Mammalia
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA280453 | ENA |
REPOSITORIES: ENA
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Project description:Platelet activation is the key event triggering thrombus formation in physiological and pathological conditions, such as acute coronary syndromes. Current therapies using antiaggregants still fail to prevent thrombotic coronary events in a significant number of patients, indicating that the mechanisms modulating platelet response during activation need to be clarified. The evidence that platelets are capable of de novo protein synthesis in response to stimuli raised the issue of how the activity of megakaryocyte-derived mRNAs is regulated in these anucleate cell fragments. We applied a combined multi-omics approach to investigate this phenomenon in platelets from healthy donors activated in vitro with Collagen or Thrombin Receptor Activating Peptide. Combining HiRIEF LC-MS to transcriptome analysis by RNA-Seq allowed platelet proteome characterization at deep coverage, revealing a significant effect of either stimulus on proteome composition. In silico intron retention analysis was then applied to search for splicing events induced by platelet activation, coupled to unbiased proteogenomics, to correlate intron retention in resting platelets to intron removal by RNA splicing during activation. This allowed identification of a set of transcripts, specifically involved in platelet shape changes, showing reduced intron retention and high peptide representation at exon-exon junctions in activated vs resting platelets. These results indicate that RNA splicing events takes place in platelets during activation and that pre-mRNA maturation of specific transcripts is part of the activation cascade and could therefore provide novel molecular markers of platelet activation status in acute coronary syndromes and other pathological conditions.
2018-01-15 | E-MTAB-6148 | biostudies-arrayexpress
Project description:RNA splicing, the process of intron removal from pre-mRNA, is essential for the regulation of gene expression. It is controlled by the spliceosome, a megadalton RNA-protein complex that assembles de novo on each pre-mRNA intron via an ordered assembly of intermediate complexes. Spliceosome activation is a major control step requiring dramatic protein and RNA rearrangements leading to a catalytically active complex. Splicing factor 3B subunit 1 (SF3B1) protein, a subunit of the U2 snRNP, is phosphorylated during spliceosome activation, but the responsible kinase has not been identified. Here we show that cyclin-dependent kinase 11 (CDK11) associates with SF3B1 and phosphorylates threonine residues at its N-terminus during spliceosome activation. The phosphorylation is important for association of SF3B1 with U5 and U6 snRNAs in spliceosome activated Bact complex and it can be blocked by OTS964, a potent and selective inhibitor of CDK11. CDK11 inhibition prevents spliceosomal transition from the precatalytic complex B to the activated complex Bact and leads to widespread intron retention and accumulation of non-functional spliceosomes on pre-mRNAs and chromatin. We characterize OTS964 as a quality chemical biology probe for CDK11 and demonstrate a central role of CDK11 in spliceosome assembly and splicing regulation.
2022-07-09 | MSV000089855 | MassIVE
Project description:Exon-intron circRNA (EIciRNA) is a subclass of backsplicing-generated circRNAs featured with intron retention, among which some play roles in transcriptional regulation. We aim to characterize EIciRNAs by developing pipeline and investigate the factors involved in regulating EIciRNA biogenesis using CRISPR-Cas9 screen, as well as the physiology functions of EIciRNAs during neuronal differentiation.
2024-03-04 | GSE253233 | GEO
Project description:Exon-intron circRNA (EIciRNA) is a subclass of backsplicing-generated circRNAs featured with intron retention, among which some play roles in transcriptional regulation. We aim to characterize EIciRNAs by developing pipeline and investigate the factors involved in regulating EIciRNA biogenesis using CRISPR-Cas9 screen, as well as the physiology functions of EIciRNAs during neuronal differentiation.
2024-03-04 | GSE241682 | GEO
Project description:Exon-intron circRNA (EIciRNA) is a subclass of backsplicing-generated circRNAs featured with intron retention, among which some play roles in transcriptional regulation. We aim to characterize EIciRNAs by developing pipeline and investigate the factors involved in regulating EIciRNA biogenesis using CRISPR-Cas9 screen, as well as the physiology functions of EIciRNAs during neuronal differentiation.
