Research Institute of the MUHC/McGill University study proves that muscle atrophy in cystic fibrosis patients is genetic in origin.
Research Institute of the MUHC/McGill University study
proves that muscle atrophy in cystic fibrosis patients is genetic
in origin.
Patients with cystic fibrosis (CF) usually experience
significant muscle loss, a symptom traditionally considered to be a
secondary complication of the devastating genetic disease. However,
a recent study by Dr. Basil Petrof reverses the equation: his
results show that muscle atrophy and weakness may be a primary
symptom caused by the effects of CFTR gene mutations on the muscle
itself. Dr. Petrof’s findings will be published on July 31 in
Public Library of Science – Genetics.
Cystic fibrosis is known to be caused by a specific mutation on
the CFTR gene. Dr. Petrof’s study demonstrates for the first time
that the CFTR gene is also present in skeletal muscles, where it
plays a role in calcium regulation.
“After analyzing our results, we believe that defects in the
CFTR gene are directly involved in the skeletal muscle wasting and
weakness seen in many CF patients,” Dr. Petrof explained. “And in
the specific case of the diaphragm, a muscle required for
breathing, this can potentially lead to fatal respiratory failure
when the lungs are infected.”
The researchers’ data also show that lung infection and
increased inflammation in the body are major triggers which
interact with the genetic mutation to cause muscle atrophy and
weakness in CF mice. These results are also applicable to
humans.
“Our study suggests that one way to fight CF-related muscle
atrophy is to aggressively control inflammation and infection in
our patients. In fact”, continued Dr. Petrof, “this is what current
treatments already try to do; we simply need to reinforce them. In
addition, our study suggests that a new way to treat the problem in
the future may be to use drugs which can prevent an excess calcium
build-up in their muscle cells.”
These new findings run contrary to the traditional belief that
muscle atrophy in CF patients is simply the consequence of a lack
of exercise or poor nutrient absorption. Although these
explanations undoubtedly play a role in some patients, it now
appears that a primary cause of the muscle loss could actually be
genetic in origin. This new evidence that the CFTR gene plays a
role in skeletal muscle could help researchers to develop novel
therapies for improving the function of the diaphragm and other
muscles in CF patients.
CF is a genetic disease caused by mutations in the CFTR gene.
This gene is involved in the movement of chloride and other ions
across cell membranes; its mutation causes a thickening of
secretions in the lungs and other organs. In the lungs, these
thicker secretions clog and block air passages which promote
respiratory infections.
Dr. Basil Petrof
Dr. Basil Petrof is the Associate Director of the
Meakins-Christie Laboratories, in the Respiratory Health
Axis of the Research Institute of the MUHC. He also practices
respiratory medicine at the McGill University Health Centre and is
a Professor of Medicine at McGill University.
Funding
This study was funded by the Canadian Cystic Fibrosis
Foundation, the Canadian Institutes of Health Research and BREATHE
program, the Quebec Respiratory Health Network of the Fonds de la
recherche en santé du Québec (FRSQ), and a Chercheur National Award
from the FRSQ to Dr. Basil Petrof.
Partners
This article was co-authored by Dr. Maziar Divangahi, Dr.
Haouaria Balghi (co-first authors), Dr. Gawiyou Danialou, Dr. Alain
Comtois, Dr. Alexandre Demoule, Dr. Sheila Ernest, Dr. Christina
Haston, Dr. Danuta Radzioch and Dr. Basil Petrof of the Research
Institute of the MUHC, as well as by Dr. Renaud Robert and Dr. John
W. Hanrahan of McGill University.
The Research Institute of the McGill University Health
Centre (RI MUHC) is a world-renowned biomedical and
health-care hospital research centre. Located in Montreal, Quebec,
the Institute is the research arm of the MUHC, the university
health centre affiliated with the Faculty of Medicine at McGill
University. The Institute supports over 600 researchers, nearly
1200 graduate and post-doctoral students and operates more than 300
laboratories devoted to a broad spectrum of fundamental and
clinical research. The Research Institute operates at the forefront
of knowledge, innovation and technology and is inextricably linked
to the clinical programs of the MUHC, ensuring that patients
benefit directly from the latest research-based knowledge.
The Research Institute of the MUHC is supported in part by the
Fonds de la recherche en santé du Québec.
For further details visit: www.muhc.ca/research.
About McGill University
McGill University, founded in Montreal, Que., in 1821, is
Canada’s leading post-secondary institution. It has two campuses,
11 faculties, 10 professional schools, 300 programs of study and
more than 34,000 students. McGill attracts students from more than
160 countries around the world. Almost half of McGill students
claim a first language other than English – including 6,000
francophones – with more than 6,400 international students making
up almost 20 per cent of the student body.