Looking at the brain cells of
aging flies, they found that better glucose uptake compensates for age-related
deterioration in motor functions, and led to longer life. The effect was more
pronounced when coupled with dietary restrictions. This suggests healthier
eating plus improved glucose uptake in the brain might lead to enhanced
lifespans.
The brain is a particularly
power-hungry part of our bodies, consuming 20% of the oxygen we take in and 25%
of the glucose. That’s why it’s so important that it can stay powered, using
the glucose to produce adenosine triphosphate (ATP), the “energy courier” of
the body.
This chemical process, known
as glycolysis, happens in both the intracellular fluid and a part of cells
known as the mitochondria. But as we get older, our brain cells become less
adept at making ATP, something that broadly correlates with less glucose
availability. That might suggest that more food for more glucose might actually
be a good thing.
On the other hand, it is
known that a healthier diet actually leads to longer life. Unravelling the
mystery surrounding these two contradictory pieces of knowledge might lead to a
better understanding of healthier, longer lifespans.
A team led by Associate
Professor Kanae Ando studied this problem using Drosophila fruit flies.
Firstly, they confirmed that brain cells in older flies tended to have lower
levels of ATP, and lower uptake of glucose. They specifically tied this down to
lower amounts of the enzymes needed for glycolysis.
To counteract this effect,
they genetically modified flies to produce more of a glucose-transporting
protein called hGut3. Amazingly, this increase in glucose uptake was all that
was required to significantly improve the amount of ATP in cells. More
specifically, they found that more hGut3 led to less decrease in the production
of the enzymes, counteracting the decline with age.
Though this did not lead to
an improvement in age-related damage to mitochondria, they also suffered less
deterioration in locomotor functions.
But that’s not all. In a
further twist, the team put the flies with enhanced glucose uptake under
dietary restrictions, to see how the effects interact. Now, the flies had even
longer lifespans. Curiously, the increased glucose uptake did not actually
improve the levels of glucose in brain cells. The results point to the
importance of not just how much glucose there is, but how efficiently it is
used once taken into cells to make the energy the brain needs.
Though the anti-aging
benefits of a restricted diet have been shown in many species, the team were
able to combine this with improved glucose uptake to leverage the benefits of
both for even longer lifespans in a model organism. Further study may provide
vital clues to how we might keep our brains healthier for longer.
No comments:
Post a Comment