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Journal of Experimental & Clinical... Sep 2023Malignant ascites commonly occurs in advanced or recurrent stages of epithelial ovarian cancer during peritoneal carcinomatosis and is correlated with poor prognosis....
BACKGROUND
Malignant ascites commonly occurs in advanced or recurrent stages of epithelial ovarian cancer during peritoneal carcinomatosis and is correlated with poor prognosis. Due to its complex composition of cellular and acellular components malignant ascites creates a unique tumor microenvironment, which mediates immunosuppression and promotes progression of disease. However, the immunosuppressive mechanisms remain poorly understood.
METHODS
In the present study, we explored the antitumor activity of healthy donor NK and T cells directed against ovarian cancer cells in presence of malignant ascites derived from patients with advanced or recurrent peritoneal carcinomatosis. A wide range of methods was used to study the effect of ascites on NK and T cells (FACS, ELISA, EliSpot, qPCR, Live-cell and confocal microscopy, Western blot and electrolyte flux assays). The ascites components were assessed using quantitative analysis (nephelometry, potentiometry and clinical chemistry) and separation methods (dialysis, ultracentrifugal filtration and lipid depletion).
RESULTS
Ascites rapidly inhibited NK cell degranulation, tumor lysis, cytokine secretion and calcium signaling. Similarly, target independent NK and T cell activation was impaired in ascites environment. We identified imbalanced electrolytes in ascites as crucial factors causing extensive immunosuppression of NK and T cells. Specifically, high sodium, low chloride and low potassium content significantly suppressed NK-mediated cytotoxicity. Electrolyte imbalance led to changes in transcription and protein expression of electrolyte channels and impaired NK and T cell activation. Selected inhibitors of sodium electrolyte channels restored intracellular calcium flux, conjugation, degranulation and transcript expression of signaling molecules. The levels of ascites-mediated immunosuppression and sodium/chloride/potassium imbalance correlated with poor patient outcome and selected molecular alterations were confirmed in immune cells from ovarian cancer patients.
CONCLUSION
Our data suggest a novel electrolyte-based mechanism of immunosuppression in malignant ascites of patients with peritoneal carcinomatosis. We show for the first time that the immunosuppression of NK cytotoxicity in coculture assays is correlated to patient poor survival. Therapeutic application of sodium channel inhibitors may provide new means for restoring immune cell activity in ascites or similar electrolyte imbalanced environments.
Topics: Humans; Female; Peritoneal Neoplasms; Ascites; Chlorides; T-Lymphocytes; Ovarian Neoplasms; Potassium; Tumor Microenvironment
PubMed: 37684704
DOI: 10.1186/s13046-023-02798-8 -
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 -
Protein Science : a Publication of the... Oct 2023The SARS-CoV-2 envelope (E) protein forms a five-helix bundle in lipid bilayers whose cation-conducting activity is associated with the inflammatory response and...
The SARS-CoV-2 envelope (E) protein forms a five-helix bundle in lipid bilayers whose cation-conducting activity is associated with the inflammatory response and respiratory distress symptoms of COVID-19. E channel activity is inhibited by the drug 5-(N,N-hexamethylene) amiloride (HMA). However, the binding site of HMA in E has not been determined. Here we use solid-state NMR to measure distances between HMA and the E transmembrane domain (ETM) in lipid bilayers. C, N-labeled HMA is combined with fluorinated or C-labeled ETM. Conversely, fluorinated HMA is combined with C, N-labeled ETM. These orthogonal isotopic labeling patterns allow us to conduct dipolar recoupling NMR experiments to determine the HMA binding stoichiometry to ETM as well as HMA-protein distances. We find that HMA binds ETM with a stoichiometry of one drug per pentamer. Unexpectedly, the bound HMA is not centrally located within the channel pore, but lies on the lipid-facing surface in the middle of the TM domain. This result suggests that HMA may inhibit the E channel activity by interfering with the gating function of an aromatic network. These distance data are obtained under much lower drug concentrations than in previous chemical shift perturbation data, which showed the largest perturbation for N-terminal residues. This difference suggests that HMA has higher affinity for the protein-lipid interface than the channel pore. These results give insight into the inhibition mechanism of HMA for SARS-CoV-2 E.
Topics: Humans; Amiloride; SARS-CoV-2; Lipid Bilayers; COVID-19
PubMed: 37632140
DOI: 10.1002/pro.4755 -
Frontiers in Veterinary Science 2023The antiviral activity of different mutagens against single-stranded RNA viruses is well documented; however, their activity on the replication of double-stranded RNA...
INTRODUCTION
The antiviral activity of different mutagens against single-stranded RNA viruses is well documented; however, their activity on the replication of double-stranded RNA viruses remains unexplored. This study aims to investigate the effect of different antivirals on the replication of a chicken embryo fibroblast-adapted Infectious Bursal Disease virus, FVSKG2. This study further explores the antiviral mechanism utilized by the most effective anti-IBDV agent.
