Friday, March 14, 2003
United Press International
The adult human brain itself might be a source of neural stem cells that could be used to treat a number of diseases and injuries affecting brain function, new research reveals.
The findings, if verified, could be essential in developing new cell-based therapies for neurological diseases where neurons are lost, such as Alzheimer's, Parkinson's and Huntington's, or where neurons are damaged, such as stroke, epilepsy and traumatic brain injury. In addition, the cells might be used to restore damaged or destroyed brain tissues, thereby eliminating the need for transplants.
The researchers, led by Dr. Steve Goldman, a professor of neurology at Weill Cornell Medical College, discovered that brain cells called glial progenitor cells are capable of developing into neurons, or brain nerve cells.
The cells can be grown and expanded in culture, where they will produce new neurons and glia together, the researchers said. So the glial cells can be considered multipotential progenitor cells -- a form of brain stem cells.
The progentior cells comprise up to 3 percent of cells in the adult human brain's white matter, "making them incredibly abundant," the researchers said.
When Goldman and his colleague, Dr. Neeta Roy, assistant professor of neuroscience, first isolated glial progenitor cells from adult brain white matter about three years ago, they also noticed occasional neurons in the cell cultures. This led them to ask whether the glial cells were generating neurons.
As reported in the latest issue of the British journal Nature Medicine, the glial progenitor cells indeed were found to produce neurons, meaning the cells were functioning as brain stem cells.
The research also determined glial progenitor cells did not need to be reprogrammed to produce neurons -- the cells produced neurons directly. When the researchers introduced adult human glial progenitor cells into the brain of a developing rat, the cells developed into different types of neurons and glia, depending on when and where they were introduced.
Despite the promising results, the researchers said differences remain between adult neural stem cells and fetal stem cells.
For example, the adult cells cannot reproduce indefinitely, unlike their fetal counterparts. Also, investigators have not yet determined whether all white matter glial progenitor cells can act as stem cells, or whether this ability is restricted to a select group within the overall population.
It also is possible malfunctioning glial progenitor cells are linked to some types of brain cancer, they said.
"These considerations aside," Goldman said, "progenitor cells that are
multipotential and capable of forming neurons are abundant in the white
matter of the adult human brain. These cells may prove to have an important
role in the induction and implantation strategies of new cell-based neurological
© Copyright 2003 by United Press International