EFFECT OF G-CSF GENE THERAPY IN A MICROGLIA MODEL OF STROKE

Cerebrovascular events (stroke) are a significant cause of morbidity and mortality worldwide. Ischemic stroke accounts for ~85% of all strokes and is caused by the blockade of blood flow to a certain area of the brain, resulting in oxygen and nutrient deprivation and ultimately cell death. Cerebral ischemia induces a strong neuroinflammatory response that contributes to tissue damage and is driven by changes in the gene expression profile and phenotype of brain cells including neurons, astrocytes, and microglia. Microglia are the resident immune and phagocytic cells of the central nervous system. They rapidly respond to ischemia by migrating to the site of injury and modulating the inflammatory response there. Although microglia may play a deleterious role in the acute phase of stroke, evidence suggests that they play an important role in the reduction of excitotoxic injury as well as in neurogenesis during the tissue regeneration phase. Granulocyte-colony stimulating factor (G-CSF) is a hematopoietic growth factor that has shown beneficial effects in models of ischemic stroke. G-CSF exerts its neuroprotective effects through different mechanisms including mobilization of haemopoietic stem cells, angiogenesis, neurogenesis, anti-inflammation, and anti-apoptosis. However, its effect on microglia is not well understood yet. The main objective of this project was to evaluate the protective and anti-inflammatory effect of G-CSF gene therapy against glutamate cytotoxicity in the human microglial clone 3 cell line (HMC3). Our results show that although G-CSF gene therapy did not significantly protect HMC3 cells against glutamate induced cell death, it reduced the expression levels of pro-inflammatory proteins NF-κB p65, IL-1β and IL-6, while increasing the phosphorylation of Akt, a regulator of cell survival and proliferation.