Yeast is helping to tackle the root cause of cystic fibrosis – a disease that results
from faulty ion channels. A new study shows how a small molecule can take the place of a missing
protein in yeast cells with faulty ion channels, enabling them to work again.
Most cases of cystic fibrosis are diagnosed by the age of 2.
The study, by researchers from the University of Illinois at Urbana-Champaign, is published in
the Journal of the American Chemical Society.
All organisms – from microbes to humans – rely on protein pumps and channels that transport ions
across the cell membrane. Faulty ion channels in cells underlie many currently incurable human
diseases.
Cystic fibrosis is caused by a genetic mutation that affects some of the proteins that
make up ion channels, causing them to malfunction. The result is a thick build up of mucus in the
lungs and other organs, making breathing difficult.
While treatments for cystic fibrosis exist, they do not fix the underlying cause. Treatments
include inhalants, enzyme supplements and clearing the airways, which can usually only be done
with help.
Yeast is a useful organism for researching human health and disease because yeast cells are
very similar to human cells. On two occasions, yeast has featured in studies that have won Nobel
prizes (one in 2001, the other in 2009) for their work on human cells.
The new study describes how a small molecule can take the place of a missing protein
to restore the type of ion channel function that is missing in people with cystic fibrosis and
similar diseases. The molecule – amphotericin B – was originally extracted from bacteria and is used to
treat fungal infections.
The small molecule caused deficient yeast to grow nearly as well as normal yeast
The team tested the small molecule at low doses in a strain of yeast that cannot grow because
it has faulty ion channels.
Fast facts about cystic fibrosis
- People with cystic fibrosis have inherited two copies of the defective CF gene
- About 70,000 people worldwide are living with cystic fibrosis
- Most cases are diagnosed by the age of 2.
Learn more about cystic fibrosis
When they added the molecule, the researchers found the yeast grew nearly as well as a normal
strain that they used as a control. They note:
“Here we report vigorous and sustainable restoration of yeast cell growth by
replacing missing protein ion transporters with imperfect small molecule
mimics.”
The authors say more research is needed to confirm whether the small molecule will work in
human diseases like cystic fibrosis. In the meantime, however, they conclude that their study provides a “framework for
pursuing such a therapeutic strategy.”
People with cystic fibrosis are at greater risk of lung infection because the thick, sticky
mucus that builds up in the lungs allows germs to thrive and multiply.
Earlier this year, Medical News Today reported how researchers are reaching a better
understanding of infections in cystic fibrosis. A small study
of children with the disease reveals that the microorganisms that infect people with cystic
fibrosis can survive on little to no oxygen.
Written by Catharine Paddock PhD
Copyright: Medical News Today
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