Alzheimer’s disease could be treated with a drug that has been used for decades, according to new research.
Researchers have found that a type of drug used to induce labor in pregnant women also speeds up the brain’s dysfunctional waste-clearing system.
This is why some call Alzheimer’s and other dementias “dirty brain” diseases, because when the elimination system slows down, toxic waste builds up in the brain, crowding and damaging healthy tissue.
Administering drugs that trigger muscle contractions can restore some of that function, said Dr. Douglas Kelley, a professor of mechanical engineering at the University of Rochester who led the study.
These drugs, which are used to help achieve more than a million pregnancies a year, can be taken in pill form, intravenously or applied topically for $561.
Research at the University of Rochester by Dr Douglas Kelley (left) and colleagues including Professor Tin Du (right) found that a common drug could help restore glymphatic system functions in older brains.
The researchers examined the brain’s waste-removal system, known as the glymphatic system, which begins to decline with age and in diseases such as Alzheimer’s and Parkinson’s.
‘‘This research demonstrates that restoring cervical lymphatic vessel function can substantially rescue the age-associated slower clearance of waste from the brain,’ said Dr. Kelley.
‘“Moreover, this was achieved with a drug that is already in clinical use, offering a potential treatment strategy.”
The study, which was published in the Nature Aging Journallooked at the complex series of tunnels and pumps that the brain uses to remove waste called the glymphatic system.
The system pumps fluid over brain tissue, washing away old cells and proteins that could clog and damage neurons.
In a young, healthy brain, this system works well and is efficient, but it slows down as we age or develop dementia.
One theory about Alzheimer’s is that this slowdown allows the buildup of proteins called beta amyloid.
Amyloid beta is a naturally occurring protein that, in young brains, is processed when it is no longer useful and sent to the body to be processed.
But in Alzheimer’s, bundles of these dysfunctional proteins — a hallmark of the disease — can build up, crowding out and killing healthy brain tissue.
A similar process occurs with a different protein called alpha-synuclein in Parkinson’s.
Dr. Kelley was able to observe how the brain’s waste-removal systems slow with age in mice by tagging the pumps in their brains and recording their function.
He found that in young, healthy mice, these pumps worked rapidly, releasing a near-constant stream of dirty fluid out of the brain.
But in older mice, contractions slowed by about 63 percent, allowing more “dirt” to build up in the brain.
Seeing this delayed pumping, researchers decided to look at a type of drug that has been used for years, called prostanoids.
Prostanoids are drugs that affect prostaglandins, a type of fat that the body produces naturally and that causes muscle contractions, among other things.
These drugs are useful in a wide range of medical situations: from helping to induce muscle contractions during childbirth to treating glaucoma and altering blood flow.
They were used to delivering approximately 31 percent of American babies in 2020 – helping to bring 1,117,612 new people into the world during approximately $561 per dose.
Perhaps the most famous of these is misoprostol, one of two drugs used in medical abortion.
The researchers applied a type of topical prostanoid drug to the necks of the mice, just above the pumps that process waste from the brain. The theory was that this might get the pump muscles working again.
The drug sped up the pumps in older mice, making them as efficient as young, healthy mice at removing old fluid from the brain.
“You can see how this approach, perhaps combined with other interventions, could be the basis for future therapies for these diseases,” Dr. Kelley said.
