Project description:Ischemia-reperfusion (IR) injury, a ubiquitous consequence of liver transplantation, is a cause of early graft rejection and increased morbidity. At present, there are no effective strategies to reduce hepatic IR injury. Molecular mechanisms that promote cell survival under these circumstances are largely undefined. We examined changes in global gene expression at early reperfusion times to identify potential IR-mediated protective responses. Using a rat model of 30 minutes of 70% warm ischemia followed by reperfusion, RNA for microarray analysis was extracted from the non-ischemic and the ischemic-reperfused lobes at four reperfusion times: 0 (no reperfusion), 0.5, 2, and 6 hours. Differentially expressed genes and pathway analyses were used to identify IR-induced events. The transcriptome of the reperfused lobes was unique and discrete at each reperfusion time, showing no evidence of sustained changes of the gene expression alterations seen at 30 minutes of reperfusion. At all reperfusion times, a significant portion of gene expression changes in the reperfused lobes were present in the non-ischemic lobes. However, the earliest reperfusion time, 30 minutes, showed a marked increase in the expression of a set of immediate-early genes (c-Fos, c-Jun, Atf3, Egr1) that was exclusive to the reperfused lobe. Similarities of gene expression changes in the reperfused and the non-ischemic lobes at each time suggest that hemodynamics and/or circulating factors are potent stimuli in an IR model. However, early reperfusion events appear to reflect a cell-autonomous response that may be protective, thereby representing potential targets to ameliorate IR injury.
Project description:Ischemia-reperfusion injury (IRI) is a major cause of morbidity and mortality following conventional lung transplantation and warm ischemia may limit success of transplanting lungs from non-heart-beating donors. We sought to determine alterations in gene expression in rat lung tissue subjected to warm ischemia in vivo followed by reperfusion. Keywords: time course
Project description:6-plex TMT-based quantitative proteomics was used to analysis the proteomic profile in different stages of mouse hepatic ischemia-reperfusion injury.
Project description:This SuperSeries is composed of the following subset Series: GSE10652: Divergent genome expression profiles during hepatic ischemia in young and adult mice GSE10654: Age-dependent gene expression profiles after hepatic ischemia/reperfusion in mice Keywords: SuperSeries Refer to individual Series
Project description:NRVMs were subjected to varying durations of ischemia or ischemia+reperfusion using coverslip hypoxia. Expression profiling was used to identify genes that are differentially regulated in either event. We used microarrays to detail the global program of gene expression underlying ischemia and reperfusion using Coverslip Hypoxia and identified distinct classes of genes regulated during these processes. Experiment Overall Design: RNA was extracted from NRVMs subjected to varying durations of ischemia or ischemia+reperfusion and hybridized to rat genome Affymetrix arrays.
Project description:Ischemia/reperfusion injuries is a known complication to hepatic surgery. Ischemic pre- (IPC) and postconditioning (IPO) protects the liver against ischemia/reperfusion-injuries. Expression profiling were performed on liver biopsies seeking to identify molecular mediators of the protective properties. 48 rats were divided into 5 groups; sham (n=8), IRI (n=10), IPC (n=10), IPO (n=10) and IPC+IPO (n=10). All rats except sham rats were subjected to 30 min of total liver ischemia and 30 min of reperfusion before liver biopsies were sampled. In the IPC group, liver ischemia was preceded by 10 min of hepatic ischemia, followed by 10 min of reperfusion. IPO were performed by three cycles of 30 sec of reperfusion and 30 sec of ischemia, applied immediately after the 30 min of total liver ischemia. In the IPC+IPO group the two interventions were combined.
Project description:To reveal the alterations of mRNA profile in cerebral ischemia-reperfusion injury in rat. The SD rats were used to established the middle cerebral artery occlusion and reperfusion (MCAO/R) model. RNA-seq were performed to identify differences in gene expression.
Project description:Ischemic preconditioning is effective in limiting subsequent ischemic acute kidney injury in experimental models. microRNAs are an important class of post-transcriptional regulator and show promise as biomarkers of kidney injury. An evaluation was performed of the time- and dose-dependent effects of ischemic preconditioning in a rat model of functional (bilateral) ischemia-reperfusion injury. A short, repetitive sequence of ischemic preconditioning resulted in optimal protection from subsequent ischemia-reperfusion injury. A detailed characterization of microRNA expression in ischemic preconditioning/ischemia-reperfusion injury was performed by small RNA-Seq.
Project description:Ischemic preconditioning is effective in limiting subsequent ischemic acute kidney injury in experimental models. microRNAs are an important class of post-transcriptional regulator and show promise as biomarkers of kidney injury. An evaluation was performed of the time- and dose-dependent effects of ischemic preconditioning in a rat model of functional (bilateral) ischemia-reperfusion injury. A short, repetitive sequence of ischemic preconditioning resulted in optimal protection from subsequent ischemia-reperfusion injury. A detailed characterization of microRNA expression in ischemic preconditioning/ischemia-reperfusion injury was performed by Exiqon miRCURY microRNA array.
Project description:Experimental Design: 1. The goal of the experiment: Age-Dependent Gene Expression Profiles After Hepatic Ischemia/Reperfusion: Implications for the AP-1 and Ubiquitin-Proteosome Pathways 2. Brief description of the experiment: Hepatic ischemia/reperfusion (I/R) injury is a complication of liver surgery, transplantation and shock. Our previous studies have suggested there is an age-dependent response to I/R. In the present study, we examined global gene expression after liver I/R in young (4-5 weeks) and adult (12-14 months) mice using Affymetrix microarray. Gene expression was filtered based on a change in expression of 1.5-fold relative to respective controls and then analyzed by ANOVA. Seventy-two genes in young mice and 56 genes in adult mice had significantly increased expression. Of these, only 18 were up-regulated in both age groups. In young mice, 289 genes were down-regulated whereas in adult mice, 874 genes were decreased. Of these genes, 175 genes were decreased in both groups. Pathway and network analyses of up- and down-regulated gene lists revealed a number of notable differences between young and adult mice. Of these, we found that genes related to the activating protein-1 (AP-1) pathway were upregulated preferentially in young mice. This corresponded with an increase in AP-1 activation in young versus adult mice. Finally, we found that genes related to the ubiquitin-proteasome pathway were selectively down-regulated in adult mice. This was accompanied by reduced degradation of the inhibitory protein, I?B?, in adult mice. The data demonstrate specific, pathway- and network-related differences in gene expression profiles between young and adult mice in the response to I/R. More specifically, we have identified two pathways that may contribute to the superior response to I/R in young mice which represent potential therapeutic targets. Keywords: treated vs non treated 2 age groups of 6 young and 6 adult mice that underwent either 90 minutes of partial ischemia followed by 1 hour of reperfusion (n=3) or sham operation (n=3) We used microarray to uncover the genomic response after ischemia reperfusion in 2 different age groups