Ayuh, ikut jogging...
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Web address:
http://www.sciencedaily.com/releases/2012/01/
120111133520.htm
Boost for Health? Researchers Isolate Protein Linking Exercise to Health
Benefits
A team led by researchers at Dana-Farber Cancer Institute has isolated a
natural hormone from muscle cells that triggers some of the key health benefits
of exercise. (Credit: © Imre Forgo / Fotolia)
ScienceDaily (Jan. 11, 2012) A team led by researchers at Dana-Farber Cancer
Institute has isolated a natural hormone from muscle cells that triggers some
of the key health benefits of exercise. They say the protein, which serves as a
chemical messenger, is a highly promising candidate for development as a novel
treatment for diabetes, obesity and perhaps other disorders, including cancer.
Bruce Spiegelman, PhD, a cell biologist at Dana-Farber, is senior author of the
report, posted as an advanced online publication by the journal Nature. The
first author is Pontus Bostroöm, MD, PhD, a postdoctoral fellow in the
Spiegelman lab.
"It's exciting to find a natural substance connected to exercise that has such
clear therapeutic potential," said Bostroöm.
Spiegelman dubbed the hormone "irisin," after Iris, a Greek messenger goddess.
He said the discovery is an important first step in understanding the
biological mechanisms that translate physical exercise into beneficial changes
throughout the body, both in healthy people and in preventing or treating
disease.
"There has been a feeling in the field that exercise 'talks to' various tissues
in the body," said Spiegelman, a professor of cell biology at Harvard Medical
School. "But the question has been, how?"
According to the report, the irisin hormone has direct and "powerful effects"
on adipose, or fatty, tissue -- subcutaneous deposits of white fat that store
excess calories and which contribute to obesity.
When irisin levels rise through exercise -- or, in this study, when irisin was
injected into mice -- the hormone switches on genes that convert white fat into
"good" brown fat. This is beneficial because brown fat burns off more excess
calories than does exercise alone.
Only a small amount of brown fat is found in adults, but infants have more --
an evolutionary echo of how mammals keep themselves warm while hibernating. In
the wake of findings by Spiegelman and others, there has been a surge of
interest in the therapeutic possibilities of increasing brown fat in adults.
Along with stimulating brown fat development, irisin was shown to improve
glucose tolerance, a key measure of metabolic health, in mice fed a high-fat
diet.
The discovery won't allow people will be able to skip the gym and build muscles
by taking irisin supplements, Spiegelman cautioned, because the hormone doesn't
appear to make muscles stronger. Experiments showed that irisin levels increase
as a result of repeated bouts of prolonged exercise, but not during short-term
muscle activity.
The Dana-Farber team identified irisin in a search for genes and proteins
regulated by a master metabolic regulator, called PGC1-alpha, that is turned on
by exercise. Spiegelman's group had discovered PGC1-alpha in previous research.
Bostroöm said the hunt for molecular targets of increased PGC1-alpha activity
ultimately pinpointed irisin, which turned out to be located within the outer
membrane of muscle cells. This discovery ran counter to other scientists'
contentions that such a protein would reside in the cell's nucleus.
To test whether increasing irisin alone could mimic exercise benefits, the
scientists injected modest amounts into sedentary mice that were obese and
pre-diabetic.
With 10 days of treatment, the mice had better control of blood sugar and
insulin levels -- in effect, preventing the onset of diabetes -- and lost a
small amount of weight. Although the weight loss was small, Spiegelman said
that the hormone may have a greater effect when given for longer periods.
There were no signs of toxicity or side effects, which was predicted since the
researchers limited the increase of irisin to levels typically caused by
exercise.
In part because it is a natural substance and because the mouse and human forms
of the protein are identical, Spiegelman said it should be possible to move an
irisin-based drug rapidly into clinical testing -- perhaps within two years.
The irisin discovery has been licensed by Dana-Farber exclusively to Ember
Therapeutics for drug development. Ember is a Boston-based startup co-founded
by Spiegelman and scientists at the Joslin Diabetes Center and the Scripps
Research Institute in Florida.
The scientists said their findings merely scratch the surface of irisin's
multiple effects. They are continuing to explore the hormone's possible
benefits in metabolic diseases like diabetes, insulin resistance, and obesity,
which constitute a growing epidemic around the world, as well as
neurodegenerative illnesses like Parkinson's disease.
Spiegelman added that as growing evidence implicates obesity and physical
inactivity in cancer development, it's conceivable irisin-based drugs may have
value in prevention and treatment of the disease.
Other authors, in addition to Spiegelman and Boström, are from
Dana-Farber; Harvard Medical School; Brigham and Women's Hospital; University
of California at San Francisco; Universita Politecnica delle Marche, Ancona,
Italy; Odense University Hospital, Denmark; and LakePharma, Belmont, Calif.
The National Institutes of Health funded the research.
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Story Source:
The above story is reprinted from materials provided by Dana-Farber Cancer
Institute.
Note: Materials may be edited for content and length. For further
information, please contact the source cited above.
Journal Reference:
Pontus Boström, Jun Wu, Mark P. Jedrychowski, Anisha Korde, Li Ye, James C.
Lo, Kyle A. Rasbach, Elisabeth Almer Boström, Jang Hyun Choi, Jonathan Z. Long,
Shingo Kajimura, Maria Cristina Zingaretti, Birgitte F. Vind, Hua Tu, Saverio
Cinti, Kurt Højlund, Steven P. Gygi, Bruce M. Spiegelman. A
PGC1-α-dependent myokine that drives brown-fat-like development of white
fat and thermogenesis. Nature, 2012; DOI: 10.1038/nature10777
Need to cite this story in your essay, paper, or report? Use one of the
following formats:
APA
MLA
Dana-Farber Cancer Institute (2012, January 11). Boost for health? Researchers
isolate protein linking exercise to health benefits. ScienceDaily. Retrieved
January 18, 2012, from http://www.sciencedaily.com
/releases/2012/01/120111133520.htm
Note: If no author is given, the source is cited instead.
Disclaimer: This article is not intended to provide medical advice, diagnosis
or treatment. Views expressed here do not necessarily reflect those of
ScienceDaily or its staff.
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