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Nazareno Carullo,1 Maria Teresa Zicarelli,1 Alessandro Casarella,2 Ramona Nicotera,1 Alberto Castagna,2 Alessandra Urso,1 Pierangela Presta,1 Michele Andreucci,1 Emilio Russo,2 Davide Bolignano,1 Giuseppe Coppolino1 1Renal Unit, Department of Health Sciences, “Magna Graecia” University, Catanzaro, Italy; 2Department of Health Sciences, “Magna Graecia” University, Catanzaro, ItalyCorrespondence: Giuseppe CoppolinoRenal Unit, Department of Health Sciences, “Magna Graecia” University, Viale Europa - Germaneto, Catanzaro, 88100, ItalyTel +39 09613697170Email gcoppolino@unicz.itAbstract: Autosomal dominant polycystic kidney disease (ADPKD) is the most frequent single-gene disorder leading to renal failure. Current therapies are aimed to treat renal and extrarenal complications of ADPKD, but improved knowledge of the pathophysiological mechanisms leading to the generation and growth of cysts has permitted the identification of new drug candidates for clinical trials. Among these, in this review, we will examine above all the role of metformin, hypothesized to be able to activate the AMP-activated protein kinase (AMPK) pathway and potentially modulate some mechanisms implicated in the onset and the growth of the cysts.Keywords: cystogenesis, renal cells, metformin, chronic renal disease, renal tubule

Renee Hartog,1,* Davide Bolignano,1,2,* Eric Sijbrands,1 Giacomo Pucci,3,4 Francesco Mattace-Raso1 1Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, the Netherlands; 2Institute of Clinical Physiology, Italian National Council of Research, Reggio Calabria, Italy; 3Department of Medicine, University of Perugia, Perugia, Italy; 4Unit of Internal Medicine, Terni University Hospital, Terni, Italy *These authors contributed equally to this work Background: Vascular aging is known to induce progressive stiffening of the large elastic arteries, altering vascular hemodynamics under both rest and stress conditions. In this study, we aimed to investigate changes in vascular hemodynamics in response to isometric handgrip exercise across ages.Participants and methods: We included 62 participants, who were divided into three age categories: 20–40 (n=22), 41–60 (n=20), and 61–80 (n=20) years. Vascular hemodynamics were measured using the Mobil-o-Graph® based on the pulsatile pressure changes in the brachial artery. One-way ANOVA test was performed to analyze the changes induced by isometric handgrip exercise.Results: After isometric handgrip exercise, aortic pulse wave velocity (PWV) increased by 0.10 m/s in the youngest, 0.06 m/s in the middle-age, and 0.02 m/s in the oldest age category. Changes in PWV strongly correlated with those in central systolic blood pressure (cSBP) (r=0.878, P

