In Alzheimer's disease and ischemic stroke, intranasal insulin can act as a neuroprotective agent. However, whether intranasal insulin has a neuroprotective effect in intracerebral hemorrhage and its potential mechanisms remain poorly understood. In this study, a mouse model of autologous blood-induced intracerebral hemorrhage was treated with 0.5, 1, or 2 IU insulin via intranasal delivery, twice per day, until 24 or 72 hours after surgery. Compared with saline treatment, 1 IU intranasal insulin treatment significantly reduced hematoma volume and brain edema after cerebral hemorrhage, decreased blood-brain barrier permeability and neuronal degeneration damage, reduced neurobehavioral deficits, and improved the survival rate of mice. Expression levels of p-AKT and p-GSK3β were significantly increased in the perihematoma tissues after intranasal insulin therapy. Our findings suggest that intranasal insulin therapy can protect the neurological function of mice after intracerebral hemorrhage through the AKT/GSK3β signaling pathway. The study was approved by the Ethics Committee of the North Sichuan Medical College of China (approval No. NSMC(A)2019(01)) on January 7, 2019.
Keywords: AKT; blood-brain barrier; brain edema; glycogen synthase kinase-3; hematoma; insulin; intracerebral hemorrhage; intranasal insulin; neurological impairment; neuronal degeneration; neuroprotection.