A group of mice displaying hallmark symptoms of Alzheimer’s disease had their symptoms reversed after they were given a compound developed by a group of St. Louis University researchers, a new study finds.
The study is the first, the researchers believe, to look at the power of antisense compounds at reducing brain inflammation and aiding in memory revival. Antisense is a strand of molecules that binds to RNA, which, through a long string of events, eventually results in switching off particular genes. The researchers’ study specifically looked at the ability of antisense oligonucleotide (OL-1) to prevent worrisome amyloid beta plaques from forming in the brain.
"It reversed learning and memory deficits and brain inflammation in mice that are genetically engineered to model Alzheimer's disease," said lead author Dr. Susan Farr in a statement.
In the U.S. alone, Alzheimer’s disease currently ranks as the sixth-leading cause of death due to its devastating break down of the person’s mental function and sense of self. It’s estimated that by 2050, the number of people living with Alzheimer’s will triple up to some 14 million people. Of those, roughly half will be over the age of 85.
Though they are a long way from offering their treatment option to the general public, as Farr notes that the compound must first pass toxicity tests in humans, the breakthrough finding offers hope that the helpless slide into disease isn’t inevitable. Farr and her colleagues arrived at this conclusion via several tests in lab mice who were genetically designed to overproduce human amyloid beta protein, which naturally occurs in the brain.
Compared with mice that had a wild strain of amyloid beta and mice given random antisense compounds, along with those given specifically OL-1, the researchers put the mice through a series of memory and learning tests. They found the mice that had been given the OL-1 compounds performed dramatically better at each task compared to both the mice with too much amyloid beta, but no antisense, and those that had been given a random compound.
"Our findings reinforced the importance of amyloid beta protein in the Alzheimer's disease process,” Farr explained. “They suggest that an antisense that targets the precursor to amyloid beta protein is a potential therapy to explore to reversing symptoms of Alzheimer's disease."
Fortunately, the point of injection mattered little when it came to the compound’s effectiveness — rats given the antisense through their tail or through an injection directly into their central nervous system, which cuts straight to the blood-brain barrier in their heads, performed equally well on the tests. As Farr points out, the study also upholds the popular theory that amyloid beta protein overproduction is the root mechanism behind Alzheimer’s formation — currently a grossly underfunded disease, according to many researchers in the field.
"To be effective in humans, OL-1 would need to be effective at suppressing production of human amyloid beta protein," Farr said. Further tests are currently in the mix to explore this possibility.
Source: Farr S, Erickson M, Niehoff M, Banks W, Morley J. Central and Peripheral Administration of Antisense Oligonucleotide Targeting Amyloid-β Protein Precursor Improves Learning and Memory and Reduces Neuroinflammatory Cytokines in Tg2576 (AβPPswe) Mice. Journal of Alzheimer’s Disease. 2014.