A missense mutation in acyl-CoA synthetase ACSL4 reveals essential residues for catalytic activity in ferroptosis.

Assessment of the novel platinum(IV) complexes effects on female rats' kidneys: Possible nephroprotection of resveratrol.

The kidneys are powerful chemical factories that function to keep the body stable. This research was carried out to determine the morphological alterations in the kidney tissues upon administration of aqueous and methanolic leaf extract of Gongronema latifolium orally. A total of 15 rats were grouped into five in this manner: Control as Group 1, low dose (280 mg/kg) of the aqueous extract was received by Group 2, Group 3 received a high dose (560 mg/kg) of the aqueous extract, Group 4 received a low dose (150 mg/kg) of the methanolic extract, and Group 5 received a high dose (300 mg/kg) of the methanolic extract of Gongronema latifolium leaf extract. The rats were kept to acclimatize for 2 weeks after which the extracts were given for 21 days. Blood specimens were obtained through the rats' medial canthus of its retro-orbital plexus into a plain tube for biochemical evaluation. The kidney tissues were harvested, fixed in 10% NBF, and processed using the automatic tissue processor to determine the histomorphological changes. Results showed a significant (p < 0.05) increase in the weights of rats when compared to the control after administration. The relative organ weight and biochemical parameters showed no significant differences. The histological samples revealed mild morphological changes in groups 2, 3 and 4 showing eosinophilic materials in the form of hyaline glomerulopathy with eosinophilic casts, which can be attributed to environmental factors. In conclusion, results obtained in the study have shown a positive effect of Gongronema latifolium leaf extract in the kidney tissues and in weight gain, proving that it maybe safe for consumption.

MicroRNA-Mediated Regulation of Hypoxic Kidney Adaptation in Naked Mole-rats (Heterocephalus glaber).

Impact of fluoride on antioxidant activity and mitochondrial homeostasis in fetal rat kidney.

Consumption of water from man-made reservoirs and groundwater contaminated with arsenic and antimony increases the risk of kidney damage. The aim of the study was to investigate the spectrum of disorders of the excretory function of the kidneys in rats exposed to subthreshold, threshold, and effective doses of antimony and arsenic ingested with drinking water. Material and methods . Male Wistar rats (n = 125) received water from a man-made reservoir contaminated with antimony and arsenic for 90 days. The excretory function of the kidneys was evaluated on days 40 and 90 using conventional methods. Results and discussion . The specific effects of the combined action of antimony and arsenic on kidney function were studied, depending on the levels and duration of exposure, and the dose-response relationships were quantified. The predicted changes in kidney function indicators obtained using approximating curves were almost identical to the empirical data. Conclusions . The combined contamination of man-made reservoirs and groundwater with arsenic and antimony, which have nephrotoxic effects, increases the risk of kidney damage in potentially exposed population groups.

Normothermic Machine Perfusion of Rat Kidneys for Transplantation

A proteomic analysis of rat liver and kidney was performed following exposure to morphine (10 mg/kg, 10 days) versus untreated controls. Our data revealed alterations in numerous protein expression. Differences were observed in pro- and antiapoptotic signaling, oxidative stress response, transport mechanisms, nucleic acid metabolism, and regulators of alternative splicing, among others. Liver tissue exhibited primarily adaptive changes, including upregulation of metabolic enzymes and subtle markers of oxidative stress. In contrast, the kidneys displayed a broader spectrum of proteomic alterations, affecting a wider array of functional pathways, suggesting that this organ may be more susceptible to morphine-induced toxicity or that of its metabolites. We employed also MALDI-MSI to examine lipidomic alterations: while no significant changes were detected in liver tissue, important lipidomic alterations were observed in the kidneys, further supporting their increased vulnerability to morphine exposure. Our results should be regarded as preliminary; however, they highlight a promising direction for identifying early stage protein markers of toxicity using proteomic approaches. Monitoring such markers could prove valuable in multidrug therapies, particularly for patients with a history of hepatic or renal impairment, contributing to the development of safer therapeutic strategies. Data are available via ProteomeXchange under the identifiers: PXD067999 (DDA) and PXD068084 (DIA).

