Phagocytosis of IgG-coated erythrocytes (EIgG) can depress several macrophage functions. Our previous studies have suggested that this macrophage dysfunction may be due to an oxidative stress caused by the interaction of hemoglobin-derived iron with superoxide and/or hydrogen peroxide. Since lysosomotropic agents are capable of altering iron handling by macrophages, the present study evaluated the ability of these agents to prevent the macrophage dysfunction and lipid peroxidation caused by a phagocytic challenge with EIgG. Elicited rat peritoneal macrophages showed a depression of PMA-stimulated hydrogen peroxide production, calcium ionophore-stimulated arachidonate release and Fc receptor-mediated phagocytosis. The lysosomotropic agents; chloroquine, quinacrine, ammonium chloride and methylamine all prevented the depression of hydrogen peroxide production and arachidonate release but did not alter the depression of phagocytic function. These agents also prevented the increase in lipid peroxidation products caused by a phagocytic challenge with EIgG. These results suggest that the ability of lysosomotropic agents to prevent some aspects of macrophage dysfunction after a phagocytic challenge may be due to their ability to block the oxidative stress caused by the challenge.
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http://dx.doi.org/10.1023/a:1027386206458 | DOI Listing |
Virology
January 2025
Institute of Immunology, Philipps-Universität Marburg, 35043, Marburg, Germany; CSL Innovation GmbH, Emil-von-Behring, Straße 76, 35041, Marburg, Germany.
Cationic lysosomotropic molecules such as ammonium salts and chloroquine inhibit influenza A virus (IAV) infection in cell culture by counteracting endosomal acidification and hampering viral-endosomal fusion. Here, we studied the effects of storage of L-glutamine-supplemented cell culture media on accumulation of ammonium and inhibition of IAV infection. The storage-related inhibitory effect was observed for DMEM and OptiMEM media but not for RPMI medium, and was more pronounced for IAV with pH-stable hemagglutinin.
View Article and Find Full Text PDFEur J Med Chem
December 2024
Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, 226-8501, Japan; School of Life Science and Technology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, 226-8501, Japan. Electronic address:
We have discovered lysosomotropic autophagy inhibitors from our compound library of sp-rich diazatricycloundecane skeletons. Compound 1u was identified as the most potent biological activity for LC3-II protein accumulation through the structure-activity relationships (SARs) for LC3-II protein accumulation and anti-proliferative activity at the three freely available substituents (R-R) in the diazatricycloundecane skeleton. Compound 1u inhibited lysosome-dependent degradation without affecting autophagosome formation.
View Article and Find Full Text PDFToxicol In Vitro
December 2024
College of Animal Science and Technology, Yangtze University, Jingzhou 434025, Hubei, China. Electronic address:
Chloroquine (CQ) is widely used in the therapy against malarial, tumor and recently the COVID-19 pandemic, as a lysosomotropic agent to inhibit the endolysosomal trafficking in the autophagy pathway. We previously reported that CQ (20 μM, 36 h) could reprogram transcriptome, and impair multiple signaling pathways vital to porcine immature Sertoli cells (iSCs). However, whether CQ treatment could affect the metabolomic compositions of porcine iSCs remains unclear.
View Article and Find Full Text PDFChem Sci
August 2024
Centre for Cancer Cell Biology and Drug Discovery, Griffith University Nathan Brisbane 4111 Queensland Australia
Innovative -acridine thiosemicarbazones (NATs) were designed along with their iron(iii), copper(ii), and zinc(ii) complexes. Lysosomal targeting was promoted by specifically incorporating the lysosomotropic Pgp substrate, acridine, into the thiosemicarbazone scaffold to maintain the tridentate N, N, S-donor system. The acridine moiety enables a significant advance in thiosemicarbazone design, since: (1) it enables tracking of the drugs by confocal microscopy using its inherent fluorescence; (2) it is lysosomotropic enabling lysosomal targeting; and (3) as acridine is a P-glycoprotein (Pgp) substrate, it facilitates lysosomal targeting, resulting in the drug overcoming Pgp-mediated resistance.
View Article and Find Full Text PDFACS Sens
August 2024
Department of Chemistry, Yonsei University, Seoul 03722, Republic of Korea.
Owing to the biological significance of Cl in cells, several chemical fluorescent probes and biosensors have been constructed to monitor this anion in the cytosol and subcellular organelles. However, a fluorescent probe for the selective detection of nuclear Cl has not been described thus far. In the current study, we developed the first nuclear Cl-selective biosensor, Cl-YFP-NLS, whose fluorescence was effectively quenched by this anion, and demonstrated that it is an efficient and powerful tool for determining the levels of nuclear Cl.
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