Help us fight disease and injury in animals

Introduction

Stem cells have the ability to self-renew to generate more stem cells and also to turn into other types of cells. Broadly, stem cells can be classified into two groups; multipotent stem cells and pluripotent stem cells. Multipotent or “adult” stem cells exist in many different tissues and can only turn into a limited number of cell types. In contrast pluripotent or “embryonic” stem cells exist at the very earliest stages of development and can turn into every cell type of the body. Stem cells therefore have the potential to be used therapeutically to aid tissue regeneration following injury or disease.

We are carrying out research to use stem cells in veterinary medicine. To date our research has focussed on the horse and we have derived pluripotent stem cells from horse embryos and multipotent stem cells from adult horse tissues.

The pluripotent horse embryo-derived stem cells (ES cells) can be grown indefinitely in the laboratory, express markers associated with pluripotency and can turn numerous types of cells in the laboratory. These include nerve cells, connective tissue cells and many others. The main difference between the ES cells we have isolated from horses and ES cells isolated from humans is that the horse ES cells have not formed detectable tumours in experimental tests. We hope to exploit this fact in order to use the cells therapeutically.

We have also derived multipotent mesenchymal stem cells (MS cells) from the bone marrow and fat tissue of adult horses and the umbilical cord blood of new-born foals. MS cells can only turn into connective tissue cell types such as bone, cartilage and tendon.

MS cells are already being used clinically to try to treat tendon repair in horses. Tendon injuries occur commonly in racing and sport horses and because the injuries heal through the formation of scar tissue instead of normal tendon tissue they are associated with a high rate of re-injury when the horse returns to normal work. Stem cells may help to bring about normal tendon regeneration and therefore reduce the frequency of re-injury. Clinical and experimental results with MS cells are promising but it is not yet a proven treatment and further research needs to be undertaken to understand how the cells work.