关键词: 神经再生, 脑源性神经营养因子, 表皮生长因子, 细胞因子信号传导抑制因子2, 神经元特异性烯醇酶, 胶质纤维酸蛋白, 巢蛋白, BrU, 神经功能, 大脑中动脉闭塞, 星形胶质细胞

Abstract:

Neural stem cells have great potential for the development of novel therapies for nervous system diseases. However, the proliferation of endogenous neural stem cells following brain ischemia is insufficient for central nervous system self-repair. Ginkgolide B has a robust neuroprotective effect. In this study, we investigated the cell and molecular mechanisms underlying the neuroprotective effect of ginkgolide B on focal cerebral ischemia/reperfusion injury in vitro and in vivo. Neural stem cells were treated with 20, 40 and 60 mg/L ginkgolide B in vitro. Immunofluorescence staining was used to assess cellular expression of neuron-specific enolase, glial fibrillary acid protein and suppressor of cytokine signaling 2. After treatment with 40 and 60 mg/L ginkgolide B, cells were large, with long processes. Moreover, the proportions of neuron-specific enolase-, glial fibrillary acid protein- and suppressor of cytokine signaling 2-positive cells increased. A rat model of cerebral ischemia/reperfusion injury was established by middle cerebral artery occlusion. Six hours after ischemia, ginkgolide B (20 mg/kg) was intraperitoneally injected, once a day. Zea Longa’s method was used to assess neurological function. Immunohistochemistry was performed to evaluate the proportion of nestin-, neuron-specific enolase- and glial fibrillary acid protein-positive cells. Real-time quantitative polymerase chain reaction was used to measure mRNA expression of brain-derived neurotrophic factor and epidermal growth factor. Western blot assay was used to analyze the expression levels of brain-derived neurotrophic factor and suppressor of cytokine signaling 2. Ginkgolide B decreased the neurological deficit score, increased the proportion of nestin-, neuron-specific enolase- and glial fibrillary acid protein-positive cells, increased the mRNA expression of brain-derived neurotrophic factor and epidermal growth factor,and increased the expression levels of brain-derived neurotrophic factor and suppressor of cytokine signaling 2 in the ischemic penumbra.Together, the in vivo and in vitro findings suggest that ginkgolide B improves neurological function by promoting the proliferation and differentiation of neural stem cells in rats with cerebral ischemia/reperfusion injury.

Key words: nerve regeneration, brain-derived neurotrophic factor, epidermal growth factor, suppressor of cytokine signaling 2, neuron-specific enolase, glial fibrillary acid protein, nestin, bromodeoxyuridine, neurological function, middle cerebral artery occlusion, astrocytes, neural regeneration