The TREM2-APOE Pathway Drives the Transcriptional Phenotype of Dysfunctional Microglia in Neurodegenerative Diseases

UMMS Affiliation

Department of Microbiology and Physiological Systems; Department of Biochemistry and Molecular Pharmacology; Program in Bioinformatics and Integrative Biology

Publication Date


Document Type



Biochemistry, Biophysics, and Structural Biology | Bioinformatics | Computational Biology | Immunology and Infectious Disease | Integrative Biology | Nervous System Diseases | Systems Biology


Microglia play a pivotal role in the maintenance of brain homeostasis but lose homeostatic function during neurodegenerative disorders. We identified a specific apolipoprotein E (APOE)-dependent molecular signature in microglia from models of amyotrophic lateral sclerosis (ALS), multiple sclerosis (MS), and Alzheimer's disease (AD) and in microglia surrounding neuritic beta-amyloid (Abeta)-plaques in the brains of people with AD. The APOE pathway mediated a switch from a homeostatic to a neurodegenerative microglia phenotype after phagocytosis of apoptotic neurons. TREM2 (triggering receptor expressed on myeloid cells 2) induced APOE signaling, and targeting the TREM2-APOE pathway restored the homeostatic signature of microglia in ALS and AD mouse models and prevented neuronal loss in an acute model of neurodegeneration. APOE-mediated neurodegenerative microglia had lost their tolerogenic function. Our work identifies the TREM2-APOE pathway as a major regulator of microglial functional phenotype in neurodegenerative diseases and serves as a novel target that could aid in the restoration of homeostatic microglia.


APOE, Alzheimer’s disease, TREM2, amyotrophic lateral sclerosis, microglia, multiple sclerosis, neurodegeneration, transcriptional regulation

DOI of Published Version



Immunity. 2017 Sep 19;47(3):566-581.e9. doi: 10.1016/j.immuni.2017.08.008. Link to article on publisher's site

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Full author list omitted for brevity. For the full list of authors, see article.

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