Rapid loss of blood-brain barrier P-glycoprotein activity through transporter internalization demonstrated using a novel in situ proteolysis protection assay.

Journal Article (letter;Journal Article)

Blood-brain barrier (BBB) P-glycoprotein activity is rapidly reduced by vascular endothelial growth factor (VEGF) acting via Src and by tumor necrosis factor-alpha acting via protein kinase C (PKC)beta1. To probe underlying mechanism(s), we developed an in vivo, immunoblot-based proteinase K (PK) protection assay to assess the changes in the P-glycoprotein content of the BBB's luminal membrane. Infusion of PK into the brain vasculature selectively cleaved luminal membrane P-glycoprotein, leaving intracellular proteins intact. Intracerebroventricular injection of VEGF partially protected P-glycoprotein from proteolytic cleavage, consistent with transporter internalization. Activation of PKCbeta1 did not protect P-glycoprotein. Thus, VEGF and PKCbeta1 reduce P-glycoprotein activity by distinct mechanisms.

Full Text

Duke Authors

Cited Authors

  • Hawkins, BT; Rigor, RR; Miller, DS

Published Date

  • September 2010

Published In

Volume / Issue

  • 30 / 9

Start / End Page

  • 1593 - 1597

PubMed ID

  • 20628400

Pubmed Central ID

  • PMC2949254

Electronic International Standard Serial Number (EISSN)

  • 1559-7016

International Standard Serial Number (ISSN)

  • 0271-678X

Digital Object Identifier (DOI)

  • 10.1038/jcbfm.2010.117


  • eng