Oculopharyngeal muscular dystrophy (OPMD) is an autosomal dominant disease caused by an alanine tract expansion mutation in Poly(A)-binding protein nuclear 1 (expPABPN1). To model OPMD in a myogenic and physiological context, we generated mouse myoblast cell clones stably expressing either human wild type (WT) or expPABPN1 at low levels. The transgene expression is induced upon myotube differentiation and results in formation of insoluble nuclear PABPN1 aggregates that are similar to the in vivo aggregates. Quantitative analysis of PABPN1 protein in myotube cultures revealed that expPABPN1 accumulation and aggregation is greater than that of the WT protein. In a comparative study we found that aggregation of expPABPN1 is more affected by inhibition of proteasome activity, as compared with the WT PABPN1 aggregation. Consistent with this, in myotubes cultures expressing expPABPN1 deregulation of the proteasome was identified as the most significantly deregulated pathway. Differences in the accumulation of soluble WT and expPABPN1 were consistent with differences in ubiquitination and protein turnover. This study indicates, for the first time, that in myotubes the ratio of soluble to insoluble expPABPN1 is significantly lower compared to that of the WT protein. We suggest that this difference can contribute to muscle weakness in OPMD.
Modeling oculopharyngeal muscular dystrophy in myotube cultures reveals reduced accumulation of soluble mutant PABPN1 protein.
Cell line
View SamplesOculopharyngeal muscular dystrophy (OPMD) is a late-onset progressive muscle disorder caused by a poly-alanine expansion mutation in PABPN1. The hallmark of OPMD is the accumulation of the mutant protein in insoluble nuclear inclusions. The molecular mechanisms associated with disease onset and progression are unknown. We performed a high-throughput cross-species transcriptome study of affected muscles from two OPMD animal models and from patients at pre-symptomatic and symptomatic stages. The most consistently and significantly OPMD-deregulated pathway across species is the ubiquitin-proteasome system (UPS). By analyzing expression profiles, we found that the majority of OPMD-deregulated genes are age-associated. Based on expression trends, disease onset can be separated from progression; the expression profiles of the proteasome-encoding genes are associated with onset but not with progression. In a muscle cell model, proteasome inhibition and the stimulation of immunoproteasome specifically affect the accumulation and aggregation of mutant PABPN1. We suggest that proteasome down-regulation during muscle aging triggers the accumulation of expPABPN1 that in turn enhances proteasome deregulation and leads to intranuclear inclusions (INI) formation.
Deregulation of the ubiquitin-proteasome system is the predominant molecular pathology in OPMD animal models and patients.
Sex, Age, Disease, Disease stage
View SamplesFacioscapulohumeral 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.
DUX4 activates germline genes, retroelements, and immune mediators: implications for facioscapulohumeral dystrophy.
Specimen part
View SamplesWe compared the transcriptomes of EpiSCs maintained in the presence or absence of Wnt pathway inhibitor IWP2. We screened also our gene expression data for potential markers for genuine EpiSCs, maintained in the presence of Wnt inhibition and compared with ESC expression data. We compared the transcriptomes of EpiSCs maintained in the presence or absence of IWP2. The high level of Wnt-induced differentiation occurring in conventional EpiSC cultures may have interfered with the analysis of their characteristics. By applying Wnt inhibitors we are now able to establish the properties of genuine EpiSCs.
Endogenous WNT signals mediate BMP-induced and spontaneous differentiation of epiblast stem cells and human embryonic stem cells.
Specimen part, Treatment
View SamplesWe used RNA-Seq to analyse the interactions between Bmp4 and Wnt at a genome-wide level in EpiSCs treated for 48 hrs with Bmp4 and/or Wnt3a in the presence of Activin and bFGF. Overall design: Control EpiSC were cultured in the presence of IWP2 for 48h. Cells were cultured with BMP4 with or without IWP2; Wnt3a and Wnt3a with BMP4 for 48h.
Endogenous WNT signals mediate BMP-induced and spontaneous differentiation of epiblast stem cells and human embryonic stem cells.
No sample metadata fields
View SamplesPatients with HIV-associated TB are known to experience systemic hyperinflammation, clinically known as immune reconstitution inflammatory syndrome (IRIS), following the commencement of antiretroviral therapy (ART). No prognostic markers or biomarkers have been identified to date and little is known about the mechanism mediating the hyperinflammation. We recruited a prospective cohort of 63 patients with HIV-associated TB, 33 of whom developed TB-IRIS. Of which transcriptomic profiling was performed using longitudinal whole blood RNA samples from 15 non-IRIS and 17 TB-IRIS patients. Transcriptomic signatures that distinguish patients who would eventually develop IRIS were identified as early as week 0.5 (2-5 days post-ART) and predicted a downstream activation of proinflammatory cytokines. At the peak of IRIS (week 2), transcriptomic signatures were overrepresented by innate receptor signaling pathways including toll-like receptor, IL-1 receptor and TREM-1.
HIV-tuberculosis-associated immune reconstitution inflammatory syndrome is characterized by Toll-like receptor and inflammasome signalling.
Specimen part
View SamplesBackground: Colorectal cancers are believed to arise predominantly from adenomas. Although these precancerous lesions have been subjected to extensive clinical, pathological, and molecular analyses, little is currently known about the global gene expression changes accompanying their formation. Results: To characterize the molecular processes underlying the transformation of normal colonic epithelium, we compared the transcriptomes of 32 prospectively collected adenomas with those of normal mucosa from the same individuals. Important differences emerged not only between the expression profiles of normal and adenomatous tissues, but also between those of small and large adenomas. A key feature of the transformation process was the remodeling of the Wnt pathway reflected in patent over- and underexpression of 78 known components of this signaling cascade. Conclusions: Our transcriptomic profiles of normal colonic mucosa and colorectal adenomas shed new light on the early stages of colorectal tumorigenesis.
Transcriptome profile of human colorectal adenomas.
Specimen part, Subject
View SamplesBACKGROUND
Emmprin and survivin predict response and survival following cisplatin-containing chemotherapy in patients with advanced bladder cancer.
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View SamplesCrossing of hDMD mice that contain the full-length 2.3 Mb hDMD gene were crossed with dystrophin-deficient mdx mice and dystrophin and utrophin double-deficient mdx x utrn-/- mice resulted in a full rescue of the dystrophic features of these mice, as concluded from histological analysis. Analysis on Affymetrix gene chips demonstrated that also expression profiles of the dystrophic mice were normalized by crossing with transgenic hDMD mice. This confirms the full functionality of the hDMD transgene in mice.
Generation and characterization of transgenic mice with the full-length human DMD gene.
No sample metadata fields
View SamplesIn this study we determine the transcriptional profile by RNAseq of mESC in the absence of Smad1 and Smad5 and in subpopulation of mESC with different levels of BMP-SMAD activation. Overall design: Transcriptome analysis using RNAseq was performed on 3 biological replicates of BRE negative and positive mESC subpopulations, which were collected in pairs at 3 different times. Transcriptome analysis using RNAseq was performed on Smad1/5 floxed (FL) and knockout (KO) mESC. Two different parental cell lines were used. For each parental cell line we analyzed one Smad1/5 FL sample and two Smad1/5 KO samples, resulting in respectively two and four biological replicates for the FL and KO conditions.
BMP-SMAD Signaling Regulates Lineage Priming, but Is Dispensable for Self-Renewal in Mouse Embryonic Stem Cells.
No sample metadata fields
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