Search Results (543)

Acute kidney injury (AKI) is a serious clinical condition that is linked to markedly higher rates of morbidity and mortality in cirrhosis patients. Its diagnosis is challenging due to overlapping clinical and laboratory features among causes such as hepatorenal syndrome (HRS), acute tubular injury (ATI), and prerenal hypovolemia. In order to address the distinct pathophysiology and clinical context of cirrhosis, the definitions and classification of AKI have changed over time, moving from RIFLE and AKIN to KDIGO and ICA-AKI. Because cirrhosis patients have altered muscle mass and fluid retention, traditional markers like serum creatinine (sCr) and urine output have significant limitations. Neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), interleukin-18 (IL-18), and cystatin C (CysC) are some of the new biomarkers that have shown promise in early AKI detection and in differentiating structural from functional kidney injury. NGAL and KIM-1 are sensitive indicators of tubular damage with potential prognostic implications. IL-18 reflects inflammatory injury, and CysC offers a more reliable measure of glomerular filtration. Incorporating these markers may improve early diagnosis, risk stratification, and treatment decisions, representing a key direction for future research in managing AKI in cirrhosis. Full article

Background: Accumulating evidence indicates that SARS-CoV-2 infection results in long-term multiorgan complications, with the kidney being a primary target. This study aimed to characterize the long-term transcriptomic changes in the kidney following coronavirus infection using a murine model of MHV-1-induced SARS-like illness and to evaluate the therapeutic efficacy of SPIKENET (SPK). Methods: A/J mice were infected with MHV-1. Renal tissues were collected and subjected to immunofluorescence analysis and Next Generation RNA Sequencing to identify differentially expressed genes associated with acute and chronic infection. Bioinformatic analyses, including PCA, volcano plots, and GO/KEGG pathway enrichment, were performed. A separate cohort received SPK treatment, and comparative transcriptomic profiling was conducted. Gene expression profile was further confirmed using real-time PCR. Results: Acute infection showed the upregulation of genes involved in inflammation and fibrosis. Long-term MHV-1 infection led to the sustained upregulation of genes involved in muscle regeneration, cytoskeletal remodeling, and fibrotic responses. Notably, both expression and variability of SLC22 and SLC22A8, key proximal tubule transporters, were reduced, suggesting a loss of segment-specific identity. Further, SLC12A1, a critical regulator of sodium reabsorption and blood pressure, was downregulated and is associated with the onset of polyuria and hydronephrosis. SLC transporters exhibited expression patterns consistent with tubular dysfunction and inflammation. These findings suggest aberrant activation of myogenic pathways and structural proteins in renal tissues, consistent with a pro-fibrotic phenotype. In contrast, SPK treatment reversed the expression of most genes, thereby restoring the gene profiles to those observed in control mice. Conclusions: MHV-1-induced long COVID is associated with persistent transcriptional reprogramming in the kidney, indicative of chronic inflammation, cytoskeletal dysregulation, and fibrogenesis. SPK demonstrates robust therapeutic potential by normalizing these molecular signatures and preventing long-term renal damage. These findings underscore the relevance of the MHV-1 model and support further investigation of SPK as a candidate therapy for COVID-19-associated renal sequelae. Full article

Chronic kidney disease (CKD) has now reached epidemic proportions in many parts of the world, primarily due to the high incidence of diabetes and hypertension. By 2040, CKD is predicted to be the fifth-leading cause of years of life lost. Developing strategies to prevent CKD and to reduce its progression to kidney failure is thus of great public health significance. Hypertension is known to be both a cause and a consequence of kidney damage and an eminently modifiable risk factor. An increased risk of hypertension, especially among women, has been linked to chronic exposure to the ubiquitous food contaminant cadmium (Cd). The mechanism is unclear but is likely to involve its action on the proximal tubular cells (PTCs) of the kidney, where Cd accumulates. Here, it leads to chronic tubular injury and a sustained drop in the estimated glomerular filtration rate (eGFR), a common sequela of ischemic acute tubular necrosis and acute and chronic tubulointerstitial inflammation, all of which hinder glomerular filtration. The present review discusses exposure levels of Cd that have been associated with an increased risk of hypertension, albuminuria, and eGFR ≤ 60 mL/min/1.73 m² (low eGFR) in environmentally exposed people. It highlights the potential role of 20-hydroxyeicosatetraenoic acid (20-HETE), the second messenger produced in the kidneys, as the contributing factor to gender-differentiated effects of Cd-induced hypertension. Use of GFR loss and albumin excretion in toxicological risk calculation, and derivation of Cd exposure limits, instead of β₂-microglobulin (β₂M) excretion at a rate of 300 µg/g creatinine, are recommended. Full article

