Bee venom ameliorates gentamicin-induced kidney injury by restoring renal aquaporins and enhancing antioxidant and anti-inflammatory activities in rats

Introduction

Gentamicin (GM) is a frequently used aminoglycoside for managing serious illnesses; nonetheless, renal complications limit its use. Bee venom (BV) is a biological toxin that exhibits anti-inflammatory and antioxidant activities. This study was designed to explore the mitigating effect of BV remediation on GM induced renal injury.

Methods

Twenty male rats were divided into four groups (five rats each), namely, control (saline subcutaneously); BV group (1 mg/kg S/C twice weekly for 1 month); GM group (100 mg/kg i. p. for 1 week); and GM-BV group (the same aforementioned dosages of GM and BV, with GM administered in the last week for 4 weeks).

Results and discussion

BV mitigated the GM-inflicted kidney damage, as evidenced by a substantial improvement in the renal function and oxidative state. In addition, a downregulation in the expression of inflammatory biomarkers (Casp-1, IL-6, TNF-α, and NF-κB/P65/P50) and an upregulation of oxidative stress marker expression (NRF2) were noticed. BV upregulated the expression of aquaporins (AQPs) and renal water channel proteins (AQP1 and AQP2), which are useful for the early detection of renal injury. Additionally, BV exposure exerted a mitigating effect on the apoptotic cascade, as evidenced by the downregulation of cleaved Caspase-3 (Casp-3) and cytochrome c (Cyto c). BV administration also led to an improvement in RBC, WBC, and platelet counts, along with enhanced Hb levels. Interestingly, BV could protect against GM triggered nephrotoxicity.

Effect of the location and severity of partial ureteral obstruction on urinary system stone disease formation

This study aimed to observe the effect of the location and severity of partial ureteral obstruction, based on ureteropelvic and ureterovesical junction strictures, on stone formation. Forty 8-week-old male rats were divided into five groups: control and mild/severe proximal or distal ureteral obstruction groups. A partial ureteral obstruction was created according to the type of obstruction by a surgical procedure. After 5 days of intraperitoneal glyoxylate injection, the urine, blood samples, and kidney tissues of the rats were examined. There were significant differences in urine citrate concentrations, pH values, and oxalate/creatinine, citrate/creatinine, and calcium/creatinine ratios between the groups (all p < 0.05). The mean citrate/creatinine ratio was 21.13 ± 0.44 in the control group, 17.31 ± 3.82 in the distal obstruction group, and 15.48 ± 1.87 in the proximal obstruction group. Regarding the degree of obstruction, urine citrate concentrations, pH values, and citrate/creatinine were lower, and the oxalate/creatinine ratio was higher in severe obstruction than in mild obstruction (p < 0.05). This study represents an initial attempt to evaluate a model of partial ureteral obstruction and urolithiasis. The findings indicate that obstruction alters urinary parameters, such as citrate and pH, indirectly increasing the risk of stone formation. Furthermore, stone formation in an obstructed urinary system appears to be a complex process. However, metabolic evaluation and treatment may help prevent stone formation in patients with ureteral obstruction.

Effects of non-contact electric fields on the kidneys and livers of tumour-bearing rats

Background

A novel modality of cancer treatment based on exposure to non-contact electric fields called Electro-Capacitive Cancer Therapy (ECCT) has been developed. However, the effects of this modality on vital organs during cancer treatment have not been fully investigated. Therefore, this study aimed to investigate the effects of non-contact electric field exposure on kidney and liver structures.

Methods

Female rats were randomly divided into one control group and three treatment groups with six replications each. Animals were treated with 7,12-dimethylbenz[a]anthracene at a dose of 20 mg/kg body weight for mammary tumour induction. Animals were then exposed to electric fields (100 kHz, 50-60 V/m) for 10 hours a day for three weeks. Two kidney samples and two liver samples from different animals in each group were collected for observation of structural damage to the organs. Histopathological cross-sections of the kidneys and livers were made using the paraffin method and Hematoxylin-Eosin staining. Histological scoring used the post-examination masking method with 100 visual fields per group.

Results

There was no significant damages to the tubules, glomeruli, and interstitial of the kidneys, including congestion, after exposure to non-contact electric fields. In addition, healthy rats exposed to this electric field showed significantly lower renal interstitial damage. There was no significant cellular damage, congestion, and haemorrhage in the livers of all groups, except in the healthy rat group that showed significantly higher haemorrhage.

Conclusions

Exposure to non-contact electric fields may cause haemorrhage in the livers of healthy rats. However, in kidney tissue, exposure to this electric field was tolerable, and can even decrease the number of inflammations and haemorrhages in healthy rats.

Toxicokinetic profiling of VRP-034: Evaluating its potential in mitigating polymyxin-B-associated nephrotoxicity

This study assessed the nephrotoxicity and toxicokinetic profile of VRP-034 [a novel formulation of polymyxin B (PMB)] compared with marketed PMB over a 7-day repeat-dose regimen. Three objectives were pursued: evaluating PMB pharmacokinetics in both groups, alongside assessing the impact of VRP-034 on mitigating PMB-associated kidney injury; analysing the reversibility of kidney injury; and validating novel kidney injury biomarkers against traditional markers using histopathological scoring. Sixty-eight Sprague-Dawley rats were divided into three groups: 30 in each of the marketed PMB and VRP-034 groups, and eight in the control group. Rats received drugs at 6 mg/kg subcutaneously every 8 h (human equivalent dose ∼3 mg/kg/day). Toxicokinetic evaluations were conducted on selected animals on days 1, 2, 4, and 7 (after 3rd, 6th, 12th and 21st dose), while the remaining animals were observed for an additional 7 days without treatment. Samples were collected up to 12 h post-administration, followed by necropsy and histopathological examination. Plasma PMB concentrations were quantified; and kidney injury biomarkers, oxidative stress and anti-inflammatory markers were evaluated. Receiver operating characteristic curve analysis was performed to validate kidney injury biomarkers against histopathological grading. Similar plasma PMB concentrations and pharmacokinetic parameters were found in the two treatment groups. However, the VRP-034 group exhibited significantly lower nephrotoxicity, with reduced levels of kidney injury biomarkers, and diminished oxidative stress and inflammation levels compared with the marketed PMB group. Histopathological examination confirmed reduced renal damage in the VRP-034 group. Novel kidney injury biomarkers demonstrated superior sensitivity, specificity and early detection capability over traditional markers. In conclusion, VRP-034 demonstrated reduced nephrotoxicity compared with marketed PMB, suggesting its potential as a safer alternative.

Evaluation of Xanthine Oxidase Inhibitors Febuxostat and Allopurinol on Kidney Dysfunction and Histological Damage in Two-Kidney, One-Clip (2K1C) Rats

In chronic kidney disease (CKD), hyperuricemia is a common phenomenon, presumably due to reduced renal clearance of uric acid. This study investigated the effect of xanthine oxidase (XO) inhibitors allopurinol and febuxostat to prevent oxidative stress in the kidney of two-kidney, one-clip (2K1C) rats. In this investigation, 2K1C rats were used as an experimental animal model for kidney dysfunction. 2K1C rats were provided with food and drinking water and received febuxostat at a dose of 10 mg/kg or allopurinol at 100 mg/kg, respectively. After the treatment completion, all rats were sacrificed, and tissue samples were collected. 2K1C rats exhibited increased plasma creatinine, uric acid level, and glomerular injury assessed based on microscopic findings. Both allopurinol and febuxostat significantly normalized creatinine and uric acid levels. Furthermore, 2K1C rats showed increased lipid peroxidation (LPO), nitric oxide (NO), and advanced oxidation protein products (AOPP) alongside decreased superoxide dismutase (SOD) and catalase activity. Again, both drug treatments ameliorated these elevated oxidative stress parameters in 2K1C rats. The antioxidant genes such as Nrf-2, HO-1, and SOD were also restored in the kidneys of 2K1C rats by allopurinol and febuxostat treatment. 2K1C rats also showed increased IL-1β, IL-6, TNF-α, and NF-кB mRNA expression in the kidneys which were normalized by allopurinol and febuxostat treatment. Thus, the data suggest that XO inhibition protects kidney function potentially by restoring antioxidant enzyme function and suppressing inflammation.

Oxygenation by Intravascular Photosynthesis Reduces Kidney Damage During ex Vivo Preservation

Several clinical issues are associated with reduced oxygen delivery to tissues due to impaired vascular perfusion; moreover, organs procured for transplantation are subjected to severe hypoxia during preservation. Consequently, alternative tissue oxygenation is an active field in biomedical research where several innovative approaches have been recently proposed. Among these, intravascular photosynthesis represents a promising approach as it relies on the intrinsic capacity of certain microorganisms to produce oxygen upon illumination. In this context, this work aims at the development of photosynthetic perfusable solutions that could be applied to preserve organs for transplantation purposes. Our findings demonstrate that a biocompatible physiological solution containing the photosynthetic microalgae Chlamydomonas reinhardtii can fulfill the metabolic oxygen demand of rat kidney slices in vitro. Furthermore, intravascular administration of this solution does not induce tissue damage in the rat kidneys. Moreover, kidney slices obtained from these algae-perfused organs exhibited significantly improved preservation after 24 h of incubation in hypoxia while exposed to light, resulting in reduced tissue damage and enhanced metabolic status. Overall, the results presented here contribute to the development of alternative strategies for tissue oxygenation, supporting the use of perfusable photosynthetic solutions for organ preservation in transplantation.

