Renal Ischemia-reperfusion Injury In Rats Research Articles

#348 Neutrophil membrane-derived nanovesicles deliver IL-37 to repair renal endothelial cells in ischemia‒reperfusion injury

Abstract Background and Aims Renal ischemia‒reperfusion injury (IRI) is one of the most important causes of acute kidney injury (AKI). Interleukin (IL)-37 is a novel anti-inflammatory factor, but its application is still limited by its low stability and delivery efficiency. In recent years, engineered extracellular vesicles (EVs) have attracted substantial attention as an emerging drug delivery system. The aim of this study was to investigate the reparative effect of neutrophil membranes-derived nanovesicle (N-MV)-delivered IL-37 on renal IRI and its mechanism of action. Method The density gradient centrifugation method was used to extract peripheral blood neutrophils from rats, and the differential centrifugation method was used to extract neutrophil membranes. Cell membranes and IL-37 were then extruded with polycarbonate porous membranes with different pore sizes using a mini extruder to prepare IL-37 that was coated with neutrophil membrane (N-MV@IL-37). Subsequently, the physical and chemical properties and in vitro biological functions were identified. The in vivo distribution of N-MV@IL-37 as well as the renal function and inflammatory response in rats were further evaluated in a rat renal IRI model, and the targeting and anti-inflammatory mechanisms of N-MV@IL-37 were further explored. Results N-MV@IL-37 not only enhanced the stability of IL-37 but also targeted endothelial cells via P-selectin glycoprotein ligand-1 (PSGL-1) on neutrophil membrane surfaces. In vitro experiments showed that N-MV@IL-37 inhibited endothelial cell apoptosis and inflammatory factor production and promoted endothelial cell viability and angiogenesis. In the rat renal IRI model, N-MV@IL-37 inhibited renal cell apoptosis and alleviated inflammatory responses, thereby improving renal function in IRI rats. Conclusion N-MVs provide an effective method of delivering IL-37, thereby alleviating the inflammatory response due to renal IRI and repairing renal endothelial cells; these vesicles could be a potential system for the treatment of renal IRI. Meanwhile, N-MVs also provided a drug delivery platform to provide a new strategy for the treatment of other IRI-like diseases.

Modified EBP-bFGF targeting endogenous renal extracellular matrix protects against renal ischemia-reperfusion injury in rats.

Acute kidney injury (AKI) is a life-threatening disease primarily caused by renal ischemia-reperfusion (I/R) injury, which can result in renal failure. Currently, growth factor therapy is considered a promising and effective approach for AKI treatment. Basic fibroblast growth factor (bFGF), an angiogenic factor with potent activity, efficiently stimulates angiogenesis and facilitates regeneration of renal tissue. However, the unrestricted diffusion of bFGF restricts its clinical application in AKI treatment. Therefore, developing a novel sustained released system for bFGF could enhance its potential in treating AKI. In this study, we genetically engineered a multifunctional recombinant protein by fusing bFGF with a specific peptide (EBP). EBP-bFGF effectively binds to the extracellular matrix in the injured kidney, enabling slow release of bFGF in AKI. Furthermore, following orthotopic injection into I/R rats' ischemic kidneys, EBP-bFGF exhibited stable retention within the tissue. Additionally, EBP-bFGF suppressed apoptosis of renal cells, reduced renal fibrosis, and facilitated recovery of renal function. These findings suggest that EBP-bFGF delivery system represents a promising strategy for treating AKI.

Role of cAMP/pCREB and GSK-3β/NF-κB p65 signaling pathways in the renoprotective effect of mirabegron against renal ischemia-reperfusion injury in rats

Acute kidney injury and other renal disorders are thought to be primarily caused by renal ischemia-reperfusion (RIR). Cyclic adenosine monophosphate (cAMP) has plenty of physiological pleiotropic effects and preserves tissue integrity and functions. This research aimed to examine the potential protective effects of the β3-adrenergic receptors agonist mirabegron in a rat model of RIR and its underlying mechanisms. Male rats enrolled in this work were given an oral dose of 30 mg/kg mirabegron for two days before surgical induction of RIR. Renal levels of kidney injury molecule-1 (KIM-1), monocyte chemoattractant protein-1 (MCP-1), tumor necrosis factor-alpha (TNF-α), Interleukin-10 (IL-10), cAMP, cAMP-responsive element binding protein (pCREB), and glycogen synthase kinase-3 beta (GSK-3β) were assessed along with blood urea nitrogen and serum creatinine. Additionally, caspase-3 and nuclear factor-kappa B (NF-κB) p65 were explored by immunohistochemical analysis. Renal specimens were inspected for histopathological changes. RIR led to renal tissue damage with elevated blood urea nitrogen and serum creatinine levels. The renal KIM-1, MCP-1, TNF-α, and GSK-3β were significantly increased, while IL-10, cAMP, and pCREB levels were reduced. Moreover, upregulation of caspase-3 and NF-κB p65 protein expression was seen in RIR rats. Mirabegron significantly reduced kidney dysfunction, histological abnormalities, inflammation, and apoptosis in the rat renal tissues. Mechanistically, mirabegron mediated these effects via modulation of cAMP/pCREB and GSK-3β/NF-κB p65 signaling pathways. Mirabegron administration could protect renal tissue and maintain renal function against RIR.

