Scientists posit anti-aging solution based on immortal regenerating sea creature

04 Jul 2023 --- Researchers at the US National Institutes of Health have discovered anti-aging and healing solutions by probing the regenerative properties of Hydractinia symbiolongicarpus, a minute animal living on hermit crabs’ shells.

The sea creature regenerates its entire body from the mouth outward. By sequencing its RNA, the researchers detected a molecular signature associated with the biological aging process once the regenerative process was underway. 

Just as the Hydractinia was beginning to regenerate new bodies, the researchers detected a molecular signature associated with the biological process of aging, also known as senescence. These signals play a key role in reprogramming somatic cells into stem cells.

“Studies like this that explore the biology of unusual organisms reveal both how universal many biological processes are and how much we have yet to understand about their functions, relationships and evolution,” says Dr. Charles Rotimi, director of the intramural research program at the National Human Genome Research Institute (NHGRI), part of NIH. 

“Such findings have great potential for providing novel insights into human biology.”

Healing and aging mechanisms interrelated
According to the study published in Cell Reports, Hydractinia demonstrates that the fundamental biological processes of healing and aging are intertwined, providing a fresh perspective on how aging evolved.

When the researchers remove the mouth of Hydractinia, the mouth grows a new body even though it is located far from where the stem cells reside.

Contrary to human cells, the adult cells of highly regenerative organisms can revert into stem cells when the organism is wounded. As a result, the researchers theorized that Hydractinia must generate new stem cells and looked for molecular signals that could be directing this process.Researchers are now analyzing the evolution of biological processes to understand health and disease (Credit: Cell Reports). 

Unlocking the evolutionary origins of biological processes, such as aging and healing, is essential to understanding human health and disease. For example, humans have some capacity to regenerate, like healing a broken bone or even regrowing a damaged liver. 

Salamanders and zebrafish can replace entire limbs and replenish a variety of organs. However, Hydractinia, which has a simple body, has more elaborate regenerative abilities, such as growing a new body from a tissue fragment. 

Meanwhile, Shiseido has pinpointed the biological mechanisms of special proteins affecting senescence. The beauty brand worked with scientists at the Cutaneous Biology Research Center at Massachusetts General Hospital to understand the occurrence. 

Mapping an ancestral lineage
Humans last shared an ancestor with Hydractinia and its close relatives, jellyfish and corals, that lived over 600 million years ago. These creatures don’t age at all. Because of these factors, Hydractinia can provide crucial insights into our earliest animal ancestors. 

The current study’s researchers theorize that regeneration may have been the original function of senescence in the first animals. However, a regenerative role for senescence does not hold up to findings in human cells.

“Most studies on senescence are related to chronic inflammation, cancer and age-related diseases,” says Dr. Andy Baxevanis, senior scientist at NHGRI and an author of the study. 

“Typically, in humans, senescent cells stay senescent, and these cells cause chronic inflammation and induce aging in adjacent cells. We can learn about how senescence can be beneficial and expand our understanding of aging and healing from animals like Hydractinia.” 

Scientists don’t yet understand how senescent cells trigger regeneration or how widespread this process is in the animal kingdom.

“Fortunately, by studying some of our most distant animal relatives, we can start to unravel some of the secrets of regeneration and aging – secrets that may ultimately advance the field of regenerative medicine and the study of age-related diseases,” Baxevanis concludes.

By Inga de Jong