Repurposing Dapagliflozin for Mitigation of the Kidney Injury Triggered by Cadmium in Rats: Role of Autophagy, Apoptosis, and the SIRT1/Nrf2/HO-1 Pathway

Background/Objectives: The antioxidant/antiapoptotic features of dapagliflozin (DPG) have mediated its beneficial actions against several experimental models. However, no studies have been conducted to determine whether DPG mitigates the renal injury triggered by cadmium (Cd). Herein, DPG was studied for its potential to attenuate kidney damage in Cd-intoxicated rats, as well as to unravel the mechanisms involving oxidative events, autophagy, and apoptosis. Methods: Histopathological analysis, immunohistochemical staining, and ELISA were conducted on kidney tissue samples. Results: Cd administration (5 mg/kg/day; p.o.) prompted significant renal damage, as evidenced by histopathological changes, elevated kidney injury molecule-1 (KIM-1) expression, and increased serum creatinine and urea. Interestingly, DPG (1 mg/kg/day; p.o.) significantly mitigated these harmful effects without affecting renal Cd metal accumulation. Mechanistically, DPG curbed Cd-induced renal pro-oxidant response and stimulated the antioxidant sirtuin 1 (SIRT1)/nuclear factor (erythroid-derived 2)-like 2 (Nrf2)/heme oxygenase 1 (HO-1) axis. Moreover, DPG restored autophagy by decreasing sequestosome-1/protein 62 (SQSTM-1/p62) accumulation and stimulating the AMP-activated protein kinase (AMPK)/mechanistic target of rapamycin (mTOR) pathway. In tandem, DPG suppressed Cd-induced apoptosis by lowering renal Bcl-2 associated-x protein (Bax) and cytochrome C (Cyt C) levels and caspase 3 activity. Conclusions: These findings indicate that DPG attenuates Cd-induced nephrotoxicity by enhancing the SIRT1/Nrf2/HO-1 antioxidant pathway, promoting AMPK/mTOR-directed autophagy, and inhibiting apoptotic cell death.

Silibinin-loaded Nanostructured Lipid Carriers (NLCs) Ameliorated Lead-induced Acute Nephrotoxicity in Male Rats

As a toxic heavy metal, lead (Pb) is well known for impairment of renal function due to oxidative injuries. In contrast, the antioxidant activity of silibinin has been approved. Given the role of silibinin antioxidant activity, the present study investigated the effectiveness of silibinin-loaded nanostructured lipid carriers (Sili-NLCs) against Pb-induced acute nephrotoxicity in rats. The emulsification-solvent evaporation method was applied to prepare Sili-NLCs. Sixty male Wistar rats were divided into ten separate groups. Pb (20 mg/kg/day, i.p.) was applied to induce nephrotoxicity and in the treatment groups animals received the same concentration of silibinin and Sili-NLCs (25, 50, and 100 mg/kg/day, p.o.) for five days. After sacrificing rats, kidney tissue samples were collected to assess the oxidative stress parameters, including lipid peroxidation (LPO), nitric oxide (NO), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activity. Also, histopathological examination using Hematoxylin-Eosin (H&E) was studied. Not only did Pb injection significantly increase the renal levels of LPO and NO, but also decreased the levels of antioxidant enzyme activity. On the other hand, Sili-NLCs were more effective than silibinin in decreasing renal oxidative damage by increasing the antioxidant defense system. Moreover, the histopathological examination correlated well with biochemical findings. Our data suggested that Sili-NLCs are potentially superior to pure silibinin for attenuating Pb-induced acute nephrotoxicity.

TARGETED TEMPERATURE MANAGEMENT AT 36°C IMPROVES SURVIVAL AND PROTECTS TISSUES BY MITIGATING THE DELETERIOUS INFLAMMATORY RESPONSE FOLLOWING HEMORRHAGIC SHOCK

ABSTRACT

Hemorrhagic shock (HS) is a life-threatening condition with high mortality rates despite current treatments. This study investigated whether targeted temperature management (TTM) could improve outcomes by modulating inflammation and protecting organs following HS. Using a rat model of HS, TTM was applied at 33°C and 36°C after fluid resuscitation. Surprisingly, TTM at 33°C increased mortality, while TTM at 36°C significantly improved survival rates. It also reduced histological damage in lung and kidney tissues, lowered serum lactate levels, and protected against apoptosis and excessive reactive oxygen species production. TTM at 36°C inhibited the release of high mobility group box 1 protein (HMGB1), a key mediator of inflammation, and decreased proinflammatory cytokine levels in the kidneys and lungs. Moreover, it influenced macrophage behavior, suppressing the harmful M1 phenotype while promoting the beneficial M2 polarization. Cytokine array analysis confirmed reduced levels of proinflammatory cytokines with TTM at 36°C. These results collectively highlight the potential of TTM at 36°C as a therapeutic approach to improve outcomes in HS. By addressing multiple aspects of injury and inflammation, including modulation of macrophage responses and cytokine profiles, TTM at 36°C offers promising implications for critical care management after HS, potentially reducing mortality and improving patient recovery.

Dear Laparoscopic Surgeons: Caution with the Use of Glutaraldehyde!!!

Background

The occupational hazards of glutaraldehyde are well known; the possibility of harm to the patients has been highlighted in the form of isolated reports only.

Objective

To synthesize evidence for contact mucosal injury or injury due to intraperitoneal instillation of glutaraldehyde following its use during laparoendoscopy.

Materials and Methods

The current review is Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) compliant. PubMed, PubMed Central, and Google Scholar were interrogated for animal and human studies upon the harmful effects of glutaraldehyde during laparoscopy and proctosigmoido-colonoscopy.

Results

Thirty-five studies substratified into animal experiments (n = 2), glutaraldehyde-induced colitis (G-iC) postendoscopy (n = 30), and laparoscopy (n = 3) were included. Rats suffered mucosal injury following colonic injection of glutaraldehyde which was time- and concentration-dependent quantum and developed bloody diarrhoea. Omental and renal injury was observed due to glutaraldehyde instillation during simulation of intra-peritoneal insufflation in rats; the serum leucocytes, CRP and creatinine were also elevated. G-iC following colonoscopy was related to contact mucosal injury due to failure (human or machinery) to rinse the chemical off the instrument surface or as a case of mistaken identity (glutaraldehyde was mistaken for saline or another reagent). The incubation period was <24 h in 90% of patients; clinical presentation was related to the initiation of intense inflammation. Intraperitoneal instillation during laparoscopy also leads to intense inflammation. One patient was asymptomatic, the second required laparotomy and peritoneal irrigation for 48 h, while the third case underwent multiple laparotomies for enteric cutaneous and enteroenteric fistulae, adhesions, and multiple intra-abdominal abscesses. Hydronephrosis consequent to retroperitoneal fibrosis has been reported.

Conclusions

The use of glutaraldehyde in the patient care facilities should be discontinued; when unavoidable, the standard processes of disinfection and rinsing must be stringently followed.

Metagenomics and metaproteomics alterations are associated with kidney disease in opisthorchiasis hamsters fed a high-fat and high-fructose diet

BACKGROUND

Opisthorchis viverrini (O. viverrini, Ov) infection and consumption of high-fat and high-fructose (HFF) diet exacerbate liver and kidney disease. Here, we investigated the effects of a combination of O. viverrini infection and HFF diet on kidney pathology via changes in the gut microbiome and host proteome in hamsters.

METHODOLOGY/PRINCIPAL FINDINGS

Twenty animals were divided into four groups; 1) fed a normal diet not infected with O. viverrini (normal group), 2) fed an HFF diet and not infected with O. viverrini (HFF), 3) fed a normal diet and infected with O. viverrini (Ov), and 4) fed an HFF diet and infected with O. viverrini (HFFOv). DNA was extracted from fecal samples and the V3-V4 region of the bacterial 16S rRNA gene sequenced on an Illumina MiSeq sequencing platform. In addition, LC/MS-MS analysis was done. Histopathological studies and biochemical assays were also conducted. The results indicated that the HFFOv group exhibited the most severe kidney injury, manifested as elevated KIM-1 expression and accumulation of fibrosis in kidney tissue. The microbiome of the HFFOv group was more diverse than in the HFF group: there were increased numbers of Ruminococcaceae, Lachnospiraceae, Desulfovibrionaceae and Akkermansiaceae, but fewer Eggerthellaceae. In total, 243 host proteins were identified across all groups. Analysis using STITCH predicted that host proteome changes may lead to leaking of the gut, allowing molecules such as soluble CD14 and p-cresol to pass through to promote kidney disease. In addition, differential expression of TGF-beta-activated kinase 1 and MAP3K7-binding protein 2 (Tab2, involving renal inflammation and injury) are predicted to be associated with kidney disease.

CONCLUSIONS/SIGNIFICANCE

The combination of HFF diet and O. viverrini infection may promote kidney injury through alterations in the gut microbiome and host proteome. This knowledge may suggest an effective strategy to prevent kidney disease beyond the early stages.

Renoprotective effect of diacetylrhein on diclofenac-induced acute kidney injury in rats via modulating Nrf2/NF-κB/NLRP3/GSDMD signaling pathways

Diclofenac (DF)-induced acute kidney injury (AKI) is characterized by glomerular dysfunction and acute tubular necrosis. Due to limited treatment approaches, effective and safe drug therapy to protect against such AKI is still needed. Diacetylrhein (DAR), an anthraquinone derivative, has different antioxidant and anti-inflammatory properties. Therefore, the aim of the current study was to investigate the renoprotective effect of DAR on DF-induced AKI while elucidating the potential underlying mechanism. Our results showed that DAR (50 and 100 mg/kg) markedly abrogated DF-induced kidney dysfunction decreasing SCr, BUN, serum NGAL, and serum KIM1 levels. Moreover, DAR treatment remarkably maintained renal redox balance and reduced the levels of pro-inflammatory biomarkers in the kidney. Mechanistically, DAR boosted Nrf2/HO-1 antioxidant and anti-inflammatory response in the kidney while suppressing renal TLR4/NF-κB and NLRP3/caspase-1 inflammatory signaling pathways. In addition, DAR markedly inhibited renal pyroptosis via targeting of GSDMD activation. Collectively, this study confirmed that the interplay between Nrf2/HO-1 and TLR4/NF-κB/NLRP3/Caspase-1 signaling pathways and pyroptotic cell death mediates DF-induced AKI and reported that DAR has a dose-dependent renoprotective effect on DF-induced AKI in rats. This effect is due to powerful antioxidant, anti-inflammatory, and anti-pyroptotic activities that could provide a promising treatment approach to protect against DF-induced AKI.

