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 language | English |
---|---|
Pages (from-to) | 135-144 |
Number of pages | 10 |
Journal | Experimental Neurology |
Volume | 272 |
DOIs | |
State | Published - 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