Cassagnes L. E. auteur aut IRD Perio Pierre auteur aut IRD Ferry G. auteur aut IRD Moulharat N. auteur aut IRD Antoine M. auteur aut IRD Gayon R. auteur aut IRD Boutin J. A. auteur aut IRD Nepveu F. auteur aut IRD Reybier K. auteur aut IRD text journalArticle eng text/pdf born digital access Quinones are highly reactive molecules that readily undergo either one- or two-electron reduction. One-electron reduction of quinones or their derivatives by enzymes such as cytochrome P450 reductase or other flavoproteins generates unstable semiquinones, which undergo redox cycling in the presence of molecular oxygen leading to the formation of highly reactive oxygen species. Quinone reductases 1 and 2 (QR1 and QR2) catalyze the two-electron reduction of quinones to form hydroquinones, which can be removed from the cell by conjugation of the hydroxyl with glucuronide or sulfate thus avoiding its autoxidation and the formation of free radicals and highly reactive oxygen species. This characteristic confers a detoxifying enzyme role to QR1 and QR2, even if this character is strongly linked to the excretion capacity of the cell. Using [PR spectroscopy and confocal microscopy we demonstrated that the amount of reactive oxygen species (ROS) produced by Chinese hamster ovary (CHO) cells overexpressing QR1 or QR2 compared to naive CHO cells was determined by the quinone structural type indeed, whereas the amount of ROS produced in the cell was strongly decreased with para-quirmues such as menadione in the presence of quinone reductase 1 or 2, a strong increase in ROS was recorded with ortho -quinones such as adrenochrome, aminochrome, dopachrome, or 3,5-di-tert-butyl-o-benzoquinone in cells overexpressing QR, especially QR2. These differences could originate from the excretion process, which is different for para- and ortho-quinones. These results are of particular interest in the case of dopamine considering the association of QR2 with various neurological disorders such as Parkinson disease. specialized Quinone reductase NQO1 NQO2 Ortho-quinones Para-quinones EPR Reactive oxygen species Oxidative stress Free radicals 020 050 89 126-134 2015 0891-5849 https://www.documentation.ird.fr/hor/fdi:010066009 10.1016/j.freeradbiomed.2015.07.150 0891-5849 [F B010066009] https://www.documentation.ird.fr/hor/fdi:010066009 https://www.documentation.ird.fr/intranet/publi/2016/01/010066009.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2016-02-02 2017-08-23 fdi:010066009 fre