Project description:Acute rejection remains an important risk factor affecting the survival of recipients following transplantation. Bone marrow mesenchymal stem cells (BMMSCs) are used in the treatment of organ transplantation due to their immunomodulatory ability. BMMSCs were isolated from rat bone marrow and modified with the adenovirus for heme oxygenase 1 (HO-1) gene. Saline solution, BMMSCs or HO-1/BMMSCs were perfused into the donor liver in vitro using a normothermic machine perfusion (NMP) system, followed by liver transplantation. The liver grafts were collected at 7 days post-transplantation. Gene chip technology was used to detect differential gene expression.
Project description:Because of inherent differences between deceased donor (DD) and living donor (LD) liver grafts, we hypothesize that the molecular signatures will be unique, correlating with specific biologic pathways and clinical patterns. Following reperfusion, 579 genes in DD grafts and 1324 genes in LDs were differentially expressed (p<0.005). Many up-regulated LD genes were related to regeneration, biosynthesis and cell cycle, and a large number of down-regulated genes were linked to hepatic metabolism and energy pathways correlating with post-transplant clinical laboratory findings. There was significant up-regulation of inflammatory/immune genes in both DD and LD, each with a distinct pattern. Gene expression patterns of select genes associated with inflammation and regeneration in LD and DD grafts correlated with protein expression. Unique patterns of early gene expression are seen in LD and DD liver grafts, correlating with protein expression and clinical results, demonstrating distinct inflammatory profiles and significant down-regulation of metabolic pathways in LD grafts. Keywords: liver transplantation, live donor transplantation, liver regeneration, microarrays, mRNA expression, reperfusion injury
Project description:Because of inherent differences between deceased donor (DD) and living donor (LD) liver grafts, we hypothesize that the molecular signatures will be unique, correlating with specific biologic pathways and clinical patterns. Following reperfusion, 579 genes in DD grafts and 1324 genes in LDs were differentially expressed (p<0.005). Many up-regulated LD genes were related to regeneration, biosynthesis and cell cycle, and a large number of down-regulated genes were linked to hepatic metabolism and energy pathways correlating with post-transplant clinical laboratory findings. There was significant up-regulation of inflammatory/immune genes in both DD and LD, each with a distinct pattern. Gene expression patterns of select genes associated with inflammation and regeneration in LD and DD grafts correlated with protein expression. Unique patterns of early gene expression are seen in LD and DD liver grafts, correlating with protein expression and clinical results, demonstrating distinct inflammatory profiles and significant down-regulation of metabolic pathways in LD grafts. Experiment Overall Design: Microarray profiles of 63 biopsies in 13 DD and 8 LD liver grafts done at serial time points (procurement - No Manipulation, backbench - Cold Preservation, and 1-hour post-reperfusion - Post reperfusion) were compared between groups using class comparisons, network and biological function analyses. Specific genes were validated by quantitative PCR and immunopathology. Clinical findings were also compared.
Project description:To find out acute rejection (AR) associated microRNAs, we have employed Agilent microRNA microarray as a discovery platform to identify microRNAs with the potential to distinguish AR from controls. We first established a rat Orthotopic liver transplantation (OLT) model with AR, using Brown Norway (BN) rats that received OLT with liver grafts from Lewis rats (Lewis to BN). OLT with BN rats as the donors and recipients were also performed (BN to BN), and these rats served as the control group (non-rejection group, NR group). Then, global microRNA expression profiles of the plasma and grafts were evaluated and validated with high throughout microarray and RT-qPCR.
Project description:we assessed characteristic molecular and proteomic signatures in rat liver treated with drugs (pyrazinamide, ranitidine, enalapril, carbamazepine, and chlorpromazine) that are known to cause DILI in humans.
Project description:Liver are frequently declined for transplantation due to the donor age. It is still unclear how donor age affects the graft quality. Normothermic machine perfusion (NMP) has been proposed as a useful assessment tool prior to transplantation. We aimed to compare the performance of young and elderly rat liver grafts in a small animal NMP model. Grafts from 24 rats were procured, either 3 or 12 months old and perfused for 6 hours at 37°C or stored on ice as a reference group (n=6/group). Livers in both NMP groups cleared lactate and produced bile, with similar pressure, bile production, and pH levels. However, older rat livers showed higher peak transaminase and urea levels. Proteomic analysis revealed differences in protein composition, particularly higher levels of proteins related to oxidoreductase and catalytic activity in older livers. Older age appeared to increase susceptibility to oxidative stress in the livers.
Project description:we assessed characteristic molecular and proteomic signatures in rat liver treated with drugs (pyrazinamide, ranitidine, enalapril, carbamazepine, and chlorpromazine) that are known to cause DILI in humans. In the present study, we assessed the characteristic gene expression signature for DILI in a rat model. Rats were administered representative drugs that are already known to induce DILI in humans and transcriptomic changes in rat liver were analyzed. The representative drugs, which induce three types (hepatocellular, mixed, and cholestatic) of DILI, that were used in this study were pyrazinamide (PZA, 150~1500 mg/kg), ranitidine (RAN, 209.5~2095 mg/kg), enalapril (ENA, 148.65~1486.5 mg/kg), carbamazepine (CBZ, 97.85~978.5 mg/kg), and chlorpromazine (CPZ, 7.1~71 mg/kg).