The potential renoprotective effect of Raloxifene in renal ischemia-reperfusion injury in a male rat model.

Renal ischemia-reperfusion injury is caused by a temporary reduction in oxygen-carrying blood flow to the kidney, followed by reperfusion. During ischemia, kidney tissue damage induces overproduction of reactive oxygen species, which produces oxidative stress. The blood flow restoration during the reperfusion period causes further production of reactive oxygen species that ends with apoptosis and cell death. This study aimed to investigate the potential renoprotective effects of Raloxifene on bilateral renal ischemia-reperfusion injury in rats by looking into kidney function biomarkers, urea and creatinine, inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β). Additionally, antioxidant markers such as total antioxidant capacity (TAC) and the pro-apoptotic marker caspase-3 were assessed. Histopathological scores were also employed for evaluation. Our experimental design involved 20 rats divided into four groups: the sham group underwent median laparotomy without ischemia induction, the control group experienced bilateral renal ischemia for 30 minutes followed by 2 hours of reperfusion, the vehicle group received pretreatment with a mixture of corn oil and dimethyl sulfoxide (DMSO) before ischemia induction, and the Raloxifene-treated group was administered Raloxifene at a dose of 10 mg/kg before ischemia induction, followed by ischemia-reperfusion. Urea and creatinine, TNF-α, IL-1β, and caspase-3 in the Raloxifene group were significantly lower compared to the control and vehicle groups. On the other hand, TAC levels in the Raloxifene group were significantly higher than in the control and vehicle groups. This study concluded that Raloxifene had a renoprotective impact via multiple actions as an anti-inflammatory, anti-apoptotic, and antioxidant agent.

Role of Iberin as an anti-apoptotic agent on renal ischemia-reperfusion injury in rats.

Ischemia-reperfusion injury (IRI) is a major contributor to acute and chronic kidney failure, heart failure, and ischemic stroke. This study aimed to investigate the therapeutic potential of Iberin, known for its anti-inflammatory, antioxidant, and antiapoptotic properties, in a rat model of renal IRI. Twenty-four adult male rats were randomly divided into four groups: Group I (Sham group) underwent laparotomy without IRI induction; Group II (Control group) underwent laparotomy followed by renal artery clamping for 30 minutes to induce ischemia, followed by 2 hours of reperfusion; Group III (Iberin treatment group) received a pre-injection of Iberin (15 mg/kg) and underwent 30 minutes of ischemia followed by 2 hours of reperfusion; and Group IV (Vehicle-treated group) received the vehicle (ethanol) 1 hour prior to ischemia and reperfusion induction. Iberin was diluted with ethanol. Biomarkers associated with inflammation, oxidative stress, and apoptosis were measured using enzyme-linked immunosorbent assay. Iberin treatment significantly reduced levels of inflammatory cytokines interleukin-1β (IL-1β) and IL-6, Bcl-2-associated X protein (BAX), tumor necrosis factor α (TNF-α), nuclear factor kappa p56, high mobility group B1, and neutrophil gelatinase-associated lipocalin. Moreover, Iberin increased levels of heat shock protein and Bcl2 compared to the control and vehicle groups. Iberin treatment prolonged the ischemic tolerance of renal tissue, potentially preventing or delaying irreversible injuries. These findings highlight the potential of Iberin as a promising candidate for mitigating renal injury caused by ischemia-reperfusion, due to its ability to modulate inflammatory markers.

Role of p38 MAPK, Akt and NFκB in renoprotective effects of nebivolol on renal ischemia-reperfusion injury in rats

ABSTRACT Renal ischemia-reperfusion (I-R) injury is a complex pathophysiologic condition characterized by oxidative stress, inflammation and apoptosis. We investigated the potential renoprotective effect of nebivolol, a β1 adrenergic receptor blocker, against renal I-R injury. We focused on the role of nebivolol in activating p38 mitogen-activated protein kinase (MAPK) signaling, Akt (protein kinase B) and nuclear factor-κB (NFκB) transcription factors, which contribute to oxidative stress, inflammation and apoptosis during renal I-R. We divided 20 adult male Wistar albino rats into three experimental groups. Group 1 was a sham control in which only laparotomy was performed. Group 2 was the I-R group in which both kidneys were made ischemic for 45 min, then reperfused for 24 h. Group 3 was the I-R + nebivolol group in which 10 mg/kg nebivolol was administrated by gavage for 7 days before I-R. We measured Inflammation, oxidative stress and active caspase-3 as well as activation of p38 MAPK, Akt (protein kinase B) and NFκB transcription factor. Nebivolol significantly reduced oxidative stress and increased superoxide dismutase levels during renal I-R. We found that nebivolol significantly decreased interstitial inflammation, and TNF-α and interleukin-1β mRNA expression. Nebivolol significantly reduced active caspase-3 and kidney injury molecule-1 (KIM-1) expressions. Nebivolol also significantly decreased activation of p38 MAPK signaling and NFκB, and induced Akt activation during renal I-R. Our findings suggest that nebivolol may be useful for management of renal I-R injury.

