weekly blog--one for the ages
While the nation was celebrating President’s Day earlier this week, I went on an archeological dig at Massachusetts General Hospital in search of the brain’s ancient immune system. We were cruising through research on molecules known as antimicrobial peptides that are found in all forms of life and play an important role in protecting the human brain.
After surfing through paper after paper, we realized that one of these molecules, known as LL-37, looked a lot like a molecule called amyloid-beta, which forms the sticky plaques that tend to build up in the brains of people with dementia. And then it hit us…What if those sticky plaques were actually an effort to protect the brain by encapsulating foreign invaders?
The idea was that the brain was producing amyloid for much the same reason an oyster forms a pearl — for self-defense. That was a pretty radical idea. For decades, most scientists thought amyloid-beta was no more than a toxic waste product. But the researchers on our team suspected amyloid-beta was usually good — unless the brain started making too much. Then it could kill brain cells and lead to dementia.
The question now became: what's causing the glitch in the brain's ancient immune system? One possibility...it was overreacting to viruses and bacteria that get into the brain. Another...the system could be getting confused and attacking healthy cells — a lot like what happens in diseases like lupus or multiple sclerosis.
If either idea holds up, it may be possible to interrupt the process before it causes Alzheimer's. Stay tuned because this approach may also pave the way for curing schizophrenea and other brain-related disorders.