Needle biopsies were obtained from the vastus lateralis muscle of 6 healthy, sedentary, 672.5 year-old males before and after 3 months of training.
Effects of aerobic training on gene expression in skeletal muscle of elderly men.
No sample metadata fields
View SamplesApoptosis is a controlled cell-death process mediated inter alia by proteins of the Bcl-2 family. Some proteins previously shown to promote the apoptotic process were found to have non-apoptotic functions as well. Microglia, the resident immune cells of the central nervous system, respond to brain derangements by becoming activated to contend with the brain damage. Activated microglia can also undergo activation-induced cell death. Previous studies have addressed the role of core apoptotic proteins in the death process, but whether or not these proteins also play a role in the activation process has not been reported. Here we explore the effect of the BH3-only protein Bid on the immunological features of microglia by subjecting both WT and Bid deficient primary neonatal microglial cultures to LPS treatment (100 ng/ml, 3h) or left untreated (control) and analyzing their transcription profiles in order to study the role of Bid.
Bid regulates the immunological profile of murine microglia and macrophages.
Specimen part
View SamplesNaïve and primed pluripotent states retain distinct molecular properties, yet limited knowledge exists on how their state transitions are regulated. Here we identify Mettl3, an N6-Methyladenosine (m6A) transferase, as a regulator for terminating murine naïve pluripotency. Mettl3 knockout pre-implantation epiblasts and naïve embryonic stem cells (ESCs) are depleted for m6A in mRNAs and yet, are viable. However, they fail to adequately terminate their naïve state, and subsequently undergo aberrant and restricted lineage priming at the post-implantation stage, leading to early embryonic lethality. m6A predominantly and directly reduces mRNA stability, including that of key naïve pluripotency promoting transcripts. This study highlights a critical role for an mRNA epigenetic modification in vivo, and identifies regulatory modules that functionally influence naïve and primed pluripotency in an opposing manner. Overall design: 3'' polyA RNA-sequencing (equivalent to Digital Gene Expression) measured in mouse Embryonic Stem Cells (ESCs) and mouse Embriod bodies (EBs) 0,4 & 8 hours after treatment with Actinomycin which halts transcription. Measured in both WT and Mettl3-KO cells.
Stem cells. m6A mRNA methylation facilitates resolution of naïve pluripotency toward differentiation.
No sample metadata fields
View SamplesNaïve and primed pluripotent states retain distinct molecular properties, yet limited knowledge exists on how their state transitions are regulated. Here, we identify Mettl3, an N6-methyladenosine (m6A) transferase, as a regulator for terminating murine naïve pluripotency. Mettl3 knockout pre-implantation epiblasts and naïve embryonic stem cells (ESCs) are depleted for m6A in mRNAs and yet, are viable. However, they fail to adequately terminate their naïve state, and subsequently undergo aberrant and restricted lineage priming at the post-implantation stage, leading to early embryonic lethality. m6A predominantly and directly reduces mRNA stability, including that of key naïve pluripotency promoting transcripts. This study highlights a critical role for an mRNA epigenetic modification in vivo, and identifies regulatory modules that functionally influence naïve and primed pluripotency in an opposing manner. Overall design: polyA RNA-seq was measured in mouse embryonic stem cells (ESCs) and embroid bodies (EBs), each in WT and in Mettl3-KO cell lines. RNA-seq was measured also from WT mouse embronic fibroblasts (MEF). 3 biological replicates are available from ESCs and 2 from EBs. Replicate C in ESCs was measured alongside protein levels (SILAC) and was used for the analysis of that assay.
Stem cells. m6A mRNA methylation facilitates resolution of naïve pluripotency toward differentiation.
No sample metadata fields
View SamplesNaïve and primed pluripotent states retain distinct molecular properties, yet limited knowledge exists on how their state transitions are regulated. Here we identify Mettl3, an N6-Methyladenosine (m6A) transferase, as a regulator for terminating murine naïve pluripotency. Mettl3 knockout pre-implantation epiblasts and naïve embryonic stem cells (ESCs) are depleted for m6A in mRNAs and yet, are viable. However, they fail to adequately terminate their naïve state, and subsequently undergo aberrant and restricted lineage priming at the post-implantation stage, leading to early embryonic lethality. m6A predominantly and directly reduces mRNA stability, including that of key naïve pluripotency promoting transcripts. This study highlights a critical role for an mRNA epigenetic modification in vivo, and identifies regulatory modules that functionally influence naïve and primed pluripotency in an opposing manner. Overall design: Ribosome footprint (Ribo-Seq) was measured from mouse embryonic stem cells and mouse embriod bodies, in WT and Mettl3-KO cell lines.
