Study Links Cellular Recycling Process To Beneficial Effects Of Enduring Mild Stress

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A recent study by researchers at Sanford-Burnham Prebys Medical Discovery Institute (SBP), found that a cellular process known as autophagy is significantly involved in the process of providing the benefits of temporary stress. The study creates new avenues to pursue treatments for neurological disorders like Huntington's disease.

It has been clear to biologists for decades now that enduring a short period of mild stress makes simple organisms and human cells better able to survive additional stress later in life. Autophagy is described as a means of recycling the old or broken parts of cells so as to enable the reuse of their components in making new molecules or burned for energy. Previous studies have linked the process with longevity, but the recent study suggests that long life and stress resistance are connected at the cellular level, according to Medical Express.

"We used to test the importance of autophagy in becoming stress resistant.They are a great model system because they are transparent, so you can easily observe what goes on inside them, most of their genes and molecular signaling pathways have functional counterparts in humans, and they only live a few weeks, which greatly facilitate measuring their life spans," lead author and staff scientist at Hansen's lab, Caroline Kumsta, Ph.D. said.

The researchers incubated the C. elegans - tiny roundworms used to study fundamental biology - at 36 °C for one hour. This is substantially above the temperature they are already used to. After this exposure to heat, the researchers found that autophagy rates increased throughout the tissues of the worms.

Interestingly, when they exposed these heat-primed - longer heat shock worms to another few days later, the researchers discovered that the worms deficient in autophagy failed to benefit from the initial mild heat shock. The researchers inferred that a mild heat stress could also improve the worms' ability to handle another condition that worsens with age-buildup of aggregated proteins, which is somewhat stressful for cells.

To test this hypothesis, the researchers used worms that model Huntington's disease. Huntington's disease is a fatal inherited disorder caused by neuronal proteins that stick together and build up into big clumps as patients grow older. The condition leads to degeneration throughout the brain, according to Science Daily.

The researchers also found that when worms that make similar sticky proteins in different tissues are exposed to mild heat shock, the number of protein aggregates reduces. This suggests that a limited amount of heat stress is capable of reducing toxic protein aggregation. The findings of the study further reiterate the popular, saying that "What doesn't kill you makes you stronger."