Inflammatory mediators reduce surface PrPc on human BMVEC resulting in decreased barrier integrity

Bezawit W. Megra, Eliseo A. Eugenin, Joan W. Berman

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

The cellular prion protein (PrPc) is a surface adhesion molecule expressed at junctions of various cell types including brain microvascular endothelial cells (BMVEC) that are important components of the blood–brain barrier (BBB). PrPc is involved in several physiological processes including regulation of epithelial cell barrier function and monocyte migration across BMVEC. BBB dysfunction and disruption are significant events in central nervous system (CNS) inflammatory processes including HIV neuropathogenesis. Tumor necrosis factor (TNF)-α and vascular endothelial growth factor (VEGF) are two inflammatory factors that have been implicated in the processes that affect BBB integrity. To examine the effect of inflammation on PrPc expression in BMVEC, we used these mediators and found that TNF-α and VEGF decrease surface PrPc on primary human BMVEC. We also showed that these factors decrease total PrPc protein as well as mRNA, indicating that they regulate expression of this protein by de novo synthesis. To determine the effect of PrPc loss from the surface of BMVEC on barrier integrity, we used small hairpin RNAs to knockdown PrPc. We found that the absence of PrPc from BMVEC causes increased permeability as determined by a fluorescein isothiocyanate (FITC)-dextran permeability assay. This suggests that cell surface PrPc is essential for endothelial monolayer integrity. To determine the mechanism by which PrPc downregulation leads to increased permeability of an endothelial monolayer, we examined changes in expression and localization of tight junction proteins, occludin and claudin-5, and found that decreased PrPc leads to decreased total and membrane-associated occludin and claudin-5. We propose that an additional mechanism by which inflammatory factors affect endothelial monolayer permeability is by decreasing cell-associated PrPc. This increase in permeability may have subsequent consequences that lead to CNS damage.

Original languageEnglish (US)
Pages (from-to)1-13
Number of pages13
JournalLaboratory Investigation
DOIs
StateAccepted/In press - Jun 29 2018

Fingerprint

Endothelial Cells
Permeability
Brain
Claudin-5
Occludin
Vascular Endothelial Growth Factor A
Central Nervous System
Tumor Necrosis Factor-alpha
Physiological Phenomena
Tight Junction Proteins
Intercellular Junctions
Cellular Structures
Small Interfering RNA
Monocytes
Proteins
Down-Regulation
Epithelial Cells
HIV
Inflammation
Messenger RNA

ASJC Scopus subject areas

  • Pathology and Forensic Medicine
  • Molecular Biology
  • Cell Biology

Cite this

Inflammatory mediators reduce surface PrPc on human BMVEC resulting in decreased barrier integrity. / Megra, Bezawit W.; Eugenin, Eliseo A.; Berman, Joan W.

In: Laboratory Investigation, 29.06.2018, p. 1-13.

Research output: Contribution to journalArticle

@article{80c9abb866f04014ad420260f71e6237,
title = "Inflammatory mediators reduce surface PrPc on human BMVEC resulting in decreased barrier integrity",
abstract = "The cellular prion protein (PrPc) is a surface adhesion molecule expressed at junctions of various cell types including brain microvascular endothelial cells (BMVEC) that are important components of the blood–brain barrier (BBB). PrPc is involved in several physiological processes including regulation of epithelial cell barrier function and monocyte migration across BMVEC. BBB dysfunction and disruption are significant events in central nervous system (CNS) inflammatory processes including HIV neuropathogenesis. Tumor necrosis factor (TNF)-α and vascular endothelial growth factor (VEGF) are two inflammatory factors that have been implicated in the processes that affect BBB integrity. To examine the effect of inflammation on PrPc expression in BMVEC, we used these mediators and found that TNF-α and VEGF decrease surface PrPc on primary human BMVEC. We also showed that these factors decrease total PrPc protein as well as mRNA, indicating that they regulate expression of this protein by de novo synthesis. To determine the effect of PrPc loss from the surface of BMVEC on barrier integrity, we used small hairpin RNAs to knockdown PrPc. We found that the absence of PrPc from BMVEC causes increased permeability as determined by a fluorescein isothiocyanate (FITC)-dextran permeability assay. This suggests that cell surface PrPc is essential for endothelial monolayer integrity. To determine the mechanism by which PrPc downregulation leads to increased permeability of an endothelial monolayer, we examined changes in expression and localization of tight junction proteins, occludin and claudin-5, and found that decreased PrPc leads to decreased total and membrane-associated occludin and claudin-5. We propose that an additional mechanism by which inflammatory factors affect endothelial monolayer permeability is by decreasing cell-associated PrPc. This increase in permeability may have subsequent consequences that lead to CNS damage.",
author = "Megra, {Bezawit W.} and Eugenin, {Eliseo A.} and Berman, {Joan W.}",
year = "2018",
month = "6",
day = "29",
doi = "10.1038/s41374-018-0090-z",
language = "English (US)",
pages = "1--13",
journal = "Laboratory Investigation",
issn = "0023-6837",
publisher = "Nature Publishing Group",

