Gene discovery could help heal amputated limbs--study

The research conducted by Wistar Institute in Philadelphia and Washington University and sponsored by US National Institutes of Health has revealed that a gene called p21 may naturally cure damaged body parts, as observed in organisms like newts, flatworms and hydra.

The mutated p21 gene is known to help in the healing task in bodily wounds.

Lead researchers, Ellen Heber-Katz, professor at Wistar Institute and Dr. Khamilia Bedelbaeva said, “While we are just beginning to understand the repercussions of these findings, perhaps one day we’ll be able to accelerate healing in humans by temporarily inactivating the p21 gene.”

Test conducted on lab mice
The researchers conducted the examination on Murphy Roths Large (MRL) species of mice that have the ability to partly grow amputated tissues.

For the study, researchers took samples of unharmed skin cells from MRL mice and normal mice to see the effects of growing them in laboratory.

The traits of these cells were then compared with the variations occurring in them later on.

The researchers also examined the activity of p21 gene, which curbs damaged cells from dividing, and determined if healing of injury in genetically engineered mice was different than wound healing in normal mice.

The premise behind the research was to study the cell division, cell repair, and cell re-growing process regulated by the p21 gene.

Results of the study
On analysis, it was found that uninjured cells in MRL mice were similar to those in various mammals and animals like salamanders that have tissue renewing properties.

It was further revealed that the p21 gene is inactive in mouse embryo stem cells.

Hence, both the genetically engineered and MRL mice that lacked the gene showed augmented healing functions, unlike in normal mice with limited curative properties.

Therefore, researchers concluded, “There is a link between how cells prepare for and undergo cell division--the cell cycle and tissue regeneration.”

The findings emphasized the role of p21 gene in tissue repair in mice and might show hope in human cells and tissues too.

However, researchers cautioned, “Even if p21 has a role in human healing a number of additional factors will also play a role.”

The study appears in the journal Proceedings of the National Academy of Sciences.