UC pouchitis is a potential model of UC. We prospectively examined the pouch transcriptomes of UC and familial adenomatous polyposis (FAP) IPAA patients to unveil molecular mechanisms of UC pouchitis susceptibility. Methods: Total RNA was isolated using the AllPrep DNA/RNA Mini Kit (QIAGEN, Cat No. 8020). RNA quality was evaluated using Bioanalyzer (Agilent, Santa Clara, CA). All RNA samples displayed RNA Integrity Number (RIN) >7. RNAseq including cDNA library preparation was processed at the Genomics Core Facility of University of Chicago (https://fgf.uchicago.edu/). Total RNA in the amount of 100-500µg per sample was depleted of ribosomal RNA using the Ribo-Zero kit (Epicentre, Madison, WI). The directional (first strand) cDNA libraries were prepared following the guide of TruSeq Stranded Total RNA Sample Preparation kit. Results: Unlike FAP patients, UC subjects exhibited a large set of differentially expressed genes (DEGs) between pouch and pre-pouch mucosa as early as 4 months after pouch functionalization. Functional pathway analysis of DEGs in UC pouch revealed: (1) Gain of colon-associated gene expressions and loss of ileum associated gene expressions, (2) enhanced state of immune/inflammatory response, and (3) suppressed xenobiotic, lipid, and bile acid metabolic pathways. These changes were corroborated upon reanalysis of a published larger cross-sectional study of UC and FAP patients. Moreover, >70% of DEGs mapped to published IBD and normal colonic microarray datasets displayed directional changes consistent with active UC, but not Crohn''s disease. Conclusions: UC patients exhibit a unique transcriptomic response to ileal pouch creation that can be observed well before disease. The transcriptome alterations provide insights into pouchitis Overall design: Seventeen patients with UC and four patients with FAP were recruited at the University of Chicago and the Mayo Clinic Rochester. All patients underwent a total proctocolectomy with ileal pouch anal anastomosis (IPAA) as a standard of care. UC patients underwent a pouchoscopy for biopsy of the pre-pouch ileum and pouch at 4 months, 8 months, and 12 months after ileostomy closure. None of these patients had pouchitis.
Early Transcriptomic Changes in the Ileal Pouch Provide Insight into the Molecular Pathogenesis of Pouchitis and Ulcerative Colitis.
Sex, Age, Specimen part, Disease, Race, Subject
View SamplesGut dysbiosis and host genetics are implicated as causative factors in inflammatory bowel disease, yet mechanistic insights are lacking. Longitudinal analysis of ulcerative colitis patients following total colectomy with ileal anal anastomosis (IPAA) where >50% develop pouchitis, offers a unique setting to examine cause vs. effect. To recapitulate human IPAA, we employed a mouse model of surgically-created blind self-filling (SFL) and self-emptying (SEL) ileal loops. SFL exhibit fecal stasis due to directional peristalsis motility oriented towards away from the loop end, whereas SEL remain empty. In wild type mice, SFL, but not SEL, develop pouch-like microbial communities without accompanying active inflammation. However, in genetically susceptible IL-10-/- deficient mice, SFL, but not SEL, exhibit severe inflammation and mucosal transcriptomes resembling human pouchitis. Germ-free IL10-/- mice conventionalized with wild type SFL, but not SEL, microbiota, develop severe colitis. These data demonstrate an essential role for fecal stasis, gut dysbiosis, and genetic susceptibility and offer insights into human pouchitis and ulcerative colitis.
Insights into the pathogenesis of ulcerative colitis from a murine model of stasis-induced dysbiosis, colonic metaplasia, and genetic susceptibility.
Specimen part
View SamplesPlant immune responses to pathogen attack involve various defense mechanisms and among them, the Hypersensitive Response (HR), a form of programmed cell death occurring at invasion sites. AtMYB30, a transcription factor acts as a positive regulator of a cell death pathway conditioning the HR.
A MYB transcription factor regulates very-long-chain fatty acid biosynthesis for activation of the hypersensitive cell death response in Arabidopsis.
No sample metadata fields
View SamplesNeuroprotective therapies for retinal degeneration may be used to rescue retinal cells and preserve vision. Hypoxic preconditioning stabilizes the transcription factor HIF-1 in the retina and strongly protects photoreceptors in an animal model of light-induced retinal degeneration.
Analysis of the retinal gene expression profile after hypoxic preconditioning identifies candidate genes for neuroprotection.
No sample metadata fields
View SamplesAlveolar soft-part sarcoma (ASPS) is an extremely rare, highly vascular soft tissue sarcoma affecting predominantly adolescents and young adults. In an attempt to gain insight into the pathobiology of this enigmatic tumor, we performed the first genome-wide gene expression profiling study.
Gene expression profiling of alveolar soft-part sarcoma (ASPS).
No sample metadata fields
View SamplesGene expression from bone-marrow drived macrophages of WT and SREBP-1a deficient mice
Linking lipid metabolism to the innate immune response in macrophages through sterol regulatory element binding protein-1a.
