A mouse model of renal ischemia-reperfusion injury solely induced by cold ischemia

Neutrophil-Mediated Nanozyme Delivery System for Acute Kidney Injury Therapy

Reactive oxygen species (ROS) scavenging of nanozymes toward acute kidney injury (AKI) is a current promising strategy, however, the glomerular filtration barrier (GFB) limits their application for treating kidney related diseases. Here, a neutrophil-mediated delivery system able to hijack neutrophil to transport nanozyme-loaded cRGD-liposomes to inflamed kidney for AKI treatment by cRGD targeting integrin αvβ1 is reported. The neutrophil-mediated nanozyme delivery system demonstrated great antioxidant and anti-apoptosis ability in HK-2 and NRK-52E cell lines. Moreover, in ischemia-reperfusion (I/R) induced AKI mice, a single dose of LM@cRGD-LPs 12 h post-ischemia significantly reduces renal function indicators, alleviates renal pathological changes, and inhibits apoptosis of renal tubular cells and the expression of renal tubular injured marker, thus remarkably reducing the damage of AKI. Mechanistically, the treatment of LM@cRGD-LPs markedly inhibits the process of Nrf2 to the nucleus and reduces the expression of the downstream HO-1, achieves a 99.51% increase in renal tissue Nrf2 levels, and an 86.31% decrease in HO-1 levels after LM@cRGD-LPs treatment. In short, the strategy of neutrophil-mediated nanozyme delivery system hold great promise as a potential therapy for AKI or other inflammatory diseases.

Determination of Maximum Tolerable Cold Ischemia Time in a Mouse Model of Cervical Heterotopic Uterus Transplantation

BACKGROUND

Uterus transplantation (UTx) is an emerging treatment for uterine factor infertility. Determining the maximum tolerable cold ischemia time is crucial for successful UTx. However, the limit for cold ischemia in the uterus is unclear. This study aimed to examine cold ischemia's effects on mouse uteri and identify the maximum cold ischemia duration that uteri can endure.

METHODS

We systematically assessed the tolerance of mouse uteri to extended cold ischemia, 24 h, 36 h, and 48 h, using the cervical heterotopic UTx model. Multiple indicators were used to evaluate ischemia-reperfusion injury, including reperfusion duration, macroscopic examination, oxidative stress, inflammation, and histopathology. The function of transplants was evaluated through estrous cycle monitoring and embryo transfer.

RESULTS

Mouse uteri subjected to 48 h of cold ischemia exhibited significant delays and insufficiencies in reperfusion, substantial tissue necrosis, and loss of the estrous cycle. Conversely, uteri that underwent cold ischemia within 36 h showed long survival, regular estrous cycles, and fertility.

CONCLUSIONS

Our study demonstrated that mouse uteri can endure at least 36 h of cold ischemia, extending the known limits for cold ischemia and providing a pivotal reference for research on the prevention and treatment of cold ischemic injury in UTx.

Interleukin-2/anti-interleukin-2 immune complex attenuates cold ischemia-reperfusion injury after kidney transplantation by increasing renal regulatory T cells

BACKGROUND

Cold ischemia-reperfusion injury (IRI) is an unavoidable complication of kidney transplantation. We investigated the role of regulatory T cells (Treg) in cold IRI and whether the interleukin (IL)-2/anti-IL-2 antibody complex (IL-2C) can ameliorate cold IRI.

METHODS

We developed a cold IRI mouse model using kidney transplantation and analyzed the IL-2C impact on cold IRI in acute, subacute and chronic phases.

RESULTS

Treg transfer attenuated cold IRI, while Treg depletion aggravated cold IRI. Next, IL-2C administration prior to IRI mitigated acute renal function decline, renal tissue damage and apoptosis and inhibited infiltration of effector cells into kidneys and pro-inflammatory cytokine expression on day 1 after IRI. On day 7 after IRI, IL-2C promoted renal regeneration and reduced subacute renal damage. Furthermore, on day 28 following IRI, IL-2C inhibited chronic fibrosis. IL-2C decreased reactive oxygen species-mediated injury and improved antioxidant function. When IL-2C was administered following IRI, it also increased renal regeneration with Treg infiltration and suppressed renal fibrosis. In contrast, Treg depletion in the presence of IL-2C eliminated the positive effects of IL-2C on IRI.

