UMSC-derived exosomes promote retinal ganglion cells survival in a rat model of optic nerve crush

Traumatic optic neuropathy or glaucoma lead to retinal ganglion cells loss and cause blindness, and there is no effective therapy strategy by far. Mesenchymal cells from the Wharton's jelly of the umbilical cord (umbilical cord mesenchymal stem cells, UMSCs) and UMSC-derived exosomes (UMSC-Exos) are promising candidates for allogeneic therapy in regenerative medicine, but their effort on optic nerve injury and the underlying mechanism remains undefined. In the present study, we investigated the functions of UMSC-Exos in a rat optic nerve crush (ONC) model. After three times of treatments with an interval of one week, we found that the UMSC-Exos significantly promoted Bm3a(+) retinal ganglion cells (RGCs) survival in retinal ganglion cell layer compared with PBS controls. UMSC-Exos also significantly promoted GFAP(+) glia cells activation in retina and optic nerve. However, no increase of GAP43(+) axon counts in the optic nerve was found after UMSC-Exos treatment. Thus, our results demonstrate that UMSC-derived exosomes may play a role in neuroprotection by promoting the RGCs survival and glia cells activation but not the axon regeneration.