Horse-derived iPS cells

by Chris Kamel

We've talked often about induced pluripotent stem cells (iPS cells) on this blog -- the transformation of adult terminally differentiated cells into stem cells that can differentiate into various lineages -- mostly in the context of discoveries in mice and potential applications in regenerative therapy for humans. One thing mentioned less often is the use of stem cell technologies for our pets and animal companions. Anew paper published by Dr. Andras Nagy's group at Mount Sinai Hospital and the University of Toronto has established equine iPS cell lines raising the possibility of stem cell therapies for horses.

The work, published today in Stem Cell Reviews and Reports, used the common technique of delivering four key reprogramming genes (c-Myc, Klf4, Oct4 and Sox2) to convert equine fibroblasts into stem cells. They were able to show that these reprogrammed cells expressed certain pluripotency markers, looked similar to human iPS cells, and differentiated more quickly than mouse or human stem cells. Unfortunately, because horse cells aren't commonly used in a lab setting, the authors weren't able to perform the usual tests to determine what cell types were being produced upon differentiation. However, implantation of the equine iPS cells into mice resulted in teratomas containing all three basic cell types indicating pluripotency.

Animal derived iPS cells open some interesting avenues for veterinary medicine. Several other animals have been used to develop iPS cells including monkeys, dogs, pigs, and rabbits. Perhaps, in time, we'll be seeing new regenerative medicines for our dogs and cats based on their own reprogrammed cells. While these are not the first equine iPS cells developed, they are the first to have their pluripotency properly established. The horse also presents a potentially interesting model for human injuries to muscles, joints, and ligaments -- the types of injuries common, but difficult to treat, in these animals. With the development of equine iPS cells, the horse could become integral in pioneering new human therapies.

Also read the media release.