In their quest for the key to unlock the mystery of Alzheimer’s, researchers are taking a closer look at tau. The hallmarks of Alzheimer’s are plaques of the protein beta amyloid and tangles of the protein tau.
Just exactly what causes the plaques and tangles are somewhat of a mystery, as is their exact role in the disease. Most research has been on ways to eliminate plaques, but a study at Columbia University Medical Center, New York, delved into how tau tangles spread in the brain.
Of course, this study was not done on humans—it was based on tau introduced into the frontal lobes of mice. The valuable insight from this study is that tau appears to spread like a virus, or cancer, jumping from neuron to neuron, across synapses, and spreading to other parts of the brain.
This discovery is a clue. According to Dr. Scott A. Small, co-author of the article published in PLoS One, this discovery indicates that in the future early detection and treatment could be used to stop the spread of tau in the human brain. Small said, “It is during this early stage that the disease will be most amenable to treatment. That is the exciting clinical promise down the road.”
Another article published in the February issue of Science Express also compares the spread of Alzheimer’s disease to cancer. In fact, this is a study of how the cancer drug bexarotene has cleared the beta amyloid protein (plaques) from test animals by increasing ApoE. Cognitive function in the mouse models improved.
This is an already developed and tested drug so the process of determining what dose levels would be effective in humans to treat Alzheimer’s may move somewhat faster. The study has a cautionary note for caregivers of people with Alzheimer’s to not ask doctors to prescribe bexarotene for Alzheimer’s. This is an unapproved use of the drug.
I’m not sure why, but for some reason as I reviewed these two articles, I was reminded of a book I read when I was a teenager called Flowers for Algernon. Maybe it was all the talk about experiments on laboratory mice and the way success may not necessarily translate to humans. In Daniel Keye’s book, the story is a series of journal entries written by Charlie, a man with an IQ of 68, who has the same experimental surgery that improved the intelligence of the laboratory mouse, Algernon. After the surgery, Charlie’s IQ skyrockets to genius level. The surgery on Charlie and Algernon has the complete appearance of success—that is until Algernon begins to decline mentally and dies. Charlie’s decline is as sure as Algernon’s, but he requests flowers be placed on Algernon’s grave.
Just like in Algernon, success in mice doesn’t necessarily mean success in humans, but it is a start. By attacking the hallmarks of Alzheimer’s, these two scientific studies show new approaches to stopping Alzheimer’s in its tracks. Science moves slowly and it will be many more years before this discovery will translate to an effective treatment for the 5.4 million Americans with Alzheimer’s.
The goal set during review of the National Alzheimer's Plan is to prevent and effectively treat Alzheimer’s disease by 2025. Although thirteen years seems like a long time, it would be worth the wait if we can place flowers on the grave of Alzheimer’s—not on the graves of those who die from the disease.
Copyright © February 2012 by L. S. Fisher
No comments:
Post a Comment