The study not only identifies an important targeting mechanism in transplanted stem cells but also provides a blueprint for engineering stem cell-based therapies for multiple sclerosis and other chronic neurological diseases in which inflammation occurs.
The researchers used adult neural stem cells to treat mice with a disease similar to MS that destroys myelin, the protective tissue coating on nerves, causing chronic pain and loss of motor function. Adult neural stem cells have shown the ability to change or differentiate into oligodendrocytes, the building blocks of myelin, and repair or replace affected tissue.
In the mice, inflammatory cells - reacting to the virally induced nerve damage - were observed activating receptors on the adult neural stem cells. These CXCR-4 receptors, in turn, recruited chemokine proteins called CXCL-12 that guided the stem cells to specific sites. Chemokines are produced in acute and chronic inflammation to help mobilize white blood cells.
As the stem cells migrated through the central nervous system, they began to transform into the precursor cells for oligodendrocytes. Latching onto their repair sites, they continued the differentiation process. Three weeks after the initial treatment, 90 percent of the cells had grown into fully formed oligodendrocytes.
“Previously, we’ve seen that adult neural stem cells injected into the spinal column knew, amazingly, exactly where to go,” said Lane, professor of molecular biology and biochemistry. “We wanted to find what directed them to the right injury spots.”
In earlier work, Lane and colleagues demonstrated that adult neural stem cell treatments improved motor function in mice with chronic MS symptoms.
“In this study, we’ve taken an important step by showing the navigational cues in an inflammatory environment like MS that guide stem cells,” said Lane. “Hopefully, these cues can be incorporated into stem cell-based treatments to enhance their ability to repair injury.”
MEDICA.de; Source: University of California