The downregulation of Klotho in renal injury predicts the progression of chronic kidney disease (CKD). Klotho acts as an antagonist of the Wnt/β-catenin pathway, which is involved in the pathogenesis of proteinuria, glomerulosclerosis and tubulointerstitial fibrosis. We investigated whether losartan (L, angiotensin II type-1 receptor blocker) alone or combined with synthetic (tempol, T) or natural antioxidants (olive leaf extract, O) could alter Klotho/Wnt4/β-catenin signaling, thus reducing fibrosis and slowing the progression of focal segmental glomerulosclerosis (FSGS) in spontaneously hypertensive rats (SHR). The rats were divided into five groups. The control rats received a vehicle. The other groups received adriamycin (2 mg/kg, i.v., twice in a 3-week interval) for FSGS induction. Treatments with L, L+T and L+O (10, 10 + 100 and 10 + 80 mg/kg/day, respectively) were administered by gavage during six weeks. In the kidneys of model rats, Klotho and Wnt4 were downregulated, whereas β-catenin and fibronectin levels were increased compared with the control group. L+T did not alter Klotho, Wnt4 or fibronectin levels, while it further increased β-catenin. In contrast, L+O improved Klotho, and reduced β-catenin and fibronectin levels, although it increased PAI-1. The L+O combination reduced proteinuria more efficiently than L and decreased renal injury close to control levels. Although these findings indicate that combined treatment of losartan and olive leaf extract is promising in slowing the progression of the experimental FSGS, further clinical studies are needed to confirm its favorable outcomes and safety in CKD patients.

To monitor the changes in oxygenation levels of rat kidneys under step oxygen stimulation by high temporal resolution dynamic T2* weighted planar echo imaging (T2*W-EPI). Step oxygen stimulation was applied to SD rats (n=10) in the sequence of 2 min of hyperoxia (100% O2) -10 min of hypoxia (10% O2) -10 min of hyperoxia (100% O2). Dynamic MRI data of the kidneys of multi-echo gradient echo (mGRE) sequence and gradient echo-planar imaging (EPI) sequence were continuously acquired on a 9.4T small animal magnetic resonance scanner. The time resolution of the two sequences were 9 s and 1 s, respectively. A second-order step response model was established for the dynamic time series curves of different regions of interest (ROIs) in rat kidneys, and the parameters of the step response model were obtained, including time delay ∆t, natural frequency ωn, damping constant D and oscillation period T. The performance of two MRI imaging methods with different temporal resolution in response to the step oxygen stimulation in the kidneys was compared. Compared with the control experiment results of mGRE, the dynamic T2*W-EPI technology proposed in this study increased the temporal resolution of monitoring renal step oxygen stimulation by 8 folds and improved the goodness of fit of the step response model. The model showed a shorter time delay ∆t (shortened by 29.4%, 42.6%, 56.4%, and 47.4%, respectively, in the CO, OSOM, ISOM and IM), a larger natural frequency ωn (increased by 21.1%, 28.6%, 52.2%, and 61.9%, respectively), and oscillation of each ROI (damping constant D<1) under the step oxygen stimulation. In a step oxygen stimulation model of rat kidneys, the high temporal resolution dynamic T2*W-EPI technique proposed in this study is capable of real-time monitoring of the changes in renal oxygenation levels for detection of abnormal renal conditions.

Rat kidney tissue slices are expected to be useful for an in vitro evaluation of drug-induced kidney injury (DIKI). We previously established a primary culture of rat kidney tissue slices using gas-permeable plates. However, polydimethylsiloxane (PDMS) exhibits a significant adsorption of lipophilic drugs, leading to limitations in DIKI evaluation. The aim of the present study was to evaluate a gas-permeable InnoCell™ non-treated plate made of polyolefin with low adsorption of lipophilic compounds for the primary culture of rat kidney tissue slices as an in vitro DIKI evaluation system. Drug concentrations in the medium were measured 24 h after the addition of 9 drugs to PDMS plates and InnoCell™ non-treated plates. Intra-tissue ATP levels and histopathology of rat kidney tissue slices were examined on Day 3 of culture. As a result, the InnoCell™ non-treated plates exhibited lower adsorption rates for sunitinib, cyclosporine A, and alectinib than the PDMS plates. Intra-tissue ATP levels were maintained, and immunohistochemical staining of megalin and aquaporin 1 was observed for up to 3 d. Furthermore, exposure to nephrotoxic lipophilic drugs reduced the ATP content in slices compared to that in non-treated slices. These results suggest that the primary culture of rat kidney tissue slices using InnoCell™ non-treated plates is useful for the DIKI evaluation of lipophilic drugs compared with conventional PDMS plates.

