title: White matter tract and glial-associated changes in 5-hydroxymethylcytosine following chronic cerebral hypoperfusion.
abstract: White matter abnormalities due to age-related cerebrovascular alterations is a common pathological hallmark associated with functional impairment in the elderly which has been modeled in chronically hypoperfused mice. 5-Methylcytosine (5mC) and its oxidized derivative 5-hydroxymethylcytosine (5hmC) are DNA modifications that have been recently linked with age-related neurodegeneration and cerebrovascular pathology. Here we conducted a pilot investigation of whether chronic cerebral hypoperfusion might affect genomic distribution of these modifications and/ or a Ten-Eleven Translocation protein 2 (TET2) which catalyses hydroxymethylation in white and grey matter regions of this animal model. Immunohistochemical evaluation of sham and chronically hypoperfused mice a month after surgery revealed significant (p<0.05) increases in the proportion of 5hmC positive cells, Iba1 positive inflammatory microglia, and NG2 positive oligodendroglial progenitors in the hypoperfused corpus callosum. In the same white matter tract there was an absence of hypoperfusion-induced alterations in the proportion of 5mC, TET2 positive cells and CC1 positive mature oligodrendrocytes. Correlation analysis across animals within both treatment groups demonstrated a significant association of the elevated 5hmC levels with increases in the proportion of inflammatory microglia only (p=0.01) in the corpus callosum. In vitro studies revealed that 5hmC is lost during oligodendroglial maturation but not microglial activation. Additionally, TET1, TET2, and TET3 protein levels showed dynamic alterations during oligodendroglial development and following oxidative stress in vitro. Our study suggests that 5hmC exhibits white matter tract and cell type specific dynamics following chronic cerebral hypoperfusion in mice.
authors.affiliation: Centre for Clinical Brain Sciences, School of Clinical Sciences, Chancellor's Building, University of Edinburgh, 49 Little France Crescent, Edinburgh EH16 4SB, UK; The Miami Project to Cure Paralysis, Lois Pope Life Center, University of Miami, 1095 NW 14th Terrace, Miami, FL 33136, USA. Electronic address: y.tsenkina1@med.miami.edu.
authors.forename: Yanina
authors.initials: Y
authors.lastname: Tsenkina
authors.affiliation: Centre for Clinical Brain Sciences, School of Clinical Sciences, Chancellor's Building, University of Edinburgh, 49 Little France Crescent, Edinburgh EH16 4SB, UK; Wolfson Centre for Stem Cells, Tissue Engineering and Modeling (STEM), Division of Cancer and Stem Cells, School of Medicine, Center for Biomolecular Sciences, University Park, University of Nottingham, University Park NG7 2RD, UK.
authors.forename: Alexey
authors.initials: A
authors.lastname: Ruzov
authors.affiliation: Centre for Clinical Brain Sciences, School of Clinical Sciences, Chancellor's Building, University of Edinburgh, 49 Little France Crescent, Edinburgh EH16 4SB, UK; Pharmacology and Toxicology Department, Otago School of Medical Sciences, University of Otago, Dunedin, NZ.
authors.forename: Catherine
authors.initials: C
authors.lastname: Gliddon
authors.affiliation: Centre for Neuroregeneration, University of Edinburgh, 49 Little France Crescent, Edinburgh EH16 4SB, UK.
authors.forename: Karen
authors.initials: K
authors.lastname: Horsburgh
authors.affiliation: Centre for Clinical Brain Sciences, School of Clinical Sciences, Chancellor's Building, University of Edinburgh, 49 Little France Crescent, Edinburgh EH16 4SB, UK; Roslin Cells, Scottish Centre for Regenerative Medicine, 5 Little France Drive, Edinburgh EH16 4UX, UK. Electronic address: paul.desousa@ed.ac.uk.
authors.forename: Paul A
authors.initials: PA
authors.lastname: De Sousa
mesh_terms: D044503:5-Methylcytosine / Q000031:analogs & derivatives; D000818:Animals; D000071183:Autophagy-Related Proteins; D002135:Calcium-Binding Proteins / Q000378:metabolism; D002561:Cerebrovascular Disorders / Q000378:metabolism*; D002908:Chronic Disease; D003337:Corpus Callosum / Q000378:metabolism*; D003596:Cytosine / Q000031:analogs & derivatives* / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D049308:Dioxygenases; D004195:Disease Models, Animal; D066128:Gray Matter / Q000378:metabolism; D007150:Immunohistochemistry; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D008297:Male; D008810:Mice, Inbred C57BL; D008840:Microfilament Proteins / Q000378:metabolism; D058953:Neural Stem Cells / Q000378:metabolism; D009457:Neuroglia / Q000378:metabolism*; D018384:Oxidative Stress / Q000502:physiology; D010865:Pilot Projects; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D011897:Random Allocation; D066127:White Matter / Q000378:metabolism*
chemical_list: C491049:Aif1 protein, mouse; D000071183:Autophagy-Related Proteins; D002135:Calcium-Binding Proteins; D004268:DNA-Binding Proteins; D047908:Intracellular Signaling Peptides and Proteins; D008840:Microfilament Proteins; D011518:Proto-Oncogene Proteins; C428743:Rb1cc1 protein, mouse; C540839:TET1 protein, mouse; C011865:5-hydroxymethylcytosine; D044503:5-Methylcytosine; D003596:Cytosine; D049308:Dioxygenases; C551914:Tet2 protein, mouse; C551915:Tet3 protein, mouse
keywords: 5-Hydroxymethylcytosine; 5-Methylcytosine; Chronic cerebral hypoperfusion; Epigenetics; TET proteins; White matter