VEGI attenuates the inflammatory injury and disruption of blood-brain barrier partly by suppressing the TLR4/NF-κB signaling pathway in experimental traumatic brain injury

Brain Res. 2015 Oct 5:1622:230-9. doi: 10.1016/j.brainres.2015.04.035. Epub 2015 Jun 12.

Abstract

Acute traumatic brain injury (TBI) tends to cause the over-activation of inflammatory response and disruption of blood brain barrier (BBB), associating with long-term cognitive and behavioral dysfunction. Vascular endothelial growth inhibitor (VEGI), as a suppressor in the angiogenesis specifically by inducing apoptosis in proliferating endothelial cells, has been applied to different diseases, especially the tumors. But rare study had been done in the field of brain injury. So in this study, we investigated the effects and mechanisms associated with VEGI-induced neuroprotection following CNS injury in mice TBI models. We demonstrated that the VEGI treatment reduced the contusion brain tissue loss, the permeation of inflammatory cells (MPO(+)) and the activation of microglia (Iba-1(+)). The treatment up-regulated the tight junction proteins (CLN5, ZO-1 and OCLN), which are vital importance for the integrity of the blood brain barrier (BBB), the B-cell lymphoma 2 (Bcl-2) cell survival factors, while down-regulated the expression of TLR4, NF-κB and inflammatory cytokines (IL-1β, TNF-α, iNOS). The treatment also decreased the expression of reactive astrocytes (GFAP(+)), as well as the VEGF, and lowered the permeability of Evens Blue (EB). These findings suggested that the VEGI-treatment could alleviate the post-traumatic excessive inflammatory response, and maintain the stability of blood vessels, remitting the secondary brain damage.

Keywords: Blood brain barrier; Inflammatory cytokine; Nuclear factor-kappa B (NF-κB); Traumatic brain injury.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Astrocytes / drug effects
  • Astrocytes / pathology
  • Astrocytes / physiology
  • Blood-Brain Barrier / drug effects*
  • Blood-Brain Barrier / pathology
  • Blood-Brain Barrier / physiopathology
  • Brain / drug effects
  • Brain / pathology
  • Brain / physiopathology
  • Brain Injuries / drug therapy*
  • Brain Injuries / pathology
  • Brain Injuries / physiopathology
  • Cytokines / metabolism
  • Disease Models, Animal
  • Male
  • Mice, Inbred C57BL
  • Microglia / drug effects
  • Microglia / pathology
  • Microglia / physiology
  • NF-kappa B / metabolism*
  • Neuroprotective Agents / administration & dosage*
  • Signal Transduction / drug effects
  • Toll-Like Receptor 4 / metabolism*
  • Treatment Outcome
  • Vascular Endothelial Growth Factor A / administration & dosage*

Substances

  • Cytokines
  • NF-kappa B
  • Neuroprotective Agents
  • Tlr4 protein, mouse
  • Toll-Like Receptor 4
  • Vascular Endothelial Growth Factor A