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Morella spathulata (Myricaceae family) is a common plant from Madagascar and is present on the IUCN Red List of threatened species classified at the 'least concern' level, used by the local population to treat numerous illnesses and pain. Despite its frequent use, comprehensive phytochemical and pharmacological research on the species is limited. This study evaluated the antioxidant, analgesic, and anti-inflammatory properties, as well as the toxicity of methanol extracts from the leaves (MS_L) and bark (MS_B) of M. spathulata . The research involved the analysis of nutritional traits such as sugars, organic acids, vitamin C, polyphenolic content (TPC) and the main phytochemicals by HPLC analysis. Antioxidant capacity was assessed through DPPH and FRAP assays. Analgesic and anti-inflammatory activities were evaluated using acetic acid-induced writhing and carrageenan-induced paw oedema tests in mice. The results showed a high content of phenolic and bioactive components in the leaf and bark extracts, associated with antioxidant, analgesic and anti-inflammatory properties. The interaction of key compounds such as ferulic acid and ellagic acid with proteins involved in pH regulation and immune modulation provides clues to the mechanisms underlying the therapeutic effects. However, conservation efforts are crucial due to habitat loss and illegal logging, and further studies are needed to fully explore the plant's therapeutic potential.

Objective: Acute appendicitis is a wide spectrum disease, from simple inflammation to evident intestinal perforation. The correct interpretation of the degree of inflammation is crucial to guarantee appropriate treatment and adherence to protocols and guidelines. In order to investigate this concordance, the authors compared the definition of appendicitis and the predicted treatment among all surgeons affiliated to a single Pediatric Surgery School (consisting of 8 different centers)., Design: Twenty-two short recordings of intra-operative manipulation of appendices were shown to 56 surgeons, blindly to clinical information. Four items were collected and analyzed: classification of appendicitis, type and length of predicted antibiotic therapy, day of re-alimentation. Data were analyzed to identify the concordance kappa coefficient, stratified according to expertise of the responding surgeon., Results: The 1232 evaluations obtained in all valued items low overall concordance. Subgroup analysis identified a good agreement between younger surgeons only in the choice of antibiotic (k 0.47). However, if the centers were divided between University and non-University Hospitals, a strong agreement was found in the former both for classification (k 0.45 vs 0.32) and type of antibiotic (k 0.42 vs 0.24)., Conclusions: The overall concordance between surgeons in different centers in the diagnostic classification and predicted treatment of appendicitis is quite low. University Hospital have a highest concordance in both items at all levels of expertise; it might be postulated that teaching to younger surgeon increase the comparison between experts and finally the concordance and adherence to protocols within the center., (Copyright © 2024 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.)

Aims: Renal and liver congestion are associated with adverse outcomes in patients with tricuspid regurgitation (TR). Currently, there are no valid sonographic indicators of fluid status in this population. Intra-renal venous Doppler (IRVD) is a novel method for quantifying renal congestion but its interpretation can be challenging in severe TR due to altered haemodynamics. This study explores the potential of portal vein Doppler (PVD) as an alternative marker for decongestion during volume removal in patients with severe TR., Methods and Results: Forty-two patients with severe TR undergoing decongestive therapy were prospectively enrolled. Inferior vena cava diameter, PVD, and IRVD were sequentially assessed during volume removal. Improvement criteria were portal vein pulsatility fraction (PVPF) < 70% and renal venous stasis index (RVSI) < 0.5 for partial improvement, and PVPF < 30% and RVSI < 0.2 for complete improvement. After volume removal, PVPF significantly improved from 130 ± 39% to 47 ± 44% (P < 0.001), while IRVD improved from 0.72 ± 0.08 to 0.54 ± 0.22 (P < 0.001). A higher proportion of patients displayed improvement in PVD compared to IRVD (partial: 38% vs. 29%, complete: 41% vs. 7%) (P < 0.001). Intra-renal venous Doppler only improved in patients with concomitant improvement in severe TR. Portal vein Doppler was the only predictor of achieving ≥5 L of negative fluid balance [area under the ROC curve (AUC) 0.83 P = 0.001]., Conclusion: This proof-of-concept study suggests that PVD is the only sonographic marker that can track volume removal in severe TR, offering a potential indicator for decongestion in this population. Further intervention trials are warranted to determine if PVD-guided decongestion improves patient outcomes in severe TR., Competing Interests: Conflict of interest: none declared., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Cardiology. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Background: Invasive fungal disease (IFD) is typically aggressive and related with high mortality in children with a hematological malignancy. The association of medical and surgical treatment may ameliorate the outcome. The aim of this study was to analyze the surgical treatment of fungal infections in pediatric oncological populations., Methods: Retrospective study (2000-2022) of a single-center experience. We reviewed the medical record of all patients with hematologic malignancies and IFD, analyzing the outcome., Results: From the 70 pediatric cases of hematologic malignancies with the diagnosis IFD over 22 years, we included in the present study 44 cases who required surgical approaches for either diagnosis or treatment. Twenty-one patients were males and the mean age was 11 (range 1-23) years. The main indications for surgery were lack of improvement following medical treatment and/or progression of fungal infection (80%) and diagnosis confirmation (20%). Only five patients needed an emergency operation for rapid worsening of symptoms. The most common site of infection was the lung (80%) and the most frequently identified pathogen was Aspergillus (75%). The most common surgical procedures were lobectomy (performed in 17 patients) and atypical lung resection (10). Complications of surgery were mostly treated by medical approach. The mean time of resumption of oncological treatment was 40 (range 0-150) days., Conclusions: Surgery is an important step in the multimodal treatment of invasive fungal infection with excellent resolution rate. Overall mortality depends on the underlying malignancy., (© 2024 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Severe cases of COVID-19 are characterized by development of acute respiratory distress syndrome (ARDS). Water accumulation in the lungs is thought to occur as consequence of an exaggerated inflammatory response. A possible mechanism could involve decreased activity of the epithelial Na+ channel, ENaC, expressed in type II pneumocytes. Reduced transepithelial Na+ reabsorption could contribute to lung edema due to reduced alveolar fluid clearance. This hypothesis is based on the observation of the presence of a novel furin cleavage site in the S protein of SARS-CoV-2 that is identical to the furin cleavage site present in the alpha subunit of ENaC. Proteolytic processing of αENaC by furin-like proteases is essential for channel activity. Thus, competition between S protein and αENaC for furin-mediated cleavage in SARS-CoV-2-infected cells may negatively affect channel activity. Here we present experimental evidence showing that coexpression of the S protein with ENaC in a cellular model reduces channel activity. In addition, we show that bidirectional competition for cleavage by furin-like proteases occurs between 〈ENaC and S protein. In transgenic mice sensitive to lethal SARS-CoV-2, however, a significant decrease in gamma ENaC expression was not observed by immunostaining of lungs infected as shown by SARS-CoV2 nucleoprotein staining., Competing Interests: During these studies, G. Gamba received unrelated support from the National Institutes of Health (grant DK51496). D. Batlle and J. Wysocki are coinventors of patents entitled “Active low molecular weight variants of angiotensin converting enzyme 2 (ACE2), “Soluble ACE2 variants and uses therefor.” D. Batlle is founder of Angiotensin Theraputics, Inc. D. Batlle has received consulting fees from Advience and Traveri, all unrelated to this work. During these studies, D. Batlle received unrelated support from the National Institute of Diabetes and Digestive and Kidney Diseases (grant R01DK104785) and from a grant from AstraZeneca. D. Batlle also reports research funding from the Feinberg Foundation; J. Wysocki reports being a scientific advisor for Angiotensin Therapeutics, Inc. All other authors have nothing to disclose. This does not alter our adherence to PLOS ONE policies on sharing data and materials., (Copyright: © 2024 Magaña-Ávila et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Coping with dementia requires an integrated approach encompassing personal, health, research, and community domains. Here we describe "Walking the Talk for Dementia," an immersive initiative aimed at empowering people with dementia, enhancing dementia understanding, and inspiring collaborations. This initiative involved 300 participants from 25 nationalities, including people with dementia, care partners, clinicians, policymakers, researchers, and advocates for a 4-day, 40 km walk through the Camino de Santiago de Compostela, Spain. A 2-day symposium after the journey provided novel transdisciplinary and horizontal structures, deconstructing traditional hierarchies. The innovation of this initiative lies in its ability to merge a physical experience with knowledge exchange for diversifying individuals' understanding of dementia. It showcases the transformative potential of an immersive, embodied, and multi-experiential approach to address the complexities of dementia collaboratively. The initiative offers a scalable model to enhance understanding, decrease stigma, and promote more comprehensive and empathetic dementia care and research., (© 2024 The Authors. Alzheimer's & Dementia published by Wiley Periodicals LLC on behalf of Alzheimer's Association.)

