Renal Oxidative Stress Research Articles

Renal Inflammation, Oxidative Stress, and Metabolic Abnormalities During the Initial Stages of Hypertension in Spontaneously Hypertensive Rats

Background: Hypertension is a major cause of mortality worldwide. The kidneys play a crucial role in regulating blood pressure and fluid volume. The relationship between the kidneys and hypertension is complex, involving factors such as the renin–angiotensin system, oxidative stress, and inflammation. This study aims to assess the levels of inflammatory markers, oxidative stress, and metabolic factors in the kidneys, focusing on their potential role in early renal damage and their association with the development of hypertension. Methods: This study was designed to compare the levels of selected inflammatory markers, e.g., interleukins, tumor necrosis factor-α (TNF-α), transforming growth factor, and serine/threonine-protein (mTOR); oxidative stress markers such as malondialdehyde, sulfhydryl group, and glucose (GLC); and metabolic markers among other enzymes, such as alanine transaminase (ALT), aspartate transaminase (AST), hexokinase II (HK-II), and hypoxia-inducible factor-1α (HIF-1α), as well as creatinine in the kidneys of spontaneously hypertensive rats (SHR/NCrl, n = 12) and Wistar Kyoto rats (WKY/NCrl, n = 12). Both juvenile (5 weeks old) and maturing (10 weeks old) specimens were examined using spectrophotometric methods, e.g., ELISA. Results: Juvenile SHRs exhibited reduced renal levels of all studied cytokines and chemokines, with lower oxidative stress and deficits in the mTOR and HK-II levels compared to the age-matched WKYs. Maturing SHRs showed increased renal levels of interleukin-1β (IL-1β), IL-6, IL-18, and TNF-α, alongside elevated carbonyl stress and increased HIF-1α as opposed to their control peers. The levels of all other studied markers were normalized in these animals, except for ALT (increased), ALP, and GLC (both reduced). Conclusions: This study underscores the significant impact of inflammatory, oxidative stress, and metabolic marker changes on renal function. Juvenile SHRs display lower marker levels, indicating an immature immune response and potential subclinical kidney damage that may contribute to hypertension development. In contrast, mature SHRs exhibit chronic inflammation, oxidative dysregulation, and metabolic disturbances, suggesting cellular damage. These changes create a feedback loop that worsens kidney function and accelerates hypertension progression, highlighting the kidneys’ crucial role in both initiating and exacerbating this condition.

Exercise as a therapeutic approach to alleviate diabetic kidney disease: mechanisms, clinical evidence and potential exercise prescriptions

Diabetic kidney disease (DKD) is a global and severe complication that imposes a significant burden on individual health, families, and society. Currently, the main treatment approaches for DKD include medication, blood glucose control, protein-restricted diet, and blood pressure management, all of which have certain limitations. Exercise, as a non-pharmacological intervention, has attracted increasing attention. This review introduces the mechanisms and clinical evidence of exercise on DKD, and proposes potential exercise prescriptions. Exercise can improve blood glucose stability related to DKD and the renin-angiotensin-aldosterone system (RAAS), reduce renal oxidative stress and inflammation, enhance the crosstalk between muscle and kidneys, and improve endothelial cell function. These mechanisms contribute to the comprehensive improvement of DKD. Compared to traditional treatment methods, exercise has several advantages, including safety, effectiveness, and no significant side effects. It can be used as an adjunct therapy to medication, blood glucose control, protein-restricted diet, and blood pressure management. Despite the evident benefits of exercise in DKD management, there is still a lack of large-scale, long-term randomized controlled trials to provide more evidence and develop exercise guidelines for DKD. Healthcare professionals should actively encourage exercise in DKD patients and develop personalized exercise plans based on individual circumstances.

