Link: https://www.cnn.com/2024/02/09/health/why-autoimmune-disease-affects-more-women-study-scn/index.html
Excerpt:
Why women are at greater risk of autoimmune disease such as multiple sclerosis, lupus and rheumatoid arthritis is a long-standing medical mystery, and a team of researchers at Stanford University may now be a step closer to unraveling it.
How the female body handles its extra X chromosome (the male body has just one plus a Y chromosome) might be a factor that helps explain why women are more susceptible to these types of disorders, a new study has suggested. The predominantly chronic conditions involve an off-kilter immune system attacking its own cells and tissues.
While the research involving experiments on mice is preliminary, the observation, after further study, may help inform new treatments and ways to diagnose the diseases, said Dr. Howard Chang, senior author of the paper published in the journal Cell on February 1.
….
Other researchers had focused on the disorders’ “female bias” by analyzing sex hormones or chromosome counts. Chang instead zoned in on the role played by a molecule called Xist (pronounced exist) that is not present in male cells.
The Xist molecule’s main job is to deactivate the second female X chromosome in embryos, ensuring that the body’s cells don’t get a potentially toxic double whammy of the chromosome’s protein-coding genes.
“Xist is a very long RNA, 17,000 nucleotides long, or letters, and it associates with approximately almost 100 proteins,” Chang said. Xist molecules work with those proteins to shut down gene expression in the second X chromosome.
Author(s): Katie Hunt
Publication Date: 9 Feb 2024
Publication Site: CNN Health