AAV-mediated netrin-1 overexpression increases peri-infarct blood vessel density and improves motor function recovery after experimental stroke

• Published in: Neurobiology of disease Vol. 44; no. 1; pp. 73 - 83
• Main Authors: Sun, Hui, Le, Thang, Chang, Tiffany T.J, Habib, Aisha, Wu, Steven, Shen, Fanxia, Young, William L, Su, Hua, Liu, Jialing
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.10.2011; Elsevier
• Subjects: Adeno-associated virus; Angiogenesis; Animals; Barnes maze; Behavior, Animal - physiology; Blotting, Western; Capillaries - pathology; Cell Movement - genetics; Cell Movement - physiology; Cerebral Cortex - metabolism; Cerebral Cortex - pathology; Cerebral Infarction - pathology; Cerebral Infarction - psychology; Cerebral Infarction - therapy; Dependovirus - genetics; Distal MCA occlusion; Doublecortin; Exploratory Behavior - physiology; Fluorescent Antibody Technique, Indirect; Forelimb asymmetry; Functional Laterality - physiology; Gene Transfer Techniques; Genetic Therapy - methods; Immunohistochemistry; Infarction, Middle Cerebral Artery - pathology; Infarction, Middle Cerebral Artery - therapy; Maze Learning - physiology; Microvessel density; Motor Activity - physiology; Movement - physiology; Neovascularization, Physiologic - genetics; Nerve Growth Factors - biosynthesis; Netrin-1; Neurology; Postural Balance - physiology; Rats; Reverse Transcriptase Polymerase Chain Reaction; Stroke - pathology; Stroke - psychology; Stroke - therapy; Tumor Suppressor Proteins - biosynthesis; Distal MCA occlusion; Angiogenesis; Barnes maze; Microvessel density; Doublecortin; Forelimb asymmetry
• ISSN: 0969-9961; 1095-953X
• DOI: 10.1016/j.nbd.2011.06.006

Abstract Apart from its role in axon guidance, netrin-1 is also known to be pro-angiogenic. The aim of this study is to determine whether adeno-associated viral (AAV) mediated overexpression of netrin-1 improves post-stroke neurovascular structure and recovery of function. AAV-Netrin-1 or AAV-LacZ of 1 × 1010 genome copies each was injected medial and posterior to ischemic lesion at one hour following reperfusion using the distal middle cerebral artery occlusion (MCAO) method. Quantitative RT-PCR revealed that the expression of netrin-1 transgene began as early as one day and increased dramatically about 3 weeks following vector injection. Western blot analysis and confocal microscopy suggested that both the endogenous and transduced netrin-1 were expressed in the neurons of the peri-infarct cortex after MCAO. AAV-mediated netrin-1 overexpression significantly increased vascular density in the peri-infarct cortex and promoted the migration of immature neurons into the peri-infarct white matter, but it did not significantly reduce infarct size. Netrin-1 overexpression also enhanced post-stroke locomotor activity, improved exploratory behavior, and reduced ischemia-induced motor asymmetry in forelimb usage. However, it had little effect on post-stroke spatial learning and memory. Our results suggest that AAV mediated netrin-1 overexpression improves peri-infarct vascular density and post stroke motor function.