Related Experiment Video

Updated: Mar 7, 2026

Oxygen-Glucose Deprivation and Reoxygenation as an In Vitro Ischemia-Reperfusion Injury Model for Studying Blood-Brain Barrier Dysfunction
08:56

Oxygen-Glucose Deprivation and Reoxygenation as an In Vitro Ischemia-Reperfusion Injury Model for Studying Blood-Brain Barrier Dysfunction

Published on: May 7, 2015

18.9K

TNFα alters occludin and cerebral endothelial permeability: Role of p38MAPK

Yawen Ni1, Tao Teng2, Runting Li3

  • 1Department of Bioengineering, University of Missouri, Columbia, Missouri, United States of America.

Plos One
|February 8, 2017
PubMed

Insights

Tumor necrosis factor-alpha (TNFα) rapidly increases occludin phosphorylation in brain endothelial cells, but prolonged exposure decreases occludin expression and increases blood-brain barrier permeability. p38MAPK inhibition partially mitigates these effects.

Area of Science:

  • Neuroscience
  • Cell Biology
  • Immunology

Background:

  • Occludin is a critical tight junction protein in cerebral endothelial cells (CECs) that regulates blood-brain barrier (BBB) function.
  • Pro-inflammatory cytokines and endotoxins can disrupt TJ proteins and BBB integrity, but the precise mechanisms remain unclear.
  • Understanding how specific cytokines impact occludin is vital for addressing BBB dysfunction.

Purpose of the Study:

  • To investigate the effects of TNFα, IL-1β, and LPS on occludin phosphorylation and expression in human cerebral endothelial cells (hCMEC/D3).
  • To explore the involvement of p38MAPK and ERK1/2 signaling pathways in TNFα-induced occludin modulation.
  • To assess the impact of TNFα on CEC morphology and BBB permeability.

Main Methods:

  • Human cerebral endothelial cells (hCMEC/D3) were stimulated with TNFα, IL-1β, and LPS.
  • Occludin phosphorylation was assessed via Western blot (band-shift analysis).
  • p38MAPK and ERK1/2 activation were measured, and specific inhibitors (SB202190, U0126) were used to probe signaling pathways. Cell morphology and permeability (FITC-dextran assay, TEER) were also evaluated.

Main Results:

  • TNFα induced rapid, transient occludin phosphorylation and transient p38MAPK/ERK1/2 activation, which were partially inhibited by SB202190 and U0126, respectively.
  • Prolonged TNFα and IL-1β treatment significantly decreased occludin expression, partially blocked by SB202190.
  • TNFα altered cell morphology and increased CEC layer permeability, but SB202190 did not fully reverse these changes.

Conclusions:

  • TNFα significantly impacts occludin phosphorylation and expression in CECs, involving p38MAPK and ERK1/2 pathways.
  • While p38MAPK inhibition can partially mitigate TNFα-induced changes in occludin expression, it is insufficient to fully restore BBB integrity.
  • These findings highlight complex TNFα-mediated effects on the BBB, suggesting that occludin phosphorylation and expression changes alone do not entirely explain permeability alterations.

More Related Videos

Methods for the Modulation and Analysis of NF-κB-dependent Adult Neurogenesis14:58

Methods for the Modulation and Analysis of NF-κB-dependent Adult Neurogenesis

Published on: February 13, 2014

14.8K
Setting-up an In Vitro Model of Rat Blood-brain Barrier BBB: A Focus on BBB Impermeability and Receptor-mediated Transport16:26

Setting-up an In Vitro Model of Rat Blood-brain Barrier BBB: A Focus on BBB Impermeability and Receptor-mediated Transport

Published on: June 28, 2014

43.5K

Related Concept Videos

Regulation of Angiogenesis and Blood Supply01:24

Regulation of Angiogenesis and Blood Supply

Rapidly dividing tumors, embryos, and wounded tissues require more oxygen than usual, lowering the oxygen concentration in the blood. At low oxygen or hypoxic conditions, an oxygen-sensitive transcription factor called the hypoxia-inducible factor 1 or HIF1 is activated. HIF1 is a dimeric protein of alpha (ɑ) and beta (β) subunits.  Under optimal oxygen conditions, HIF1β is present in the nucleus while HIF1ɑ remains in the cytosol. HIF1ɑ is hydroxylated by prolyl...
3.8K
Intracellular Signaling Affects Focal Adhesions01:17

Intracellular Signaling Affects Focal Adhesions

Integrins act both as extracellular input receivers and as intracellular processing activators. As their name suggests, integrins are entirely integrated into the membrane structure. Their hydrophobic membrane-spanning regions interact with the phospholipid bilayer's hydrophobic region. These membrane receptors provide extracellular attachment sites for effectors like hormones and growth factors. They activate intracellular response cascades when their effectors are bound and active.
Some...
3.7K
NF-κB-dependent Signaling Pathway02:26

NF-κB-dependent Signaling Pathway

The transcription factor NF-κB was discovered in 1986 in the lab of Nobel laureate Professor David Baltimore, for its interaction with the immunoglobulin light chain enhancer in B-cells. After more than three decades of study, it is now evident that NF-κB regulates the expression of over 100 genes. Most of these genes play an essential role in the innate and adaptive immune responses as well as the inflammatory responses of animals.
NF-κB-dependent Signaling Mechanism
The...
10.2K