Stem cells from the amniotic fluid

Reprogrammed cells from amniotic fluid can produce all cell types

Human amniotic fluid cells prior to reprogramming (left) to amniotic fluid iPS cells (second image from left) are externally indistinguishable from embryonic stem cells. Amniotic fluid iPS cells produce OCT4 (green), one of the most important stem cell marker proteins. Starting from this embryonic stem cell stage, the amniotic fluid iPS cells can, among other things, form liver cell-like cells (right). They produce the plasma protein alpha-fetoprotein (red). © MPI for Molecular Genetics
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High hopes rest on stem cells: a variety of diseases could one day be treated with it. So far, they are mainly derived from embryos, which, however, brings with it ethical problems. Max Planck scientists have now succeeded in converting cells from the amniotic fluid into stem cells.

Although these amniotic stem cells are hardly distinguishable from embryonic stem cells, they are "reminiscent" of the original cell type from which they originated, report the researchers of the Max Planck Institute for Molecular Genetics in Berlin in the journal "PLoS One",

Cells with special abilities

The special abilities of the embryonic stem cells can be used today in a variety of already mature cells such as skin and hair cells. For this purpose, these cells are reprogrammed and converted into so-called induced pluripotent stem cells (iPS). These then have the typical stem cell properties again: they can form every cell type of the human body - pluripotency - as well as multiply infinitely. The scientists were able to show that the amniotic fluid iPS cells can form different cell types of the human body.

Stem cells with memory

In addition, they have discovered that induced pluripotent stem cells can remember the source cell type from which they originated. When reprogramming the cells, apparently several genes are additionally turned on or remain active, which control the development of the stem cells. This confirms other, recent research findings, according to which iPS cells from different tissues primarily take the same developmental path that they already followed before reprogramming.

"At the moment, we do not know yet whether this stem cell memory affects possible medical treatments and which type of stem cells are best suited for therapy, " says Katharina Wolfrum from the Max Planck Institute for Molecular Genetics. display

Easier reprogramming

Amniotic fluid cells, according to the researchers, have several advantages over other cell types. On the one hand, amniotic fluid cells are routinely obtained from prenatal examinations in order to detect possible diseases early. Usually, more cells are isolated than are actually needed. On the other hand, the amniotic fluid contains a mixture of different cell types of the unborn child, including stem cell-like cells. Because they are not very old, fewer environmental mutations accumulate, which makes them genetically more stable.

It is possible that such cells from the amniotic fluid may be reprogrammed faster and easier than other cell types. This makes amniotic fluid iPS cells an interesting addition to embryonic stem cells, "explains James Adjaye from the Max Planck Institute in Berlin.

Treat sick newborns with the body's own cells

In addition, amniotic fluid cells could be harvested for cellular reprogramming prior to the birth of a child and prepared for their intended use during pregnancy.

In this way, it could be tested before birth, which medications work in a baby and whether it tolerates them. In addition, sick newborns could be treated with the body's own cells, "says Adjaye.

(MPG, 16.11.2010 - DLO)