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Keep the circadian clocks ticking


Date: March 27, 2016
Weizmann Magazine Vol. 9

As we age, we can feel ourselves slowing down. It turns out that our circadian clocks—mechanisms encoded in our genes that keep our bodies attuned to day and night—slow down as well.

Dr. Gad Asher of the Department of Biological Chemistry and his research group recently showed that certain substances found in many common foods are linked to the timekeeping abilities of these internal clocks through a group of metabolites whose levels drop as we age.

We get the substances, called polyamines, from food, but our cells manufacture them as well. Dr. Asher and his group knew that polyamines regulate cellular growth and proliferation—processes that are also tied to the functioning of the cells’ circadian clocks. And levels of these substances were known to drop as we age.

Working with mice and cultured cells, Dr. Asher and his colleagues found that, indeed, enzymes that are needed to manufacture polyamines undergo cycles that are tied to both feeding and circadian rhythms of day and night. In mice engineered to lack a functional circadian clock, these fluctuations did not occur. These experiments suggested that polyamines are both affected by and affect the clocks: That is, they are embedded components of our circadian mechanisms.

Blocking polyamine synthesis in young mice slowed down their clocks. Conversely, adding polyamines to the drinking water of elderly mice restored the functions of their slowing circadian clocks—giving hope to the researchers that the same might be possible, one day, for humans. Dr. Asher says, “The ability to repair the clock simply, through nutritional intervention with polyamine supplementation, is exciting and obviously of great clinical potential.”


Dr. Gad Asher is funded by Adelis Foundation, The Estate of Dorothy Geller Ș Samuel M. Soref & Helene K. Soref Foundation, Willner Family Leadership Institute, Yeda-Sela Center for Basic Research. Dr. Asher is the incumbent of the Pauline Recanati Career Development Chair.


Dr. Gad Asher

Dr. Gad Asher