(This article forms a part of the Science for All newsletter that takes the jargon out of science and puts the fun in! Subscribe now!)
A biosynthetic ‘clock’ keeps the body’s cells from getting old or in other words, reaching normal levels of deterioration related to ageing. Human lifespan relates to how quickly individual cells age. Recent research has shown that cells follow two distinct paths during ageing, and these are controlled by a central, genetic regulatory circuit. Manipulating these processes can be used to extend the lifespan of cells. Cells, including those of yeast, plants, animals and humans, all contain gene regulatory circuits that are responsible for many physiological functions, including ageing.
Cells follow a variety of molecular changes through their entire lifespan until they eventually degenerate and die. But cells of the same genetic material and within the same environment can travel along distinct ageing routes. About half of the cells age through a gradual decline in the stability of DNA, where genetic information is stored. The other half ages along a path tied to the decline of mitochondria, the energy production units of cells. Thus directing the cell’s journey among these paths can significantly influence ageing.
From its normal role of functioning like a toggle switch, these regulatory circuits can be engineered to generate a negative feedback loop to stall the ageing process. The rewired circuit operates as a clock-like device, called a gene oscillator, that drives the cell to periodically switch between two detrimental “aged” states – or pathways--avoiding prolonged commitment to either, and thereby slowing the cell’s degeneration. These advances resulted in a dramatically extended cellular lifespan, setting a new record for life extension through genetic and chemical interventions.
From the Science pages
Is the core of Mars solid or liquid? Find out here.