Unlabelled: The goal of the study was to estimate the effect of a selective V-type H -ATPase inhibitor bafilomycin A1 and nicotinic acid adenine dinucleotide phosphate (NAADP) on energetic processes in NK/Ly cell by directly measuring the respiration of isolated mitochondria and ATPase activities. NAADP (7 μM) increased the activity of Na /K -ATPase in the postmitochondrial fraction of NK/Ly cells, but lower concentration of NAADP decreased it (0.1 and 1 μM). The increase the activity of plasma membrane Ca ATPase (PMCA) under NAADP application (1 and 7 μM) was observed. However, NAADP (1 μM) decreased activities of sarcoendoplasmic reticulum Ca -ATPase (SERCA) and basal Mg -ATPase. Bafilomycin A1 (1 μM) increased the activity of Na /K -ATPase and potentiated the effect of NAADP (1 μM) on this pump. At the same time, bafilomycin A1 (1 μM) completely prevented all effects of NAADP (1 μM) on activities of PMCA, SERCA, and basal Mg -ATPase, confirming that these effects are dependent on acidic stores. Bafilomycin A1 or NAADP decreased respiratory and oxidative phosphorylation rates in NK/Ly mitochondria when α-ketoglutarate was used as substrate in contrast to succinate. Thus, α-ketoglutarate oxidation is more sensitive to bafilomycin A1 and NAADP influences compared with succinate oxidation. However, bafilomycin A1 + NAADP and any of these compounds separately lead to full uncoupling of mitochondria after ADP addition irrespectively to substrate used. Bafilomycin A1 affects isolated tumor mitochondria more effectively in combination with NAADP. Bafilomycin and NAADP alter some membrane-associated ATPases and inhibit respiration in mitochondria of the Nemeth-Kellner lymphoma.
Significance Of Research Paragraph: Bafilomycin A1 potentiates the effect of NAADP by inhibiting the mitochondrial energetic process in lymphoma cells and activity of Na /K -ATPase. The obtained data show promising possibility to use bafilomycin A1 and NAADP as chemotherapeutic agents for lymphoma cells treatment. This is important because lymphomas are seventh most common form of cancer. Today the lymphoma mortality is 15% to 30%, whereas the effectiveness of malignant neoplasms treatment is less than 50%.
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http://dx.doi.org/10.1002/cbf.3231 | DOI Listing |
Int J Mol Sci
January 2024
Department of Experimental Biology, Faculty of Science, Masaryk University, 625 00 Brno, Czech Republic.
Bafilomycin A1 inhibits V-type H ATPases on the molecular level, which acidifies endo-lysosomes. The main objective of the study was to assess the effect of bafilomycin A1 on Ca content, NAADP-induced Ca release, and ATPase activity in rat hepatocytes and human colon cancer samples. Chlortetracycline (CTC) was used for a quantitative measure of stored calcium in permeabilized rat hepatocytes.
View Article and Find Full Text PDFLife Sci
June 2023
Faculty of Pharmacy, Department of Pharmacology, Hacettepe University, Ankara, Turkey.
Front Cell Dev Biol
March 2022
Laboratory of General Physiology, Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia, Pavia, Italy.
Nicotinic acid adenine dinucleotide phosphate (NAADP) is a newly discovered second messenger that gates two pore channels 1 (TPC1) and 2 (TPC2) to elicit endo-lysosomal (EL) Ca release. NAADP-induced lysosomal Ca release may be amplified by the endoplasmic reticulum (ER) through the Ca-induced Ca release (CICR) mechanism. NAADP-induced intracellular Ca signals were shown to modulate a growing number of functions in the cardiovascular system, but their occurrence and role in cardiac mesenchymal stromal cells (C-MSCs) is still unknown.
View Article and Find Full Text PDFJ Cell Sci
March 2021
Department of Cell and Developmental Biology, UCL, London WC1E 6BT, UK
Lysosomes are acidic Ca stores often mobilised in conjunction with endoplasmic reticulum (ER) Ca stores. Glycyl-L-phenylalanine 2-naphthylamide (GPN) is a widely used lysosomotropic agent that evokes cytosolic Ca signals in many cells. However, whether these signals are the result of a primary action on lysosomes is unclear in light of recent evidence showing that GPN mediates direct ER Ca release through changes in cytosolic pH.
View Article and Find Full Text PDFJ Cell Sci
July 2020
Division of Life Science and State Key Laboratory for Molecular Neuroscience, The Hong Kong University of Science and Technology, Hong Kong, China
The role of two-pore channel type 2 (TPC2, encoded by )-mediated Ca release was recently characterized in zebrafish during establishment of the early spinal circuitry, one of the key events in the coordination of neuromuscular activity. Here, we extend our study to investigate the role of TPC2 in the regulation of caudal primary motor neuron (CaP) axon extension. We used a combination of TPC2 knockdown with a translation-blocking morpholino antisense oligonucleotide (MO), TPC2 knockout via the generation of a mutant line of zebrafish using CRISPR/Cas9 gene-editing and pharmacological inhibition of TPC2 via incubation with bafilomycin A1 (an H-ATPase inhibitor) or -ned-19 (an NAADP receptor antagonist), and showed that these treatments attenuated CaP Ca signaling and inhibited axon extension.
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