Researchers found out how ‘healer’ mice regenerate lost digits and articular cartilage. Is there hope for human beings as well?

Fourteen years ago, holes were cut into several mice’s ears, to assist in their identification in an immunology experiment. A few weeks later, the experiment failed, since the researchers could not distinguish between the two groups of mice. They have all regenerated their ear tissue, and the holes were long gone, with no scar to show. Ever since that time, these mice were termed MRL mice, or Healer mice, and have undergone extensive checks to understand what made them so unique. Last week, a partial answer was found. In the healer mice, the P21 gene, a known cell cycle regulator, is inhibited.

Unlike typical mammals, which heal wounds by forming a scar, the healer mice begin by forming a blastema, a structure associated with rapid cell growth and de-differentiation as seen in amphibians. According to the Wistar researchers, the loss of p21 causes the cells of these mice to behave more like embryonic stem cells than adult mammalian cells, and their findings provide solid evidence to link tissue regeneration to the control of cell division.

“Much like a newt that has lost a limb, these mice will replace missing or damaged tissue with healthy tissue that lacks any sign of scarring,” said the project’s lead scientist Ellen Heber-Katz, Ph.D., a professor in Wistar’s Molecular and Cellular Oncogenesis program. “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.”

That’s a nifty idea, to be sure. I assume the professor refers to medication utilizing the relatively new technology of siRNA molecules, which could inhibit or inactivate genes in specific cells in the body. A previous research by Dr. Dan Peer et al has already shown that siRNA molecules can be delivered to specific cells and alter their functions. There is still time, to be sure, until such medication enters the market, but the future seems inevitable. The only problem right now is the high manufacturing price of siRNA. Still, these molecules were discovered only eleven years ago, and the technology will develop as the need arises.

Will the medicine of the future consist of shots of P21-inhibiting-siRNA? It is yet hard to say. The healer mice may be able to regenerate their articular cartilage and partially regrow digits, but there’s nothing to tell whether or not the same applies for human beings. The only way to know for certain is through future studies by locally inhibiting P21 in mice, and perhaps much later – in human beings as well. But if it would work… Now, wouldn’t that be something?

Source at Wistar Institute

The scientific paper

An article about siRNA

Share on Facebook

Popularity: 35% [?]