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Frontiers in Cellular and Infection... 2023Fungal infections have become an increasing threat as a result of growing numbers of susceptible hosts and diminishing effectiveness of antifungal drugs due to...
Fungal infections have become an increasing threat as a result of growing numbers of susceptible hosts and diminishing effectiveness of antifungal drugs due to multi-drug resistance. This reality underscores the need to develop novel drugs with unique mechanisms of action. We recently identified 5-(,-hexamethylene)amiloride (HMA), an inhibitor of human Na/H exchanger isoform 1, as a promising scaffold for antifungal drug development. In this work, we carried out susceptibility testing of 45 6-substituted HMA and amiloride analogs against a panel of pathogenic fungi. A series of 6-(2-benzofuran)amiloride and HMA analogs that showed up to a 16-fold increase in activity against were identified. Hits from these series showed broad-spectrum activity against both basidiomycete and ascomycete fungal pathogens, including multidrug-resistant clinical isolates.
Topics: Humans; Amiloride; Antifungal Agents; Fungi; Mycoses; Microbial Sensitivity Tests; Cryptococcus neoformans
PubMed: 36923593
DOI: 10.3389/fcimb.2023.1101568 -
Nature Communications Sep 2023The reaction of CO with HO to form bicarbonate (HCO) and H controls sperm motility and fertilization via HCO-stimulated cAMP synthesis. A complex network of signaling...
The reaction of CO with HO to form bicarbonate (HCO) and H controls sperm motility and fertilization via HCO-stimulated cAMP synthesis. A complex network of signaling proteins participates in this reaction. Here, we identify key players that regulate intracellular pH (pH) and HCO in human sperm by quantitative mass spectrometry (MS) and kinetic patch-clamp fluorometry. The resting pH is set by amiloride-sensitive Na/H exchange. The sperm-specific putative Na/H exchanger SLC9C1, unlike its sea urchin homologue, is not gated by voltage or cAMP. Transporters and channels implied in HCO transport are not detected, and may be present at copy numbers < 10 molecules/sperm cell. Instead, HCO is produced by diffusion of CO into cells and readjustment of the CO/HCO/H equilibrium. The proton channel H1 may serve as a unidirectional valve that blunts the acidification ensuing from HCO synthesis. This work provides a new framework for the study of male infertility.
Topics: Humans; Male; Bicarbonates; Carbon Dioxide; Semen; Sperm Motility; Spermatozoa; Hydrogen-Ion Concentration
PubMed: 37669933
DOI: 10.1038/s41467-023-40855-0 -
Experimental and Therapeutic Medicine Jul 2021Nephrogenic diabetes insipidus (NDI) is characterized by impaired urinary concentrating ability, despite normal or elevated plasma concentrations of the antidiuretic... (Review)
Review
Nephrogenic diabetes insipidus (NDI) is characterized by impaired urinary concentrating ability, despite normal or elevated plasma concentrations of the antidiuretic hormone, arginine vasopressin (AVP). NDI can be inherited or acquired. NDI can result from genetic abnormalities, such as mutations in the vasopressin V2 receptor () or the aquaporin-2 (AQP2) water channel, or acquired causes, such as chronic lithium therapy. Congenital NDI is a rare condition. Mutations in are responsible for approximately 90% of patients with congenital NDI, and they have an X-linked pattern of inheritance. In approximately 10% of patients, congenital NDI has an autosomal recessive or dominant pattern of inheritance with mutations in the gene. In 2% of cases, the genetic cause is unknown. The main symptoms at presentation include growth retardation, vomiting or feeding concerns, polyuria plus polydipsia, and dehydration. Without treatment, most patients fail to grow normally, and present with associated constipation, urological complication, megacystis, trabeculated bladder, hydroureter, hydronephrosis, and mental retardation. Treatment of NDI consist of sufficient water intake, low-sodium diet, diuretic thiazide, sometimes in combination with a cyclooxygenase (COX) inhibitor (indomethacin) or nonsteroidal anti-inflammatory drugs (NSAIDs), or hydrochlorothiazide in combination with amiloride. Some authors note a generally favorable long-term outcome and an apparent loss of efficacy of medical treatment during school age.
PubMed: 34055061
DOI: 10.3892/etm.2021.10178 -
The Cochrane Database of Systematic... Jun 2023Hypertonic saline enhances mucociliary clearance and may lessen the destructive inflammatory process in the airways. This is an update of a previously published review. (Review)
Review
BACKGROUND
Hypertonic saline enhances mucociliary clearance and may lessen the destructive inflammatory process in the airways. This is an update of a previously published review.
OBJECTIVES
To investigate efficacy and tolerability of nebulised hypertonic saline treatment in people with cystic fibrosis (CF) compared to placebo or other treatments that enhance mucociliary clearance.
