MADISON -- The blood-brain barrier -- the filter that governs what can and cannot come into contact with the mammalian brain -- is a marvel of nature. It effectively separates circulating blood from the fluid that bathes the brain, and it keeps out bacteria, viruses and other agents that could damage it.
But the barrier can be disrupted by disease, stroke and multiple sclerosis, for example, and also is a big challenge for medicine, as it can be difficult or impossible to get therapeutic molecules through the barrier to treat neurological disorders.
Now, however, the blood-brain barrier may be poised to give up some of its secrets as researchers at the University of Wisconsin-Madison have created in the laboratory dish the cells that make up the brain's protective barrier. Writing in the June 24, 2012 edition of the journal Nature Biotechnology, the Wisconsin researchers describe transforming stem cells into endothelial cells with blood-brain barrier qualities.
Access to the specialized cells "has the potential to streamline drug discovery for neurological disease," says Eric Shusta, a UW-Madison professor of chemical and biological engineering and one of the senior authors of the new study. "You can look at tens of thousands of drug candidates and just ask the question if they have a chance to get into the brain. There is broad interest from the pharmaceutical industry."
The blood-brain barrier depends on the unique qualities of endothelial cells, the cells that make up the lining of blood vessels. In many parts of the body, the endothelial cells that line capillaries are spaced so that substances can pass through. But in the capillaries that lead to the brain, the endothelial cells nestle in tight formation, creating a semi-permeable barrier that allows some substances -- essential nutrients and metabolites -- access to the brain while keeping others -- pathogens and harmful chemicals -- locked out.
|Contact: Terry Devitt|
University of Wisconsin-Madison