Cover Story

Glucose is the main energy substrate for the brain, which accounts for about 20% of whole-body glucose utilization. Glucose is metabolized in cells either by glycolysis or the pentose phosphate pathway (PPP). In the glycolytic pathway, glucose is converted to pyruvate which can be converted to lactate or sent to the tricarboxylic acid (TCA) cycle to generate ATP via oxidative phosphorylation. Alternatively, glucose can enter the PPP to generate 5-carbon sugars, as well as NADPH, which is a cofactor for cholesterol biosynthesis and protects against oxidative stress. Though each cell can use glucose for either glycolysis or the PPP, different cell populations favor distinct metabolic pathways. For example, oligodendrocytes shuttle more glucose into the PPP in order to generate NADPH for cholesterol biosynthesis, which is then used to build up myelin sheaths.

To investigate the regional fate of glucose, Kleinridders, Ferris, Reyzer et al. assessed multiple steps within the glycolytic pathway and PPP using a combination of gene and protein expression, protein activity assays, and imaging mass spectrometry (IMS). They demonstrate that while measurements of enzyme expression and activity point to differences in the regional activity of glycolysis and the PPP, IMS provides a direct measurement of the metabolites generated in these pathways in specific brain regions, including those which are otherwise difficult to assess, such as the fimbria or corpus callosum. Further, they show that in these highly myelinated white matter tracts there is a high ATP/ADP ratio but not a similarly high hexose bisphosphate/hexose monophosphate ratio, supporting the notion that the lactate shuttle may be very important for energy metabolism in these brain regions.

Full Text
The 60 Second Metabolist
In this section authors briefly report on their work recently published in Molecular Metabolism.

Watch the most recent interview by clicking the video still. The link "referring article" directs you to this author's publication.

Anne White, Jonathan Wray, Erika Harno
University of Manchester, UK
Referring article

Other Scientists...
Issue Alert
If you want to be alerted via email when new content that matches your interests is available, please login or register at
Conferences & Events
25 − 30
Epigenomics, Nuclear Receptors and Disease
Spetses Island, Greece
9 − 12
Ageing and Regeneration
Innsbruck, Austria
23 − 25
7th Helmholtz Diabetes Conference
Munich, Germany
15 − 18
Nature Conference: Advances in Metabolic Communication
Rio de Janeiro, Brasil
15 − 18
13th European Nutrition Conference
Dublin, Ireland
27 − 31
Metabolism in Action
Hillerod, Denmark
6 − 8
Cachexia, Sarcopenia and Muscle Wasting
Berlin, Germany
Media Coverage
Supported by