Congestive heart failure (CHF) is characterized by the activation of neurohumoral drive concomitant with avid fluid retention. Renal denervation alleviates this fluid retention. SGLT2 (sodium-glucose cotransporter 2) inhibitors have shown remarkable improvement in patients with cardiovascular diseases. We have recently demonstrated a relationship between enhanced renal sympathetic nerve activity and SGLT2 expression as well as function during CHF; however, the precise molecular mechanisms involved in the expression and translocation of SGLT2 and associated scaffolding proteins to the luminal membrane remain to be examined. CHF was induced by coronary artery ligation followed by bilateral renal denervation 4 weeks later, in rats. Western blot analysis and immunohistochemistry were performed to evaluate changes in the expression of SGLT2, MAP17 (membrane-associated protein 17), PDZK1 (PDZ domain containing 1), and activation of ERK (extracellular signal-regulated kinase)/NF-KB (nuclear factor κB) in renal cortex. Human adult proximal tubular cells were used to determine the direct effect of norepinephrine on the expression of SGLT2-MAP17-PDZK1 and activation of the ERK/NF-KB pathway. Rats with CHF exhibited significantly enhanced expression of SGLT2, MAP17, and PDZK1 with a concomitant significant activation of ERK and NF-KB in the renal cortex. In rats with CHF, renal denervation mitigated enhanced expression of SGLT2-MAP17-PDZK1 as well as activation of ERK and NF-KB. Direct action of norepinephrine on human adult proximal tubular cells cells triggered enhanced expression of SGLT2-MAP17-PDZK1 by the activation of the ERK/NF-KB pathway. Enhanced basal renal sympathetic nerve activity in CHF activates the ERK/NF-KB pathway, which in turn facilitates the enhanced expression and translocation of the SGLT2-MAP17-PDZK1 scaffolding protein complex to the luminal membrane, augmenting sodium reabsorption in CHF.

Introduction. Computed X-ray microtomography (micro-CT) enables getting the three-dimensional images of microscopic structures without damaging them, which makes this method widely implemented in biomedicine. Regarding the application of micro-CT in veterinary medicine, its potential in assessing morphological changes in internal organs of animals with pathologies has not yet been used at full scale. For example, there are no enough data on the capacity of microtomography in studying pathological processes in kidneys of animals. The aim of the present study is to assess the pathological changes in the density and morphology of kidney tissue in laboratory rats with hyperlipidemia using micro-CT. Materials and Methods. The experiment was conducted at DSTU from 2021 to 2024 and involved 40 male Wistar rats divided into 5 groups: 4 experimental and 1 control. During the experiment, the experimental groups were fed a hyperlipidemic diet; the control group received only standard feed-stuff. Kidneys were taken from decapitated animals on 30 th , 120 th , 150 th , and 180 th day, and samples were prepared for scanning with a Zeiss Xradia Versa 520 micro-CT scanner at 80 kV and voxel size of 20 μm. The efficiency of micro-CT was assessed by the quality of 3D reconstruction and detected changes in kidney tissue density and morphology at different stages of hyperlipidemia. Results. Microtomograms of kidneys of rats in the experiment allowed for detailed visualization of the organ’s morphology, including renal cortex and medulla, as well as vasculature. Quantitative data on changes in tissue density were obtained, and differences in kidney structure were distinguished between the normal (in control group) and pathological conditions (in experimental groups with various degrees of hyperlipidemia). Discussion and Conclusion. Micro-CT method has demonstrated high accuracy and informative value in analysing kidney tissue condition in rats and proved its efficiency in early diagnostics of pathological changes in these internal organs, as well as in dynamic monitoring of disease. Among the constraints of this method, the following aspects can be noted: the high cost of equipment, low sensitivity to soft tissues in the absence of contrast-enhancement, and the need for specialized skills to interpret the images.

