Amniotic fluid yields alternatives to embryonic stem cells

Stem cells found in amniotic fluid can be transformed into a more versatile state similar to embryonic stem cells, according to a study by scientists from Imperial College London and the UCL Institute of Child Health who succeeded in reprogramming amniotic fluid cells without having to introduce extra genes.

Amniotic fluid cells grown on a gelatinous protein mixture in the lab were reprogrammed into a more primitive state by adding a drug called valproic acid to the culture medium. Even after growing in culture for some time, the reprogrammed cells were able to develop into functioning cells of many different types, including liver, bone and nerve cells. They also maintained their pluripotency even after being frozen and rethawed.

Dr Pascale Guillot, from the Department of Surgery and Cancer at Imperial, said: "Amniotic fluid stem cells are intermediate between embryonic stem cells and adult stem cells. They have some potential to develop into different cell types but they are not pluripotent. We've shown that they can revert to being pluripotent just by adding a chemical reagent that modifies the configuration of the DNA so that genes that are expressed in the embryo get switched back on.

"These cells have a wide range of potential applications in treatments and in research. We are particularly interested in exploring their use in genetic diseases diagnosed early in life or other diseases such as cerebral palsy."

Dr Paolo De Coppi, from the UCL Institute of Child Health, who jointly led the study with Dr Guillot, said: "This study confirms that amniotic fluid is a good source of stem cells. The advantages of generating pluripotent cells without any genetic manipulation make them more likely to be used for therapy.

"At GOSH we have focused on building organs and tissues for the repair of congenital malformations, which are usually diagnosed during pregnancy. Finding the way of generating pluripotent cells from the fluid that surround the fetus in the womb move us one step further in the this direction".

The study was funded by the Genesis Research Trust, the Henry Smith Charity and Action Medical Research.

Findings have been published in the Molecular Therapy