Background and Objectives: Coronavirus Disease 2019 (COVID-19) may cause extensive multi-organ pathology, particularly in the lungs, heart, kidneys, and liver. While hypercoagulability—often signaled by elevated D-dimer—has been thoroughly investigated, the concurrent pathological findings across organs and their interrelation with distinct D-dimer levels remain incompletely characterized. This study aimed to evaluate the pathological changes observed in autopsied or deceased COVID-19 patients, focusing on the prevalence of organ-specific lesions, and to perform subgroup analyses based on three D-dimer categories. Methods: We conducted a retrospective review of 69 COVID-19 patients from a Romanian-language dataset, translating all clinical and pathological descriptions into English. Pathological findings (pulmonary microthrombi, bronchopneumonia, myocardial fibrosis, hepatic steatosis, and renal tubular necrosis) were cataloged. Patients were grouped into three categories by admission D-dimer: <500 ng/mL, 500–2000 ng/mL, and ≥2000 ng/mL. Laboratory parameters (C-reactive protein, fibrinogen, and erythrocyte sedimentation rate) and clinical outcomes (intensive care unit [ICU] admission, mechanical ventilation, and mortality) were also recorded. Intergroup comparisons were performed with chi-square tests for categorical data and one-way ANOVA or the Kruskal–Wallis test for continuous data. Results: Marked organ pathology was significantly more frequent in the highest D-dimer group (≥2000 ng/mL). Pulmonary microthrombi and bronchopneumonia increased stepwise across ascending D-dimer strata (p < 0.05). Myocardial and renal lesions similarly showed higher prevalence in patients with elevated D-dimer. Correlation analysis revealed that severe lung and heart pathologies were strongly associated with high inflammatory markers and a greater risk of ICU admission and mortality. Conclusions: Our findings underscore that COVID-19-related organ damage is magnified in patients with significantly elevated D-dimer. By integrating pathology reports with clinical and laboratory data, we highlight the prognostic role of hypercoagulability and systemic inflammation in the pathogenesis of multi-organ complications. Stratifying patients by D-dimer may inform more tailored management strategies, particularly in those at highest risk of severe pathology and adverse clinical outcomes. Full article

The efficient synthetic routes and evaluates cytotoxic profiles of denitroaristolochic acids II–V (DAA-II–V) were demonstrated in this study. Based on retrosynthetic analysis, a modular synthetic strategy was developed through Suzuki–Miyaura coupling, Wittig reaction, and bismuth triflate-catalyzed intramolecular Friedel–Crafts cyclization to efficiently construct the phenanthrene core. Process optimization significantly improved yields: aryl bromide intermediate A reached 50.8% yield via bromination refinement, while arylboronic ester intermediate B overcame selectivity limitations. Combining Darzens condensation with Wittig reaction enhanced throughput, achieving 88.4% yield in the key cyclization. Structures were confirmed by NMR and mass spectra. CCK-8 cytotoxicity assays in human renal proximal tubular epithelial cells revealed distinct toxicological profiles: DAA-III and DAA-IV exhibited IC₅₀ values of 371 μM and 515 μM, respectively, significantly higher than the nitro-containing prototype AA-I (270 μM), indicating that the absence of nitro group attenuates but does not eliminate toxicity, potentially via altered metabolic activation. DAA-II and DAA-V showed no detectable cytotoxicity within assay limits, suggesting reduced toxicological impact. Structure–activity analysis exhibited that the nitro group is not essential for cytotoxicity, with methoxy substituents exerting limited influence on potency. This challenges the conventional DNA adduct-dependent toxicity paradigm, implying alternative mechanisms like oxidative stress or mitochondrial dysfunction may mediate damage in denitro derivatives. These systematic findings provide new perspectives for AA analog research and a foundation for the rational use and safety assessment of Aristolochiaceae plants. Full article

