July 28, 2009

Possible embryonic stem cell option

Sperm cell precursors can be converted into other cell types, providing a possible alternative to the medical use of embryonic stem cells, U.S. researchers say.

The University of Illinois research, described in the journal Stem Cells, improves on earlier research that showed that a kind of germ cell that leads to the production of sperm could eventually give rise to a few cells that looked and acted like embryonic stem cells.

But the earlier process with the spermatagonial stem cells took months, and only a small portion of the cells evolved into embryonic stemlike cells, veterinary biosciences Professor Paul Cooke and postdoctoral researcher Liz Simon said.

In their new research, Simon placed spermatagonial stem cells from inbred mice on the connective tissue in embryos and grafted the combination into living mice.

They found that the spermatagonial stem cells, under the right conditions, formed new tissues that had all the physical characteristics of prostate, skin or uterus and produced the telltale markers of those tissue types, they said.

The original cells stopped looking and behaving like spermatagonial stem cells, Cooke said.

Cooke said he hopes a more streamlined approach can be developed to produce new skin cells or other tissues when needed -- for example, to replace skin damaged in a burn.

His team is also investigating the use of ovarian stem cells instead of spermatagonial stem cells to see if they can get the same results with ovarian tissue.