METHODS
The cytotoxicity and anti-FVSKG2 activity of different antiviral agents (ribavirin, 5-fluorouracil, 5-azacytidine, and amiloride) were evaluated. The virus was serially passaged in chicken embryo fibroblasts 11 times at sub-cytotoxic concentrations of ribavirin, 5-fluorouracil or amiloride. Further, the possible mutagenic and non-mutagenic mechanisms utilized by the most effective anti-FVSKG2 agent were explored.
RESULTS AND DISCUSSION
Ribavirin was the least cytotoxic on chicken embryo fibroblasts, followed by 5-fluorouracil, amiloride and 5-azacytidine. Ribavirin inhibited the replication of FVSKG2 in chicken embryo fibroblasts significantly at concentrations as low as 0.05 mM. The extinction of FVSKG2 was achieved during serial passage of the virus in chicken embryo fibroblasts at ≥0.05 mM ribavirin; however, the emergence of a mutagen-resistant virus was not observed until the eleventh passage. Further, no mutation was observed in 1,898 nucleotides of the FVSKG2 following its five passages in chicken embryo fibroblasts in the presence of 0.025 mM ribavirin. Ribavarin inhibited the FVSKG2 replication in chicken embryo fibroblasts primarily through IMPDH-mediated depletion of the Guanosine Triphosphate pool of cells. However, other mechanisms like ribavirin-mediated cytokine induction or possible inhibition of viral RNA-dependent RNA polymerase through its interaction with the enzyme's active sites enhance the anti-IBDV effect. Ribavirin inhibits ds- RNA viruses, likely through IMPDH inhibition and not mutagenesis. The inhibitory effect may, however, be augmented by other non-mutagenic mechanisms, like induction of antiviral cytokines in chicken embryo fibroblasts or interaction of ribavirin with the active sites of RNA-dependent RNA polymerase of the virus.
PubMed: 37601760
DOI: 10.3389/fvets.2023.1192583 -
BMC Chemistry Aug 2023Cardiovascular disorders are among the leading causes of death worldwide, especially hypertension, a silent killer syndrome requiring multiple drug therapy for...
Sustainable chromatographic quantitation of multi-antihypertensive medications: application on diverse combinations containing hydrochlorothiazide along with LC-MS/MS profiling of potential impurities: greenness and whiteness evaluation.
Cardiovascular disorders are among the leading causes of death worldwide, especially hypertension, a silent killer syndrome requiring multiple drug therapy for appropriate management. Hydrochlorothiazide is an extensively utilized thiazide diuretic that combines with several antihypertensive drugs for effective treatment of hypertension. In this study, sustainable, innovative and accurate high performance liquid chromatographic methods with diode array and tandem mass detectors (HPLC-DAD and LC-MS/MS) were developed, optimized and validated for the concurrent determination of Hydrochlorothiazide (HCT) along with five antihypertensive drugs, namely; Valsartan (VAL), Amlodipine besylate (AML), Atenolol (ATN), Amiloride hydrochloride (AMI), and Candesartan cilextil (CAN) in their diverse pharmaceutical dosage forms and in the presence of Chlorothiazide (CT) and Salamide (DSA) as HCT officially identified impurities. The HPLC-DAD separation was achieved utilizing Inertsil ODS-3 C column (250 × 4.6 mm, 5 μm) attached with photodiode array detection at 225.0 nm. Gradient elution was performed utilizing a mixture of solvent A (20.0 mM potassium dihydrogen phosphate, pH 3.0 ± 0.2, adjusted with phosphoric acid) and solvent B (acetonitrile) at ambient temperature. Linearity ranges were 0.1-100.0 µg/mL for HCT, VAL, AML and CAN, 0.05 -100.0 µg/mL for both ATN and AMI and 0.05-8.0 µg/mL for both CT and DSA. Additionally, this work describes the use of liquid chromatography-electrospray-tandem mass spectrometry for the accurate detection and quantification of the impurities; CT and DSA in the negative mode utilizing triple quadrupole mass spectrometry. The linearity ranges for those impurities were 1.0-200.0 ng/mL and 5.0-200.0 ng/mL for CT and DSA, respectively. Developed methods' validation was achieved in accordance with International Conference on Harmonization (ICH) guidelines. Upon applying liquid chromatographic techniques for the drug analysis, a green and sustainable assessment have to be handled due to the consumption of energy and many solvents. Through the use of the HEXAGON, Analytical Greenness (AGREE) and White Analytical Chemistry (WAC) tools, greenness and sustainability have been statistically assessed. The optimized HPLC-DAD and LC-MS/MS methods were fast, accurate, precise, and sensitive, and consequently could be applied for conventional analysis and quality control of the proposed drugs in their miscellaneous dosage forms for the purpose of reducing laboratory wastes, time of the analysis time, effort, and cost.
PubMed: 37598182
DOI: 10.1186/s13065-023-01015-z -
Histochemistry and Cell Biology Nov 2023Urinary bladder cancer can be treated by intravesical application of therapeutic agents, but the specific targeting of cancer urothelial cells and the endocytotic...
