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    Alessandra d'Azzo, PhD

    Alessandra d'Azzo, PhD



    Genetically modified cells treat nerve degeneration

    Physicians might one day be able to treat a disease that destroys brain cells in children using genetically modified cells to transport a “drug” to the site of the dying neural cells (cells that transmit impulses). The discovery occurred based on results of a laboratory study of the technique published by St. Jude investigators. A report on this work appears in the prepublication online issue of Blood.

    There is currently no cure for such disorders, which are called lysosomal storage diseases (LSDs).

    The St. Jude researchers successfully treated a laboratory model of an LSD called GM1 – gangliosidosis using bone marrow cells (BMCs) into which scientists inserted the gene for an enzyme that breaks down a fat molecule called GM1. GM1 is a critical component of normal brain cells. But in GM1 – gangliosidosis, brain cells lack this enzyme—beta-galactosidase—and GM1 accumulates to such a high concentration that it disrupts the proper function of the cell and causes it to self-destruct. BMCs include a population of so-called pluripotent stem cells—cells that give rise to a variety of different cell types that have specific functions, such as the immune cells called monocytes.

    After the St. Jude team infused the genetically modified BMCs into the laboratory model, resulting monocytes migrated to the degenerating brain cells that lacked the gene for beta-galactosidase. These cells took in the enzyme released by the monocytes and used it to break down excess GM1, thus correcting the potentially fatal buildup of this molecule.

    The monocytes homed in on the brain by following a trail of signaling molecules that were released by cells adjacent to the degenerating neurons, according to Alessandra d’Azzo, PhD, of Genetics and Tumor Cell Biology. d’Azzo is senior author of the article in Blood. “We used the brain’s own signaling molecules to guide the genetically modified monocytes,” d’Azzo said.

    “We showed that improvement of the disease was directly related to the amount of genetically modified monocytes reaching the degenerating brain cells,” said researcher Renata Sano, PhD, of Genetics and Tumor Cell Biology and the paper’s first author. “Overall, our findings suggest that if this technique could be adapted to treat children with this type of LSD we would have an effective therapy.”

    The other authors of this paper include Angela Ingrassia of Genetics and Tumor Cell Biology and Alessandra Tessitore of the Telethon Institute of Genetics and Medicine in Naples, Italy.

     

    Last update: July 2005