Researcher to Study Astronaut Bone Loss for Space Biology Agency (Forwarded)

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FOR IMMEDIATE RELEASE: Monday, February 12, 2007

Researcher to Study Astronaut Bone Loss for Space Biology Agency

Roger K. Long, MD, an endocrinology research fellow at the San Francisco VA
Medical Center and the University of California, San Francisco, was one of
only three scientists named in January 2007 as 2006-2008 Postdoctoral
Fellows by the National Space Biomedical Research Institute (NSBRI).

Long's NSBRI research project will focus on the causes and possible methods
of treating or preventing bone loss resulting from the prolonged
weightlessness of space travel.

The research also has great relevance for patients on Earth who are
immobilized for long periods -- paraplegics, quadriplegics, and people in
casts, says Long's mentor for the project, SFVAMC staff physician Daniel D.
Bikle, MD, PhD, a professor of medicine and dermatology at UCSF.

As an NSBRI Fellow, Long will receive $40,000 per year for two years for his
research at SFVAMC. In addition, as a member of an NSBRI science and
technology team, he will collaborate in person and via teleconference with
NSBRI colleagues. He and the other two Fellows were chosen from among a
nationwide pool of applicants.

"The loss of mechanical forces on bone in the weightlessness of space
dramatically weakens bone," says Long. "The ability of humans to conduct
prolonged missions to the Moon and Mars will require that the structural
integrity of the skeleton be maintained."

Astronauts who spend weeks or months in the weightless environment of space
-- a state called skeletal unloading -- lose bone because, in the absence of
gravity, they lose the ability to make enough new bone cells to replace old
cells that die in the normal course of bone metabolism. After their return
to Earth's gravity, an event known as reloading, bone cell production can
take months to return to normal. During that time, bones are highly
vulnerable to fracture.

Here on Earth, explains Bikle, immobilized patients experience bone loss for
the same reason astronauts do: their skeletons have not borne any weight.
"This makes their rehabilitation risky, because, like astronauts who have
returned to earth, they are predisposed to fractures."

Long's research project will focus on the relationship between three
substances: insulin-like growth factor-1 (IGF-1), a chemical produced in
bone and other organs that promotes the growth of bone and cartilage; IGF-1
receptor, which resides in bone cells and enables them to respond to IGF-1;
and beta-3 integrin, a protein that among other roles promotes the function
of IGF-1 receptor.

Long's and Bikle's hypothesis is that during prolonged weightlessness,
beta-3 integrin production decreases, which in turn diminishes the function
of IGF-1 receptor in bone. Without its receptor, IGF-1 has been shown by
researchers to be ineffective. The result is a steep drop in the creation of
new bone cells, leading to bone loss.

To investigate the hypothesis, Long will take a two-pronged research
approach. In the first part, he will study a model of skeletal loading and
unloading in human bone cell culture. In the second part, skeletally
unloaded rats will be treated with IGF-1 and reloaded on a regular cycle --
much as astronauts might regularly engage in weight-bearing exercise while
in orbit -- in order to stimulate integrin production and enhance or recover
IGF-1 receptor function. The IGF-1 will act as a signaling device to allow
Long to measure the strength of the interaction between integrins and IGF-1
receptor.

"Understanding this interaction, and the role it plays in how bones respond
to mechanical forces, will allow interventions to protect the bones of
astronauts," Long says.

"We hope to find that we can manipulate the IGF-1 system to accelerate
rehabilitation, not only among astronauts but among a broad range of
patients," says Bikle. "We might also learn how to prevent bone loss from
taking place."

Long concludes, "I am excited and honored to contribute to our nation's
efforts to safely explore space, the Moon, and Mars."

NSBRI, which is funded by NASA, studies the health risks related to
long-duration space flight.

SFVAMC has the largest medical research program in the national VA system,
with more than 200 research scientists, all of whom are faculty members at
UCSF.

UCSF is a leading university that advances health worldwide by conducting
advanced biomedical research, educating graduate students in the life
sciences and health professions, and providing complex patient care.

Web links to additional information:

* University of California San Francisco
http://www.ucsf.edu
* Northern California Institute for Research and Education
http://www.ncire.org