Research Roundup: gene therapy for inherited blindness, urea implicated as a major cause of dementia and more!

Welcome to this week’s Research Roundup. These Friday posts aim to inform our readers about the many stories that relate to animal research each week. Do you have an animal research story we should include in next week’s Research Roundup? You can send it to us via our Facebook page or through the contact form on the website.

  • FDA approves gene therapy to treat inherited form of blindness. The therapy, called Luxturna, is a genetically modified virus that shuttles a healthy gene into the eyes of patients born with retinal dystrophy, a rare and heritable condition that destroys cells in the retina and can result in blindness. Tests with patients have proven dramatic, enabling them to see their parents’ faces and ride bicycles; however, the therapy is expected to be prohibitively expensive. The foundations for this groundbreaking treatment were discovered and tested through extensive research with animal models such as mice.

  • Gene-editing breakthrough found to minimize hearing loss in mice could help humans. Researchers used CRISPR-Cas9, a gene-editing technology, to prevent hearing loss in a mouse model of human genetic deafness. Dr. Liu, at Harvard University, and his colleagues, worked with Beethoven mice, named for the composer who gradually became deaf, and found that it was possible to edit out the “bad” dominant gene causing gradual deafness, allowing the “good” gene to be dominant. Researchers caution many diseases have been cured in mice but did not have the same results in people. Although in this case, they are hopeful since the same mutation leads to progressive hearing loss in both mice and humans. Further study, including using this technique in larger animals, is needed before it can be applied to human patients. This study was published in Nature.
  • Muscular Dystrophy research at A&M gets FDA approval for human clinical trials.  Duchenne muscular dystrophy (DMD) is a rare, genetic muscle-wasting disease usually found in boys and diagnosed between the ages of three and five years old. As the disease progresses, patients often lose the ability to walk by their early teens and succumb to respiratory or heart failure by their early 20’s. Successful gene transfer therapy in animals, including dogs that have Duchenne muscular dystrophy, has led to FDA approval to start a clinical trial in human patients. Dr. Eleanor M. Green, Dean of the veterinary school at Texas A&M, said “I am proud of this development and of our animal researchers and outstanding faculty and staff who are working to solve the mystery of this dreadful disease. Their ethical cares… treats these animals as the heroes that they are in support of finding a cure for this disease that affects humans and dogs alike.”
Kyle’18 and “Astro”. Photo Credit: Texas A&M University
  • A potentially major cause of dementia discovered. First in 2016, and now in 2017, a group of researchers at the University of Manchester in the UK, have found that the buildup of urea in the brain, is linked to two of the seven major types of age-related dementia — Alzheimer’s and Huntington’s disease. When proteins are broken down, urea and ammonia are byproducts — and can build up in the body if the kidneys are unable to eliminate them. The buildup of urea to toxic levels (4x higher than usual) may contribute to the onset of dementia. The research was, in part, due to the use of transgenic sheep. Published in the journal PNAS.
  • Repeated insults to the gut linked to chronic disease. Mild food poisoning usually clears up without major medical intervention. In a project that took 8 years to complete, a team of researchers, using a mouse model of mild food poisoning, have found that repeated bouts of food poisoning led to the onset of progressive and irreversible inflammatory bowel disease. The lead researcher on this project, Dr. Jamey Marth, stated “Food contamination at these low bacterial levels is likely to be more common than we recognize, while symptoms could be nonexistent or mild and disappear in a day or two without treatment. Repeated over time, we find that such minor infections are sufficient to trigger disease months and perhaps years later, depending upon the number and timing of infections an individual has experienced over his or her lifetime.” Published in the journal Science.