Pelin Cengiz1, Dila Zafer2, Jayadevi H Chandrashekhar3, Vishal Chanana2, Jacob Bogost2, Alex Waldman4, Becca Novak2, Douglas B Kintner2, Peter A Ferrazzano5. 1. Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA; Waisman Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA. Electronic address: cengiz@wisc.edu. 2. Waisman Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA. 3. Waisman Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA; University of Illinois at Urbana-Champaign, IL, USA. 4. Waisman Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA; Emory University School of Medicine, Atlanta, GA, USA. 5. Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA; Waisman Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
Abstract
BACKGROUND: Neuroinflammation plays an important role in ischemic brain injury and recovery, however the interplay between brain development and the neuroinflammatory response is poorly understood. We previously described age-dependent differences in the microglial response and the effect of microglial inhibition. Here we investigate whether age-dependent microglial responses may be related to pre-injury developmental differences in microglial phenotype. METHODS: Measures of microglia morphology were quantified using semi-automated software analysis of immunostained sections from postnatal day 2 (P2), P9, P30 and P60 mice using IMARIS. Microglia were isolated from P2, P9, P30 and P60 mice, and expression of markers of classical and alternative microglial activation was assessed, as well as transforming growth factor beta (TGF-β) receptor, Serpine1, Mer Tyrosine Kinase (MerTK), and the suppressor of cytokine signaling (SOCS3). Hypoxia-ischemia (HI) was induced in P9 and P30 mice using unilateral carotid artery ligation and exposure to 10% oxygen for 50 min. Microglia morphology and microglial expression of genes in the TGF-β and MerTK pathways were determined in ipsilateral and contralateral hippocampus. RESULTS: A progressive and significant increase in microglia branching morphology was seen in all brain regions from P2 to P30. No consistent classical or alternative activation profile was seen in isolated microglia. A clear transition to increased expression of TGF-β and its downstream effector serpine1 was seen between P9 and P30. A similar increase in expression was seen in MerTK and its downstream effector SOCS3. HI resulted in a significant decrease in branching morphology only in the P9 mice, and expression of TGF-β receptor, Serpine1, MerTK, and SOCS3 were elevated in P30 mice compared to P9 post-HI. CONCLUSION: Microglia maturation is associated with changes in morphology and gene expression, and microglial responses to ischemia in the developing brain differ based on the age at which injury occurs.
BACKGROUND: Neuroinflammation plays an important role in ischemic brain injury and recovery, however the interplay between brain development and the neuroinflammatory response is poorly understood. We previously described age-dependent differences in the microglial response and the effect of microglial inhibition. Here we investigate whether age-dependent microglial responses may be related to pre-injury developmental differences in microglial phenotype. METHODS: Measures of microglia morphology were quantified using semi-automated software analysis of immunostained sections from postnatal day 2 (P2), P9, P30 and P60mice using IMARIS. Microglia were isolated from P2, P9, P30 and P60mice, and expression of markers of classical and alternative microglial activation was assessed, as well as transforming growth factor beta (TGF-β) receptor, Serpine1, Mer Tyrosine Kinase (MerTK), and the suppressor of cytokine signaling (SOCS3). Hypoxia-ischemia (HI) was induced in P9 and P30mice using unilateral carotid artery ligation and exposure to 10% oxygen for 50 min. Microglia morphology and microglial expression of genes in the TGF-β and MerTK pathways were determined in ipsilateral and contralateral hippocampus. RESULTS: A progressive and significant increase in microglia branching morphology was seen in all brain regions from P2 to P30. No consistent classical or alternative activation profile was seen in isolated microglia. A clear transition to increased expression of TGF-β and its downstream effector serpine1 was seen between P9 and P30. A similar increase in expression was seen in MerTK and its downstream effector SOCS3. HI resulted in a significant decrease in branching morphology only in the P9 mice, and expression of TGF-β receptor, Serpine1, MerTK, and SOCS3 were elevated in P30mice compared to P9 post-HI. CONCLUSION: Microglia maturation is associated with changes in morphology and gene expression, and microglial responses to ischemia in the developing brain differ based on the age at which injury occurs.
Authors: Rosa C Paolicelli; Giulia Bolasco; Francesca Pagani; Laura Maggi; Maria Scianni; Patrizia Panzanelli; Maurizio Giustetto; Tiago Alves Ferreira; Eva Guiducci; Laura Dumas; Davide Ragozzino; Cornelius T Gross Journal: Science Date: 2011-07-21 Impact factor: 47.728
Authors: Michele D Binder; Junhua Xiao; Dennis Kemper; Gerry Z M Ma; Simon S Murray; Trevor J Kilpatrick Journal: PLoS One Date: 2011-03-10 Impact factor: 3.240
Authors: Amitabh Das; Jin Choul Chai; Sun Hwa Kim; Kyoung Sun Park; Young Seek Lee; Kyoung Hwa Jung; Young Gyu Chai Journal: PLoS One Date: 2015-03-26 Impact factor: 3.240
Authors: Ulas Cikla; Vishal Chanana; Douglas B Kintner; Eshwar Udho; Jens Eickhoff; Wendy Sun; Stephanie Marquez; Lucia Covert; Arel Otles; Robert A Shapiro; Peter Ferrazzano; Raghu Vemuganti; Jon E Levine; Pelin Cengiz Journal: eNeuro Date: 2016-01-28