Project description:Purpose: RNAseq was used to look in donor allografts for genes encoding cytokine receptors specific to the cytokines identified to be upregulated in the blood of Orthotopic liver transplantation (OLT) receipients with ischemia reperfusion injury (IRI) Methods: Liver mRNA cytokine receptor profiles of allografts taken before and after transplant, demultiplexed with Illumina CASAVA, trimmed with Cutadapt, aligned to hg38 with STAR, counted with featureCounts Results: We identified expression of genes encoding 10 cognate receptors for the 14 potential cytokines found to be upregulated in IRI+ patients. Conclusion: Many of the cytokines that are upregulated in the blood of IRI+ OLT recipients have cognate receptors present in donor livers that could allow completed signaling pathways to occur
Project description:We have studied the genes activated in human liver transplantation to identify potential target genes for the prevention or treatment of related injuries. In a first protocol, in order to evaluate the effect of Ischemia-Reperfusion Injury (IRI) on gene expression profile, we compared gene expression levels in transplanted-reperfused livers versus basal values in donor livers, identifying 795 genes significantly modified in human liver after transplantation. Some genes are likely to be completely activated by IRI, as they are not expressed at all in basal livers. In a second protocol, in order to identify gene dysregulations already present in donor livers, which might affect gene expression profile after transplantation, gene expression evaluated in the first study was compared to control livers (espression data retrieved from ArrayExpress database). About 900 genes in donor livers are dysregulated if compared to the control condition. At least 400 of them remain dysregulated or become more and more dysregulated after transplantation. For the first protocol, two biopsies were collected from each liver: 1 biopsy before explantation from the donor, immediately after opening, before ice was applied, and 1 biopsy about 2-3 hours after liver reperfusion in the recipient organism. Gene expression of 5 transplanted livers was compared to that of 5 donor livers. In the second protocol gene expression both of transplanted and donor livers was compared to gene expression data from 5 control livers retrieved from ArrayExpress repository SAMPLE ID: E-AFMX-11. This dataset is part of the TransQST collection.
Project description:We have studied the genes activated in human liver transplantation to identify potential target genes for the prevention or treatment of related injuries. In a first protocol, in order to evaluate the effect of Ischemia-Reperfusion Injury (IRI) on gene expression profile, we compared gene expression levels in transplanted-reperfused livers versus basal values in donor livers, identifying 795 genes significantly modified in human liver after transplantation. Some genes are likely to be completely activated by IRI, as they are not expressed at all in basal livers. In a second protocol, in order to identify gene dysregulations already present in donor livers, which might affect gene expression profile after transplantation, gene expression evaluated in the first study was compared to control livers (espression data retrieved from ArrayExpress database). About 900 genes in donor livers are dysregulated if compared to the control condition. At least 400 of them remain dysregulated or become more and more dysregulated after transplantation.
Project description:Allogeneic T cell expansion is the primary determinant of graft-versus-host disease (GVHD), and current dogma dictates that this is driven by histocompatibility antigen disparities between donor and recipient. This paradigm represents a closed genetic system within which donor T cells interact with peptide-MHC complexes, though clonal interrogation remains challenging due to the sparseness of the T cell repertoire. We developed a Bayesian model using donor and recipient TCR frequencies in murine stem cell transplant systems to define limited common expansion of T cell clones across genetically identical donor-recipient pairs. A subset of donor CD4 T cell clonotypes differentially expanded in identical recipients and were microbiota dependent. Microbiota-specific T cells augmented GVHD lethality and could target microbial antigen presented by gastrointestinal epithelium during an alloreactive response. The microbiota thus serves as a source of cognate antigen that contributes to clonotypic T cell expansion and the induction of GVHD independent of donor-recipient genetics.
Project description:In DCD organ donation one of the significant problems for the organ is the inflammatory response due to ischaemiua reperfusion injury caused by warm ischaemia prior to retrieval followed by warm reoxygenation upon transplantation. We developed a model where a DCD kidney was retrieved and stoired overnight then the organ was surgically attached to the femoral artery of a recipient rat and blood flow restored for up to six hours to simulate early ischaemia reperfusion injury (IRI). The recipient rats consisted of a control group compared to groups recieveing either low molecular weight heparin or an anti-inflammatory peptide to assess their activity in ameliorating IRI. We used equimolar pooled RNA samples from each group to perform an exploratory microarray experiment. Donor kidneys were harvested and static cold stored in University of Wisconsin (UW) Solution overnight before being surgically connected to the femoral artery of a recipient rat to simulate transplantation and whole blood ischaemia reperfusion injury. The model was then used to test the anti-inflammatory properties of the glycosaminoglycan heparin and a peptide based upon the heparin binding domain of the pro-inflammatory chemokine CCL5. The treatments were delivered as a bolus in normal saline and control recipients were given normal saline as a control. The kidneys underwent perfusion by normal blood flow for a period of up to six hours after which the recipient was euthanased and the donor kidney was removed. Half of the donor kidney was used to extract RNA and half taken for immunohistochemical analysis. The RNA was extracted using the Tri reagent and stored in RNA Later. The qualitative best three RNAs from each group were quantified by fluorimetry and mixed in an equimolar manner and used for microarray analysis.
