TLR3 ligand Poly IC Attenuates Reactive Astrogliosis and Improves Recovery of Rats after Focal Cerebral Ischemia.

Aims: Brain ischemia activates astrocytes in a process known as astrogliosis. Although this process has beneficial effects, excessive astrogliosis can impair neuronal recovery. Polyinosinic-polycytidylic acid (Poly IC) has shown neuroprotection against cerebral ischemia-reperfusion injury, but whether it regulates reactive astrogliosis and glial scar formation is not clear.

Astrocytic Toll-like receptor 3 is associated with ischemic preconditioning-induced protection against brain ischemia in rodents.

Background: Cerebral ischemic preconditioning (IPC) protects brain against ischemic injury. Activation of Toll-like receptor 3 (TLR3) signaling can induce neuroprotective mediators, but whether astrocytic TLR3 signaling is involved in IPC-induced ischemic tolerance is not known.

Methods: IPC was modeled in mice with three brief episodes of bilateral carotid occlusion.

Toll-like receptor 3 agonist Poly I:C protects against simulated cerebral ischemia in vitro and in vivo.

Aim: To examine the neuroprotective effects of the Toll-like receptor 3 (TLR3) agonist Poly I:C in acute ischemic models in vitro and in vivo.

Methods: Primary astrocyte cultures subjected to oxygen-glucose deprivation (OGD) were used as an in vitro simulated ischemic model. Poly I:C was administrated 2 h before OGD.