The integrated effect of roflumilast and selenium nanoparticles on nephrotoxicity generated by cisplatin through the regulation of the antioxidant and apoptotic pathways

AimThe current investigations aimed to investigate the potential synergistic effect of Roflumilast (ROF) and Selenium nanoparticles (SeNPs) administration on Cisplatin (Cis) -induced nephrotoxicity. Materials and methodsFifty male rats were divided into five groups; Control group: animals were administered 0.9 % saline solution. Cis group: animals were injected with a single dose of 6 mg/kg. ROF group: Rats received a dosage of 1.2 mg/kg orally daily for 11 days. SeNPs group: animals orally received 0.5 mg/kg of ROF daily for 11 days. The ROF + SeNPs group was administered both after receiving a Cis injection for 11 days. Animals were sacrificed at 5 and 11 days, and the urine and blood samples were collected on day 5 and day 11 for chemical analysis, while kidney samples were obtained for molecular, histological, and immunohistochemical studies. ResultsThe levels of serum creatinine, Blood urea nitrogen (BUN), and total protein were elevated in the Cis group compared to the control group (p < 0.05). While the combination of ROF and SeNPs dramatically decreased these values after 5 and 11 days (p < 0.05). In addition, Cis caused renal oxidative stress by elevating MDA levels and suppressing the activities of SOD, GSH, and CAT. Similarly, these effects were modulated by ROF and SeNPs after 11 days (p < 0.05). Furthermore, the concurrent administration of ROF and SeNPs resulted in a significant increase in the expression of HO-1, Nrf2, and Bcl2, while decreasing the expression of BAX and IL-6 compared to the Cis group after 11 days (P < 0.05). ConclusionThe study showed that both ROF and SeNPs had significant therapeutic potential in reducing the pathological alterations caused by Cis.

Asiaticoside improves diabetic nephropathy by reducing inflammation, oxidative stress, and fibrosis: An in vitro and in vivo study

BACKGROUND Diabetic nephropathy (DN) is a severe microvascular complication of diabetes characterized by inflammation, oxidative stress, and renal fibrosis. Asiaticoside (AC) exhibits anti-inflammatory, antioxidant, and anti-fibrotic properties, suggesting potential therapeutic benefits for DN. This study aimed to investigate the protective effects of AC against DN and elucidate the underlying mechanisms involving the nuclear factor erythroid 2-related factor 2 (NRF2)/heme oxygenase-1 (HO-1) antioxidant pathway. AIM To investigate the renoprotective effects of AC against DN and elucidate the role of the NRF2/HO-1 pathway. METHODS The effects of AC on high glucose (HG)-induced proliferation, inflammation, oxidative stress, and fibrosis were evaluated in rat glomerular mesangial cells (HBZY-1) in vitro . A streptozotocin-induced DN rat model was established to assess the in vivo impact of AC on renal injury, inflammation, oxidative stress, and fibrosis. The involvement of the NRF2/HO-1 pathway was examined using pharmacological inhibition studies in the cell model. RESULTS AC inhibited HG-induced HBZY-1 cell proliferation and significantly improved various indicators of DN in rats, including reduced body weight, and elevated blood glucose, serum creatinine, blood urea nitrogen, and 24-h urine protein. Both in vitro and in vivo studies demonstrated that AC decreased inflammation and oxidative stress by reducing interleukin (IL)-6, IL-8, tumor necrosis factor-alpha, reactive oxygen species, and malondialdehyde levels while increasing superoxide dismutase activity. Additionally, AC suppressed the expression of fibrogenic markers such as collagen I, collagen IV, and fibronectin. AC activated NRF2 expression in the nucleus and increased HO-1 and NAD(P)H dehydrogenase (Quinone) 1 protein expression in renal tissues and HG-induced HBZY-1 cells. CONCLUSION AC improves DN by reducing inflammation, oxidative stress, and fibrosis through the activation of the NRF2/HO-1 signaling pathway. These findings not only highlight AC as a promising therapeutic candidate for DN but also underscore the potential of targeting the NRF2/HO-1 pathway in developing novel treatments for other chronic kidney diseases characterized by oxidative stress and inflammation.

The Effect of Nerolidol on Renal Dysfunction following Bilateral Ureteral Obstruction.