Kidney-specific with-no-lysine kinase 1 (KS-WNK1) is an isoform of WNK1 kinase that is predominantly found in the distal convoluted tubule of the kidney. The precise physiological function of KS-WNK1 remains unclear. Some studies have suggested that it could play a role in regulating potassium renal excretion by modulating the activity of the Na + -Cl - cotransporter (NCC). However, changes in the potassium diet from normal to high failed to reveal a role for KS-WNK1, but under a normal-potassium diet, the expression of KS-WNK1 is negligible. It is only detectable when mice are exposed to a low-potassium diet. In this study, we investigated the role of KS-WNK1 in regulating potassium excretion under extreme changes in potassium intake. After following a zero-potassium diet (0KD) for 10 days, KS-WNK1 -/- mice had lower plasma levels of K + and Cl - while exhibiting higher urinary excretion of Na + , Cl - , and K + compared with KS-WNK1 +/+ mice. After 10 days of 0KD or normal-potassium diet (NKD), all mice were challenged with a high-potassium diet (HKD). Plasma K + levels markedly increased after the HKD challenge only in mice previously fed with 0KD, regardless of genotype. KSWNK1 +/+ mice adapt better to HKD challenge than KS-WNK1 -/- mice after a potassium-retaining state. The difference in the phosphorylated NCC-to-NCC ratio between KS-WNK1 +/+ and KS-WNK1 -/- mice after 0KD and HKD indicates a role for KS-WNK1 in both NCC phosphorylation and dephosphorylation. These observations show that KS-WNK1 helps the distal convoluted tubule to respond to extreme changes in potassium intake, such as those occurring in wildlife. NEW & NOTEWORTHY The findings of this study demonstrate that kidney-specific with-no-lysine kinase 1 plays a role in regulating urinary electrolyte excretion during extreme changes in potassium intake, such as those occurring in wildlife.  .

Vasopressin regulates water homeostasis via the V2 receptor in the kidney at least in part through protein kinase A (PKA) activation. Vasopressin, through an unknown pathway, upregulates the activity and phosphorylation of Na + -Cl - cotransporter (NCC) and Na + -K + -2Cl - cotransporter 2 (NKCC2) by Ste20-related proline/alanine-rich kinase (SPAK) and oxidative stress-responsive kinase 1 (OSR1), which are regulated by the with-no-lysine kinase (WNK) family. Phosphorylation of WNK4 at PKA consensus motifs may be involved. Inhibitor 1 (I1), a protein phosphatase 1 (PP1) inhibitor, may also play a role. In human embryonic kidney (HEK)-293 cells, we assessed the phosphorylation of WNK4, SPAK, NCC, or NKCC2 in response to forskolin or desmopressin. WNK4 and cotransporter phosphorylation were studied in desmopressin-infused WNK4 -/- mice and in tubule suspensions. In HEK-293 cells, only wild-type WNK4 but not WNK1, WNK3, or a WNK4 mutant lacking PKA phosphorylation motifs could upregulate SPAK or cotransporter phosphorylation in response to forskolin or desmopressin. I1 transfection maximized SPAK phosphorylation in response to forskolin in the presence of WNK4 but not of mutant WNK4 lacking PP1 regulation. We observed direct PP1 regulation of NKCC2 dephosphorylation but not of NCC or SPAK in the absence of WNK4. WNK4 -/- mice with desmopressin treatment did not increase SPAK/OSR1, NCC, or NKCC2 phosphorylation. In stimulated tubule suspensions from WNK4 -/- mice, upregulation of pNKCC2 was reduced, whereas upregulation of SPAK phosphorylation was absent. These findings suggest that WNK4 is a central node in which kinase and phosphatase signaling converge to connect cAMP signaling to the SPAK/OSR1-NCC/NKCC2 pathway. NEW & NOTEWORTHY With-no-lysine kinases regulate the phosphorylation and activity of the Na + -Cl - and Na + -K + -2Cl - cotransporters. This pathway is modulated by arginine vasopressin (AVP). However, the link between AVP and WNK signaling remains unknown. Here, we show that AVP activates WNK4 through increased phosphorylation at putative protein kinase A-regulated sites and decreases its dephosphorylation by protein phosphatase 1. This work increases our understanding of the signaling pathways mediating AVP actions in the kidney.

The renal Na-K-2Cl and Na-Cl cotransporters are the major salt reabsorption pathways in the thick ascending limb of Henle loop and the distal convoluted tubule, respectively. These transporters are the target of the loop and thiazide type diuretics extensively used in the world for the treatment of edematous states and arterial hypertension. The diuretics appeared in the market many years before the salt transport systems were discovered. The evolving of the knowledge and the cloning of the genes encoding the Na-K-2Cl and Na-Cl cotransporters were possible thanks to the study of marine species. This work presents the history of how we came to know the mechanisms for the loop and thiazide type diuretics actions, the use of marine species in the cloning process of these cotransporters and therefore in the whole solute carrier cotransproters 12 (SLC12) family of electroneutral cation chloride cotransporters, and the disease associated with each member of the family., (Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Society of Nephrology.)

