We still have a lot to learn about the aging process, but work on the model organism C. elegans has unveiled that there may be a genetic ‘switch’ that occurs with reproductive maturity and contributes to cellular deterioration.
Work on C. elegans has already advanced study of the molecular basis of aging, perhaps the most well known being Cynthia Kenyon’s discovery that a mutation in the gene DAF-2 could double the worm’s lifespan; uncovering the first metabolic pathway that might regulate aging, the IGF-1 signalling pathway. A new study on the organism has found that germline stem cells (that make reproductive cells), flip a switch once adulthood has been reached which turns off some of the quality control mechanisms that protect against things like incorrect protein folding. For some reason maturity in C. elegans seems to trigger this response, which reduces protective measures in adult cells and contributes to age related changes. This switch affects something called the ‘heat shock response’ – a process which protects the cell against heat fluctuations and ensures correct folding among other things.
‘Once the germline has completed its job and produced eggs and sperm necessary for the next generation of animals – it sends a signal to cell tissues to turn off protective mechanisms, starting the decline of the adult animal.’
This system helps ensure an organism delivers healthy offspring, but it appears that it is tuned down once this job has been achieved. Findings like this don’t necessarily translate to humans, but fundamental cellular pathways are usually well conserved so it may well prove to be relevant. If humans are found to undergo similar changes with time, flipping a similar switch back on may have beneficial effects.
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