Parkinson's, which affect as many 10 million people in the
world, is caused by a depletion of dopamine-producing neurons in the brain.
Current treatments include medications and electrical implants in the brain
which causes severe adverse effects over time and fail to prevent disease
progression. Several studies have indicated that the transplantation of
embryonic stem cells improves motor functions in animal models. However, until
now, the procedure has shown to be unsafe, because of the risk of tumors upon
transplantation.
To address this issue, the researchers tested for the first time
to pre-treat undifferentiated mouse embryonic stem cells with mitomycin C, a
drug already prescribed to treat cancer. The substance blocks the DNA
replication and prevents the cells to multiply out of control.
The researchers used mice
modeled for Parkinson's. The animals were separated in three groups. The first
one, the control group, did not receive the stem cell implant. The second one,
received the implant of stem cells which were not treated with mitomycin C and
the third one received the mitomycin C treated cells.
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Figure: Parkinson’s Disease
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After the injection of 50,000 untreated stem cells, the animals
of the second group showed improvement in motor functions but all of them died
between 3 and 7 weeks later. These animals also developed intracerebral tumors.
In contrast, animals receiving the treated stem cells showed improvement of
Parkinson's symptoms and survived until the end of the observation period of 12
weeks post-transplant with no tumors detected. Four of these mice were
monitored for as long as 15 months with no signs of pathology.
Furthermore, the scientists have also shown that treating the
stem cells with mitomycin C induced a four-fold increase in the release of
dopamine after in vitro differentiation.
"This simple strategy of shortly exposing pluripotent stem
cells to an anti-cancer drug turned the transplant safer, by eliminating the
risk of tumor formation," says the leader of the study Stevens Rehen,
Professor at UFRJ and researcher at IDOR.
The discovery, reported on April in the journal Frontiers
in Cellular Neuroscience, could pave the way for researchers and physicians
to propose a clinical trial using pluripotent stem cells treated with mitomycin
C prior to transplant to treat Parkinson's patients and also other
neurodegenerative conditions.
Posted By :-
Bioinformatics Department
BII Noida