Dextrin conjugation to colistin inhibits its toxicity, cellular uptake and acute kidney injury in vivo

The acute kidney injury (AKI) and dose-limiting nephrotoxicity, which occurs in 20-60% of patients following systemic administration of colistin, represents a challenge in the effective treatment of multi-drug resistant Gram-negative infections. To reduce clinical toxicity of colistin and improve targeting to infected/inflamed tissues, we previously developed dextrin-colistin conjugates, whereby colistin is designed to be released by amylase-triggered degradation of dextrin in infected and inflamed tissues, after passive targeting by the enhanced permeability and retention effect. Whilst it was evident in vitro that polymer conjugation can reduce toxicity and prolong plasma half-life, without significant reduction in antimicrobial activity of colistin, it was unclear how dextrin conjugation would alter cellular uptake and localisation of colistin in renal tubular cells in vivo. We discovered that dextrin conjugation effectively reduced colistin's toxicity towards human kidney proximal tubular epithelial cells (HK-2) in vitro, which was mirrored by significantly less cellular uptake of Oregon Green (OG)-labelled dextrin-colistin conjugate, when compared to colistin. Using live-cell confocal imaging, we revealed localisation of both, free and dextrin-bound colistin in endolysosome compartments of HK-2 and NRK-52E cells. Using a murine AKI model, we demonstrated dextrin-colistin conjugation dramatically diminishes both proximal tubular injury and renal accumulation of colistin. These findings reveal new insight into the mechanism by which dextrin conjugation can overcome colistin's renal toxicity and show the potential of polymer conjugation to improve the side effect profile of nephrotoxic drugs.

A short treatment with resveratrol after a renal ischaemia-reperfusion injury prevents maladaptive repair and long-term chronic kidney disease in rats

Acute kidney injury (AKI) often triggers physiological processes aimed at restoring renal function and architecture. However, this response can become maladaptive, leading to nephron loss and fibrosis. Although the therapeutic effects of resveratrol (RSV) are well established, its impact after AKI and for subsequent chronic kidney disease (CKD) remains unclear. This study assessed whether transient administration of RSV following ischaemia-reperfusion injury (IRI) could prevent the progression to CKD. Forty-one male Wistar rats were assigned randomly to sham surgery, bilateral renal ischaemia for 30 min (IR) or IR+RSV. The RSV treatment commenced 24 h after IRI and continued for 10 days. The rats were studied for either 10 days or 5 months, after which kidney function and structure were evaluated. Mitochondrial homeostasis, oxidant defence and renal inflammation state were also evaluated. Despite having the same severity of AKI, rats receiving RSV for 10 days after IRI exhibited significant improvement in kidney histological injury and reduced inflammation, although renal haemodynamic recovery was less pronounced. Resveratrol effectively prevented the elevation of tubular injury-related molecules and profibrotic signalling with reduced myofibroblast proliferation. Furthermore, RSV substantially improved the antioxidant response and mitochondrial homeostasis. After 5 months, RSV prevented the transition to CKD, as evidenced by the prevention of progressive proteinuria, renal dysfunction and tubulointerstitial fibrosis. This study demonstrates that a brief treatment with RSV following IRI is enough to prevent maladaptive repair and the development of CKD. Our findings highlight the importance of the early days of reperfusion, indicating that maladaptive responses can be reduced effectively following severe AKI. KEY POINTS: Physiological processes activated after acute kidney injury (AKI) can lead to maladaptive responses, causing nephron loss and fibrosis. Prophylactic renoprotection with resveratrol (RSV) has been described in experimental AKI, but its impact after AKI and for subsequent chronic kidney disease (CKD) remains unclear. In this study, we found that histological tubular injury persists 10 days after ischaemia-reperfusion injury and contributes to a failed repair phenotype in proximal tubular cells. Short-term RSV intervention influenced the post-ischaemic repair response and accelerated tubular recovery by reducing oxidative stress and mitochondrial damage. Furthermore, RSV targeted inflammation and profibrotic signalling during the maladaptive response, normalizing both processes. Resveratrol effectively prevented AKI-to-CKD transition even 5 months after the intervention. The study serves as a proof of concept, proposing RSV as a valuable candidate for further translational clinical studies to mitigate AKI-to-CKD transition.

Efficacy of metamizole to prevent kidney injury after renal-ischaemic reperfusion injury in Wistar rats

Background

Renal ischaemia-reperfusion injury (RIRI) is a common kidney procedure complication due to temporary blood flow interruption, leading to kidney injuries. This study aimed to analyze the effect of metamizole on the levels of interleukin-18 (IL-18), neutrophil-gelatinase-associated lipocalin (NGAL), myeloperoxidase (MPO), and histopathological changes in rats with RIRI.

Materials and methods

Animal pre-clinical design study was used. Thirty-two male Wistar rats (Rattus norvegicus) were divided into four groups: negative control, positive control, M100, and M200. Blood samples were collected by intracardiac puncture, followed by bilateral nephrectomy and analyzed histopathologically.

Results

Significant difference in IL-18 levels between positive control vs negative control (114.1 + 12.07 vs. 94.0 + 11.4; P = 0.019) and positive control vs M100 (114.1 + 12.07 vs. 86.9 + 8.34; P = 0.007). There was no difference in NGAL. M100 group had the lowest serum MPO levels (14.78+2.01), there was a significant difference in MPO levels in all pairwise analyses. There was a difference in cumulative EGTI scores among the study groups [positive 10.5 (8-11) vs. negative 9 (7-10) vs. M100 9 (7-10) vs. M200 9 (7-11); P = 0.021].

Conclusion

Metamizole 100 mg/kgBW can reduce IL-18 and MPO levels in RIRI, giving more optimal results without affecting NGAL levels. Metamizole administration can reduce cumulative EGTI scores in RIRI, both at doses of 100 mg/kgBW and 200 mg/kgBW. This study shows that Metamizole can be used to prevent kidney injury caused by RIRI. IL-18 and MPO can be biomarkers in predicting kidney injury in RIRI.

Transient inhibition of sodium-glucose cotransporter 2 after ischemia/reperfusion injury ameliorates chronic kidney disease

Sodium-glucose cotransporter 2 (SGLT2) inhibitor, dapagliflozin (Dapa), exhibited nephroprotective effects in patients with chronic kidney disease (CKD). We assessed the efficacy of short-term Dapa administration following acute kidney injury (AKI) in preventing CKD. Male Wistar rats were randomly assigned to Sham surgery, bilateral ischemia for 30 minutes (abbreviated as IR), and IR + Dapa groups. Daily treatment with Dapa was initiated just 24 hours after IR and maintained for only 10 days. Initially, rats were euthanized at this point to study early renal repair. After severe AKI, Dapa promptly restored creatinine clearance (CrCl) and significantly reduced renal vascular resistance compared with the IR group. Furthermore, Dapa effectively reversed the mitochondrial abnormalities, including increased fission, altered mitophagy, metabolic dysfunction, and proapoptotic signaling. To study this earlier, another set of rats was studied just 5 days after AKI. Despite persistent renal dysfunction, our data reveal a degree of mitochondrial protection. Remarkably, a 10-day treatment with Dapa demonstrated effectiveness in preventing CKD transition in an independent cohort monitored for 5 months after AKI. This was evidenced by improvements in proteinuria, CrCl, glomerulosclerosis, and fibrosis. Our findings underscore the potential of Dapa in preventing maladaptive repair following AKI, emphasizing the crucial role of early intervention in mitigating AKI long-term consequences.

Protective effects of l-carnitine on isoprenaline -induced heart and kidney dysfunctions: Modulation of inflammation and oxidative stress-related gene expression in rats

The aim of this study was to evaluate the effect of l-carnitine (L-CAR) treatment on isoprenaline (ISO) administered kidney and heart impairment in male Long Evans rats. Four groups of rats were engaged in this study such as control, ISO, control + L-CAR, and ISO + L-CAR, where n = 6 in each group. The rats were also provided with chow food and water ad libitum. At the end of the study, all rats were sacrificed, and blood and tissue samples were collected for bio-chemical analysis. Oxidative stress parameters and antioxidant enzyme activities were determined in plasma and tissues. Antioxidant and inflammatory genes expression were analyzed in the kidney cortex, and histopathological studies of kidney tissues were performed. This study showed that creatinine and uric acid in plasma were significantly increased in ISO-administered rats. l-carnitine treatment lowered the uric acid and creatinine level. ISO-administered rats showed increased lipid peroxidation and declined levels of antioxidant enzymes activities in kidneys and heart. l-carnitine treatment restored antioxidant enzymes activities and protect against oxidative stress in kidney and heart. This effect is correlated with the restoration of Nrf-2-HO-1 genes expression followed by increased SOD and catalase genes expression in the kidney. l-carnitine treatment also prevented the TNF-α, IL-6, and NF-кB expression in kidneys of ISO administered rats. Histopathology staining showed that l-carnitine treatment prevented kidney damage and collagen deposition in ISO administered rats. The result of this study exhibited that l-carnitine treatment reduced oxidative stress and increased antioxidant enzyme activities by enhancing antioxidant genes expression in ISO administered rats.

Evaluating the Effects of Kidney Preservation at 10 °C with Hemopure and Sodium Thiosulfate in a Rat Model of Syngeneic Orthotopic Kidney Transplantation

Kidney transplantation is preferred for end-stage renal disease. The current gold standard for kidney preservation is static cold storage (SCS) at 4 °C. However, SCS contributes to renal graft damage through ischemia-reperfusion injury (IRI). We previously reported renal graft protection after SCS with a hydrogen sulfide donor, sodium thiosulfate (STS), at 4 °C. Therefore, this study aims to investigate whether SCS at 10 °C with STS and Hemopure (blood substitute), will provide similar protection. Using in vitro model of IRI, we subjected rat renal proximal tubular epithelial cells to hypoxia-reoxygenation for 24 h at 10 °C with or without STS and measured cell viability. In vivo, we preserved 36 donor kidneys of Lewis rats for 24 h in a preservation solution at 10 °C supplemented with STS, Hemopure, or both followed by transplantation. Tissue damage and recipient graft function parameters, including serum creatinine, blood urea nitrogen, urine osmolality, and glomerular filtration rate (GFR), were evaluated. STS-treated proximal tubular epithelial cells exhibited enhanced viability at 10 °C compared with untreated control cells (p < 0.05). Also, STS and Hemopure improved renal graft function compared with control grafts (p < 0.05) in the early time period after the transplant, but long-term function did not reach significance. Overall, renal graft preservation at 10 °C with STS and Hemopure supplementation has the potential to enhance graft function and reduce kidney damage, suggesting a novel approach to reducing IRI and post-transplant complications.

