Getting oxygenated blood to exercising muscles
Date:
August 11, 2021
Source:
ETH Zurich
Summary:
Researchers have discovered a certain type of blood vessel cell in
muscles that multiplies rapidly upon exercise, thereby forming new
blood vessels. Researchers can use this to find novel therapies
for vascular disorders of the muscle.
FULL STORY ========================================================================== Researchers have discovered a certain type of blood vessel cell in muscles
that multiplies rapidly upon exercise, thereby forming new blood vessels.
Researchers can use this to find novel therapies for vascular disorders
of the muscle.
==========================================================================
"In industrialised countries, the leading cause of surgeons having to
amputate a foot or leg is impaired vascular supply to the muscles of
diabetic patients," Katrien De Bock says. As Professor for Exercise
and Health at ETH Zurich, she and her team study how to treat vascular disorders of the muscles and how new blood vessels form. It's common
knowledge that exercise and sport stimulate the formation of blood
vessels. By contrast, very little is known about the underlying molecular
and cellular mechanisms. "Once we understand these mechanisms, we can
work towards systematically improving the blood supply of patients'
muscles," De Bock says.
In mice and using cultured human cells, De Bock and her colleagues have
now investigated how exercise promotes the formation of thin blood
capillaries in the muscle in healthy subjects. Turning the spotlight
onto the cells of the vascular wall (known as endothelial cells),
they discovered that there are two capillary endothelial cell types,
which can be distinguished by the molecular marker ATF4. It turns out
that cells with very little ATF4 are mainly found in the capillaries
supplying the white muscle fibres, while cells with high levels of ATF4 primarily form part of the blood vessels close to red muscle fibres.
Ready to go Moreover, the scientists demonstrated that exercise
predominantly stimulates cell division of endothelial cells with high
levels of ATF4 (those near red muscle fibres), leading to the formation of
new capillaries. By contrast, exercise does not elicit a direct response
in cells with very little ATF4.
"Endothelial cells with high levels of ATF4 are on 'metabolic standby
mode', always ready to start forming new vessels," De Bock says. ATF4
is a regulatory protein inside the cell. Cells with this protein are
primed to quickly respond to the appropriate stimulus. As soon as a
person -- or, in this case, a mouse - - starts exercising, these cells
increase their amino acid intake and accelerate the formation of DNA and proteins, encouraging rapid cell proliferation. This ultimately leads
to the formation of new blood vessels.
Why these 'ready to go' endothelial cells are mainly found near red
muscle fibres is not yet known. The researchers intend to unravel this
mystery next.
In addition, the scientists hope to use these findings to develop
therapies that stimulate the growth of muscular blood vessels in patients suffering from diabetes or arterial occlusions and in organ transplant recipients.
========================================================================== Story Source: Materials provided by ETH_Zurich. Original written by
Fabio Bergamin. Note: Content may be edited for style and length.
========================================================================== Journal Reference:
1. Zheng Fan, Guillermo Turiel, Raphaela Ardicoglu, Moheb Ghobrial, Evi
Masschelein, Tea Kocijan, Jing Zhang, Ge Tan, Gillian Fitzgerald,
Tatiane Gorski, Abdiel Alvarado-Diaz, Paola Gilardoni, Christopher
M. Adams, Bart Ghesquie`re, Katrien De Bock. Exercise-induced
angiogenesis is dependent on metabolically primed ATF3/4 endothelial
cells. Cell Metabolism, 2021; DOI: 10.1016/j.cmet.2021.07.015 ==========================================================================
Link to news story:
https://www.sciencedaily.com/releases/2021/08/210811131549.htm
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