Mitochondria-associated microRNAs in rat hippocampus following traumatic brain injury

Traumatic brain injury (TBI) is a major cause of death and disability, but the molecular reasons are not well known. This study looks at microRNAs (miRNAs), small molecules that regulate genes, and their connection to mitochondria after TBI in rats. The researchers found that proteins needed for miRNA processing are present in mitochondria. They also discovered that certain miRNAs are more common in mitochondria than in other parts of the cell. After a brain injury, the levels of some miRNAs changed in both the mitochondria and the rest of the cell. This suggests that mitochondria-associated miRNAs might have a role in how the brain responds to TBI.

• 1
  The miRNA processing proteins Argonaute (AGO) and Dicer are present in mitochondria fractions from uninjured rat hippocampus, suggesting functional RNA-induced silencing complexes are present.
• 2
  A subset of miRNA is enriched in mitochondria relative to cytoplasm, indicating a specific localization under normal conditions.
• 3
  Following CCI, levels of miR-155 and miR-223, both of which play a role in inflammatory processes, are significantly elevated in both cytoplasm and mitochondria.