Impact of folic acid supplementation on ischemia‒reperfusion-induced kidney injury in rats: folic acid prophylactic role revisited

Folic acid (FA), with its anti-inflammatory and antioxidant properties, may offer protection against ischemia-reperfusion (IR) injury. This study investigated whether FA safeguards rat kidneys from IR by targeting high mobility group box-1 (HMGB1), a key inflammatory mediator. Fifty adult male Wistar rats were randomly allocated into four groups: control, IR, IR + FA pretreatment, and FA alone. Compared to controls, IR significantly impaired renal function and elevated levels of malondialdehyde, HMGB1, NF-κB, and caspase 3. FA pretreatment effectively reversed these detrimental changes, protecting renal function and minimizing tissue damage. The FA-alone group showed no significant differences compared to the control group, indicating no adverse effects of FA treatment. Mechanistically, FA inhibited HMGB1 expression and its downstream activation of NF-κB and caspase 3, thereby quelling inflammation and cell death. FA shields rat kidneys from IR-induced injury by suppressing HMGB1-mediated inflammation and apoptosis, suggesting a potential therapeutic avenue for IR-associated kidney damage.

Naringin Affects Caspase-3, IL-1β, and HIF-1α Levels in Experimental Kidney Ischemia-Reperfusion in Rats

BACKGROUND

Microvascular dysfunction develops in tissues after Ischemia-Reperfusion (IR). The current study aimed to determine the effect of naringin supplementation on kidney caspase-3, IL-1β, and HIF-1α levels and kidney histology in rats undergoing unilateral nephrectomy and kidney-ischemia reperfusion.

METHODS

The study was conducted on 8-12 weeks old 40 Wistar-type male rats. Experimental renal ischemia- reperfusion and unilateral nephrectomy were performed under general anesthesia in rats. Experimental groups were formed as follows: 1-Control group, 2-Sham control + Vehicle group, 3- Renal ischemia-reperfusion (Renal I+R) + Vehicle group, 4-Renal I+R + Naringin (50 mg/kg/day) group (3 days application) group, 5-Renal I+R + Naringin (100 mg/kg/day) group (3 days supplementation). Nephrectomy in the left kidneys and the ischemia for 45 minutes and reperfusion in the right kidneys followed by 72 hours of reperfusion. Naringin was administered intraperitoneally at the beginning of the reperfusion, 24 hours and 48 hours later. At the end of the experiments, blood was first taken from the heart in animals under general anesthesia. Then, the animals were killed by cervical dislocation, and kidney tissue samples were taken. Tissues were evaluated for caspase-3, IL-1β, and HIF-1α as well as histologically.

RESULTS

As a result of ischemia in kidney tissues, HIF-1α decreased, while caspase-3 and IL-1β increased. IR also caused damage to the kidney tissue. However, naringin supplementation corrected the deterioration to a certain extent.

CONCLUSION

The results of the study showed that naringin may have protective effects on kidney damage due to anti-inflammatory and antiapoptosis mechanisms caused by unilateral nephrectomy and IR in rats.

Amlodipine alleviates renal ischemia/reperfusion injury in rats through Nrf2/Sestrin2/PGC-1α/TFAM Pathway

BACKGROUND

Previously, observational studies showed that amlodipine can mitigate calcineurin inhibitor- and contrast-induced acute kidney injury (AKI). Herein, we aimed to measure the effect of amlodipine on renal ischemia/reperfusion (I/R) injury and find the underlying mechanisms.

MATERIALS AND METHODS

Bilateral renal I/R was induced by clamping the hilum of both kidneys for 30 min. The first dose of amlodipine 10 mg/kg was gavaged before anesthesia. The second dose of amlodipine was administered 24 h after the first dose. Forty-eight hours after I/R, rats were anesthetized, and their blood and tissue specimens were collected.

RESULTS

Amlodipine significantly decreased the elevated serum levels of creatinine and blood urea nitrogen (BUN) and mitigated tissue damage in hematoxylin & eosin (H&E) staining. Amlodipine strongly reduced the tissue levels of malondialdehyde (MDA), interleukin 1β (IL1β), and tumor necrosis factor α (TNF-α). Amlodipine enhanced antioxidant defense by upregulating nuclear factor erythroid 2-related factor 2 (Nrf2) and Sestrin2. Furthermore, amlodipine significantly improved mitochondrial biogenesis by promoting Sestrin2/peroxisome proliferator-activated receptor-gamma coactivator (PGC-1α)/mitochondrial transcription factor A (TFAM) pathway. It also enhanced autophagy and attenuated apoptosis, evidenced by increased LC3-II/LC3-I and bcl2/bax ratios after renal I/R.

CONCLUSION

These findings suggest that amlodipine protects against renal I/R through Nrf2/Sestrin2/PGC-1α/TFAM Pathway.

Dietary docosahexaenoic acid plays an opposed role in ferroptotic and non-ferroptotic acute kidney injury

Ferroptosis due to polyunsaturated fatty acid (PUFA) peroxidation has been implicated in the pathogenesis of acute kidney injury (AKI), suggesting the risk of dietary intake of PUFA for people susceptible to AKI. Clinically, however, in addition to ferroptosis, other mechanisms also contribute to different types of AKI such as inflammation associated necroptosis and pyroptosis. Therefore, the role of PUFA, especially ω3 PUFA which is a common food supplement, in various AKIs deserves further evaluation. In this study, rhabdomyolysis- and folic acid-induced AKI (Rha-AKI and FA-AKI) were established in mice fed with different fatty acids Histology of kidney, blood urea nitrogen and creatinine, lipid peroxidation, and inflammatory factors were examined. Results showed that these two types of AKIs had diametrically different pathogenesis indicated by that ferrostatin-1 (Fer-1), a lipid antioxidant, can attenuate FA-AKI rather than Rha-AKI. Further, dietary DHA (provided by fish oil) reduced tubular injury and renal lesion by inhibiting peroxidation and inflammation in mice with Rha-AKI while increasing cell death, tissue damage, peroxidation and inflammation in mice with FA-AKI. In human renal tubular epithelial cell line HK-2, MTT assay and DHE staining showed that both myoglobin and ferroptosis inducers can cause cell death and oxidative stress. Ferroptosis inducer-induced cell death was promoted by DHA, while such result was not observed in myoglobin-induced cell death when adding DHA. This study illustrates that the mechanisms of AKI might be either ferroptosis dependent or -independent and the deterioration effect of dietary DHA depends on whether ferroptosis is involved.

Crataeva nurvala Bark (Capparidaceae) Extract Modulates Oxidative Stress-Related Gene Expression, Restores Antioxidant Enzymes, and Prevents Oxidative Stress in the Kidney and Heart of 2K1C Rats

Objective

Crataeva nurvala is a medicinal plant, which contains a wide range of polyphenolic and bioactive compounds. The aim of the study was to evaluate the renal-protective activity of Crataeva nurvala in two-kidney, one-clip (2K1C) rats.

Methods

In this study, the ethanol extract of Crataeva nurvala bark at a dose of 100 mg/kg was orally used to treat 2K1C rats for four weeks. At the end of the experiment, all rats were sacrificed and tissue samples were collected for further biochemical and histological assessments.

Results

This investigation showed that Crataeva nurvala treatment prevented the kidney dysfunction in 2K1C rats. Uric acid and creatinine concentration and CK-MB activities increased in 2K1C rats which were normalized by Crataeva nurvala. 2K1C rats also showed increased oxidative stress, depicted by the elevated level of MDA, NO, and APOP in plasma and tissues. Oxidative stress parameters declined in 2K1C rats by the treatment of Crataeva nurvala. These results could be attributed to the restoration of antioxidant enzyme activities such as catalase and SOD. Crataeva nurvala extracts also upregulated antioxidant gene expression in the kidneys of 2K1C rats. Moreover, several anti-inflammatory genes were suppressed by Crataeva nurvala treatment in 2K1C rats. Furthermore, fibrosis and collagen deposition in the kidneys were also lowered by the treatment of the Crataeva nurvala extract.

Conclusion

The experimental data suggest that the Crataeva nurvala extract protected renal damage and oxidative stress, probably by restoring antioxidant enzymes activities in 2K1C rats.

The Influence of Ultra-Low Tidal Volume Ventilation during Cardiopulmonary Resuscitation on Renal and Hepatic End-Organ Damage in a Porcine Model

The optimal ventilation strategy during cardiopulmonary resuscitation (CPR) has eluded scientists for years. This porcine study aims to validate the hypothesis that ultra-low tidal volume ventilation (tidal volume 2–3 mL kg−1; ULTVV) minimizes renal and hepatic end-organ damage when compared to standard intermittent positive pressure ventilation (tidal volume 8–10 mL kg−1; IPPV) during CPR. After induced ventricular fibrillation, the animals were ventilated using an established CPR protocol. Upon return of spontaneous circulation (ROSC), the follow-up was 20 h. After sacrifice, kidney and liver samples were harvested and analyzed histopathologically using an Endothelial, Glomerular, Tubular, and Interstitial (EGTI) scoring system for the kidney and a newly developed scoring system for the liver. Of 69 animals, 5 in the IPPV group and 6 in the ULTVV group achieved sustained ROSC and were enlisted, while 4 served as the sham group. Creatinine clearance was significantly lower in the IPPV-group than in the sham group (p < 0.001). The total EGTI score was significantly higher for ULTVV than for the sham group (p = 0.038). Aminotransferase levels and liver score showed no significant difference between the intervention groups. ULTVV may be advantageous when compared to standard ventilation during CPR in the short-term ROSC follow-up period.

Hesperidin protects against aluminum-induced renal injury in rats via modulating MMP-9 and apoptosis: biochemical, histological, and ultrastructural study

Aluminum, one of the most abundant metallic elements, is known to be toxic to multiple organs including the kidneys. This study aimed to investigate the pleiotropic nephroprotective effects of Hesperidin in aluminum chloride (ALCL3)-induced renal injury, highlighting the potential molecular mechanisms underlying. Twenty-four male albino rats were divided into four groups: control, Hesperidin (80 mg/kg BW, orally), ALCL3 (10 mg/kg BW, IP), and ALCL3 + Hesperidin groups. By the end of the study, blood samples were collected, and tissue samples were harvested at sacrifice. ALCL3 rats showed dramatically declined renal function, enhanced intrarenal oxidative stress, inflammation, apoptosis, and extravagant renal histopathological damage with interstitial fibrosis as shown by a higher Endothelial, Glomerular, Tubular, and Interstitial (EGTI) score. Hesperidin significantly reversed all the aforementioned detrimental effects in ALCL3-treated rats. The study verified the nephroprotective effects of Hesperidin on ALCL3-induced renal damage and confirmed the critical role of extracellular matrix (ECM) remodeling and apoptosis inhibition.