The effect of JQ1 systemic administration on oxidative stress and apoptotic markers in renal ischemic reperfusion injury in a rat model.

This study aimed to investigate the effects of JQ1 in a renal ischemia-reperfusion (IR) rat model. Twenty-four adult male Wistar Albino rats were randomly divided into four equal groups. The sham group underwent laparotomy without ischemia-reperfusion induction. The control group experienced bilateral renal ischemia for 30 minutes, followed by a 2-hour reperfusion period. The vehicle group (IR group + DMSO) and JQ1 group (same as in control IR + 25 mg/kg JQ1). Kidney and blood samples were collected 2 hours after reperfusion. Blood samples were used to analyze serum creatinine and blood urea nitrogen levels. Renal tissue was assessed for TNF-alpha, caspase-3, FOXO4, PI3K/AKT signaling pathway, and histological analysis. The control group exhibited significantly higher serum creatinine, blood urea nitrogen, caspase-3, TNF-alpha, and FOXO4 levels in renal tissue compared to the sham group. Additionally, the PI3K/AKT signaling pathway was significantly decreased in the control group. Histopathological examination revealed severe kidney damage in the control group compared to the sham group. In rats treated with JQ1, serum creatinine, BUN, caspase-3, TNF-alpha, and FOXO4 levels in renal tissue significantly improved. The PI3K/AKT signaling pathway was substantially increased (p-value 0.01) compared to the Vehicle and Control groups. The tubular severity score was also significantly reduced in the JQ1-treated groups compared to the Control and Vehicle groups. In conclusion, JQ1 significantly ameliorated renal ischemia-reperfusion injury in rats by suppressing apoptosis and inflammatory pathways.

Protective effect of IAXO-102 on renal ischemia-reperfusion injury in rats.

Ischemia/reperfusion injury (IRI) is a common cause of kidney damage, characterized by oxidative stress and inflammation. In this study, we investigated the potential protective effects of IAXO-102, a chemical compound, on experimentally induced IRI in male rats. The bilateral renal IRI model was used, with 24 adult male rats randomly divided into four groups (N=6): sham group (laparotomy without IRI induction), control group (laparotomy plus bilateral IRI for 30 minutes followed by 2 hours of reperfusion), vehicle group (same as control but pre-injected with the vehicle), and treatment group (similar to control but pre-injected with IAXO-102). We measured several biomarkers involved in IRI pathophysiology using enzyme-linked immunosorbent assay (ELISA), including High mobility group box1 (HMGB1), nuclear factor kappa b-p65 (NF-κB p65), interleukin beta-1 (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), 8-isoprostane, Bcl-2 associated X protein (BAX), heat shock protein 27 (HSP27), and Bcl-2. Statistical analysis was performed using one-way ANOVA and Tukey post hoc tests. Our results showed that IAXO-102 significantly improved kidney function, reduced histological alterations, and decreased the inflammatory response (IL-1, IL-6, and TNF) caused by IRI. IAXO-102 also decreased apoptosis by reducing pro-apoptotic Bax and increasing anti-apoptotic Bcl-2 without impacting HSP27. In conclusion, our findings suggest that IAXO-102 had a significant protective effect against IRI damage in the kidneys.

PD31-06 THE EFFECT OF KIDNEY PRESERVATION AT 10°C WITH HEMOPURE AND HYDROGEN SULFIDE DONOR, SODIUM THIOSULFATE, IN A SYNGENEIC RAT RENAL TRANSPLANTATION MODEL

