'Support' cells in brain play important role in Down syndrome

PUBLIC RELEASE DATE:

18-Jul-2014

Contact: Charles Casey charles.casey@ucdmc.ucdavis.edu 916-734-9048 University of California - Davis Health System

(SACRAMENTO, Calif.) Researchers from UC Davis School of Medicine and Shriners Hospitals for Children Northern California have identified a group of cells in the brain that they say plays an important role in the abnormal neuron development in Down syndrome. After developing a new model for studying the syndrome using patient-derived stem cells, the scientists also found that applying an inexpensive antibiotic to the cells appears to correct many abnormalities in the interaction between the cells and developing neurons.

The findings, which focused on support cells in the brain called astroglial cells, appear online today in Nature Communications.

"We have developed a human cellular model for studying brain development in Down syndrome that allows us to carry out detailed physiological studies and screen possible new therapies," said Wenbin Deng, associate professor of biochemistry and molecular medicine and principal investigator of the study. "This model is more realistic than traditional animal models because it is derived from a patient's own cells."

Down syndrome is the most common chromosomal cause of mild to moderate intellectual disabilities in the United States, where it occurs in one in every 691 live births. It develops when a person has three copies of the 21st chromosome instead of the normal two. While mouse models have traditionally been used in studying the genetic disorder, Deng said the animal model is inadequate because the human brain is more complicated, and much of that complexity arises from astroglia cells, the star-shaped cells that play an important role in the physical structure of the brain as well as in the transmission of nerve impulses.

"Although neurons are regarded as our 'thinking cells,' the astroglia have an extremely important supportive role," said Deng. "Astroglial function is increasingly recognized as a critical factor in neuronal dysfunction in the brain, and this is the first study to show its importance in Down syndrome."

Creating a unique human cellular model

To investigate the role of astroglia in Down syndrome, the research team took skin cells from individuals with Down syndrome and transformed them into stem cells, which are known as induced pluripotent stem cells (iPSC). The cells possess the same genetic make-up as the donor and an ability to grow into different cell types. Deng and his colleagues next induced the stem cells to develop into separate pure populations of astroglial cells and neurons. This allowed them to systematically analyze factors expressed by the astroglia and then study their effects on neuron development.

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'Support' cells in brain play important role in Down syndrome