How G4C2 repeat expansions in C9orf72 cause frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) is not understood. Here, we report the first mouse model to express poly(PR), a dipeptide repeat protein synthesized from expanded G4C2 repeats. Expression of GFP-(PR)50 throughout the mouse brain yielded progressive brain atrophy, neuron5 loss, loss of poly(PR)-positive cells and gliosis, culminating in motor and memory impairments. We found that poly(PR) bound DNA, localized to heterochromatin, and caused abnormal histone methylation, lamin invaginations, decreases in HP1a expression, and disruptions of HP1a liquid phases. These aberrations of histone methylation, lamins and HP1a, which regulate heterochromatin structure and gene expression, were accompanied by repetitive element10 expression and double-stranded RNA accumulation. Thus, we uncover new mechanisms by which poly(PR) contributes to c9FTD/ALS pathogenesis. Overall design: Examination of transcriptome profiles using RNA-seq on 3 month old mice expressing PR and GR polypetides with an AAV expression vector. The Poly(PR) analysis consisted of 7 mice expressing AAV-GFP-(PR)50 and 4 AAV-GFP harvest-matched controls. The Poly(GR) analysis consisted of 4 mice expressing AAV-GFP-(GR)100 and 4 AAV-GFP harvest-matched controls.
Heterochromatin anomalies and double-stranded RNA accumulation underlie <i>C9orf72</i> poly(PR) toxicity.
Sex, Age, Cell line, Subject
View SamplesThe role of androgen in breast cancer development is not fully understood although androgen receptors (AR) have been identified in breast cancer clinical samples and cell lines. However the whole spectra of androgen actions cannot be accounted to the classic AR mode of action and the possible existence of a cell surface AR has been suggested. Indeed androgens like all steroids have been reported to trigger membrane initiated signaling activity and exert specific actions. Androgens acting on the membrane can rapidly activate kinase signaling pathways and ultimately could affect gene expression. However, the molecular nature of membrane androgen binding sites represents another major persisting question. In the present study, we investigated early transcriptional effects of testosterone and the impermeable testosterone-BSA conjugate, in two breast cancer cell lines, in an attempt to decipher specific genes modified in each case, providing evidences about specific membrane initiating actions. Our data indicate that the two agents tested affect the expression of several genes. A group of genes were commonly affected while others were uniquely modified by each agent. In MDA-MB-231 cells, that are AR negative, the majority of genes affected by testosterone were also affected by testosterone-BSA indicating a membrane action. Subsequent analysis revealed that the two agents trigger different molecular pathways and cellular/molecular functions, suggestive of a molecular heterogeneity of membrane and intracellular AR. In addition, the phenotypic interactions of membrane-acting androgen with growth factor were verified at the transcriptomic level. Finally an interesting interplay between membrane-acting androgen with inflammation-related molecules, with potential clinical implications was revealed.
Conjugated and non-conjugated androgens differentially modulate specific early gene transcription in breast cancer in a cell-specific manner.
Specimen part, Cell line
View SamplesIn gastrulation, distinct progenitor cell populations are induced and sorted into the three germ layers ectoderm, mesoderm and endoderm. In order to identify genes involved in germ layer specification and morphogenesis, we identified genes differentially expressed between ectodermal and mesendodermal progenitor cells. To do so, we first generated highly enriched pools of ectodermal and mesendodermal progenitor cells. Mesendodermal cells were generated by over-expressing the Nodal signal Cyclops in wild type embryos and ectodermal cells were taken from mz-one-eyed-pinhead (oep) mutant embryos. We then compared the transcriptome of ectodermal versus mesendodermal cells taken from embryos at 7 hours post fertilization (hpf). In wild type embryos at this stage (70% epiboly), the first ectodermal and mesendodermal progenitor cells have already been sorted into their respective germ layers and ingression of mesendodermal progenitors is still ongoing.
Identification of regulators of germ layer morphogenesis using proteomics in zebrafish.
Age, Specimen part, Subject, Time
View SamplesOrganoids derived from human pluripotent stem cells recapitulate the early three-dimensional organization of human brain, but whether they establish the epigenomic and transcriptional programs essential for brain development is unknown. We compared epigenomic and gene regulatory features in cerebral organoids and human fetal brain, using genome-wide, base resolution DNA methylome and transcriptome sequencing. Transcriptomic dynamics in organoids faithfully modeled gene expression trajectories in early-to-mid human fetal brains. We found that early non-CG methylation accumulation at super-enhancers in both fetal brain and organoids marks forthcoming transcriptional repression in the fully developed brain. 74% of 35,627 demethylated regions identified during organoid differentiation overlapped with fetal brain regulatory elements. Interestingly, pericentromeric repeats showed widespread demethylation in multiple types of in vitro human neural differentiation models but not in fetal brain. Our study reveals that organoids recapitulate many epigenomic features of mid-fetal human brain and also identified novel non-CG methylation signatures of brain development. Overall design: MethylC-seq and RNA-seq of Cerebral Organoids differentiation
Cerebral Organoids Recapitulate Epigenomic Signatures of the Human Fetal Brain.
