Scientists
from China have developed a method to generate neural progenitor cells from
epithelial-like cells in human urine.
Scientists from China have developed a method
to generate neural progenitor cells from epithelial-like cells in human urine.
Human urine contains kidney epithelial cells
that are naturally shed and therefore constitutes a rich source of
patient-specific cells that is easily obtainable.
A team of scientists at the Guangzhou
Institutes of Biomedicine and Health, led by Prof Pei Duanqing, have developed
a new method to reprogram adult urine kidney epithelial cells into neural
progenitor cells (NPCs). Their protocol combines an episomal system to deliver
reprogramming factors with a chemically defined culture medium.
Reprogramming of adult cells usually takes
several weeks before becoming fully pluripotent, which refers to the ability of
a cell to generate any cell type in the body.
With the new method, reprogrammed cells
preferentially committed to becoming NPCs at an early stage before entering a
fully pluripotent state. The NPCs could proliferate when grown in dishes and
could differentiate into neuronal subtypes and glial cells.
Importantly, the NPCs were shown to be
transgene-free and capable of self-renewal. When transplanted into the brains
of newborn rats, the engrafted human NPCs integrated into the host brain and
formed both neurons and astrocytes.
To induce reprogramming of adult cells,
scientists have typically used viruses to deliver the reprogramming factors.
However, Prof Pei’s team avoided the use of viruses by using an episomal system
instead. This method has the benefit of excluding the possibility of viral
integration of the genes encoding the reprogramming factors, which could pose
the risk of tumor formation after transplant.
Tumor formation by rogue undifferentiated
cells is a major concern when transplanting reprogrammed cells. With this new
method, the scientists did not observe the formation of teratomas, which are
tumors derived from pluripotent cells and that contains tissue from all three
germ layers.
Prof Pei and colleagues hope their new
system, published in Nature Methods, can help the search for new treatments for
neurodegenerative disorders.
“We envision that our protocols can be
further applied to human urine cells isolated from patients with neural
disorders such as Parkinson’s disease, Alzheimer’s disease or other
neurodegenerative diseases.
These patient-specific cells should be useful
for modeling disease and for drug screening,” the authors wrote in the paper.
The article can be found at: Wang L et al. (2012) Generation of
integration-free neural progenitor cells from cells in human urine.
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