Mitochondria mistakenly incorporate RNA building blocks into their DNA when DNA building blocks are scarce, leading to instability and inflammation that may contribute to age-related health issues.
Why it matters: Understanding the molecular mechanisms behind age-related inflammation could lead to new strategies for maintaining health as we age.
The details:
- Researchers from the Max Planck Institute for Biology of Ageing in Germany discovered that when mitochondria lack enough DNA building blocks (deoxyribonucleotides) for replication, they incorporate RNA building blocks (ribonucleotides) instead.
- This error causes instability in mitochondrial DNA (mtDNA), leading to its ejection from the organelle into the surrounding cytoplasm, which can trigger inflammation.
- The study involved analyzing tissue samples from both humans and test animals, revealing that deoxyribonucleotides become less abundant with age, while ribonucleotides are picked up by the mtDNA.
- Evidence of kidney scarring in mice caused by expelled mtDNA supports the idea that mitochondrial errors and ejection of faulty DNA might drive inflammation and associated health issues, such as autoimmune diseases and neurodegenerative conditions.
What they’re saying:
- “Our findings explain on a molecular level how metabolic disturbances can lead to inflammation in cells and aged tissue, and open up new strategies for possible interventions,” said Thomas Langer, a molecular biologist at the Max Planck Institute for Biology of Ageing.
- “There is already a therapy for certain mitochondrial diseases that involves administering DNA building blocks,” noted Dusanka Milenkovic, another molecular biologist from the Max Planck Institute for Biology of Ageing. “However, we do not yet know if it can also alleviate the inflammation that occurs more frequently with age. It would be interesting to test this.”
The bottom line: This research offers promising insights into how we might mitigate some of the negative health impacts associated with aging by preventing mtDNA from making replication errors.
