Stem Cells Found in Amniotic Fluid
Amniotic Fluid Stem Cells Can Become Brain, Bone, Liver Cells, and More
Jan. 9, 2007 -- Stem cells found in discarded amniotic fluid may hold the
key to new treatments for disease and injury.
The newly discovered amniotic fluid stem cells may not be
"pluripotent," or capable of forming every type of adult tissue. But
they come very close. When grown in the right environment, they can become fat
cells, bone cells, brain cells, muscle cells, blood vessel cells, or liver
And when transplanted into special mice, human amniotic fluid stem cells
placed in the brain become functional brain cells. After being placed on
scaffolds and properly nourished in the test tube, stem cells implanted into
mice form bone.
The findings come from the lab of Anthony Atala, MD, director of the
Institute for Regenerative Medicine at Wake Forest University in Winston-Salem,
"Amniotic fluid stem cells hold potential for a variety of therapeutic
applications," Atala and colleagues suggest.
The amniotic fluid stem cells may, in fact, have an advantage over embryonic
stem cells. The embryonic cells have a tendency to grow wildly and form tumors.
The amniotic fluid stem cells do not form tumors.
Another obvious advantage is that the stem cells come from the amniotic
fluid obtained from a previously planned amniocentesis. This fluid would
normally be discarded.
During amniocentesis, doctors take a small amount of amniotic fluid from the
womb by inserting a fine needle into the uterus through the abdomen, under
ultrasound guidance. It is done to check for some types of birth defects, such
as Down syndrome.
Though the stem cells do seem to come from the developing fetus -- cells
from the fluid surrounding male children carry a male Y chromosome -- the cells
are harvested from the amniotic fluid and not from the fetus itself. Similar
cells can be found in the placenta after full-term pregnancies.
The findings appear in the advance online publication of the journal
The new findings, while exciting, do not eliminate the need for embryonic
stem cells, cautions a news release from the Genetics Policy Institute (GPI), a
nonprofit organization that advocates for stem cell research.
"There is only one 'card carrying' pluripotent human embryonic stem
cell," GPI director Bernard Siegel, JD, says in the news release. "Most
scientists believe that different types of stem cells will eventually be needed
to treat different diseases."