}

TY - JOUR

T1 - Inflammatory mediators reduce surface PrPc on human BMVEC resulting in decreased barrier integrity

AU - Megra, Bezawit W.

AU - Eugenin, Eliseo A.

AU - Berman, Joan W.

PY - 2018/6/29

Y1 - 2018/6/29

N2 - The cellular prion protein (PrPc) is a surface adhesion molecule expressed at junctions of various cell types including brain microvascular endothelial cells (BMVEC) that are important components of the blood–brain barrier (BBB). PrPc is involved in several physiological processes including regulation of epithelial cell barrier function and monocyte migration across BMVEC. BBB dysfunction and disruption are significant events in central nervous system (CNS) inflammatory processes including HIV neuropathogenesis. Tumor necrosis factor (TNF)-α and vascular endothelial growth factor (VEGF) are two inflammatory factors that have been implicated in the processes that affect BBB integrity. To examine the effect of inflammation on PrPc expression in BMVEC, we used these mediators and found that TNF-α and VEGF decrease surface PrPc on primary human BMVEC. We also showed that these factors decrease total PrPc protein as well as mRNA, indicating that they regulate expression of this protein by de novo synthesis. To determine the effect of PrPc loss from the surface of BMVEC on barrier integrity, we used small hairpin RNAs to knockdown PrPc. We found that the absence of PrPc from BMVEC causes increased permeability as determined by a fluorescein isothiocyanate (FITC)-dextran permeability assay. This suggests that cell surface PrPc is essential for endothelial monolayer integrity. To determine the mechanism by which PrPc downregulation leads to increased permeability of an endothelial monolayer, we examined changes in expression and localization of tight junction proteins, occludin and claudin-5, and found that decreased PrPc leads to decreased total and membrane-associated occludin and claudin-5. We propose that an additional mechanism by which inflammatory factors affect endothelial monolayer permeability is by decreasing cell-associated PrPc. This increase in permeability may have subsequent consequences that lead to CNS damage.

AB - The cellular prion protein (PrPc) is a surface adhesion molecule expressed at junctions of various cell types including brain microvascular endothelial cells (BMVEC) that are important components of the blood–brain barrier (BBB). PrPc is involved in several physiological processes including regulation of epithelial cell barrier function and monocyte migration across BMVEC. BBB dysfunction and disruption are significant events in central nervous system (CNS) inflammatory processes including HIV neuropathogenesis. Tumor necrosis factor (TNF)-α and vascular endothelial growth factor (VEGF) are two inflammatory factors that have been implicated in the processes that affect BBB integrity. To examine the effect of inflammation on PrPc expression in BMVEC, we used these mediators and found that TNF-α and VEGF decrease surface PrPc on primary human BMVEC. We also showed that these factors decrease total PrPc protein as well as mRNA, indicating that they regulate expression of this protein by de novo synthesis. To determine the effect of PrPc loss from the surface of BMVEC on barrier integrity, we used small hairpin RNAs to knockdown PrPc. We found that the absence of PrPc from BMVEC causes increased permeability as determined by a fluorescein isothiocyanate (FITC)-dextran permeability assay. This suggests that cell surface PrPc is essential for endothelial monolayer integrity. To determine the mechanism by which PrPc downregulation leads to increased permeability of an endothelial monolayer, we examined changes in expression and localization of tight junction proteins, occludin and claudin-5, and found that decreased PrPc leads to decreased total and membrane-associated occludin and claudin-5. We propose that an additional mechanism by which inflammatory factors affect endothelial monolayer permeability is by decreasing cell-associated PrPc. This increase in permeability may have subsequent consequences that lead to CNS damage.

UR - http://www.scopus.com/inward/record.url?scp=85049126514&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85049126514&partnerID=8YFLogxK

U2 - 10.1038/s41374-018-0090-z

DO - 10.1038/s41374-018-0090-z

M3 - Article

SP - 1

EP - 13

JO - Laboratory Investigation

JF - Laboratory Investigation

SN - 0023-6837

ER -