scholarly journals Integrated Analysis of Prognostic Genes Associated With Ischemia–Reperfusion Injury in Renal Transplantation

2021 ◽  
Vol 12 ◽  
Author(s):  
Di Zhang ◽  
Yicun Wang ◽  
Song Zeng ◽  
Min Zhang ◽  
Xin Zhang ◽  
...  

BackgroundIschemia–reperfusion injury (IRI) remains an inevitable and major challenge in renal transplantation. The current study aims to obtain deep insights into underlying mechanisms and seek prognostic genes as potential therapeutic targets for renal IRI (RIRI).MethodsAfter systematically screening the Gene Expression Omnibus (GEO) database, we collected gene expression profiles of over 1,000 specimens from 11 independent cohorts. Differentially expressed genes (DEGs) were identified by comparing allograft kidney biopsies taken before and after reperfusion in the discovery cohort and further validated in another two independent transplant cohorts. Then, graft survival analysis and immune cell analysis of DEGs were performed in another independent renal transplant cohort with long-term follow-ups to further screen out prognostic genes. Cell type and time course analyses were performed for investigating the expression pattern of prognostic genes in more dimensions utilizing a mouse RIRI model. Finally, two novel genes firstly identified in RIRI were verified in the mouse model and comprehensively analyzed to investigate potential mechanisms.ResultsTwenty DEGs upregulated in the process of RIRI throughout different donor types (living donors, cardiac and brain death donors) were successfully identified and validated. Among them, upregulation of 10 genes was associated with poor long-term allograft outcomes and exhibited strong correlations with prognostic immune cells, like macrophages. Furthermore, certain genes were found to be only differentially expressed in specific cell types and remained with high expression levels even months after RIRI in the mouse model, which processed the potential to serve as therapeutic targets. Importantly, two newly identified genes in RIRI, Btg2 and Rhob, were successfully confirmed in the mouse model and found to have strong connections with NF-κB signaling.ConclusionsWe successfully identified and validated 10 IRI-associated prognostic genes in renal transplantation across different donor types, and two novel genes with crucial roles in RIRI were recognized for the first time. Our findings offered promising potential therapeutic targets for RIRI in renal transplantation.

2020 ◽  
Vol 31 (4) ◽  
pp. 716-730 ◽  
Author(s):  
Marc Johnsen ◽  
Torsten Kubacki ◽  
Assa Yeroslaviz ◽  
Martin Richard Späth ◽  
Jannis Mörsdorf ◽  
...  

BackgroundAlthough AKI lacks effective therapeutic approaches, preventive strategies using preconditioning protocols, including caloric restriction and hypoxic preconditioning, have been shown to prevent injury in animal models. A better understanding of the molecular mechanisms that underlie the enhanced resistance to AKI conferred by such approaches is needed to facilitate clinical use. We hypothesized that these preconditioning strategies use similar pathways to augment cellular stress resistance.MethodsTo identify genes and pathways shared by caloric restriction and hypoxic preconditioning, we used RNA-sequencing transcriptome profiling to compare the transcriptional response with both modes of preconditioning in mice before and after renal ischemia-reperfusion injury.ResultsThe gene expression signatures induced by both preconditioning strategies involve distinct common genes and pathways that overlap significantly with the transcriptional changes observed after ischemia-reperfusion injury. These changes primarily affect oxidation-reduction processes and have a major effect on mitochondrial processes. We found that 16 of the genes differentially regulated by both modes of preconditioning were strongly correlated with clinical outcome; most of these genes had not previously been directly linked to AKI.ConclusionsThis comparative analysis of the gene expression signatures in preconditioning strategies shows overlapping patterns in caloric restriction and hypoxic preconditioning, pointing toward common molecular mechanisms. Our analysis identified a limited set of target genes not previously known to be associated with AKI; further study of their potential to provide the basis for novel preventive strategies is warranted. To allow for optimal interactive usability of the data by the kidney research community, we provide an online interface for user-defined interrogation of the gene expression datasets (http://shiny.cecad.uni-koeln.de:3838/IRaP/).


2018 ◽  
Vol 315 (1) ◽  
pp. H150-H158 ◽  
Author(s):  
Marie Hauerslev ◽  
Sivagowry Rasalingam Mørk ◽  
Kasper Pryds ◽  
Hussain Contractor ◽  
Jan Hansen ◽  
...  

Remote ischemic conditioning (RIC) protects against sustained myocardial ischemia. Because of overlapping mechanisms, this protection may be altered by glyceryl trinitrate (GTN), which is commonly used in the treatment of patients with chronic ischemic heart disease. We investigated whether long-term GTN treatment modifies the protection by RIC in the rat myocardium and human endothelium. We studied infarct size (IS) in rat hearts subjected to global ischemia-reperfusion (I/R) in vitro and endothelial function in healthy volunteers subjected to I/R of the upper arm. In addition to allocated treatment, rats were coadministered with reactive oxygen species (ROS) or nitric oxide (NO) scavengers. Rats and humans were randomized to 1) control, 2) RIC, 3) GTN, and 4) GTN + RIC. In protocols 3 and 4, rats and humans underwent long-term GTN treatment for 7 consecutive days, applied subcutaneously or 2 h daily transdermally. In rats, RIC and long-term GTN treatment reduced mean IS (18 ± 12%, P = 0.007 and 15 ± 5%, P = 0.002) compared with control (35 ± 13%). RIC and long-term GTN treatment in combination did not reduce IS (29 ± 12%, P = 0.55 vs. control). ROS and NO scavengers both attenuated IS reduction by RIC and long-term GTN treatment. In humans, I/R reduced endothelial function ( P = 0.01 vs. baseline). Separately, RIC and long-term GTN prevented the reduction in endothelial function caused by I/R; given in combination, prevention was lost. RIC and long-term GTN treatment both protect against rat myocardial and human endothelial I/R injury through ROS and NO-dependent mechanisms. However, when given in combination, RIC and long-term GTN treatment fail to confer protection. NEW & NOTEWORTHY Remote ischemic conditioning (RIC) and long-term glyceryl trinitrate (GTN) treatment protect against ischemia-reperfusion injury in both human endothelium and rat myocardium. However, combined application of RIC and long-term GTN treatment abolishes the individual protective effects of RIC and GTN treatment on ischemia-reperfusion injury, suggesting an interaction of clinical importance.


2009 ◽  
Vol 35 (2) ◽  
pp. 304-312 ◽  
Author(s):  
Niels P. van der Kaaij ◽  
Jolanda Kluin ◽  
Jack J. Haitsma ◽  
Michael A. den Bakker ◽  
Bart N. Lambrecht ◽  
...  

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