(See insti-uctions): Most neurodegenerative diseases, including Alzheimer's disease (AD), are disorders of protein aggregation in which specific proteins that are normally soluble, aggregate in the intra or extracellular space of the brain. In AD, a key factor that regulates whether an aggregation prone protein goes on to misfold is its concentration. Studies have shown that synaptic activity due to both presynaptic arid postsynaptic factors is coupled with the neuronal release of amyloid-B (AB). This suggests that understanding how integrated synaptic and network activity regulate both AB and potentially other proteins involved in neurodegenerative disease, may provide novel insights into pathogenesis. We found that in the brain interstitial fluid of mice (ISF), AP levels are dynamically and positively associated with the number of minutes awake per hour. Pharmacological studies showed that exogenous and endogenous orexin modulates both wakefulness and AB levels. Chronic sleep deprivation markedly increased and an orexin-receptor antagonist decreased AB deposition in APP Tg mouse models. Our preliminary data show that in ISF AB levels as well as measures of brain metabolic/synaptic activity predict how much AB deposition will occur in specific brain regions. Based on these results, we hypothesize that differences in brain metabolic/synaptic activity between brain regions regulate ISF AB levels and that the sleep/wake state regulates both soluble AB levels and ultimately AB deposition via effects on synaptic activity.
The specific aims are: 1) To dynamically measure the levels of ISF AB, molecules linked with synaptic activity such as lactate, molecules controlling wakefulness (orexin), and sleep (growth hormone releasing hormone-GHRH) by in vivo microdialysis in different brain regions with aging. 2) To determine the effects of genetic and pharmacological manipulation of orexin and GHRH signaling as well as effects of endogenous NMDA receptor activation, ERK signaling, and LRP1 on ISF AB fluctuations and the sleep/wake cycle in collaboration with projects 2 and 3. 3) To determine the relationship between mean sleep/wake time, other sleep features, and AD biomarkers (amyloid imaging, CSF AB and tau) in an ongoing study of cognitively normal humans (the adult children study) 45-75 years of age.

Public Health Relevance

Alzheimer's disease (AD) is the most common cause of dementia. There is no effective treatment that slows the progression of the disease. This project will assist in uncovering the relationship between normal processing of information in the brain (syaptic activity), the sleep/wake cycle, and the onset of AD changes in the brain. It has the possibility of revealing new potential avenues for treatment.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Program Projects (P01)
Project #
1P01NS074969-01A1
Application #
8331629
Study Section
National Institute of Neurological Disorders and Stroke Initial Review Group (NSD)
Project Start
2012-05-15
Project End
2017-04-30
Budget Start
2012-05-15
Budget End
2013-04-30
Support Year
1
Fiscal Year
2012
Total Cost
$298,400
Indirect Cost
$102,084
Name
Washington University
Department
Type
DUNS #
068552207
City
Saint Louis
State
MO
Country
United States
Zip Code
63130
Liu, Chia-Chen; Zhao, Na; Yamaguchi, Yu et al. (2016) Neuronal heparan sulfates promote amyloid pathology by modulating brain amyloid-β clearance and aggregation in Alzheimer's disease. Sci Transl Med 8:332ra44
Fisher, Jonathan R; Wallace, Clare E; Tripoli, Danielle L et al. (2016) Redundant Gs-coupled serotonin receptors regulate amyloid-β metabolism in vivo. Mol Neurodegener 11:45
Yamazaki, Yu; Baker, Darren J; Tachibana, Masaya et al. (2016) Vascular Cell Senescence Contributes to Blood-Brain Barrier Breakdown. Stroke 47:1068-77
Tachibana, Masaya; Shinohara, Mitsuru; Yamazaki, Yu et al. (2016) Rescuing effects of RXR agonist bexarotene on aging-related synapse loss depend on neuronal LRP1. Exp Neurol 277:1-9
Shinohara, Mitsuru; Kanekiyo, Takahisa; Yang, Longyu et al. (2016) APOE2 eases cognitive decline during Aging: Clinical and preclinical evaluations. Ann Neurol :
Sakae, Nobutaka; Liu, Chia-Chen; Shinohara, Mitsuru et al. (2016) ABCA7 Deficiency Accelerates Amyloid-β Generation and Alzheimer's Neuronal Pathology. J Neurosci 36:3848-59
Yuede, Carla M; Lee, Hyo; Restivo, Jessica L et al. (2016) Rapid in vivo measurement of β-amyloid reveals biphasic clearance kinetics in an Alzheimer's mouse model. J Exp Med 213:677-85
Ju, Yo-El S; Finn, Mary Beth; Sutphen, Courtney L et al. (2016) Obstructive sleep apnea decreases central nervous system-derived proteins in the cerebrospinal fluid. Ann Neurol 80:154-9
Shinohara, Mitsuru; Murray, Melissa E; Frank, Ryan D et al. (2016) Impact of sex and APOE4 on cerebral amyloid angiopathy in Alzheimer's disease. Acta Neuropathol 132:225-34
Fu, Yuan; Zhao, Jing; Atagi, Yuka et al. (2016) Apolipoprotein E lipoprotein particles inhibit amyloid-β uptake through cell surface heparan sulphate proteoglycan. Mol Neurodegener 11:37

Showing the most recent 10 out of 59 publications