Cell distress chemicals help embryos quickly heal

SAN FRANCISCO — Fruit fly embryos use a molecular distress signal to call for wound healing. Those signals — hyperreactive chemicals known as reactive oxygen species — cause embryos to assemble drawstring-like structures called purse strings that rapidly cinch wounds shut, healing without leaving a scar.

Assembling purse strings is a newfound wound-healing role for reactive oxygen species, cell biologist Miranda Hunter of the University of Toronto reported December 4 at the annual meeting of the American Society for Cell Biology. Previous research has suggested that dead and dying cells spill reactive oxygen species and trigger immune cells to move into the wound to mop up the mess.

In fruit fly embryos, cells blasted by a laser make lots of reactive oxygen molecules and die, but cells neighboring the injury have just enough of the distress chemicals to initiate wound healing, Hunter and colleagues found. Those surrounding cells assemble the protein actin into a ring. A protein called myosin tugs on the actin to contract the ring and draw cells in to close the wound within about an hour.

Learning how fruit fly embryos quickly heal wounds without scarring and inflammation may eventually lead to better wound treatments for people.