Co-treatment with grape seed extract and mesenchymal stem cells in vivo regenerated beta cells of islets of Langerhans in pancreas of type I-induced diabetic rats

BACKGROUND

Nowadays, diabetes mellitus is known as a silent killer because individual is not aware that he has the disease till the development of its complications. Many researchers have studied the use of stem cells in treatment of both types of diabetes. Mesenchymal stem cells (MSCs) hold a lot of potential for regenerative therapy. MSCs migrate and home at the damaged site, where they can aid in the repair of damaged tissues and restoring their function. Oxidative stress and inflammation represent a huge obstacle during MSCs transplantation. Therefore, the present study aimed to evaluate the role of grape seed extract (GSE) administration during MSCs transplantation in streptozotocin (STZ)-induced type I diabetes. Furthermore, testing some of GSE components [procyanidins(P)-B1 and P-C1] in conjunction with MSCs, in vivo, was performed to determine if one of them was more effective in relieving the measured attributes of diabetes more than the whole GSE.

METHODS

Firstly, GSE was prepared from the seeds of Muscat of Alexandria grapes and characterized to identify its phytochemical components. Experimental design was composed of control group I, untreated diabetic group II, GSE (300 mg/kg)-treated diabetic group III, MSCs (2 × 106 cells/rat)-treated diabetic group IV and GSE (300 mg/kg)/MSCs (2 × 106 cells/rat)-treated diabetic group V. Type I diabetes was induced in rats by intravenous injection with 65 mg/kg of STZ. Treatment started when fasting blood glucose (FBG) level was more than 200 mg/dl; GSE oral administration started in the same day after MSCs intravenous injection and continued daily for 30 consecutive days.

RESULTS

The results showed that GSE/MSCs therapy in type I-induced diabetic rats has dramatically managed homeostasis of glucose and insulin secretion; together with, improvement in levels of inflammatory markers and oxidative stress.

CONCLUSION

Co-treatment with GSE and MSCs in vivo regenerates beta cells in type I-induced diabetic rats.

Diagnosis of Ischemic Renal Failure Using Surface-Enhanced Raman Spectroscopy and a Machine Learning Algorithm

To diagnose renal function using a biochip capable of detecting SERS and to assess Raman measurements taken from a bilateral renal ischemia model and the feasibility of early diagnosis was done. After generating a bilateral renal ischemia rat model, blood and urine were collected. After confirming the presence of renal injury and function, liquid drops were placed onto a Raman chip whose surface had been enhanced with Au-ZnO nanorods. SERS biomarkers that diffused into the nanogaps were selectively amplified. Raman signals varied based on the severity of the renal function, and these differences were confirmed statistically. These results confirm that renal ischemia leads to renal dysfunction and that surface-enhanced Raman spectroscopy and a machine learning algorithm can be used to track signals in the urine from the release of SERS biomarkers.

Temporal and sex-dependent gene expression patterns in a renal ischemia-reperfusion injury and recovery pig model

Men are more prone to acute kidney injury (AKI) and chronic kidney disease (CKD), progressing to end-stage renal disease (ESRD) than women. Severity and capacity to regenerate after AKI are important determinants of CKD progression, and of patient morbidity and mortality in the hospital setting. To determine sex differences during injury and recovery we have generated a female and male renal ischemia/reperfusion injury (IRI) pig model, which represents a major cause of AKI. Although no differences were found in blood urea nitrogen (BUN) and serum creatinine (SCr) levels between both sexes, females exhibited higher mononuclear infiltrates at basal and recovery, while males showed more tubular damage at injury. Global transcriptomic analyses of kidney biopsies from our IRI pig model revealed a sexual dimorphism in the temporal regulation of genes and pathways relevant for kidney injury and repair, which was also detected in human samples. Enrichment analysis of gene sets revealed five temporal and four sexual patterns governing renal IRI and recovery. Overall, this study constitutes an extensive characterization of the time and sex differences occurring during renal IRI and recovery at gene expression level and offers a template of translational value for further study of sexual dimorphism in kidney diseases.

Involvement of NOX-4/JAK/STAT pathway in the protective effect of aprepitant against diclofenac-induced renal toxicity

AIMS

Aprepitant, a neurokinin-1 (NK1) receptor antagonist, is a clinically approved anti-emetic drug. Recently, inhibition of the NK1 receptor has been reported as a potential nephroprotective strategy. We aimed to assess the pharmacological mechanisms of aprepitant against diclofenac (DIC)-induced renal toxicity.

MAIN METHODS

An in vivo study was conducted using twenty-four male Wistar rats, divided into 4 groups. Aprepitant was administered for 5 days (5 mg/kg/day) with or without DIC which was given on the 4th and 5th days (50 mg/kg, i.p.). At the end of the study, renal function biomarkers, renal oxidative parameters, prostaglandin E (PGE-2), and NADPH oxidase (NOX-4) were measured. Histopathological changes as well as expression of renal inflammatory and apoptotic markers (tumor necrosis factor alpha (TNF-α) and caspase-3) were investigated.

KEY FINDINGS

DIC caused significant renal damage, as evidenced by deterioration of renal functions, oxidative stress, inflammatory and apoptotic markers, and confirmed by histopathological findings. Pretreatment with aprepitant successfully ameliorated and improved all biochemical and molecular parameters induced by DIC. Moreover, aprepitant restored the decrease in renal PGE-2 concentration and inhibited DIC-activated Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling in renal tissues.

SIGNIFICANCE

The protective effect of aprepitant is possibly attributed to its anti-oxidant and anti-inflammatory roles via the NOX-4/JAK/STAT pathway.

Empagliflozin Enhances Autophagy, Mitochondrial Biogenesis, and Antioxidant Defense and Ameliorates Renal Ischemia/Reperfusion in Nondiabetic Rats

Background. Recent meta-analyses have shown that sodium-glucose cotransporter 2 (SGLT-2) inhibitors alleviate chronic kidney disease and acute kidney injury in diabetic patients. In this study, we aimed to investigate the effect of empagliflozin on renal ischemia/reperfusion (I/R) in nondiabetic rats and find the possible mechanisms. Experimental Approach. Eighteen male Wistar rats were randomly divided into three groups, including healthy control, ischemic control, and empagliflozin-treated group. Thirty minutes of bilateral renal ischemia was induced by clamping the renal hilum. Forty-eight hours after reopening the clamps, rats’ blood samples and tissue specimens were collected. Empagliflozin 10 mg/kg was administered by gavage, 2 hours before ischemia and 24 hours after the first dose. Results. I/R injury led to a significant rise in serum creatinine and blood urea nitrogen which was significantly decreased after treatment with empagliflozin. Empagliflozin also alleviated tubulointerstitial and glomerular damage and significantly decreased tissue histology scores. Empagliflozin decreased the increased levels of malondialdehyde, interleukin 1β, and tumor necrosis factor α. SGLT2 inhibition increased the decreased expression of nuclear factor erythroid 2-related factor 2 and PPARG coactivator 1 alpha that conduct antioxidant defense and mitochondrial biogenesis, respectively. Furthermore, empagliflozin markedly increased LC3-II/LC3-I and bcl2/bax ratios, showing its beneficial effect on activation of autophagy and inhibition of apoptosis. Despite its effects on diabetic nephropathy, empagliflozin did not activate the Sestrin2/AMP-activated protein kinase pathway in this study. Conclusion. Empagliflozin improved renal I/R injury in nondiabetic rats in this study by promoting autophagy and mitochondrial biogenesis and attenuation of oxidative stress, inflammation, and apoptosis.

Necrostatin-1 mitigates renal ischemia-reperfusion injury - time dependent- via aborting the interacting protein kinase (RIPK-1)-induced inflammatory immune response

The recently defined necroptosis process participates in the pathophysiology of several tissue injuries. Targeting the necroptosis mediator receptor-interacting protein kinase (RIPK1) by necrostatin-1 in different phases of ischemia-reperfusion injury (IRI) may provide new insight into the protection against renal IRI. The rat groups included (n= 8 in each group); 1) Sham, 2) Renal IRI, 3) Necrostatin-1 treatment 20 min before ischemia induction in a dose of 1.65 mg/kg/intravenous. 4) Necrostatin-1 injection just before reperfusion, 5) Necrostatin-1 injection 20 min after reperfusion establishment, and 6) drug injection at both the pre-ischemia and at reperfusion time in the same dose. Timing dependent, necrostatin-1 diminished RIPK1 (P < 0.001), and aborted the necroptosis induced renal cell injury. Necrostatin-1 decreased the renal chemokine (CXCL1), interleukin-6, intercellular adhesion molecule (ICAM-1), myeloperoxidase, and the nuclear factor (NFκB), concomitant with reduced inducible nitric oxide synthase (iNOS), inflammatory cell infiltration, and diminished cell death represented by apoptotic cell count and the BAX/Bcl2 protein ratio. In group six, the cell injury was minimum and the renal functions (creatinine, BUN, and creatinine clearance) were almost normalized. The inflammatory markers were diminished (P < 0.001) compared to the IRI group. The results were confirmed by histopathological examination. In conclusion, RIPK1 inhibition ameliorates the inflammatory immune response induced by renal IRI. The use of two doses was more beneficial as the pathophysiology of cell injury is characterized.

Autologous omentum transposition for regeneration of a renal injury model in rats

BACKGROUND

After renal trauma, surgical treatment is vital, but sometimes there may be loss of function due to fibrosis. This study aimed to evaluate the effect of autologous omentum flaps on injured renal tissues in a rat model.

METHODS

A total of 30 Wistar albino rats were included and randomly divided equally into a control group and four intervention groups. Iatrogenic renal injuries were repaired using a surgical technique (primary repair 1 group and primary repair 2 group) or transposition of the autologous omentum (omentum repair 1 group and omentum repair 2 group). Blood samples were taken preoperatively and on the 1st and 7th postoperative days in all groups and on the 18th postoperative day in the control and two intervention groups. All rats were sacrificed on the 7th or 18th day postoperatively, and their right kidneys were taken for histopathological evaluation.