Background/Objectives: Obstructive uropathy is a common cause of renal impairment. Recently, there has been a burgeoning interest in exploring natural products as potential alternative remedies for many conditions due to their low toxicity, affordability and wide availability. Methods: We investigated the effect of nerolidol in a rat model of bilateral ureteral obstruction (BUO) injury. Nerolidol, dissolved in a vehicle, was administered orally as a single daily dose of 200 mg/kg to Wistar rats. Sham group (n = 12) underwent sham surgery, whereas the BUO (n = 12) and BUO/NR groups (n = 12) underwent reversible 24-h BUO and received the vehicle or nerolidol, respectively. The treatment started 9 days prior to the BUO/sham surgery and continued for 3 days after reversal. Renal functions were assessed before starting the treatment, just prior to the intervention and 3 days after BUO reversal. Results: Neither nerolidol nor the vehicle affected the basal renal functions. Nerolidol resulted in a significant attenuation in the BUO-induced alterations in renal functional parameters such as serum creatinine and urea, creatinine clearance and urinary albumin-creatinine ratio. Nerolidol also attenuated the changes in several markers associated with renal injury, inflammation, apoptosis and oxidative stress and mitigated the histological alterations. Conclusions: The findings of this study demonstrated the potent reno-protective effects of nerolidol in mitigating the adverse renal effects of bilateral ureteral obstruction. This is attributed to its anti-inflammatory, anti-fibrotic, anti-apoptotic and anti-oxidant properties. These effects were reflected in the partial recovery of renal functions and histological features. These findings may have potential therapeutic implications.

The Protective Effects of Methionine on Nickel-Induced Oxidative Stress via NF-κB Pathway in the Kidneys of Mice.

Nickel (Ni) is a human carcinogen that causes oxidative damage to many organs, and methionine has been studied to protect mammals from similar toxic effects by other heavy metals possibly through sulfur metabolism. This study aimed to investigate the protective effects of methionine on Ni-induced injuries to the kidneys. In this study, the mice were randomly divided into BC (normal diet), MD (methionine deficiency diet), MN (methionine plus nickel diet), and MDN (methionine deficiency plus nickel diet) treatment groups. Their renal function, histological changes, cell cycle, apoptosis, oxidative damage, and NF-κB inflammatory cytokines were detected after 21days by HE, immunohistochemistry, TUNEL staining, and biochemical and ELISA methods. The results showed that serum Cr, BUN, and the NAG content increased in MDN (P < 0.01), MN (P < 0.05), and MD (P < 0.05) group mice compared to BC group mice. Glomerulus atrophy and renal tubular atrophy were observed in the MDN, MN, and MD groups but less severe in MN group mice. The PCNA protein content was the highest in BC group mice followed by MD, MN, and MDN. The activities of antioxidant enzymes (SOD, CAT, GSH, GSH-Px, and GSH-ST) were lower significantly in MD, MN, and MDN group mice, and the oxidant products content (MDA, LPO, and ROS) in the BC group were higher than those in other groups with a similar trend. The contents of NF-κB, TNF-α, IFN-γ, IL-1a, and IL-6 in the BC group were found to increase significantly in MD, MN, and MDN groups. In conclusion, Ni-induced kidney injury was indicated by renal tissue and cell damage, increased kidney metabolism products release in the serum, and renal oxidative stress while methionine addition helped alleviate the injury. In addition, the NF-κB signal pathway was involved in the renal inflammatory reaction induced by Ni where methionine helped mitigate it.

6:2 chlorinated polyfluoroalkyl ether sulfonate (F–53B) induced nephrotoxicity associated with oxidative stress, inflammation and fibrosis in mice

6:2 Chlorinated polyfluoroalkyl ether sulfonate (trade name F–53B) is a substitute for perfluorooctane sulfonate (PFOS) used in the plating industry, and has been found in a range of environmental matrices and livings. There are numerous ways by which it is biotoxic to mammals. The kidneys are critical for maintaining homeostasis. However, little research has been conducted on how F–53B affects the kidneys. In this work, we investigated the renal toxicity of long-term oral F–53B treatment in C57BL/6J mice. Mice were allowed to drink F–53B freely at concentrations of 0, 0.057, 0.57, and 5.7 mg/L for 8 weeks. Renal oxidative stress, inflammation, and fibrosis were detected in mice exposed to F–53B, and the expression of related biochemical markers was significantly altered. Further investigations revealed that the TGF-β1/Smad3 and NF-κB signaling pathways may be associated with F–53B-induced renal fibrotic damage and inflammation. Overall, this study suggested that F–53B causes renal injury possibly via oxidative stress, activating the TGF-β1/Smad3 and NF-κB signaling pathways. This provides a foundation for further research into the harmful mechanism of F–53B in mammals.

