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The increasing use of kidneys from donations after cardiac death (DCD) for renal transplantation is hindered by negative outcomes owing to organ injury after prolonged warm and cold ischemia-reperfusion. Recently, hydrogen sulfide (HWe tested a novel 30-day in vivo syngeneic murine model of DCD renal transplantation, in which the donor kidney was clamped for 30 minutes and stored for 18 hours in cold University of Wisconsin (UW) solution or UW with 150 μM sodium hydrogen sulfide (UW + NaHS) before transplantation. We also tested a 7-day in vivo porcine model of DCD renal autotransplantation, in which the left kidney was clamped for 60 minutes and preserved for 24 hours using hypothermic perfusion with UW or UW + 150 μM NaHS before autotransplantation. We collected blood and urine samples periodically, and collected kidney samples at the end point for histopathology and quantitative reverse transcription polymerase chain reaction.Rats that received HOur findings support the potential use of H

Cold ischemia-reperfusion injury (IRI) is an inevitable and unresolved problem that poses a great challenge in solid organ transplantation (SOT). It represents a major factor that increases acute tubular necrosis, decreases graft survival, and delays graft function. This complicates graft quality, post-transplant patient care and organ transplantation outcomes, and therefore undermines the success of SOT. Herein, we review recent advances in research regarding novel pharmacological strategies involving the use of different donor molecules of hydrogen sulfide (H

Thiosulfate in the form of sodium thiosulfate (STS) is a major oxidation product of hydrogen sulfide (H2S), an endogenous signaling molecule and the third member of the gasotransmitter family. STS is currently used in the clinical treatment of acute cyanide poisoning, cisplatin toxicities in cancer therapy, and calciphylaxis in dialysis patients. Burgeoning evidence show that STS has antioxidant and anti-inflammatory properties, making it a potential therapeutic candidate molecule that can target multiple molecular pathways in various diseases and drug-induced toxicities. This review discusses the biochemical and molecular pathways in the generation of STS from H2S, its clinical usefulness, and potential clinical applications, as well as the molecular mechanisms underlying these clinical applications and a future perspective in kidney transplantation.

Cold preservation is the standard of care for renal grafts. However, research on alternatives like perfusion at higher temperatures and supplementing preservation solutions with hydrogen sulfide (H2S) has gained momentum. In this study, we investigated whether adding H2S donor AP39 to porcine blood during subnormothermic perfusion at 21 °C improves renal graft outcomes. Porcine kidneys were nephrectomized after 30 min of clamping the renal pedicles and treated to 4 h of static cold storage (SCS) on ice or ex vivo subnormothermic perfusion at 21 °C with autologous blood alone (SNT) or with AP39 (SNTAP). All kidneys were reperfused ex vivo with autologous blood at 37 °C for 4 h. Urine output, histopathology and RNAseq were used to evaluate the renal graft function, injury and gene expression profiles, respectively. The SNTAP group exhibited significantly higher urine output than other groups during preservation and reperfusion, along with significantly lower apoptotic injury compared to the SCS group. The SNTAP group also exhibited differential pro-survival gene expression patterns compared to the SCS (downregulation of pro-apoptotic genes) and SNT (downregulation of hypoxia response genes) groups. Subnormothermic perfusion at 21 °C with H2S-supplemented blood improves renal graft outcomes. Further research is needed to facilitate the clinical translation of this approach.

WOS:000573472800024 PubMed: 32871814 Background: Renal cell carcinoma (RCC) is the most common cancer of the kidney. The most common histotype is clear-cell (cc) RCC. Hydrogen sulfide (H2S) is an angiogenic and anti-apoptotic gasotransmitter that is elevated under pseudohypoxic conditions. H2S is endogenously produced by three enzymes: Cystathionine gamma-lyase (CSE), cystathionine beta-synthase (CBS), and 3-mercaptopyruvate sulfurtransferase (MPST). Seeing as increased expression of these enzymes has been observed in other human cancer types, this study aimed to quantify H2S-producing enzyme expression in human RCC samples and evaluate whether it correlated with clinical outcomes. Patients and Methods: Eighty-eight human kidney tissue specimens, with healthy and cancerous tissue components, were immunohistochemically stained for CSE, CBS, and MPST. The mean pixel intensity of positively stained areas was quantified. A retrospective analysis was conducted to obtain patient demographics, rates of metastasis/recurrence, and prognostic characteristics. Statistical correlations between enzyme expressions and subsequent patient outcomes were evaluated. Results: There was significantly greater expression of CSE, CBS, and MPST in cc-RCC compared to paired healthy tissue (p

Heart transplant has been accepted as the standard treatment for end-stage heart failure. Because of its susceptibility to ischemia-reperfusion injury, the heart can be preserved for only 4 to 6 hours in cold static preservation solutions. Prolonged ischemia time is adversely associated with primary graft function and long-term survival. New strategies to preserve donor hearts are urgently needed. We demonstrate that AP39, a mitochondria-targeting hydrogen sulfide donor, significantly increases cardiomyocyte viability and reduces cell apoptosis/death after cold hypoxia/reoxygenation in vitro. It also decreases gene expression of proinflammatory cytokines and preserves mitochondria function. Using an in vivo murine heart transplant model, we show that preserving donor hearts with AP39-supplemented University of Wisconsin solution (n = 7) significantly protects heart graft function, measured by quantitative ultrasound scan, against prolonged cold ischemia-reperfusion injury (24 hours at 4°C), along with reducing tissue injury and fibrosis. Our study demonstrates that supplementing preservation solution with AP39 protects cardiac grafts from prolonged ischemia, highlighting its therapeutic potential in preventing ischemia-reperfusion injury in heart transplant.