RESULTS

The mean urea level significantly decreased from day 1 to day 7 and from day 1 to day 18 in the omentum repair 2 group (P = 0.005 and P = 0.004, respectively). There were no other significant changes in urea or creatinine levels within the intervention groups (P > 0.05). There was no significant correlation between the urea and creatinine levels and the histological scores (P > 0.05). The primary repair 1 and 2 groups had significantly higher median granulation and inflammation scores in the kidney specimen than the control and omentum repair groups (P < 0.05). The omentum repair 2 group had significantly lower median granulation and inflammation scores in the surrounding tissues than the primary repair 2 group (P < 0.05). The completion score for the healing process in the kidney specimen was significantly higher in the omentum repair groups than in the primary repair groups (P < 0.05). The omentum repair 2 group had significantly lower median granulation and inflammation scores in the surrounding tissues than the primary repair 2 group (P < 0.05). Granulation degree in the kidney specimen was strongly and positively correlated with the inflammation degree (r = 0.824, P < 0.001) and foreign body reaction in the kidney specimen (r = 0.872, P < 0.001) and a strong and negative correlation with the healing process completion score in the kidney (r = - 0.627, P = 0.001). Inflammation degree in the kidney specimen was strongly and positively correlated with the foreign body reaction in the kidney specimen (r = 0.731, P = 0.001) and strongly and negatively correlated with the healing process completion score in the kidney specimen (r = - 0.608, P = 0.002).

CONCLUSION

Autologous omentum tissue for kidney injury repair attenuated inflammation and granulation. Additionally, the use of omental tissue to facilitate healing of kidney injury may theoretically lead to a more effective healing process and reduced fibrosis and tissue and function loss.

An Ovine Model of Hemorrhagic Shock and Resuscitation, to Assess Recovery of Tissue Oxygen Delivery and Oxygen Debt, and Inform Patient Blood Management

BACKGROUND

Aggressive fluid or blood component transfusion for severe hemorrhagic shock may restore macrocirculatory parameters, but not always improve microcirculatory perfusion and tissue oxygen delivery. We established an ovine model of hemorrhagic shock to systematically assess tissue oxygen delivery and repayment of oxygen debt; appropriate outcomes to guide Patient Blood Management.

METHODS

Female Dorset-cross sheep were anesthetized, intubated, and subjected to comprehensive macrohemodynamic, regional tissue oxygen saturation (StO2), sublingual capillary imaging, and arterial lactate monitoring confirmed by invasive organ-specific microvascular perfusion, oxygen pressure, and lactate/pyruvate levels in brain, kidney, liver, and skeletal muscle. Shock was induced by stepwise withdrawal of venous blood until MAP was 30 mm Hg, mixed venous oxygen saturation (SvO2) < 60%, and arterial lactate >4 mM. Resuscitation with PlasmaLyte® was dosed to achieve MAP > 65 mm Hg.

RESULTS

Hemorrhage impacted primary outcomes between baseline and development of shock: MAP 89 ± 5 to 31 ± 5 mm Hg (P < 0.01), SvO2 70 ± 7 to 23 ± 8% (P < 0.05), cerebral regional tissue StO2 77 ± 11 to 65 ± 9% (P < 0.01), peripheral muscle StO2 66 ± 8 to 16 ± 9% (P < 0.01), arterial lactate 1.5 ± 1.0 to 5.1 ± 0.8 mM (P < 0.01), and base excess 1.1 ± 2.2 to -3.6 ± 1.7 mM (P < 0.05). Invasive organ-specific monitoring confirmed reduced tissue oxygen delivery; oxygen tension decreased and lactate increased in all tissues, but moderately in brain. Blood volume replacement with PlasmaLyte® improved primary outcome measures toward baseline, confirmed by organ-specific measures, despite hemoglobin reduced from baseline 10.8 ± 1.2 to 5.9 ± 1.1 g/dL post-resuscitation (P < 0.01).

CONCLUSION

Non-invasive measures of tissue oxygen delivery and oxygen debt repayment are suitable outcomes to inform Patient Blood Management of hemorrhagic shock, translatable for pre-clinical assessment of novel resuscitation strategies.

Effect of Enhydra fluctuans on Kidney Function in Alloxan-induced Diabetic Rats

AIM: The aim of this study was to explore the effect of n-hexane fraction of Enhydra fluctuans aerial on kidney function in alloxan induced diabetic rats. METHODS: Five groups of diabetic Wistar rats were studied: Group 1 was given 0.5% Na-CMC (G0), group 2 was given glibenclamide 0.45 mg/kg (G1), groups 3, 4, and 5 were given a dose of n-hexane fraction 57.03, 114.06, and 171.09 mg/kg respectively. The experiment was completed in 21 days. Blood glucose was estimated on day 0 and day 21 of treatment. Histology of kidney, creatinine, and blood urea nitrogen (BUN) was examined. ANOVA was used to evaluate quantitative data, which was then followed by Duncan's new multiple range test (p < 0.05). RESULTS: Our results demonstrate that n-hexane fraction dosages of 57.03 mg/kg and 114,06 mg/kg significantly improved blood glucose profile, BUN, and creatinine in diabetic rats. Moreover, the dosage of 57.03 mg/kg is effective to counteract necrosis and fibrosis of kidney cells.   CONCLUSION: Our findings revealed that the administration of the n-hexane fraction of E. fluctuans aerial improved the kidney function of diabetic rats, especially at the dosage of 57.03 mg/kg. Therefore, E. fluctuans can be relied upon to be a drug to prevent the development of diabetes mellitus and diabetic nephropathy.

Edible Bird Nest Protects the Kidney From Gentamicin Induced Acute Tubular Necrosis

Every year, there are about 13.3 million cases of acute kidney injury (AKI). Although AKI is a preventable and treatable disease, if left untreated, it has high risk of multiple organ failure and progression to end stage kidney disease. Acute tubular necrosis (ATN) has been recognised as one of the major causes of AKI. Till to date, there is no effective supplement or medication in treating or reversing AKI. Most of the treatment strategies involve preventative measure to minimise the occurrence of AKI or to reverse the cause of AKI. Hence one of the primary area of research interests is to explore the potential treatment for AKI. Edible bird nests (EBN) are edible food produce by the swiftlet’s saliva, which is rich in sialic acids. Sialic acids are monosaccharides that play a vital role in maintaining the integrity and proper function of the human organs, including kidneys. EBN also contains epidermal growth factor, which is widely believed to have rejuvenation and tissue repairing properties. We initiate this study to study the potential reno-protective effect of edible bird’s nests by studying the Wistar rat model of gentamicin-induced AKI. Besides renal profiles, renal histology was also semiquantitatively assessed. In our study, pre-treatment with EBN prevented and ameliorated the gentamicin-induced AKI. To a lesser extent, post-treatment with EBN also protected the kidney from the toxic effect of gentamicin. Our findings are highly indicative that EBN possesses reno-protective properties.

Remote liver injury following acute renal ischaemia-reperfusion: involvement of circulating exosomal miR-687 and regulation by thymoquinone

NEW FINDINGS

What is the central question of this study? What is the role of circulating exosomal miR-687 in remote hepatic injury following renal ischaemia-reperfusion injury (IRI) and does thymoquinone have a modulatory impact? What is the main finding and its importance? Exosomal miR-687 was expressed in renal IRI, entered the circulation and was deposited in the liver. Liver exosomal miR-687 was correlated with liver inflammation and apoptosis. Thymoquinone aborted the renal production of exosomal miR-687 and its further circulation to the liver.

ABSTRACT

The pathophysiology of remote hepatic injury following acute renal ischaemia-reperfusion injury (IRI) is of particular clinical interest. Secreted small non-coding microRNA (miRs) are thought to exist in exosome-encapsulated form. Thymoquinone (TQ) is the main bioactive ingredient of Nigella sativa and has several renoprotective actions. We expected exosomal miR-687 to be relevant as it could act as a humoral mediator, with possible modulation by TQ. Thirty adult male Wister albino rats were assigned to three groups (n = 10); (1) sham-operated, (2) renal ischaemia-reperfusion injury (IRI), and (3) renal IRI pre-treated with TQ 10 mg/kg/day i.v. (TQ-IRI) for 10 days in addition to a dose administered at reperfusion onset. Following 24 h of reperfusion, the IRI group showed renal tissue hypoxia-inducible factor upregulation (P < 0.001). Electron microscopy images of exosomes and analysis of miR-687 revealed elevated levels, which appeared in the circulation. Large amounts of exosomal miR-687 were transmitted to the liver tissue. In the IRI group, liver transaminases (alanine aminotransferase, aspartate aminotransferase) were markedly (P < 0.001) elevated. The hepatic tissue inflammatory markers (vascular cell adhesion molecule-1, myeloperoxidase, monocyte chemotactic protein-1 and nuclear factor-κB) were upregulated (P < 0.001) accompanied with elevated caspase-3. TQ suppressed (P < 0.001) the renal expression and release of exosomal miR-687 into the circulation and its further deposition in the liver tissue; consequently, TQ diminished (P < 0.001) liver tissue inflammation and cellular apoptosis. The results were confirmed by histological tissue assessment. In conclusion, exosomal miR-687 liberated from injured renal tissues into the circulation may be an important factor in inducing remote hepatic injury. Exosomal miR-687 inhibition by TQ protected both renal and hepatic tissues from injury.

Rat Model Investigation on the Role of Biomarkers in Hepatic Ischemia-Reperfusion Injury

OBJECTIVES

Liver function is affected by ischemiareperfusion. Ischemia-reperfusion injury to the liver often follows hepatobiliary surgery. Here, we investigated biomarkers of liver ischemia-reperfusion injury using an animal model.

MATERIALS AND METHODS

For this study, 24 male Sprague Dawley rats (146-188 g) were divided into 4 groups: group A was the control group, group B was the partial hepatic ischemia-reperfusion group, group C was the total hepatic ischemia-reperfusion group, and group D was the intermittent total hepatic ischemiareperfusion group. Laboratory liver function levels were measured before ischemia, after ischemia, and after reperfusion. We used liver and renal biopsies for histopathological examination at the end of the study.

RESULTS

After clamping and reperfusion, alanine aminotransferase and cystatin C levels in groups B, C, and D were significantly higher than levels in group A. In group B, after clamping, neutrophil gelatinaseassociated lipocalin levels were higher than in groups A and D, with significantly higher level than in group D after reperfusion. Neutrophil gelatinase-associated lipocalin levels decreased significantly in groups B, C, and D after reperfusion. There was significantly greater hepatic damage in groups B, C, and D compared with group A but no significant differences in renal injury scores among the groups. There was a significant positive correlation between hepatic damage and renal injury. With regard to histopathological examination versus laboratory results, a statistically significant positive correlation was shown between grade of hepatic damage and serum alanine aminotransferase and cystatin C levels. Similarly, there was a positive correlation between renal damage score and alanine aminotransferase level.