Sorghum bicolor polyphenol-rich extract improves insulin sensitivity and protect against chronic stress exacerbated diabetic nephropathy through modulation of Nrf2/NF-κB

IntroductionSorghum bicolor leaf sheath is known for its rich phytoconstituents 3-in deoxyanthocyanidins with protective and health benefits in targeting oxidative stress, inflammation and apoptosis. This study aimed to investigate Sorghum bicolor polyphenol-rich extract (SBPE) and its combination with metformin on insulin resistance and diabetic nephropathy in high-fat/streptozotocin-induced diabetic rats exposed to chronic stress. MethodsAntidiabetic and nephroprotective effects of SBPE was investigated in male Wistar rats fed with high-fat diet and injected streptozotocin (35 mg/kg) intraperitoneally. Diabetic rats were exposed to chronic unpredictable mild stress and orally treated with SBPE (200 mg/kg), metformin (250 mg/kg) and SBPE+metformin for 28 days. Kidney function parameters, FBS, insulin, adiponectin, kidney injury marker (KIM-1), triglycerides were determined. Renal tissues inflammatory (TNF-α, IL-1β, IL-10), oxidative stress, apoptotic (caspase-3,-9) and transcriptional factors (Nrf2 and NF-κB) were determined as well as histology. ResultsSBPE significantly reduced FBS, triglycerides insulin and parameters for insulin resistance in diabetic rats exposed to stress. Dysregulated electrolytes, urea, creatinine, adiponectin and KIM-1 were significantly reversed in SBPE and SBPE+metformin groups. SBPE treatment significantly reduced MDA, nitrites, TNF-α, and IL-1β levels, while GSH, catalase, SOD, GST and IL-10 were increased in renal tissues. Increased apoptotic markers (caspase-3, caspase-9) and NF-κB, along with reduced Nrf2 levels, were significantly reversed by SBPE and SBPE+metformin. Distorted kidney histomorphoarchitecture was reversed in SBPE-treated groups ConclusionSorghum bicolor polyphenol-rich extract and its combination with metformin showed promising antidiabetic effects in stress-exacerbated diabetes in rats through improving insulin sensitivity and nephroprotective mechanisms.

An Oxidative Stress Study on Curcumin and NanoCurcumin against Aluminum Phosphide-induced Kidney Injury in Rats: The Role of SIRT1/FOXO3 Signaling Pathway in Nephrotoxicity.

In this study, we have investigated the aluminium phosphide (ALP) toxicity on Renal Function and oxidative stress in kidney tissue of male rats and the possible protective role of Curcumin and nanoCurcumin against ALP-induced nephrotoxicity. Thirty-six adult male rats were divided into 6 groups (n=6). ALP (2 mg/kg oral administration) and control groups received Curcumin and nanoCurcumin (oral administration 100 mg/kg) or without it. After seven days of treatment, kidney parameters, oxidative stress biomarkers, and expression level of sirtuins1 (SIRT1)/Forkhead box protein O1 (FoxO1) pathway genes were evaluated in kidney tissue. In addition, histopathological changes in the kidney tissues were assayed. In the ALP group, compared to the control group, lipid peroxidation levels, urea, and creatinine were increased, and total antioxidant capacity and thiol groups decreased significantly p < 0.05. In Curcumin and nanoCurcumin groups compared to the ALP group, lipid peroxidation and creatinine decreased significantly p < 0.05. Also, Curcumin and nanoCurcumin improved the tissue damage caused by ALP. NanoCurcumin modulated the effect of ALP on the gene expression levels in SIRT1/FoxO1. The present study showed that ALP intoxication in kidney tissue can induce oxidative damage. Moreover, Curcumin and nanocurcumin, as potential antioxidants, can be effective therapeutics in ALP-induced nephrotoxicity.

