G-CSF attenuates neuroinflammation and stabilizes the blood-brain barrier via the PI3K/Akt/GSK-3β signaling pathway following neonatal hypoxia-ischemia in rats

Li Li, Devin W. McBride, Desislava Doycheva, Brandon J. Dixon, Paul R. Krafft, John H. Zhang, Jiping Tang

Research output: Contribution to journalArticlepeer-review

Abstract

Objective: Neonatal hypoxia occurs in approximately 60% of premature births and is associated with a multitude of neurological disorders. While various treatments have been developed, translating them from bench to bedside has been limited. We previously showed G-CSF administration was neuroprotective in a neonatal hypoxia-ischemia rat pup model, leading us to hypothesize that G-CSF inactivation of GSK-3β via the PI3K/Akt pathway may attenuate neuroinflammation and stabilize the blood-brain barrier (BBB). Methods: P10 Sprague-Dawley rat pups were subjected to unilateral carotid artery ligation followed by hypoxia for 2.5. h. We assessed inflammation by measuring expression levels of IKKβ, NF-κB, TNF-α, IL-1β, IL-10, and IL-12 as well as neutrophil infiltration. BBB stabilization was evaluated by measuring Evans blue extravasation, and Western blot analysis of Claudin-3, Claudin-5, ICAM-1, and VCAM-1. Measurements and main results: First, the time course study showed that p-β-catenin/β-catenin, IKKβ, and NF-κB expression levels peaked at 48. h post-HI. The knockdown of GSK-3β with siRNA prevented the HI-induced increase of p-β-catenin/β-catenin, IKKβ, and NF-κB expression levels 48. h after HI. G-CSF treatment reduced brain water content and neuroinflammation by downregulating IKKβ, NF-κB, TNF-α, IL-1β, and IL-12 and upregulating IL-10, thereby reducing neutrophil infiltration. Additionally, G-CSF stabilizes the BBB by downregulating VCAM-1 and ICAM-1, as well as upregulating Claudins 3 and 5 in endothelial cells. G-CSFR knockdown by siRNA and Akt inhibition by Wortmannin reversed G-CSF's neuroprotective effects. Conclusions: We demonstrate G-CSF plays a pivotal role in attenuating neuroinflammation and BBB disruption following HI by inactivating GSK-3β through the PI3K/Akt pathway.

Original languageEnglish
Pages (from-to)135-144
Number of pages10
JournalExperimental Neurology
Volume272
DOIs
StatePublished - Oct 1 2015

ASJC Scopus Subject Areas

  • Neurology
  • Developmental Neuroscience

Keywords

  • Blood-brain barrier (BBB)
  • GSK-3β
  • Granulocyte-colony stimulating factor (G-CSF)
  • Hypoxia-ischemia (HI)
  • Neonatal
  • Neuroinflammation
  • PI3K
  • Animals, Newborn
  • Phosphatidylinositol 3-Kinases/metabolism
  • Rats
  • Functional Laterality
  • Glycogen Synthase Kinase 3/genetics
  • Granulocyte Colony-Stimulating Factor/therapeutic use
  • Proto-Oncogene Proteins c-akt/metabolism
  • Rats, Sprague-Dawley
  • Signal Transduction/drug effects
  • Anti-Inflammatory Agents/therapeutic use
  • Animals
  • Hypoxia-Ischemia, Brain/complications
  • Blood-Brain Barrier/drug effects
  • Encephalitis/drug therapy
  • Cytokines/metabolism
  • RNA, Small Interfering/therapeutic use
  • Disease Models, Animal

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