Researchers identify possible target for a type of sporadic ALS

Tuesday, August 30, 2022

Researchers have published two papers describing how they identified a potential new pathway for treating a sporadic form of amyotrophic lateral sclerosis (ALS). The studies were published as part of a cooperative research agreement between the National Institute of Neurological Disorders and Stroke (NINDS), part of the National Institutes of Health, and the Switzerland-based biotechnology company GeNeuro Inc.

One unusual side effect of hundreds of thousands of years of evolution is that the human genome now contains DNA sequences from ancient retroviruses — referred to as human endogenous retroviruses (HERVs). Though most remain dormant, reactivation of HERVs have been implicated in several neurodegenerative diseases, including ALS.

The first of these papers shows that a specific HERV produces a protein that can be found in the cerebrospinal fluid (CSF) of people with ALS. This protein, called HERV-K ENV, is toxic when added to neurons grown in laboratory dishes. In addition, a special kind of mouse genetically designed to create HERV-K ENV develops symptoms very similar to ALS. Adding the CSF from people with ALS to lab-grown neurons resulted in damage to the cells. When a synthetic antibody designed specifically to recognize HERV-K ENV was added as well to those neurons, the toxic effects were reduced. These findings together suggest that the improper activation of the HERV-K ENV gene could be the cause of the symptoms seen in certain cases of sporadic ALS.