You have accessJournal of UrologyCME1 Apr 2023PD31-06 THE EFFECT OF KIDNEY PRESERVATION AT 10°C WITH HEMOPURE AND HYDROGEN SULFIDE DONOR, SODIUM THIOSULFATE, IN A SYNGENEIC RAT RENAL TRANSPLANTATION MODEL Maria Abou Taka and Alp Sener Maria Abou TakaMaria Abou Taka More articles by this author and Alp SenerAlp Sener More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003324.06AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Renal transplantation is the preferred treatment for patients with end-stage renal disease. Yet, donor kidney demand outweighs supply. Static cold storage (SCS) at 4°C is the current gold standard for renal preservation. SCS contributes to kidney damage through renal ischemia-reperfusion injury (IRI) that involves cellular death and inflammation. In porcine models of renal transplantation, we added non-FDA-approved hydrogen sulfide (H2S) donor, AP39, to a bovine-based blood substitute, Hemopure, at 21°C and 37°C, which improved renal graft quality; though, the experimental setup was costly to meet renal metabolic demand. In rats, we investigated sodium thiosulfate (STS), an FDA-approved H2S donor, at 4°C and observed similar benefits. However, there is still a risk of 4°C cold IRI. Recent studies showed that 10°C human organ graft preservation enhanced patient survival without requiring extensive oxygen during preservation. Therefore, we hypothesize that preservation solutions with STS and Hemopure at 10°C will reduce renal IRI compared to SCS. METHODS: Using an in vitro model of rat renal IRI, we evaluated STS use at 4°C, 10°C, 21°C, and 37°C. We treated rat proximal tubular epithelial cells with 150 µM STS for 24 hours in hypoxic conditions to mimic ischemia, and 24 hours in normoxic conditions to mimic reperfusion. To assess cellular viability, we used flow cytometry and stained cells with FITC-Annexin-V and PerCP-Propidium Iodide to determine apoptosis and necrosis levels, respectively. RESULTS: STS treatment significantly enhanced cellular viability at 10°C compared to 4°C, 21°C, and 37°C, as determined by the percentage of cells negatively stained with FITC-Annexin-V and PerCP-Propidium Iodide. STS treatment also significantly decreased apoptotic and necrotic cells at 10°C compared to 4°C, 21°C, and 37°C, as shown by the percentage of cells positively stained with FITC-Annexin-V and PerCP-Propidium Iodide. CONCLUSIONS: Overall, 10°C STS treatment significantly protects rat proximal tubular epithelial cells from IRI, suggesting that 10°C kidney preservation may enhance renal graft survival, especially in a cost-effective manner, compared to other preservation temperatures currently used in transplantation. Source of Funding: Ontario Graduate Scholarship, Department of Surgery Internal Research Funds, Lawson Internal Research Fund © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e902 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Maria Abou Taka More articles by this author Alp Sener More articles by this author Expand All Advertisement PDF downloadLoading ...

Impact of combined ischemic preconditioning and melatonin on renal ischemia-reperfusion injury in rats.

Studying the effect of melatonin pretreatment and ischemic preconditioning on renal ischemia-reperfusion injury (IRI). Forty-eight Wistar rats were randomized into six groups: control, sham operation, IRI (IRI in left kidney + right nephrectomy), IRI+ischemic preconditioning, IRI+Melatonin, and IRI+ischemic preconditioning+Melatonin groups. Melatonin (10 mg/kg) was intraperitoneally injected for 4 weeks before renal IRI. Ischemic preconditioning was performed by three cycles of 2 min-ischemia followed by 5 min-reperfusion period. A right nephrectomy was initially done and the left renal artery was clamped for 45 min. After 24 hr of ischemia-reperfusion, rats were decapitated. Kidney tissue samples were taken for histopathological assessment and the determination of kidney proinflammatory and anti-inflammatory cytokines, apoptotic protein caspase-3, oxidative stress markers, and activities of antioxidant enzymes. Serum creatinine and blood urea nitrogen (BUN) concentrations were measured for evaluation of renal function. Renal IRI animals showed increased levels of creatinine, BUN, tumor necrosis factor-α (TNF-α), caspase-3, total nitrite/nitrate, and malondialdehyde (MDA), and decreased levels of interleukin-13 (IL-13), and activities of glutathione peroxidase (GPx) and superoxide dismutase (SOD). Melatonin pretreatment or ischemic preconditioning resulted in decreased creatinine, BUN, TNF-α, caspase-3, nitrite/nitrate, and MDA, and increased IL-13, GPx, and SOD, with improved histopathological changes. Combined melatonin and ischemic preconditioning showed more effective improvement in renal IRI changes rather than melatonin or ischemic preconditioning alone. Combined melatonin and ischemic preconditioning have better beneficial effects on renal IRI than applying each one alone.

Azilsartan Modulates HMGB1/NF-κB/p38/ERK1/2/JNK and Apoptosis Pathways during Renal Ischemia Reperfusion Injury

