Ischemia and reperfusion injury in kidney transplantation : relevant mechanisms in injury and repair

Ischemia and reperfusion injury (IRI) is a complex pathophysiological phenomenon, inevitable in kidney transplantation and one of the most important mechanisms for non- or delayed function immediately after transplantation. Long term, it is associated with acute rejection and chronic graft dysfunction due to interstitial fibrosis and tubular atrophy. Recently, more insight has been gained in the underlying molecular pathways and signalling cascades involved, which opens the door to new therapeutic opportunities aiming to reduce IRI and improve graft survival. This review systemically discusses the specific molecular pathways involved in the pathophysiology of IRI and highlights new therapeutic strategies targeting these pathways

Molecular Aspects of Volatile Anesthetic-Induced Organ Protection and Its Potential in Kidney Transplantation

Ischemia reperfusion injury (IRI) is inevitable in kidney transplantation and negatively impacts graft and patient outcome. Reperfusion takes place in the recipient and most of the injury following ischemia and reperfusion occurs during this reperfusion phase; therefore, the intra-operative period seems an attractive window of opportunity to modulate IRI and improve short- and potentially long-term graft outcome. Commonly used volatile anesthetics such as sevoflurane and isoflurane have been shown to interfere with many of the pathophysiological processes involved in the injurious cascade of IRI. Therefore, volatile anesthetic (VA) agents might be the preferred anesthetics used during the transplantation procedure. This review highlights the molecular and cellular protective points of engagement of VA shown in in vitro studies and in vivo animal experiments, and the potential translation of these results to the clinical setting of kidney transplantation

Indigenous approaches to health assessment: a scoping review protocol.

BACKGROUND: Health assessment tools developed using mainstream or Western concepts have been widely used in clinical practice worldwide. However, even culturally adapted or culturally based tools may not be relevant in other social contexts if they are grounded in Western beliefs and perspectives. The application of mainstream assessment tools, when used in Indigenous populations, can lead to the inappropriate application of normative data and inaccurate or biased diagnosis of conditions as Indigenous concepts of health differ from Western biomedical concepts of health. Thus, considering the need for culturally meaningful, sensitive, safe, and unbiased health assessment approaches and instruments over recent years, tools have been developed or adapted by and with Indigenous populations in Australia, Aotearoa/New Zealand, Canada, and the United States. However, there is no existing systematic or scoping review to identify the methods and approaches used in adapting or developing health assessment tools for use with the Indigenous population in Australia, Aotearoa/New Zealand, Canada, and the United States. METHODS: In response to these gaps, we are working with a First Nations Community Advisory Group in Northern Ontario, Canada, to undertake a scoping review following the 2020 JBI methodology for scoping reviews. A systematic search will be conducted in PubMed, APA PsychINFO, CINAHL, MEDLINE, Web of Science, Bibliography of Native North Americans, Australian Indigenous Health info data set, and Indigenous Health Portal. Two reviewers will independently screen all abstracts and full-text articles for inclusion using criteria co-developed with an advisory group. We will chart the extracted information and summarize and synthesize the data. The summarized findings will be presented to a Community Advisory Group, including First Nations community partners, an Elder, and community members, and their feedback will be incorporated into the discussion section of the scoping review. DISCUSSION: This scoping review involves iterative consultation with the Indigenous and non-Indigenous scholars, First Nations Community Advisory Group, and community partners throughout the research process. This review aims to summarize the evidence on standard ethical approaches and practices used in Indigenous research while adapting or developing health assessment tools. It will inform the larger study focused on developing an Indigenous Functional Assessment tool. Further, it will seek whether the Indigenous ways of knowing and equitable participation of Indigenous people and communities are incorporated in the Indigenous research process. SYSTEMATIC REVIEW REGISTRATION: Open Science Framework https://osf.io/yznwk

Renoprotective capacities of non-erythropoietic EPO derivative, ARA290, following renal ischemia/reperfusion injury