The with-no-lysine kinase 4 (WNK4)-sterile 20/SPS-1-related proline/alanine-rich kinase (SPAK)/oxidative stress-responsive kinase 1 (OSR1) pathway mediates activating phosphorylation of the furosemide-sensitive Na + -K + -2Cl - cotransporter (NKCC2) and the thiazide-sensitive NaCl cotransporter (NCC). The commonly used pT96/pT101-pNKCC2 antibody cross-reacts with pT53-NCC in mice on the C57BL/6 background due to a five amino acid deletion. We generated a new C57BL/6-specific pNKCC2 antibody (anti-pT96-NKCC2) and tested the hypothesis that the WNK4-SPAK/OSR1 pathway strongly regulates the phosphorylation of NCC but not NKCC2. In C57BL/6 mice, anti-pT96-NKCC2 detected pNKCC2 and did not cross-react with NCC. Abundances of pT96-NKCC2 and pT53-NCC were evaluated in Wnk4 -/- , Osr1 -/- , Spak -/- , and Osr1 -/- / Spak -/- mice and in several models of the disease familial hyperkalemic hypertension (FHHt) in which the CUL3-KLHL3 ubiquitin ligase complex that promotes WNK4 degradation is dysregulated ( Cul3 +/-/Δ9 , Klhl3 -/- , and Klhl3 R528H/R528H ). All mice were on the C57BL/6 background. In Wnk4 -/- mice, pT53-NCC was almost absent but pT96-NKCC2 was only slightly lower. pT53-NCC was almost absent in Spak -/- and Osr1 -/- / Spak -/- mice, but pT96-NKCC2 abundance did not differ from controls. pT96-NKCC2/total NKCC2 was slightly lower in Osr1 -/- and Osr1 -/- / Spak -/- mice. WNK4 expression colocalized not only with NCC but also with NKCC2 in Klhl3 -/- mice, but pT96-NKCC2 abundance was unchanged. Consistent with this, furosemide-induced urinary Na + excretion following thiazide treatment was similar between Klhl3 -/- and controls. pT96-NKCC2 abundance was also unchanged in the other FHHt mouse models. Our data show that disruption of the WNK4-SPAK/OSR1 pathway only mildly affects NKCC2 phosphorylation, suggesting a role for other kinases in NKCC2 activation. In FHHt models NKCC2 phosphorylation is unchanged despite higher WNK4 abundance, explaining the thiazide sensitivity of FHHt. NEW & NOTEWORTHY The renal cation cotransporters NCC and NKCC2 are activated following phosphorylation mediated by the WNK4-SPAK/OSR1 pathway. While disruption of this pathway strongly affects NCC activity, effects on NKCC2 activity are unclear since the commonly used phospho-NKCC2 antibody was recently reported to cross-react with phospho-NCC in mice on the C57BL/6 background. Using a new phospho-NKCC2 antibody specific for C57BL/6, we show that inhibition or activation of the WNK4-SPAK/OSR1 pathway in mice only mildly affects NKCC2 phosphorylation.

The solute carrier family 12A (SLC12A) superfamily of membrane transporters modulates the movement of cations coupled with chloride across the membrane. In doing so, these cotransporters are involved in numerous aspects of human physiology: cell volume regulation, ion homeostasis, blood pressure regulation, and neurological action potential via intracellular chloride concentration modulation. Their physiological characterization has been largely studied; however, understanding the mechanics of their function and the relevance of structural domains or specific amino acids has been a pending task. In recent years, single-particle cryogenic electron microscopy (cryo-EM) has been successfully applied to members of the SLC12A family including all K + :Cl - cotransporters (KCCs), Na + :K + :2Cl - cotransporter NKCC1, and recently Na + :Cl - cotransporter (NCC); revealing structural elements that play key roles in their function. The present review analyzes the data provided by these cryo-EM reports focusing on structural domains and specific amino acids involved in ion binding, domain interactions, and other important SCL12A structural elements. A comparison of cryo-EM data from NKCC1 and KCCs is presented in the light of the two recent NCC cryo-EM studies, to propose insight into structural elements that might also be found in NCC and are necessary for its proper function. In the final sections, the importance of key coordination residues for substrate specificity and their implication on various pathophysiological conditions and genetic disorders is reviewed, as this could provide the basis to correlate structural elements with the development of novel and selective treatments, as well as mechanistic insight into the function and regulation of cation-coupled chloride cotransporters (CCCs).

The primary structure of the thiazide-sensitive NaCl cotransporter (NCC) was resolved 30 years ago by the molecular identification of the cDNA encoding this cotransporter, from the winter's flounder urinary bladder, following a functional expression strategy. This review outlines some aspects of how the knowledge about thiazide diuretics and NCC evolved, the history of the cloning process, and the expansion of the SLC12 family of electroneutral cotransporters. The diseases associated with activation or inactivation of NCC are discussed, as well as the molecular model by which the activity of NCC is regulated. The controversies in the field are discussed as well as recent publication of the three-dimensional model of NCC obtained by cryo-electron microscopy, revealing not only the amino acid residues critical for Na + and Cl - translocation but also the residues critical for polythiazide binding to the transporter, opening the possibility for a new era in thiazide diuretic therapy.

Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision.

Competing Interests: Declaration of Competing Interest ERA declares speaker honoraria for GE Healthcare and Echonous. The remaining authors have no conflicts of interest to declare.

Purpose of Review: Regulation of the sodium chloride cotransporter (NCC) in the distal convoluted tubule (DCT) plays a crucial role in renal salt handling. The calcium-sensing receptor (CaSR) has been shown to activate NCC through the WNK4-SPAK pathway, which is independent of the Renin-Angiotensin-Aldosterone system. In this review, we examine new information about the mechanism of how the CaSR regulates NCC through the WNK4-SPAK pathway and its physiological and therapeutic implications., Recent Findings: The activation of CaSR in TALH cells during hypercalcemia inhibits NKCC2 and ROMK activity, reducing paracellular Ca2+ reabsorption but decreasing salt reabsorption. This pathway enables NaCl reabsorption in the DCT while promoting Ca2+ excretion. CaSR activation in the apical DCT stimulates a signaling pathway involving PKC, WNK4, and SPAK, which increases NCC activation to recover the NaCl not reabsorbed in TAHL. Glucose or fructose acting as calcimimetics enhance apical CaSR sensitivity, increasing NCC activity, which contribute to the mechanism of hypertension prevalence in diabetic patients or in those with high fructose consumption., Summary: These findings reveal the importance of the CaSR-mediated activation of the WNK4-SPAK pathway in regulating salt and calcium homeostasis and its potential as a therapeutic target for hypertension and related diseases., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

We previously showed that SerpinA3K is present in urine from rats and humans with acute kidney injury (AKI) and chronic kidney disease (CKD). However, the specific role of SerpinA3K during renal pathophysiology is unknown. To begin to understand the role of SerpinA3K on AKI, SerpinA3K-deficient (KOSA3) mice were studied 24 h after inducing ischemia/reperfusion (I/R) and compared to wild type (WT) mice. Four groups were studied: WT+S, WT+IR, KOSA3+S, and KOSA3+IR. As expected, I/R increased serum creatinine and BUN, with a GFR reduction in both genotypes; however, renal dysfunction was ameliorated in the KOSA3+IR group. Interestingly, the increase in UH 2 O 2 induced by I/R was not equally seen in the KOSA3+IR group, an effect that was associated with the preservation of antioxidant enzymes' mRNA levels. Additionally, FOXO3 expression was initially greater in the KOSA3 than in the WT group. Moreover, the increase in BAX protein level and the decrease in Hif1a and Vegfa induced by I/R were not observed in the KOSA3+IR group, suggesting that these animals have better cellular responses to hypoxic injury. Our findings suggest that SerpinA3K is involved in the renal oxidant response, HIF1α/VEGF pathway, and cell apoptosis.

