Font size:
Print
The Hayflick Limit
Context:
A biomedical researcher renowned for his pivotal discovery regarding cellular ageing, passed away on August 1 at the age of 98.
- His work fundamentally altered our understanding of the ageing process and the lifespan of human cells.
|
What is the Hayflick Limit?
|
Key Highlights:
- Variations in Hayflick Limits Across Species:
- Galapagos Turtles: Cells divide approximately 110 times, correlating with their long lifespan of about 200 years.
- Laboratory Mice: Cells become senescent after around 15 divisions, matching their shorter lifespan of about 2-3 years.
- As cells divide, their DNA is replicated, but each time, the protective telomeres at the ends of chromosomes shorten. Eventually, when telomeres become too short, they can no longer protect the chromosomes, leading to cellular senescence.
- Cellular ageing is a significant factor in the development of age-related diseases and the gradual decline in physical and cognitive functions.
- The relationship between telomere length and lifespan remains complex.
- For example, lab mice have telomeres that are five times longer than those of humans but live 40 times shorter lives.
- Research into telomerase has shown that it might be possible to slow down telomere loss in human cells.
The Role of Telomerase:
- The 1980s introduction of telomerase, an enzyme capable of replenishing telomeres, has offered hope for extending cellular lifespan.
- Telomerase is present in all cells but is active primarily in cancer cells, which is why they often bypass the Hayflick limit.
- Despite successful in vitro studies, practical applications for extending human lifespan through telomerase manipulation are still in development.
