New research from the Royal Veterinary College (RVC) has revealed a fundamental difference in how the endothelial cells react in horses compared to humans. Regulating the factors that influence endothelial cell function is sometimes used to treat diseases such as cancer in humans, so the findings pave the way for further research in both horses and humans.
Endothelial cells are responsible for the formation of new blood vessels, such as after exercise or injury. This process of forming new blood vessels is called angiogenesis. Little is known about angiogenesis in horses despite the important part it plays in many equine diseases and recovery from injury. There is also interest in the use of the horse as a large animal model for human diseases. This research was therefore conducted to improve understanding of endothelial cell function in horses.
Conducting the first-ever study to optimise methods for the isolation, growth and purification of equine endothelial cells, the RVC research team studied equine endothelial cells in vitro. They examined factors related to the equine cells’ ability to form new blood vessels. Specific chemicals in the body stimulate endothelial cells to start the process of angiogenesis. The most studied growth factor responsible for this process in human cells is vascular endothelial growth factor A (VEGF-A), making it a focus of this research.
The findings revealed there was a difference in the function between equine and human endothelial cells. They found that VEGF-A had far less of an effect on the cells of horses than those of humans. Instead, equine endothelial cells respond much more strongly to a different growth factor known as fibroblast growth factor two (FGF2).
This difference in function between equine and human cells has never been identified before and is of great interest as to why horse cells are affected differently. Regulating VEGF-A is sometimes used as a treatment for cancer in humans, so given that equine endothelial cells do not respond to VEGF-A in the same way as human cells could be a useful trait to investigate. Further research is therefore needed to build on these outcomes and shed light on how this research can be of the greatest benefit when developing treatments for disease in horses and humans.
The RVC research team comprised Dr Elizabeth Finding, a vet, equine internal medicine specialist, and lecturer in basic sciences; Dr Ashton Faulkner, a lecturer in biomedical sciences; Miss Lilly Nash, PhD student; and Professor Caroline Wheeler-Jones, a Professor of vascular cell biology. Miss Misha Lee, an undergraduate BSc student at the RVC, also contributed to the project, providing a real-world research opportunity at the leading institution.
Dr Elizabeth Finding, lecturer in basic sciences and lead author of the paper, said:
“Endothelial cells are crucial to all body systems and the fact that we have known so little about them in the horse up to this stage has limited our ability to study many aspects of equine health and disease.
“Our methods can now be used by all researchers interested in the topic to further their work. I am excited by the possibility that the differences we have found between equine and human endothelial cells may be useful for studying human diseases.”
This research was funded by the Horserace Betting Levy Board.