Hypertension and diabetes mellitus are key contributors to kidney damage, with the renal tubule playing a central role in the progression of kidney disease. MicroRNAs have important regulatory roles in renal injury and are among the most abundant cargos within extracellular vesicles (EVs), emerging as novel kidney disease biomarkers and therapeutic tools. Previously, we identified miR-200a-3p and its target SIRT1 as having a potential role in kidney injury. We aimed to evaluate miR-200a-3p levels in EVs from patient’s urine and delve into its function in causing tubular injury. We quantified miR-200a-3p urinary EV levels in hypertensive patients with and without diabetes (n = 69), 42 of which were with increased urinary albumin excretion (UAE). We analysed miR-200a-3p levels in EVs and cellular pellets, as well as their targets at mRNA and protein levels in renal tubule cells (RPTECs) subjected to high glucose and Angiotensin II treatments, and observed their influence on apoptosis, RPTEC markers and tubular injury markers. We conducted microRNA mimic and inhibitor transfections in treated RPTECs. Our findings revealed elevated miR-200a-3p levels in increased UAE patient urinary EVs, effectively discriminating UAE (AUC of 0.75, p = 0.003). In vitro, miR-200a-3p and renal injury markers increased, while RPTEC markers, SIRT1, and apoptosis decreased under treatments. Experiments using miR-200a-3p mimics and inhibitors revealed a significant impact on SIRT1 and decrease in tubular damage through miR-200a-3p inhibition. Increased levels of miR-200a-3p emerge as a potential disease marker, and its inhibition provides a therapeutic target aimed at reducing renal tubular damage linked to hypertension and diabetes. Full article

Background: Ischemia–reperfusion injury (IRI) is a key contributor to graft dysfunction in kidney transplantation. Cell-free mitochondrial DNA (mtDNA) is increasingly recognized as a damage-associated molecular pattern (DAMP) and biomarker in IRI, but its prognostic role in living donor kidney transplantation (LDKT) remains unclear. Methods: This post hoc analysis of the VAPOR-1 study evaluated urinary mtDNA (UmtDNA) in 57 LDKT recipients. MtDNA levels (ND1, ND6, and D-loop) were measured at five early timepoints post-transplantation using qPCR. Associations between early UmtDNA and long-term graft function, defined by estimated glomerular filtration rate (eGFR) at 1, 12, and 24 months, were analyzed. Results: Higher UmtDNA levels in the first urine after reperfusion were significantly associated with improved eGFR at 12 months and a positive change in eGFR between month 1 and 24. These associations were not attributable to urine creatinine levels or mitochondrial copy number. Conclusions: In this LDKT cohort, elevated early UmtDNA may reflect a well-functioning graft capable of clearing systemic mtDNA rather than ongoing tubular injury. These findings suggest that the biological interpretation of mtDNA as a biomarker is context-dependent and call for careful reconsideration of its role in early transplant monitoring. Full article

Background/Objectives: Chronic kidney disease (CKD) is twice as prevalent in individuals with obesity-associated non-alcoholic fatty liver disease (Ob-NAFLD), highlighting the need to determine the link and mechanisms of kidney injury as well as explore therapies. Metformin, a first-line treatment for type 2 diabetes, shows promise in managing NAFLD, but its renal benefits in Ob-NAFLD remain unclear. This study investigates the impact of Ob-NAFLD on kidney injury and assesses the potential protective effects of metformin. Methods: Five-week-old female Zucker rats (obese fa/fa and lean Fa/Fa) were fed an AIN-93G diet for 8 weeks to induce Ob-NAFLD, then fed the diet with Metformin for 10 weeks. Kidneys were collected for histopathological and biochemical analyses. Results: Histopathological studies showed increased tubular injury, mesangial matrix expansion, and fibrosis in kidneys with Ob-NAFLD compared to lean control (LC) rats. Immunohistochemistry further revealed an elevated macrophage and neutrophil infiltration and increased levels of nitrotyrosine and p22phox in Ob-NAFLD kidneys. Furthermore, Ob-NAFLD rat kidneys showed upregulation of TNF-α and CCL2 genes and increased levels of caspase-3 (total and cleaved). Interestingly, metformin treatment significantly decreased TNF-α mRNA and blunted nitrotyrosine levels, and modestly reduced immune cell infiltration in Ob-NAFLD. Conclusions: These findings indicate that Ob-NAFLD promotes CKD as evidenced by tubular injury, oxidative stress, inflammation, and fibrosis. While short-term metformin treatment showed anti-oxidative and anti-inflammatory effects in Ob-NAFLD, its impact on structural kidney damage was limited, highlighting the need for longer treatment or alternative therapeutics such as oxidant scavengers and anti-inflammatory drugs to effectively mitigate renal pathologies. Full article

