Osteopontin as a two-sided mediator in acute neuroinflammation in rat models.

Osteopontin (OPN) plays an important role in the initiation of inflammation, affecting cell adhesion, chemotaxis, immune regulation, and protection against apoptosis, depending on its intracellular or extracellular localization. Although OPN in inflammation of the autoimmune central nervous system is proinflammatory, recent studies have shown that OPN during the induction stage of inflammation may also participate in neuroprotection and neurite growth. The present review examines the dual roles of OPN, specifically, its proinflammatory and subsequent neuroprotective roles, in acute neuroinflammation in rat models, including experimental autoimmune encephalomyelitis, brain injury, and autoimmune neuritis. All of these models are characterized by acute neuroinflammation, followed by remodeling of neural tissues.