title: eEF-2 Phosphorylation Down-Regulates P-Glycoprotein Over-Expression in Rat Brain Microvessel Endothelial Cells.
abstract: OBJECTIVE
  We investigated whether glutamate, NMDA receptors, and eukaryote elongation factor-2 kinase (eEF-2K)/eEF-2 regulate P-glycoprotein expression, and the effects of the eEF-2K inhibitor NH125 on the expression of P-glycoprotein in rat brain microvessel endothelial cells (RBMECs).
  
  
  METHODS
  Cortex was obtained from newborn Wistar rat brains. After surface vessels and meninges were removed, the pellet containing microvessels was resuspended and incubated at 37°C in culture medium. Cell viability was assessed by the MTT assay. RBMECs were identified by immunohistochemistry with anti-vWF. P-glycoprotein, phospho-eEF-2, and eEF-2 expression were determined by western blot analysis. Mdr1a gene expression was analyzed by RT-PCR.
  
  
  RESULTS
  Mdr1a mRNA, P-glycoprotein and phospho-eEF-2 expression increased in L-glutamate stimulated RBMECs. P-glycoprotein and phospho-eEF-2 expression were down-regulated after NH125 treatment in L-glutamate stimulated RBMECs.
  
  
  CONCLUSIONS
  eEF-2K/eEF-2 should have played an important role in the regulation of P-glycoprotein expression in RBMECs. eEF-2K inhibitor NH125 could serve as an efficacious anti-multidrug resistant agent.
authors.affiliation: Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: Xing Hua
authors.initials: XH
authors.lastname: Tang
authors.affiliation: Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: Xun Yi
authors.initials: XY
authors.lastname: Wu
authors.affiliation: Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: Lan
authors.initials: L
authors.lastname: Xu
authors.affiliation: Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: You Xin
authors.initials: YX
authors.lastname: Fang
authors.affiliation: Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Wang
authors.affiliation: Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: Guo Xing
authors.initials: GX
authors.lastname: Zhu
authors.affiliation: Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Hong
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000098:blood supply; D002478:Cells, Cultured; D015536:Down-Regulation; D054736:Elongation Factor 2 Kinase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D042783:Endothelial Cells / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism*; D055806:Microvessels / Q000166:cytology; D010766:Phosphorylation; D051381:Rats; D017208:Rats, Wistar
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D054736:Elongation Factor 2 Kinase