Effects of bone marrow mesenchymal stem cells on cell proliferation and growth factor expression of limbal epithelial cells in vitro.

Mesenchymal stem cells (MSCs) can play an active role in there construction of the ocular surface; however, the mechanisms by which the implanted MSCs exert their effects remain elusive. In the present study, we investigated the influences of MSCs on cell proliferation and growth factor expression of corneal limbal epithelial cells (LECs) in vitro. Rat LECs were either cocultured with rat MSCs or cultured in rat MSC condition edmedium. The harvested LECs were subjected to light microscopy, MTT assay, bromodeoxyuridine (BrdU)staining, flow cytometry and real-time quantitative RT-PCR analysis, respectively. Light microscopy showed that coculturing of LECs with MSCs significantly increased the proliferation of LECs. The MTT assay showed that MSC-conditioned medium significantly increased the cell viability of LECs compared to those incubated with plain medium. BrdU immunostaining and flow-cytometric analysis of the cell cycle showed that the cell proliferation rate of LECs cocultured with MSCs was significantly higher than that of LECs cultured alone. Real-time quantitative RT-PCR analysis showed that expression of epidermal growth factor in LECs cocultured with MSCs was significantly higher than that in LECs cultured alone. However, expression of basic fibroblast growth factor showed no difference under the two culture conditions. These results indicate that MSCs promote the survival and proliferation of LECs, and these effects may be mediated ina paracrine manner.