The thiazide sensitive Na + :Cl - cotransporter (NCC) is the principal via for salt reabsorption in the apical membrane of the distal convoluted tubule (DCT) in mammals and plays a fundamental role in managing blood pressure. The cotransporter is targeted by thiazide diuretics, a highly prescribed medication that is effective in treating arterial hypertension and edema. NCC was the first member of the electroneutral cation-coupled chloride cotransporter family to be identified at a molecular level. It was cloned from the urinary bladder of the Pseudopleuronectes americanus (winter flounder) 30 years ago. The structural topology, kinetic and pharmacology properties of NCC have been extensively studied, determining that the transmembrane domain (TM) coordinates ion and thiazide binding. Functional and mutational studies have discovered residues involved in the phosphorylation and glycosylation of NCC, particularly on the N-terminal domain, as well as the extracellular loop connected to TM7-8 (EL7-8). In the last decade, single-particle cryogenic electron microscopy (cryo-EM) has permitted the visualization of structures at high atomic resolution for six members of the SLC12 family (NCC, NKCC1, KCC1-KCC4). Cryo-EM insights of NCC confirm an inverted conformation of the TM1-5 and TM6-10 regions, a characteristic also found in the amino acid-polyamine-organocation (APC) superfamily, in which TM1 and TM6 clearly coordinate ion binding. The high-resolution structure also displays two glycosylation sites (N-406 and N-426) in EL7-8 that are essential for NCC expression and function. In this review, we briefly describe the studies related to the structure-function relationship of NCC, beginning with the first biochemical/functional studies up to the recent cryo-EM structure obtained, to acquire an overall view enriched with the structural and functional aspects of the cotransporter., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Moreno, Pacheco-Alvarez, Chávez-Canales, Elizalde, Leyva-Ríos and Gamba.)

The activity of the Na + -Cl - cotransporter (NCC) in the distal convoluted tubule (DCT) is finely tuned by phosphorylation networks involving serine/threonine kinases and phosphatases. While much attention has been paid to the With-No-lysine (K) kinase (WNK)- STE20-related Proline Alanine rich Kinase (SPAK)/Oxidative Stress Responsive kinase 1 (OSR1) signaling pathway, there remain many unanswered questions regarding phosphatase-mediated modulation of NCC and its interactors. The phosphatases shown to regulate NCC's activity, directly or indirectly, are protein phosphatase 1 (PP1), protein phosphatase 2A (PP2A), calcineurin (CN), and protein phosphatase 4 (PP4). PP1 has been suggested to directly dephosphorylate WNK4, SPAK, and NCC. This phosphatase increases its abundance and activity when extracellular K + is increased, which leads to distinct inhibitory mechanisms towards NCC. Inhibitor-1 (I1), oppositely, inhibits PP1 when phosphorylated by protein kinase A (PKA). CN inhibitors, like tacrolimus and cyclosporin A, increase NCC phosphorylation, giving an explanation to the Familial Hyperkalemic Hypertension-like syndrome that affects some patients treated with these drugs. CN inhibitors can prevent high K + -induced dephosphorylation of NCC. CN can also dephosphorylate and activate Kelch-like protein 3 (KLHL3), thus decreasing WNK abundance. PP2A and PP4 have been shown in in vitro models to regulate NCC or its upstream activators. However, no studies in native kidneys or tubules have been performed to test their physiological role in NCC regulation. This review focuses on these dephosphorylation mediators and the transduction mechanisms possibly involved in physiological states that require of the modulation of the dephosphorylation rate of NCC., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The handling editor DE declared past co-authorships with the authors., (Copyright © 2023 Carbajal-Contreras, Gamba and Castañeda-Bueno.)

Background: Chronic kidney disease (CKD) represents a substantial global burden of disease due to a lack of universal tests and misinterpretation of biomarkers., Objective: To analyze CKD epidemiology in Mexico and guide public policies., Material and Methods: Data from the Global Burden of Disease (GBD) 2021 study were used to describe CKD prevalence and mortality in Mexico for the 1990-2021 period, stratifying by gender and age groups., Results: The prevalence of CKD in Mexico in 2021 was 9,184.9 per 100,000 population. Diabetes was the most common cause of CKD, and CKD-related mortality was high, with an increase in 2019 and 2021, possibly as a consequence of the COVID-19 pandemic., Conclusions: CKD in Mexico entails a high burden of mortality and years of life lost, but it barely contributes to disability. It is essential to improve CKD early detection, access to treatments and coding of the causes of the disease. Moreover, investigating the causes of CKD of unknown etiology, including genetic factors, is crucial in order for specific treatments to be developed in the future., (Copyright: © 2023 Permanyer.)

Background: The calcium-sensing receptor (CaSR) in the distal convoluted tubule (DCT) activates the NaCl cotransporter (NCC). Glucose acts as a positive allosteric modulator of the CaSR. Under physiologic conditions, no glucose is delivered to the DCT, and fructose delivery depends on consumption. We hypothesized that glucose/fructose delivery to the DCT modulates the CaSR in a positive allosteric way, activating the WNK4-SPAK-NCC pathway and thus increasing salt retention., Methods: We evaluated the effect of glucose/fructose arrival to the distal nephron on the CaSR-WNK4-SPAK-NCC pathway using HEK-293 cells, C57BL/6 and WNK4-knockout mice, ex vivo perfused kidneys, and healthy humans., Results: HEK-293 cells exposed to glucose/fructose increased SPAK phosphorylation in a WNK4- and CaSR-dependent manner. C57BL/6 mice exposed to fructose or a single dose of dapagliflozin to induce transient glycosuria showed increased activity of the WNK4-SPAK-NCC pathway. The calcilytic NPS2143 ameliorated this effect, which was not observed in WNK4-KO mice. C57BL/6 mice treated with fructose or dapagliflozin showed markedly increased natriuresis after thiazide challenge. Ex vivo rat kidney perfused with glucose above the physiologic threshold levels for proximal reabsorption showed increased NCC and SPAK phosphorylation. NPS2143 prevented this effect. In healthy volunteers, cinacalcet administration, fructose intake, or a single dose of dapagliflozin increased SPAK and NCC phosphorylation in urinary extracellular vesicles., Conclusions: Glycosuria or fructosuria was associated with increased NCC, SPAK, and WNK4 phosphorylation in a CaSR-dependent manner., (Copyright © 2022 by the American Society of Nephrology.)

Low potassium intake activates the kidney sodium-chloride cotransporter (NCC) whose phosphorylation and activity depend on the With-No-Lysine kinase 4 (WNK4) that is inhibited by chloride binding to its kinase domain. Low extracellular potassium activates NCC by decreasing intracellular chloride thereby promoting chloride dissociation from WNK4 where residue L319 of WNK4 participates in chloride coordination. Since the WNK4-L319F mutant is constitutively active and chloride-insensitive in vitro, we generated mice harboring this mutation that displayed slightly increased phosphorylated NCC and mild hyperkalemia when on a 129/sv genetic background. On a low potassium diet, upregulation of phosphorylated NCC was observed, suggesting that in addition to chloride sensing by WNK4, other mechanisms participate which may include modulation of WNK4 activity and degradation by phosphorylation of the RRxS motif in regulatory domains present in WNK4 and KLHL3, respectively. Increased levels of WNK4 and kidney-specific WNK1 and phospho-WNK4-RRxS were observed in wild-type and WNK4 L319F/L319F mice on a low potassium diet. Decreased extracellular potassium promoted WNK4-RRxS phosphorylation in vitro and ex vivo as well. These effects might be secondary to intracellular chloride depletion, as reduction of intracellular chloride in HEK293 cells increased phospho-WNK4-RRxS. Phospho-WNK4-RRxS levels were increased in mice lacking the Kir5.1 potassium channel, which presumably have decreased distal convoluted tubule intracellular chloride. Similarly, phospho-KLHL3 was modulated by changes in intracellular chloride in HEK293 cells. Thus, our data suggest that multiple chloride-regulated mechanisms are responsible for NCC upregulation by low extracellular potassium., (Copyright © 2022 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.)