CONCLUSION

Tregs protect kidneys from cold IRI and IL-2C inhibited cold IRI by increasing the renal Tregs, suggesting a potential of IL-2C in treating cold IRI.

KEY POINTS

Interleukin (IL)-2/anti-IL-2 antibody complex attenuated acute renal injury, facilitated subacute renal regeneration and suppressed chronic renal fibrosis after cold ischemia-reperfusion injury (IRI) by increasing the renal Tregs. IL-2/anti-IL-2 antibody complex decreased reactive oxygen species-mediated injury and improved antioxidant function. This study suggests the therapeutic potential of the IL-2/anti-IL-2 antibody complex in kidney transplantation-associated cold IR.

Evaluation of renal cold ischemia-reperfusion injury with intravoxel incoherent motion diffusion-weighted imaging and blood oxygenation level-dependent MRI in a rat model

Purpose: Cold ischemia-reperfusion injury (CIRI) is one of the most serious complications following renal transplantation. The current study investigated the feasibility of Intravoxel Incoherent Motion (IVIM) imaging and blood oxygenation level-dependent (BOLD) in the evaluation of different degrees of renal cold ischemia-reperfusion injury in a rat model. Methods: Seventy five rats were randomly divided into three groups (N = 25 for each group): T0: sham-operated group, T2/T4: CIRI groups with different cold ischemia hours (2, 4 h, respectively). The rat model of CIRI group was established by left kidney cold ischemia with right nephrectomy. All the rats received a baseline MRI before the surgery. Five rats in each group were randomly selected to undergo an MRI examination at 1 h, day 1, day 2 and day 5 after CIRI. The IVIM and BOLD parameters were studied in the renal cortex (CO), the outer stripe of the outer medulla (OSOM), and the inner stripe of the outer medulla (ISOM) followed by histological analysis to examine Paller scores, peritubular capillary (PTC) density, apoptosis rate and biochemical indicators to obtain the contents of serum creatinine (Scr), blood urea nitrogen (BUN), superoxide dismutase (SOD) and malondialdehyde (MDA). Results: The D, D*, PF and T2* values in the CIRI groups were lower than those in the sham-operated group at all timepoints (all p < 0.05). The prolonged cold ischemia times resulted in gradually lower D, D*, PF and T2* values (all p < 0.05). The D and T2* values of cortex and OSOM in Group T0 and T2 returned to the baseline level (all p > 0.05) except Group T4. The D* and PF values of cortex, OSOM and ISOM in Group T2 and T4 still remained below the normal levels (all p < 0.05) except Group T0. D, D*, PF and T2* values were strongly correlated with histopathological (Paller scores, PTC density and apoptosis rate) and the biochemistry indicators (SOD and MDA) (|r|>0.6, p < 0.001). D*, PF and T2* values were moderately to poorly correlated with some biochemistry indicators (Scr and BUN) (|r|<0.5, p < 0.05). Conclusion: IVIM and BOLD can serve as noninvasive radiologic markers for monitoring different degrees of renal impairment and recovery after renal CIRI.

Enhancing the expression of a key mitochondrial enzyme at the inception of ischemia-reperfusion injury can boost recovery and halt the progression of acute kidney injury

Hydrodynamic fluid delivery has shown promise in influencing renal function in disease models. This technique provided pre-conditioned protection in acute injury models by upregulating the mitochondrial adaptation, while hydrodynamic injections of saline alone have improved microvascular perfusion. Accordingly, hydrodynamic mitochondrial gene delivery was applied to investigate the ability to halt progressive or persistent renal function impairment following episodes of ischemia-reperfusion injuries known to induce acute kidney injury (AKI). The rate of transgene expression was approximately 33% and 30% in rats with prerenal AKI that received treatments 1 (T_1hr) and 24 (T_24hr) hours after the injury was established, respectively. The resulting mitochondrial adaptation via exogenous IDH2 (isocitrate dehydrogenase 2 (NADP+) and mitochondrial) significantly blunted the effects of injury within 24 h of administration: decreased serum creatinine (≈60%, p < 0.05 at T_1hr; ≈50%, p < 0.05 at T_24hr) and blood urea nitrogen (≈50%, p < 0.05 at T_1hr; ≈35%, p < 0.05 at T_24hr) levels, and increased urine output (≈40%, p < 0.05 at T_1hr; ≈26%, p < 0.05 at T_24hr) and mitochondrial membrane potential, Δψ_m, (≈ by a factor of 13, p < 0.001 at T_1hr; ≈ by a factor of 11, p < 0.001 at T_24hr), despite elevated histology injury score (26%, p < 0.05 at T1_hr; 47%, p < 0.05 at T_24hr). Therefore, this study identifies an approach that can boost recovery and halt the progression of AKI at its inception.