2024-03-04 | GSE241679 | GEO
Project description:<p>The etiologies of primary immunodeficiencies often yield novel insights about the immune system. Although a genetic etiology has been suspected for patients with abnormally low CD4+ T cells in the absence of HIV infection or any known causes of lymphopenia, no genetic mutation has been described to date for any case of primary CD4 lymphopenia. In this study, we characterized a non-consanguineous family with two non-HIV infected boys exhibiting an inverted CD4 to CD8 T cell ratio and a history of recurrent chronic viral infections since birth. Consistent with a decreased thymic output of CD4+ T cells, the percentage of CD31+ cells in the CD4+ naive population of these patients was decreased. In addition, the activation of T cells was significantly impaired in the patient upon TCR stimulation. Given the mother's T cells show completely skewed X chromosome inactivation, we suspected that the nature of this disease is X-linked. We performed X-chromosome exon-capture targeted single-end Solexa sequencing on two brothers and the mother and found a 10 base pair deletion at an intron-exon junction of Magnesium Transporter 1 (MAGT1), a Mg<sup>2+</sup> specific transporter. We confirmed that this deletion leads to altered splicing, frameshift, early termination of the mRNA, and deficient protein expression in the lymphocytes of the two patients. Moreover, knockdown of this transporter in T cells isolated from healthy donors can recapitulate the observed T cell activation defect while its ectopic expression in the patients' lymphocytes can restore T cell stimulation. Our discovery highlights the significance of this transporter to T cell function.</p>
| phs000365 | dbGaP
Project description:Splicing factor SF3B1 is frequently mutated in chronic lymphocytic leukemia (CLL) patients and has been suggested as a potential therapeutic target. In this study, we performed RNA-seq analysis to evaluate the global impact of SF3B1 modulator sudemycin D6 (SD6) on alternative splicing. Our analysis revealed significant increases in global intron-retention in SD6-treated CLL cells. Pathway analysis of the genes associated with increased intron-retention suggested that B-cell receptor (BCR), protein ubiquitination, and PI3K signaling pathways were among the top canonical pathways being affected by SD6. The increases in intron-retention were inversely correlated with deceases in mRNA and protein levels of the affected BCR/PI3K pathway molecules such as BLNK, BTK, AKT1, PLCγ2 and PI3Kδ. SD6 also induced a time-dependent exon-skipping event in mRNA of MCL1 and resulted in significant down-regulation of another anti-apoptotic gene TRAF1, which may contribute to the SD6-induced apoptosis. Finally, SD6 can overcome the pro-survival and pro-growth signals and synergize with ibrutinib, idelalisib and venetoclax to induce apoptosis in primary CLL cells co-cultured with bone marrow stromal cells and in the presence of T-cell-derived cytokines. Cumulatively, these results provide a strong rationale for future clinical development of spliceosome modulators and combinatory therapies based on spliceosome modulators in CLL.
2018-05-17 | GSE114514 | GEO
Project description:Calcium Homeostasis Endoplasmic Reticulum Protein (CHERP) is co-localized with inositol 1,4,5-trisphosphate receptor (IP3R) in the endoplasmic reticulum or peri-nuclear part, and has been considered to have a role in intracellular calcium signaling. Recently, it has recognized that CHERP structurally carries nuclear localization signal and arginine/serine-dipeptide repeats like domain, and interacts with spliceosome. In this study, we showed that poly (A)+ RNA was accumulated in the nucleus on CHERP depletion. Using the global analysis, CHERP regulated alternative mRNA splicing events through the interaction with U2 snRNP and U2 snRNP related proteins. Our analysis indicated that intron retention was most frequently observed among five alternative splicing patterns in accordance with the accumulation of poly (A)+ RNA in the nucleus. Further, intron retention and cassette exon choice were influenced by the strength of 5’ or 3’ splice site, GC content, or intron length. In addition, CHERP depletion induced the abnormality of cell cycle progression at M phase and cell division. These results suggested that CHERP was involved in the regulation of alternative splicing.
2022-06-19 | GSE193399 | GEO
Project description:Primary T cell activation involves the integration of three distinct signals delivered in sequence: 1) antigen recognition, 2) costimulation, and 3) cytokine-mediated differentiation and expansion. Strong immunostimulatory events such as immunotherapy or infection induce profound cytokine release causing bystander T cell activation, thereby increasing the potential for autoreactivity and need for control. We show that during strong stimulation, a profound suppression of primary CD4+ T cell-mediated immune responses ensued and was observed across preclinical models and patients undergoing high-dose interleukin-2 (IL-2) therapy. This suppression targeted naïve CD4+ but not CD8+ T cells and was mediated through transient suppressor of cytokine signaling-3 (SOCS3) inhibition of the STAT5b transcription factor signaling pathway. These events resulted in complete paralysis of primary CD4+ T cell activation affecting memory generation, induction of autoimmunity, as well as impaired viral clearance. These data highlight the critical regulation of naïve CD4+ T cells during inflammatory conditions.
2015-07-21 | GSE71124 | GEO
Project description:Exposure to certain stresses leads to readthrough transcription downstream of gene ends. Here we found that this phenomenon impacts the expression of genes located downstream to readthrough genes, whereby readthrough transcription proceeds into downstream genes, termed read-in genes. Using polyA-selected RNA-seq data from mouse fibroblasts, we identified widespread read-in in heat shock, oxidative and osmotic stress conditions. Read-in genes share distinctive genomic characteristics; they are extremely short, mainly due to less, shorter, introns, and they are highly GC rich. Furthermore, using ribosome footprint profiling we found that the translation of genes with high degrees of read-in is significantly reduced. Strikingly, read-in genes show extremely high levels of intron retention during stress, mostly in their first intron. While read-in genes share features that are generally associated with increased likelihood of intron retention, such as short introns and high GC content, intron retention in read-in genes during stress exceeds greatly beyond what is expected given their genomic properties. Finally, we found that first introns in read-in genes have weaker 5’ and 3’ splice sites. Our data portray a relationship between read-in and intron retention, suggesting it may have co-evolved to facilitate reduced translation of read-in genes during stress.
2022-10-27 | GSE197536 | GEO