APOE4, Age, and Sex Regulate Respiratory Plasticity Elicited by Acute Intermittent Hypercapnic-Hypoxia

© The Author(s) 2023. Published by Oxford University Press on behalf of American Physiological Society..

Rationale: Acute intermittent hypoxia (AIH) shows promise for enhancing motor recovery in chronic spinal cord injuries and neurodegenerative diseases. However, human trials of AIH have reported significant variability in individual responses.

Objectives: Identify individual factors (eg, genetics, age, and sex) that determine response magnitude of healthy adults to an optimized AIH protocol, acute intermittent hypercapnic-hypoxia (AIHH).

Methods: In 17 healthy individuals (age = 27 ± 5 yr), associations between individual factors and changes in the magnitude of AIHH (15, 1-min O2 = 9.5%, CO2 = 5% episodes) induced changes in diaphragm motor-evoked potential (MEP) amplitude and inspiratory mouth occlusion pressures (P0.1) were evaluated. Single nucleotide polymorphisms (SNPs) in genes linked with mechanisms of AIH induced phrenic motor plasticity (BDNF, HTR2A, TPH2, MAOA, NTRK2) and neuronal plasticity (apolipoprotein E, APOE) were tested. Variations in AIHH induced plasticity with age and sex were also analyzed. Additional experiments in humanized (h)ApoE knock-in rats were performed to test causality.

Results: AIHH-induced changes in diaphragm MEP amplitudes were lower in individuals heterozygous for APOE4 (i.e., APOE3/4) compared to individuals with other APOE genotypes (P = 0.048) and the other tested SNPs. Males exhibited a greater diaphragm MEP enhancement versus females, regardless of age (P = 0.004). Additionally, age was inversely related with change in P0.1 (P = 0.007). In hApoE4 knock-in rats, AIHH-induced phrenic motor plasticity was significantly lower than hApoE3 controls (P < 0.05).

Conclusions: APOE4 genotype, sex, and age are important biological determinants of AIHH-induced respiratory motor plasticity in healthy adults.

Addition to Knowledge Base: AIH is a novel rehabilitation strategy to induce functional recovery of respiratory and non-respiratory motor systems in people with chronic spinal cord injury and/or neurodegenerative disease. Figure 5 Since most AIH trials report considerable inter-individual variability in AIH outcomes, we investigated factors that potentially undermine the response to an optimized AIH protocol, AIHH, in healthy humans. We demonstrate that genetics (particularly the lipid transporter, APOE), age and sex are important biological determinants of AIHH-induced respiratory motor plasticity.

Errataetall:

UpdateOf: bioRxiv. 2023 Jan 07;:. - PMID 36711653

Medienart:

E-Artikel

Erscheinungsjahr:

2023

Erschienen:

2023

Enthalten in:

Zur Gesamtaufnahme - volume:4

Enthalten in:

Function (Oxford, England) - 4(2023), 5 vom: 09., Seite zqad026

Sprache:

Englisch

Beteiligte Personen:

Nair, Jayakrishnan [VerfasserIn]
Welch, Joseph F [VerfasserIn]
Marciante, Alexandria B [VerfasserIn]
Hou, Tingting [VerfasserIn]
Lu, Qing [VerfasserIn]
Fox, Emily J [VerfasserIn]
Mitchell, Gordon S [VerfasserIn]

Links:

Volltext

Themen:

APOE4
Age
ApoE protein, human
Apolipoprotein E4
Biomarkers
Genetics
Intermittent hypercapnic-hypoxia
Journal Article
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.
Respiratory neuroplasticity
Sex

Anmerkungen:

Date Completed 15.08.2023

Date Revised 29.03.2024

published: Electronic-eCollection

UpdateOf: bioRxiv. 2023 Jan 07;:. - PMID 36711653

Citation Status MEDLINE

doi:

10.1093/function/zqad026

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM360748732