The Fountain of Youth

Sestrin molecule

Scientists at University of California, San Diego School of Medicine, are currently looking at the protein sestrin, to see how it affects signaling pathways which  affect aging.  Sestrin is highly conserved across many different species, ranging from mammals to Drosophila melanogaster…better known as the fruit fly.  Being in a wide range of organisms makes sestrin a very important candidate for research on aging.  Often study findings in fruit flies can be can be generalized to humans.

Sestrin, stress, and aging

Sestrin is regulated by stress levels in the cell, when a cell begins to experience stress, sestrin production is increased. Scientist have know about the increase of sestrin during stress for a while, but couldn’t explain the function of the greater concentration of sestrin in the cell until recently.  From looking at Drosophila it was found that sestrin functions as an activator of AMP-dependent protein kinase (AMPK) and inhibitors of Target of Rapamycin (TOR). From looking at model organisms such as C. elegans and Drosophila it was found that the main role of the AMPK and TOR signaling pathways is to control aging and metabolism.  The AMPK pathway is extremely complex; its simplified function is to act as a master regulator of cellular metabolism.  While TOR is responsible for maintaining the balance between protein synthesis and degradation based off of nutritional quantity and quality.  It is currently thought that calorie restricted diets may control the TOR pathway to combat the effects of aging.

complex cellular pathways involved in aging

What does sestrin do?

To look at the function of sestrin scientist made a knockout Drosophila or a fly who was not expressing the genes for sestrin.  In Drosophila sestrin is located on a single gene.  When the sestrin gene was inactivated scientist saw an under regulation of the AMPK and over regulation of the TOR pathways, this confirms the regulatory role of sestrin in these two systems. The pathological effects of a deficiency of sestrin can be seen in Drosophila as an accumulation in triglycerides, cardiac arrhythmia and muscle degeneration.  These same pathological effects can be seen in humans.  Finding a way to control these pathological effects could lead to way to greatly increase the human life span.

So how does this relate to me?

…besides all these cool pathways in my body that regulate how fast I will age?  If we can control the regulation of our TOR and AMPK signaling pathways we can control one aspect of our aging.  The end hope is that from this research scientist will be able to develop a way to slow aging in order to treat degenerative disorders, such as sarcopenia and Alzheimer’s. Since the beginning of time scientists have been searching for that fountain of youth.

A few critters in the animal world have found ways to combat the effects of aging.

a tortoise exemplifies a model organism to study the mechanisms of aging

Maybe we should take a closer look at species such as orange roughy and tortoise that both have extremely long life spans.

By comparing protein profiles between long living critters and humans scientist may be able to unlock how their bodies

combat aging.  Their might be a time in the future when it is not uncommon to live to be over a hundred years old.