Renal ischemia/reperfusion (IR) injury is characterized by an unexpected impairment of blood flow to the kidney. Azilsartan is an angiotensin receptor blocker that is approved for the management of hypertension. The present study aimed to investigate, on molecular basics, the nephroprotective activity of azilsartan on renal IR injury in rats. Rats were assigned into four groups: (1) Sham group, (2) Azilsartan group, (3) IR group, and (4) IR/Azilsartan-treated group. Histological examination and renal function were evaluated. Levels of KIM-1, HMGB1, caspase 3, GPX, SOD, NF-κB, and p53 proteins were investigated using ELISA. mRNA levels of IL-1β, IL6, IL10, TNF-α, NF-κB, p53, and bax were assessed by qRT-PCR. Expression of p38, JNK, and ERK1/2 proteins was investigated by Western blotting. IR injury resulted in tissue damage, elevation of creatinine, BUN, KIM-1, HMGB1, caspase 3, NF-κB, and p53 levels, decreasing GPX and SOD activities, and up-regulation of NF-κB, IL-1β, IL6, TNF-α, p53, and bax genes. Furthermore, it up-regulated the expression of phosphorylated/total ratio of p38, ERK1/2, and JNK proteins. Interestingly, treatment of the injured rats with azilsartan significantly alleviated IR injury-induced histopathological and biochemical changes. It reduced the creatinine, BUN, KIM-1, HMGB1, caspase-3, NF-κB, and p53 levels, elevated GPX and SOD activities, down-regulated the expression of NF-κB, IL-1β, IL6, TNF-α, p53, and bax genes, and up-regulated IL10 gene expression. Furthermore, it decreased the phosphorylated/total ratio of p38, ERK1/2, and JNK proteins. Azilsartan exhibited nephroprotective activity in IR-injured rats via its antioxidant effect, suppression of inflammation, attenuation of apoptosis, and inhibition of HMGB1/NF-κB/p38/ERK1/2/JNK signaling pathway.

Costunolide prevents renal ischemia-reperfusion injury in rats by reducing autophagy, apoptosis, inflammation, and DNA damage.

Renal ischemia-reperfusion (I/R) is a vital health condition leading to acute kidney injury. Costunolide (COST) is an actively used molecule clinically for its anti-inflammatory, antioxidant, and immunomodulatory properties. In the present study, we searched for the possible protective effects of COST against renal ischemia/reperfusion (I/R) injury in rats. We established a renal I/R rat model. We divided forty rats into four groups: group I (sham), group II (I/R), group III (I/R+COST 5 mg/kg), and group IV (I/R+COST 10 mg/kg). We collected blood, kidney, and lung samples for analysis. COST administration performed anti-oxidant and anti-inflammatory activity by reducing oxidant parameters and proinflammatory cytokine levels. COST alleviated DNA damage through declining 8-hydroxydeoxyguanosine (8-OHdG) levels. In addition, COST diminished tubular damage and inflammation by reducing kidney injury molecule-1 (KIM-1) production. COST administration also ameliorated apoptosis and autophagy by decreasing caspase-3 and microtubule-associated protein light chain 3B (MAPLC3, LC3B) expression. COST demonstrated protective effects against renal I/R-induced injury.

The effects of tarantula cubensis extract on renal ischemia reperfusion injury in rats.

Renal ischemia-reperfusion (IR) related acute kidney injury (AKI) is an important health problem and has not yet been fully treated. Tarantula cubensis extract (TCE) is a homeopathic drug that has antiinflammatory and antioxidant effects. This study aimed to investigate the effects of TCE on renal ischemia-reperfusion injury in rats. This study was carried out on 48 Spraque-Dawley male rats, which were divided into six groups. The first, second, and third groups were control, sham, and IR groups, respectively. Group four received IR and 0.2 mL of 96% ethanol. Group five and six received ischemia and reperfusion and TCE 0.01 and 0.1 mg per rat (which correspond to approximately 0.04 mg/kg, and 0.4 mg/kg), respectively. Tumor necrosis factor alpha (TNF-α), interleukin-1beta (IL-1β), total antioxidant status (TAS), and total oxidant status (TOS) levels in renal tissue were measured by enzyme-linked immunosorbent assay (ELISA). Oxidative stress index (OSI) was obtained by proportioning TAS and TOS. Superoxide dismutase (SOD), myeloperoxidase (MPO) activities, and malondialdehyde (MDA) levels were determined by manual spectrophotometric methods. The histopathological changes were evaluated via hematoxylineosin and immunohistochemical staining. In IR group, renal tissue TNF-α and IL-1β levels were significantly higher than control group (p < 0.0001 for both), and low(p < 0.0001 for both) and high dose (p < 0.0001 for both) TCE administration decreased these markers. Low and high doses of TCE decreased OSI values compared with IR group (p = 0.04 and p = 0.001 respectively). Although TCE decreased MDA levels, it was not statistically significant. MPO levels significantly decreased. In addition, TCE has been found to prevent hemorrhage, cast formation, and dilatation caused by IR in renal tissues stained with hematoxylin-eosin. And also, the most intense nuclear factor kappa B (NFκB) and caspase-3 immunopositivity found in IR group was decreased in both of the TCE groups. Although TCE showed a protective effect by inhibiting inflammation against IR damage in renal tissues, there was no clear effect on oxidative stress. Larger and more detailed studies are needed to clarify the issue.

Sevoflurane participates in the protection of rat renal ischemia-reperfusion injury by down-regulating the expression of TRPM7.