Background: Autosomal dominant polycystic kidney disease (ADPKD) is the leading inherited cause of kidney disease. Clinical management has historically focused on symptom control and reducing associated complications. Improved understanding of the molecular and cellular mechanisms involved in kidney cyst growth and disease progression has resulted in new pharmaceutical agents targeting disease pathogenesis and preventing disease progression. However, the role of disease-modifying agents for all people with ADPKD is unclear. This is an update of a review first published in 2015., Objectives: We aimed to evaluate the benefits and harms of interventions to prevent the progression of ADPKD and the safety based on patient-important endpoints, defined by the Standardised Outcomes in NephroloGy-Polycystic Kidney Disease (SONG-PKD) core outcome set, and general and specific adverse effects., Search Methods: We searched the Cochrane Kidney and Transplants Register of Studies up to 13 August 2024 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Registry Platform (ICTRP) Search Portal, and ClinicalTrials.gov., Selection Criteria: Randomised controlled trials (RCTs) comparing any interventions for preventing the progression of ADPKD with other interventions, placebo, or standard care were considered for inclusion., Data Collection and Analysis: Two authors independently assessed study risks of bias and extracted data. Summary estimates of effects were obtained using a random-effects model, and results were expressed as risk ratios (RR) and their 95% confidence intervals (CI) for dichotomous outcomes and mean difference (MD) or standardised mean difference (SMD) and 95% CI for continuous outcomes. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach., Main Results: We included 57 studies (8016 participants) that investigated 18 pharmacological interventions (vasopressin 2 receptor (V2R) antagonists, antihypertensive therapy, mammalian target of rapamycin (mTOR) inhibitors, somatostatin analogues, antiplatelet agents, eicosapentaenoic acids, statins, kinase inhibitors, diuretics, anti-diabetic agents, water intake, dietary intervention, and supplements) in this review. Compared to placebo, the V2R antagonist tolvaptan probably preserves eGFR (3 studies, 2758 participants: MD 1.26 mL/min/1.73 m 2 , 95% CI 0.73 to 1.78; I 2 = 0%) and probably slows total kidney volume (TKV) growth in adults (1 study, 1307 participants: MD -2.70 mL/cm, 95% CI -3.24 to -2.16) (moderate certainty evidence). However, there was insufficient evidence to determine tolvaptan's impact on kidney failure and death. There may be no difference in serious adverse events; however, treatment probably increases nocturia, fatigue and liver enzymes, may increase dry mouth and thirst, and may decrease hypertension and urinary and upper respiratory tract infections. Data on the impact of other therapeutic interventions were largely inconclusive. Compared to placebo, somatostatin analogues probably decrease TKV (6 studies, 500 participants: SMD -0.33, 95% CI -0.51 to -0.16; I 2 = 11%), probably have little or no effect on eGFR (4 studies, 180 participants: MD 4.11 mL/min/1.73 m 3 , 95% CI -3.19 to 11.41; I 2 = 0%) (moderate certainty evidence), and may have little or no effect on kidney failure (2 studies, 405 participants: RR 0.64, 95% CI 0.16 to 2.49; I 2 = 39%; low certainty evidence). Serious adverse events may increase (2 studies, 405 participants: RR 1.81, 95% CI 1.01 to 3.25; low certainty evidence). Somatostatin analogues probably increase alopecia, diarrhoea or abnormal faeces, dizziness and fatigue but may have little or no effect on anaemia or infection. The effect on death is unclear. Targeted low blood pressure probably results in a smaller per cent annual increase in TKV (1 study, 558 participants: MD -1.00, 95% CI -1.67 to -0.33; moderate certainty evidence) compared to standard blood pressure targets, had uncertain effects on death, but probably do not impact other outcomes such as change in eGFR or adverse events. Kidney failure was not reported. Data comparing antihypertensive agents, mTOR inhibitors, eicosapentaenoic acids, statins, vitamin D compounds, metformin, trichlormethiazide, spironolactone, bosutinib, curcumin, niacinamide, prescribed water intake and antiplatelet agents were sparse and inconclusive. An additional 23 ongoing studies were also identified, including larger phase III RCTs, which will be assessed in a future update of this review., Authors' Conclusions: Although many interventions have been investigated in patients with ADPKD, at present, there is little evidence that they improve patient outcomes. Tolvaptan is the only therapeutic intervention that has demonstrated the ability to slow disease progression, as assessed by eGFR and TKV change. However, it has not demonstrated benefits for death or kidney failure. In order to confirm the role of other therapeutic interventions in ADPKD management, large RCTs focused on patient-centred outcomes are needed. The search identified 23 ongoing studies, which may provide more insight into the role of specific interventions., (Copyright © 2024 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.)

Background and Objectives: Acute kidney injury (AKI) remains a significant complication following major cardiac surgery. Marinobufagenin (MBG), a cardiotonic steroid involved in sodium balance and blood pressure regulation, has been linked to organ damage after ischemia-reperfusion events. This pilot, prospective study investigates the utility of circulating MBG to improve AKI risk assessment in cardiac surgery patients as a stand-alone biomarker and after inclusion in a validated risk model (STS-AKI score). Materials and Methods: We included 45 patients undergoing elective cardiac surgery. The MBG levels were measured preoperatively and at 4, 8, and 12 h post-surgery. The AKI was defined according to the KDIGO guidelines. Statistical analyses assessed the diagnostic and prognostic utility of MBG and its integration with the STS-AKI score. Results: An AKI occurred in 26.7% of the patients. The STS-AKI score performed well in this cohort (AUC: 0.736). The MBG levels displayed a decreasing trend in the whole population after surgery ( p = 0.02). However, in the AKI patients, MBG increased at 4 and 8 h before decreasing at 12 h post-surgery. The MBG changes from the baseline to 8 h and from 8 to 12 h post-surgery showed a remarkable diagnostic accuracy for an AKI (AUCs: 0.917 and 0.843, respectively). Integrating these MBG changes with the STS-AKI score significantly improved the model performance, including discrimination, calibration, and risk reclassification. Conclusions : The MBG measurement, particularly any dynamic changes post-surgery, enhances AKI risk stratification in cardiac surgery patients. Integrating MBG with the STS-AKI score offers more accurate risk predictions, potentially leading to better patient management and outcomes.