While low-carbohydrate/high-protein diets are common for rapid weight loss, their controversial side effects warrant investigation. This study aimed to examine age- and duration-dependent effects of high-protein diets on the liver and kidneys of adult (6 months) and elderly (18 months) rats. Thirty-two male Wistar albino rats were divided into four groups: Adult Standard, Adult High-Protein, Elderly Standard, and Elderly High-Protein. After one month, we collected kidney and liver samples for histological analysis and biochemical assessment of MDA and GSH levels. RESULTS: High-protein diets severely affected the kidneys of both adult and elderly rats. The livers also exhibited moderate degenerative changes. We found a significant increase in MDA levels, indicating lipid peroxidation. Additionally, hepatic and renal GSH levels significantly increased in elderly rats on a high-protein diet, suggesting a metabolic response to oxidative stress. CONCLUSION: Our findings suggest that high-protein diets should be applied very cautiously, especially in elderly individuals and those with existing kidney disorders.

BackgroundPreviously we reported on the therapeutic monoclonal anti-human C2 antibody empasiprubart that inhibits activation of the classical and lectin pathways of complement. Preclinical studies with this antibody are hampered by its low affinity for C2 of animal species other than primates.Methods and resultsWe developed a high affinity, Ca2+-dependent anti-rat C2 antibody using the sequences and structural data of empasiprubart. Pharmacokinetics and pharmacodynamics of the resulting antibody in Sprague Dawley rats were assessed and used for an intervention study in a rat model of delayed graft function following kidney transplantation. The anti-rat C2 antibody improved kidney function and health in the rats within the first 2 weeks post-transplantation.ConclusionOur study shows the successful development of an analogue of empasiprubart that can be used in preclinical in vivo disease models and highlights the potential of C2-blocking as a therapeutic strategy for preventing delayed graft function following kidney transplantation.

Acetaminophen (APAP) overdose is a major cause of acute liver failure and can be fatal, often without early symptoms. Protein deficiency, arising from illness or inadequate diet, impairs growth, immunity, and tissue repair. Both conditions can harm the kidneys, yet the impact of energy imbalance on renal physiology remains unclear. In this study, APAP toxicity and a low-protein diet induced behavioral suppression and tissue damage, as evidenced by reduced whole-body, liver, and kidney weights in rats. In kidney mitochondria of rats exposed to only toxic APAP doses, ATP levels declined sharply while ADP and AMP increased. AMP deaminase and ATPases' activities rose about twofold and 1.5-fold, respectively, whereas cytosolic 5'-nucleotidase activity fell nearly threefold, suggesting compensatory responses to disrupted energy balance. The strongest reductions in ATP and the greatest increases in AMP and ATPase activity occurred in APAP-intoxicated rats fed a low-protein diet. This combination also intensified lipid peroxidation and oxidative protein damage, evidenced by elevated TBARS, reduced protein SH-groups, and increased protein carbonyls. Overall, APAP intoxication with protein deficiency disrupts renal energy metabolism, leading to mitochondrial dysfunction and structural kidney injury. Nutritional status therefore critically influences drug-induced nephrotoxicity, and antioxidant strategies may help prevent damage under metabolic stress.

Evaluating the activity of indoleamine 2,3-dioxygenase (IDO), the rate-limiting enzyme in tryptophan (Trp) metabolism, is important because IDO is involved in immune tolerance and drives the production of Trp metabolites implicated in psychiatric disorders and cancer. This study aimed to design and develop a novel fluorescent l-Trp derivative to fluorometrically monitor Trp-catabolizing enzyme activity via IDO. To evaluate IDO activity in vivo, 7-N,N-dimethylamino-2,1,3-benzoxadiazole (DBD), a fluorophore, was covalently bound at the 5-position of the indole ring in Trp to produce 5-DBD-l-Trp. An in vivo microdialysis (MD) study was conducted using the kidneys of Sprague-Dawley rats. Specifically, 5.0 μM 5-DBD-l-Trp in phosphate-buffered Ringer's solution was infused into the rats, and the MD sample was analyzed via high-performance liquid chromatography with fluorescence detection. In the MD sample, two fluorescence peaks other than 5-DBD-l-Trp were observed during the 5-DBD-l-Trp infusion, and the main metabolite peak was proposed to be 5-DBD-kynurenine, verified by liquid chromatography-tandem mass spectrometry. The intensity of the fluorescent peak was significantly attenuated by co-infusion with an IDO inhibitor, 1-methyl-d-Trp. These results suggest that 5-DBD-l-Trp may be metabolized by renal IDO and can be used to evaluate IDO activity in vivo.