Hydrogen sulfide (H2S) is the latest member of the gasotransmitter family and known to play essential roles in cancer pathophysiology. H2S is produced endogenously and can be administered exogenously. Recent studies showed that H2S in cancers has both pro- and antitumor roles. Understanding the difference in the expression and localization of tissue-specific H2S-producing enzymes in healthy and cancer tissues allows us to develop tools for cancer diagnosis and treatment. Urological malignancies are some of the most common cancers in both men and women, and their early detection is vital since advanced cancers are recurrent, metastatic, and often resistant to treatment. This review summarizes the roles of H2S in cancer and looks at current studies investigating H2S activity and expression of H2S-producing enzymes in urinary cancers. We specifically focused on urothelial carcinoma, renal cell carcinoma, and prostate cancer, as they form the majority of newly diagnosed urinary cancers. Recent studies show that besides the physiological activity of H2S in cancer cells, there are patterns between the development and prognosis of urinary cancers and the expression of H2S-producing enzymes and indirectly the H2S levels. Though controversial and not completely understood, studying the expression of H2S-producing enzymes in cancer tissue may represent an avenue for novel diagnostic and therapeutic strategies for addressing urological malignancies.

Renal transplantation is the preferred treatment for end-stage renal disease. Currently, there is a large gap between the supply and demand for transplantable kidneys. The use of sub-optimal grafts obtained via donation after cardiac death (DCD) is on the rise. While static cold storage (SCS) in University of Wisconsin (UW) solution on ice (4 degrees C) is the clinical standard of care for renal graft preservation, cold storage has been associated with negative graft outcomes. The alternative, normothermic machine perfusion, involves mechanical perfusion of the organ at physiological or normothermic temperature (37 degrees C) and this technique is expensive, complicated and globally inaccessible. As such, simpler alternatives are of interest. Preliminary results revealed that UW solution is more protective at 21 degrees C than 37 degrees C and subnormothermic preservation is of interest because it may facilitate the use of existing solutions while preventing cold injury. We have previously shown that SCS in UW solution supplemented with mitochondria-targeted H2S donor AP39 improves renal graft outcomes. As such, it was hypothesized subnormothermic preservation at 21 degrees C with AP39 will also improve renal outcomes. Using an in vitro model of hypoxia and reoxygenation, we found that treating porcine tubular epithelial cells with UW + 5 mu M AP39 during 18 h hypoxia at 21 degrees C significantly increased renal tubular epithelial cell viability after 24 h of reoxygenation at 37 degrees C compared to UW alone. Also, AP39-supplemented UW solution was significantly more cytoprotective during hypoxia at 21 degrees C than hypoxia at 37 degrees C, regardless of AP39 concentration. Using an ex vivo DCD organ preservation model, we found that DCD porcine kidneys stored for 24 h in UW + 200 nM AP39 at 21 degrees C showed significantly lower tissue necrosis than DCD porcine kidneys preserved using SCS in UW solution, the clinical standard of care. Overall, our findings suggest that exogenous H2S supplementation improves the viability of the gold standard organ preservation solution, UW solution, for subnormothermic preservation at 21 degrees C.

Renal transplantation is the preferred treatment for end-stage renal disease. Currently, there is a large gap between the supply and demand for transplantable kidneys. The use of sub-optimal grafts obtained via donation after cardiac death (DCD) is on the rise. While static cold storage (SCS) in University of Wisconsin (UW) solution on ice (4°C) is the clinical standard of care for renal graft preservation, cold storage has been associated with negative graft outcomes. The alternative, normothermic machine perfusion, involves mechanical perfusion of the organ at physiological or normothermic temperature (37°C) and this technique is expensive, complicated and globally inaccessible. As such, simpler alternatives are of interest. Preliminary results revealed that UW solution is more protective at 21°C than 37°C and subnormothermic preservation is of interest because it may facilitate the use of existing solutions while preventing cold injury. We have previously shown that SCS in UW solution supplemented with mitochondria-targeted H

In prolonged complete unilateral ureteral obstruction, reduced renal blood flow places the kidney in a state of ischemia, which can cause tubular injury and inflammation. Infiltrating inflammatory cells release transforming growth factor beta 1, which is a cytokine that initiates fibrosis through the epithelial-mesenchymal-transition pathway. Persistent fibrosis can lead to irreversible renal injury and loss of function. While surgical intervention can remove the obstruction, relief of obstruction may not fully reverse renal injury. Additionally, patients often encounter long wait-times between initial consultation and medical intervention, resulting in the accumulation of renal injury that may cause permanent dysfunction. Currently, accepted pharmacological therapies to mitigate the symptoms of ureteral obstruction include acetaminophen, cyclooxygenase-inhibitors, non-steroidal anti-inflammatory medications, opioids and alpha-receptor blockers. However, there is no evidence that they mitigate renal injury. Therefore, identifying potential therapies that could be administered during obstruction may help to improve renal function following decompression. Evidence suggests that endogenously produced gasotransmitters can exhibit anti-inflammatory and antioxidant effects. Nitric oxide, carbon monoxide, and hydrogen sulfide have been identified as gasotransmitters and have been shown to have cytoprotective effects in various models of tissue injury. Studies have shown that treatment with sodium hydrogen sulfide (a hydrogen sulfide donor salt) mitigated transforming growth factor beta 1 expression, oxidative stress, fibrosis, and inflammation associated with urinary obstruction. More recently, the use of more directed hydrogen sulfide donor molecules, such as GYY4137, has led to significant decreases in inflammation, fibrosis, and expression of epithelial mesenchymal transition markers following urinary obstruction. Taken together, these findings suggest that hydrogen sulfide may be a novel potential therapy against renal injury caused by urinary obstruction. This review will highlight the existing literature about the pathogenesis and treatment of renal damage caused by chronic urinary obstruction and propose novel upcoming strategies that could improve patient outcomes.