HSCI researchers discover self-healing mice

Turning on a single dormant gene in mice gives them heretofore known powers of regeneration, found a team of researchers led by HSCI Executive Committee member George Daley, MD, PhD. The gene, Lin28a, is normally active during embryo formation, but if re-expressed in mice up to six weeks old, the animals gain the ability to regrow hair and repair soft tissues.

The investigators found that by engineering a fully-grown mouse to express Lin28a, they could speed up the animal’s cellular metabolism, causing it to function like that of a much younger, developing animal. When the researchers perforated the ears or clipped the toes of the Lin28a mice, the lost tissue kept regenerating.

“Efforts to improve wound healing and tissue repair have mostly failed, but altering metabolism provides a new strategy which we hope will prove successful,” said Daley, who is also director of Boston Children Hospital’s Stem Cell Transplantation Program.

Further experiments, published in the journal Cell, showed that bypassing Lin28a and directly activating an animal’s cellular metabolism with a small molecule also had the effect of enhancing wound healing. This suggests the possibility of inducing regeneration and promoting tissue repair with drugs.

Lin28a didn’t universally induce regeneration in all tissues. Heart tissue showed little effect, and while the researchers were able to enhance the regrowth of finger tips in newborn mice, they could not in adults.

Lin28a could be a key factor in constituting a healing cocktail,” said PhD candidate Shyh-Chang, “but there are other embryonic factors that remain to be found.”