Superoxide induces cellular growth and apoptosis of cultured human peripheral blood lymphocytes
Main Article Content
Keywords
Superoxides, Cell Proliferation, Apoptosis, Lymphocytes
Abstract
Background: Mild oxidative stress induces the cells to proliferate. On the other hand, too much oxidative stress may cause cells to die or suffer irreversible damage. Cancer and β-cells destruction on diabetes can illustrate the paradoxical roles of superoxide in the physiological cellular responses.
Methods: the activation of resting human peripheral blood lymphocytes (HPBL) was done using different mitogens such as phytohemagglutinin (PHA), concanavalin A (ConA), and phorbol ester (PMA), as well the superoxide producing system, paraquat. The physiological responses were evaluated in terms of proliferation using MTT to assess activation of the resting cells, as well apoptosis and necrosis by fluorescent microscopy.
Results: our results show that the increase in oxidative status by superoxide in resting human peripheral blood lymphocytes induces cells to proliferate; however, higher concentrations of superoxide are harmful, inducing apoptosis and necrosis.
Conclusions: our results clearly show the involvement of superoxide (supplied by paraquat and/or induced with mitogens) in physiological responses such as proliferation and apoptosis. Such divergent responses should be explained in terms of our dose-response observations.
References
Seve M, Favier A, Osman M, Hernández D, Vaitaitis G, Flores NC, McCord JM, Flores SC. The human immunodeficiency virus-1 Tat protein increases cell proliferation, alters sensitivity to zinc chelator-induced apoptosis, and changes Sp1 DNA binding in HeLa cells. Arch Biochem Biophys 1999; 361:165-172.
Hernández-Saavedra D, McCord JM. Paradoxical effects of thiol reagents on Jurkat cells and a new thiol-sensitive form of human mitochondrial superoxide dismutasa. Cancer Res 2003; 63:159-163.
Janssen YMW, Vanhouten B, Borm PJA, Mossman BT. Cell and tissue responses to oxidative damage. Lab Invest 1993; 69:261-274.
McCord JM. Superoxide radical: controversies, contradictions, and paradoxes. Proc Soc Exp Biol Med 1995; 209:112-117.
Mosmann T. Rapid colorimetric assay for cellular growth and survival: application to proliferation and cytotoxicity assays. J Immunol Methods 1983; 65(1-2):55-63.
Loveland BE, Johns TG, Mackay IR, Vaillant F, Wang ZX, Hertzog PJ. Validation of the MTT dye assay for enumeration of cells in proliferative and antiproliferative assays. Biochem Int 1992; 27(3):501-510.
Melinn M, McLaughlin H. Nitroblue tetrazolium reduction in lymphocytes. J Leukoc Biol 1987; 41:325-329.
Schreck R, Rieber P, Baeuerle PA. Reactive oxygen intermediates as apparently widely used messengers in the activation of the NF-kappa β transcription factor and HIV-1. EMBO J 1991; 10:2247-2258.
Tatla S, Woodhead V, Foreman JC, Chain BM. The role of reactive oxygen species in triggering proliferation and IL-2 secretion in T cells. Free Radic Biol Med 1999; 26:14-24.
Khan MA, Jeremy JY, Hallinan T, Tateson JE, Hoffbrand AV, Wickremasinghe RG. Antioxidants impair the coupling of cell-surface ligand receptors to the inositol lipid signalling pathway in human T lymphocytes but not in Jurkat T lymphoblastic leukemia cells. Evidence that leukotrienes are not involved in the coupling mechanism. Biochim Biophys Acta 1993; 1178:215-220.
Richter C. Pro-oxidants and mitochondrial Ca2+: their relationship to apoptosis and oncogenesis. FEBS Lett 1993; 325:104-107.
Buttke TM, Sandstrom PA. Oxidative stress as a me-diator of apoptosis. Immunol. Today 1994; 15:7-10.
Lennon SV, Martin SJ, Cotter TG. Dose-dependent induction of apoptosis in human tumour cell lines by widely diverging stimuli. Cell Prolif 1991; 24:203-214.
Bazar LS, Deeg HJ. Ultraviolet B-induced DNA fragmentation (apoptosis) in activated T-lymphocytes and Jurkat cells is augmented by inhibition of RNA and protein synthesis. Exp Hematol 1992; 20:80-86.