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
Language
- eng