Background and Objectives : Selenium deficiency represents a risk factor for the occurrence of severe diseases, such as acute kidney injury (AKI). Recently, selenoprotein-p1 (SEPP1), a selenium transporter, mainly released by the liver, has emerged as a promising plasmatic biomarker of AKI as a consequence of cardio-surgery operations. The aim of the present study was to investigate, on an in vitro model of hypoxia induced in renal tubular cells, HK-2, the effects of sodium selenite (Na 2 SeO 3 ) and to evaluate the expression of SEPP1 as a marker of injury. Materials and Methods : HK-2 cells were pre-incubated with 100 nM Na 2 SeO 3 for 24 h, and then, treated for 24 h with CoCl 2 (500 µM), a chemical hypoxia inducer. The results were derived from an ROS assay, MTT, and Western blot analysis. Results : The pre-treatment determined an increase in cells' viability and a reduction in reactive oxygen species (ROS), as shown by MTT and the ROS assay. Moreover, by Western blot an increase in SEPP1 expression was observed after hypoxic injury as after adding sodium selenite. Conclusions : Our preliminary results shed light on the possible role of selenium supplementation as a means to prevent oxidative damage and to increase SEPP1 after acute kidney injury. In our in vitro model, SEPP1 emerges as a promising biomarker of kidney injury, although further studies in vivo are necessary to validate our findings.

Chronic kidney disease (CKD) is a disorder that causes changes in both the structure and function of the kidneys, causing complications such as hypertension, edema, and oliguria. Renal fibrosis is also a common pathological feature of CKD. Matrix metalloproteinases (MMPs) are endopeptidases that degrade extracellular matrix (ECM) proteins. The proteinase domain consists of a zinc ion in the active site, which contributes to its stabilization with another zinc and three calcium structural ions. Many cellular processes are controlled by MMPs, such as cell-cell interactions and various signaling pathways, while they are also involved in degrading substrates on cell surfaces. Tissue inhibitors of metalloproteinases (TIMPs) are key regulators of metalloproteinases, and both are involved in regulating cell turnover, the regulation, and the progression of fibrosis and apoptosis in the tissue. MMPs play a role in renal fibrosis, such as the tubular cell epithelial-mesenchymal transition (TEM), activation of resident fibroblasts, endothelial-mesenchymal transition (EndoMT), and pericyte-myofibroblast transdifferentiation. This review aims to show the mechanisms through which MMPs contribute to renal fibrosis, paying particular attention to MMP-9 and the epithelial-mesenchymal transition., Competing Interests: The authors declare no conflict of interest. Raffaele Serra is serving as one of the Editorial Board members of this journal. We declare that Raffaele Serra had no involvement in the peer review of this article and has no access to information regarding its peer review. Full responsibility for the editorial process for this article was delegated to Amancio Carnero Moya., (© 2024 The Author(s). Published by IMR Press.)

Background : Biomarkers development for prognostication or prediction of perioperative myocardial disease is critical for the evolution of treatment options in patients undergoing cardiac surgery. The aim of our prospective monocentric study was to investigate the role of selenoprotein 1 (SEEP 1) as a potential biomarker for assessing the risk of myocardial injury after cardiac surgery. Methods : Circulating SEPP1 was measured in the blood of 45 patients before surgery and at 4 h, 8 h and 12 h after CPB by enzyme-linked immunosorbent assay (ELISA); (3) Results : circulating SEPP-1 levels measured 4 h after surgery were strongly correlated with CK-MB levels measured at 48 h (R = 0.598, p < 0.0001) and at 72 h (R = 0.308, p = 0.05). Close correlations were also found between 4 h SEPP-1 and Hs-c troponin values measured at 24 h (R = 0.532, p < 0.0001), 48 h (R = 0.348, p = 0.01) and 72 h (R = 0.377, p = 0.02), as well as with cardiopulmonary bypass (CPB) (R = 0.389, p = 0.008) and cross-clamp time (R = 0.374, p = 0.001); (4) Conclusions : Early SEPP1 measurement after CPB may hold great potential for identifying cardiac surgery patients at risk of developing perioperative myocardial injury.

