We know that demyelination is central to the pathology of the injury, and its reversal by means of injecting oligodendrocyte
progenitor cells would be revolutionary for the field.
Among the experimental treatments being tested now for multiple sclerosis are transplanting myelin-producing oligodendrocytes
into animals' brains and using drugs that "fiddle with' electrical impulses in the brain so messages can be transmitted without myelin, according to Byron Waksman of the New York-based National Multiple Sclerosis Society.
In contrast, there was no cavity in the spinal cord of the rodents that had been injected with hESC-derived OPCs seven days after injury, and the transplant area contained human oligodendrocytes
The finding, which they demonstrated in rats and cultured rat brain cells, suggests a key role for oligodendrocytes
in long-term and perhaps permanent changes in the brain that could set the stage for later mental problems.
progenitor cells derived from human embryonic stem cells express neurotrophic factors.
They showed in lab dishes that fingolimod could regulate many aspects of oligodendrocyte
function or behavior, such as cell survival, differentiation, and extension toward nerve fibers.
progenitor cells are grown in the laboratory from stem cells obtained from early-stage discarded human embryos.
TNF presence correlates inversely with mature oligodendrocyte
survival, (1,2) a finding consistent with a direct toxic effect of TNF for oligodendrocytes
as has been shown in vitro (3) and in vivo.
Scientists from Canada and elsewhere in the world detail such procedures as the neural differentiation of human embryonic stem cells, primary sensory and motor neuron cultures, oligodendrocyte
progenitor cell culture, cerebellar slice cultures, live imaging of neural cell functions, and tissue culture procedures and tips.
The company will recruit eight to 10 recently injured patients and inject them with small numbers of human embryonic stem cells manipulated to become the oligodendrocyte
cells that insulate nerves, and that produce compounds to stimulate the growth of nerve cells.
We have already shown that human oligodendrocyte
precursors will mature and form new myelin very effectively when transplanted into the brains of mice," said team member Dr.
They also review how different cells (T and B cells, macrophages, microglia) and the complement system promote demyelination of and injury to axons, which leads to oligodendrocyte
Even though the oligodendrocytes
are damaged, there is a reservoir of oligodendrocyte
precursor cells (OPCs), left over from development that could be activated to repair the damage, he said.
Other postmortem studies have shown significantly diminished oligodendrocyte
counts and abnormal distribution of these cells in older patients, he said.
In culture, oligodendrocyte
precursor cells, which normally give rise to just oligodendrocytes
, can be converted to multipotent stem cells that will differentiate into all three neural cell types-neurons, astrocytes, and oligodendrocytes