Research Reveals Ways Neurons are Regenerated in Starfish
By Jocelyn DuffyMedia Inquiries
- Associate Dean for Communications, MCS
Carnegie Mellon University biologists have discovered a mechanism that underlies the regeneration of neurons in starfish, showing for the first time that starfish can regenerate their nervous system. Their findings, published in eLife, could provide a pathway to future research on neuronal regeneration in humans.
Some animals are known for their ability to regrow – or regenerate – body parts following dramatic injury. Starfish are among the most famous and dramatic examples, being able to grow an entire new body from just a single arm. Starfish also have the ability to regenerate neurons, something not seen in many animals. And other species, including humans, have little or no ability to regenerate.
Starfish, humans and other vertebrates share a number of similarities in their early development, genome organization and gene content. Carnegie Mellon biologist Veronica Hinman studies starfish and their mechanisms of development, and her lab was curious to find out what it was in the cells and genes of starfish that allowed them to regenerate.
“If we know what lies within starfish that allows them to regrow whole new bodies from limbs, we can compare that with what is in the cells and genes of human to see what is similar and different,” said Hinman, the Dr. Frederick A. Schwertz Distinguished Professor of Life Sciences and Head of the Department of Biological Sciences at Carnegie Mellon.
While working to better understand the science of regeneration in starfish, Minyan Zheng, then a graduate student in Hinman’s lab, and researcher Olga Zueva were able to show that starfish could not just regenerate their body, they could correctly regenerate their nervous system — something that very few animals can do.
The researchers found that when neurons were injured in the starfish, they began to express the gene sox2, which caused cells to re-enter the neurogenesis program seen during development and form differentiated neurons in their brain. This demonstrated that starfish revert to developmental programs rather that use novel regeneration pathways to regrow neurons.
The involvement of sox2 in neuronal regeneration is significant because this gene also is implicated in coaxing mature human cells into induced pluripotent stem cells (IPS) in cell culture.
“In development, the starfish uses orthologous genes to its vertebrate sister species. These findings may allow for the future understanding of how embryonic neurogenesis could be induced from other adult cell types in humans,” said Hinman.
“In humans, full recovery from traumatic brain injury, whether it be from an accident or an illness, is difficult and often impossible. If we could regenerate the brain cells that are no longer functioning, we could help to improve recovery from these devastating injuries.”
Researchers in Hinman’s lab are now seeking to determine how the sox2 gene become activated following injury and how the gene resets the developmental neurogenesis program in starfish.
The Hinman lab’s research on starfish regeneration was funded through seed grants from the Kaufman Foundation and the DSF Charitable Foundation (to Hinman and Chemical Engineering Professor Kris Dahl). This work was also supported by the National Institute of Health’s National Institute of General Medical Sciences (1R24OD023046) and the National Science Foundation (IOS 1557431).
Zheng is a postdoctoral researcher at Harvard Medical School, working with David Sinclair in the field of aging, cell programming and regeneration.