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.
Project description:In DCD organ donation one of the significant problems for the organ is the inflammatory response due to ischaemia 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 preserved using hypothermic machine perfusion with cold University of Wisconsin solution with/without the addition of heparinoids low molecular weight heparin and pentosan polysulfate (PPS) followed by warm oxygenated perfusion with modified Krebs-Henseleit buffer to simulate early ischaemia reperfusion injury (IRI). The donor rats consisted of a control group cold perfusion group compared to warm perfusion and groups treated with either low molecular weight heparin or PPS to assess their activity in ameliorating IRI. We used equimolar pooled RNA samples from each group to perform an exploratory microarray experiment
Project description:Background: Strategies to improve long term renal allograft survival have been directed to recipient dependent mechanisms of renal allograft injury. In contrast, no such efforts have been made to optimize organ quality in the donor. In order to get insight into the deleterious gene pathways expressed at different time points during deceased kidney transplantation, transcriptomics was performed on kidney biopsies from a large cohort of deceased kidney transplants. Methods: A total of 554 kidney biopsies were taken from living and deceased donor kidneys at donation, after cold ischemia and after reperfusion. Transcriptomics by means of whole genome micro-array analyses followed by functional pathway analyses was performed. Results: Oxidative stress and complement- and coagulation pathways were uncovered as potential pathways for intervention in deceased donors. No genes were found to be differentially expressed between donation and cold ischemia. After reperfusion, pathways related to oxidative stress, NOD-like signalling, MAPK, cytokine-cytokine receptor, complement- and-coagulation and chemokines were enriched in kidneys from deceased organ donors. Pathways related to prolonged and worsening deprivation of oxygen were associated with delayed graft function of DCD grafts. Conclusions: The present study reveals oxidative stress and enrichment of complement and coagulation pathways in deceased donor kidneys. Future intervention therapies to optimize donor organ quality and prolong allograft survival should target oxidative stress and innate immune activation in the donor.
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: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: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: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:In DCD organ donation one of the significant problems for the organ is the inflammatory response due to ischaemia 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 preserved using hypothermic machine perfusion with cold University of Wisconsin solution with/without the addition of heparinoids low molecular weight heparin and pentosan polysulfate (PPS) followed by warm oxygenated perfusion with modified Krebs-Henseleit buffer to simulate early ischaemia reperfusion injury (IRI). The donor rats consisted of a control group cold perfusion group compared to warm perfusion and groups treated with either low molecular weight heparin or PPS 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 preserved by hypothermic machine perfusion with University of Wisconsin (UW) Solution for 3 hours followed by warm oxygenated perfusion with modified Krebs-Henseleit buffer for 30 minutes 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 PPS when used as supplements into perfusate solutions. Half of the donor kidney was used to extract RNA 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: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).