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Overexpression of heme oxygenase‐1 (HO‐1) in V79 cells results in increased resistance to hyperbaric oxygen (HBO)‐induced DNA damage
Author(s) -
Rothfuss Andreas,
Speit Günter
Publication year - 2002
Publication title -
environmental and molecular mutagenesis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1
H-Index - 87
eISSN - 1098-2280
pISSN - 0893-6692
DOI - 10.1002/em.10120
Subject(s) - heme oxygenase , dna damage , oxidative stress , biliverdin , heme , comet assay , transfection , microbiology and biotechnology , reactive oxygen species , chinese hamster , cell culture , biology , dna , chemistry , biochemistry , genetics , enzyme
Heme oxygenase (HO) catalyzes the rate‐limiting step in the oxidative degradation of heme to biliverdin. The isoform HO‐1 is inducible by a variety of agents causing oxidative stress and has been suggested to play an important role in cellular protection against oxidant‐mediated cell damage. Using treatment of cell cultures with hyperbaric oxygen (HBO) as a model for oxidative stress, we have shown an induction of HO‐1 in isolated human lymphocytes after a single HBO exposure and protection of these cells against DNA damage by subsequent oxidative stress. In contrast, V79 Chinese hamster cells showed neither a comparable adaptive protection nor an induction of HO‐1 after HBO exposure, which makes this cell line an attractive model system for a further characterization of HO‐1‐mediated protection. In the present study, we investigated whether overexpression of HO‐1 renders V79 cells more resistant to DNA damage induced by HBO. Transient transfection of V79 cells with a full‐length human HO‐1 cDNA resulted in a 2–3‐fold increase in HO‐1 protein levels. Comet assay experiments with and without FPG posttreatment for the determination of oxidative DNA base damage showed that HO‐1 overexpressing V79 cells were significantly protected against oxidative DNA damage induced by a single HBO exposure. Furthermore, HO‐1‐transfected cells exhibited a clearly reduced induction of micronulei after HBO treatment. Since the observed protective effects were abolished by cotreatment with the HO‐1 inhibitor tin‐mesoporphyrin, our study suggests that a low‐level overexpression of HO‐1 provides protection against oxidative DNA damage induced by HBO. Environ. Mol. Mutagen. 40:258–265, 2002. © 2002 Wiley‐Liss, Inc.