Wide gene expression profiling of ischemia-reperfusion injury in human liver transplantation

Abstract

Ischemia-reperfusion injury (IRI) causes up to 10% of early liver failures in humans and can lead to a higher incidence of acute and chronic rejection. So far, very few studies have investigated wide gene expression profiles associated with the IRI process. The discovery of novel genes activated by IRI might lead to the identification of potential target genes for the prevention or treatment of the injury. In our study, we compared gene expression levels in reperfused livers (RL group) vs. the basal values before retrieval from the donor (basal liver [BL] group) using oligonucleotide array technology. We examined 10 biopsies from 5 livers, analyzing approximately 33,000 genes represented on the Affymetrix HG-U133APlus 2.0 oligonucleotide arrays (Affymetrix, Santa Clara, CA). About 13,000 individual genes were considered expressed in at least 1 condition. A total of 795 genes whose expression is significantly modified by ischemia-reperfusion in human liver transplantation were identified in this study. Some of them are likely to be completely activated by IRI, as they are not expressed in basal livers. The supervised gene expression analysis revealed that at least 12% of the genes involved in the apoptotic process, 12.5% of the genes involved in inflammatory processes, and 22.5% of the genes encoding for heat shock proteins are differentially expressed in RL samples vs. BL samples. Furthermore, IRI induces the upregulation of some genes' coding for adhesion molecules and integrins. In conclusion, we have identified a relevant amount of early genes regulated in the human liver after 7-9 hours of cold ischemia and 2 hours from reperfusion, many of them not having been described before in this process. Their analyses may help us to better understand the pathophysiology of IRI and to characterize potential target genes for the prevention or treatment of the liver injury in order to increase the number of patients that successfully undergo transplantation. Liver Transpl 13:99-113, 2007. © Orthotopic liver transplantation has become an effective therapeutic approach for end-stage liver diseases. Advances in surgical procedures and immunosuppression protocols have considerably improved patient survival after liver transplantation. However, ischemiareperfusion injury (IRI), an antigen-independent component of the insult to the liver, represents a major problem affecting the outcome of liver transplantation.IRI causes up to 10% of early liver failures and can lead to a higher incidence of acute and chronic rejection. Liver IRI is mediated by several processes that lead to hepatocellular damage, which is triggered when the Abbreviations: IRI, ischemia-reperfusion injury; HO-1, heme oxygenase-1; BL, basal liver; RL, reperfused liver; GO, Gene Ontology; PCR, polymerase chain reaction; IL, interleukin; CCL, cystein cistein ligand; HSP, heat shock protein.

Pathogenesis of Hepatitis E Virus and Hepatitis C Virus in Chimpanzees: Similarities and Differences

“…The coefficient of determination (R 2 ) was higher for genes with greater magnitude of differential expression (i.e., the IFI6, CXCL9, and ISG15 genes) than that for genes with low-level differential expression (i.e., the HLA-C, HLA-DPB1, and B2M genes). However, qRT-PCR validated the positive microarray results for all genes that were selected for analysis based on a fold change of 2, and the comparison of all nine genes resulted in an R 2 of 0.75, which is comparable with those of other studies that used the Affymetrix platform to analyze liver tissues (11,29). For two HCV-infected chimpanzees (1628 and 1422) and two HEV-infected chimpanzees (1616 and 1374) the relative expression of IFN-␥ was measured by qRT-PCR as an indicator of the adaptive immune response (Fig.…”

The MAP Kinase Phosphatase-1 MKP-1/DUSP1 Is a Regulator of Human Liver Response to Transplantation

“…Although reports have already described mRNA expression profiles in human liver transplantation (6,7) Conti et al (6) or that of Defamie et al (7) (iii) a difference in the time point of samples analyzed (long [2-3 h] (27). …”

Gene Expression Profile in Liver Transplantation and the Influence of Gene Dysregulation Occurring in Deceased Donor Grafts

“…Hybridization data were normalized and quantified using Robust Multiarray Analysis (RMA) software [11]. DL and TL samples were collected as previously described [3]. Briefly, 10 liver biopsies were analyzed: 5 biopsies, from the donors, collected before explantation (DL group); 5 biopsies from the transplant recipients (TL group), collected 2-3 hours after liver reperfusion.…”

“…In a previous study [3] we have compared gene expression levels in transplanted livers, soon after reperfusion, versus basal gene expression levels, before liver retrieval from the donor. About 800 genes were found dysregulated after transplantation, but we have not analyzed the potential effects of brain death on the gene expression variations.…”

“…We have compared gene expression profile of both deceased donor livers (DL) and transplanted livers (TL) to gene expression data of liver tissue, retrieved from Array Express database, used as control (CL) [3,5]. This control was a set of livers from sudden death individuals without previous agonal state.…”