Project description:The microRNA expression profile in donation after cardiac death (DCD) livers its ability to identify primary non function DCD livers are a marginal organ and their usein transplantation is associated with a higher risk of primary non function (PNF), or early graft dysfunction (EGD).
Project description:The microRNA expression profile in donation after cardiac death (DCD) livers its ability to identify primary non function DCD livers are a marginal organ and their usein transplantation is associated with a higher risk of primary non function (PNF), or early graft dysfunction (EGD). We compared a three groups of DCD livers defined as PNF (n=7) retransplanted within a week, good functional outcome (n=7) AST < 1000IU/L and EGD (n=9) AST>2500IU/L . RNA was extracted from archived histology samples and miRNA expression was analysed using the affymetrix Genechip miRNA 2.0 assays.
Project description:Lung donation after cardiac death (DCD), in contrast to donation after brain death (DBD), is a promising and increasingly common method to help relieve the shortage of donor organs. However, the pathogenetic consequences of retrieved lungs after DCD vs. DBD have not been clarified. We aimed to study the differential gene expression profiles in lungs of DCD and DBD patients.
Project description:Lung donation after cardiac death (DCD), in contrast to donation after brain death (DBD), is a promising and increasingly common method to help relieve the shortage of donor organs. However, the pathogenetic consequences of retrieved lungs after DCD vs. DBD have not been clarified. We aimed to study the differential gene expression profiles in lungs of DCD and DBD patients. DCD patients were matched with DBD lung transplant cases from a prospectively maintained database. The number of tissue samples included in this study was 6 pre- and 5 post-transplant in DCD and 12 pre- and 12 post-transplant in DBD for a total number of 35 lung tissue samples.
Project description:The goals of this study are to investigate whether the defects of energy metabolism and/or mitochondria occurs in Nonalcoholic fatty liver disease (NAFLD), we performed liver transcriptome analysis from livers of donors who underwent organ donation after cardiac death (DCD; 6 non-NAFLD donors, 5 NAFLD donors). In this screen, a cluster of 462 transcripts were up-regulated and 447 transcripts were down-regulated in response to NAFLD. Among these differentially expressed genes , gene sets that contribute to endoplasmic reticulum stress, intrinsic apoptosis and cytokine production were enriched in NAFLD livers, whereas lipid metabolic process were suppressed in NAFLD livers, accompanied with deficient expression of the mitochondrial matrix enzyme.
Project description:The decreasing numbers of Donation after Brain Death (DBD) donors necessitates the comprehensive evaluation of Donation after Cardiac Death Donors (DCD) as a source of pancreata. The aim of this study was to characterize pancreata and islets from DCD and DBD donors with respect to markers of cellular stress that may indicate compromised islet quality. Immunohistochemical staining of pre-isolation pancreas biopsies found increased numbers of caspase 3 positive islets in DBD, while markers of oxidative stress (nitrotyrosine, CML, and HNE) were elevated in DCD. Assessment of islet quality by standard (yield, morphology, fluorescence microscopy, and glucose stimulated insulin secretion) and novel methods (flow cytometry, HPLC quantification of ATP) did not reveal significant differences. However, the post culture loss of DCD islets was increased compared to DBD, and DCD islets showed delayed functional potency when transplanted into diabetic NOD.scid mice. Microarray analysis of cultured islets showed increased expression of multiple stress pathway related genes in DCD compared to DBD. Together these data indicate that the current standard donor management, pancreas recovery and preservation practices are insufficient to quench the oxidative stress injury suffered by DCD islets which leads to loss in culture and may complicate their use in clinical transplant. Keywords: cell type comparison
Project description:Due to organ shortage, the transplantation community are increasingly using kidney from deceased donors such as donation after circulatory death (DCD) and donation after brain death (DBD). However, DCD donation have increased delayed graft function compared to DBD, an underline mechanism is still not well defied at the molecular level. In this study, we employed a rat model to mimic warm ischemia (45 mins) and reperfusion injury (IRI) for 4h and 24h. Apoptotic and tissue histological staining confirmed apoptosis and necrosis occurred at 4h and 24h post IRI respectively. Tissue proteome study revealed acute phase response, coagulation and complement activation and lipid X receptor activation as major pathway altered in intervention kidneys. Metabolomics follow up disclosed an increased level of lipids and fatty acids (FA). Mitochondrial function analysed by mitochondrial complex I activity and oxygen consumption and ATP levels in intervention kidney tissues were maintained 4h post IRI, but was significantly reduced 24h post IRI. Integrated proteo-metabolome analysis discovered an increased FA beta-oxidation 4h post IRI to sustain energy production. Kidney function were declined 24h post IRI indicated by increased blood creatinine and lactate levels. This study provides the frame work for the design of future metabolic intervention strategies to minimize kidney injury.
