Category: Health and Wellness
A protein long thought to be one of the body's supporting players has
quietly been taking a lead role in healthy eyesight, a discovery that
could rapidly lead to treatments for babies born before their eyes
are finished growing, University of Florida and Harvard Medical
School researchers have found.
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The finding, described in separate, back-to-back papers to be
published in Tuesday's (June 19) Proceedings of the National Academy
of Sciences, offers a new target for therapies for retinopathy of
prematurity, a potentially blinding disease that annually affects
about 15,000 babies.
In newborns with the disease, oxygen-starved areas of the retina
compensate by quickly growing new blood vessels. But these new
vessels are fragile and leaky.
"We've identified a protein that is part of the body's natural
defenses in oxygen-deprived conditions," said Dr. Maria B. Grant, a
professor of pharmacology and therapeutics at UF's College of
Medicine. "When babies are born before levels of this protein are
normal, blood vessels spread abnormally throughout the retina. But if
we can increase the protein to more normal levels in premature
babies, it should result in healthier blood vessel growth."
The protein - insulin-like growth factor binding protein-3, or
IGFBP-3 - was thought to exist exclusively to regulate insulin-like
growth factor-1, a molecular growth factor that is necessary for the
development of nerve, muscle, bone, liver, kidney, lung, eye and
other body tissues.
But in studies of mice and of human cells in cultures, scientists
from the Program in Stem Cell Biology and Regenerative Medicine at
UF's McKnight Brain Institute found that IGFBP-3 activates stem cells
and other reparative cells of the bone marrow and the lining of blood vessels.
Researchers from Harvard Medical School and the University of
Goteborg in Sweden arrive at essentially the same conclusion in
Tuesday's issue of PNAS, identifying the protein IGFBP-3 as a
promising therapeutic agent after analyzing data from mouse and human studies.
"This discovery has a big future in helping premature babies," said
Alexander V. Ljubimov, Ph.D., a professor of medicine at UCLA and
director of Ophthalmology Research Laboratories at Cedars-Sinai
Medical Center. "The idea is to administer this already clinically
available protein to premature babies to stabilize the existing
vessels in the retina, prevent their loss and block the compensatory
growth of new, aberrant vessels. Finding the right dose may enable
babies to cope with the first phases of their life without becoming blind."
Retinopathy of prematurity affects infants weighing less than 2.75
pounds who are born within the first 31 weeks of pregnancy, according
to the National Eye Institute. More than 1,000 require medical
treatment and about 500 become legally blind.
"The discovery has added credibility because independent research
groups took different approaches to show essentially the same thing,"
said Ljubimov, who was not involved in the research. "There is
independent confirmation from totally different research teams within
the same journal."
At UF, researchers infused IGFBP-3 into one eye of each of nine mice
before placing the animals into a high-oxygen chamber for five days.
When scientists compared vascular growth within the retinas, they
found blood vessels were closer to normal in eyes treated with IGFBP-3.
When UF scientists repeated the experiment in 18 mice treated with
bone marrow stem cells expressing IGFBP-3, they found the treated
eyes developed normally.
In addition to studies in mice, Harvard research collaborators in
Sweden examined infants with retinopathy of prematurity in a
prospective clinical study and found that the IGFBP-3 levels were
lower than those of healthy infants, further suggesting that the
protein helps prevent oxygen-induced blood vessel loss and promotes
healthy vascular regrowth.
"The implications for retinopathy are that IGFBP-3 appears to have
benefit in preventing vessel loss independent of insulin-like growth
factor-1 in both the mouse model of oxygen-induced retinopathy and in
infants with retinopathy of prematurity," said Dr. Lois E.H. Smith,
an associate professor of ophthalmology at Harvard Medical School and
senior author of the Harvard study. "Supplementation to increase
IGFBP-3 in premature infants at risk for ROP to normal levels in
utero may prove beneficial in this disease.
"Harvard Medical School researchers and collaborators at the
University of Goteborg are currently conducting a phase 1 clinical
study to evaluate the use of IGFBP-3 in combination with IGF-1 to
examine the effects on prevention of retinopathy in premature
infants, based on the clinical findings in our study," Smith said.
"This work suggests that both IGF-1 and IGFBP-3 acting independently
help prevent retinopathy."
http://www.physorg.com/news101397180.html
Very interesting research.
As a ROP baby myself, this article caught my interest.
Thanks for posting it.
Bob
It didn't say if this would work on someone years after their birth. At least there's hope.
interesting.
good article. First time I ever read about protein helping in this disease. Good thing is there is still research going on about ROP because at least in my case other diseases cropped up later in life so I have those added attractions along with ROP. Glad to hear there is hope out there for the kids.