To investigate the protective effect of sevoflurane preconditioning on renal ischemia-reperfusion injury (renalischemiareperfusionmodel, RIRI) and its related mechanism. Eighty healthy adult male SD rats were randomly divided into control group (Sham group), model group (RIRI group), sevoflurane pretreatment group (Sev group) and TRPM7 inhibitor combined with sevoflurane pretreatment group (T + Sev group), 20 animals in each group. Hematoxylin-eosin (HE) staining was used to observe the pathological changes of renal tissue, and the levels of creatinine and urea nitrogen in each group were detected. Deoxyribonucleic acid terminal transferase-mediated dUTP nick end labeling (TUNEL) assay was used to detect renal cell apoptosis, and Western blottingwas used to detect the expression of apoptotic proteins cleaved-caspase-3, bax, Bcl-2, and TRPM7 in renal tissue; Detection of oxidative stress-related index levels in renal tissue and levels of inflammatory factors in renal tissue and serum. Compared with the Sham group, the renal tissue pathological damage was aggravated, the levels of creatinine and blood urea nitrogen were increased, and the apoptosis was increased in the RIR group and the Sev group. Death, malondialdehyde (MDA) levels and inflammatory factors were increased, and superoxide dismutase (SOD) levels were decreased (all p < .05); The scores, apoptosis rate, MDA level, and relative expression of inflammatory factor levels were decreased, and SOD levels were increased (all p < .05). Compared with the Sev group, the renal tissue pathological damage in the T + Sev group was aggravated, creatinine, blood urea nitrogen levels increased, apoptosis increased, apoptosis-related proteins cleaved-caspase-3, bax, Bcl-2 showed increased apoptosis, malondialdehyde (MDA) levels, inflammatory factor levels increased, ultrahigh The levels of oxide dismutase (SOD) were decreased (all p < .05). Therefore, we believe that sevoflurane is involved in the protection of rat renal ischemia-reperfusion injury by downregulating the expression of TRPM7.

USP7 accelerates FMR1-mediated ferroptosis by facilitating TBK1 ubiquitination and DNMT1 deubiquitination after renal ischemia-reperfusion injury.

Renal ischemia/reperfusion (I/R) leads to acute kidney injury and is associated with cell ferroptosis, an oxidative programmed cell death. This study aims to explore whether USP7 regulates ferroptosis in rat kidneys suffered I/R and the underlying mechanisms. Human renal tubular epithelial cells HK-2 were treated with hypoxia/reoxygenation (H/R) to establish a cell model. The expression of ubiquitin specific peptidase 7 (USP7) in H/R-treated cells was determined. USP7 siRNA was transfected into H/R-treated cells, followed by the detection of cell proliferation, iron ion concentration, oxidative stress levels and glutathione peroxidase 4 (GPX4) and solute carrier family 7-member 11 (SLC7A11) protein levels. Western blotting and immunoprecipitation analyses were performed to detect the effects of USP7 on the ubiquitination of TANK-binding kinase 1 (TBK1) and DNA methyltransferase 1 (DNMT1). Then, H/R-treated cells were transfected with USP7 siRNA alone or together with TBK1 siRNA. Co-immunoprecipitation was used to detect binding relationship between TBK1 and FMRP translational regulator 1 (FMR1). The level of DNMT1 and methylation ratio of the FMR1 promoter region were determined with chromatin immunoprecipitation and methylation specific PCR assays, respectively. Furthermore, USP7 siRNA and FMR1 siRNA were transfected alone or together into H/R-treated cells, followed by the detection of cell functions. An I/R rat model was constructed to analyze the effects of USP7 on renal function in rats. USP7 was significantly upregulated in H/R-treated cells. USP7 interference markedly increased HK-2 cell proliferation and the protein levels of GPX4 and SLC7A11, restrained the iron ion concentration, and ameliorated oxidative stress. USP7 promoted TRIM27-mediated TBK1 ubiquitination and degradation. USP7 inhibition resulted in increased ubiquitination and decreased stability of DNMT1. USP7 was able to recruit DNMT1 to the FMR1 promoter region, which increased promoter methylation rates and suppressed FMR1 expression. TBK1 or FMR1 overexpression could reverse the effects of USP7 on cell functions. Inhibition of USP7 alleviated renal ischemia-reperfusion injury in rats. USP7 inhibition attenuated I/R-induced renal injury by inhibiting ferroptosis through decreasing ubiquitination of TBK1 and promoting DNMT1-mediated methylation of FMR1.

