Neuritin attenuates neuroinflammation and apoptosis in early brain injury after subarachnoid hemorrhage via endoplasmic reticulum stress-related inflammatory pathways.

Neuroinflammation is a key destructive pathophysiological process in early brain injury (EBI) following subarachnoid hemorrhage (SAH). Recent studies have discovered that endoplasmic reticulum stress-related inflammatory pathways include the IRE1α-TRAF2-NF-κB pathway, PERK-eIF2α-NF-κB pathway, and ATF6-AKT -NF-κB pathway leading to neuroinflammatory response. Neuritin is a neurotrophin that is involved in neuronal plasticity and regeneration. Studies have suggested that Neuritin has a vital role in reducing neuroinflammation, and can also decrease the expression of proteins related to endoplasmic reticulum stress following SAH. This suggests that Neuritin could be a potential therapeutic target for SAH and other neurological conditions. However, the regulatory mechanisms of Neuritin in ER stress-related inflammatory pathways after SAH are not yet fully understood. In this work, we discovered that the activation of ER stress-related inflammatory pathways leads to neuroinflammation, which further aggravates neuronal apoptosis after SAH. Our findings indicate that Neuritin overexpression play a neuroprotective role by inhibiting IRE1α-TRAF2-NF-κB pathway, PERK-eIF2α-NF-κB pathway, and ATF6-AKT-NF-κB pathway associated with endoplasmic reticulum stress. These inhibitory effects on neuroinflammation ultimately reduce nerve cell apoptosis.