Apr 16, 2003
By Rossella Lorenzi
Adult neural precursor cells injected intracerebrally or intravenously migrate to demyelinated sites, differentiate into myelin-producing cells, and restore clinical function in a mouse model of multiple sclerosis, Italian researchers reported on Wednesday.
The San Raffaele Scientific Institute researchers also report their findings in the 17 April issue of Nature.
Dr. Gianvito Martino, Dr. Angelo L. Vescovi and others cultured neural stem cells from the periventricular region of the forebrain ventricles of adult C57BL/6 mice. Ten days after the injection into mic with experimental autoimmune encephalomyelitis, the syngenic adult neural stem cells reached the damaged areas; within 30 days they entered the damaged area, and then proceeded to differentiate into the myelin-producing oligodendrocytes.
"Thirty percent of mice recovered, seventy percent improved significantly," Dr. Martino said at a press conference on Wednesday.
"The novelty of this study is the possibility to induce myelin repair in multiple areas of the brain and spinal cord by transplanting brain stem cells not only directly within the central nervous system, but also into the circulation," he noted.
"We realized that the donated cells have a key to pass through the blood brain barrier and enter into the central nervous system. This was the first step to other amazing discoveries," Dr. Martino told Reuters Health.
Indeed, more than 90% of the cells expressed the adhesion protein CD44 and very late antigen VLA-4, indicating a potential to interact with the blood-brain barrier, the researchers report.
"Our results show that the mechanism is bimodal," Dr. Martino elaborated in comments to Reuters Health. "The efficacy of brain stem transplantation in mice not only focuses on their ability to repair damaged areas. Transplanted cells are also able to foster endogenous myelin-producing cells to repair the lesions."
The researchers stressed that the work is at a early stage. Within two months, Drs. Martino and Vescovi plan to begin non-human primate studies, while potential therapeutic applications in humans might take from 5 to 10 years.
© 2003 Reuters Ltd