A new study shows that when specific human brain cells are transplanted into animal models of multiple sclerosis and other white matter diseases, the cells repair damage and restore function. The study provides one of the final pieces of scientific evidence necessary to advance this treatment strategy to clinical trials.

The findings are the culmination of more than 15 years of research at University of Rochester Medical Center understanding support cells found in the brain called glia, how the cells develop and function, and their role in neurological disorders.

The researchers have developed techniques to manipulate the chemical signaling of embryonic and induced pluripotent stem cells to create glia. A subtype of these, called glial progenitor cells, gives rise to the brain's main support cells, astrocytes and oligodendrocytes, which play important roles in the health and signaling function of nerve cells.

In MS, glial cells are lost during the course of the disease. Specifically, the immune system attacks oligodendrocytes. These cells make a substance called myelin, which, in turn, produce the "insulation" that allow neighboring nerve cells to communicate with one another.

As myelin is lost during disease, signals between nerve cells becomes disrupted, which results in the loss of function reflected in the sensory, motor, and cognitive deficits. In the early stages of the disease, referred to as relapsing multiple sclerosis, the lost myelin is replenished by oligodendrocytes. However, over time these cells become exhausted, can no longer serve this function, and the disease becomes progressive and irreversible.

In the new study, researchers showed when human glia progenitor cells are transplanted into adult mouse models of progressive MS, the cells migrated to where they were needed in the brain, created new oligodendrocytes, and replaced the lost myelin. The study also showed that this process of remyelination restored motor function in the mice.

Results of mouse model studies sometimes do not translate to humans and may be years away from being a marketable treatment. However, this research is in the process of being developed by a University of Rochester start-up company Oscine Therapeutics. The company's experimental transplant therapy for MS is currently under early FDA review for clinical trials.

The findings were published in the journal Cell Reports.