Abstract
BACKGROUND AND PURPOSE-: Netrin-1 (NT-1) stimulates endothelial cell proliferation and migration in vitro and promotes focal neovascularization in the adult brain in vivo. This in vivo study in mice investigated the effect of NT-1 hyperexpression on focal angiogenesis and long-term functional outcome after transient middle cerebral artery occlusion (tMCAO). METHODS-: Adeno-associated viral vectors carrying either the NT-1 gene (AAV-NT-1) or GFP (AAV-GFP) were generated and injected into the brains of separate groups of 93 mice. Seven days later, tMCAO followed by 7-28 days of reperfusion were carried out. Histological outcomes and behavioral deficits were quantified 7-28 days after tMCAO. Small cerebral vessel network and angiogenesis were assessed 28 days after tMCAO, using synchrotron radiation microangiography and immunohistochemistry. RESULTS-: Western blot and immunohistochemistry showed that on the day of tMCAO, NT-1 hyperexpression had been achieved in both normal and ischemic hemispheres. Immunofluorescence imaging showed that NT-1 expression was primarily in neurons and astrocytes. Ischemia-induced infarction in the NT-1 hyperexpression group was attenuated in comparison to saline or AAV-GFP-treated groups (P<0.01). Similarly, neurological deficits were greatly improved in AAV-NT-1-treated mice compared with mice in saline or AAV-GFP-treated groups (P<0.05). In addition, angiogenesis was increased in AAV-NT-1-treated mice compared with the other 2 groups (P<0.05). In vivo synchrotron radiation microangiography 28 days after tMCAO revealed more branches in AAV-NT-1-treated mice than in other groups. CONCLUSIONS-: AAV-NT-1 induced NT-1 hyperexpression before tMCAO reduced infarct size, enhanced neovascularization, and improved long-term functional recovery.
Original language | English |
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Pages (from-to) | 838-843 |
Number of pages | 6 |
Journal | Stroke |
Volume | 43 |
Issue number | 3 |
DOIs | |
State | Published - Mar 2012 |
Keywords
- adeno-associated virus
- angiogenesis
- gene transfer
- ischemia
- middle cerebral artery occlusion
- netrin-1