Effects of Yishentongluo Recipe on Nrf2 and HO-1 pathway activation leading to reduction of oxidative stress and kidney fibrosis in membranous nephropathy rat model

This study investigated Yishentongluo Recipe (YSTLF) effects on renal oxidative stress and fibrosis in membranous nephropathy (MN) rats. MN was induced by cationized bovine serum albumin injection. Rats were divided intocontrol, MN, YSTLF, and benazepril groups. After four weeks of treatment, urine protein levels (UTP), serum total cholesterol (TC), triglycerides (TG), total protein (TP), and albumin (ALB) were assessed. Kidney microstructure, IgG immune complex deposition, and protein expressions of superoxide dismutase (SOD), malondialdehyde (MDA), transforming growth factor β1 (TGF-β1), collagen I (Collagen-I), α-smooth muscle actin (α-SMA), nuclear factor E2-related factor (Nrf2), haem oxygenase 1 (HO-1), and NADPH oxidase 4 (NOX4) were evaluated. YSTLF and BNPL treatments reduced UTP, TC, TG, increased TP and ALB levels, downregulated TGF-β1, Collagen-I, and α-SMA, and upregulated Nrf2, HO-1, and NOX4. YSTLF partially reversed SOD reduction and MDA elevation, suggesting its efficacy in alleviating renal oxidative stress and fibrosis in MN rats via Nrf2/HO-1 signaling pathway activation.

Dang-Gui-Bu-Xue decoction against diabetic nephropathy via modulating the carbonyl compounds metabolic profile and AGEs/RAGE pathway

BackgroundDang-Gui-Bu-Xue decoction (DBD) is a traditional Chinese medicine prescription clinically employed for diabetic nephropathy (DN). However, the components and pharmacological mechanisms of DBD against DN remain incompletely understood. PurposeTo clarify the beneficial effect of DBD on DN and to explore its nephroprotective effect's probable mechanism and the main components. MethodsA diabetic mice model was established by feeding a high-fat diet (HFD) and intraperitoneal injections of streptozotocin (STZ, 40 mg‧kg-1). Subsequently, the mice were maintained on a HFD and administered with DBD. The benefits of DBD against DN were comprehensively assessed by monitoring energy and water intake, blood glucose and lipids, renal functions and pathological status. The UPLC-MS/MS was measured to detect chemical constituents in DBD and absorbed components in DBD-treated plasma under physiological and pathological states. Network pharmacology was employed to forecast the probable pathways of DBD intervention in DN, with subsequent validation of these predictions through testing biochemical parameters, anti-glycation and ELISA assays, immunofluorescence, immunohistochemistry, and western blotting. Then, a chemical derivatization method paired with UPLC-MS/MS analysis was performed to detect the carbonyl compounds in renal tissue. Finally, the main components of DBD against DN were screened by anti-glycation and MTT assays. ResultsDBD regulated energy and water intakes, glucose and lipid metabolism disorders, renal dysfunction, glomerular filtration rate, renal interstitial glycogen accumulation and fibrosis in HFD/STZ-induced DN mice. A total of 129 distinct chemical constituents in DBD were characterized, of which 28 were detected in the DBD-treated plasma under a pathological state. The network pharmacological results suggested AGEs/RAGE and its downstream pathway may be a potential pathway for DBD intervention in DN. Further experiments confirmed that DBD reduced renal oxidative stress by modulating the AGEs/RAGE pathway. Moreover, 21 differential carbonyl compounds were detected between normal and DN mice, and DBD significantly modulated 16. Ultimately, seven components were screened out in DBD, which may be the main components of DBD regulating carbonyl compounds metabolic profile and AGEs/RAGE pathway. ConclusionOur findings suggested for the first time that DBD could regulate the carbonyl compounds metabolic profile and AGEs/RAGE signaling pathway to ameliorate DN.