Our research team developed AB-38b, a biphenyl diester derivative containing α,β-unsaturated carbonyl groups, inspired by investigations into the pharmacological prevention and pathophysiology of diabetic kidney disease (DKD). We have completed the synthesis and pharmacodynamic evaluation of AB-38b in preclinical DKD studies. For pharmacokinetic analysis, we established a high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method for quantifying AB-38b in rat plasma, as well as in liver and kidney tissues. Sample preparation involved protein precipitation using methanol, with tolvaptan employed as the internal standard (IS). Chromatographic separation was achieved on a Shim-pack VP-ODS C18 column (2.0 × 150 mm, 5 µm), with mobile phase A (5 mM ammonium acetate) and mobile phase B (methanol) under gradient elution at a flow rate of 0.2 mL min-1. AB-38b and the IS were detected and quantified using positive electrospray ionization in multiple reaction monitoring (MRM) mode at transitions of m/z 705.30 → 618.20 for AB-38b and m/z 449.30 → 252.20 for the IS. The method demonstrated excellent linearity, stability, accuracy, precision, recovery, and a non-significant matrix effect within the validated range. A one-compartment model with rapid absorption and distribution, quicker elimination, and clear tissue distribution was demonstrated by the mean blood concentration-time curve of AB-38b in rat plasma. The liver tissue contained high levels of AB-38b, with no evidence of tissue accumulation observed. These findings offer a reference for further research into the pharmacological mechanisms and potential therapeutic applications of AB-38b in metabolically related diseases, especially DKD.

Butterfly pea flowers (BPF) are widely used in Indonesia as a natural food and beverage colorants. BPF is also traditionally used to relieve diseases such as diabetes and cardiovascular diseases. However, few research has been conducted on the potential toxic effects of BPF infusion. Therefore, further research is necessary to evaluate its safe consumption dosage. The objective of this study was to investigate acute and subchronic toxicity of BPF infusion on histological structure of the kidney and liver in male albino rat. Acute toxicity treatment, BPF infusion was orally administered at the doses of 2500 and 5000 mg kg-1 BW for 14 days. For the subchronic toxicity treatment, BPF infusion was orally administered at the doses of 250, 500, and 1000 mg kg-1 BW. Histological preparations were performed using the paraffin method, followed by hematoxylin-eosin (HE) staining. The histological structures of the livers and kidney were evaluated using an ordinal scoring method. Data were analyzed using the Mann-Whitney test for acute treatments and the Kruskal-Wallis test for subchronic treatments (p ≤ 0.05). The results indicated very mild liver damage in the acute treatment groups, characterized by cellular degeneration. In the subchronic treatment groups, very mild damage was observed, including cellular degeneration and vacuolization. Additionally, very mild kidney damage, such as leukocyte infiltration and tubular hemorrhage, was detected in both acute and subchronic treatment groups. These findings suggest that BPF infusion is relatively safe for consumption, provided it is not consumed over an extended period.

The anti-aging gene/protein Klotho (Kl), most present in kidneys, has been well studied in mice (mKl), but not in rats (rKl). This study investigated the renal rKl expression in male and female rats. Sex-related measurement of rKl-controlled electrolytes was performed in plasma/urine samples, as were tests on species differences in renal Kl expression (rats vs. mice). rKl mRNA/protein expression was studied by qRT-PCR/Western-blotting in renal total RNA/cell membranes and its localization by immunofluorescence microscopy. Urine/plasma ions (phosphate/total calcium) and macroelements (phosphorus/calcium) were measured biochemically and by ICP-MS, respectively. In rat kidneys, the rKl mRNA/protein was detected in the cortex, outer and inner stripe but not in the papilla, and was immunolocalized in the basolateral membrane of proximal tubules in the cortex and outer stripe, but not in the intercalating cells of the cortical distal tubules, whereas mKl was observed in the mouse kidney cortex but not the outer stripe. Female-dominant expression of renal rKl, affected by androgen's inhibitory effect, may have contributed to the sex-related level of urine electrolytes, particularly phosphates. Renal mKl expression was male-dominant. Sex- and species-related differences in renal Kl expression may be relevant for the selection of the sex and/or the model organism in studies addressing aging/mineral homeostasis.