Alzheimer's affects about 12 million people worldwide. Lithium may have a potential role in treating Alzheimer's. Lithium targets an enzyme called GSK-3 that facilitates the modification of both the proteins found in Alzheimer's patients. Identification of GSK-3 as a target could help in developing other drugs that disrupt the production of both proteins.
Another advantage to lithium is that it does not disrupt the processing of another protein called notch, as do other potential Alzheimer's drugs. Notch is vital for the production of blood cells.
The drug has been used for decades to treat manic depression. Alzheimer's is marked by the buildup in the brain of one protein, called amyloid beta, outside nerve cells and a second, called tau, that forms tangles in the cells. Many scientists believe that the accumulation of amyloid beta causes the debilitating effects of the memory-robbing disease.
The recent issue of the journal Nature has reported that in mice experiments, Lithium blocks the production of proteins that form deposits in the brains of Alzheimer's patients. Lithium, though widely used to treat mental problems does have many side effects, including kidney damage.
"Potentially, lithium could be used to reverse both the pathological features of Alzheimer's disease," said Dr. Peter Klein of the University of Pennsylvania who co-authored the current study. "It seems you could block with a single medicine both of the major structural manifestations of the disease. This would be the first time that has been shown," said Dr. Sam Gandy, director of the Farber Institute for Neurosciences at Thomas Jefferson University in Philadelphia.
Klein and his colleagues overproduce a protein that when modified forms amyloid beta in mice. The mouse experiments showed that lithium disrupts that modification process. They also showed that lithium disrupts the modification of tau. Currently it is unclear what role tau plays in cellsin the progression of Alzheimer's.
Alzheimer's disease usualy starts at the age of 60 years and involves the parts of the brain that control thought, memory, and language. At present we do not know what causes Alzheimer's and there is no cure.