Effects of PCBs (Arocolor 1254) on cytochrome-P450 expression and monooxygenase activities in cultured foetal rat hepatocytes

Roelandt, L.; Todaro, Anna; Thomé, Jean-Pierre; Kremers, Pierre

doi:10.1016/0300-483x(94)02972-w

Cited by 7 publications

(1 citation statement)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1) suggests the existence of a T–cell–independent component in the inflammation induced by litreol. Due the severe impairment of the TCR rearrangement [23, 24]in these mice, this innate inflammation could be mediated by NK cells [25]and/or by the oxidative metabolic stress generated by litreol which, as other xenobiotics, can be a potent generator of free radicals [26, 27, 28, 29]. In this direction, recent data from our group indicate that urushiols are potent inhibitors of mitochondrial respiration suggesting a potential xenobiotic–like behavior for litreol [submitted].…”

Section: Discussionmentioning

confidence: 99%

CD8+ T Cells Are the Effectors of the Contact Dermatitis Induced by Urushiol in Mice and Are Regulated by CD4+ T Cells

López

Kalergis

Becker

et al. 1998

Int Arch Allergy Immunol

View full text Add to dashboard Cite

Background: The exposure of human skin to leaves and branches of litre (Lithraea caustica), a Chilean endemic tree, induces a severe contact dermatitis characterized by swelling and pruritus in susceptible individuals. The allergenic priniciple of litre is 3–pentadecyl (10–enyl) catechol (litreol), which is structurally similar to the allergens isolated from poison oak and poison ivy. All of them belong to a family of compounds named urushiols. As a proelectrophilic allergen, litreol must be intracellularly activated before modifying proteins of individuals exposed to it. As a result, self–peptides derived from litreol–modified intracellular proteins would be presented in the context of class I MHC molecules. We hypothesized that CD8+ T lymphocytes would play a major role during the effector phase of the immune response induced by those modified peptides. In order to test this hypothesis, we investigated the cellular immune response to litreol in Balb/cJ mice. The role of the different lymphocyte subpopulations in this response was assessed by immunodepleting mice of CD4+ or CD8+ T lymphocytes using specific monoclonal antibodies (mAbs). We report the observation that the contact dermatitis induced by litreol has two components: a primary response which does not require TCRαβ+ T cells, and a secondary response mediated mainly by CD8+ T cells and regulated by CD4+ T cells. Our results show that CD8+ lymphocytes play a central role as effectors of the secondary response to litreol. Furthermore, our data suggest that two functionally different CD4+ T subpopulations serve as regulators of the CD8+ T cell function: a CD4+ T helper population sensitive to a low dose of the depleting mAb, and CD4+ T suppressor population which is eliminated only with a high dose of depleting mAb.

show abstract

Section: Discussionmentioning

confidence: 99%

CD8+ T Cells Are the Effectors of the Contact Dermatitis Induced by Urushiol in Mice and Are Regulated by CD4+ T Cells

López

Kalergis

Becker

et al. 1998

Int Arch Allergy Immunol

View full text Add to dashboard Cite

show abstract

Influence of aroclor 1254 on benzo(a)pyrene‐induced DNA breakage, oxidative DNA damage, and cytochrome P4501A activity in human hepatoma cell line

Yuan

Zou

et al. 2008

Environmental Toxicology

View full text Add to dashboard Cite

Both polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) are important environmental pollutants. They coexist widely in the environment at very low levels. Numerous studies indicated that aroclor1254 (one of PCBs mixture) is the inducer of cytochrome P450 1A enzyme acitivity. Benzo(a)pyrene (BaP) can cause a variety of toxicities in vitro, such as oxidative DNA damage and genotoxicity. In the present study, HepG2 cells were treated with either BaP (50 microM) or aroclor1254 at concentrations of 11.5 (low), 23.0 (medium), and 46.0 microM (high) alone, or pretreated the cells with aroclor1254 (11.5, 23.0, and 46.0 microM), followed by BaP (50 microM). It was found that 7-ethoxyresorufin-O-deetylase (EROD) activities of HepG2 cells exposed to either BaP or aroclor 1254 increased. DNA damage measured by DNA migration and the formation of 8-hydroxy-2'-deoxyguanosine (8-OHdG) also increased in cells exposed to BaP, but not in cells exposed to aroclor1254. Under the Aroclor 1254 pretreatment condition, BaP-induced EROD activities was enhanced in cells exposed to the medium and high concentrations of aroclor1254 (P < 0.01 for both), whereas in all pretreatment groups aroclor1254 significantly increased BaP-induced DNA migration (P < 0.01 for all) and the 8-OHdG formation (P < 0.05 for all). In addition, there was positive correlation between the EROD induction activity and Olive tail moment (r(2) = 0.958, P < 0.01) or the levels of 8-OHdG (r(2) = 0.992, P < 0.01). The findings suggest that under the experimental conditions aroclor1254 may enhance BaP-induced DNA migration and oxidative DNA damage in HepG2, due to inducing CYP1A enzyme activity.

show abstract

Diorthosubstituted Polychlorinated Biphenyls in Caudate Nucleus in Parkinson's Disease

Corrigan

Murray²,

Wyatt³

et al. 1998

Experimental Neurology

170

105

View full text Add to dashboard Cite

Effects of PCBs (Arocolor 1254) on cytochrome-P450 expression and monooxygenase activities in cultured foetal rat hepatocytes

Cited by 7 publications

References 19 publications

CD8+ T Cells Are the Effectors of the Contact Dermatitis Induced by Urushiol in Mice and Are Regulated by CD4+ T Cells

CD8+ T Cells Are the Effectors of the Contact Dermatitis Induced by Urushiol in Mice and Are Regulated by CD4+ T Cells

Influence of aroclor 1254 on benzo(a)pyrene‐induced DNA breakage, oxidative DNA damage, and cytochrome P4501A activity in human hepatoma cell line

Diorthosubstituted Polychlorinated Biphenyls in Caudate Nucleus in Parkinson's Disease

Contact Info

Product

Resources

About