Equine mesenchymal stromal cells dual-primed with TGF-β1 and IL-1β or TNF-α improve epithelial healing in vitro

Mesenchymal stromal cells (MSCs) secrete paracrine factors that contribute to their ability to promote tissue healing and regeneration. Priming equine MSCs with cytokines like TGF-β is known to enhance expression of growth factors and extracellular matrix molecules, which may increase their potential for treating certain injuries including epithelial wounds. We hypothesized that dual priming equine MSCs with TGF-β1 plus the inflammatory cytokines IL-1β or TNF-α would further increase expression of paracrine factors relevant to epithelial healing and their therapeutic potential. We also compared paracrine factor expression from primed equine MSCs with primed human induced MSCs to understand if the results in equine cells may be directly translatable to human regenerative medicine. Priming equine MSCs did not affect the morphology or viability of the cells. Equine MSCs dual-primed with TGF-β1 + IL-1β or TGF-β1 + TNF-α had increased production of PGE2 and increased expression of AREG , and HBEGF . Conditioned media from both naïve and primed MSCs increased wound closure rates in an epithelial cell migration assay and dual-primed MSCs significantly increased the proliferation colonoids in a co-culture model. Priming human induced MSCs did not stimulate the same changes in paracrine factor expression seen in equine MSCs. Priming equine MSCs with TGF-β1 + IL-1β or TGF-β1 + TNF-α is a promising strategy for generating cells or conditioned media with the necessary growth factors and cytokines to promote epithelial healing.