Sea cucumbers may one day help us learn to fix ourselves

Sea cucumbers are the champions of organ regrowth because they direct their wound healing abilities towards restoring their organs, according to research published in the online open access journal, BMC Developmental Biology.

The discovery that Holothuria glaberrima uses similar cellular mechanisms during wound healing and organ regeneration gives us the opportunity to discover how to repair our own wounds and, perhaps eventually, how to regenerate body parts.

The research was carried out by the investigators José San Miguel-Ruiz and José García-Arrarás, at the University of Puerto Rico. "Sea cucumbers should be viewed as the tissue regeneration equivalent of the squid for our knowledge of nerves and Drosophila for genes and the genome. They can help us learn to fix ourselves," commented Professor Garcia-Arraras. "Many people, including scientists, regard sea cucumbers and other echinoderms like star fish and brittle stars as bizarre, exceptional outcasts because of their regenerative abilities. But we've shown that they use the same 'ordinary' mechanisms and processes to both regenerate and heal wounds."

All animals possess some kind of tissue repair mechanism. The sea cucumber, H. glaberrima, belongs to a group of marine animals that are well known for their ability to regenerate, along with the axolotl salamander, which is also famous for regrowing lost limbs. The scientists made observations over a four-week healing period and found that sea cucumbers healed up rapidly after receiving a 3 to 5 millimetre cut along the body wall. The repair process involved special cells called morula cells moving to the injury site and full repair was achieved after just a couple of weeks. The cellular events observed during the healing of sea cucumber muscular, nervous and dermal tissues that correspond to those observed during intestinal regeneration include extracellular matrix remodeling and the dedifferentiation of muscle cells.

Although all animals have wound repair processes, not all regenerate injured or lost body parts. There must be some unusual properties of the healing processes found in animals capable of organ regeneration. So it remains to be seen at a molecular level what limits healing processes being used for regeneration by all animals in all tissue.

"Many of these regenerative mechanisms are the same as those being used by other animals to heal and repair - this includes us humans, "concluded Professor Garcia-Arraras. "Sea cucumbers will probably provide us with the key to deciphering how to regenerate our tissues, or at least find out what is needed to do this."