Lu Jiang1, Wanlu Li1, Muyassar Mamtilahun1, Yaying Song1, Yuanyuan Ma1, Meijie Qu1, Yifan Lu1, Xiaosong He1, Jieyu Zheng1, Zongjie Fu1, Zhijun Zhang1, Guo-Yuan Yang2, Yongting Wang2. 1. 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.). 2. 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.). ytwang@sjtu.edu.cn gyyang0626@163.com.
Abstract
BACKGROUND AND PURPOSE: 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. METHODS: Laser stimulation was delivered via an implanted optical fiber to inhibit or activate the striatal GABAergic neurons in Gad2-Arch-GFP or Gad2-ChR2-tdTomato 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. RESULTS: Inhibiting striatal GABAergic neuronal activity improved functional recovery, reduced brain atrophy volume, and prohibited cell death compared with the control (P<0.05). Microvessel density and bFGF (basic fibroblast growth factor) expression in the inhibition group were also increased (P<0.05). In contrast, activation of striatal GABAergic neurons resulted in adverse effects compared with the control (P<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. CONCLUSIONS: 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.
BACKGROUND AND PURPOSE: 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. METHODS: Laser stimulation was delivered via an implanted optical fiber to inhibit or activate the striatal GABAergic neurons in Gad2-Arch-GFP or Gad2-ChR2-tdTomato 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. RESULTS: Inhibiting striatal GABAergic neuronal activity improved functional recovery, reduced brain atrophy volume, and prohibited cell death compared with the control (P<0.05). Microvessel density and bFGF (basic fibroblast growth factor) expression in the inhibition group were also increased (P<0.05). In contrast, activation of striatal GABAergic neurons resulted in adverse effects compared with the control (P<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. CONCLUSIONS: 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.
Authors: Anna-Sophia Wahl; Eva Erlebach; Biagio Brattoli; Uta Büchler; Julia Kaiser; Benjamin V Ineichen; Alice C Mosberger; Shirin Schneeberger; Stefan Imobersteg; Martin Wieckhorst; Martina Stirn; Aileen Schroeter; Bjoern Ommer; Martin E Schwab Journal: J Cereb Blood Flow Metab Date: 2018-05-17 Impact factor: 6.200