Jiang Lu, Li Wanlu, Mamtilahun Muyassar, Song Yaying, Ma Yuanyuan, Qu Meijie, Lu Yifan, He Xiaosong, Zheng Jieyu, Fu Zongjie, Zhang Zhijun, Yang Guo-Yuan, Wang Yongting
From the Neuroscience and Neuroengineering Research Center, Med-X Research Institute and School of Biomedical Engineering (L.J., W.L., M.M., Y.L., Z.Z., G.-Y.Y., Y.W.), Department of Neurology, Ruijin Hospital, School of Medicine (Y.S., Y.M., M.Q., Z.F., G.-Y.Y.), School of Agriculture and Biology (J.Z.), and Brain Science and Technology Research Center (Y.W.), Shanghai Jiao Tong University, Shanghai, China; and Department of Human Anatomy, School of Basic Medical Science, and Institute of Neuroscience and the Second Affiliated Hospital, Guangzhou Medical University, Guangzhou 510182, China (X.H.).
Stroke. 2017 Dec;48(12):3375-3383. doi: 10.1161/STROKEAHA.117.019017. Epub 2017 Nov 16.
Striatal GABAergic neuron is known as a key regulator in adult neurogenesis. However, the specific role of striatal GABAergic neuronal activity in the promotion of neurological recovery after ischemic stroke remains unknown. Here, we used optogenetic approach to investigate these effects and mechanism.
Laser stimulation was delivered via an implanted optical fiber to inhibit or activate the striatal GABAergic neurons in or mice (n=80) 1 week after 60-minute transient middle cerebral artery occlusion. Neurological severity score, brain atrophy volume, microvessel density, and cell morphological changes were examined using immunohistochemistry. Gene expression and protein levels of related growth factors were further examined using real-time polymerase chain reaction and Western blotting.
Inhibiting striatal GABAergic neuronal activity improved functional recovery, reduced brain atrophy volume, and prohibited cell death compared with the control (<0.05). Microvessel density and bFGF (basic fibroblast growth factor) expression in the inhibition group were also increased (<0.05). In contrast, activation of striatal GABAergic neurons resulted in adverse effects compared with the control (<0.05). Using cocultures of GABAergic neurons, astrocytes, and endothelial cells, we further demonstrated that the photoinhibition of GABAergic neuronal activity could upregulate bFGF expression in endothelial cells, depending on the presence of astrocytes. The conditioned medium from the aforementioned photoinhibited 3-cell coculture system protected cells from oxygen glucose deprivation injury.
After ischemic stroke, optogenetic inhibition of GABAergic neurons upregulated bFGF expression by endothelial cells and promoted neurobehavioral recovery, possibly orchestrated by astrocytes. Optogenetically inhibiting neuronal activity provides a novel approach to promote neurological recovery.
纹状体γ-氨基丁酸能神经元是成人神经发生的关键调节因子。然而，纹状体γ-氨基丁酸能神经元活动在缺血性中风后促进神经功能恢复中的具体作用尚不清楚。在此，我们采用光遗传学方法研究这些作用及机制。
在60分钟短暂性大脑中动脉闭塞1周后，通过植入的光纤进行激光刺激，以抑制或激活野生型或转基因小鼠（n = 80）纹状体γ-氨基丁酸能神经元。使用免疫组织化学检测神经严重程度评分、脑萎缩体积、微血管密度和细胞形态变化。使用实时聚合酶链反应和蛋白质印迹进一步检测相关生长因子的基因表达和蛋白水平。
与对照组相比，抑制纹状体γ-氨基丁酸能神经元活动可改善功能恢复、减少脑萎缩体积并抑制细胞死亡（P<0.05）。抑制组的微血管密度和碱性成纤维细胞生长因子（bFGF）表达也增加（P<0.05）。相比之下，与对照组相比，激活纹状体γ-氨基丁酸能神经元产生了不利影响（P<0.05）。使用γ-氨基丁酸能神经元、星形胶质细胞和内皮细胞的共培养，我们进一步证明，γ-氨基丁酸能神经元活动的光抑制可上调内皮细胞中bFGF的表达，这取决于星形胶质细胞的存在。上述光抑制三细胞共培养系统的条件培养基可保护细胞免受氧葡萄糖剥夺损伤。
缺血性中风后，光遗传学抑制γ-氨基丁酸能神经元可上调内皮细胞中bFGF的表达并促进神经行为恢复，这可能是由星形胶质细胞协调完成的。光遗传学抑制神经元活动为促进神经功能恢复提供了一种新方法。