No safe renal warm ischemia time-The molecular network characteristics and pathological features of mild to severe ischemia reperfusion kidney injury

Ischemic acute kidney injury (AKI) has always been a hot and difficult research topic in the field of renal diseases. This study aims to illustrate the safe warm ischemia time of kidney and the molecular network characteristics and pathological features of mild to severe ischemia reperfusion kidney injury. We established varying degrees of renal injury due to different ischemia time (0 min, 16 min, 18 min, 20 min, 22 min, 24 min, 26 min, 28 min, and 30 min) on unilateral (left kidney) ischemia-reperfusion injury and contralateral (right kidney) resection (uIRIx) mouse model. Mice were sacrificed 24 h after uIRIx, blood samples were harvested to detect serum creatinine (Scr), and kidney tissue samples were harvested to perform Periodic Acid-Schiff (PAS) staining and RNA-Seq. Differentially expressed genes (DEGs) were identificated, time-dependent gene expression patterns and functional enrichment analysis were further performed. Finally, qPCR was performed to validated RNA-Seq results. Our results indicated that there was no absolute safe renal warm ischemia time, and every minute of ischemia increases kidney damage. Warm ischemia 26min or above in mice makes severe kidney injury, renal pathology and SCr were both significantly changed. Warm ischemia between 18 and 26 min makes mild kidney injury, with changes in pathology and renal molecular expression, while SCr did not change. No obvious pathological changes but significant differences in molecular expression were found less than 16min warm ischemia. There are two key time intervals in the process of renal ischemia injury, 0 min-16 min (short-term) and 26 min-28 min (long-term). Gene expression of immune-related pathways were most significantly down-regulated in short-term ischemia, while metabolism-related pathways were the mainly enriched pathway in long-term ischemia. Taken together, this study provides novel insights into safe renal artery occlusion time in partial nephrectomy, and is of great value for elucidating molecular network characteristics and pathological features of mild to severe ischemia reperfusion kidney injury, and key genes related to metabolism and immune found in this study also provide potential diagnostic and therapeutic biomarkers for AKI.

Lysine-specific demethylase 1 aggravated oxidative stress and ferroptosis induced by renal ischemia and reperfusion injury through activation of TLR4/NOX4 pathway in mice

Acute kidney injury (AKI) is mainly caused by renal ischaemia reperfusion injury (IRI). Lots of evidence suggests that ferroptosis and oxidative stress play the vital role in renal IRI. However, the specific mechanism of renal IRI has not been fully elucidated. lysine‐specific demethylase 1 (LSD1) has been shown to regulate the pathogenesis of kidney disease. In this study, we firstly found that LSD1 was positively related to renal IRI. TCP, a classical LSD1 inhibitor, could alleviate tissue damage induced by renal IRI. Inhibition of LSD1 with either TCP or LSD1 knockdown could alleviate ferroptosis and oxidative stress caused by IRI both in vivo and in vitro. Furthermore, the results showed that suppression of LSD1 decreased the expression of TLR4/NOX4 pathway in HK‐2 cells subjected to H/R. With the si‐RNA against TLR4 or NOX4, it showed that the silence of TLR4/NOX4 reduced oxidative stress and ferroptosis in vitro. Moreover, to demonstrate the crucial role of TLR4/NOX4, TLR4 reduction, mediated by inhibition of LSD1, was compensated through delivering the adenovirus carrying TLR4 in vitro. The results showed that the compensation of TLR4 blunted the alleviation of oxidative stress and ferroptosis, induced by LSD1 inhibition. Further study showed that LSD1 activates TLR4/NOX4 pathway by reducing the enrichment of H3K9me2 in the TLR4 promoter region. In conclusion, our results demonstrated that LSD1 inhibition blocked ferroptosis and oxidative stress caused by renal IRI through the TLR4/NOX4 pathway, indicating that LSD1 could be a potential therapeutic target for renal IRI.