Cisplatin (Cis) is a widely used chemotherapy drug, but its nephrotoxicity limits its clinical application. Acute kidney injury (AKI) is a common complication, restricting long-term use. This study investigates the mechanisms of cisplatin-induced AKI and explores potential therapeutic targets. C57BL/6J mice were intraperitoneally injected with 20 mg/kg cisplatin to establish an AKI model. Serum creatinine, urea nitrogen, and tubular injury biomarkers (NGAL, KIM-1) progressively increased, indicating kidney dysfunction. Mitochondrial ATP levels significantly decreased, along with reduced mitochondrial fission and fusion, suggesting mitochondrial dysfunction. Increased oxidases and reduced antioxidants indicated redox imbalance, and metabolic reprogramming was observed, with lipid deposition, impaired fatty acid oxidation (FAO), and enhanced glycolysis in proximal tubular epithelial cells (PTECs). Nuclear factor erythroid 2-related factor 2 (NRF2) is a key transcriptional regulator of redox homeostasis and mitochondrial function. We found NRF2 levels increased early in AKI, followed by a decrease in vivo and in vitro, suggesting activation in the stress response. Nfe2l2 knockout mice showed aggravated kidney injury, characterized by worsened kidney function and histopathological damage. Mechanistically, Nfe2l2 knockout resulted in redox imbalance, reduced ATP synthesis, mitochondrial dysfunction and metabolic dysregulation. Furthermore, we activated NRF2 using dimethyl fumarate (DMF), observing a reduction in kidney damage and lipid deposition in mice. In conclusion, activating NRF2-dependent antioxidant pathways plays a crucial role in protecting against cisplatin-induced AKI. NRF2 may serve as a potential target for developing therapeutic strategies to prevent cisplatin nephrotoxicity. Full article

Oxidative stress plays a crucial role in disease pathogenesis. While reactive oxygen species (ROS) directly cause cellular injury, emerging evidence suggests oxidatively modified proteins like albumin may also contribute significantly to tissue damage. Although oxidized albumin (ox-Alb) is linked to renal pathology, the direct effects and mechanisms of ox-Alb on renal cell injury remain unclear. This study was created to address these questions. In mouse models of renal injury initiated by vitamin C/copper or ischemia/reperfusion, levels of serum ox-Alb were significantly elevated. The treatment of albumin with copper/vitamin C increased Alb carbonylation and reduced the number of sulfhydryl groups, causing Alb oxidation. In cultured renal tubular epithelial NRK-52E cells, ox-Alb triggered cell death, associated with increased intracellular albumin accumulation—enhanced cellular protein carbonylation, and p38 MAPK activation. Notably, ox-Alb induced ferroptosis, evidenced by decreased GPX4 and xCT, increased ACSL4, elevated iron and lipid peroxidation, and suppression by deferoxamine and liproxstatin-1. In vivo, administration of ox-Alb exacerbated doxorubicin-induced nephropathy, as indicated by the elevated BUN, creatinine, and proteinuria, and intensified renal ferroptotic responses, including altered GPX4 and ACSL4. Our findings demonstrate that ox-Alb induces renal cell ferroptosis and promotes renal disease progression, suggesting its pivotal pathogenic role in oxidative stress-related kidney diseases. Full article

Volatile anesthetics, while increasingly utilized in intensive care medicine, are associated with significant renal adverse effects. A critical safety concern—particularly with sevoflurane—involves its potential impact on renal function. Pathophysiologically, inorganic fluoride levels exceeding 50 µmol/L are recognized as a threshold for nephrogenic diabetes insipidus, a condition generally considered reversible. Additionally, the sevoflurane degradation product “compound A” has been implicated in direct renal tubular and glomerular toxicity. Specifically, exposure has been correlated with glomerular damage, evidenced by albuminuria, as well as injury to both proximal and distal tubules, indicated by elevated levels of α-glutathione-S-transferase. Postprandial glycosuria may also be observed. Unlike nephrogenic diabetes insipidus, the structural damage induced by compound A may result in irreversible renal impairment. Full article

Background: Quasipaa spinosa crude extract (QSce), a natural source rich in proteins such as parvalbumin (PV), has been traditionally used to promote physical recovery. However, its mechanisms in mitigating exercise-induced fatigue remain unclear. Methods: Using a murine treadmill exhaustion model, we evaluated the effects of QS-derived Parvalbumin (QsPV) (30 and 150 mg/kg/day) on endurance capacity, oxidative stress, tissue injury, and muscle function. Indicators measured included time to exhaustion, intracellular calcium levels, antioxidant enzymes [superoxide dismutase (SOD), glutathione peroxidase (GSH-Px)], lipid peroxidation (malondialdehyde, MDA), injury markers [creatine kinase (CK), lactate dehydrogenase (LDH), cardiac troponin I (cTnI)], renal function (blood urea), and muscle force. Results: QsPV-150 significantly increased time to exhaustion by 34.6% compared to the exercise-only group (p < 0.01). It reduced MDA by 41.2% in skeletal muscle and increased SOD and GSH-Px levels by 35.4% and 28.1%, respectively. Serum CK, LDH, and cTnI were reduced by 39.5%, 31.7%, and 26.8%, respectively, indicating protection against muscle and cardiac injury. QsPV also decreased blood urea by 22.3% and improved renal histology, with reduced glomerular damage and tubular lesions. At the molecular level, QsPV restored calcium balance and downregulated calpain-1/2 and atrophy-related genes (MuRF-1, MAFbx-32). Muscle contractile force (GAS and SOL) improved by 12.2–20.3%. Conclusions: QsPV attenuates exercise-induced fatigue through multi-organ protection involving calcium buffering, oxidative stress reduction, and anti-atrophy effects. These findings support its potential as a natural recovery-enhancing supplement, pending further clinical and pharmacokinetic studies. Full article

