The prospect of doing human clinical trials with stem cells to treat diseases like multiple sclerosis
may be growing closer, say scientists at the University at Buffalo and
the University at Rochester, who have developed a more precise way to
isolate stem cells that will make myelin.
Myelin is the crucial fatty material that coats neurons and allows them
to signal effectively. The inability to make myelin properly is the
cause of MS as well as rare, fatal, childhood diseases, such as Krabbe's
disease.
The research, published online and in the October issue of Nature
Biotechnology, overcomes an important barrier to the use of stem cells
from the brain in treating demyelinating diseases.
Until now, it has been difficult to separate out the right progenitor
cells the ones that will develop into cells that make myelin, explains
Fraser Sim, PhD, first and co-corresponding author on the paper and
assistant professor in the Department of Pharmacology and Toxicology in
the UB School of Medicine and Biomedical Sciences; he did much of the
work while he was a researcher at Rochester.
"Characterizing and isolating the exact cells to use in stem cell
therapy is one key to ultimately having success," said Sim. "You need to
have the right cells in hand before you can even think about getting to
a clinical trial to treat people. This is a significant step."
Sim and Rochester graduate student Crystal McClain ran extensive
analyses looking at gene activity in different types of stem cells,
leading to the conclusion that stem cells carrying a protein known as
CD140a on their surface seemed to be most likely to become
oligodendrocytes the type of brain cell that makes myelin.
The UB and Rochester scientists then injected the cells into the brains
of mice that were born without the ability to make myelin. Twelve weeks
later, the cells had become oligodendrocytes and had coated more than 40
percent of the brain's neurons with myelin a four-fold improvement over
the team's previous results published in Cell Stem Cell and Nature
Medicine.
"These cells are our best candidates right now for someday helping
patients with M.S., or children with fatal hereditary myelin disorders,"
said Steven Goldman, MD, PhD, co-author, the leader of the team and
professor and chair of the Department of Neurology at the University of
Rochester Medical Center. "These cells migrate more effectively
throughout the brain, and they myelinate other cells more quickly and
more efficiently than any other cells assessed thus far. Now we finally
have a cell type that we think is safe and effective enough to propose
for clinical trials."
An eventual treatment of a disease like M.S. might involve injecting stem cells to create myelin in the brains of patients.
"Another approach," says Sim, "might involve using certain medications
to turn on these cells already present in the brains of patients and
thereby create new myelin. The use of the new techniques described in
this work will permit us to better understand how human cells behave in
the brain and help us predict which medications may be successful in the
treatment of myelin loss."
The new approach may also be applicable to Krabbe's Disease, Sim says,
which also involves the breakdown of myelin. Sim, who came to UB in
2009, is actively collaborating on related work with researchers at the
Hunter James Kelly Research Institute, a partnership between UB and the
Hunter's Hope Foundation and located in UB's New York State Center of
Excellence in Bioinformatics and Life Sciences.
Friday, October 14, 2011
New Method Isolates Best Brain Stem Cells To Treat MS
6:28 PM