SEARCH METHODS
We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Cystic Fibrosis Trials Register, comprising references identified from comprehensive electronic database searches, handsearches of relevant journals and abstract books of conference proceedings. We also searched ongoing trials databases. Most recent search: 25 April 2022.
SELECTION CRITERIA
We included randomised and quasi-randomised controlled trials assessing hypertonic saline compared to placebo or other mucolytic therapy, for any duration or dose regimen in people with CF (any age or disease severity).
DATA COLLECTION AND ANALYSIS
Two authors independently reviewed all identified trials and data, and assessed trial quality. We assessed the certainty of the evidence using GRADE. For cross-over trials we stipulated a one-week washout period. We planned to use results from a paired analysis in the review, but this was only possible in one trial. For other cross-over trials, we chose to treat the trials as if they were parallel.
MAIN RESULTS
We included 24 trials (1318 participants, aged one month to 56 years); we excluded 29 trials, two trials are ongoing and six are awaiting classification. We judged 15 of the 24 included trials to have a high risk of bias due to participants' ability to discern the taste of the solutions. Hypertonic saline 3% to 7% versus placebo (stable disease) We are uncertain whether the regular use of nebulised hypertonic saline in stable lung disease leads to an improvement in forced expiratory volume in one second (FEV) % predicted at four weeks, (mean difference (MD) 3.30%, 95% confidence interval (CI) 0.71 to 5.89; 4 trials, 246 participants; very low-certainty evidence). In preschool children we found no difference in lung clearance index (LCI) at four weeks, but a small improvement after 48 weeks of treatment with hypertonic saline compared to isotonic saline (MD -0.60, 95% CI -1.00 to -0.19; 2 trials, 192 participants). We are also uncertain whether hypertonic saline made a difference to mucociliary clearance, pulmonary exacerbations or adverse events compared to placebo. Hypertonic saline versus control (acute exacerbation) Two trials compared hypertonic saline to control, but only one provided data. There may be little or no difference in lung function measured by FEV % predicted after hypertonic saline compared to isotonic saline (MD 5.10%, 95% CI -14.67 to 24.87; 1 trial, 130 participants). Neither trial reported any deaths or measures of sputum clearance. There were no serious adverse events. Hypertonic saline versus rhDNase Three trials compared a similar dose of hypertonic saline to recombinant deoxyribonuclease (rhDNase); two trials (61 participants) provided data for inclusion in the review. We are uncertain whether there was an effect of hypertonic saline on FEV % predicted after three weeks (MD 1.60%, 95% CI -7.96 to 11.16; 1 trial, 14 participants; very low-certainty evidence). At three months, rhDNase may lead to a greater increase in FEV % predicted than hypertonic saline (5 mL twice daily) at 12 weeks in participants with moderate to severe lung disease (MD 8.00%, 95% CI 2.00 to 14.00; low-certainty evidence). We are uncertain whether adverse events differed between the two treatments. No deaths were reported. Hypertonic saline versus amiloride One trial (12 participants) compared hypertonic saline to amiloride but did not report on most of our outcomes. The trial found that there was no difference between treatments in measures of sputum clearance (very low-certainty evidence). Hypertonic saline compared with sodium-2-mercaptoethane sulphonate (Mistabron®) One trial (29 participants) compared hypertonic saline to sodium-2-mercaptoethane sulphonate. The trial did not measure our primary outcomes. There was no difference between treatments in any measures of sputum clearance, courses of antibiotics or adverse events (very low-certainty evidence). Hypertonic saline versus mannitol One trial (12 participants) compared hypertonic saline to mannitol, but did not report lung function at relevant time points for this review; there were no differences in sputum clearance, but mannitol was reported to be more 'irritating' (very low-certainty evidence). Hypertonic saline versus xylitol Two trials compared hypertonic saline to xylitol, but we are uncertain whether there is any difference in FEV % predicted or median time to exacerbation between groups (very low-certainty evidence). No other outcomes were reported in the review. Hypertonic saline 7% versus hypertonic saline 3% We are uncertain whether there was an improvement in FEV % predicted after treatment with 7% hypertonic saline compared with 3% (very low-certainty evidence).
