Long-term accumulation of microglia with proneurogenic phenotype concomitant with persistent neurogenesis in adult subventricular zone after stroke.

Neural stem cells (NSCs) in the adult rat subventricular zone (SVZ) generate new striatal neurons during several months after ischemic stroke. Whether the microglial response associated with ischemic injury extends into SVZ and influences neuroblast production is unknown. Here, we demonstrate increa...

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Main Authors: Thored, P, Heldmann, U, Gomes-Leal, W, Gisler, R, Darsalia, V, Taneera, J, Nygren, J, Jacobsen, SE, Ekdahl, C, Kokaia, Z, Lindvall, O
Format: Journal article
Language:English
Published: 2009
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author Thored, P
Heldmann, U
Gomes-Leal, W
Gisler, R
Darsalia, V
Taneera, J
Nygren, J
Jacobsen, SE
Ekdahl, C
Kokaia, Z
Lindvall, O
author_facet Thored, P
Heldmann, U
Gomes-Leal, W
Gisler, R
Darsalia, V
Taneera, J
Nygren, J
Jacobsen, SE
Ekdahl, C
Kokaia, Z
Lindvall, O
author_sort Thored, P
collection OXFORD
description Neural stem cells (NSCs) in the adult rat subventricular zone (SVZ) generate new striatal neurons during several months after ischemic stroke. Whether the microglial response associated with ischemic injury extends into SVZ and influences neuroblast production is unknown. Here, we demonstrate increased numbers of activated microglia in ipsilateral SVZ concomitant with neuroblast migration into the striatum at 2, 6, and 16 weeks, with maximum at 6 weeks, following 2 h middle cerebral artery occlusion in rats. In the peri-infarct striatum, numbers of activated microglia peaked already at 2 weeks and declined thereafter. Microglia in SVZ were resident or originated from bone marrow, with maximum proliferation during the first 2 weeks postinsult. In SVZ, microglia exhibited ramified or intermediate morphology, signifying a downregulated inflammatory profile, whereas amoeboid or round phagocytic microglia were frequent in the peri-infarct striatum. Numbers of microglia expressing markers of antigen-presenting cells (MHC-II, CD86) increased in SVZ but very few lymphocytes were detected. Using quantitative PCR, strong short- and long-term increase (at 1 and 6 weeks postinfarct) of insulin-like growth factor-1 (IGF-1) gene expression was detected in SVZ tissue. Elevated numbers of IGF-1-expressing microglia were found in SVZ at 2, 6, and 16 weeks after stroke. At 16 weeks, 5% of microglia but no other cells in SVZ expressed the IGF-1 protein, which mitigates apoptosis and promotes proliferation and differentiation of NSCs. The long-term accumulation of microglia with proneurogenic phenotype in the SVZ implies a supportive role of these cells for the continuous neurogenesis after stroke.
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spelling oxford-uuid:a724bfa6-05c2-4e23-912d-f4c6f6c84f5d2022-03-27T02:52:29ZLong-term accumulation of microglia with proneurogenic phenotype concomitant with persistent neurogenesis in adult subventricular zone after stroke.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:a724bfa6-05c2-4e23-912d-f4c6f6c84f5dEnglishSymplectic Elements at Oxford2009Thored, PHeldmann, UGomes-Leal, WGisler, RDarsalia, VTaneera, JNygren, JJacobsen, SEEkdahl, CKokaia, ZLindvall, ONeural stem cells (NSCs) in the adult rat subventricular zone (SVZ) generate new striatal neurons during several months after ischemic stroke. Whether the microglial response associated with ischemic injury extends into SVZ and influences neuroblast production is unknown. Here, we demonstrate increased numbers of activated microglia in ipsilateral SVZ concomitant with neuroblast migration into the striatum at 2, 6, and 16 weeks, with maximum at 6 weeks, following 2 h middle cerebral artery occlusion in rats. In the peri-infarct striatum, numbers of activated microglia peaked already at 2 weeks and declined thereafter. Microglia in SVZ were resident or originated from bone marrow, with maximum proliferation during the first 2 weeks postinsult. In SVZ, microglia exhibited ramified or intermediate morphology, signifying a downregulated inflammatory profile, whereas amoeboid or round phagocytic microglia were frequent in the peri-infarct striatum. Numbers of microglia expressing markers of antigen-presenting cells (MHC-II, CD86) increased in SVZ but very few lymphocytes were detected. Using quantitative PCR, strong short- and long-term increase (at 1 and 6 weeks postinfarct) of insulin-like growth factor-1 (IGF-1) gene expression was detected in SVZ tissue. Elevated numbers of IGF-1-expressing microglia were found in SVZ at 2, 6, and 16 weeks after stroke. At 16 weeks, 5% of microglia but no other cells in SVZ expressed the IGF-1 protein, which mitigates apoptosis and promotes proliferation and differentiation of NSCs. The long-term accumulation of microglia with proneurogenic phenotype in the SVZ implies a supportive role of these cells for the continuous neurogenesis after stroke.
spellingShingle Thored, P
Heldmann, U
Gomes-Leal, W
Gisler, R
Darsalia, V
Taneera, J
Nygren, J
Jacobsen, SE
Ekdahl, C
Kokaia, Z
Lindvall, O
Long-term accumulation of microglia with proneurogenic phenotype concomitant with persistent neurogenesis in adult subventricular zone after stroke.
title Long-term accumulation of microglia with proneurogenic phenotype concomitant with persistent neurogenesis in adult subventricular zone after stroke.
title_full Long-term accumulation of microglia with proneurogenic phenotype concomitant with persistent neurogenesis in adult subventricular zone after stroke.
title_fullStr Long-term accumulation of microglia with proneurogenic phenotype concomitant with persistent neurogenesis in adult subventricular zone after stroke.
title_full_unstemmed Long-term accumulation of microglia with proneurogenic phenotype concomitant with persistent neurogenesis in adult subventricular zone after stroke.
title_short Long-term accumulation of microglia with proneurogenic phenotype concomitant with persistent neurogenesis in adult subventricular zone after stroke.
title_sort long term accumulation of microglia with proneurogenic phenotype concomitant with persistent neurogenesis in adult subventricular zone after stroke
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