Stem cells may be present in the amniotic fluid that cushions a baby in its mother鈥檚 womb, suggests a new study.
If these cells prove to have the power to differentiate into different tissue types, they may provide a solution to the ethical dilemma associated with using human embryonic stem cells (ESCs), say reproductive scientists.
Markus Henstschl盲ger and colleagues at the University of Vienna, Austria, found that some cells in the amniotic fluid taken from pregnant women during routine amniocentesis expressed a key protein called Oct-4. This is needed to keep ESCs in their state of perpetual youth. Further investigation showed that other important proteins were also expressed.
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ESCs are 鈥減luripotent'鈥�, i.e. they are primitive cells capable of differentiating into all the different cell types in the body. Many scientists believe they hold great potential for the treatment of degenerative diseases, such as Parkinson鈥檚 disease. But ESCs are most easily obtained by destroying embryos, a practice some find ethically unacceptable.
Henstschl盲ger鈥檚 team say their work shows human amniotic fluid 鈥渕ay represent a new source for stem cells without raising the ethical concerns associated with human embryonic research鈥�.
Arne Sunde, new chairman of the European Society of Human Reproduction and Embryology, highlighted the findings at the society鈥檚 annual conference in Madrid on Monday, amid concerns that proposed legislation by the European Union might halt stem cell research.
Stormy ride
鈥淚n countries where the use of ESCs could be banned, maybe the use of amniotic fluid stem cells will be acceptable.鈥� Sunde told 快猫短视频. But he cautioned that more research was needed to show the idea was practical.
The controversy over ESC research has meant a stormy ride for an EU-wide directive setting standards for tissue donation, testing and distribution. The proposed directive was amended to include a ban on research designed to create human embryos solely for research purposes or to supply stem cells.
This was overturned on 2 June, leaving the choice over such a ban to individual EU member countries. 鈥淗owever, there will almost certainly be moves to reinstate the ban at the second reading in parliament,鈥� stresses a statement from ESHRE.
Sunde opposes the ban and says research on stem cells from embryos remains crucial, but adds that Henstschl盲ger鈥檚 study highlights that non-embryo based stem cell research is progressing.
Rare but detectable
The Austrian team tested samples of amniotic fluid from 11 women in week 14 of pregnancy and found genetic material coding for Oct-4 in five samples. Cells expressing factors associated with Oct-4 were rare, but detectable, being found in no more than one in 200 cells.
Hengstschlager says it will take two years to find out what the cells are capable of turning into, although preliminary experiments suggest they can become nerve cells.
Sunde says that the clinical implications of stem cells from amniotic fluid are difficult to draw without knowing their potential and speed at which they might differentiate. 鈥淲ould they have a high enough growth potential?鈥� he asks. 鈥淭hey must be able to multiply fast enough.鈥�
He adds they may also be useful as a resource for the newborn baby itself. In some countries, parents are already freezing blood from the umbilical cord of newborns, because this preserves stem cells as a 鈥渂ack-up鈥� for the future.
Journal reference: Human Reproduction (vol 18, p 1489)