Adjacent alternative 3’ splice sites, those separated by =18nt, provide a unique problem in the study of alternative splicing regulation; there is overlap of the cis-elements that define the adjacent sites. Identification of the intron''s 3'' end depends upon sequence elements that define the branchpoint, polypyrimidine tract and terminal AG dinucleotide. Starting with RNA-seq data from germline-enriched and somatic cell-enriched C. elegans samples, we identify hundreds of introns with adjacent alternative 3’ splice sites. We identify 203 events that undergo tissue-specific alternative splicing. For these, the regulation is mono-directional, with somatic cells preferring to splice at the distal 3'' splice site and germline cells showing a distinct shift towards usage of the adjacent proximal 3'' splice site. Splicing patterns in somatic cells follow consensus rules of 3’ splice site definition, using sites with a short stretch of pyrimidines and an AG dinucleotide. Splicing in germline cells occurs at proximal 3'' splice sites that frequently lack a polypyrimidine tract or, occasionally, the AG dinucleotide. We provide evidence that use of germline-specific proximal 3'' splice sites is conserved across Caenorhabditis species. We propose that divergent mechanisms exist between germline and somatic cells in determining an intron terminus at adjacent alternative 3’ splice sites. Overall design: Examination of alternative splicing changes between germline- and somatic-cell enriched samples as well as nonsense-mediated decay mutants.
Coordinated tissue-specific regulation of adjacent alternative 3' splice sites in C. elegans.
Specimen part, Cell line, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Intrinsic self-DNA triggers inflammatory disease dependent on STING.
Specimen part
View SamplesInflammatory diseases such as Aicardi-Goutieres Syndrome (AGS) and severe systemic lupus erythematosus (SLE) are generally lethal disorders that have been traced to defects in the exonuclease Trex1 (DNAseIII). Mice lacking Trex1 similarly die at an early age through comparable symptoms, including inflammatory myocarditis, through chronic activation of the STING (stimulator of interferon genes) pathway. Here we demonstrate that phagocytes rather than myocytes are predominantly responsible for causing inflammation, an outcome that could be alleviated following adoptive transfer of normal bone marrow into Trex1-/- mice. Trex1-/- macrophages did not exhibit significant augmented ability to produce pro-inflammatory cytokines compared to normal macrophages following exposure to STING-dependent activators, but rather appeared chronically stimulated by genomic DNA. These results shed molecular insight into inflammation and provide concepts for the design of new therapies.
Intrinsic self-DNA triggers inflammatory disease dependent on STING.
Specimen part
View SamplesActivation of the STING (Stimulator of Interferon Genes) pathway by microbial or self-DNA, as well as cyclic di nucleotides (CDN), results in the induction of numerous genes that suppress pathogen replication and facilitate adaptive immunity. However, sustained gene transcription is rigidly prevented to avoid lethal STING-dependent pro-inflammatory disease by mechanisms that remain unknown. We demonstrate here that after autophagy-dependent STING delivery of TBK1 (TANK-binding kinase 1) to endosomal/lysosomal compartments and activation of transcription factors IRF3 (interferon regulatory factors 3) and NF-B (nuclear factor kappa beta), that STING is subsequently phosphorylated by serine/threonine UNC-51-like kinase (ULK1/ATG1) and IRF3 function is suppressed. ULK1 activation occurred following disassociation from its repressor adenine monophosphate activated protein kinase (AMPK), and was elicited by CDNS generated by the cGAMP synthase, cGAS. Thus, while CDNs may initially facilitate STING function, they subsequently trigger negative-feedback control of STING activity, thus preventing the persistent transcription of innate immune genes.
Cyclic dinucleotides trigger ULK1 (ATG1) phosphorylation of STING to prevent sustained innate immune signaling.
Age, Specimen part, Treatment
View SamplesInflammatory diseases such as Aicardi-Goutieres Syndrome (AGS) and severe systemic lupus erythematosus (SLE) are generally lethal disorders that have been traced to defects in the exonuclease Trex1 (DNAseIII). Mice lacking Trex1 similarly die at an early age through comparable symptoms, including inflammatory myocarditis, through chronic activation of the STING (stimulator of interferon genes) pathway. Here we demonstrate that phagocytes rather than myocytes are predominantly responsible for causing inflammation, an outcome that could be alleviated following adoptive transfer of normal bone marrow into Trex1-/- mice. Trex1-/- macrophages did not exhibit significant augmented ability to produce pro-inflammatory cytokines compared to normal macrophages following exposure to STING-dependent activators, but rather appeared chronically stimulated by genomic DNA. These results shed molecular insight into inflammation and provide concepts for the design of new therapies.
Intrinsic self-DNA triggers inflammatory disease dependent on STING.
Specimen part
View SamplesPrevalence and severity of allergic diseases have increased worldwide. To date, respiratory allergy phenotypes are not fully characterized and, in addition, the mechanisms underlying sublingual immunotherapy (SLIT) are still unknown.
Exploring novel systemic biomarker approaches in grass-pollen sublingual immunotherapy using omics.
Specimen part, Treatment, Time
View SamplesIn obesity an increase in -cell mass occurs to cope with the rise in insulin demand. This -cell plasticity is essential to avoid the onset of hyperglycemia, although the molecular mechanisms that regulate this process remain unclear. This study analyzed the role of adipose tissue in the control of -cell replication. Using a diet-induced model of obesity, we obtained conditioned media from three different white adipose tissue depots. Only in the adipose tissue depot surrounding the pancreas did the diet induce changes that led to an increase in INS1E cells and the islet replication rate. To identify the factors responsible for this proliferative effect, adipose tissue gene expression analysis was conducted by microarrays and quantitative RT-PCR. Of all the differentially expressed proteins, only the secreted ones were studied. IGF binding protein 3 (Igfbp3) was identified as the candidate for this effect. Furthermore, in the conditioned media, although the blockage of IGFBP3 led to an increase in the proliferation rate, the blockage of IGF-I receptor decreased it. Taken together, these data show that obesity induces specific changes in the expression profile of the adipose tissue depot surrounding the pancreas, leading to a decrease in IGFBP3 secretion. This decrease acts in a paracrine manner, stimulating the -cell proliferation rate, probably through an IGF-I-dependent mechanism. This cross talk between the visceral-pancreatic adipose tissue and -cells is a novel mechanism that participates in the control of -cell plasticity. (Endocrinology 153: 177187, 2012)
Role of IGFBP-3 in the regulation of β-cell mass during obesity: adipose tissue/β-cell cross talk.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
STING-Dependent Signaling Underlies IL-10 Controlled Inflammatory Colitis.
Specimen part
View SamplesThat commensal bacteria can influence intestinal inflammation has been observed using other models of chronic colitis. Loss of IL-10, a major immunosuppressive cytokine, induces spontaneous colitis in mice. The incidence of spontaneous polyp formation in IL-10-deficient mice was also completely eliminated in the absence of STING
STING-Dependent Signaling Underlies IL-10 Controlled Inflammatory Colitis.
Specimen part
View SamplesMyD88 may play a direct role in STING-dependent signaling, or alternatively that STING-dependent pro-inflammatory cytokines may require downstream MyD88-dependent signaling to exert their effect.
STING-Dependent Signaling Underlies IL-10 Controlled Inflammatory Colitis.
Specimen part
View Samples