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).
Gene expression during normal and FSHD myogenesis.
Specimen part
View SamplesImplantation is dependent on synchronized interactions between the conceptus and surrounding decidual cells but the involvement of clock genes in this process is not well understood. Circadian oscillations are predicated on transcriptional-translational feedback loops, which balance the activities of the transcriptional activators CLOCK and BMAL1 and repressors encoded by PER and CRY genes. Here we show that loss of PER2 expression silences circadian oscillations in decidualizing human endometrial stromal cells (HESCs). Downregulation was preceded by reduced CLOCK binding to a noncanonical E-box enhancer in the PER2 promoter and occurred between 12 - 24 h after exposure to a deciduogenic stimulus. RNA sequencing revealed that premature inhibition of PER2 by siRNA knockdown leads to a grossly disorganised decidual response. Gene ontology analysis highlighted a preponderance of cell cycle regulators amongst the 1,121 genes perturbed upon PER2 knockdown. Congruently, PER2 inhibition abrogated mitotic expansion of differentiating HESCs by inducing cell cycle block at G2/M. Analysis of mid-luteal endometrial biopsies revealed an inverse correlation between PER2 transcript levels and the number of miscarriages in women suffering reproductive failure. Thus, PER2 synchronizes mitotic expansion of HESCs with a periodic decidual gene expression; uncoupling of these events may cause persistent pregnancy failure. Overall design: Endometrial mRNA profiles of paired control (siRNA-NT) and siRNA-PER2 were generated by deep sequencing, in triplicate using Illumina
The clock protein period 2 synchronizes mitotic expansion and decidual transformation of human endometrial stromal cells.
No sample metadata fields
View SamplesSpaceflight results in a number of adaptations to skeletal muscle, including atrophy and shifts towards faster muscle fiber types. To identify changes in gene expression that may underlie these adaptations, microarray expression analysis was performed on gastrocnemius from mice flown on the STS-108 shuttle flight (11 days, 19 hours) versus mice maintained on earth for the same period. Additionally, to identify changes that were due to unloading and reloading, microarray analyses were conducted on calf muscle from ground-based mice subjected to hindlimb suspension (12 days) and mice subjected to hindlimb suspension plus a brief period of reloading (3.5 hours) to simulate the time between landing and sacrifice of the spaceflight mice.
Effects of spaceflight on murine skeletal muscle gene expression.
No sample metadata fields
View SamplesThe proneural NEUROG2 is essential for neuronal commitment, cell cycle exit and neuronal differentiation. Characterizing genes networks regulated downstream of NEUROG2 is therefore of prime importance. To identify NEUROG2 early response genes, we combined gain of function in the neural tube with a global detection of modified transcripts using microarrays. We included in our study a mutant form of NEUROG2 (NEUROG2AQ) that cannot bind DNA and cannot trigger neurogenesis. Using this approach, we identified 942 genes modified at the onset of NEUROG2 activation. The global analysis of functions regulated by NEUROG2 allowed unmasking its rapid impact on cell cycle control. We found that NEUROG2 specifically represses a subset of cyclins acting at the G1 and S phases of the cell cycle, thereby impeding S phase re-entry. This repression occurs before modification of p27kip1, indicating that the decision to leave the cell cycle precedes the activation of this Cyclin-dependant Kinase Inhibitor. Moreover, NEUROG2 down-regulates only one of the D-type cyclins, cyclinD1, and maintaining cyclinD1 blocks the ability of the proneural to trigger cell cycle exit, without altering its capacity to trigger neuronal differentiation. The fact that NEUROG2 represses a subset but not all cell cycle regulators indicates that cell cycle exit is not an indirect consequence of neuronal differentiation but is precisely controlled by NEUROG2. Altogether our findings indicate that NEUROG2, by specifically repressing G1 and S cyclins, allows committed neuronal precursors to perform their last mitosis but blocks their re-entry in the cell cycle, thus favouring cell cycle exit.
NEUROG2 drives cell cycle exit of neuronal precursors by specifically repressing a subset of cyclins acting at the G1 and S phases of the cell cycle.
