Effect of bone marrow-derived mesenchymal stem cells and stem cell supernatant on equine corneal wound healing in vitro

BACKGROUND: We aimed to determine and compare the in vitro effects of autologous bone marrow-derived mesenchymal stem cells (BM-MSCs) and mesenchymal stem cell supernatant (MSC-Sp) on the wound healing capacity of equine corneal fibroblasts using a scratch assay. METHODS: Bone marrow aspirates and eyes were collected from normal, euthanized horses with subsequent isolation and culture of BM-MSCs and corneal stromal cells. Corneal stromal cells were culture-expanded in the culture well of transwell plates and then treated with an autologous BM-MSC suspension (dose: 2.5 × 10(5)/100 μL media with the BM-MSCs contained within the insert well), MSC-Sp solution, or naive culture media (control) for 72 h. A linear defect in confluent cell cultures was created (i.e., corneal scratch assay) to assess the cellular closure (“healing”) over time. Three representative areas of the scratch in each culture were photographed at each time point and the scratch area was quantitated using image analysis software (ImageJ). Media from the scratches were analyzed for various growth factors using human enzyme-linked immunosorbent assay (ELISA) kits that crossreact with the horse. RESULTS: There was a significant percentage decrease in the scratch area remaining in the BM-MSC and MSC-Sp groups compared to the control group. There was also a significant percentage decrease in the scratch area remaining in the BM-MSC group compared to the MSC-Sp group at 36 h post-scratch and all time points thereafter. The concentration of transforming growth factor (TGF)-β1 in the media was significantly higher in the BM-MSC group compared to the control group. CONCLUSIONS: The significant decrease in scratch area in equine corneal fibroblast cultures treated with autologous BM-MSCs compared to MSC-Sp or control treatments suggests that BM-MSCs may substantially improve corneal wound healing in horses. MSC-Sp may also improve corneal wound healing given the significant decrease in scratch area compared to control treatments, and would be an immediately available and cost-effective treatment option. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13287-017-0577-3) contains supplementary material, which is available to authorized users.