http://stroke.ahajournals.org/content/48/8/2222?etoc=
This article requires a subscription to view the full text. If
you have a subscription you may use the login form below to view the
article. Access to this article can also be purchased.
Abstract
Background and Purpose—Recent
studies show that successful endovascular thrombectomy 6 to 12 hours
after stroke onset enhances functional outcomes 3 months later. In this
study, we investigated the effects of reperfusion after ischemia on
repair processes in the ischemic areas, as well as on functional
recovery, using mouse stroke models.
Methods—We
examined time-dependent histological changes and functional recovery
after transient middle cerebral artery occlusion of different durations,
including permanent middle cerebral artery occlusion, using the CB-17
(CB-17/lcr-+/+Jcl) mouse strain, which has poor pial collateral blood
flow.
Results—Large
microtubule-associated protein 2-negative areas of neuronal death were
produced in mice subjected to ≥60 minutes of ischemia followed by
reperfusion on day 1, while restricted microtubule-associated protein
2-negative regions were observed in mice subjected to a 45-minute period
of ischemia. A substantial reduction in microtubule-associated protein
2-negative areas was observed on day 7 in mice given early reperfusion
and was associated with better functional recovery. Klüver–Barrera
staining demonstrated that white matter injury on day 1 was
significantly lesser in mice with reperfusion. Immunohistochemistry and
electron microscopy revealed that a greater number of endothelial cells
were present in the infarct areas in mice with earlier reperfusion and
were associated with a more rapid recruitment of platelet-derived growth
factor receptor β-positive pericytes and subsequent intrainfarct
fibrosis. Early reperfusion also resulted in a greater accumulation of
glial fibrillary acidic protein–positive astrocytes in peri-infarct
areas. Peri-infarct astrogliosis was attenuated in platelet-derived
growth factor receptor β heterozygous knockout mice.
Conclusions—Early
reperfusion after ischemia enhances the survival of endothelial cells
and pericytes within ischemic areas even after the infarct is
established, resulting in efficient intrainfarct fibrosis and
peri-infarct astrogliosis. These effects might be associated with
efficient peri-infarct reorganization and functional recovery.
No comments:
Post a Comment