AUTHORS' CONCLUSIONS
We are very uncertain if regular use of nebulised hypertonic saline by adults and children over the age of 12 years with CF results in an improvement in lung function after four weeks (three trials; very low-certainty evidence); there was no difference seen at 48 weeks (one trial; low-certainty evidence). Hypertonic saline improved LCI modestly in children under the age of six years. Evidence from one small cross-over trial in children indicates that rhDNase may lead to better lung function than hypertonic saline at three months; qualifying this, we highlight that while the study did demonstrate that the improvement in FEV was greater with daily rhDNase, there were no differences seen in any of the secondary outcomes. Hypertonic saline does appear to be an effective adjunct to physiotherapy during acute exacerbations of lung disease in adults. However, for the outcomes assessed, the certainty of the evidence ranged from very low to low at best, according to the GRADE criteria. The role of hypertonic saline in conjunction with cystic fibrosis transmembrane conductance regulator (CFTR) modulator therapy now needs to be considered, and future research needs to focus on this aspect.
Topics: Adult; Child; Child, Preschool; Humans; Administration, Inhalation; Amiloride; Cystic Fibrosis; Mannitol; Saline Solution, Hypertonic; Sodium; Xylitol; Infant; Adolescent; Young Adult; Middle Aged
PubMed: 37319354
DOI: 10.1002/14651858.CD001506.pub5 -
Journal of Clinical Medicine Jun 2022Multiple sclerosis (MS) is a widely known inflammatory, demyelinating disease of the central nervous system. The pathogenesis of progressive multiple sclerosis (PMS) is... (Review)
Review
Multiple sclerosis (MS) is a widely known inflammatory, demyelinating disease of the central nervous system. The pathogenesis of progressive multiple sclerosis (PMS) is a complex, multi-level process that causes therapeutic difficulties. Along with variables such as age and duration of the disease, pathogenetic mechanisms change from inflammatory to neurodegenerative processes. Therefore, the efficacy of available anti-inflammatory drugs approved for the treatment of PMS, such as ocrelizumab or siponimod, is limited in time. In search of innovative solutions, several research studies have been conducted to evaluate the effectiveness of drugs with neuroprotective or remyelinating effects in PMS, including biotin, ibudilast, simvastatin, alpha-lipoic acid, clemastine, amiloride, fluoxetine, riluzole, masitinib, opicinumab, and lamotrigine. The current review includes those compounds, which have entered the clinical phase of assessment, and the authors discuss future prospects for successful PMS treatment.
PubMed: 35743410
DOI: 10.3390/jcm11123342 -
Cureus May 2023Gitelman syndrome is a rare hereditary tubulopathy characterized by hypokalemic metabolic alkalosis, hypomagnesemia, and hypocalciuria. In this case report, we...
Gitelman syndrome is a rare hereditary tubulopathy characterized by hypokalemic metabolic alkalosis, hypomagnesemia, and hypocalciuria. In this case report, we describe a 21-year-old male who presented with myalgias, asthenia, general muscle weakness, and hypokalemia after receiving oral potassium supplementation for six months. Additional biochemical studies showed hypomagnesemia, metabolic alkalosis, and increased urinary potassium and magnesium excretion. Calcium urinary excretion was within the normal range, but 25-hydroxycholecalciferol levels were low. Systolic arterial hypertension was found, probably reflecting chronic hyperreninemic hyperaldosteronism. Genetic testing for mutations identified a pathogenic variant in homozygosity, which confirmed the Gitelman syndrome diagnosis. Treatment with chronic potassium and magnesium oral supplementation was started, as well as eplerenone and amiloride, with sustained correction of hypokalemia and hypomagnesemia.
PubMed: 37273382
DOI: 10.7759/cureus.38418 -
IScience Jun 2024The kidney is a vital organ responsible for water and sodium metabolism, while the primary function of amiloride is to promote the excretion of water and sodium. We...
The kidney is a vital organ responsible for water and sodium metabolism, while the primary function of amiloride is to promote the excretion of water and sodium. We investigated amiloride enhanced the sunitinib sensitivity in RCC. We found both sunitinib and amiloride displayed cytotoxicity and exerted the synergy effect in RCC cells and arrays. Protein expression profiles were screened via MS/TMT, revealing that FN3K was upregulated in the sunitinib group, and rescued in amiloride and the combination administration. Exogenous FN3K could promote proliferation, invasion and metastasis and decrease the sensitivity of Caki-1 cells to sunitinib, also, exogenous FN3K up-regulated VEGFR2 expression and activated AKT/mTOR signal pathway. More FN3K and VEGFR2 accumulated in R-Caki-1 cells and rescued by amiloride treatment. Co-IP and IF confirmed the interaction between FN3K and VEGFR2. In conclusion, FN3K depletion mediated VEGFR2 disruption promotes amiloride synergized the anti-RCC activity of sunitinib.
PubMed: 38868177
DOI: 10.1016/j.isci.2024.109997 -
Frontiers in Plant Science 2023Macropinocytosis is an endocytic process that plays an important role in animal development and disease occurrence but until now has been rarely reported in organisms...
