD2 microRNAs were affected by DUX4 overexpression in control myoblasts, whereas increased expression of tRNAs and 5S rRNAs in FSHD2 muscle cells was largely recapitulated in SMCHD1-depleted control myoblasts. Altogether, our studies suggest that the small noncoding RNA transcriptome changes in FSHD2 might be different from those in FSHD1 and that these differences may provide new diagnostic and therapeutic tools specific to FSHD2.
Project description:We have used a tiled microarray based on the D4Z4 sequence, and hybridized amplified transcripts from facioscapulohumeral muscular dystrophy (FSHD) and control (CTRL) samples to detect D4Z4 related expression. Microarrays were analyzed by GenePix Pro 6 (Axon). Local background corrected, median spot intensities were normalized using VSN in R. Due to this normalization strategy, we have treated the microarrays as single channels. The normalized values are uploaded with each sample. Hybridizations were performed in a dye-swap fashion. Samples GSM306099 and GSM306100 are on a single array, and so are GSM306101 and GSM306102, GSM306103 and GSM306104, GSM306105 and GSM306106.
Project description:Facioscapulohumeral muscular dystrophy (FSHD) is a progressive neuromuscular disorder caused by contractions of repetitive elements within the macrosatellite D4Z4 on chromosome 4q35. In order to develop mRNA-based biomarkers of affected muscles, we used GeneChip Gene 1.0 ST arrays for global analysis of gene expression in muscle biopsy specimens obtained from FSHD subjects and their unaffected first degree relatives.
Project description:Total RNA sequencing of human and murine myoblasts and myotubes was extracted, depleted of ribosomal RNA and subjected to Illumina stranded paired end library prep and sequencing. Samples from Duchenne Muscular Dystrophy patients-derived myoblasts were included in this study
Project description:Facioscapulohumeral muscular dystrophy (FSHD) is a hereditary myopathy linked to deletions of the tandemly arrayed D4Z4 macrosatellite repeats at human chromosome 4q35. These deletions accompany local chromatin changes and the anomalous expression of nearby genes FRG2A, DBET, and D4Z4. We discovered that FRG2A is one member of a family of long non-coding RNAs (lncRNA) expressed at elevated levels in skeletal muscle cells in an individual-specific manner. We found that FRG2A lncRNA preferentially associates with rDNA sequences and centromeres, and also promotes the three-dimensional association of centromeres with the nucleolar periphery in FSHD samples. Furthermore, we demonstrate that the elevated FRG2A expression in cells from FSHD patients reduces rDNA transcription and protein synthesis rates.Our results frame a new disease model in which elevated lncRNA expression mediated by deletions of D4Z4 macrosatellite repeats leads to a diminished protein synthesis capacity, thereby contributing to muscle wasting.