CONCLUSIONS

In our animal model, alanine amino - transferase and cystatin C levels tended to increase with ischemia-reperfusion injury levels but neutrophil gelatinase-associated lipocalin decreased during reperfusion. In liver ischemia, we suggest that neutrophil gelatinase-associated lipocalin may be an important biomarker for distinguishing the reperfusion phase.

IL-1β primed mesenchymal stromal cells moderate hemorrhagic shock-induced organ injuries

Background

Organ damages following hemorrhagic shock (HS) have been partly attributed to an immunological dysfunction. The current challenge in the management of HS patients is to prevent organ injury-induced morbidity and mortality which currently has not etiological treatment available. Mesenchymal stromal cells (MSC) are used in clinical cell therapy for immunomodulation and tissue repair. In vitro priming is often used to improve the immunomodulation efficiency of MSC before administration.

Objective

Assess the effect of naive MSC (MSCn) or interleukin (IL)-1β primed (MSCp) treatment in a context of HS-induced organ injury.

Methods

Rats underwent fixed pressure HS and were treated with allogenic MSCn or MSCp. Liver and kidney injuries were evaluated 6h later by histological and biochemical analysis. Whole blood was collected to measure leukocytes phenotypes. Then, in vitro characterization of MSCn or MSCp was carried out.

Results

Plasma creatinine, blood urea nitrogen, and cystatin C were decrease by MSCp infusion as well as kidney injury molecule (KIM)-1 on histological kidney sections. Transaminases, GGT, and liver histology were normalized by MSCp. Systemic cytokines (IL-1α, IL-6, and IL-10) as well as CD80, 86, and PD-1/PDL-1 axis were decreased by MSCp on monocytes and granulocytes. In vitro, MSCp showed higher level of secreted immunomodulatory molecules than MSCn.

Conclusion

An early administration of MSCp moderates HS-induced kidney and liver injury. IL-1β priming improves MSC efficiency by promoting their immunomodulatory activity. These data provide proof of concept that MSCp could be a therapeutic tool to prevent the appearance of organs injury following HS.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02505-4.

Ameliorative effect of Mangosteen (Garcinia mangostana L.) peel infusion on the histopathological structures of the liver and kidney of rats (Rattus norvegicus Berkenhout, 1769) after H2O2 induction

BACKGROUND AND AIM

Hydrogen peroxide (H2O2) is a free radical, widely use as a food preservative, may cause adverse effects to the body. Mangosteen contains various antioxidants may scavenge free radical produced by H2O2. This study examined the effects of mangosteen peel infusion on the liver and kidney of rats after H2O2 induction.

MATERIALS AND METHODS

Thirty-six female Wistar rats were divided into six groups: Negative control, positive control (1% H2O2), as well as mangosteen peel infusion groups at a concentration of 0.25; 0.5; 1, and 2%. H2O2 induction was administered orally every day for 2 months followed by mangosteen peel infusion treatment (1 month) after H2O2 induction for 1 month. At the end of the experiment, the rats were sacrificed. The liver and kidney of each rat were collected for reactive oxygen species (ROS) and histopathological examinations. Furthermore, blood was collected for creatinine examination.

RESULTS

H2O2 induction caused the highest ROS level elevation in the positive control group which was treated with H2O2 only. Meanwhile, 2% of mangosteen peel infusion returned the ROS levels to normal. It was also observed that mangosteen peel infusion restored creatinine levels to normal. Furthermore, 2% of mangosteen peel infusion improved the histopathological structure of the liver and kidneys after H2O2 induction.

CONCLUSION

Mangosteen peel infusion especially at a concentration of 2% has the potential to improve liver and kidney structure and functions after H2O2 induction.

Effect of NAD+ boosting on kidney ischemia-reperfusion injury

Acute kidney injury (AKI) is associated with a very high mortality and an increased risk for progression to chronic kidney disease (CKD). Ischemia-reperfusion injury (IRI) is a model for AKI, which results in tubular damage, dysfunction of the mitochondria and autophagy, and in decreased cellular nicotinamide adenine dinucleotide (NAD⁺) with progressing fibrosis resulting in CKD. NAD⁺ is a co-enzyme for several proteins, including the NAD⁺ dependent sirtuins. NAD⁺ augmentation, e.g. by use of its precursor nicotinamide riboside (NR), improves mitochondrial homeostasis and organismal metabolism in many species. In the present investigation the effects of prophylactic administration of NR on IRI-induced AKI were studied in the rat. Bilateral IRI reduced kidney tissue NAD⁺, caused tubular damage, reduced α-Klotho (klotho), and altered autophagy flux. AKI initiated progression to CKD, as shown by induced profibrotic Periostin (postn) and Inhibin subunit beta-A, (activin A / Inhba), both 24 hours and 14 days after surgery. NR restored tissue NAD⁺ to that of the sham group, increased autophagy (reduced p62) and sirtuin1 (Sirt1) but did not ameliorate renal tubular damage and profibrotic genes in the 24 hours and 14 days IRI models. AKI induced NAD⁺ depletion and impaired autophagy, while augmentation of NAD⁺ by NR restored tissue NAD⁺ and increased autophagy, possibly serving as a protective response. However, prophylactic administration of NR did not ameliorate tubular damage of the IRI rats nor rescued the initiation of fibrosis in the long-term AKI to CKD model, which is a pivotal event in CKD pathogenesis.

Determination of a microRNA signature of protective kidney ischemic preconditioning originating from proximal tubules

Ischemic preconditioning (IPC) is effective in limiting subsequent ischemic acute kidney injury in experimental models. MicroRNAs are an important class of post-transcriptional regulator and show promise as biomarkers of kidney injury. We evaluated the time- and dose-dependence of benefit from IPC in a rat model of functional (bilateral) ischemia–reperfusion injury (IRI). We found optimal protection from subsequent injury following short, repetitive sequences of preconditioning insult. We subsequently used hybridization array and microRNA sequencing to characterize microRNA signatures of protective IPC and of IRI. These approaches identified a profile of microRNA changes consequent on IRI, that were limited by prior IPC. To localize these signals within the kidney, we used laser capture microdissection and RT-qPCR to measure microRNA abundance in nephron segments, pinpointing microRNA changes principally to glomeruli and proximal tubules. Our data describe a unique microRNA signature for IRI in the rat kidney. Pulsatile IPC reduces kidney damage following IRI and diminishes this microRNA signal. We have also identified candidate microRNAs that may act as biomarkers of injury and therapeutic targets in this context.

Entacapone scavenges peroxynitrite and protects against kidney and liver injuries induced by renal ischemia/reperfusion in rats

BACKGROUND

Acute kidney injury (AKI), secondary to renal ischemia/reperfusion (I/R), is a serious problem associated with high mortality. The pathophysiology of AKI after renal I/R involves peroxynitrite production; hence, scavenging this metabolite may rescue AKI. Entacapone is a catechol-O-methyl transferase (COMT) inhibitor which elicits antioxidant activity by scavenging peroxynitrite. Therefore, we hypothesized that the peroxynitrite scavenging activity of entacopone protects against AKI after renal I/R injury in rats.

METHODS

Male Wistar rats were given either entacapone or a well-known peroxynitrite scavenger (FeTPPS) daily for 10 days before I/R procedures. I/R was induced by occluding both renal pedicles for 45 min followed by reperfusion for 24 h.

RESULTS

Pre-treatment with either entacapone or FeTPPS improved renal function as indicated by a significant reduction in serum creatinine and urea when compared to I/R group (P < 0.05). I/R injury increased renal levels of NO (4-folds, P < 0.05), iNOS (4-folds, P < 0.05), and 3-nitrotyrosine (5-folds, P < 0.05) compared to sham control. These effects were abrogated in animals pre-treated with entacapone or FeTPPS before being subjected to I/R (P < 0.05). In addition, entacapone or FeTPPS significantly inhibited I/R-induced elevation in renal TNF-α levels (78% and 58%, respectively) and caspase-3 activity (72% and 56%, respectively) indicating the reduction of both inflammation and apoptosis in the kidney (P < 0.05). The two drugs also improved kidney and liver functions in rats with renal I/R injury.

CONCLUSION

Our study showed that entacapone and FeTPPS protected against AKI and remote liver damage associated with renal I/R and this effect might be due to scavenging peroxynitrite and reducing nitrosative stress.

Bioactive glass-biopolymers‑gold nanoparticle based composites for tissue engineering applications

Biomaterials based on bioactive glass with gold nanoparticle composites have many applications in tissue engineering due to their tissue regeneration and angiogenesis capacities. The objectives of the study were to develop new composites using bioactive glass with gold nanospheres (BGAuSP) and gold nanocages (BGAuIND), individually introduced in alginate-pullulan (Alg-Pll) polymer, to evaluate their biocompatibility potential, and to compare the obtained results with those achieved when β-tricalcium phosphate-hydroxyapatite (βTCP/HA) replaced the BG. The novel composites underwent structural and morphological characterization followed by in vitro viability testing on fibroblast and osteoblast cell lines. Additionally, the biomaterials were subcutaneously implanted in Sprague Dawley rats, for in vivo biocompatibility assessment during 3 separate time frames (14, 30 and 60 days). The biological effects were evaluated by histopathology and immunohistochemistry. The physical characterization revealed the cross-linking between polymers and glasses/ceramics and demonstrated a suitable thermal stability for sterilization processes. The in vitro assays demonstrated adequate form, pore size of composites ranging from few micrometers up to 100 μm, while the self-assembled apatite layer formed after simulated body fluid immersion confirmed the composites' bioactivity. Viability assays have highlighted optimal cellular proliferation and in vitro biocompatibility for all tested composites. Furthermore, based on the in vivo subcutaneous analyses the polymer composites with BGAuNP have shown excellent biocompatibility at 14, 30 and 60 days, exhibiting marked angiogenesis while, tissue proliferation was confirmed by high number of Vimentin positive cells, in comparison with the polymer composite that contains βTCP/HA, which induced an inflammatory response represented by a foreign body reaction. The obtained results suggest promising, innovative, and biocompatible composites with bioactive properties for future soft tissue and bone engineering endeavours.

