A study published in PLoS on August 27 (apparently as a birthday present to me), reports that researchers have been able to remove the amyloid-beta plaques associated with Alzheimer’s disease. The researchers, by implanting genetically engineered skin cells in the brains of mice. As described in a more accessible write-up in the Harvard Gazette, these implanted cells delivered genes that allowed the brain to clear away the plaques. More below the jump…
The big question now is whether the technique will work in humans. The Gazette reports that similar engineered-cell-implantation methods have moved to human trials for treatment of cancers and other diseases. For Alzheimer’s, apparently one complication is the size of the brain.
The experiments proved that the technique works, but will it work in humans? One major obstacle, Selkoe says, is the larger size of a human brain compared to that of a mouse. That difference will require an increase of amyloid-busting activity throughout a much larger space.
One solution might involve implanting the genes and fibroblasts where they have the best access to amyloid-beta, in the spinal fluid for example, instead of trying to inject them into a small target. The amyloid-killing combo might be put into capsules that would secrete neprilysin into the blood circulating in the brain, eliminating the need to hit an exact spot.
One possibility that they didn’t suggest would be implanting the cells near the hippocampus, a brain area known to be crucial for short-term memory and for consolidation of short term memories into long-term memories. This compromise would probably not stop the overall progression of the disease, but it might give higher quality of life to those suffering with it, if it can extend the period during which they can remember.
This is the most exciting bit of medical research news I’ve read in a long time, partly because as someone with Alzheimer’s in the family, I’m glad to hear anything that brings hope of a possible cure. Also, though, we’re finally seeing the possibility of personalized, genetically engineered cures or treatments for the diseases that have resisted 20th century drug-based medicine. Welcome to the new millennium!
Reducing Amyloid Plaque Burden via Ex Vivo Gene Delivery of an Aβ-Degrading Protease: A Novel Therapeutic Approach to Alzheimer Disease Hemming ML, Patterson M, Reske-Nielsen C, Lin L, Isacson O, et al. PLoS Medicine Vol. 4, No. 8, e262 doi:10.1371/journal.pmed.0040262