Macropinocytosis is an endocytic process that plays an important role in animal development and disease occurrence but until now has been rarely reported in organisms with cell walls. We investigated the properties of endocytosis in a red alga, . The cells non-selectively internalized extracellular fluid into large-scale endocytic vesicles (1.94 ± 0.51 μm), and this process could be inhibited by 5-(N-ethyl-N-isopropyl) amiloride, an macropinocytosis inhibitor. Moreover, endocytosis was driven by F-actin, which promotes formation of ruffles and cups from the cell surface and facilitates formation of endocytotic vesicles. After vesicle formation, endocytic vesicles could be acidified and acquire digestive function. These results indicated macropinocytosis in . Abundant phosphatidylinositol kinase and small GTPase encoding genes were found in the genome of this alga, while PI3K, Ras, and Rab5, the important participators of traditional macropinocytosis, seem to be lacked. Such findings provide a new insight into endocytosis in organisms with cell walls and facilitate further research into the core regulatory mechanisms and evolution of macropinocytosis.
PubMed: 37822336
DOI: 10.3389/fpls.2023.1225675 -
Stem Cell Research & Therapy Jul 2023Acute lung injury is characterized by overwhelmingly elevated PAI-1 in both lung edema fluid and the circulating system. The role of increased PAI-1, encoded by Serpine1...
BACKGROUND
Acute lung injury is characterized by overwhelmingly elevated PAI-1 in both lung edema fluid and the circulating system. The role of increased PAI-1, encoded by Serpine1 gene, in the regeneration of injured lung epithelium has not been understood completely. This study aimed to investigate the role of Serpine1 in the regulation of alveolar type 2 epithelial cell (AT2) fate in a humanized mouse line carrying diseased mutants (Serpine1).
METHODS
Wild-type (wt) and Serpine1 AT2 cells were either cultured as monolayers or 3D alveolospheres. Colony-forming assay and total surface area of organoids were analyzed. AT1 and AT2 cells in organoids were counted by immunohistochemistry and fluorescence-activated cell sorting (FACS). To test the potential effects of elevated PAI-1 on the permeability in the epithelial monolayers, we digitized the biophysical properties of polarized AT2 monolayers grown at the air-liquid interface.
RESULTS
A significant reduction in total AT2 cells harvested in Serpine1 mice was observed compared with wt controls. AT2 cells harvested from Serpine1 mice reduced significantly over the wt controls. Spheroids formed by Serpine1 AT2 cells were lesser than wt control. Similarly, the corresponding surface area, a readout of re-alveolarization of injured epithelium, was markedly reduced in Serpine1 organoids. FACS analysis revealed a significant suppression in the number of AT2 cells, in particular, the CD44 subpopulation, in Serpine1 organoids. A lesser ratio of AT1:AT2 cells in Serpine1 organoids was observed compared with wt cultures. There was a significant increase in transepithelial resistance but not amiloride inhibition.
CONCLUSIONS
Our study suggests elevated PAI-1 in injured lungs downregulates alveolar epithelial regeneration by reducing the AT2 self-renewal, particularly in the CD44 cells.
Topics: Mice; Animals; Plasminogen Activator Inhibitor 1; Cells, Cultured; Alveolar Epithelial Cells; Lung; Permeability
PubMed: 37501095
DOI: 10.1186/s13287-023-03414-4 -
Current Opinion in Nephrology and... Sep 2022This review provides an up-to-date understanding about the regulation of epithelial sodium channel (ENaC) expression and function. In particular, we will focus on its... (Review)
Review
PURPOSE OF REVIEW
This review provides an up-to-date understanding about the regulation of epithelial sodium channel (ENaC) expression and function. In particular, we will focus on its implication in renal Na+ and K+ handling and control of blood pressure using transgenic animal models.
RECENT FINDINGS
In kidney, the highly amiloride-sensitive ENaC maintains whole body Na+ homeostasis by modulating Na+ transport via epithelia. This classical role is mostly confirmed using genetically engineered animal models. Recently identified key signaling pathways that regulate ENaC expression and function unveiled some nonclassical and unexpected channel regulatory processes. If aberrant, these dysregulated mechanisms may also result in the development of salt-dependent hypertension.The purpose of this review is to highlight the most recent findings in renal ENaC regulation and function, in considering data obtained from animal models.
SUMMARY
Increased ENaC-mediated Na+ transport is a prerequisite for salt-dependent forms of hypertension. To treat salt-sensitive hypertension it is crucial to fully understand the function and regulation of ENaC.
Topics: Animals; Blood Pressure; Epithelial Sodium Channels; Humans; Hypertension; Mice; Mice, Transgenic; Sodium; Sodium Chloride, Dietary
PubMed: 35894285
DOI: 10.1097/MNH.0000000000000821