Mesenchymal stem cells (MSC) are multipotent stem cells that exhibit unique regenerative properties: (1) they are able to divide at a high rate but also (2) to differentiate into different specialized cell types and (3) to secrete various bioactive factors that both promote the recovery of damaged tissues and have an anti-inflammatory effect. Currently, MSC are used in both human and veterinary medicine for a wide range of therapies, ranging from treatments for tendon injuries and osteoarthritis to cardiological and neurological disorders. To develop new MSC therapies, representative in vitro models are needed before proceeding to in vivo clinical studies. Traditionally, in vitro models are used for this purpose, in which certain lesions are induced in rodents. In recent years, in vitro models in large domestic animals (such as horses) have become increasingly important because both the structure and function of the tissues are much more similar to those of humans, and also because similar conditions occur naturally in these domestic animals. However, such in vitro models are only representative if all tissue structures are present, i.e. not only the tissue-specific cells but also the blood flow and innervation. Mimicking the latter tissues in the lab is still a major challenge. Once such in vitro models have been developed, a platform becomes available to screen new drugs, allowing the number of laboratory animals to be drastically reduced.

In this project, the research group in Flanders will evaluate the neurogenic differentiation capacity of equine MSC and subsequently apply this in their in vitro tendon injury model. This protocol will be used by the research group from Québec to differentiate human MSC neurogenically and then incorporate them into their human arterial blood vessel model. By working cross-species in two different in vitro models, we will gain important insights into realizing innervation in vitro.