ALS, Alzheimer's Insights Could Improve Treatment

MONDAY, Oct. 20 (HealthDay News) -- New discoveries in amyotrophic lateral sclerosis (ALS), also called Lou Gehrig's disease, and Alzheimer's disease could bring new hope to patients, scientists say.

In Alzheimer's, blocking a particular enzyme appears to improve memory and learning, a U.S. team says. And, in ALS, transplanting a type of stem cell can slow the degeneration of nerve cells, according to another study.

Both studies were published in the Oct. 19 online edition ofNature Neuroscience.

In the first report, researchers looked for ways to treat mice with an ALS-like condition.

"The study was designed to target a region where respiratory motor neurons reside -- the cervical spinal cord," explained lead researcher Dr. Nicholas Maragakis, a neurologist at Johns Hopkins University School of Medicine. "This site was chosen because most patients with ALS die of respiratory failure, and the motor neurons in humans reside in the cervical spinal cord," he added.

The researchers hypothesized that by replacing the diseased form of a common nerve cell called an astrocyte with a healthy version, they might preserve or postpone respiratory decline and thereby improve outcomes for ALS patients.

Maragakis' team found that the transplanted cells did survive in the mouse spinal cord. The ALS-affected mice also survived longer, although they were not completely cured.

The finding appeared to strengthen this new therapeutic approach.

"Astrocytes play a key role in disease progression in ALS models, and therapeutic approaches -- either targeting abnormal astrocytes or replacing diseased astrocytes with normal astrocytes through cell transplantation technologies -- may be relevant," Maragakis said. "The findings also stress that transportation of the enzyme glutamate, which is a primary function of astrocytes, appears to be a key to the neuroprotection offered by the 'normal' astrocytes," he added.

ALS is caused by degeneration and death of motor neurons -- nerve cells that stimulate muscles. However, based on the new findings, Maragakis said that non-neuronal cells, such as astrocytes, may be useful targets for therapy in ALS. That could change traditional treatment and cell-replacement therapies for this disease, he said.

The researchers have already been thinking about ways to deliver cells to ALS patients. "While such replacement strategies are not yet ready for the clinic, the next step is to use human astrocytes in the same ALS rodent model," Maragakis said. "If promising, we may propose future human ALS trials, although this is not imminent," he said.

Dr. Lucie Bruijn, science director and senior vice president of the ALS Association, said the research does hold promise.