Differential effects of partial and complete loss of TREM2 on microglial injury response and tauopathy.

TitleDifferential effects of partial and complete loss of TREM2 on microglial injury response and tauopathy.
Publication TypeJournal Article
Year of Publication2018
AuthorsSayed FA, Telpoukhovskaia M, Kodama L, Li Y, Zhou Y, Le D, Hauduc A, Ludwig C, Gao F, Clelland C, Zhan L, Cooper YA, Davalos D, Akassoglou K, Coppola G, Gan L
JournalProc Natl Acad Sci U S A
Volume115
Issue40
Pagination10172-10177
Date Published2018 10 02
ISSN1091-6490
KeywordsAging, Alzheimer Disease, Animals, Haploinsufficiency, Hemizygote, Membrane Glycoproteins, Mice, Mice, Knockout, Microglia, Mutation, Missense, Receptors, Immunologic
Abstract

Alzheimer's disease (AD), the most common form of dementia, is characterized by the abnormal accumulation of amyloid plaques and hyperphosphorylated tau aggregates, as well as microgliosis. Hemizygous missense variants in Triggering Receptor Expressed on Myeloid Cells 2 () are associated with elevated risk for developing late-onset AD. These variants are hypothesized to result in loss of function, mimicking TREM2 haploinsufficiency. However, the consequences of TREM2 haploinsufficiency on tau pathology and microglial function remain unknown. We report the effects of partial and complete loss of TREM2 on microglial function and tau-associated deficits. In vivo imaging revealed that microglia from aged TREM2-haploinsufficient mice show a greater impairment in their injury response compared with microglia from aged TREM2-KO mice. In transgenic mice expressing mutant human tau, TREM2 haploinsufficiency, but not complete loss of TREM2, increased tau pathology. In addition, whereas complete TREM2 deficiency protected against tau-mediated microglial activation and atrophy, TREM2 haploinsufficiency elevated expression of proinflammatory markers and exacerbated atrophy at a late stage of disease. The differential effects of partial and complete loss of TREM2 on microglial function and tau pathology provide important insights into the critical role of TREM2 in AD pathogenesis.

DOI10.1073/pnas.1811411115
Alternate JournalProc. Natl. Acad. Sci. U.S.A.
PubMed ID30232263
PubMed Central IDPMC6176614
Grant ListT32 GM007618 / GM / NIGMS NIH HHS / United States
R35 NS097976 / NS / NINDS NIH HHS / United States
P30 NS062691 / NS / NINDS NIH HHS / United States
R01 AG051390 / AG / NIA NIH HHS / United States
R01 AG054214 / AG / NIA NIH HHS / United States
F31 AG058505 / AG / NIA NIH HHS / United States