BACKGROUND: ARA290 is a non-erythropoietic EPO derivative which only binds to the cytoprotective receptor complex (EPOR(2)-βcR(2)) consisting of two EPO-receptors (EPOR) and two β common receptors (βcR). ARA290 is renoprotective in renal ischemia/reperfusion (I/R). In a renal I/R model we focussed on timing of post-reperfusional administration of ARA290. Furthermore, we investigated the anti-inflammatory properties of ARA290. METHODS: Twenty-six male Lewis/HanHsd rats were exposed to unilateral ischemia for 30 minutes, with subsequent removal of the contralateral kidney. Post-reperfusion, ARA290 was administered early (one hour), late (four hours) or repetitive (one and four hours). Saline was used as vehicle treatment. Rats were sacrificed after three days. RESULTS: Early ARA290 treatment improved renal function. Late- or repetitive treatment tended to improve clinical markers. Furthermore, early ARA290 treatment reduced renal inflammation and acute kidney injury at three days post-reperfusion. Late- or repetitive treatment did not affect inflammation or acute kidney injury. CONCLUSIONS: ARA290 attenuated renal ischemia/reperfusion injury. This study showed the anti-inflammatory effect of ARA290 and suggests early administration in the post-reperfusional phase is most effective. ARA290 is a candidate drug for protection against ischemic injury following renal transplantation

ARA290, a non-erythropoietic EPO derivative, attenuates renal ischemia/reperfusion injury

BACKGROUND: In contrast with various pre-clinical studies, recent clinical trials suggest that high dose erythropoietin (EPO) treatment following kidney transplantation does not improve short-term outcome and that it even increases the risk of thrombotic events. ARA290 is a non-erythropoietic EPO derivative and does not increase the risk of cardiovascular events, but potentially has cytoprotective capacities in prevention of renal ischemia/reperfusion injury. METHODS: Eight female Dutch Landrace pigs were exposed to unilateral renal ischemia for 45 minutes with simultaneous cannulation of the ureter of the ischemic kidney. ARA290 or saline was administered by an intravenous injection at 0, 2, 4 and 6 hours post-reperfusion. The animals were sacrificed seven days post-reperfusion. RESULTS: ARA290 increased glomerular filtration rate during the observation period of seven days. Furthermore, ARA290 tended to reduce MCP-1 and IL-6 expression 15 minutes post-reperfusion. Seven days post-reperfusion ARA290 reduced interstitial fibrosis. CONCLUSIONS: The improvement in renal function following renal ischemia/reperfusion and reduced structural damage observed in this study by ARA290 warrants further investigation towards clinical application

Peri-Operative Kinetics of Plasma Mitochondrial DNA Levels during Living Donor Kidney Transplantation

During ischemia and reperfusion injury (IRI), mitochondria may release mitochondrial DNA (mtDNA). mtDNA can serve as a propagator of further injury but in specific settings has anti-inflammatory capacities as well. Therefore, the aim of this study was to study the perioperative dynamics of plasma mtDNA during living donor kidney transplantation (LDKT) and its potential as a marker of graft outcome. Fifty-six donor-recipient couples from the Volatile Anesthetic Protection of Renal Transplants-1 (VAPOR-1) trial were included. Systemic venous, systemic arterial, and renal venous samples were taken at multiple timepoints during and after LDKT. Levels of mtDNA genes changed over time and between vascular compartments. Several donor, recipient, and transplantation-related variables significantly explained the course of mtDNA genes over time. mtDNA genes predicted 1-month and 24-month estimated glomerular filtration rate (eGFR) and acute rejection episodes in the two-year follow-up period. To conclude, mtDNA is released in plasma during the process of LDKT, either from the kidney or from the whole body in response to transplantation. While circulating mtDNA levels positively and negatively predict post-transplantation outcomes, the exact mechanisms and difference between mtDNA genes are not yet understood and need further exploration.</p