Enhanced susceptibility of S-100B transgenic mice to neuroinflammation and neuronal dysfunction induced by intracerebroventricular infusion of human beta-amyloid.
S-100B is an astrocyte-derived protein that is increased in focal areas of the brain most severely affected by neuropathological changes in Alzheimer's disease (AD). Cell-based and clinical studies have implicated S-100B in progression of a pathologic, glial-mediated pro-inflammatory state in the CNS. However, the relationship between S-100B levels and susceptibility to AD-relevant neuroinflammation and neuronal dysfunction in vivo has not been determined. To test the hypothesis that overexpression of S-100B increases vulnerability to beta-amyloid (Abeta)-induced damage, we used S-100B-overexpressing transgenic (Tg) and S-100B knockout (KO) mice in a mouse model that involves intracerebroventricular infusion of human oligomeric Abeta1-42. This model mimics many features of AD, including robust neuroinflammation, Abeta plaques, synaptic damage and neuronal loss in the hippocampus. S-100B Tg, KO, and wild-type (WT) mice were infused with Abeta for 28 days, sacrificed at 60 days, and hippocampal endpoints analyzed. We found that Tg mice showed increased vulnerability to Abeta-induced neuropathology relative to either WT or KO mice. Specifically, Tg mice exhibited enhanced glial activation and neuroinflammation, increased nitrotyrosine staining (a marker of glial-induced neuronal damage), and more pronounced loss of synaptic markers. Interestingly, Tg mice showed no significant differences in Abeta plaque burden compared with WT or KO mice, suggesting that, as in the human situation, the severity of neuronal dysfunction did not correlate with amyloid deposition. Our data are consistent with a model in which S-100B overexpression in AD enhances glial activation and leads to an augmented neuroinflammatory process that increases the severity of neuropathologic sequelae.
Craft
Jeffrey M
JM
Center for Drug Discovery and Chemical Biology, Northwestern University, Chicago, Illinois 60611-3008, USA.
Watterson
D Martin
DM
Marks
Alexander
A
Van Eldik
Linda J
LJ
D016229:Amyloid beta-Peptides / Q000633:toxicity*; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D001921:Brain / Q000187:drug effects / Q000378:metabolism* / Q000503:physiopathology; D004195:Disease Models, Animal; D004660:Encephalitis / Q000139:chemically induced / Q000235:genetics / Q000378:metabolism*; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D005911:Gliosis / Q000139:chemically induced / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007276:Injections, Intraventricular; D051379:Mice; D018345:Mice, Knockout; D008822:Mice, Transgenic; D009410:Nerve Degeneration / Q000139:chemically induced / Q000235:genetics / Q000378:metabolism; D009414:Nerve Growth Factors / Q000235:genetics*; D009474:Neurons / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D010446:Peptide Fragments / Q000633:toxicity*; D058225:Plaque, Amyloid / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D017729:Presynaptic Terminals / Q000378:metabolism / Q000473:pathology; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins / Q000235:genetics*; D014443:Tyrosine / Q000031:analogs & derivatives / Q000378:metabolism
D016229:Amyloid beta-Peptides; D015415:Biomarkers; D009414:Nerve Growth Factors; D010446:Peptide Fragments; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins; C075222:amyloid beta-protein (1-42); C002744:3-nitrotyrosine; D014443:Tyrosine