Metabolic syndrome (MetS), characterized by obesity, insulin resistance, and dyslipidemia, is a major risk factor for renal injury. Oxidative stress (OxS) plays a pivotal role in its progression; however, the underlying molecular mechanisms are not fully understood. In this study, we established a rat model of MetS using a high-fat diet combined with a single-dose streptozotocin injection in male Wistar rats. MetS rats exhibited systemic OxS, evidenced by elevated circulating levels of free oxygen radicals and decreased antioxidant defense capacity, as well as hypertension, renal lipid peroxidation, glomerular hyperfiltration, and renal tubular injury. Transcriptomic profiling of renal tissue revealed significant downregulation of six OxS-related genes: C-C motif chemokine ligand 5 (CCL5), glutamate-cysteine ligase catalytic subunit, glutathione peroxidase 6, recombination activating gene 2, NAD(P)H: quinone oxidoreductase 1, and selenoprotein P-1. Among these downregulated genes, CCL5 was further confirmed to be repressed at both mRNA and protein levels across intrarenal and systemic compartments. Given its documented functions in immune signaling and redox homeostasis, CCL5 downregulation may contribute to enhanced oxidative damage in MetS-associated renal injury. These findings highlight the role of redox gene dysregulation in the pathogenesis of MetS-related kidney disease and support the potential of CCL5 as a biomarker for oxidative renal injury. Full article

Studies on populations exposed to inorganic arsenic (iAs) have shown an association with the development of chronic kidney disease (CKD) and renal cell carcinoma (RCC). However, there are few studies addressing how acute exposure of the human kidney to iAs might lead to the long-term alterations that might lead to CKD or RCC. This laboratory’s hypothesis is that renal exposure to iAs might alter the renal cells responsible for the repair and regeneration of nephrons damaged by iAs exposure or other renal toxicants. The kidney possesses a minority epithelial cell population that co-expresses PROM1 and CD24, which are believed to be involved in renal epithelial cell repair. The purpose of this work is to understand the pathogenesis of CKD in renal cortical epithelial cells. Our model consists of acute and chronic exposure of i-As (III) to “Human Renal Tubular Precursor TERT” (HRTPT). The microarray and gene validation study demonstrated a sudden induction of microfibril associated protein 5 (MFAP5) and carcinoembryonic antigen related cell adhesion molecule 5 and 6 (CEACAM 5 and 6) in chronic i-As (III)-exposed cells. Chronically exposed cells also exhibited an induction of the pAKT/AKT pathway and SOX9 transcription factor. The targeting of MFAP5 and CEACAM 5/6 could, therefore, provide a potential therapeutic approach to CKD. Full article

Dogs with acute congestive heart failure (CHF) can develop acute kidney injury (AKI); the prevalence of this condition has not been defined. This study aimed to assess the occurrence of AKI (increase in serum creatinine (sCr) ≥ 0.3 mg/dL) within 48 h from admission in dogs with myxomatous mitral valve disease (MMVD) with acute CHF, and the role of urinary neutrophil gelatinase-associated lipocalin (uNGAL) as a predictive marker of AKI. This was a multicentric, prospective observational study. Thirty dogs were included. The types and dosages of the diuretics administered, as well as the serum and urinary chemistry, including uNGAL and uNGAL, to the urinary creatinine ratio (uNGALC), were determined at admission (T0) and after 24 (T24) and 48 (T48) hours of hospitalization. Nineteen dogs developed AKI. We found no statistically significant differences in sCr, uNGAL, uNGALC, diuretic dosage, or hours of hospitalization between dogs that developed AKI and those that did not. The urinary NGAL and uNGALC values were not statistically significantly different at any time point, while the sCr was higher at T24 and T48 than T0. Our findings suggest that AKI in MMVD dogs with CHF is primarily functional, driven by effective decongestion rather than severe tubular damage, with the benefits of decongestion outweighing transient increases in sCr. Full article