Inhibition of HDAC3 protects against kidney cold storage/transplantation injury and allograft dysfunction

Cold storage/rewarming is an inevitable process for kidney transplantation from deceased donors, which correlates closely with renal ischemia-reperfusion injury (IRI) and the occurrence of delayed graft function. Histone deacetylases (HDAC) are important epigenetic regulators, but their involvement in cold storage/rewarming injury in kidney transplantation is unclear. In the present study, we showed a dynamic change of HDAC3 in a mouse model of kidney cold storage followed by transplantation. We then demonstrated that the selective HDAC3 inhibitor RGFP966 could reduce acute tubular injury and cell death after prolonged cold storage with transplantation. RGFP966 also improved renal function, kidney repair and tubular integrity when the transplanted kidney became the sole life-supporting graft in the recipient mouse. In vitro, cold storage of proximal tubular cells followed by rewarming induced remarkable cell death, which was suppressed by RGFP966 or knockdown of HDAC3 with shRNA. Inhibition of HDAC3 decreased the mitochondrial pathway of apoptosis and preserved mitochondrial membrane potential. Collectively, HDAC3 plays a pathogenic role in cold storage/rewarming injury in kidney transplantation, and its inhibition may be a therapeutic option.

Prognostic factors in children with acute fulminant myocarditis receiving venoarterial extracorporeal membrane oxygenation

Background

Pediatric acute fulminant myocarditis (AFM) is a very dangerous disease that may lead to acute heart failure or even sudden death. Previous reports have identified some prognostic factors in adult AFM; however, there is no such research on children with AFM on venoarterial extracorporeal membrane oxygenation (VA-ECMO). This study aimed to find relevant prognostic factors for predicting adverse clinical outcomes.

Methods

A retrospective analysis was performed in an affiliated university children’s hospital with consecutive patients receiving VA-ECMO for AFM from July 2010 to November 2020. These children were classified into a survivor group (n=33) and a non-survivor group (n=8). Patient demographics, clinical events, laboratory findings, and electrocardiographic and echocardiographic parameters were analyzed.

Results

Peak serum creatinine (SCr) and peak creatine kinase isoenzyme MB during ECMO had joint predictive value for in-hospital mortality (p=0.011, AUC=0.962). Based on multivariable logistic regression analysis, peak SCr level during ECMO support was an independent predictor of in-hospital mortality (OR=1.035, 95% CI 1.006 to 1.064, p=0.017, AUC=0.936, with optimal cut-off value of 78 μmol/L).

Conclusion

Tissue hypoperfusion and consequent end-organ damage ultimately hampered the outcomes. The need for left atrial decompression indicated a sicker patient on ECMO and introduced additional risk for complications. Earlier and more cautious deployment would likely be associated with decreased risk of complications and mortality.

NLRP3 associated with chronic kidney disease progression after ischemia/reperfusion-induced acute kidney injury

Nod-like receptor protein 3 (NLRP3), as an inflammatory regulator, has been implicated in acute kidney injury (AKI). Failed recovery after AKI can lead to chronic kidney disease (CKD). However, the role of NLRP3 in the AKI-CKD transition is still unknown. A mild or severe AKI mouse model was performed by using ischemia-reperfusion injury (IRI). We evaluated the renal NLRP3 expression in acute and chronic phases of ischemic AKI, respectively. Although serum creatinine (Cr) and blood urea nitrogen (BUN) levels in AKI chronic phase were equivalent to normal baseline, histological analysis and fibrotic markers revealed that severe AKI-induced maladaptive tubular repair with immune cell infiltration and fibrosis. Tubular damage was restored completely in mild AKI rather than in severe AKI. Of note, persistent overexpression of NLRP3 was also found in severe AKI but not in mild AKI. In the severe AKI-induced chronic phase, there was a long-term high level of NLRP3 in serum or urine. Overt NLRP3 was mainly distributed in the abnormal tubules surrounded by inflammatory infiltrates and fibrosis, which indicated the maladaptive repair. Renal Nlrp3 overexpression was correlated with infiltrating macrophages and fibrosis. Renal NLRP3 signaling-associated genes were upregulated after severe AKI by RNA-sequencing. Furthermore, NLRP3 was found increased in renal tubular epitheliums from CKD biopsies. Together, persistent NLRP3 overexpression was associated with chronic pathological changes following AKI, which might be a new biomarker for evaluating the possibility of AKI-CKD transition.

