Dataset Information

Tau Kinetics in Neurons and the Human Central Nervous System.

ABSTRACT: We developed stable isotope labeling and mass spectrometry approaches to measure the kinetics of multiple isoforms and fragments of tau in the human central nervous system (CNS) and in human induced pluripotent stem cell (iPSC)-derived neurons. Newly synthesized tau is truncated and released from human neurons in 3 days. Although most tau proteins have similar turnover, 4R tau isoforms and phosphorylated forms of tau exhibit faster turnover rates, suggesting unique processing of these forms that may have independent biological activities. The half-life of tau in control human iPSC-derived neurons is 6.74 ± 0.45 days and in human CNS is 23 ± 6.4 days. In cognitively normal and Alzheimer's disease participants, the production rate of tau positively correlates with the amount of amyloid plaques, indicating a biological link between amyloid plaques and tau physiology.

SUBMITTER: Sato C

PROVIDER: S-EPMC6137722 | biostudies-literature | 2018 Mar

REPOSITORIES: biostudies-literature

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Tau Kinetics in Neurons and the Human Central Nervous System.

Sato Chihiro C Barthélemy Nicolas R NR Mawuenyega Kwasi G KG Patterson Bruce W BW Gordon Brian A BA Jockel-Balsarotti Jennifer J Sullivan Melissa M Crisp Matthew J MJ Kasten Tom T Kirmess Kristopher M KM Kanaan Nicholas M NM Yarasheski Kevin E KE Baker-Nigh Alaina A Benzinger Tammie L S TLS Miller Timothy M TM Karch Celeste M CM Bateman Randall J RJ

Neuron 20180301 6

We developed stable isotope labeling and mass spectrometry approaches to measure the kinetics of multiple isoforms and fragments of tau in the human central nervous system (CNS) and in human induced pluripotent stem cell (iPSC)-derived neurons. Newly synthesized tau is truncated and released from human neurons in 3 days. Although most tau proteins have similar turnover, 4R tau isoforms and phosphorylated forms of tau exhibit faster turnover rates, suggesting unique processing of these forms that ...[more]

PMID: 29566794

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Project description:Importance:Recent studies found that the concentration of amyloid-? (A?) fluctuates with the sleep-wake cycle. Although the amplitude of this day/night pattern attenuates with age and amyloid deposition, to our knowledge, the association of A? kinetics (ie, production, turnover, and clearance) with this oscillation has not been studied. Objective:To determine the association between A? kinetics, age, amyloid levels, and the A? day/night pattern in humans. Design, Setting, and Participants:We measured A? concentrations and kinetics in 77 adults aged 60 to 87 years with and without amyloid deposition by a novel precise mass spectrometry method at the Washington University School of Medicine in St Louis, Missouri. We compared findings of 2 orthogonal methods, enzyme-linked immunosorbent assay and mass spectrometry, to validate the day/night patterns and determine more precise estimates of the cosinor parameters. In vivo labeling of central nervous system proteins with stable isotopically labeled leucine was performed, and kinetics of A?40 and A?42 were measured. Interventions:Serial cerebrospinal fluid collection via indwelling lumbar catheter over 36 to 48 hours before, during, and after in vivo labeling, with a 9-hour primed constant infusion of 13C6-leucine. Main Outcomes and Measures:The amplitude, linear increase, and other cosinor measures of each participant's serial cerebrospinal fluid A? concentrations and A? turnover rates. Results:Of the 77 participants studied, 46 (59.7%) were men, and the mean (range) age was 72.6 (60.4-87.7) years. Day/night patterns in A? concentrations were more sharply defined by the precise mass spectrometry method than by enzyme-linked immunosorbent assay (mean difference of SD of residuals: A?40, -7.42 pM; P?<?.001; A?42, -3.72 pM; P?<?.001). Amyloid deposition diminished day/night amplitude and linear increase of A?42 but not of A?40. Increased age diminished day/night amplitude of both A?40 and A?42. After controlling for amyloid deposition, amplitude of A?40 was positively associated with production rates (r?=?0.42; P?<?.001), while the linear rise was associated with turnover rates (r?=?0.28; P?<?.05). The amplitude and linear rise of A?42 were both associated with turnover (r?=?-0.38; P?<?.001) and production (r?=?0.238; P?<?.05) rates. Conclusions and Relevance:Amyloid deposition is associated with premature loss of normal A?42 day/night patterns in older adults, suggesting the previously reported effects of age and amyloid on A?42 amplitude at least partially affect each other. Production and turnover rates suggest that day/night A? patterns are modulated by both production and clearance mechanisms active in sleep-wake cycles and that amyloid deposition may impair normal circadian patterns. These findings may be important for the designs of future secondary prevention trials for Alzheimer disease.

Dataset Information

Tau Kinetics in Neurons and the Human Central Nervous System.

Publications

Tau Kinetics in Neurons and the Human Central Nervous System.

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