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Whole transcriptome analysis of the ERα synthetic fragment P295-T311 (ERα17p) identifies specific ERα-isoform (ERα, ERα36)-dependent and -independent actions in breast cancer cells.
Cell line
View SamplesER17p is a synthetic peptide corresponding to the sequence P295LMIKRSKKNSLALSLT311 of the estrogen receptor alpha (ER) and initially synthesized to mimic its calmodulin binding site. ER17p was subsequently found to elicit estrogenic responses in E2-deprived ER-positive breast cancer cells, increasing proliferation and E2-dependent gene transcription. Surprisingly, in E2-supplemented media, ER17p induced apoptosis and modified the actin network, influencing thereby cell motility. Here, we report that ER17p induces a massive early (3h) transcriptional activity in breast cancer cell lines SKBR3). Remarkably, about 75% of the significantly modified transcripts were also modified by E2, confirming the pro-estrogenic profile of ER17p. The different ER spectra of the used cell lines allowed us to extract a specific ER17p signature related to ER and its variant ER36. With respect to ER, the peptide activates nuclear (cell cycle, cell proliferation, nucleic acid and protein synthesis) and extranuclear signaling pathways. In contrast, through ER36 it exerts inhibitory events on inflammation and cell cycle and inhibition of EGFR signaling. This is the first work reporting ER36 specific transcriptional effects. The fact that a number ER17p-induced transcripts is different from those activated by E2 revealed that the apoptosis and actin modifying effects of ER17p are independent from the ER-related actions of the peptide.
Whole transcriptome analysis of the ERα synthetic fragment P295-T311 (ERα17p) identifies specific ERα-isoform (ERα, ERα36)-dependent and -independent actions in breast cancer cells.
Cell line
View SamplesER17p is a synthetic peptide corresponding to the sequence P295LMIKRSKKNSLALSLT311 of the estrogen receptor alpha (ER) and initially synthesized to mimic its calmodulin binding site. ER17p was subsequently found to elicit estrogenic responses in E2-deprived ER-positive breast cancer cells, increasing proliferation and E2-dependent gene transcription. Surprisingly, in E2-supplemented media, ER17p induced apoptosis and modified the actin network, influencing thereby cell motility. Here, we report that ER17p induces a massive early (3h) transcriptional activity in breast cancer cell line MDA-MB-231.
Whole transcriptome analysis of the ERα synthetic fragment P295-T311 (ERα17p) identifies specific ERα-isoform (ERα, ERα36)-dependent and -independent actions in breast cancer cells.
Cell line
View SamplesER17p is a synthetic peptide corresponding to the sequence P295LMIKRSKKNSLALSLT311 of the estrogen receptor alpha (ER) and initially synthesized to mimic its calmodulin binding site. ER17p was subsequently found to elicit estrogenic responses in E2-deprived ER-positive breast cancer cells, increasing proliferation and E2-dependent gene transcription. Surprisingly, in E2-supplemented media, ER17p induced apoptosis and modified the actin network, influencing thereby cell motility. Here, we report that ER17p induces a massive early (3h) transcriptional activity in breast cancer cell line T47D.
Whole transcriptome analysis of the ERα synthetic fragment P295-T311 (ERα17p) identifies specific ERα-isoform (ERα, ERα36)-dependent and -independent actions in breast cancer cells.
Cell line
View SamplesQuercetin is a flavonol modifying numerous cell processes with potent antiproliferative effects on cancer cell-lines. The aim of this study was to explore by gene-array analysis the effect of quercetin on cancer-related gene expression in HepG2 cells, followed by verification with RT-PCR and analysis of the expected phenotypic changes (migration, cell cycle, cell proliferation). Quercetin induces significant changes on cell-adhesion related genes, leading to reduced migratory capacity and disorganization of the actin cytoskeleton. Several genes related to DNA functions, cellular metabolism and signal-transducer activities were also modified, while an early effect on Gprotein related cascades possibly via protease-activated receptor 2 and phospholipase C-1 was identified. Cyclin-D associated events in G1 and ubiquitin-dependent degradation of cyclin-D1 were also affected, resulting in cell-cycle arrest without activation of apoptosis pathways. In conclusion quercetin (3M) exerts its cellular effects by modifying numerous genes related to mechanisms involved in cancer initiation and promotion.
Quercetin accumulates in nuclear structures and triggers specific gene expression in epithelial cells.
Cell line
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Early membrane initiated transcriptional effects of estrogens in breast cancer cells: First pharmacological evidence for a novel membrane estrogen receptor element (ERx).
Specimen part, Cell line
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