Differentiation of Bone Marrow Mesenchymal Stem Cells into Retinal Ganglion-like Cells Induced by Math5

We explored the appropriate inducing conditions needed to facilitate the differentiation of bone marrow mesenchymal stem cells(BMSCs) into retinal ganglion cells(RGCs). Math5, a pro-neural basic helix-loop-helix(bHLH) gene, was constructed in an adenoviral vector and then infected into the 3rd passage BMSCs. An inverted fluorescence microscope was used to observe the morphological changes of the infected cells. The expressions of Math5, the neuromarkers neuron-specific enolase(NSE), neurofilament(NF), Thy1.1, and the RGC-related genes GAP-43 and Brn3b were examined by Western blot and reverse transcription-polymerase chain reaction(RT-PCR). The results show that cells infected with Math5 adenoviral vector were able to stably express Math5 and presented with a typical morphology of RGCs. Moreover, these cells expressed NSE, NF, Thy1.1, and GAP-43. Under the synergistic induction conditions of retinal conditioned, differentiation medium in combination with epidermal growth factor(EGF) and basic fibroblast growth factor(BFGF), BMSCs infected with Math5 adenoviral vector had a more typical morphology of RGCs, with a greater number of longer axons that connected with each other and formed a net. In addition, the number of NF positive cells was higher, the expression of Brn3b was detected, and the expressions of NSE, NF, and GAP-43 were significantly up-regulated compared to those of them in the control. These results indicate that BMSCs infected with Math5 are able to differentiate into retinal ganglion-like cells. Moreover, Math5 is a stronger activator of the downstream gene Brn3b than the cytokine, which suggests that it is possible to regulate the survival and axon path determination of these differentiated cells.