Osteopontin (OPN) is a phosphorylated glycoprotein, which is a
soluble cytokine capable of stimulating signal transduction pathways
in many different types of cells [12–14]. OPN is up-regulated
in the post-ischemic brain [15,16] and plays a protective role due
to its anti-inflammatory, neurogenic and nerve guidance effects
[17–19]. OPN was induced in a delayed manner in stroke animal
models [15,16], beginning from 24 h and peaking at 5 days; however,
supplementing OPN during the early period substantially
suppressed infarct formation and mitigated neuronal damage
[20,21], indicating a more active role of OPN in a hyperacute period
of post-ischemic brain.