| For the first time, scientists have
successfully transformed unspecialized embryo cells into bone, according to a presentation
by British researchers at a symposium for stem cell research in London. Approximately 90%
of the stem cells from a mouse embryo grew into bone within 21 days. The researchers hope
to produce the same results with human embryos, which may eventually lead to improvements
in treating patients with severe bone injuries or diseases, such as osteoporosis. In the study, Lee Buttery of the Imperial College School of Medicine in London
and his colleagues removed stem cells from a mouse embryo and grew the cells in their
laboratory. Unspecialized stem cells develop a few days after an embryo is created and
give rise to all of the body’s cells. Some stem cells are also present in adults, but
researchers say these cells are not as flexible as unspecialized cells found in embryos.
To help the stem cells grow, Buttery
and his colleagues added a few components to the cell samples, including steroid hormones
and bits of fetal bone that released bone growth factors. After 21 days, 90% of the cells
transformed into bone nodules. The researchers also noted that some of the cells
transformed into nerve and muscle cells.
The researchers believe that the same
principles involved in growing stem cells from a mouse embryo could be applied to human
embryos and may lead to major advancements in treating osteoporosis and bone injuries.
According to Buttery, creating purified bone cells to be used in bone repair without the
problems of tissue rejection could also spur significant improvements in bone grafting and
bone prosthesis in patients with traumatic bone injuries.
However, stem cell research is a very
controversial subject, especially when it involves using cells from human embryos.
Recently, the U.S. National Institutes of Health decided to allow federally funded
research using stem cells from human embryos. Many of those who oppose embryo research say
that researchers should focus more on how adult stem cells could be used to help create
different cell types. According to Brigid Hogan, a stem cell researcher from Vanderbilt
University, researchers have also shown that skin taken from adults could be turned into
bone.
Stem cell research also offers
promising medical advances in treating other diseases. The most exciting prospects include
making transplantable brain cells for patients with Parkinson’s disease and
pancreatic cells that produce insulin for patients with diabetes. Researchers are also
investigating whether implanting nerve cells in the region of the brain damaged by stroke
could help restore brain function. In a preliminary study involving 12 stroke patients, 50% of the
patients showed significant improvement 24 weeks after the nerve cells were implanted.
If further research with human embryos
proves successful, the researchers say that growing bone from stem cells could help
improve the lives of patients with severe osteoporosis. Osteoporosis is a degenerative
bone disease that affects mostly post-menopausal women. It is estimated that one in two
women over 50 will have an osteoporosis-related fracture. Literally meaning "porous
bone," osteoporosis is characterized by a decrease in normal bone density due to the
loss of calcium and collagen. A loss of bone density causes bones to become brittle, and
in turn, leads to frequent fractures and other serious effects. Osteoporosis is a threat
to 28 million Americans and is currently one of the most under-diagnosed and under-treated
disorders in medicine.
Current methods of preventing and
treating osteoporosis include maintaining a diet rich in calcium and vitamin D. Women with
low bone mineral density may also wish to
consider taking hormone replacement therapy or other
drug therapies, such as raloxifene
(brand name, Evista), alendronate
(brand name, Fosamax), calcitonin
(brand name, Miacalcin), and risedronate
sodium (brand name, Actonel).
Additional Resources and References
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