Project description:Background and Aims: Liver transplantation provides an effective cure for end-stage liver disease but is hampered by a severe organ shortage. Normothermic machine perfusion (NMP) of donor livers allows dynamic preservation in addition to viability assessment prior to transplantation. Little is known about the injury and repair mechanisms induced during NMP. Therefore, we examined gene and protein expression changes in a cohort of discarded human livers during NMP, stratified by liver viability. Approach and Results: 6 human livers from donation after circulatory death (DCD) underwent 12 hours of NMP, of which 3 met viability criteria. We applied bulk transcriptomics to evaluate differences in gene expression relating to injury, repair, and regenerative responses among livers based on viability. Viable livers demonstrated robust activation of innate immunity after 3 hours of NMP followed by enrichment of pro-repair and pro-survival mechanisms. Nonviable livers demonstrated delayed and persistent enrichment of innate immune responses. Viable livers demonstrated effective induction of autophagy, the cellular repair and homeostasis pathway, compared to nonviable livers. Enrichment of pro-survival signaling was also broader in these livers. Conclusions: NMP of discarded DCD human livers results in ischemia-reperfusion injury, but importantly activates autophagy as a means of cellular repair. More pronounced activation of autophagy was seen in livers that met viability criteria for transplantation. Therapeutic targeting of the autophagy mechanism may allow rehabilitation of nonviable livers for transplantation.
Project description:Ischemia-reperfusion injury during liver transplantation is responsible for early allograft dysfunction (EAD) and failure, both of which are associated with a high risk of morbidity and mortality in the recipient. The purpose of this study was to study major transcriptional alterations in livers procured from different types of human liver donors in order to identify genetic profiles predictive of post-implantation function. We have analyzed samples form living donors (LD), donors after cardiac death (DCD), donors after brain death, with subsequent post-implantation EAD in the recipient (DBD-EAD); and donors after brain death without EAD (DBD). Two samples were obtained from each donor: sample A was taken immediately before cold perfusion (baseline) and sample B 2h after portal reperfusion. We identified clear differences in gene expression patterns according to donor source. Both samples A and B from DBD-EAD and DCD demonstrated over-expression of pro-apoptotic and inflammatory transcripts. However, in DBD and LD, expression of these genes was low at baseline and rose only after reperfusion. DBD and LD demonstrated the greatest increase in overall genetic expression after reperfusion when sample B was contrasted with A, indicating less baseline graft injury in these two groups. Grafts from LD were characterized by activation of transcripts related to anti-ischemic and regenerative processes and fewer pro-inflammatory gene transcripts. This transcriptional events occurring in liver allografts could allow for the prediction of post-transplant function. Pro-inflammatory and ischemic transcriptional changes in the grafts are directly related to donor type and may be useful targets for the development of future therapeutic strategies. The complete database comprised the expression for samples taken from 33 liver grafts. Sample A was taken immediately before cold perfusion (baseline) and sample B 2 h after portal reperfusion. Donors were from one of four groups: living (LD); after cardiac death (DCD); after brain death, with subsequent post-implantation EAD in the recipient (DBD-EAD); and after brain death without EAD (DBD). RNA was extracted from the 66 samples and analyzed using Illumina Beadarray technology. A group of 3 samples from healthy volunteers and 3 samples form LD taken at the start of surgery are included as controls or reference samples. This dataset is part of the TransQST collection.