Why are telomeres important for aging?

Telomeres are crucial for aging because they shorten with each cell division. Telomeres are repetitive sequences of DNA located at the ends of chromosomes, and their primary function is to protect the chromosome from deterioration and from fusion with other chromosomes. Every time a cell divides, the enzymes that replicate DNA cannot replicate the ends of the chromosomes completely, leading to a gradual shortening of the telomeres.

This shortening process ultimately limits the number of times a cell can divide, known as the Hayflick limit. When telomeres become too short, cells can enter a state called senescence, where they no longer divide, or they may undergo programmed cell death, known as apoptosis. This accumulation of senescent cells is associated with various age-related diseases and contributes to the overall aging process.

Understanding telomeres' role in cell division and aging helps to elucidate key mechanisms behind cellular longevity and the biological pathways that contribute to the aging process.