Expression data from donor lungs of cardiac death and brain death donors (re-analysis)
Ontology highlight
ABSTRACT: Ischemia reperfusion induced injury contributes to poor lung transplant outcomes.Microarrays were used to study the biological response of human lungs to the ischemia reperfusion process. Samples were collected from lung transplant cases at Toronto General Hospital. Lungs were donation after brain death (DBD)
Project description:Ischemia reperfusion induced injury contributes to poor lung transplant outcomes. We used microarrays to study the biological response of human lungs to the ischemia reperfusion process. Samples were collected from lung transplant cases at Toronto General Hospital. Lungs were donation after brain death (DBD)
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: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:Ex vivo lung perfusion restores normothermia, ventilation and circulation to donor lungs, typically after a period of cold ischemia. This allows donor lungs to be evaluated prior to transplantation. We used microarrays to study the biological response of human lungs to Ex Vivo Lung Perfusion. Samples were collected from donor lungs at Toronto General Hospital. Lungs were donation after brain death (DBD)
Project description:Deceased kidney donation after brain death (DBD) is the main source of transplants, yet these grafts yield inferior transplant outcomes when compared to living donation. In brain death, cerebral injury contributes to systemic biological dysregulation, causing significant cellular stress in donor kidneys that adversely impacts the quality of grafts. Here, we hypothesized that proteolytic processes in DBD kidneys might lead to podocyte damage with subsequent development of post-transplant dysfunction. Using protein topography and migration analysis platform (PROTOMAP), we mapped degradation profiles of cytoskeletal proteins in DBD kidneys. Cytoskeletal proteolytic degradation was further studied by Immunoblotting on a separate cohort of deceased and living donor kidney biopsies. To investigate potential mechanism of kidney cytoskeletal protein degradation, in-vitro human podocytes and ex-vivo precision-cut human kidney slices were employed. We found novel proteolytic profiles of key podocyte cytoskeletal proteins in donor kidneys associated with suboptimal posttransplant function. These were unique to brain-death and were not observed in circulatory-death or living-donor kidneys. Talin-specific protein degradation in DBD kidneys indicated Calpain-1 activation may have a key role in proteolytic processes observed in the dysfunctional kidneys. Investigation of the underlying mechanism suggests that Transforming-Growth Factor-β (TGFβ) induces Calpain-1 activation, leading to brain-death specific podocyte degradation patterns and dysregulation of actin cytoskeleton; events that were prevented, in-vitro, by Calpain inhibition. Conclusion Our data demonstrate that podocyte protein degradation impacts the quality of DBD kidneys, propose a role of TGFβ mediated Calpain-1 proteolytic processing of cytoskeletal Talin-1, suggesting therapeutic opportunities to prevent kidney dysfunction.
Project description:Cold ischemia-reperfusion induced injury contributes to poor lung transplant outcomes. We used transcriptome sequencing to study the biological response of mouse lungs to the cold ischemia-reperfusion process. Mouse orthotopic left LTx was performed with standard cuff techniques. Briefly, the donor lungs were recovered after being flushed with 10ml low potassium dextran (LPD) solution and inflated with 50% oxygen. Cold ischemia was induced by storing donor lungs in 20ml LPD at 4°C for 24 hours. Then, the left donor lung was cuffed and implanted into recipients within 45 minutes. After the 4-hour reperfusion, the recipient mice were sacrificed and the transplanted lungs were collected.
Project description:BACKGROUND: Hypovolemia is common in lung donors before or after brain death. However, its impact on primary graft function (PGD) remains obscure. METHODS: A clinically relevant two-hit model of PGD was established by integrating hypovolemic shock (HS) and cold ischemia-reperfusion in a mouse model of orthotopic lung transplantation (LTx) from C57BL/6 to Balb/c. At -48 hours, HS was induced to donor by withdrawal of blood from femoral artery and keeping the mean arterial pressure at 15±5 mmHg for 4 h. At -24 hours, donor lungs were retrieved from mice with or without HS and stored at 0ºC until transplantation. CD11b-DTR mice were used as donor and treated with Diphtheria Toxin (DT) to deplete graft-infiltrating macrophages. RESULTS: HS mainly caused macrophage-predominant infiltration around pulmonary artery injury systemic inflammatory response, but little impairment of lung function even if in combination with cold ischemia-reperfusion. Transcriptional profiling showed HS pretreatment increased pulmonary damage and alveolar remodeling but ameliorated inflammatory infiltration when compared to one-hit model of 12 hours cold ischemia-reperfusion injury. The allografts with donor DT-treatment one day ahead of HS showed injury and dysfunction at donation and worsened further at 24 hours reperfusion, whereas the allografts with recipient DT-treatment immediately after transplantation showed similar function and histology to the control treated with saline. CONCLUSION: Donor hypovolemia causes pulmonary artery injury and infiltration but has little impact on allograft function, even in combination with 24 h cold ischemia. Graft-infiltrating macrophages are critical in protecting graft from HS-induced injury and cold ischemia-reperfusion injury.
Project description:Ischemia reperfusion (IR) is an unavoidable step of organ transplantation. IR-induced injury constrains the number of donor lungs used for transplant. Here we performed longitudinal single-cell RNA sequencing (scRNA-seq) from human lungs of six individuals who underwent lung transplantation. Lung biopsies were collected after cold preservation and 2-hour reperfusion for each individual resulting in the profiling of 108,613 cells in total.
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.
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