Effects of Mesenchymal Stem/Stromal Cells on Cultures of Corneal Epithelial Progenitor Cells With Ethanol Injury

PURPOSE. Mesenchymal stem/stromal cells (MSCs) facilitate the regeneration of injured tissue. Our group has previously shown that human MSCs (hMSCs) or hMSC-derived factors suppress excessive inflammatory response in the cornea following chemical injury in vivo. We here investigated direct effects of hMSC-derived factors on cultures of chemically injured human corneal epithelial progenitor cells (hCEP), independent of systemic anti-inflammatory effects that hMSCs have been shown to have in vivo. METHODS. We injured hCEP by incubation in 20% ethanol for 30 seconds, and cultured the cells in fresh medium or in medium derived from cultures of human dermal fibroblasts (hFbs), hMSCs, or TNF-alpha-activated hMSCs. After 24 hours, we evaluated the survival, proliferation, and apoptosis of the cells. RESULTS. The hMSC-conditioned medium enhanced survival and proliferation and inhibited apoptosis of chemically injured hCEP. In addition, the conditioned medium accelerated the wound healing of corneal epithelium in tissue cultures of rabbit corneas following injury. The effects of the hMSC-conditioned medium were increased by preincubating hMSCs with TNF-alpha The increased effectiveness of the medium from the preactivated hMSCs was in part explained by increased concentration of the multifunctional protein stanniocalcin-1 that inhibits apoptosis and promotes survival of cells. CONCLUSIONS. Together, the data account for beneficial effects of hMSCs on tissue-endogenous stem cells involving hCEP, and provide a basis for using MSCs or MSC-derived factors to treat diseases of the cornea and other tissues.