Injection of Virus-Delivered Gene Silencer Blocks ALS Degeneration | Virus World | Scoop.it

Novel spinal therapy/delivery approach prevented disease onset in neurodegenerative ALS disease model in adult mice and blocked progression in animals already showing disease symptoms. Writing in Nature Medicine, an international team headed by researchers at University of California San Diego School of Medicine describe a new way to effectively deliver a gene-silencing vector to adult amyotrophic lateral sclerosis (ALS) mice, resulting in long-term suppression of the degenerative motor neuron disorder if treatment vector is delivered prior to disease onset, and blockage of disease progression in adult animals if treatment is initiated when symptoms have already appeared.

 

Writing in Nature Medicine, an international team headed by researchers at University of California San Diego School of Medicine describe a new way to effectively deliver a gene-silencing vector to adult amyotrophic lateral sclerosis (ALS) mice, resulting in long-term suppression of the degenerative motor neuron disorder if treatment vector is delivered prior to disease onset, and blockage of disease progression in adult animals if treatment is initiated when symptoms have already appeared. The findings are published in the December 23, 2019 online issue of the journal Nature Medicine. Martin Marsala, MD, professor in the Department of Anesthesiology at UC San Diego School of Medicine and a member of the Sanford Consortium for Regenerative Medicine, is senior author of the study. 

 

ALS is a neurodegenerative disease that affects nerve cells in the brain and spinal cord. Motor neurons responsible for communicating movement are specifically harmed, with subsequent, progressive loss of muscle control affecting the ability to speak, eat, move and breathe. More than 5,000 Americans are diagnosed with ALS each year, with an estimated 30,000 persons currently living with the disease. While there are symptomatic treatments for ALS, there is currently no cure. The majority of patients succumb to the disease two to five years after diagnosis. There are two types of ALS, sporadic and familial. Sporadic is the most common form, accounting for 90 to 95 percent of all cases. It may affect anyone. Familial ALS accounts for 5 to 10 percent of all cases in the United States, and is inherited. Previous studies show that at least 200 mutations of a gene called SOD1 are linked to ALS. The SOD1 gene normally serves to provide instructions for making an enzyme called superoxide dismutase, which is widely used to break down superoxide radicals — toxic oxygen molecules produced as a byproduct of normal cell processes. Previous research has suggested that SOD1 gene mutations may result in ineffective removal of superoxide radicals or create other toxicities that cause motor neuron cell death, resulting in ALS.

 

The new approach involves injecting shRNA — an artificial RNA molecule capable of silencing or turning off a targeted gene — that is delivered to cells via a harmless adeno-associated virus. In the new research, single injections of the shRNA-carrying virus were placed at two sites in the spinal cord of adult mice expressing an ALS-causing mutation of the SOD1 gene, either just before disease onset or when the animals had begun showing symptoms....

 

Published in Nature Medicine (23 Dec. 2019):

https://doi.org/10.1038/s41591-019-0674-1