Gut microbiome and metabolites mediate the benefits of caloric restriction in mice after acute kidney injury

The role of gut microbiome in acute kidney injury (AKI) is increasing recognized. Caloric restriction (CR) has been shown to enhance the resistance to ischemia/reperfusion injury to the kidneys in rodents. Nonetheless, it is unknown whether intestinal microbiota mediated CR protection against ischemic/reperfusion-induced injury (IRI) in the kidneys. Herein, we showed that CR ameliorated IRI-elicited renal dysfunction, oxidative stress, apoptosis, and inflammation, along with enhanced intestinal barrier function. In addition, gut microbiota depletion blocked the favorable effects of CR in AKI mice. 16S rRNA and metabolomics analysis showed that CR enriched the gut commensal Parabacteroides goldsteinii (P. goldsteinii) and upregulated the level of serum metabolite dodecafluorpentan. Intestinal colonization of P. goldsteinii and oral administration of dodecafluorpentan showed the similar beneficial effects as CR in AKI mice. RNA sequencing and experimental data revealed that dodecafluorpentan protected against AKI-induced renal injury by antagonizing oxidative burst and NFκB-induced NLRP3 inflammasome activation. In addition, we screened and found that Hamaudol improved renal insufficiency by boosting the growth of P. goldsteinii. Our results shed light on the role of intestinal microbiota P. goldsteinii and serum metabolites dodecafluorpentan in CR benefits to AKI.

Preparation and biological evaluation of a glucose-responsive block copolymer nanoparticle with the ability to ameliorate diabetic kidney damage

In this study, a p(AAPBA-b-Daidzein) block copolymer was designed and synthesised using glucose-responsive 3-acrylamidophenylboronic acid (AAPBA) and esterified daidzein as structural units; this copolymer possessed anti-diabetic pharmacological activity. After confirming the chemical structure of the copolymer, nanoparticles of the copolymer were prepared using the water-in-oil method. The results of the in vitro experiments showed that nanoparticles swelled when the pH was >7 or when the glucose concentration exceeded 1.0 mg/mL. Particle size measurements showed that the size of the nanoparticles was kept in the range of 100–300 nm before and after the glucose response, which helped avoid their clearance by the liver and kidneys. As the nanoparticles swelled, insulin and esterified daidzein were continuously released. The nanoparticles subcutaneously injected into mice with streptozotocin-induced diabetes were able to quickly and continuously reduce the blood sugar levels; significantly improve renal pathological damage and reduce renal function damage, inflammatory factors and oxidative stress indicators. In summary, the p(AAPBA-b-Daidzein) glucose-responsive nanoparticles prepared in the current study possess good pH value and glucose sensitivity, can achieve a precise and controlled release of insulin and exert the pharmacological activity of esterified daidzein. Therefore, it shows potential clinical application value in the treatment of diabetes and its complications.

Follistatin lowers blood pressure and improves vascular structure and function in essential and secondary hypertension.

Hypertension is characterized by resistance artery remodeling driven by oxidative stress and fibrosis. We previously showed that an activin A antagonist, follistatin, inhibited renal oxidative stress and fibrosis in a model of hypertensive chronic kidney disease. Here, we investigate the effects of follistatin on blood pressure and vascular structure and function in models of essential and secondary hypertension. 5/6 nephrectomised mice, a model of secondary hypertension, were treated with either exogenous follistatin or with a follistatin miRNA inhibitor to increase endogenous follistatin for 9 weeks. Blood pressure in mice was measured by tail cuff. Spontaneously hypertensive rats, a model of essential hypertension, were treated with follistatin for 8 weeks. Wistar Kyoto (WKY) rats were used as the normotensive control. Blood pressure in rats was measured by radiotelemetry. Mouse superior mesenteric arteries and rat first branch mesenteric arteries were isolated for structural and functional analyses. In both models, follistatin significantly lowered blood pressure and improved vascular structure, decreasing medial thickness and collagen content. Follistatin also reduced agonist-induced maximum contraction and improved endothelium-dependent relaxation. Increased vessel oxidative stress was attenuated by follistatin in both models. In ex vivo WKY vessels, activin A increased oxidative stress, augmented constriction, and decreased endothelium-dependent relaxation. Inhibition of oxidative stress restored vessel relaxation. This study demonstrates that follistatin lowers blood pressure and improves vascular structure and function in models of essential and secondary hypertension. Effects were likely mediated through its inhibition of activin A and oxidative stress. These data suggest a potential therapeutic role for follistatin as a novel antihypertensive agent. Follistatin, through antagonization of activin A, inhibits oxidative stress and improves vascular structure and function in resistance arteries from models of essential and secondary HTN. FST decreases collagen content and vascular ROS. Functionally, FST improves endothelium-dependent relaxation and decreases maximal vasoconstriction. Improved resistance artery structure and function are correlated with a decrease in BP in both models.

