By Ketul PatelThe Daily Northwestern
Regrowing a missing arm may be as easy as flipping a switch. A genetic switch, that is.
Hans-Georg SiMonday, a pediatrics professor at Northwestern’s Feinberg School of Medicine, is trying to pinpoint the genes that help salamanders regenerate damaged tissues and organs, then hopefully match them to similar genes in humans. The discovery, he said, might one day allow people to regenerate limbs, bone and tissue without scarring.
The idea is not as far-fetched as it might sound, Simon said.
“We think as humans that regeneration is spooky or science fiction, but there are more species on Earth that have the ability to regenerate than not,” he said.
With this research, people who have lost arms or legs in industrial accidents will be able to regrow them, as will soldiers who lost limbs in combat, he said. People with any type of degenerative muscle disorder could potentially replace weakened muscles.
Humans once had the ability to regenerate, Simon said. In the past, babies who received heart surgeries as embryos and were replaced in the womb did not have scars on their hearts once delivered, offering proof for humans’ ability to regenerate.
There is a genetic “switch” that aids limb formation but is turned off after humans develop fully, he said. This switch remains on for salamanders, and Simon said he wants to research the effects of keeping it on in humans.
The discovery of this switch would help reduce deaths related to heart problems, Simon said. Some of the problems with heart disease come after the heart attack, when the heart cannot regenerate muscles.
“When the heart heals, it heals by scarring,” he said. “Muscles are replaced by scars, and a scar obviously can’t pump blood – it’s not a functional muscle.”
Dr. David Gardiner, a researcher of developmental and cell biology at the University of California at Irvine, said limb regeneration is a distinct possibility in the future. He has also studied regeneration using salamanders and frogs.
Gardiner said he receives many phone calls from people who would benefit from the regeneration. He said there is urgency for the research because it can help many people, but it will take time.
“By the time we finally get to the point and somebody figures it out, it won’t be as amazing a moment as it would be if it happened today, ” he said. “We’ll have made so much incremental progress by then.”
Simon said he agreed.
“We know what all the genes are, but we don’t know what they do,” he said. “If we know which genes play a role in limb formation, perhaps they play a role in limb regeneration.”
Following this logic, Simon is studying Tbx genes, which are “uniquely active” in limb formation, he said.
In March, Simon received a $3.7 million grant from The Department of Defense’s Defense Advanced Research Projects Agency as part of a national team of researchers studying regenerative medicine.
The program helps coordinate research among people who have not previously worked together, said Dr. Jon Mogford, program manager at DARPA,
“To achieve the program goal of scarless wound healing and tissue restoration, we have brought together scientists from multiple fields including clinicians, cell biologists and tissue engineers who previously have not worked on the problem in a coordinated fashion,” Mogford said in an e-mail.
Reach Ketul Patel at [email protected].
