A study from Texas A&M University, published in the Proceedings of the National Academy of Sciences, has found that too much RNA inside a cell can directly damage mitochondria, the structures responsible for generating cellular energy. The researchers showed that when poxviruses generate large quantities of RNA during infection, the buildup can overwhelm the cell's normal RNA cleanup systems and interfere with energy production.
Surprisingly, the damage was not caused by the immune response. Experiments with isolated mitochondria showed that adding RNA directly caused mitochondrial harm even without immune signaling. The team proposes that RNA's negative electrical charge may disturb the electrical gradient mitochondria rely on to produce ATP, the cell's main energy source.
The discovery points to a delicate balance: cells need RNA to make proteins, but too much can become toxic. The authors note that viruses appear to manage this by degrading excess RNA so the infected cell stays healthy enough to support viral replication. The findings could also shed light on aging-related diseases and help guide the design of RNA-based treatments such as mRNA vaccines.