Doublecortin-expressing cells in the ischemic penumbra of a small-vessel stroke.
A cortical lesion was induced by disrupting the medium-size pial vessels, which led to a cone-shaped cortical lesion and turned into a fluid-filled cavity surrounded by a glial acidic fibrillary protein-positive (GFAP(+)) glia limitans 21 days after injury. Therefore, it mimics conditions of lacunar infarctions, one of the most frequent human stroke pathologies. Doublecortin (DCX)-positive cells were present in the neocortex and corpus callosum at the base of the lesion. The number of DCX-positive cells in the corpus callosum was significantly increased from day 5 to day 14 compared with the control group. In contrast, there were no DCX-positive cells in neocortex of control animals; the DCX-positive cells appeared in the neocortex after lesioning and were maintained until 14 days postlesioning. Some of the DCX-positive cells were also immunoreactive for beta III-tubulin, another marker of immature neurons. They did not stain positively for markers of glia cells. The presence of these DCX-positive cells near the lesion might indicate a migratory pathway for developing neuroblasts from the subventricular zone (SVZ) through the corpus callosum to the lesion. SVZ cells were labeled with a lipophilic molecule, 5- (and 6-) carboxyfluorescein diacetate succinimidyl ester (CFSE) stereotaxical injections. Although rostral migratory stream and olfactory bulb were intensely labeled, no CFSE-containing cells were found in the cortex beneath the lesion. These results do not support the idea that the DCX-positive cells were originating from neural precursors of the SVZ, but they might be generated from local progenitor cells.
Hua
Rui
R
Department of Physiology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
Doucette
Ron
R
Walz
Wolfgang
W
D000818:Animals; D020520:Brain Infarction / Q000209:etiology / Q000378:metabolism / Q000473:pathology; D002454:Cell Differentiation; D002465:Cell Movement / Q000502:physiology; D000089622:Doublecortin Domain Proteins; D000089662:Doublecortin Protein; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D008297:Male; D018613:Microscopy, Confocal; D008869:Microtubule-Associated Proteins / Q000096:biosynthesis*; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D009479:Neuropeptides / Q000096:biosynthesis*; D010841:Pia Mater / Q000098:blood supply; D051381:Rats; D017208:Rats, Wistar; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism*; D020521:Stroke / Q000150:complications / Q000378:metabolism* / Q000473:pathology
C000714328:DCX protein, human; C000714848:Dcx protein, rat; D000089622:Doublecortin Domain Proteins; D000089662:Doublecortin Protein; D008869:Microtubule-Associated Proteins; D009479:Neuropeptides