Cellular determinants involving mitochondrial dysfunction, oxidative stress and apoptosis correlate with the synergic cytotoxicity of epigallocatechin-3-gallate and menadione in human leukemia Jurkat T cells. (January 2016)

• Record Type: Journal Article
• Authors: Tofolean, Ioana Teodora; Ganea, Constanta; Ionescu, Diana; Filippi, Alexandru; Garaiman, Alexandru; Goicea, Alexandru; Gaman, Mihnea-Alexandru; Dimancea, Alexandru; Baran, Irina
• Is Part Of: Pharmacological research. Volume 103(2016:Jan.)
• Page Start: 300
• Page End: 317
• Publication Date: 2016-01
• Subjects: Epigallocatechin-3-gallate (PubChem CID: 65064) -- Menadione sodium bisulfite (PubChem CID: 23665888) -- Cyclosporin A (PubChem CID: 5284373) -- Antimycin A (PubChem CID: 14957) -- Rotenone (PubChem CID: 6758); 7-AAD 7-Aminoactinomycin D -- AM antimycin A -- CM-H2DCFDA 5-(and-6)-chloromethyl-2′, 7′-dichlorodihydrofluorescein diacetate, acetyl ester -- CsA cyclosporin A -- DIG digitonin -- DMSO dimethyl sulfoxide -- DNP 2, 4-dinitrophenol -- EGCG epigallocatechin-3-gallate -- FITC fluorescein isothiocyanate -- JC-1 5, 5′, 6, 6′-tetrachloro-1, 1′, 3, 3′-tetraethylbenzimidazolocarbo-cyanine iodide -- MD menadione (2-methyl-1, 4-naphthoquinone) -- mPTP mitochondrial permeability transition pore -- NADH reduced nicotinamide adenine dinucleotide -- NADPH reduced nicotinamide adenine dinucleotide phosphate -- PBS phosphate buffer saline -- PI propidium iodide -- ROS reactive oxygen species -- ROT rotenone -- SS standard saline solution -- TriX Triton X-100; Epigallocatechin-3-gallate -- Menadione -- Apoptosis -- Mitochondrial dysfunction -- Oxidative stress -- Leukemia; Pharmacology -- Periodicals; Pharmacology -- Periodicals; Research -- Periodicals; Médicaments -- Recherche -- Périodiques; Pharmacologie -- Périodiques; 615.105
• DOI: 10.1016/j.phrs.2015.12.013
• Languages: English
• ISSNs: 1043-6618

Abstract

Graphical abstract: Epigallocatechin-3-gallate and menadione at clinically relevant parameters (treatment time 6–48 h, dosage 10 μM EGCG, 10 μM MD) display synergic cytotoxic activities that robustly correlate with depletion of the mitochondrial Ca 2+ pool, Δ ψ m collapse, inhibition of mitochondrial respiration, oxidative stress and apoptosis induction in human leukemia Jurkat T cells. Abstract: We have investigated the growth-suppressive action of epigallocatechin-3-gallate (EGCG) on human leukemia Jurkat T cells. Results show a strong correlation between the dose-dependent reduction of clonogenic survival following acute EGCG treatments and the EGCG-induced decline of the mitochondrial level of Ca 2+ . The cell killing ability of EGCG was synergistically enhanced by menadione. In addition, the cytotoxic effect of EGCG applied alone or in combination with menadione was accompanied by apoptosis induction. We also observed that in acute treatments EGCG displays strong antioxidant properties in the intracellular milieu, but concurrently triggers some oxidative stress generating mechanisms that can fully develop on a longer timescale. In parallel, EGCG dose-dependently induced mitochondrial depolarization during exposure, but this condition was subsequently reversed to a persistent hyperpolarized mitochondrial state that was dependent on the activity of respiratory Complex I. Fluorimetric measurements suggest that EGCG is a mitochondrial Complex III inhibitor and indicate that EGCG evokes a specific cellular fluorescence with emission at 400 nm and two main excitation bands (at 330 nm and 350 nm) that may originate from a mitochondrial supercomplex containing dimeric Complex III and dimeric ATP-synthase, and therefore could provide a valuable means to characterize the functional properties of the respiratory chain.