Email this page
Print this page
del.icio.us
digg
Comments
Mice have minuscule bones. (Canadian author Farley Mowat, in researching the diet of Arctic wolves for his book Never Cry Wolf, ate mice whole, bones and all.) But thanks to new magnetic image resonating technology, Jackson Laboratory researchers are using data from studies of minuscule mouse bones to help pinpoint genetic indicators of osteoporosis in humans.
"These are tiny, tiny animals," says Clifford Rosen, MD, a Bangor physician and senior staff scientist at the Jackson Laboratory in Bar Harbor. He picks up a metallic mouse from behind his desk at his Bangor office and turns it over in his hand. "Now we can actually see inside their bones."
Rosen is part of a one-of-a-kind study being conducted at Jax, where he is a senior staff scientist. "It's very original stuff. I'm very excited about it," says Rosen, who travels to Jackson Lab two days a week to conduct research. "It's the mice that can tell us how the genes regulate bone density."
Osteoporosis (meaning, literally, porous bones) is a disease that makes bones prone to fracture. It affects more than 10 million Americans, most of them postmenopausal women.
In addition to ongoing work at Jackson Lab, many clinical trials for osteoporosis treatments are taking place at the Maine Center for Osteoporosis Research and Education at St. Joseph Hospital in Bangor. In 2006, in fact, findings about a clinical trial, conducted in part at the center, were published in the New England Journal of Medicine. Local participants helped researchers discover that two common osteoporosis medications, when used sequentially, were nearly 30% more effective.
While clinical trials are useful in helping with treatment, the most cost-effective solution would be to discover ways to prevent the disease in the first place.
Dr. Rosen points out an example of osteoporosis on the wall of his office. It's a signed print from the children's book Miss Rumphius, by the late Maine author/illustrator Barbara Cooney. The book's title character, as she ages, exhibits the stages of bone loss, until she is stooped and fragile. Scientists' goal is to help the Miss Rumphiuses of the world keep strong bones throughout their lives. To do this, the Jax study is looking not just at the mice's bone cells, but also at their fat cells.
The search for fat cells is crucial, Rosen says, because it can tell researchers how effectively bone cells are being replaced as the mouse ages. Both bone cells and fat cells begin their lives in the body as stem cells in the bone marrow. At some point, researchers believe, a genetic "switch" in the cell tells it to become either a bone-forming cell or a fat cell. The aim of the Jackson Lab study is to identify the genes that make that decision.
So far, the researchers have found that when a certain chemical in the stem cell is stimulated, that cell is more likely to turn into a fat cell. A preponderance of fat cells weakens the bone. "If we can identify the genes that affect bone density in mice, we can then go to humans and say, 'You are at risk,' and possibly preempt the presentation of the disease," through exercise, diet, supplements, and other preventive treatments.
Another new local clinical trial may soon help solidify a link between diabetes and bone loss. Preliminary research has shown that certain medications that stimulate the production of insulin may also accelerate the production of fat cells. The Maine Center for Osteoporosis Research and Education has applied to the National Institutes of Health for funding of an impartial study of a powerful new diabetes drug called Rosiglitazone, in which 150 women in Bangor and San Francisco will participate. These non-diabetic but insulin-resistant women will be given the drug or a placebo, and be monitored for insulin and blood-sugar levels, as well as for bone density and the percentage of fat cells in their bones.
Such clinical trials can pave the way for effective new treatments, Rosen says. But drug companies, with vested interests in the outcomes, are often reluctant to fund tests that might produce results unfavorable to their products. The NIH-funded tests will be objective, and the trials thoroughly vetted by the institutional review board at St. Joseph Hospital, where the center is located. Volunteers taking part in clinical trials receive medications and care at no cost.
It's a long way from the options osteoporosis patients had back when Rosen started his career as an MD.
"When I did general medicine in the 1970s," he reflects, "I took care of a lot of osteoporosis patients. We had nothing for them back then. All of a sudden it's become clear that we, as a sophisticated medical community, can do clinical research."