No sample metadata fields
View SamplesThe infant leukemia-associated gene, Ott1(Rbm15), has broad regulatory effects within the murine hematopoiesis. However, germline Ott1 deletion results in fetal demise prior to E10.5, indicating additional developmental requirements for Ott1. The spen gene family, to which Ott1 belongs, has a transcriptional activation/repression domain and RNA recognition motifs, and in Drosophila has a significant role in the development of the head and thorax. Early Ott1-deficient embryos show growth retardation and incomplete closure of the notochord. Further analysis demonstrated placental defects in the spongiotrophoblast and syncytiotrophoblast layers, resulting in an arrest of vascular branching morphogenesis. Rescue of the placental defect using a conditional allele with a trophoblast-sparing cre transgene allowed embryos to form a normal placenta and survive gestation. This result shows that the process of vascular branching morphogenesis in Ott1-deficient animals is regulated by the trophoblast compartment rather than the fetal vasculature. Mice surviving to term manifested hyposplenia and abnormal cardiac development. Analysis of global gene expression of Ott1-deficient embryonic hearts shows enrichment of hypoxia-related genes and significant alteration of several candidate genes critical for cardiac development. Thus, Ott1-dependent pathways in addition to being implicated in leukemogenesis, may also be important in the pathogenesis of placental insufficiency and cardiac malformations.
Ott1 (Rbm15) is essential for placental vascular branching morphogenesis and embryonic development of the heart and spleen.
No sample metadata fields
View SamplesThe infant leukemia-associated gene, Ott1 (Rbm15), has broad regulatory effects on embryonic development and hematopoiesis. Embryonic deletion of Ott1 results in defects to the placenta, spleen and heart. Conditional deletion within the adult hematopoietic compartment demonstrates a requirement in pre-B development and inhibitory roles in myeloid progenitor and megakaryocyte populations. Ott1-deleted bone marrow has an expansion of the Lin- Sca-1+ c-Kit+ (LSK) population which includes the hematopoietic stem cell (HSC) population. Functional HSC testing through competitive repopulation of irradiated recipients demonstrated however, a severe defect in Ott1-deficient HSCs, despite adequate numbers of immunophenotypically identified long term HSCs. Although mice deleted in situ for Ott1 are able to maintain hematopoiesis in steady state over a normal lifetime, but when subjected to proliferative stress, the HSC population loses the self-renewing, G0 fraction and undergoes bone marrow failure.
Hematopoietic stem cells lacking Ott1 display aspects associated with aging and are unable to maintain quiescence during proliferative stress.
Specimen part
View SamplesSalmonella enterica serotype Typhimurium causes an acute inflammatory reaction in the cecum of streptomycin pre-treated mice. We determined global changes in gene expression elicited by serotype Typhimurium in the cecal mucosa. The gene expression profile was dominated by T cell derived cytokines and genes whose expression is known to be induced by these cytokines. Markedly increased mRNA levels of interferon (IFN-gamma), interleukin-22 (IL-22) and IL-17 were detected by quantitative real-time PCR. Furthermore, mRNA levels of genes whose expression is induced by IFN-gamma, IL-22 or IL-17, including macrophage inflammatory protein 2 (MIP-2), inducible nitric oxide synthase (Nos2), lipocalin-2, MIP-1alpha, MIP-1beta, and keratinocyte-derived cytokine (KC), were also markedly increased. To assess the importance of T cells in orchestrating this pro-inflammatory gene expression profile, we depleted T cells using a monoclonal antibody prior to investigating cecal inflammation caused by serotype Typhimurium in streptomycin pre-treated mice. Depletion of CD3+ T cells resulted in a dramatic reduction in gross pathology, a significantly reduced recruitment of neutrophils and a marked reduction in mRNA levels of IFN-gamma, IL-22, IL-17, iNOS, lipocalin-2 and KC. Our results suggest that T cells play an important role in amplifying inflammatory responses induced by serotype Typhimurium in the cecal mucosa.
T cells help to amplify inflammatory responses induced by Salmonella enterica serotype Typhimurium in the intestinal mucosa.
No sample metadata fields
View SamplesC/EBP (CCAAT enhancer binding protein) is a transcription factor that plays a crucial role in survival and transformation of ALK+ anaplastic large cell lymphoma (ALCL). The aim of this study was to identify the downstream targets of C/EBP responsible for ALK-mediated oncogenesis. C/EBP was knocked down in ALK+ ALCL cell lines with a C/EBP-shRNA, followed by gene expression profiling (GEP). GEP analysis revealed a reproducible signature of genes that were significantly regulated by C/EBP. Classification into biological categories revealed overrepresentation of genes involved in the immune response, apoptosis and cell proliferation. Transcriptional regulation by C/EBP was found in 6 of 11 (BCL2A1, G0S2, TRIB1, S100A9, DDX21 and DDIT4) genes investigated by chromatin immunoprecipitation. We demonstrated that BCL2A1, G0S2 and DDX21 play a crucial role in survival and proliferation of ALK+ ALCL cells. DDX21, a gene involved in rRNA biogenesis, was found differentially overexpressed in primary ALK+ ALCL cases. All three candidate genes were validated in primary ALCL cases by either immunohistochemistry or RT-qPCR. In conclusion, we identified and validated several key C/EBP-regulated genes with major impact on survival and cell growth in ALK+ ALCL, supporting the central role of C/EBP in ALK-mediated oncogenesis.
Identification of C/EBPβ target genes in ALK+ anaplastic large cell lymphoma (ALCL) by gene expression profiling and chromatin immunoprecipitation.
Sex, Cell line
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