Renoprotective effect of platelet-rich plasma in obstructive uropathy

PURPOSE

To investigate the effect of platelet-rich plasma (PRP) in reducing renal injury in ureteral obstruction.

METHODS

Twenty-four Wistar Albino rats were randomized and divided into four groups as the donor (n = 6), sham (n = 6), saline (n = 6), and PRP (n = 6). Blood was obtained from the donor group by cardiac puncture and PRP was prepared. 2 cc blood was sampled from other groups to measure blood-urea nitrogen and creatinine levels. Baseline renal scintigraphy was performed. An abdominal midline incision was made and the left ureter was exposed in the sham group. Saline infusion was given to the kidneys of the saline group after left ureteral obstruction, while PRP was given to the PRP group. On postoperative Day 7, control biochemical and scintigraphic evaluations were performed and left nephrectomies were done. Left kidneys were evaluated histopathologically.

RESULTS

DMSA measurements in the sham group were found to be significantly higher than the saline and PRP groups (p = 0.001 and p = 0.024, respectively). There were no significant differences between the saline and PRP groups (p = 0.525 and p > 0.05, respectively). Histopathologically, no significant difference was observed between the saline and PRP groups (p = 0.320), while the scores of the sham group were significantly higher than the saline and PRP groups (p = 0.02 and p = 0.001, respectively).

CONCLUSION

Our study results suggest that PRP may be effective in preventing ureteral obstruction-induced renal injury.

Protective effect of cordycepin on experimental renal ischemia/reperfusion injury in rats

AIM

To date, various molecules have been investigated to reduce the effect of renal ischemia/reperfusion (I/R) injury. However, none have yet led to clinical use. The present study aimed to investigate the protective effect of cordycepin (C) on renal I/R injury in an experimental rat model.

MATERIALS AND METHODS

Twenty-four mature Sprague Dawley female rat was randomly divided into three groups: Sham, I/R, I/R+C. All animals underwent abdominal exploration. To induce I/R injury, an atraumatic vascular bulldog clamp was applied to the right renal pedicle for 60 minutes (ischemia) and later clamp was removed to allow reperfusion in all rats, except for the sham group. In the I/R + C group, 10 mg/kg C was administered intraperitoneally, immediately after reperfusion. After 4 hours of reperfusion, the experiment was terminated with right nephrectomy. Histological studies and biochemical analyses were performed on the right nephrectomy specimens. EGTI (endothelial, glomerular, tubulointerstitial) histopathology scoring and semi-quantitative analysis of renal cortical necrosis were used for histological analyses and superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA), total oxidant status (TOS) for biochemical analyses.

RESULTS

Histopathological examination of the tissue damage revealed that all kidneys in the sham group were normal. The I/R group had higher histopathological scores than the I/R + C group. In the biochemical analysis of the tissues, SOD, MDA, TOS values were found to be statistically different in the I/R group compared to the I/R + C group (p: 0.004, 0.004, 0.001 respectively).

CONCLUSIONS

Intraperitoneal cordycepin injection following ischemia preserve renal tissue against oxidative stress in a rat model of renal I/R injury.

Pre-arrest doxycycline protects donation after circulatory death kidneys

Kidney injury during donation after circulatory determination of death (DCDD) includes warm ischemic (WI) injury from around the time of asystole, and cold ischemic (CI) injury during cold preservation. We have previously shown that Matrix Metalloproteinases (MMPs) are involved in CI injury and that Doxycycline (Doxy), an antibiotic and known MMP inhibitor, protects the transplant kidney during CI. The purpose of our study was to determine if Doxy given before asystole can also prevent injury during WI. A rat model of DCDD was used, including Control, Preemptive Doxy (45 mg/kg iv), and Preemptive and Perfusion (100 microM) Doxy groups. Thirty minutes after asystole, both kidneys were removed. The left kidney was perfused at 4 °C for 22 h, whereas the right was used to establish the degree of warm ischemic injury prior to cold preservation. MMP-2 in the perfusate was significantly reduced in both treatment groups [Control 43.7 ± 7.2 arbitrary units, versus Preemptive Doxy group 23.2 ± 5.5 (p = 0.03), and 'Preemptive and Perfusion' group 18.0 ± 5.6 (p = 0.02)]. Reductions in NGAL, LDH, and MMP-9 were also seen. Electron microscopy showed a marked reduction in mitochondrial injury scores in the treatment groups. Pre-arrest Doxy was associated with a reduction in injury markers and morphologic changes. Doxy may be a simple and safe means of protecting transplant kidneys from both WI and CI.

A Novel Preservation Solution Containing Quercetin and Sucrose for Porcine Kidney Transplantation

In organ transplantation, the University of Wisconsin (UW) solution has been the gold standard for organ preservation. Quercetin (Que) has numerous antioxidant and anti-inflammatory activities, and sucrose (Suc) may be effective for cold storage (CS). This study aimed to investigate the in vitro protective effect of Que and Suc on cold injury to the kidney and to determine whether Que + Suc could improve ischemia-reperfusion injury during CS and hypothermic oxygenated perfusion (HOPE) in autologous transplantation models.

METHODS

BHK-21 cells were stored at 4°C for 3 days in UW solution for CS/machine perfusion (CS/MP-UW) with Que (33.1 μM, 3.3 μM, 0.33 μM) and Suc (0.1 M). In a porcine model of renal autologous transplantation, left kidney grafts were preserved under 3 conditions: group 1, CS preservation for 24 hours; group 2, CS preservation for 22 hours and HOPE with CS/MP-UW solution for 2 hours; and group 3, identical preservation as group 2, with Que and Suc added to the solution. Animals were euthanized on day 7 after autologous transplantation.

RESULTS

After 3 days of CS preservation, the CS/MP-UW solution with Que (33.1 μM, 3.3 μM) and Suc showed significant cell protection against cold injury. In the porcine model of renal autologous transplantation, the last blood Cre level and the blood lipid hydroperoxide on posttransplantation day 2 were significantly different between group 1 and group 3. Moreover, the total endothelial, glomerular, tubular, interstitial (EGTI) histology score in the kidney tissue was also significantly different. Regarding the change in renal resistance in HOPE, the decrease observed in group 3 was significantly larger than that in group 2.

CONCLUSIONS

Our results suggest that the addition of Que and Suc to a UW solution can improve kidney preservation and could potentially enhance the outcome of kidney transplantation.

A Study of Carry-Over and Histopathological Effects after Chronic Dietary Intake of Citrinin in Pigs, Broiler Chickens and Laying Hens

Citrinin (CIT) is a polyketide mycotoxin occurring in a variety of food and feedstuff, among which cereal grains are the most important contaminated source. Pigs and poultry are important livestock animals frequently exposed to mycotoxins, including CIT. Concerns are rising related to the toxic, and especially the potential nephrotoxic, properties of CIT. The purpose of this study was to clarify the histopathological effects on kidneys, liver, jejunum and duodenum of pigs, broiler chickens and laying hens receiving CIT contaminated feed. During 3 weeks, pigs (n = 16) were exposed to feed containing 1 mg CIT/kg feed or to control feed (n = 4), while 2 groups of broiler chickens and laying hens (n = 8 per group) received 0.1 mg CIT/kg feed (lower dose group) and 3 or 3.5 mg CIT/kg feed (higher dose group), respectively, or control feed (n = 4). CIT concentrations were quantified in plasma, kidneys, liver, muscle and eggs using a validated ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method. Kidneys, liver, duodenum and jejunum were evaluated histologically using light microscopy, while the kidneys were further examined using transmission electron microscopy (TEM). Histopathology did not reveal major abnormalities at the given contamination levels. However, a significant increase of swollen and degenerated mitochondria in renal cortical cells from all test groups were observed (p < 0.05). These observations could be related to oxidative stress, which is the major mechanism of CIT toxicity. Residues of CIT were detected in all collected tissues, except for muscle and egg white from layers in the lowest dose group, and egg white from layers in the highest dose group. CIT concentrations in plasma ranged between 0.1 (laying hens in lower dose group) and 20.8 ng/mL (pigs). In tissues, CIT concentrations ranged from 0.6 (muscle) to 20.3 µg/kg (liver) in pigs, while concentrations in chickens ranged from 0.1 (muscle) to 70.2 µg/kg (liver). Carry-over ratios from feed to edible tissues were between 0.1 and 2% in pigs, and between 0.1 and 6.9% in chickens, suggesting a low contribution of pig and poultry tissue-derived products towards the total dietary CIT intake for humans.

Evaluation of renal ischemia-reperfusion injury by magnetic resonance imaging texture analysis: An experimental study

PURPOSE

To explore the value of MRI texture analysis in evaluating the presence and severity of early renal ischemia-reperfusion injury (IRI).

METHODS

Healthy New Zealand rabbits were used (IRI group, N = 54; control group, N = 8). Rabbits in the IRI group underwent left renal artery clamping for 60 minutes. Magnetic resonance imaging was performed before and at 1, 12, 24, and 48 hours after IRI. The relationship between MRI texture features and histopathology parameters was assessed using Pearson's correlation coefficients. The diagnostic performance of texture features in kidney differentiation at different time points was assessed by receiver operating characteristic curve analysis.

RESULTS

T₂ WI_S(3,-3)Inverse_Difference_Moment had the strongest correlation with brush border destruction, tubular epithelial edema, necrosis, and cast (r = 0.56, -0.58, 0.62, and 0.69, respectively; all P < .001). BOLD_S(4,-4)Correlation had the strongest correlation with interstitial inflammatory cell infiltration (r = 0.63, P < .001). SWI_S(4,4)Difference_Entropy had the strongest correlation with microvessel density (r = 0.61, P < .001). The areas under the curve for T₂ WI_S(3,-3)Inverse_Difference_Moment, SWI_S(4,4)Difference_Entropy, and BOLD_S(4,-4)Correlation in kidney differentiation before IRI and that at 1 and 12 hours after reperfusion were 0.76, 0.72, and 0.70, respectively; the values before IRI and at 24 and 48 hours after reperfusion were 0.84, 0.81, and 0.69, respectively. The area under the curve for T₂ WI_S(3,-3)Inverse_Difference_Moment in kidney differentiation at 1 and 12 hours after reperfusion and that at 24 and 48 hours after reperfusion was 0.66.

CONCLUSION

Magnetic resonance imaging texture analysis can be used for evaluating the presence and severity of early renal IRI.