The rapid spread of COVID-19 on all continents and the mortality induced by SARS-CoV-2 virus, the cause of the pandemic coronavirus disease 2019 (COVID-19) has motivated an unprecedented effort for vaccine development. Inactivated viruses as well as vaccines focused on the partial or total sequence of the Spike protein using different novel platforms such us RNA, DNA, proteins, and non-replicating viral vectors have been developed. The high global need for vaccines, now and in the future, and the emergence of new variants of concern still requires development of accessible vaccines that can be adapted according to the most prevalent variants in the respective regions. Here, we describe the immunogenic properties of a group of theoretically predicted RBD peptides to be used as the first step towards the development of an effective, safe and low-cost epitope-focused vaccine. One of the tested peptides named P5, proved to be safe and immunogenic. Subcutaneous administration of the peptide, formulated with alumina, induced high levels of specific IgG antibodies in mice and hamsters, as well as an increase of IFN-γ expression by CD8+ T cells in C57 and BALB/c mice upon in vitro stimulation with P5. Neutralizing titers of anti-P5 antibodies, however, were disappointingly low, a deficiency that we will attempt to resolve by the inclusion of additional immunogenic epitopes to P5. The safety and immunogenicity data reported in this study support the use of this peptide as a starting point for the design of an epitope restricted vaccine., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Xenopus laevis oocytes have been an invaluable tool to discover and explore the molecular mechanisms and characteristics of many proteins, in particular integral membrane proteins. The oocytes were fundamental in many projects designed to identify the cDNA encoding a diversity of membrane proteins including receptors, transporters, channels and pores. In addition to being a powerful tool for cloning, oocytes were later used to experiment with the functional characterization of many of the identified proteins. In this review I present an overview of my personal 30-year experience using Xenopus laevis oocytes and the impact this had on a variety of fields such as arterial blood pressure, neuronal excitability, mineral metabolism and cell volume regulation.

Purpose of Review: The aim of this manuscript was to review recent evidence uncovering the roles of the With No lysine (K) kinase 1 (WNK1) in the kidney., Recent Findings: Analyses of microdissected mouse nephron segments have revealed the abundance of long-WNK1 and kidney-specific-WNK1 transcripts in different segments. The low levels of L-WNK1 transcripts in the distal convoluted tubule (DCT) stand out and support functional evidence on the lack of L-WNK1 activity in this segment. The recent description of familial hyperkalaemic hypertension (FHHt)-causative mutations affecting the acidic domain of WNK1 supports the notion that KS-WNK1 activates the Na+:Cl- cotransporter NCC. The high sensitivity of KS-WNK1 to KLHL3-targeted degradation and the low levels of L-WNK1 in the DCT, led to propose that this type of FHHt is mainly due to increased KS-WNK1 protein in the DCT. The observation that KS-WNK1 renal protein expression is induced by low K+ diet and recent reassessment of the phenotype of KS-WNK1-/- mice suggested that KS-WNK1 may be necessary to achieve maximal NCC activation under this condition. Evidences on the regulation of other renal transport proteins by WNK1 are also summarized., Summary: The diversity of WNK1 transcripts in the kidney has complicated the interpretation of experimental data. Integration of experimental data with the knowledge of isoform abundance in renal cell types is necessary in future studies about WNK1 function in the kidney., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

The thiazide-sensitive Na + -Cl - cotransporter (NCC) is the major pathway for salt reabsorption in the mammalian distal convoluted tubule, and the inhibition of its function with thiazides is widely used for the treatment of arterial hypertension. In mammals and teleosts, NCC is present as one ortholog that is mainly expressed in the kidney. One exception, however, is the eel, which has two genes encoding NCC. The eNCCα is located in the kidney and eNCCβ, which is present in the apical membrane of the rectum. Interestingly, the European eNCCβ functions as a Na + -Cl - cotransporter that is nevertheless resistant to thiazides and is not activated by low-chloride hypotonic stress. However, in the Japanese eel rectal sac, a thiazide-sensitive NaCl transport mechanism has been described. The protein sequences between eNCCβ and jNCCβ are 98% identical. Here, by site-directed mutagenesis, we transformed eNCCβ into jNCCβ. Our data showed that jNCCβ, similar to eNCCβ, is resistant to thiazides. In addition, both NCCβ proteins have high transport capacity with respect to their renal NCC orthologs and, in contrast to known NCCs, exhibit electrogenic properties that are reduced when residue I172 is substituted by A, G, or M. This is considered a key residue for the chloride ion-binding sites of NKCC and KCC. We conclude that NCCβ proteins are not sensitive to thiazides and have electrogenic properties dependent on Cl - , and site I172 is important for the function of NCCβ.

After more than two years, the COVID-19 pandemic is still ongoing and evolving all over the world; human herd immunity against SARS-CoV-2 increases either by infection or by unprecedented mass vaccination. A substantial change in population immunity is expected to contribute to the control of transmission. It is essential to monitor the extension and duration of the population's immunity to support the decisions of health authorities in each region and country, directed to chart the progressive return to normality. For this purpose, the availability of simple and cheap methods to monitor the levels of relevant antibodies in the population is a widespread necessity. Here, we describe the development of an RBD-based ELISA for the detection of specific antibodies in large numbers of samples. The recombinant expression of an RBD-poly-His fragment was carried out using either bacterial or eukaryotic cells in in vitro culture. After affinity chromatography purification, the performance of both recombinant products was compared by ELISA in similar trials. Our results showed that eukaryotic RBD increased the sensitivity of the assay. Interestingly, our results also support a correlation of the eukaryotic RBD-based ELISA with other assays aimed to test for neutralizing antibodies, which suggests that it provides an indication of protective immunity against SARS-CoV-2.

The BTB-Kelch protein KLHL3 is a Cullin3-dependent E3 ligase that mediates the ubiquitin-dependent degradation of kinases WNK1-4 to control blood pressure and cell volume. A crystal structure of KLHL3 has defined its binding to an acidic degron motif containing a PXXP sequence that is strictly conserved in WNK1, WNK2 and WNK4. Mutations in the second proline abrograte the interaction causing the hypertension syndrome pseudohypoaldosteronism type II. WNK3 shows a diverged degron motif containing four amino acid substitutions that remove the PXXP motif raising questions as to the mechanism of its binding. To understand this atypical interaction, we determined the crystal structure of the KLHL3 Kelch domain in complex with a WNK3 peptide. The electron density enabled the complete 11-mer WNK-family degron motif to be traced for the first time revealing several conserved features not captured in previous work, including additional salt bridge and hydrogen bond interactions. Overall, the WNK3 peptide adopted a conserved binding pose except for a subtle shift to accommodate bulkier amino acid substitutions at the binding interface. At the centre, the second proline was substituted by WNK3 Thr541, providing a unique phosphorylatable residue among the WNK-family degrons. Fluorescence polarisation and structural modelling experiments revealed that its phosphorylation would abrogate the KLHL3 interaction similarly to hypertension-causing mutations. Together, these data reveal how the KLHL3 Kelch domain can accommodate the binding of multiple WNK isoforms and highlight a potential regulatory mechanism for the recruitment of WNK3., (© 2022 The Author(s).)

