DIFFERENTIATION OF EQUINE MESENCHYMAL STROMAL CELLS INTO CELLS OF NEURAL LINEAGE AND THEIR APPLICATION INTO A NOVEL MODEL FOR ACUTE PERIPHERAL NERVE INJURY IN THE HORSE

Studies have shown that mesenchymal stromal cells (MSCs) are able to differentiate into extra-mesodermal lineages, including neurons. Positive outcomes were obtained after transplantation of neurally-induced MSCs in rats, rabbits and guinea pigs after nerve injury, but the effect of these cells is unknown in horses. Our objective was to test the ability of equine mesenchymal stromal cells to differentiate into cells of neuronal lineage, and to assess differences, if any, in morphology and protein expression. Additionally, we wanted to investigate if horse age and cell passage number contributed to the ability to achieve neural differentiation.

The first part of this research focuses on assessing the potential of equine bone marrow-derived mesenchymal stromal cells to undergo differentiation into cells of neural lineage cells after prior demonstration of their stemness. It describes the optimization of in vitro conditions to induce neural differentiation of equine MSCs and the use of neural markers in equine MSCs, which has not been previously reported.

Subsequent research focuses on further commitment of these neural cells into Schwann-like cells for possible transplantation into an acute peripheral nerve injury model in horses. After optimizing the laboratory conditions to induce Schwann cell differentiation of equine MSCs, their detachment from the tissue culture flasks resulted in poor viability. Therefore, undifferentiated MSCs were transplanted in the surrounding fascia after transecting the central portion of the anastomotic branch (ramus communicans) of the lateral and medial palmar nerves of the fore limbs in healthy horses. Approximately 45 days after the lesion was created, the whole nerve was removed for histological analyses.