Stem Cells Found in Human Parasite, Schistosoma mansoni Renews Tissue (VIDEO)

Most wouldn't consider there to be anything special about a parasitic flatworm. In particular, for the Schistosoma mansoni, you might even consider this little thing flat out disgusting. If you want to get a little grosser, this thing actually hatches in feces-tainted water, grows into a larva in the body of a snail and then burrows through human skin to take up residence in the veins. And, once there, it grows into an adult, mates, and if it's female, starts laying eggs, and can even remain in the body for decades.

However, University of Illinois cell and developmental biology professor Phillip Newmark and postdoctoral researcher Jim Collins and their colleagues have discovered that this disgusting bug renews its tissues with the help of stem cells.

A new study researchers pieced together offers insight into the cellular operations that give this flatworm some extraordinary staying power. They have demonstrated that the S. mansoniharbors adult, non-sexual stem cells that can migrate to various parts of its body and replenish tissues, which appears in the journal Nature.

According to the World Health Organization, more than 230 million people are in need of treatment for Schistosoma infections every year. Most live in impoverished areas with little or no access to clean water. Infection with the worm (also known as a blood fluke) can lead to damaging inflammation spurred by the presence of the worm's eggs in human organs and tissues.

Children in particular are especially vulnerable to the effects of infections. In some cases, they may even experience delays in growth and brain development as a result of the chronic inflammation.

"It just stood to reason that since schistosomes, like planaria, live so long that they must have a comparable type of system," Collins said.

In a series of experiments, Collins found that the schistosomes were loaded with proliferating cells that looked and behaved like planarian neoblasts, the cells that give them their amazing powers of regeneration. Like neoblasts, the undifferentiated cells in the schistosomes lived in the mesenchyme, a kind of loose connective tissue that surrounds the organs. And like neoblasts, these cells duplicated their DNA and divided to form two "daughter" cells, one of which copied its DNA again, a process that normally precedes cell division.

Researchers note that this provides some interesting insight into the life-cycle of the flatworm that might be applied to other biological aspects. It's cetainly disgusting, but we have to agree, regenerating cells can only be a positive thing. 

Want to learn more about the flatworm? Check out this video, courtesy of YouTube.