Scientists Develop Stem Cell Strategy Against Parkinson’s Without Need for Transplant

Researchers have developed a new “cell-free” approach — one derived from stem cells — that may treat Parkinson’s disease while avoiding the immune system risks of other stem cell therapies, according to two studies conducted by researcher Leo Behie, from the University of Calgary, in Canada, and collaborators in Portugal.

The newly developed technique shows promise for novel therapeutic opportunities in the future.

One of the studies, “Modulation of the Mesenchymal Stem Cell Secretome Using Computer-Controlled Bioreactors: Impact on Neuronal Cell Proliferation, Survival and Differentiation,” was published in the journal Scientific Reports. The other, “Impact of the Secretome of Human Mesenchymal Stem Cells on Brain Structure and Animal Behavior in a Rat Model of Parkinson’s Disease,” was published in the journal Stem Cells Translational Medicine.

Parkinson’s disease is characterized by the loss of certain types of neurons in the brain, which negatively affects neuronal communication and makes the body unable to control movement. There is currently no cure for the disease, but several researchers have investigated the potential benefits of stem cell technology.

Stem cells are undifferentiated cells that originate all other cell types in the body, including neurons. Stem cells can be stimulated to become the type of neurons that become affected by Parkinson’s and can potentially be transplanted into the patient’s brain, where they would replace the dying neurons.

But in order to make the person’s immune system accept the transplant, patients must take powerful immunosuppressants that leave their bodies susceptible to other diseases.

Behie and the other two leading authors of the studies, António Salgado and Nuno Sousa, developed a new approach that shows potential as a treatment for Parkinson’s and other diseases affecting the nervous system — but does not require a stem cell transplant.

The scientists used computer-controlled bioreactors to arrive at a therapeutic mixture drawn from human stem cells called mesenchymal stem cells, which are found in bone marrow. The mixture, a cultured version of the cells’ secretome, was then injected into the brains of a rat model of Parkinson’s, specifically into the striatum and substantia nigra midbrain area, and seen to aid motor recovery in the rats. (The first study described the process by which the secretome mixture was arrived at and cultured; the second details the animal experiment.)

“We observed that the secretome potentiated the increase of dopaminergic neurons (i.e., tyrosine hydroxylase-positive cells) and neuronal terminals in the SNc [substantia nigra] and STR [striatum], respectively, thereby supporting the recovery observed in the Parkinsonian rats’ motor performance outcomes (assessed by rotarod and staircase tests),” the researchers wrote in the Stem Cells article.

“When the secretome is introduced into the [Parkinson’s] brain, there is a powerful result,” Behie said in a news release. “We were able to show that the injured brains regenerated new neurons.”

Together, the results raise the possibility of a stem cell-based but cell-free treatment for Parkinson’s, with no need for transplants or to suppress the immune system.

The research team is now working with neurosurgeons to bring the therapy into the clinic, Behie said.