By Daniel Webster, dWeb.News
Newswise — Researchers at UT Southwestern have identified an immune protein that is linked to Niemann-Pick type C, a rare neurodegenerative condition. Although it was first identified over a century ago, there are still no effective treatments. Nan Yan, Ph.D. study leader and associate professor of immunology, microbiology, says Niemann-Pick disease was never considered an immune disorder. These findings have given it a new perspective. “Niemann–Pick disease typeC, which affects approximately 1 in every 150,000 people around the world, has been long considered a disease of cholesterol distribution and metabolism. This topic is well-studied at UT Southwestern where Michael Brown, M.D. and Joseph Goldstein, M.D. won the Nobel Prize for 1985 for discovering low-density cholesterol (LDL) receptors. This causes the progressive decline of motor and intellectual abilities that characterize Niemann–Pick. Yan’s lab, which does not study cholesterol metabolism, discovered it accidentally while researching an immune protein called STING. This protein, also known as cyclic GMPAMP-AMP synthase, is responsible for sensing DNA and turning on immune genes to fight against viral invaders. UT Southwestern discovered the cGAS enzyme. STING travels to different organelles to perform different tasks before it ends up at lysosomes which are cellular garbage dumps. Yan explains that proper disposal of STING is crucial for an effective immune response. Research from Yan’s lab and others has shown STING travels to different organelles to perform various tasks before it ends up in lysosomes, which serve as cellular garbage dumps. Yan’s team discovered that STING interacts to a protein located on the surface lysosomes. This protein is produced by the Npc1 genes. Yan and his team looked into whether this might be a role. Researchers removed the STING gene from mice that had had the Npc1 gene deleted. The researchers removed the gene for STING from mice in which the Npc1 gene had been deleted. However, animals with both the Npc1- and Sting genes deleted were healthy. Yan and his colleagues discovered that STING signaling can be activated independently from cGAS in Niemann-Pick diseases. These findings expand the role of STING biology beyond its traditional role in host defense against infection. Yan and his colleagues are currently investigating experimental drugs that inhibit STING in order to treat various autoimmune conditions. These compounds could also be useful in Niemann-Pick type C. Yan states that if we can prove that these compounds work in animal models, we may be able offer a treatment for Niemann-Pick patients. Ting-Ting Cho, Xintao, Kun Yang and Jianjun Wu were also part of this study. Joyce J. Repa and a number of other UT Southwestern experts in neuroscience, cholesterol biology, and other sciences contributed to the study. The technical support provided by UTSW’s Whole Brain Microscopy and Proteomics Core and Live Cell Imaging Core was also crucial to this study. Joyce J. Repa is a Regental Professor and holds the W. A. (Monty.) Moncrief Distinguished chair in Cholesterol and Arteriosclerosis Research and Paul J. Thomas Chair In Medicine. Goldstein, a Regental Professor holds the Julie A. Beecherl, Jr. The Paul J. Thomas Chair of Medicine and the Distinguished Chair for Biomedical Research are both held by Goldstein. Yan is the Rita C. & William P. Clements Jr. Scholars in Medical Research. UT Southwestern Medical CenterUT Southwestern is one of the most prestigious academic medical centers in the country. It combines pioneering biomedical research and exceptional clinical care and education. Six Nobel Prizes have been awarded to the institution’s faculty, which includes 26 members of National Academy of Sciences, 16 members of National Academy of Medicine and 13 Howard Hughes Medical Institute Investigators. More than 2,800 full-time faculty members are responsible for pioneering medical advances. They also work hard to translate science-driven research into new clinical treatments. UT Southwestern physicians care for more than 117,000 patients in 80 specialties, more than 360,000 emergency cases, and nearly 3 million outpatient visits each year.
More dWeb.News Health at https://dweb.news/news-sections/health-medical-news/