MP36-19 PROSTACYCLIN (TREPROSTINIL) THERAPY IMPROVES RENAL HEMODYNAMICS DURING RAT RENAL ISCHEMIA-REPERFUSION INJURY

You have accessJournal of UrologyCME1 May 2022MP36-19 PROSTACYCLIN (TREPROSTINIL) THERAPY IMPROVES RENAL HEMODYNAMICS DURING RAT RENAL ISCHEMIA-REPERFUSION INJURY Frances Kazal, Meiwen Ding, Dicken Ko, Reginald Gohh, and Nisanne Ghonem Frances KazalFrances Kazal More articles by this author , Meiwen DingMeiwen Ding More articles by this author , Dicken KoDicken Ko More articles by this author , Reginald GohhReginald Gohh More articles by this author , and Nisanne GhonemNisanne Ghonem More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002590.19AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Renal ischemia-reperfusion injury (IRI) is a crucial factor causing acute kidney injury (AKI). To date, no pharmacological treatments are available for the prevention of I/R-induced renal injury. Here, we investigate the renal hemodynamics and reno-protective effects of the prostacyclin analog, treprostinil, against renal IRI in vivo. METHODS: Male Sprague Dawley rats were subjected to bilateral renal ischemia (45 minutes) followed by reperfusion (1–48 hour). Treprostinil (100 ng/kg/min) was administered subcutaneously either (A) at the time of ischemia (IRI-immT) or (B) approximately 18-24 hours before renal IRI (IRI-preT). RESULTS: Serum and urine creatinine were elevated at 24 hours post-reperfusion in the IRI group vs. sham (P <0.001), which both the IRI-immT and IRI-preT reduced the peak of serum creatinine at 24 hours after renal IRI (P <0.001). Also, medullary and cortical renal blood flow (RBF) were significantly reduced in the IRI group vs. sham (P <0.001), whereas the IRI-immT (P <0.01) and IRI-preT (P <0.05) groups improved RBF at 90 minutes post-reperfusion and maintained throughout 120 minutes. In parallel, animals in the IRI injury group experienced a decreased eGFR, increased urinary sodium (UNa 2+) excretion and proteinuria during the first 24 hours post-reperfusion vs. sham (P <0.01). Meanwhile, treprostinil reduced the UNa 2+ and proteinuria and completely restored the eGRF to baseline by 48 hours post-reperfusion and, compared to the IRI group (P <0.01). CONCLUSIONS: This study demonstrates the efficacy of treprostinil in improving renal hemodynamics and kidney function early post-IRI in a clinically relevant rat model of AKI. Specifically, our data show that treprostinil remarkably increased renal blood flow and GFR, and reduced sodium excretion and proteinuria post-reperfusion. Importantly, these data suggest that treprostinil has the potential to serve as a therapeutic agent to protect the kidney against renal IRI. Source of Funding: Funding support for this project was provided in part by the Institutional Development Award (IDeA) from the National Institute of General Medical Sciences of the National Institutes of Health, which funds the University of Rhode Island Core Lab (P20GM103430). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e605 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information Frances Kazal More articles by this author Meiwen Ding More articles by this author Dicken Ko More articles by this author Reginald Gohh More articles by this author Nisanne Ghonem More articles by this author Expand All Advertisement PDF DownloadLoading ...

Specific bFGF targeting of KIM-1 in ischemic kidneys protects against renal ischemia-reperfusion injury in rats.

Renal ischemia-reperfusion (I/R) injury is one of the major causes of acute kidney injury. However, there is still no effective treatment for this disease. Basic fibroblast growth factor (bFGF) has been reported to be beneficial for recovery from ischemic diseases. It is vital to increase the local concentration and reduce the diffusion of bFGF in vivo for renal I/R injury therapy. A targeted growth factor delivery system that responds to specific biological signals in the regenerative environment to guide release has been highlighted in tissue repair. In the present study, a specific peptide was fused with bFGF and called bFGF-kidney injury targeting (KIT-bFGF), and this compound specifically targeted kidney injury molecule-1 both in hypoxic renal HK-2 cells in vitro and ischemic kidneys in vivo after intravenous injection. When administered to rat models of renal I/R injury, KIT-bFGF attenuated renal tubule damage and fibrosis, and promoted functional recovery compared to the effects of native bFGF and the control. We also investigated the mechanism by which KIT-bFGF activated the ERK1/2 and Akt signaling pathways to significantly reduce apoptosis and protect against ischemic injury in the kidney. These results demonstrated that targeted delivery of KIT-bFGF could be an effective strategy for the treatment of renal I/R injury.

Renoprotective effect of vinpocetine against ischemia/reperfusion injury: Modulation of NADPH oxidase/Nrf2, IKKβ/NF-κB p65, and cleaved caspase-3 expressions.