Background: Early post-liver transplant (LT) acute kidney injury (AKI) has been associated with worse short-term and long-term outcomes, but the incidence and risk factors in our population are unknown., Methods: We designed a prospective, singlecenter, longitudinal cohort study to determine the incidence of AKI during the immediate postoperative period of LT, and to identify the risk factors associated with AKI after LT. Pre-operative and intraoperative variables were analyzed to determine if there was any correlation with the development of post-operative AKI., Results: Eighty-six patients were included in the final analysis; from them, 45 (52%) developed AKI in the following 30 days after LT. The presence of hepatic encephalopathy prior to LT was the factor most strongly associated with the development of AKI (Relative Risk 3.67, 95% Confidence Interval 1.08-8.95). Other factors associated with AKI development were male gender and a higher serum lactate during surgery., Conclusion: AKI was a frequent complication that significantly worsened the prognosis of LT recipients and was associated with an increased 30-day mortality rate. The presence of hepatic encephalopathy strongly predicted the development of severe AKI.

We demonstrated that serpinA3c/k relocates from the cytoplasm to the apical tubular membrane (ATM) in chronic kidney disease (CKD), suggesting its secretion in luminal space in pathophysiological contexts. Here, we studied serpinA3c/k expression and secretion under different stressful conditions in vitro and in vivo. HEK-293 cells were transfected with a FLAG-tagged serpinA3c/k clone and exposed to H 2 O 2 or starvation. Both stressors induced serpinA3c/k secretion but with a higher molecular weight. Glycanase treatment established that serpinA3c/k is glycosylated. Site-directed mutagenesis for each of the four glycosylation sites was performed. During cellular stress, serpinA3c/k secretion increased with each mutant except in the quadruple mutant. In rats and patients suffering acute kidney injury (AKI), an atypical urinary serpinA3c/k excretion (uSerpinA3c/k) was observed. In rats with AKI, the greater the induced kidney damage, the greater the uSerpinA3 c/k, together with relocation toward ATM. Our findings show that: (1) serpinA3c/k is glycosylated and secreted, (2) serpinA3c/k secretion increases during cellular stress, (3) its appearance in urine reveals a pathophysiological state, and (4) urinary serpinA3 excretion could become a potential biomarker for AKI., (© 2022 Federation of American Societies for Experimental Biology.)

Epidemiological and clinical observations have shown that potassium ingestion is inversely correlated with arterial hypertension prevalence and cardiovascular mortality. The higher the dietary potassium, the lower the blood pressure and mortality. This phenomenon is explained, at least in part, by the interaction between salt reabsorption in the distal convoluted tubule (DCT) and potassium secretion in the connecting tubule/collecting duct of the mammalian nephron: In order to achieve adequate K + secretion levels under certain conditions, salt reabsorption in the DCT must be reduced. Because salt handling by the kidney constitutes the basis for the long-term regulation of blood pressure, losing salt prevents hypertension. Here, we discuss how the study of inherited diseases in which salt reabsorption in the DCT is affected has revealed the molecular players, including membrane transporters and channels, kinases, and ubiquitin ligases that form the potassium sensing mechanism of the DCT and the processes through which the consequent adjustments in salt reabsorption are achieved., (© 2021 The Authors. Published under the terms of the CC BY 4.0 license.)

Herbal products are now considered among the most important sources of phenolic compounds: the FINNOVER project aimed at the creation and development of sustainable supply chains to extract and use natural biologically active agents. Vitis vinifera is one of the most utilised herbal products derived from buds and sprouts as polyphenolic food supplements for its homeostatic and astringent properties. This research was aimed to describe the antioxidant capacity and the phytochemical composition of V. vinifera herbal products by the application of spectroscopic and chromatographic fingerprints considering phenolics as potential markers to significantly differentiate traditional preparations (macerates) from innovative extracts obtained by an ultrasound extraction from V. vinifera buds. Two different commercial products were also considered. Flavonols were the most abundant class in ultrasound extracts (45%), while phenolic acids were the most important class in traditional macerates (49%) and commercial bud-preparations (about 50%). This study may support the potential use of V. vinifera bud-products (starting from pruning byproducts) as food supplements to integrate human diet with good amounts of phenolics. Finally, the use of different extraction methods on the same plant material could be an important development to produce innovative herbal products with a phytochemical composition similar to traditional preparations.

Hypertension (HTN) and chronic kidney disease (CKD) are increasingly recognized in pediatric patients and represent risk factors for cardiovascular morbidity and mortality later in life. In CKD, enhanced tubular sodium reabsorption is a leading cause of HTN due to augmented extracellular fluid volume expansion. The renin-angiotensin-aldosterone system (RAAS) upregulates various tubular sodium cotransporters that are also targets of the hormone fibroblast growth factor 23 (FGF23) and its co-receptor Klotho. FGF23 inhibits the activation of 1,25-dihydroxyvitamin D that is a potent suppressor of renin biosynthesis. Here we review the complex interactions and disturbances of the FGF23-Klotho axis, vitamin D, and the RAAS relevant to blood pressure regulation and discuss the therapeutic strategies aimed at mitigating their pathophysiologic contributions to HTN., (© 2020. IPNA.)

Background: Patients with inherited haemorrhagic disorders may bleed during surgery. No questionnaire on bleeding diathesis has been yet validated for the preoperative period and current guidelines provide conflicting recommendations., Aim: We aimed to assess if preoperative assessment with ISTH-BAT (International Society on Thrombosis and Haemostasis Bleeding Assesment Tool) and laboratory screening tests is useful to identify mild previously undiagnosed bleeding disorders (BDs) and to predict bleeding complications in selected patients undergoing elective surgery., Methods: Consecutive patients undergoing elective surgery received ISTH-BAT evaluation and laboratory screening for platelet count, Prothrombin Time (PT) and activated Partial Thromboplastin Time (aPTT). Subjects with an abnormal ISTH-BAT and/or laboratory results underwent further testing, and they were compared with a 1:1 random gender-, age- and type of surgery- matched control group., Results: Overall, 1502 consecutive surgical patients (1186 adults, 316 children) were enrolled. Of these, 83 (5.5%, 95% confidence interval 4.4-6.8) patients (37 adults and 46 children) had an abnormal ISTH-BAT, and/or prolonged PT and/or prolonged aPTT and/or low platelet count; of them, one subject had low von Willebrand factor level, three Factor XII deficiency and four anticardiolipin and/or antiB2GPI antibodies. No major bleeding was reported in these 83 patients and their controls., Conclusion: ISTH-BAT and laboratory screening tests do not accurately detect mild BDs in selected patients undergoing elective surgery., (© 2021 John Wiley & Sons Ltd.)

SIRT7 is a NAD + -dependent deacetylase that controls important aspects of metabolism, cancer, and bone formation. However, the molecular targets and functions of SIRT7 in the kidney are currently unknown. In silico analysis of kidney transcripts of the BXD murine genetic reference population revealed a positive correlation between Sirt7 and Slc12a7 mRNA expression, suggesting a link between the corresponding proteins that these transcripts encode, SIRT7, and the K-Cl cotransporter KCC4, respectively. Here, we find that protein levels and activity of heterologously expressed KCC4 are significantly modulated depending on its acetylation status in Xenopus laevis oocytes. Moreover, SIRT7 interacts with KCC4 in a NAD + -dependent manner and increases its stability and activity in HEK293 cells. Interestingly, metabolic acidosis increases SIRT7 expression in kidney, as occurs with KCC4. In contrast, total SIRT7-deficient mice present lower KCC4 expression and an exacerbated metabolic acidosis than wild-type mice during an ammonium chloride challenge. Altogether, our data suggest that SIRT7 interacts with, stabilizes and modulates KCC4 activity through deacetylation, and reveals a novel role for SIRT7 in renal physiology., (© 2021 The Authors.)

