Cellular Pathway Mediates Longevity Due to Diet

Component of pathway important for nutrient sensing and aging

FRIDAY, May 22 (HealthDay News) -- A component of a nutrient-sensing cellular signaling pathway plays an important role in the increased lifespan resulting from dietary restriction, according to a study published online May 22 in PLoS Genetics.

Di Chen and colleagues from the Buck Institute for Age Research in Novato, Calif., investigated the role of hypoxia inducible factor-1 (HIF-1) in extending lifespan due to dietary restriction in the worm Caenorhabditis elegans. HIF-1 is a target of the nutrient-sensing target of rapamycin pathway known to mediate this longevity, according to the authors.

The researchers found that loss of HIF-1 function extended lifespan under nutrient-rich conditions but not under dietary restriction. Conversely, increased HIF-1 activity reduced the extended lifespan due to dietary restriction. The increased lifespan was associated with lower levels of stress in the endoplasmic reticulum, caused by excessive misfolded or unfolded proteins, the investigators note.

"Thus, our results support the idea that HIF-1-mediated changes in protein homeostasis play a key role in the lifespan extension by dietary restriction," Chen and colleagues conclude. "Our study suggests an important role for HIF-1 as an oncogene in the context of aging and nutrients sensing, which are both key risk factors in tumor formation."

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