Urinary bladder cancer can be treated by intravesical application of therapeutic agents, but the specific targeting of cancer urothelial cells and the endocytotic pathways of the agents are not known. During carcinogenesis, the superficial urothelial cells exhibit changes in sugar residues on the apical plasma membranes. This can be exploited for selective targeting from the luminal side of the bladder. Here we show that the plant lectins Jacalin (from Artocarpus integrifolia), ACA (from Amaranthus caudatus) and DSA (from Datura stramonium) selectively bind to the apical plasma membrane of low- (RT4) and high-grade (T24) cancer urothelial cells in vitro and urothelial tumours ex vivo. The amount of lectin binding was significantly different between RT4 and T24 cells. Endocytosis of lectins was observed only in cancer urothelial cells and not in normal urothelial cells. Transmission electron microscopy analysis showed macropinosomes, endosome-like vesicles and multivesicular bodies filled with lectins in RT4 and T24 cells and also in cells of urothelial tumours ex vivo. Endocytosis of Jacalin and ACA in cancer cells was decreased in vitro after addition of inhibitor of macropinocytosis 5-(N-ethyl-N-isopropyl) amiloride (EIPA) and increased after stimulation of macropinocytosis with epidermal growth factor (EGF). Clathrin, caveolin and flotillin did not colocalise with lectins. These results confirm that the predominant mechanism of lectin endocytosis in cancer urothelial cells is macropinocytosis. Therefore, we propose that lectins in combination with conjugated therapeutic agents are promising tools for improved intravesical therapy by targeting cancer cells.
Topics: Humans; Lectins; Urinary Bladder Neoplasms; Endocytosis; Urinary Bladder; Endosomes; Plant Lectins
PubMed: 37535087
DOI: 10.1007/s00418-023-02224-2 -
Pharmaceuticals (Basel, Switzerland) Jul 2023Rheumatoid arthritis is an inflammatory disease, and pyroptosis is a form of death associated with an inflammatory response. Pyroptosis, which occurs in synovial and... (Review)
Review
Rheumatoid arthritis is an inflammatory disease, and pyroptosis is a form of death associated with an inflammatory response. Pyroptosis, which occurs in synovial and osteoblastic cells, can exacerbate the development of rheumatoid arthritis. The inhibition of pyroptosis of these cells can, therefore, clearly be used as a therapeutic strategy against rheumatoid arthritis. Here, we have summarized the current status of progress in the treatment of rheumatoid arthritis by targeting cellular pyroptosis. We have identified seven compounds, including a cyclic RNA, a microRNA, a peptide, and a cytokine (protein), that may influence the progression of rheumatoid arthritis by regulating the initiation of pyroptosis. All of these compounds have been shown to have anti-rheumatoid effects in vitro and/or in vivo and have the potential to be developed as anti-rheumatoid agents. These findings may help to accelerate the development of anti-rheumatoid arthritis drugs.
PubMed: 37513864
DOI: 10.3390/ph16070952 -
Frontiers in Cellular Neuroscience 2023Tissue acidification causes sustained activation of primary nociceptors, which causes pain. In mammals, acid-sensing ion channels (ASICs) are the primary acid sensors;...
Tissue acidification causes sustained activation of primary nociceptors, which causes pain. In mammals, acid-sensing ion channels (ASICs) are the primary acid sensors; however, Na/H exchangers (NHEs) and TRPV1 receptors also contribute to tissue acidification sensing. ASICs, NHEs, and TRPV1 receptors are found to be expressed in nociceptive nerve fibers. ASIC inhibitors reduce peripheral acid-induced hyperalgesia and suppress inflammatory pain. Also, it was shown that pharmacological inhibition of NHE1 promotes nociceptive behavior in acute pain models, whereas inhibition of TRPV1 receptors gives relief. The murine skin-nerve preparation was used in this study to assess the activation of native polymodal nociceptors by mild acidification (pH 6.1). We have found that diminazene, a well-known antagonist of ASICs did not suppress pH-induced activation of CMH-fibers at concentrations as high as 25 μM. Moreover, at 100 μM, it induces the potentiation of the fibers' response to acidic pH. At the same time, this concentration virtually completely inhibited ASIC currents in mouse dorsal root ganglia (DRG) neurons (IC = 17.0 ± 4.5 μM). Non-selective ASICs and NHEs inhibitor EIPA (5-(N-ethyl-N-isopropyl)amiloride) at 10 μM, as well as selective NHE1 inhibitor zoniporide at 0.5 μM induced qualitatively the same effects as 100 μM of diminazene. Our results indicate that excitation of afferent nerve terminals induced by mild acidification occurs mainly due to the NHE1, rather than acid-sensing ion channels. At high concentrations, diminazene acts as a weak blocker of the NHE. It lacks chemical similarity with amiloride, EIPA, and zoniporide, so it may represent a novel structural motif for the development of NHE antagonists. However, the effect of diminazene on the acid-induced excitation of primary nociceptors remains enigmatic and requires additional investigations.
PubMed: 37502464
DOI: 10.3389/fncel.2023.1131661 -
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