Assessment of Neurogenesis by BrdU Labeling After Traumatic Brain Injury

Post-stroke gastrodin treatment ameliorates ischemic injury and increases neurogenesis and restores the Wnt/β-Catenin signaling in focal cerebral ischemia in mice

Cerebral ischemic stroke is one of the leading causes of death and disability worldwide, and the only available drug treatment is limited to a short window following the ischemic event. Gastrodin is the major bioactive constituent extracted from thetuberGastrodia elata, and is currently used to treat dizziness in the clinic. "Early" application of gastrodin (before modeling or immediately after ischemic injury) has shown antioxidative and neuroprotective effects in a transient focal brain ischemia model in rodents; however, it is not known whether the delayed administration of gastrodin after permanent focal cerebral ischemia ameliorates neural injury and increases neurogenesis. In this study, we performed a permanent middle cerebral artery occlusion (MCAO) model for the study of cerebral ischemic stroke in adult male mice to examine the effects of gastrodin. Gastrodin treatment that was started "late" (one day after the ischemic injury) significantly improved neural function, reduced infarct volume and apoptosis, and increased the number of DCX/BrdU double-positive cells in permanent MCAO mice. Moreover, gastrodin treatment markedly preserved the Wnt/β-Catenin signaling pathway, which could promote neurogenesis and provide neuroprotection brain injury. Our findings suggest that gastrodin treatment following ischemic injury can induce neuroprotection, promote neurogenesis and restored the Wnt /β-Catenin signaling pathway.

Wip1 knockout inhibits neurogenesis by affecting the Wnt/β-catenin signaling pathway in focal cerebral ischemia in mice

Neurogenesis correlates closely with the recovery of neural function after brain ischemia but the critical proteins and signaling pathways involved remain unclear. The phosphatase WIP1 has been shown to regulate neurogenesis in models of aging. However, it is not known if WIP1 affects neurogenesis and functional recovery after brain ischemia. To explore these questions, we performed permanent middle cerebral artery occlusion (MCAO) in mice and performed BrdU labeling, neurobehavioral testing, western blotting, and immunofluorescence staining. We found that ischemia induced WIP1 expression in the area bordering the injury. Compared to wild-type mice, the knockout of the Wip1 gene inhibited neurological functional recovery, reduced the expression of doublecortin, and inactivated the Wnt/β-Catenin signaling pathway in cerebral ischemia in mice. Pharmacological activation of the Wnt/β-Catenin signaling pathway compensated for the Wip1 knockout-induced deficit in neuroblast formation in animals with MCAO. These findings indicate that WIP1 is essential for neurogenesis after brain injury by activating the Wnt/β-Catenin signaling pathway.