Stem cells draw a lot of attention for their potential to benefit human health. However, though less publicized, significant advances are being made in the realm of stem cell veterinary medicine. This past week researchers announced that they have been able to successfully generate stem cells from the skin of an adult female horse. The cells generated are reported to have a greater differentiation potential than previous lines of equine stem cells due to a more naïve state. This research represents yet another advance towards developing personalized medicine in both human and veterinary medicine.
Stem cells can be described as the cellular “blank slates” or “wild cards” of the body. These are cells that have the potential to transform into an entirely different kind of cell such as a neuron, a red blood cell, or a skin cell. Different kinds of stem cells have different levels of transformative abilities. Embryonic pluripotent stem cells have the potential to differentiate into any of the body’s 200 different kinds of cell types with the exception of those specifically required for the formation of a fetus. Hematopoietic stem cells by contrast can only differentiate into cell types associated with the circulatory and immune systems.
Much of the controversy over stem cells is due to the use of embryonic stem cells. Embryonic stem cells are pluripotent, and therefore offer researchers the greatest amount of options and flexibility in terms of developing new therapies. However due to the controversy over using human embryos for this research, there is considerable pressure to find other sources of stem cells.
One solution to this problem has been learning to generate stem cells from normal adult cell types. In 2006 researchers Takahashi and Yamanaka successfully generated pluripotent stem cells from ordinary skin cells in mice. This Nobel-Prize-winning research removed a significant bottleneck in stem cell research and generated a flood of research into induced pluripotent stem cell lines.
Since then, efforts to reverse-engineer adult cells into induced pluripotent stem cells have utilized cells from a number of different organisms, including the horse. In addition to applying such research to humans, veterinary medicine also stands to benefit from equine stem cell research. Many horses suffer from musculoskeletal problems, and 50 percent of racing horses that suffer such problems never race again.
Though this research is not the first success story in generating pluripotent stem cells from the dermal fibroblasts of horses, there are several important advancements that were made. In previous studies the generation of these pluripotent stem cells has depended upon two growth factors: basic fibroblast growth factor (bFGF) and leukemia inhibitory factor (LIF). These growth factors are important chemical signals that tell cells to grow in size, increase in number, and differentiate into different kinds of cells. However in this study the stem cells produced only relied upon leukemia inhibitory factor, not the bFGF. This implies that these stem cells are “younger” (more naïve) than previous equine stem cells. This is an important step for scientists because it will theoretically give them more options for developing therapies and will also provide further insight into equine pluripotency.
Less than a decade after Takahashi and Yamanaka transformed the first adult skin cells into induced pluripotent stem cells, it is amazing to see how quickly stem cell research has advanced. Not only humans but perhaps in the near future horses too will see the benefits of personalized stem cell therapy.
By Sarah Takushi