These unique expressions of sugar on the cell surface may one day enable stem cell therapy to repair brain injury or disease by helping stem cells navigate the relative "jungle" of the adult brain, says Dr. Robert K. Yu, director of the Institute of Neuroscience and the Institute for Molecular Medicine and Genetics at the Medical College of Georgia.

"These glycoconjugate markers are like specific addresses that characterize the cell at that particular moment. We call them stage-specific embryonic antigens," says Dr. Yu of recognition molecules that assist in the unbelievably rapid assemblage of 100 billion to 200 billion cells into a brain in nine months.

The four compounds two glycolipids, GD3 and O-acetylated GD3, and two glycoproteins, Stage-specific Embryonic Antigen-1 and Human Natural Killer Cell Antigen 1 were known, but their role in helping cells migrate where and when needed was unknown.

The findings of Dr. Yu, Postdoctoral Fellow Makoto Yanagisawa and Dr. Sean Liour, co-director of MCG's Human Stem Cell Bank, are being presented during the biannual International Symposium on Glycoconjugates, Sept. 4-9 in Florence, Italy. Dr. Yu is a meeting organizer and is chairing the session on Regulatory Mechanisms for Glycolipid Expression and Intracellular Trafficking.

"We are all sugar-coated, really," says Dr. Yu, who studies these cell surface molecules that change constantly during development. "There is an abundance of sugar on the cell surface, not only that defines the cell's properties but also help cells recognize each other and stick together," he says, noting how like cells bind to form an organ.

During brain formation, for example, cells are constantly changing their sugar face and their function to meet the immediate biological needs. They travel a sort of neuron int
'"/>

Contact: Toni Baker
tbaker@mcg.edu
706-721-4421
Medical College of Georgia
6-Sep-2005