APOE genotype regulates pathology and disease progression in synucleinopathy.

ABSTRACT: Apolipoprotein E (APOE) ?4 genotype is associated with increased risk of dementia in Parkinson's disease (PD), but the mechanism is not clear, because patients often have a mixture of ?-synuclein (?Syn), amyloid-? (A?), and tau pathologies. APOE ?4 exacerbates brain A? pathology, as well as tau pathology, but it is not clear whether APOE genotype independently regulates ?Syn pathology. In this study, we generated A53T ?Syn transgenic mice (A53T) on Apoe knockout (A53T/EKO) or human APOE knockin backgrounds (A53T/E2, E3, and E4). At 12 months of age, A53T/E4 mice accumulated higher amounts of brainstem detergent-insoluble phosphorylated ?Syn compared to A53T/EKO and A53T/E3; detergent-insoluble ?Syn in A53T/E2 mice was undetectable. By immunohistochemistry, A53T/E4 mice displayed a higher burden of phosphorylated ?Syn and reactive gliosis compared to A53T/E2 mice. A53T/E2 mice exhibited increased survival and improved motor performance compared to other APOE genotypes. In a complementary model of ?Syn spreading, striatal injection of ?Syn preformed fibrils induced greater accumulation of ?Syn pathology in the substantia nigra of A53T/E4 mice compared to A53T/E2 and A53T/EKO mice. In two separate cohorts of human patients with PD, APOE ?4/?4 individuals showed the fastest rate of cognitive decline over time. Our results demonstrate that APOE genotype directly regulates ?Syn pathology independent of its established effects on A? and tau, corroborate the finding that APOE ?4 exacerbates pathology, and suggest that APOE ?2 may protect against ?Syn aggregation and neurodegeneration in synucleinopathies.

SUBMITTER: Davis AA 

PROVIDER: S-EPMC7289511 | biostudies-literature | 2020 Feb

REPOSITORIES: biostudies-literature