The physiological role of the shorter isoform of with no lysine kinase (WNK)1 that is exclusively expressed in the kidney (KS-WNK1), with particular abundance in the distal convoluted tubule, remains elusive. KS-WNK1, despite lacking the kinase domain, is nevertheless capable of stimulating the NaCl cotransporter, apparently through activation of WNK4. It has recently been shown that a less severe form of familial hyperkalemic hypertension featuring only hyperkalemia is caused by missense mutations in the WNK1 acidic domain that preferentially affect cullin 3 (CUL3)-Kelch-like protein 3 (KLHL3) E3-induced degradation of KS-WNK1 rather than that of full-length WNK1. Here, we show that full-length WNK1 is indeed less impacted by the CUL3-KLHL3 E3 ligase complex compared with KS-WNK1. We demonstrated that the unique 30-amino acid NH 2 -terminal fragment of KS-WNK1 is essential for its activating effect on the NaCl cotransporter and recognition by KLHL3. We identified specific amino acid residues in this region critical for the functional effect of KS-WNK1 and KLHL3 sensitivity. To further explore this, we generated KLHL3-R528H knockin mice that mimic human mutations causing familial hyperkalemic hypertension. These mice revealed that the KLHL3 mutation specifically increased expression of KS-WNK1 in the kidney. We also observed that in wild-type mice, the expression of KS-WNK1 was only detectable after exposure to a low-K + diet. These findings provide new insights into the regulation and function of KS-WNK1 by the CUL3-KLHL3 complex in the distal convoluted tubule and indicate that this pathway is regulated by dietary K + levels. NEW & NOTEWORTHY In this work, we demonstrated that the kidney-specific isoform of with no lysine kinase 1 (KS-WNK1) in the kidney is modulated by dietary K + and activity of the ubiquitin ligase protein Kelch-like protein 3. We analyzed the role of different amino acid residues of KS-WNK1 in its activity against the NaCl cotransporter and sensitivity to Kelch-like protein 3.

Chronic hypoxia is a major contributor to Chronic Kidney Disease (CKD) after Acute Kidney Injury (AKI). However, the temporal relation between the acute insult and maladaptive renal response to hypoxia remains unclear. In this study, we analyzed the time-course of renal hemodynamics, oxidative stress, inflammation, and fibrosis, as well as epigenetic modifications, with focus on HIF1α/VEGF signaling, in the AKI to CKD transition. Sham-operated, right nephrectomy (UNx), and UNx plus renal ischemia (IR + UNx) groups of rats were included and studied at 1, 2, 3, or 4 months. The IR + UNx group developed CKD characterized by progressive proteinuria, renal dysfunction, tubular proliferation, and fibrosis. At first month post-ischemia, there was a twofold significant increase in oxidative stress and reduction in global DNA methylation that was maintained throughout the study. Hif1α and Vegfa expression were depressed in the first and second-months post-ischemia, and then Hif1α but not Vegfa expression was recovered. Interestingly, hypermethylation of the Vegfa promoter gene at the HIF1α binding site was found, since early stages of the CKD progression. Our findings suggest that renal hypoperfusion, inefficient hypoxic response, increased oxidative stress, DNA hypomethylation, and, Vegfa promoter gene hypermethylation at HIF1α binding site, are early determinants of AKI-to-CKD transition.

Extracellular vesicles (EVs) are implicated in the crosstalk between adipocytes and other metabolic organs, and an altered biological cargo has been observed in EVs from human obese adipose tissue (AT). Yet, the role of adipocyte-derived EVs in pancreatic β cells remains to be determined. Here, we explored the effects of EVs released from adipocytes isolated from both rodents and humans and human AT explants on survival and function of pancreatic β cells and human pancreatic islets. EVs from healthy 3T3-L1 adipocytes increased survival and proliferation and promoted insulin secretion in INS-1E β cells and human pancreatic islets, both those untreated or exposed to cytokines or glucolipotoxicity, whereas EVs from inflamed adipocytes caused β cell death and dysfunction. Human lean adipocyte-derived EVs produced similar beneficial effects, whereas EVs from obese AT explants were harmful for human EndoC-βH3 β cells. We observed differential expression of miRNAs in EVs from healthy and inflamed adipocytes, as well as alteration in signaling pathways and expression of β cell genes, adipokines, and cytokines in recipient β cells. These in vitro results suggest that, depending on the physiopathological state of AT, adipocyte-derived EVs may influence β cell fate and function.

With no lysine kinase-4 (WNK4) belongs to a serine-threonine kinase family characterized by the atypical positioning of its catalytic lysine. Despite the fact that WNK4 has been found in many tissues, the majority of its study has revolved around its function in the kidney, specifically as a positive regulator of the thiazide-sensitive NaCl cotransporter (NCC) in the distal convoluted tubule of the nephron. This is explained by the description of gain-of-function mutations in the gene encoding WNK4 that causes familial hyperkalemic hypertension. This disease is mainly driven by increased downstream activation of the Ste20/SPS1-related proline-alanine-rich kinase/oxidative stress responsive kinase-1-NCC pathway, which increases salt reabsorption in the distal convoluted tubule and indirectly impairs renal K + secretion. Here, we review the large volume of information that has accumulated about different aspects of WNK4 function. We first review the knowledge on WNK4 structure and enumerate the functional domains and motifs that have been characterized. Then, we discuss WNK4 physiological functions based on the information obtained from in vitro studies and from a diverse set of genetically modified mouse models with altered WNK4 function. We then review in vitro and in vivo evidence on the different levels of regulation of WNK4. Finally, we go through the evidence that has suggested how different physiological conditions act through WNK4 to modulate NCC activity.

The Revista de Investigación Clínica (RIC) was established in 1948. It has been published continuously for 73 years. Until 2009, it was the journal of the Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán (formerly Hospital de Enfermedades de la Nutrición, and later named Instituto Nacional de la Nutrición), and thereafter it became the official journal of the Mexican National Institutes of Health. The history of this journal may be divided into four eras or periods, each distinctly characterized by the trends, and particular editorial policies imposed by the Editor-in-Chief and Editorial Committee in turn. The RIC, since 2015 known as RIC -Clinical and Translational Investigation-, is currently a nationally and internationally recognized scientific journal. This article briefly reviews the most outstanding historical features of the RIC since its foundation., (Copyright: © 2021 Permanyer.)

I was the Editor-in-Chief of the Revista de Investigación Clínica (RIC) from December 1999-May 2014. In this article, I present a review about how I initiated my experience in the RIC as an author, how I became the Editor-in-Chief, the philosophy of the RIC during my time, the type of publications we had and the citations these papers have received today, the special issues and consensus we published and how the RIC became the official publication of the Mexican Institutes of Health., (Copyright: © 2021 Permanyer.)

