RRC ID 87295
Author Iguchi A, Takatori S, Kimura S, Muneto H, Wang K, Etani H, Ito G, Sato H, Hori Y, Sasaki J, Saito T, Saido TC, Ikezu T, Takai T, Sasaki T, Tomita T.
Title INPP5D modulates TREM2 loss-of-function phenotypes in a β-amyloidosis mouse model.
Journal iScience
Abstract The genetic associations of TREM2 loss-of-function variants with Alzheimer disease (AD) indicate the protective roles of microglia in AD pathogenesis. Functional deficiencies of TREM2 disrupt microglial clustering around amyloid β (Aβ) plaques, impair their transcriptional response to Aβ, and worsen neuritic dystrophy. However, the molecular mechanism underlying these phenotypes remains unclear. In this study, we investigated the pathological role of another AD risk gene, INPP5D, encoding a phosphoinositide PI(3,4,5)P3 phosphatase expressed in microglia. In a Tyrobp-deficient TREM2 loss-of-function mouse model, Inpp5d haplodeficiency restored the association of microglia with Aβ plaques, partially restored plaque compaction, and astrogliosis, and reduced phosphorylated tau+ dystrophic neurites. Mechanistic analyses suggest that TREM2/TYROBP and INPP5D exert opposing effects on PI(3,4,5)P3 signaling pathways as well as on phosphoproteins involved in the actin assembly. Our results suggest that INPP5D acts downstream of TREM2/TYROBP to regulate the microglial barrier against Aβ toxicity, thereby modulates Aβ-dependent pathological conversion of tau.
Volume 26(4)
Pages 106375
Published 2023-4-21
DOI 10.1016/j.isci.2023.106375
PII S2589-0042(23)00452-2
PMID 37035000
PMC PMC10074152
Resource
Mice RBRC06344