New research from the Texas A&M College of Veterinary Medicine and Biomedical Sciences (VMBS) has discovered that too much of ribonucleic acid, or RNA, can directly impair mitochondria, the microscopic power generators that supply cells with usable energy.
The discovery emerged from experiments involving poxvirus infection, but its relevance may extend much further. According to the researchers, excess RNA has also been observed in some cancers, neurodegenerative diseases, and age-related disorders. The findings could even help scientists better understand how cells respond to RNA-based medicines, including mRNA vaccines.
Published in the Proceedings of the National Academy of Sciences, the study expands the known importance of RNA degradation. Cells routinely dismantle unnecessary, damaged, or defective RNA to regulate protein production and prevent molecular clutter.
“Scientists have long known that RNA degradation helps control protein production and remove defective RNA,” said Dr. Zhilong Yang, a professor in VMBS’ Department of Veterinary Pathobiology. “Our study reveals another important role: it helps cells maintain the energy they need to function properly,” Yang added.
Mitochondria generate energy by maintaining an electrical and chemical gradient across their inner membranes. Disrupting that finely balanced system can reduce cellular respiration, leaving cells with less energy for growth, repair, and other essential activities.
The results indicate that RNA quality control helps defend this energy system. Its role is not limited to managing protein instructions and immune signals. It may also prevent excess RNA from physically interfering with mitochondria.
RNA is not a single type of molecule. Messenger RNA (mRNA) carries genetic instructions from DNA to the cellular machinery that builds proteins. Double-stranded RNA (dsRNA) often appears during viral replication and can warn the immune system that an infection is underway.
Viruses can produce enormous quantities of RNA after taking control of a cell. If that material accumulates faster than the cell can remove it, the buildup may impair mitochondria and weaken energy production.
Scientists already knew that excess dsRNA could provoke powerful immune responses. What surprised the researchers was evidence that too much mRNA, an ordinary and indispensable part of healthy cells, could also become damaging.
“MRNA is a normal component of our cells, but it seems like with many good things, if we get too much, that can become a problem for the cell. When too much RNA builds up, including mRNA, it can damage the mitochondria and interfere with the cell’s ability to produce energy,” Yang said.