Introduction: Optimal method for noninvasive assessment of venous congestion remains an unresolved issue. Portal vein (PV) and intrarenal venous flow alterations are markers of abdominal venous congestion and have been associated with acute kidney injury (AKI) in cardiac surgery patients. It is currently unknown if portal vein flow (PVF) alterations in heart failure can be reversed with diuretic treatment and track decongestion., Objective: The aim of this study is to evaluate PVF alterations in patients with ADHF at arrival and after decongestive treatment., Methods: Assessment of venous congestion using point-of-care ultrasound was performed in 12 patients with ADHF (6 patients with left-sided heart failure and 6 patients with right-sided heart failure). Evaluation included inferior vena cava (IVC) size and collapsibility in addition to PV Doppler to determine pulsatility fraction (PF)., Results: Increased PV PF (81.75 ± 13%) was found on admission. After effective decongestive treatment, it improved to (17.43 ± 2.2%). Improvement in IVC size and collapsibility was seen in most patients with left-sided heart failure and none of the patients with right-sided heart failure. Improvement in PV PF coincided with return to baseline of Serum Cr in patients that presented with AKI., Conclusions: Evaluation of abdominal venous congestion by point-of-care ultrasound could aid in diagnosis and follow-up of patients with congestive kidney injury., (© 2021 S. Karger AG, Basel.)

Gain-of-function mutations in with no lysine (K) 1 (WNK1) and WNK4 genes are responsible for familial hyperkalemic hypertension (FHHt), a rare, inherited disorder characterized by arterial hypertension and hyperkalemia with metabolic acidosis. More recently, FHHt-causing mutations in the Kelch-like 3-Cullin 3 (KLHL3-CUL3) E3 ubiquitin ligase complex have shed light on the importance of WNK's cellular degradation on renal ion transport. Using full exome sequencing for a 4-generation family and then targeted sequencing in other suspected cases, we have identified new missense variants in the WNK1 gene clustering in the short conserved acidic motif known to interact with the KLHL3-CUL3 ubiquitin complex. Affected subjects had an early onset of a hyperkalemic hyperchloremic phenotype, but normal blood pressure values"Functional experiments in Xenopus laevis oocytes and HEK293T cells demonstrated that these mutations strongly decrease the ubiquitination of the kidney-specific isoform KS-WNK1 by the KLHL3-CUL3 complex rather than the long ubiquitous catalytically active L-WNK1 isoform. A corresponding CRISPR/Cas9 engineered mouse model recapitulated both the clinical and biological phenotypes. Renal investigations showed increased activation of the Ste20 proline alanine-rich kinase-Na+-Cl- cotransporter (SPAK-NCC) phosphorylation cascade, associated with impaired ROMK apical expression in the distal part of the renal tubule. Together, these new WNK1 genetic variants highlight the importance of the KS-WNK1 isoform abundance on potassium homeostasis.

New technology development and globalisation have led to extreme changes in the agri-food sector in recent years that need an important food supply chain characterisation from plant materials to commercial productions. Many analytical strategies are commonly utilised in the agri-food industry, often using complementary technologies with different purposes. Chromatography on-line coupled to mass spectrometry (MS) is one of the most selective and sensitive analytical methodologies. The purpose of this overview is to present the most recent MS-based techniques applied to food analysis. An entire section is dedicated to the recent applications of high-resolution MS. Covered topics include liquid (LC)- and gas chromatography (GC)-MS analysis of natural bioactive substances, including carbohydrates, flavonoids and related compounds, lipids, phenolic compounds, vitamins, and other different molecules in foodstuffs from the perspectives of food composition, food authenticity and food adulteration. The results represent an important contribution to the utilisation of GC-MS and LC-MS in the field of natural bioactive compound identification and quantification.

The role of Cl - as an intracellular signaling ion has been increasingly recognized in recent years. One of the currently best described roles of Cl - in signaling is the modulation of the With-No-Lysine (K) (WNK) - STE20-Proline Alanine rich Kinase (SPAK)/Oxidative Stress Responsive Kinase 1 (OSR1) - Cation-Coupled Cl - Cotransporters (CCCs) cascade. Binding of a Cl - anion to the active site of WNK kinases directly modulates their activity, promoting their inhibition. WNK activation due to Cl - release from the binding site leads to phosphorylation and activation of SPAK/OSR1, which in turn phosphorylate the CCCs. Phosphorylation by WNKs-SPAK/OSR1 of the Na + -driven CCCs (mediating ions influx) promote their activation, whereas that of the K + -driven CCCs (mediating ions efflux) promote their inhibition. This results in net Cl - influx and feedback inhibition of WNK kinases. A wide variety of alterations to this pathway have been recognized as the cause of several human diseases, with manifestations in different systems. The understanding of WNK kinases as Cl - sensitive proteins has allowed us to better understand the mechanistic details of regulatory processes involved in diverse physiological phenomena that are reviewed here. These include cell volume regulation, potassium sensing and intracellular signaling in the renal distal convoluted tubule, and regulation of the neuronal response to the neurotransmitter GABA., (Copyright © 2020 Murillo-de-Ozores, Chávez-Canales, de los Heros, Gamba and Castañeda-Bueno.)

Malignant pleural mesothelioma (MPM) is a rare and aggressive tumor, often associated with exposure to asbestos and characterized by poor prognosis and limited treatment options. The biologically active form of vitamin D, calcitriol, exerts anticancer effects in many cell types, both alone and in combination with chemotherapy drugs, through binding to vitamin D receptor (VDR); however, the role of calcitriol in MPM is still unknown. This study aimed to determine the potential antitumor role of calcitriol in MPM. The results showed that calcitriol reduces cell viability and proliferation in human MPM cells lines, which express both cytoplasmic and nuclear VDR; furthermore, calcitriol potentiated the inhibitory activity of the chemotherapy drug PEM. These effects were paralleled by cell cycle arrest and inhibition in expression of c-Myc and cyclins involved in cell cycle progression. Exposure of MPM cells to calcitriol also produced an alteration in mitochondrial function and inhibition in the expression of respiratory chain complex subunits. Finally, the inhibitory effects of calcitriol were also observed on viability of human primary MPM cells. Collectively, these results indicate a novel anticancer role for calcitriol in MPM, suggesting potential for vitamin D derivatives, alone or in combination with chemotherapy, in the treatment of this malignancy., (Copyright © 2020 Gesmundo, Silvagno, Banfi, Monica, Fanciulli, Gamba, Congiusta, Libener, Riganti, Ghigo and Granata.)

The objective of this study was to investigate the status of COVID-19 patients with sudden anosmia and dysgeusia using an olfactory dysfunction questionnaire highlighting recovery times. This prospective study included 75 patients who completed a patient-reported outcome questionnaire. Among these, 46 patients completed an olfactory evaluation based on the duration of anosmia and dysgeusia. The olfactory evaluation revealed that 24% (N = 18) of patients had mild hyposmia, 13% (N = 10) had moderate hyposmia, 30% (N = 23) had severe hyposmia, 32% (N = 24) had anosmia, and 100% had dysgeusia (N = 75). The viral load significantly decreased throughout the 17 days following the onset of the olfactory disorder. The purpose of this study was to understand whether patients with COVID-19 can recover olfactory and gustatory function, in contrast to patients with other rhinoviruses and inflammatory diseases such as rhinosinusitis chronic and rhinosinusitis with polyps. These preliminary clinical findings indicate that the relatively rapid recovery of olfactory and gustative function can mean a resolution of viral infection in most patients. The present study suggests that coronavirus can induce olfactory dysfunction but not permanent damage. Olfactory and gustatory functional impairment has been recognized as a hallmark of COVID-19 and may be an important predictor of clinical outcome. Our study supports the need to add anosmia and dysgeusia to the list of symptoms used in screening tools for possible COVID-19 infection., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)