GSE169478
Chronic intermittent hypoxia enhances pathological tau seeding, propagation, and accumulation, and exacerbates Alzheimer's-like memory and synaptic plasticity deficits and molecular signatures
Obstructive sleep apnea (OSA), characterized by sleep fragmentation and chronic intermittenthypoxia (CIH), is a risk factor for Alzheimer's disease (AD) progression. Recent epidemiologicalstudies point to CIH as the best predictor of developing cognitive decline and AD in elderly withOSA. However, the precise underlying mechanism(s) remain unknown. The present study wasundertaken to evaluate the effect of CIH on pathological human tau seeding, propagation, andaccumulation, cognition, synaptic plasticity, neuronal network excitability, and gene expressionprofiles in a P301S human mutant tau mouse model of AD and related tauopathies. We exposed 4-4.5-month-old, male, P301S and WT mice to an 8-week CIH protocol (6 min cycle:21% O 2 to 8% O 2 to 21% O 2 , 80 cycles per 8 h during daytime), and assessed its effect on taupathology and various AD-related phenotypic and molecular signatures. Age- and gender-matched P301S and WT mice were reared in normoxia (21% O 2 ) as experimental controls. CIH significantly enhanced pathological human tau seeding and spread across connected brain circuitry in P301S mice; it also increased phospho-tau load. CIH also exacerbated memory and synaptic plasticity deficits in P301S mice. However, CIH had no effect on seizure susceptibility and network hyperexcitability in these mice. Finally, CIH exacerbated AD-related pathogenic molecular signaling in P301S mice. CIH-induced increase in pathologic human tau seeding and spread and exacerbation of other AD- related impairments provide new insights into the role of CIH and OSA in AD pathogenesis. Overall design: RNA-seq of WT Normoxia, WT Hypoxia, P301S Normoxia and P301S Hypoxia mice samples