Ischemia/reperfusion injury (IRI) during kidney transplantation is a serious clinical problem with a high mortality rate and a lack of therapy. Therefore, there is a need to improve the ability of the kidney to tolerate IRI during transplantation. This study aimed to investigate the possible protective effect of vinpocetine; a derivative of vincamine alkaloid; against renal IRI in rats with the elucidation of the involved mechanisms. Vinpocetine (25 mg/kg; i.p.) was administered for 10 successive days before the induction of ischemia by bilateral clamping of both renal pedicles for 45 min followed by 24 h of reperfusion. Blood and renal tissue samples were then collected for biochemical, molecular, and histopathological investigations. Vinpocetine significantly reduced serum creatinine and blood urea nitrogen levels in rats subjected to IRI. It also reduced mRNA expression of NADPH oxidase and renal content of malondialdehyde, while enhanced Nrf2 protein expression and renal content of reduced glutathione. The suppression of the provoked inflammatory response was evident by the downregulation of IKKβ and NF-κB p65 protein expressions, as well as their downstream inflammatory markers; tumor necrosis factor-α, interleukin-6, and myeloperoxidase. In addition, vinpocetine reduced protein expression of the apoptotic executioner cleaved caspase-3. These nephroprotective effects were confirmed by the improvement in histopathological features. Collectively, the protective effect of vinpocetine against IRI could be attributed to modulation of NADPH oxidase/Nrf2, IKKβ/NF-κB p65, and cleaved caspase-3 expressions. Thus, vinpocetine could improve oxidant/antioxidant balance, suppress triggered inflammatory response, and promote renal cell survival after IRI.

P66Shc signaling does not contribute to tubular damage induced by renal ischemia-reperfusion injury in rat

Renal ischemia-reperfusion (IR) injury is one of the major causes of acute kidney injury and represents a significant risk factor for renal transplantation. The level of renal damage is influenced by the ischemic duration and is caused by excessive amounts of produced reactive oxygen species (ROS). Adaptor protein p66Shc is known to regulate cellular and organ's sensitivity to oxidative stress and to contribute significantly to mitochondrial production of hydrogen peroxide in stress conditions. Studies carried out in cultured renal cells suggest that p66Shc-mediated mitochondrial dysfunction and ROS production are responsible for renal ischemic injury. We used our genetically modified rats, which either lack p66Shc expression, or express p66Shc variant, which constitutively generates increased quantities of hydrogen peroxide, to evaluate potential contribution of p66Shc signaling to renal damage in ischemia reperfusion rat model. Analysis of outer medulla tubule damage revealed the lack of contribution of either p66Shc expression or its constitutive signaling to IR injury in rat model.

Ischemic preconditioning-induced protective effect for promoting angiogenesis in renal ischemia-reperfusion injury by regulating miR-376c-3p/HIF-1α/VEGF axis in male rats

ObjectiveIschemic preconditioning (IPC) is defined as a well-established phenomenon in which brief exposure to sublethal episodes of ischemia and reperfusion induces a tolerance to injurious effects of prolonged ischemia by exploiting intrinsic defence mechanisms. The present study was performed to determine the protective effect of IPC on the rat renal ischemia-reperfusion injury (IRI) via miR-376c-3p/HIF-1α/VEGF axis. MethodsIn vivo, these male Sprague-Dawley rats were treated by IRI and IPC. Meanwhile, these rats from different treatment groups were also injected subcutaneously with 2 nmol agomir-376c-3p and/or 10 nmol recombinant rat HIF-1α. At 72 h after reperfusion, serum samples were respectively collected for renal function. Besides, kidney tissues were harvested to observe renal morphology changes. Subsequently, the expression levels of CD31, HIF-1α and VEGF in the kidney tissues were measured using immunohistochemical staining, quantitative real-time PCR, as well as Western blotting analysis at the indicated time points after reperfusion. In vitro, HK-2 cells were used to detect the cell activity by CCK-8 and transfection of mir-376c-3p mimic in Hypoxia/Reoxygenation (H/R) group. ResultsIn vivo, the pathological changes were significantly relieved in the rats with IPC group, compared to the IRI group. Rats which were treated IPC significantly reduced the levels of blood urea nitrogen (BUN), serum creatinine (Scr) at 24 h after operation, compared to IRI group. After IPC treatment, the expression level of CD31 was obviously decreased, compared to IRI group. A total of differently expressed microRNAs were screened out by microRNA microarray assay in rat renal ischemia tissue, especially showing that miR-376c-3p was selected as the target miRNA. Compared to IRI group, the expression level of miR-376c-3p were obviously higher in IPC-treated group. Double-luciferase reporter assay demonstrated that miR-376c-3p directly targeted HIF-1α. In vitro, IPC significantly increased cell viability of HK-2, and promoted the angiogenesis via up-regulating miR-376c-3p/HIF-1α/VEGF axis. Furthermore, the expression level of HIF-1α was apparently decreased in HK-2 treated with H/R after miR-376c-3p mimic transfection respectively, as well as the increased expression level of VEGF. ConclusionsOur study provided a novel insight for investigating the protective effect of IPC on renal IRI. Consequently, miR-376c-3p played an important role in renal IRI by promoting angiogenesis via targeting HIF-1α/VEGF pathway in male rats.