And such research, whether it involves humans or mice, will ultimately keep millions of us staying stronger and standing taller till the end of our days.
"These are tiny, tiny animals," says Clifford Rosen, MD, a Bangor physician and senior staff scientist at the Jackson Laboratory in Bar Harbor. He picks up a metallic mouse from behind his desk at his Bangor office and turns it over in his hand. "Now we can actually see inside their bones."
Rosen is part of a one-of-a-kind study being conducted at Jax, where he is a senior staff scientist. "It's very original stuff. I'm very excited about it," says Rosen, who travels to Jackson Lab two days a week to conduct research. "It's the mice that can tell us how the genes regulate bone density
Advertisement
Osteoporosis (meaning, literally, porous bones) is a disease that makes bones prone to fracture. It affects more than 10 million Americans, most of them postmenopausal women.
In addition to ongoing work at Jackson Lab, many clinical trials for osteoporosis treatments are taking place at the Maine Center for Osteoporosis Research and Education at St. Joseph Hospital in Bangor. In 2006, in fact, findings about a clinical trial, conducted in part at the center, were published in the New England Journal of Medicine. Local participants helped researchers discover that two common osteoporosis medications, when used sequentially, were nearly 30% more effective.
While clinical trials are useful in helping with treatment, the most cost-effective solution would be to discover ways to prevent the disease in the first place.
Dr. Rosen points out an example of osteoporosis on the wall of his office. It's a signed print from the children's book Miss Rumphius, by the late Maine author/illustrator Barbara Cooney. The book's title character, as she ages, exhibits the stages of bone loss, until she is stooped and fragile. Scientists' goal is to help the Miss Rumphiuses of the world keep strong bones throughout their lives. To do this, the Jax study is looking not just at the mice's bone cells, but also at their fat cells.
The search for fat cells is crucial, Rosen says, because it can tell researchers how effectively bone cells are being replaced as the mouse ages. Both bone cells and fat cells begin their lives in the body as stem cells in the bone marrow. At some point, researchers believe, a genetic "switch" in the cell tells it to become either a bone-forming cell or a fat cell. The aim of the Jackson Lab study is to identify the genes that make that decision.
So far, the researchers have found that when a certain chemical in the stem cell is stimulated, that cell is more likely to turn into a fat cell. A preponderance of fat cells weakens the bone. "If we can identify the genes that affect bone density in mice, we can then go to humans and say, 'You are at risk,' and possibly preempt the presentation of the disease," through exercise, diet, supplements, and other preventive treatments.
Another new local clinical trial may soon help solidify a link between diabetes and bone loss. Preliminary research has shown that certain medications that stimulate the production of insulin may also accelerate the production of fat cells. The Maine Center for Osteoporosis Research and Education has applied to the National Institutes of Health for funding of an impartial study of a powerful new diabetes drug called Rosiglitazone, in which 150 women in Bangor and San Francisco will participate. These non-diabetic but insulin-resistant women will be given the drug or a placebo, and be monitored for insulin and blood-sugar levels, as well as for bone density and the percentage of fat cells in their bones.
Such clinical trials can pave the way for effective new treatments, Rosen says. But drug companies, with vested interests in the outcomes, are often reluctant to fund tests that might produce results unfavorable to their products. The NIH-funded tests will be objective, and the trials thoroughly vetted by the institutional review board at St. Joseph Hospital, where the center is located. Volunteers taking part in clinical trials receive medications and care at no cost.
It's a long way from the options osteoporosis patients had back when Rosen started his career as an MD.
"When I did general medicine in the 1970s," he reflects, "I took care of a lot of osteoporosis patients. We had nothing for them back then. All of a sudden it's become clear that we, as a sophisticated medical community, can do clinical research."
And such research, whether it involves humans or mice, will ultimately keep millions of us staying stronger and standing taller till the end of our days.
