National Institutes of Health (NIH) scientists have uncovered how the processes of healing and aging are connected through researching the regeneration of new bodies by small marine creatures known as Hydractinia symbiolongicarpus.
“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,” Charles Rotimi; director of the Intramural Research Program at the National Human Genome Research Institute (NHGRI), a part of NIH; said in a recent NIH news release. “Such findings have great potential for providing novel insights into human biology.”
Scientists sequenced the RNA of Hydractinia that inhabit hermit crabs’ shells and are able to regenerate a complete new body from only its mouth, according to the news release. The scientists discovered a chemical signature linked to senescence, the biological aging process, just as the Hydractinia were starting to regenerate new bodies.
The release stated that understanding human health and disease depends on unraveling the evolutionary roots of basic biological processes like aging and healing. Humans are capable of regenerating in some ways, such as mending a fractured bone. Other creatures, including salamanders and zebrafish, have the ability to regenerate various organs and replace entire limbs. The most extreme regenerative capacities, like the ability to develop a brand-new body from a single tissue fragment, are frequently found in animals with simple bodies such as Hydractinia.
A unique subset of stem cells for regeneration have already been discovered in Hydractinia, according to the release. Stem cells are helpful in the development of new body components because they can differentiate into different cell types. While stem cells primarily function during development in humans, they are utilized throughout the lifespan of highly regenerative species such as Hydractinia.
The bottom trunk of Hydractinia’s body stores the stem cells that promote regeneration, the release said. The mouth, which is located away from the stem cells, develops a new body when the researchers remove it. When an organism is injured, some highly regenerative creatures' adult cells have the ability to transform back into stem cells. This is in contrast to human cells, which are fixed in their destinies. Unfortunately, the mechanism underlying that transformative ability is unclear. Scientists hypothesize that Hydractinia must produce fresh stem cells, and the researchers have looked for chemical cues that might be controlling the process.
The NIH study was published in Cell Reports.
