Brain energy metabolism is optimized to minimize the cost of enzyme synthesis and transport

The energy metabolism of the brain is poorly understood partly due to the complex morphology of neurons and fluctuations in ATP demand over time. To investigate this, we used metabolic models that estimate enzyme usage per pathway, enzyme utilization over time, and enzyme transportation to evaluate how these parameters and processes affect ATP costs for enzyme synthesis and transportation. Our models show that the total enzyme maintenance energy expenditure of the human body depends on how glycolysis and mitochondrial respiration are distributed both across and within cell types in the brain. We suggest that brain metabolism is optimized to minimize the ATP maintenance cost by distributing the different ATP generation pathways in an advantageous way across cell types and potentially also across synapses within the same cell. Our models support this hypothesis by predicting export of lactate from both neurons and astrocytes during peak ATP demand, reproducing results from experimental measurements reported in the literature. Furthermore, our models provide potential explanation for parts of the astrocyte-neuron lactate shuttle theory, which is recapitulated under some conditions in the brain, while contradicting other aspects of the theory. We conclude that enzyme usage per pathway, enzyme utilization over time, and enzyme transportation are important factors for defining the optimal distribution of ATP production pathways, opening a broad avenue to explore in brain metabolism.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:121

Enthalten in:

Proceedings of the National Academy of Sciences of the United States of America - 121(2024), 7 vom: 13. Feb., Seite e2305035121

Sprache:

Englisch

Beteiligte Personen:

Gustafsson, Johan [VerfasserIn]
Robinson, Jonathan L [VerfasserIn]
Zetterberg, Henrik [VerfasserIn]
Nielsen, Jens [VerfasserIn]

Links:

Volltext

Themen:

33X04XA5AT
8L70Q75FXE
ANLS
Adenosine Triphosphate
Brain metabolism
Genome-scale models
Glucose
IY9XDZ35W2
Journal Article
Lactic Acid
Mathematical modeling
Metabolism

Anmerkungen:

Date Completed 07.02.2024

Date Revised 19.02.2024

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1073/pnas.2305035121

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM368051048