Proximal Tubule p53 in Cold Storage/Transplantation-Associated Kidney Injury and Renal Graft Dysfunction

Kidney injury associated with cold storage/transplantation is a primary factor for delayed graft function and poor outcome of renal transplants. p53 contributes to both ischemic and nephrotoxic kidney injury, but its involvement in kidney cold storage/transplantation is unclear. Here, we report that p53 in kidney proximal tubules plays a critical role in cold storage/transplantation kidney injury and inhibition of p53 can effectively improve the histology and function of transplanted kidneys. In a mouse kidney cold storage/transplantation model, we detected p53 accumulation in proximal tubules in a cold storage time-dependent manner, which correlated with tubular injury and cell death. Pifithrin-α, a pharmacologic p53 inhibitor, could reduce acute tubular injury, apoptosis and inflammation at 24 h after cold storage/transplantation. Similar effects were shown by the ablation of p53 from proximal tubule cells. Notably, pifithrin-α also ameliorated kidney injury and improved the function of transplanted kidneys in 6 days when it became the sole life-supporting kidney in recipient mice. in vitro, cold storage followed by rewarming induced cell death in cultured proximal tubule cells, which was accompanied by p53 activation and suppressed by pifithrin-α and dominant-negative p53. Together, these results support a pathogenic role of p53 in cold storage/transplantation kidney injury and demonstrate the therapeutic potential of p53 inhibitors.

Persufflation—Current State of Play

With the ever-increasing disparity between the number of patients waiting for organ transplants and the number organs available, some patients are unable to receive life-saving transplantation in time. The present, widely-used form of preservation is proving to be incapable of maintaining organ quality during long periods of preservation and meeting the needs of an ever-changing legislative and transplantation landscape. This has led to the need for improved preservation techniques. One such technique that has been extensively researched is gaseous oxygen perfusion or Persufflation (PSF). This method discovered in the early 20th century has shown promise in providing both longer term preservation and organ reconditioning capabilities for multiple organs including the liver, kidneys, and pancreas. PSF utilises the organs own vascular network to provide oxygen to the organ tissue and maintain metabolism during preservation to avoid hypoxic damage. This review delves into the history of this technique, its multiple different approaches and uses, as well as in-depth discussion of work published in the past 15 years. Finally, we discuss exciting commercial developments which may help unlock the potential for this technique to be applied at scale.

A new mechanism for the sex differences in angiotensin II-induced hypertension: the role of macula densa NOS1β-mediated tubuloglomerular feedback

Females are protected against the development of angiotensin II (ANG II)-induced hypertension compared with males, but the mechanisms have not been completely elucidated. In the present study, we hypothesized that the effect of ANG II on the macula densa nitric oxide (NO) synthase 1β (NOS1β)-mediated tubuloglomerular feedback (TGF) mechanism is different between males and females, thereby contributing to the sexual dimorphism of ANG II-induced hypertension. We used microperfusion, micropuncture, clearance of FITC-inulin, and radio telemetry to examine the sex differences in the changes of macula densa NOS1β expression and activity, TGF response, natriuresis, and blood pressure (BP) after a 2-wk ANG II infusion in wild-type and macula densa-specific NOS1 knockout mice. In wild-type mice, ANG II induced higher expression of macula densa NOS1β, greater NO generation by the macula densa, and a lower TGF response in vitro and in vivo in females than in males; the increases of glomerular filtration rate, urine flow rate, and Na⁺ excretion in response to an acute volume expansion were significantly greater and the BP responses to ANG II were significantly less in females than in males. In contrast, these sex differences in the effects of ANG II on TGF, natriuretic response, and BP were largely diminished in knockout mice. In addition, tissue culture of human kidney biopsies (renal cortex) with ANG II resulted in a greater increase in NOS1β expression in females than in males. In conclusion, macula densa NOS1β-mediated TGF is a novel and important mechanism for the sex differences in ANG II-induced hypertension.

Acid-Base Balance Disorders During Kidney Preservation in Cold Ischemia

BACKGROUND

Acid-base balance disorders are a crucial element of ischemia-reperfusion injury during organ transplantation. Hypoxia during organ procurement and storage cause cellular homeostasis imbalance with impact on further graft function. Acidosis in preserved kidney caused by lactate accumulation may have an important role as a common denominator of various pathways leading to cellular damage.