Paricalcitol prevents renal tubular injury induced by ischemia-reperfusion: Role of oxidative stress, inflammation and AT1R

The vitamin D receptor (VDR) is associated with antioxidative and anti-inflammatory effects and modulation of the renin-angiotensin-aldosterone system. This study evaluated whether VDR agonist paricalcitol protects renal ischemia-reperfusion (IR) induced tubular injury in rats by evaluating: 1) ATP-dependent tubular Na+ transport; 2) renal redox signaling; 3) renal content of proinflammatory cytokines TNF-α and IL-6; and 4) renal content of renin and angiotensin II receptor type 1 (AT1R). Paricalcitol prevented IR-induced tubular injury, evidenced by the prevention of histopathological changes and renal fibrosis with preservation of the activity of ATP-dependent Na+ transporters in the renal cortex. Paricalcitol decreased renal oxidative stress by reducing NADPH oxidase activity and increasing catalase. Paricalcitol also decreased the renal content of TNF-α, IL-6, and AT1R. The NADPH oxidase inhibitor apocynin did not present additive protection to paricalcitol-induced effects. The protective effects of paricalcitol on tubular injury induced by renal IR may dependent on the modulation of redox and proinflammatory signaling and renal angiotensin II/AT1R signaling.

P099 EXERCISE TRAINING FURTHER ATTENUATES BLOOD PRESSURE VARIABILITY AND RENAL DAMAGE IN HYDROCHLOROTHIAZIDE TREATED-HYPERTENSIVE AND POSTMENOPAUSAL RATS

Background and Objective: Considering that blood pressure variability (BPV) has been associated with damage to target organs such as the kidney, this study aimed to investigate the effects of hydrochlorothiazide (HCTZ) combined with exercise training (CET) on BPV, as well as renal tissue morphology, function, inflammation, and oxidative stress. Methods: Female spontaneously hypertensive rats (SHR) were divided into 4 ovariectomized groups (n=5-6/group): sedentary (OS), sedentary + HCTZ (OSH), trained (OT), and trained + HCTZ (OTH). Both HCTZ (3 mg/kg) and CET (3 days/week) were administered for 8 weeks. Blood pressure was directly recorded for BPV analysis. Results: Renal function, morphology, inflammation and oxidative stress were assessed. The OSH, OT, and OTH groups had lower systolic BP (OSH: 189±13; OT: 179±5; OTH: 174±15 mmHg) compared to the OS group (208±15 mmHg). Only the combination of the drug with CET promoted a reduction in BPV variance. The HCTZ-treated groups showed lower plasma creatinine levels and increased creatinine clearance compared to the OS group. Treated groups showed a reduction in fields of 51–100% of interstitial tubule fibrosis when compared to the OS group; and the OTH group also showed reduction in fields in the range of 26–50% vs. other groups. The HCTZ-treated groups showed a reduction in protein oxidation. Renal catalase and IL10/TNF-alpha ratio were increased in the OTH group. Positive correlations were obtained between SBP variance and SBP (r=0.72), plasma creatinine (r=0.58), and levels of TNF-α (r=0.69), hydrogen peroxide (r=0.61), and protein oxidation (r=0.66) in renal tissue. Conclusions: Our results highlight the enhanced efficacy of the combination of HCTZ and CET compared to the use of either drug alone in the model studied. This combination effectively reduced BPV, resulting in beneficial changes in renal inflammatory and redox profiles, inducing morphological and functional benefits in hypertensive ovariectomized rats. Financial support: FAPESP (2022/04050-1), CNPq, CAPES-PROSUP, UNINOVE.