Stem cells. m6A mRNA methylation facilitates resolution of naïve pluripotency toward differentiation.
No sample metadata fields
View SamplesThe coupling between cell-cycle exit and onset of differentiation is a common feature throughout the developing nervous system, but the mechanisms that link these processes are mostly unknown. Although the transcription factor Pax6 was implicated in both proliferation and differentiation of multiple regions within the CNS, its contribution to the transition between these successive states remains elusive. To gain insight into the role of Pax6 during the transition from proliferating progenitors to differentiating precursors, we investigated cell-cycle and transcriptomic changes occurring in Pax6- retinal progenitor cells (RPCs). Our analyses revealed a unique cell-cycle phenotype of the Pax6-deficient RPCs, which included a reduced number of cells in the S phase, an increased number of cells exiting the cell cycle, and delayed differentiation kinetics of Pax6- precursors. These alterations were accompanied by co-expression of factors that promote (Ccnd1, Ccnd2, Ccnd3) and inhibit (P27kip1 and P27kip2) the cell cycle. Further characterization of the changes in transcription profile of the Pax6-deficient RPCs revealed abrogated expression of multiple factors which are known to be involved in regulating proliferation of RPCs, including the transcription factors Vsx2, Nr2e1, Plagl1 and Hedgehog signaling. These findings provide novel insight into the molecular mechanism mediating the pleiotropic activity of Pax6 in RPCs. The results further suggest that rather than conveying a linear effect on RPCs, such as promoting their proliferation and inhibiting their differentiation, Pax6 regulates multiple transcriptional networks which function simultaneously, thereby conferring the capacity to proliferate, assume multiple cell fates and execute the differentiation program into retinal lineages.
Pax6 is required for normal cell-cycle exit and the differentiation kinetics of retinal progenitor cells.
Specimen part
View SamplesMicroarray data allowed detection of genes that are highly expressed in the pineal gland.
A new cis-acting regulatory element driving gene expression in the zebrafish pineal gland.
Sex
View SamplesOocyte quality is a well- established determinant of embryonic fate. However, the molecular participants and biological markers that affect and predict adequate embryonic development are largely elusive. We have previously reported that oocyte- directed Connexin 43 (Cx43) depletion leads to embryo implantation defects, although both the morphology of the oocyte and processes presiding embryo implantation appear to undergo normally. In the context of previous data determining Cx43 indispensability to oocyte and embryonic development, we show here that the timing of Cx43 depletion from the oocyte and the ovarian follicle is crucial in determining the severity of subsequent embryonic defects. Specifically, we show that the implantation defects of blastocysts resulting from oocyte- directed Cx43- depleted follicles (depletion occurs at day 3 postnatal), is not due to maternal luteal insufficiency but rather depends solely on the defective blastocysts. Gene expression microarray analysis revealed global defects in the expression of ribosomal proteins, translation initiation factors and other genes associated with cellular biosynthetic and metabolic processes in these defective oocytes and specifically blastocysts. We therefore propose that timely expression of Cx43 in the oocyte and ovarian follicles is a major determinant of oocyte developmental competence, by determining the ability of the resulting blastocyst to facilitate biomass expansion and undergo adequate embryo implantation
Blastocyst implantation failure relates to impaired translational machinery gene expression.
Specimen part
View SamplesThe cellular response to DNA damage is vital for maintaining genomic stability and preventing undue cell death or cancer formation. The DNA damage response (DDR), most robustly mobilized by double-strand breaks (DSBs), rapidly activates an extensive signaling network that affects numerous cellular systems, leading to cell survival or programmed cell death. A major component of the DDR is the widespread modulation of gene expression. We analyzed transcriptional responses to ionizing radiation (IR) in 5 human cell lines to elucidate the scope of this response and identify its gene targets. According to the mRNA expression profiles most of the responses were cell line-specific. Data analysis identified significant enrichment for p53 target genes and cell cycle-related pathways among groups of up-regulated and down-regulated genes, respectively.
Transcriptional modulation induced by ionizing radiation: p53 remains a central player.
Cell line, Time
View SamplesPolyamines are absolutely required for cell growth and proliferation. While polyamine depletion results in reversible cell cycle arrest, the actual mechanism of growth inhibition is still obscure.
Expression profiling and biochemical analysis suggest stress response as a potential mechanism inhibiting proliferation of polyamine-depleted cells.
Specimen part, Cell line
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