Project description:INTRODUCTION Ischemia and reperfusion injury (IRI)-elicited tissue injury contributes to morbidity and mortality in a wide range of pathologies, including myocardial infarction, ischemic stroke, acute kidney injury, trauma, circulatory arrest 1. Ischemia-reperfusion injury is also a major challenge during organ transplantation and cardiothoracic, vascular and general surgery 1. IRI, one of the biggest challenges for organ transplantation, continues to be a vital source of morbidity among recipients, especially in liver transplantation 2. With the enlarging shortage of available donor livers, the increased use of extended criteria donor grafts further increases IRI, adversely affecting both short-term and long-term outcomes of graft and patient survival 3. Numerous studies have investigated the benefits of pharmacological, heat shock, and ischemic preconditioning interventions aimed at decreasing liver IRI 4. However, the benefit was limited. Our center has been making great effort in conquering IRI and have developed a novel surgical technique called ischemia-free liver transplantation 5. It is an ultimate method to overcome IRI in liver transplantation, but there is still a long way to popularize it. As a result, it is still of great significance to study IRI and identify the core genes in the process and the underlying mechanism. Comprehensive bioinformatics analysis has been increasingly important as a method to study various pathological and physiological condition 6. By enrolling multiple omics or combining different types of omics, comprehensive bioinformatics analysis was able to recognize key factors that could have potentially pathogenic impact such as gene expression, protein function, and downstream pathways. With the rapid development of high-throughput sequencing technologies, several transcriptomic datasets on IRI of liver transplantation have become available in the Gene Expression Omnibus (GEO) database. Herein, we recruited 3 GEO datasets to conduct comprehensive analysis with the GEO dataset from our center. Moreover, we performed the first proteome of liver tissues to study liver IRI. Then the transcriptome and proteome were used for combined analysis to reveal key factors in liver IRI.
Project description:The clear benefits of ischemic preconditioning (IPC) in reducing ischemia reperfusion injury (IRI) remain indistinct in human liver transplantation. To further understand the mechanistic aspects of IPC in human deceased donor liver transplantation (DDLT), we performed microarray analyses to determine global gene expression profiles associated with IPC administration. Donor and recipient characteristics in both groups were comparable. Clinical data from our study subset and larger trial were similar. IPC increased expression of 10 transcripts at either time point with roles in: antioxidant defenses, immunological response, lipid biosynthesis, and xenobiotic metabolism. IPC decreased the expression of 1 cell development related transcript. Conclusions: 1) IPC in DDLT increased the expression of antioxidant transcripts similar to studies in animal IPC, anesthetic, and remote IPC. 2) IPC increased expression of lipogenic transcripts, which may be relevant to the clinically observed increased IRI in our IPC group. 3) Our microarray findings support our clinical observations and are compatible with the varied outcomes of hepatic IPC studies in human liver transplantation.
Project description:The initiation of donor derived dendritic cell (DC) adhesion and migration are one of the key events mediated by ischemia reperfusion injury (IRI) following solid organ transplantation. Recently we have been able to demonstrate that a single donor treatment with the synthetic metalloporphyrin cobalt protoporphyrin (CoPPIX) for heme oxygenase 1 (HO-1) induction results in the reduction of donor-derived DCs following IRI thus leading to the preservation of graft long-term function. Gene expression analysis in murine liver revealed the up-regulation of the signal transducer and activator of transcription 3 (STAT3) after CoPPIX treatment. Since it has been shown that CoPPIX is able to inhibit DC maturation, we could demonstrate that DC (-LPS) induced maturation guided by the secretion of pro-inflammatory cytokines and alloreactive T cell proliferation is dependent of STAT3 phosphorylation and independent of HO-1 activity. These observations highlight the immunomodulatory capacity of STAT3 which might be of further interest for the inhibition of immune response. Keywords: dendritic cells, heme oxygenase-1 (HO-1), STAT3, cobalt protoporphyrin For the analysis of gene expression profiles in vivo C57BL/6 mice were treated either with 5 mg/kg CoPPIX, i.p., 50 mg/kg MC, p.o. and 500 ppm CO for 6 or 24 hrs (3 animals in each group). Untreated C57BL/6 mice were used as controls (n=9). After 6 or 24 hrs of treatment animals were sacrificed and whole livers were harvested for analysis.
Project description:In this study, we shought to identify the cytokines produced by skin-resident T cells in normal skin, localize the receptors for these cytokines, and examine how these cytokines alter gene expression profiles of the cells bearing cognate receptors. Keywords: repeated measures experiment
Project description:In this study, we shought to identify the cytokines produced by skin-resident T cells in normal skin, localize the receptors for these cytokines, and examine how these cytokines alter gene expression profiles of the cells bearing cognate receptors. Experiment Overall Design: In this study, primary keratinocytes were treated with either IL-17, IL-22 or IFNg for 24 hours then harvested for RNA extraction and subsequent gene array analysis