METHODS

Our trial sought to answer questions regarding a range of pH alterations in the kidney before the transplantation, their potential cause, and how this may affect further outcome of the kidney transplantation procedure. Perfusion fluid for pH analysis was obtained from perfusion pump (PP) or through kidney flushing at the end of preservation depending on the storage method.

RESULTS

A total of 66 sample results were collated with the data from the transplant registry, hospitalization, and outpatient department. Statistical analysis was conducted linking pH results with factors related to donor, recipient, preservation, and outcome according to designed schematics. Mean perfusate pH was significantly lower in simple hypothermia (SH) vs the PP storage group (6.77 vs 7.11; P < .001). All samples of perfusate pH in the SH group were below physiological values (<7.35), and in 10% of samples in the SH group, pH >7.00.

CONCLUSIONS

We concluded that kidney storage in cold ischemia is associated with organ acidosis independent of preservation method and that SH is correlated with significantly bigger acidosis than storage in PP, which is an important procedure removing an excessive amount of hydrogen ions from kidney microcirculation, decreasing cell damage.

Protein Kinase C-δ Mediates Kidney Tubular Injury in Cold Storage-Associated Kidney Transplantation

BACKGROUND

Kidney injury associated with cold storage is a determinant of delayed graft function and the long-term outcome of transplanted kidneys, but the underlying mechanism remains elusive. We previously reported a role of protein kinase C-δ (PKCδ) in renal tubular injury during cisplatin nephrotoxicity and albumin-associated kidney injury, but whether PKCδ is involved in ischemic or transplantation-associated kidney injury is unknown.

METHODS

To investigate PKCδ's potential role in injury during cold storage-associated transplantation, we incubated rat kidney proximal tubule cells in University of Wisconsin (UW) solution at 4°C for cold storage, returning them to normal culture medium at 37°C for rewarming. We also stored kidneys from donor mice in cold UW solution for various durations, followed by transplantation into syngeneic recipient mice.

RESULTS

We observed PKCδ activation in both in vitro and in vivo models of cold-storage rewarming or transplantation. In the mouse model, PKCδ was activated and accumulated in mitochondria, where it mediated phosphorylation of a mitochondrial fission protein, dynamin-related protein 1 (Drp1), at serine 616. Drp1 activation resulted in mitochondrial fission or fragmentation, accompanied by mitochondrial damage and tubular cell death. Deficiency of PKCδ in donor kidney ameliorated Drp1 phosphorylation, mitochondrial damage, tubular cell death, and kidney injury during cold storage-associated transplantation. PKCδ deficiency also improved the repair and function of the renal graft as a life-supporting kidney. An inhibitor of PKCδ, δV1-1, protected kidneys against cold storage-associated transplantation injury.

CONCLUSIONS

These results indicate that PKCδ is a key mediator of mitochondrial damage and renal tubular injury in cold storage-associated transplantation and may be an effective therapeutic target for improving renal transplant outcomes.

Renal temperature reduction progressively favors mitochondrial ROS production over respiration in hypothermic kidney preservation

BACKGROUND

Hypothermia, leading to mitochondrial inhibition, is widely used to reduce ischemic injury during kidney preservation. However, the exact effect of hypothermic kidney preservation on mitochondrial function remains unclear.

METHODS

We evaluated mitochondrial function [i.e. oxygen consumption and production of reactive oxygen species (ROS)] in different models (porcine kidney perfusion, isolated kidney mitochondria, and HEK293 cells) at temperatures ranging 7-37 °C.

RESULTS

Lowering temperature in perfused kidneys and isolated mitochondria resulted in a rapid decrease in oxygen consumption (65% at 27 °C versus 20% at 7 °C compared to normothermic). Decreased oxygen consumption at lower temperatures was accompanied by a reduction in mitochondrial ROS production, albeit markedly less pronounced and amounting only 50% of normothermic values at 7 °C. Consequently, malondialdehyde (a marker of ROS-induced lipid peroxidation) accumulated in cold stored kidneys. Similarly, low temperature incubation of kidney cells increased lipid peroxidation, which is due to a loss of ROS scavenging in the cold.

CONCLUSIONS

Lowering of temperature highly affects mitochondrial function, resulting in a progressive discrepancy between the lowering of mitochondrial respiration and their production of ROS, explaining the deleterious effects of hypothermia in transplantation procedures. These results highlight the necessity to develop novel strategies to decrease the formation of ROS during hypothermic organ preservation.