Breast Milk-Derived Stem Cells Diminished Cisplatin-Induced Acute Kidney Injury in Male Rats Via Modulating Renal Growth Factor Receptors, Autophagy, and Oxidative Stress

Breast Milk-Derived Stem Cells Diminished Cisplatin-Induced Acute Kidney Injury in Male Rats Via Modulating Renal Growth Factor Receptors, Autophagy, and Oxidative Stress

Salinomycin, a potent inhibitor of XOD and URAT1, ameliorates hyperuricemic nephropathy by activating NRF2, modulating the gut microbiota, and promoting SCFA production

Long-term hyperuricemia can induce kidney damage, clinically referred to as hyperuricemic nephropathy (HN), which is characterized by renal fibrosis, inflammation, and oxidative stress. However, currently used uric acid-lowering drugs are not capable of protecting the kidneys from damage. Therefore, uric acid-lowering drugs that can also protect the kidneys are urgently needed. In this study, we first discovered that salinomycin, an antibiotic, can regulate uric acid homeostasis and ameliorate kidney damage in mice with HN. Mechanistically, salinomycin inhibited serum and hepatic xanthine oxidase (XOD) activities and downregulated renal urate transporter 1 (URAT1) expression and transport activity, thus exerting uric acid-lowering effects in mice with HN. Furthermore, we found that salinomycin promoted p-NRF2 Ser40 expression, resulting in increased nuclear translocation of NRF2 and activation of NRF2. More importantly, salinomycin affected the gut microbiota and promoted the generation of short-chain fatty acids (SCFAs) in mice with HN. In conclusion, our results revealed that salinomycin maintains uric acid homeostasis and alleviates kidney injury in mice with HN by multiple mechanisms, suggesting that salinomycin might be a desirable candidate for HN treatment in the clinic.

Endoplasmic reticulum stress promotes oxidative stress, inflammation, and apoptosis: A novel mechanism of citrinin-induced renal injury and dysfunction

Citrinin (CTN) has been reported to induce renal failure and structural damage, but its nephrotoxic effects and mechanisms are not fully understood. Therefore, we established a model by orally administering CTN (0, 1.25, 5, or 20 mg/kg) to mice for 21 consecutive days. Histological and biochemical analyses revealed that CTN caused structural damage to renal tubules, increased inflammatory cell infiltration, and elevated levels of serum markers of renal function (creatinine, urea, and uric acid). Moreover, mRNA transcript levels of the inflammatory factors TNF-α, IL-1β, and IL-6 were increased, indicating the occurrence of an inflammatory response. Furthermore, exposure to CTN induced renal oxidative stress by decreasing antioxidant GSH levels, antioxidant enzyme (SOD, CAT) activities, and increasing oxidative products (ROS, MDA). In addition, CTN increased the expression of proteins associated with endoplasmic reticulum (ER)stress and apoptotic pathways. ER stress has been shown to be involved in regulating various models of kidney disease, but its role in CTN-induced renal injury has not been reported. We found that pretreatment with the ER stress inhibitor 4-PBA (240 mg/kg, ip) alleviated CTN-induced oxidative stress, NF-κB pathway mediated inflammatory response, and apoptosis. Interestingly, 4-PBA also partially alleviated renal structural damage and dysfunction. Thus, ER stress may be a novel target for the prevention and treatment of CTN-induced renal injury.

Effect of a Triterpenoid-Rich Olive Oil on Chronic Kidney Disease in an Experimental Model of Diabetes Mellitus.

The aim of this study was to assess the effect of triterpenoids on the development of diabetic nephropathy in an experimental model of diabetes mellitus. For this purpose, a destoned and dehydrated olive oil (DDOO) was used, comparing its effects to a destoned olive oil (DOO). DDOO had a higher triterpenoid content than DOO but an equal content of alcoholic polyphenols. Four study groups (n = 10 animals/group) were formed: healthy rats, diabetic control rats (DRs), and DRs treated orally with 0.5 mL/kg/day of DOO or DDOO for two months. DRs showed impaired renal function (proteinuria, increased serum creatinine, decreased renal creatinine clearance) and morphology (glomerular volume and glomerulosclerosis). These alterations correlated with increased systemic and renal tissue oxidative stress and decreased prostacyclin production. DDOO administration significantly reduced all variables of renal damage, as well as systemic and renal oxidative stress, to a greater extent than the effect produced by DOO. In conclusion, triterpenoid-rich olive oil may prevent kidney damage in experimental diabetes mellitus.