The Goldilocks effect in aging research
The finding, which appears in the December 5, 2016, issue of Nature Structural & Molecular Biology , deepens our understanding of stem cell biology and could help advance stem cell-based therapies, especially related to aging and regenerative medicine. "This work shows that the optimal length for telomeres is a carefully regulated range between two extremes," says Jan Karlseder, a professor in Salk's Molecular and Cell Biology Laboratory and senior author of the work. "It was known that very short telomeres cause harm to a cell. But what was totally unexpected was our finding that damage also occurs when telomeres are very long." Telomeres are repetitive stretches of DNA at the ends of each chromosome whose length can be increased by an enzyme called telomerase. Our cellular machinery results in a little bit of the telomere becoming lopped off each time cells replicate their DNA and divide. As telomeres shorten over time, the chromosomes themselve...