Background and Objectives: A novel post-translational modification (PTM) fragment derived from the cleavage of Fetuin-A (PTM-FetA) has recently emerged as a sensitive biomarker for kidney damage in diabetic patients, but evidence in other chronic renal diseases is lacking. In this pilot study, we aimed at evaluating the clinical significance of urinary PTM-FetA (uPTM-FetA) in a mixed cohort of patients with non-advanced chronic kidney disease (CKD) secondary to diabetic kidney disease (DKD) or other causes. Materials and Methods: We enrolled 47 adult patients with CKD (mean CKD-Epi 40.10 ± 16.5 mL/min/1.73 m 2 ) due to DKD ( n = 34) or other etiology ( n = 13). uPTM-FetA was measured in the urine using a commercially available ELISA kit. Fifteen healthy individuals served as controls. Results: Collectively, all CKD patients displayed remarkably higher levels of uPTM-FetA than controls (0.84 [0.10-1.15] vs. 29.68 [2.50-55.16] ng/mL p = 0.0005), but values were lower in non-DKD than in DKD patients (1.66 [0.09-4.19] vs. 13.9 [0.01-45.02] ng/mL; p = 0.01). uPTM-FetA showed a great diagnostic capacity at ROC analyses to identify the presence of CKD (AUC 0.776; p < 0.001) and, within CKD patients, to discriminate the diabetic and non-diabetic etiology (AUC 0.673; p = 0.02). At multivariate correlation analyses, proteinuria (β = 0.442; p = 0.02) and BMI (β = -0.334; p = 0.04) were the sole independent predictors of uPTM-FetA in this study population. Conclusions: uPTM-FetA could be a novel sensitive biomarker at the crossroad of chronic renal damage and metabolic dysfunction. Additionally, this biomarker could also represent a non-invasive, complementary tool for discriminating among different CKD etiologies (DKD vs. non-DKD) in difficult cases or when renal biopsy is not available.

Capsaicin, the organic compound which attributes the spicy flavor and taste of red peppers and chili peppers, has been extensively studied for centuries as a potential natural remedy for the treatment of several illnesses. Indeed, this compound exerts well-known systemic pleiotropic effects and may thus bring important benefits against various pathological conditions like neuropathic pain, rhinitis, itching, or chronic inflammation. Yet, little is known about the possible biological activity of capsaicin at the kidney level, as this aspect has only been addressed by sparse experimental investigations. In this paper, we aimed to review the available evidence focusing specifically on the effects of capsaicin on renal physiology, as well as its potential benefits for the treatment of various kidney disorders. Capsaicin may indeed modulate various aspects of renal function and renal nervous activity. On the other hand, the observed experimental benefits in preventing acute kidney injury, slowing down the progression of diabetic and chronic kidney disease, ameliorating hypertension, and even delaying renal cancer growth may set the stage for future human trials of capsaicin administration as an adjuvant or preventive therapy for different, difficult-to-treat renal diseases.

