Sex differences in mitochondrial gene expression during viral myocarditis

Abstract

Many viruses can infect the heart. Immune cells go to the heart to get rid of the virus but sometimes this response can damage the heart. When immune cells go to the heart it is called “myocarditis,” which means ‘myo’ for muscle and ‘carditis’ for heart inflammation. More men get myocarditis after viral infections than women. When we study viral infection in mice as a model of human disease, we see the same sex differences as in humans. To know why this happens, we gave mice a viral infection and looked at how their hearts changed. We found that a special gene acts like a light switch to turn on the genes that help cell energy factories called “mitochondria.” Females used this light switch to turn on the genes that help mitochondria, but males did not and turned most of these genes off. We learned that the light switch works better in females compared to males, so it may play an important role in protecting female’s hearts during myocarditis. More research is needed to better understand how this light switch works. Understanding how to turn on mitochondria genes in the heart could help doctors also do this in men after a viral infection to prevent myocarditis and save patients’ lives.