Granulocyte-colony stimulating factor is involved in low-dose LPS-induced neuroprotection.

Granulocyte-colony stimulating factor (G-CSF) has recently been noted for neuroprotective function. Evidence has been given to indicate that G-CSF is naturally expressed in neurons and directly activates anti-apoptosis pathways. Finding out the agents inducing G-CSF production is of value for understanding the neuroprotection network in central nervous system. It is known that lipopolysaccharide (LPS) can induce macrophages to produce G-CSF. Here we demonstrate that hippocampal neurons exhibited the expression of toll-like receptor-4, and prove that low-dose LPS treatment increased the expression and production of G-CSF mRNA and protein in cultured neurons. We further indicate that the neutralization of G-CSF with corresponding anti-G-CSF antibodies abolished the neuroprotective effect of LPS pretreatment in N-methyl-D-aspartic acid-induced neuronal injury by MTT/CCK-8 assays and LDH release. Thus our results reveal that G-CSF may be involved in LPS-mediated neuroprotection in vivo.