Researchers in China have found a way to transform cells excreted in human urine into neural progenitor cells, the precursors of brain cells.
These cells can be used to study neurodegenerative diseases such as Parkinson's, and they may also help researchers produce cells custom-tailored to patients "more quickly and from more patients than current methods" allow, Nature magazine reported.
A paper describing the research was published online Dec. 9 in Nature Methods.
"We combined an episomal system to deliver reprogramming factors with a chemically defined culture medium to reprogram epithelial-like cells from human urine into [neural progenitor cells]," the study's abstract states.
In a laboratory setting, the cells were shown to "self-renew and... differentiate into multiple functional neuronal subtypes and glial cells."
While the study's authors wrote that their method still needs to be tested in living tissue, they say it offers researchers key advantages.
For starters, the method does not use embryonic stem cells. In addition to the ethical issues presented by that method, human embryonic stem cells have been observed to form tumors, a 2009 report notes.
In addition, the method produced so-called "pluripotent" cells in about half the time as previously observed. Pluripotency is the desirable trait that allows stem cells to differentiate into one of many cell types.
Once transplanted from lab culture into rat brains, the cells formed no tumors and were observed to take on the "shape and molecular markers" of neurons within four weeks, according to Nature.
The new study builds on work published by members of the team last year, which showed that skin-like cells from the lining of kidney tubules, extracted from urine, "can be efficiently reprogrammed, via the pluripotent state, into neurons, glia, liver cells and heart muscle cells," according to the Guardian.
Earlier this year, a team from Johns Hopkins University published a method for using adult cord blood cells to make stem cells. While previous attempts had far lower yields, using its method, the team was able to convert 50 percent to 60 percent of blood cells engineered into induced-pluripotent stem cells.
The Johns Hopkins team had successfully demonstrated how to safely transform adult blood cells into heart cells in a study published in 2011.