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Up‐regulation of P‐glycoprotein expression by glutathione depletion‐induced oxidative stress in rat brain microvessel endothelial cells
Author(s) -
Hong Hao,
Lu Ying,
Ji ZhaoNing,
Liu GuoQing
Publication year - 2006
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.2006.03993.x
Subject(s) - glutathione , buthionine sulfoximine , microvessel , oxidative stress , intracellular , rhodamine 123 , p glycoprotein , chemistry , blood–brain barrier , reactive oxygen species , endothelial stem cell , biochemistry , biology , endocrinology , immunology , in vitro , central nervous system , antibiotics , immunohistochemistry , multiple drug resistance , enzyme
Glutathione (GSH) depletion has been implicated in the pathogenesis of neurological diseases. During GSH depletion, cells of the blood–brain barrier (BBB) are subjected to chronic oxidative stress. In this study, we investigated the effect of such stress, produced with the GSH synthesis inhibitor l ‐buthionine‐(S,R)‐sulfoximine (BSO), on expression of P‐glycoprotein (Pgp) in primary cultured rat brain microvessel endothelial cells that comprise the blood–brain barrier (BBB). Application of BSO to cell monolayers at concentrations up to 800 µ m caused increases in expression of Pgp. Concentrations ≥ 400 µ m BSO decreased cell viability. Application of 200 µ m BSO caused a significant increase in Pgp function activity, as assessed by rhodamine 123 (Rh123) accumulation experiments. At this concentration, BSO produced time‐dependent decreases in levels of intracellular GSH and increases in levels of intracellular reactive oxygen species (iROS). The increases were also observed within 48 h following BSO treatment in mdr1a and mdr1b mRNA. Exposure of cells to BSO for 24 h produced maximal effects in the accumulation of iROS, and in expression and function of Pgp. The ROS scavenger N ‐acetylcysteine prevented ROS generation and attenuated the changes of both expression and activity of Pgp induced by BSO. Therefore, the transport of Pgp substrates may be affected by changing Pgp expression under conditions of chronic oxidative stress induced by GSH depletion.