Neuroscientists at Friedrich-Alexander-Universität Erlangen-Nurnberg (FAU) have made a groundbreaking discovery concerning certain RNA molecules within nerve cells in the brain. Contrary to the general understanding that RNA molecules are short-lived and constantly regenerated to adapt to environmental changes, these particular RNA molecules persist throughout an individual’s lifetime without renewal. Collaborating with researchers from Germany, Austria, and the USA, FAU scientists published their findings in the journal Science, aiming to unravel the intricate aging process of the brain and enhance comprehension of associated degenerative diseases.
While most cells in the human body undergo regular renewal to maintain vitality, there are exceptions such as those in the heart, pancreas, and brain. These cells endure without renewal throughout life, necessitating sustained functionality. According to Prof. Dr. Tomohisa Toda, Professor of Neural Epigenomics at FAU and the Max Planck Center for Physics and Medicine in Erlangen, aging neurons significantly contribute to neurodegenerative disorders like Alzheimer’s. Therefore, comprehending the aging process and the essential components involved in preserving cell function is pivotal for effective treatment strategies.
In collaboration with neuroscientists from Dresden, La Jolla (USA), and Klosterneuburg (Austria), Prof. Toda’s team identified a pivotal aspect of brain aging. They discovered that specific types of ribonucleic acid (RNA) protecting genetic material endure as long as the neurons themselves, contrary to the short lifespan of most RNA molecules. Utilizing fluorescent markers, the researchers tracked the lifespan of these RNA molecules in mouse brain cells. Remarkably, they identified these long-lived RNAs, termed LL-RNAs, even in two-year-old animals, not only within neurons but also in somatic adult neural stem cells in the brain.
Furthermore, the researchers observed that LL-RNAs predominantly localize within the cell nuclei, closely associated with chromatin, the DNA-protein complex forming chromosomes. This association suggests LL-RNAs’ crucial role in chromatin regulation. To validate this hypothesis, the team conducted in-vitro experiments with adult neural stem cell models, reducing LL-RNA concentration, and observing a significant impairment in chromatin integrity.
Prof. Toda emphasizes LL-RNAs’ importance in long-term genome stability regulation, contributing to the lifelong preservation of nerve cells. Future research endeavors aim to delve deeper into the biophysical mechanisms underlying LL-RNAs’ long-term preservation, elucidating their biological function in chromatin regulation and the effects of aging on these mechanisms.
