Article

Transcriptional regulation differs in affected facioscapulohumeral muscular dystrophy patients compared to asymptomatic related carriers

Human Genome Research Center, Department of Genetics and Evolutive Biology, Institute of Biosciences, University of São Paulo, 05508-090, São Paulo, Brazil.
Proceedings of the National Academy of Sciences (Impact Factor: 9.67). 05/2009; 106(15):6220-5. DOI: 10.1073/pnas.0901573106
Source: PubMed

ABSTRACT

Facioscapulohumeral muscular dystrophy (FSHD) is a progressive muscle disorder that has been associated with a contraction of 3.3-kb repeats on chromosome 4q35. FSHD is characterized by a wide clinical inter- and intrafamilial variability, ranging from wheelchair-bound patients to asymptomatic carriers. Our study is unique in comparing the gene expression profiles from related affected, asymptomatic carrier, and control individuals. Our results suggest that the expression of genes on chromosome 4q is altered in affected and asymptomatic individuals. Remarkably, the changes seen in asymptomatic samples are largely in products of genes encoding several chemokines, whereas the changes seen in affected samples are largely in genes governing the synthesis of GPI-linked proteins and histone acetylation. Besides this, the affected patient and related asymptomatic carrier share the 4qA161 haplotype. Thus, these polymorphisms by themselves do not explain the pathogenicity of the contracted allele. Interestingly, our results also suggest that the miRNAs might mediate the regulatory network in FSHD. Together, our results support the previous evidence that FSHD may be caused by transcriptional dysregulation of multiple genes, in cis and in trans, and suggest some factors potentially important for FSHD pathogenesis. The study of the gene expression profiles from asymptomatic carriers and related affected patients is a unique approach to try to enhance our understanding of the missing link between the contraction in D4Z4 repeats and muscle disease, while minimizing the effects of differences resulting from genetic background.

Download full-text

Full-text

Available from: Iris Eisenberg
  • Source
    • "Thus, even though the aim of our study was not to identify what distinguishes FSHD from normal muscle, it emerges that taking one “snapshot” of the pathologic process could be not enough to identify the process itself. This strict dependency on the timing and the muscle in which the “snapshot” is taken could have contributed to the diverse results obtained in different FSHD gene expression studies [14], [15], [27], [33]. This constitutes a substantial difference from, for instance, Duchenne muscular dystrophy, in which the molecular signature develops early and remains constant all over the disease course [12]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Facioscapulohumeral muscular dystrophy (FSHD) is one of the most common muscular dystrophies and is characterized by a non-conventional genetic mechanism activated by pathogenic D4Z4 repeat contractions. By muscle Magnetic Resonance Imaging (MRI) we observed that T2-short tau inversion recovery (T2-STIR) sequences identify two different conditions in which each muscle can be found before the irreversible dystrophic alteration, marked as T1-weighted sequence hyperintensity, takes place. We studied these conditions in order to obtain further information on the molecular mechanisms involved in the selective wasting of single muscles or muscle groups in this disease.
    Full-text · Article · Jun 2012 · PLoS ONE
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The polystyrene based barium–magnesium (BMP) composite membrane was prepared by sol–gel method. The physico-chemical characterization of the BMP composite membrane was established by XRD, FTIR and simultaneous SEM studies. The membrane was found to be crystalline in nature with uniform arrangement of particles indicating no sign of visible cracks. Membrane potential is a measurable and important parameter to characterize the charge property of the membrane. Membrane potentials have been measured across the polystyrene based barium–magnesium (BMP) composite membrane separating various 1:1 electrolytes at different concentrations and followed the order KCl
    Full-text · Article · Jul 2011 · Arabian Journal of Chemistry
  • [Show abstract] [Hide abstract]
    ABSTRACT: In vertebrates, overexpression of facioscapulohumeral muscular dystrophy (FSHD) region gene 1 (FRG1) recapitulates the pathophysiology exhibited by FSHD patients, although the role of FRG1 in FSHD remains controversial and no precise function for FRG1 has been described in any organism. To gain insight into the function and potential role of FRG1 in FSHD, we analyzed the highly conserved Caenorhabditis elegans ortholog, frg-1. C. elegans body-wall muscles contain two distinct subcellular pools of FRG-1: nuclear FRG-1, concentrated in the nucleoli; and cytoplasmic FRG-1, associated with the Z-disk and costamere-like structures known as dense bodies. Functionally, we demonstrate that FRG-1 is an F-actin-bundling protein, consistent with its localization to dense bodies; this activity is conserved in human FRG1. This is particularly intriguing because it places FRG-1 along side the list of dense-body components whose vertebrate orthologs are involved in the myriad myopathies associated with disrupted costameres and Z-disks. Interestingly, overexpressed FRG-1 preferentially accumulates in the nucleus and, when overexpressed specifically from the frg-1 promoter, disrupts the adult ventral muscle structure and organization. Together, these data further support a role for FRG1 overexpression in FSHD pathophysiology and reveal the previously unsuspected direct involvement of FRG-1 in muscle structure and integrity.
    No preview · Article · Mar 2010 · Journal of Cell Science
Show more