This review examines the impact of childhood obesity on the kidney from an epidemiological, pathogenetic, clinical, and pathological perspective, with the aim of providing pediatricians and nephrologists with the most current data on this topic. The prevalence of childhood obesity and chronic kidney disease (CKD) is steadily increasing worldwide, reaching epidemic proportions. While the impact of obesity in children with CKD is less pronounced than in adults, recent studies suggest a similar trend in the child population. This is likely due to the significant association between obesity and the two leading causes of end-stage renal disease (ESRD): diabetes mellitus (DM) and hypertension. Obesity is a complex, systemic disease that reflects interactions between environmental and genetic factors. A key mechanism of kidney damage is related to metabolic syndrome and insulin resistance. Therefore, we can speculate about an adipose tissue-kidney axis in which neurohormonal and immunological mechanisms exacerbate complications resulting from obesity. Adipose tissue, now recognized as an endocrine organ, secretes cytokines called adipokines that may induce adaptive or maladaptive responses in renal cells, leading to kidney fibrosis. The impact of obesity on kidney transplant-related outcomes for both donors and recipients is also significant, making stringent preventive measures critical in the pre- and post-transplant phases. The challenge lies in identifying renal involvement as early as possible, as it is often completely asymptomatic and not detectable through common markers of kidney function. Ongoing research into innovative technologies, such as proteomics and metabolomics, aims to identify new biomarkers and is constantly evolving. Many aspects of pediatric disease progression in the population of children with obesity still require clarification. However, the latest scientific evidence in the field of nephrology offers glimpses into various new perspectives, such as genetic factors, comorbidities, and novel biomarkers. Investigating these aspects early could potentially improve the prognosis of these young patients through new diagnostic and therapeutic strategies. Hence, the aim of this review is to provide a comprehensive exploration of the pathogenetic mechanisms and prevalent pathological patterns of kidney damage observed in children with obesity.

Background: Physical inactivity and mood disturbances are key issues in individuals with end-stage kidney disease (ESKD) and may lead to poor clinical outcomes., Methods: We performed a pilot, observational study to explore the possible relationships between the self-reported level of physical activity (IPAQ) and the severity of mood disturbances (BDI score) in a cohort of 58 ESKD patients undergoing chronic hemodialysis (HD; n = 30) or peritoneal dialysis (PD; n = 28)., Results: Overall, ESKD patients were severely inactive (median METs: 590 [460-1850]) and the intensity of overall and walking physical activity was mostly low to moderate. HD individuals appeared less active than PD (METs 550 [250-1600] vs. 1080 [750-1730]; p = 0.003) and were also less prone to walking (METs 180 ± 90 vs. 320 ± 100; p = 0.01), while a barely statistical difference was noticed for the time spent sitting. ESKD individuals displayed a median BDI score of 17 [12-21], which indicated, on average, the presence of borderline depression, which was apparently more evident among HD individuals. A strong, inverse correlation was found between self-reported METs and BDI scores (R = -0.78; p < 0.0001), while such scores paralleled the time spent sitting during a weekday (R = 0.45; p = 0.0004) and a weekend day (R = 0.40; p = 0.002)., Conclusions: In ESKD patients on chronic dialysis, physical inactivity and mood disturbances might be significantly inter-connected, thereby amplifying their relative impact on quality of life, dysautonomia and long-term outcomes. Future studies on larger populations are recommended to confirm these preliminary observations. Promoting strategies to improve fitness, along with greater attention to physiological aspects, should be incorporated into the clinical management of ESKD patients.

Background: Despite patients undergoing chronic hemodialysis (HD) being notoriously prone to adverse cardiovascular (CV) events, risk prediction in this population remains challenging. miRNA 122-5p, a short, non-coding RNA predominantly involved in lipid and carbohydrate metabolism, has recently been related to the onset and progression of CV disease., Methods: We run a pilot, multicenter, longitudinal, observational study to evaluate the clinical significance and prognostic usefulness of circulating miRNA 122-5p in a multicentric cohort of 74 individuals on maintenance HD., Results: Patients displayed lower circulating miRNA 122-5p as compared to healthy controls ( p = 0.004). At correlation analyses, ALT (β = 0.333; p = 0.02), E/e' (β = 0.265; p = 0.02) and CRP (β = -0.219; p = 0.041) were independent predictors of miRNA 122-5p levels. During a median follow-up of 22 months (range of 1-24), 30 subjects (40.5%) experienced a composite endpoint of all-cause mortality and fatal/non-fatal CV events. Baseline circulating miRNA 122-5p was higher in these subjects ( p = 0.01) and it predicted a significantly higher risk of endpoint occurrence (Kaplan-Meier crude HR 3.192; 95% CI 1.529-6.663; p = 0.002; Cox regression adjusted HR 1.115; 95% CI 1.009-1.232; p = 0.03)., Conclusions: Altered miRNA 122-5p levels in HD patients may reflect hepatic and CV damage and may impart important prognostic information for improving CV risk prediction in this particular setting.