Specimen part, Treatment
View SamplesTranscription factors that regulate quiescence, proliferation, and homing of lymphocytes are critical for effective immune system function. In the present study, we demonstrated that the transcription factor ELF4 directly activates the tumor suppressor KLF4 downstream of T cell receptor (TCR) signaling to induce cell cycle arrest in nave CD8+ T cells. Elf4- and Klf4-deficient mice accumulated CD8+CD44hi T cells during steady-state conditions and generated more memory T cells after immunization. The homeostatic expansion of CD8+CD44hi T cells in Elf4-null mice resulted in a redistribution of cells to non-lymphoid tissue due to reduced expression of the transcription factor KLF2, and the surface proteins CCR7 and CD62L. This work describes the combinatorial role of lymphocyte-intrinsic factors in the control of T cell homeostasis, activation and homing.
Transcription factor ELF4 controls the proliferation and homing of CD8+ T cells via the Krüppel-like factors KLF4 and KLF2.
Specimen part
View SamplesWe compared the gene expression in roots between WT and uri mutant under +Fe and -Fe conditions using ATH1 microarray analysis to explore which genes are affected by the loss of URI function.
The iron deficiency response in <i>Arabidopsis thaliana</i> requires the phosphorylated transcription factor URI.
Specimen part
View SamplesMitochondrial biogenesis is regulated by signaling pathways sensitive to extracellular conditions and to the internal environment of the cell. We found that deletion of protein phosphatase 2A (PP2A) or of protein phosphatase 6 (PP6) diminishes the nuclear transcriptional response associated with mtDNA damage. Overall design: Six samples were analyzed to determine message RNA levels.
Deletion of conserved protein phosphatases reverses defects associated with mitochondrial DNA damage in Saccharomyces cerevisiae.
Specimen part, Subject
View SamplesUtilizing glycerol and cardiotoxin (CTX) injections in the tibialis anterior muscles of M. musculus provides models of skeletal muscle damages followed by skeletal muscle regeneration. In particular, glycerol-induced muscle regeneration is known to be associated with ectopic adipogenesis. We characterized genome-wide expression profiles of tibialis anterior muscles from wild-type mice injured by either glycerol or CTX injection. Our goal was to detect gene expression changes during the time course of glycerol-induced and CTX-induced muscle regeneration models, that can lead to ectopic adipocyte accumulation.
Genomic profiling reveals that transient adipogenic activation is a hallmark of mouse models of skeletal muscle regeneration.
Sex, Age, Specimen part
View SamplesChronic inflammation during placental malaria (PM) caused by Plasmodium falciparum is most frequent in first-time mothers and is associated with poor maternal and fetal outcomes. In the first genome wide analysis of the local human response to sequestered malaria parasites, we identified genes associated with chronic PM, then localized the corresponding proteins and immune cell subsets in placental cryosections.
Genome-wide expression analysis of placental malaria reveals features of lymphoid neogenesis during chronic infection.
No sample metadata fields
View SamplesStreptococcus suis is a major swine pathogen that can be transmitted to humans causing severe symptoms. A large human outbreak was described in China, where approximately 25% out of 215 infected humans developed an unusual streptococcal toxic shock-like syndrome (STSLS). Albeit increased expression of inflammatory mediators following infection by the Chinese S. suis strain was suggested as responsible for STSLS case severity, the mechanisms involved are still poorly understood. In this study, we investigated the host innate immune response to infection by either one of 3 strains of S. suis: 89-1591 (Canadian, intermediate virulence), P1/7 (European, high virulence), and SC84 (Chinese, epidemic strain). Using Illumina microarray and validating those results with qPCR and Luminex assay, infected mice showed elevated expression of mainly pro-inflammatory chemokine and cytokine genes. Generally, pro-inflammatory genes were expressed at a higher level in mice infected with S. suis strain SC84 > P1/7 > 89-1591. Interestingly, IFN was expressed at much higher levels only in mice infected with the S. suis strain SC84, which could potentially explain some of the STSLS symptoms. IFN-KO mice infected with SC84 showed better survival than WT mice while no differences was seen in mice infected with highly virulent P1/7 strain. Overall, our results show an important role of IFN in S. suis infections and might explain in part the increased virulence of SC84 responsible for a recent outbreak in China.
Exacerbated type II interferon response drives hypervirulence and toxic shock by an emergent epidemic strain of Streptococcus suis.
Sex, Specimen part
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