The condition medium of mesenchymal stem cells promotes proliferation, adhesion and neuronal differentiation of retinal progenitor cells.

Retinal progenitor cell is a promising candidate in the treatment of retinal pigmentosa diseases. The limiting factors of stem cell transplantation are the proliferation and differentiation capacities of hRPCs, which may be governed by culture conditions. Previous studies have proved that the secretome of human Umbilical Cord Mesenchymal stem cells (hUCMSCs) and human Adipose derived stem cells (hADSCs), including more active cytokines and neurotrophic factors, have the paracrine potential of enhancing proliferation and differentiation in several cell types. The aim of this study was to investigate whether hRPCs could effectively proliferate, adhere and differentiate towards specific retinal cell types by treating with the condition medium (CM) of hUCMSCs (hUCMSCCM) or hADSCs (hADSCCM). Here, we show that hUCMSCCM or hADSCCM enhances the proliferation rate of the S and G2 phase cells, with an upregulation of Ki67 expression. Moreover, the upregulation expression of NF, Recoverin and Rhodopsin indicates that specialized retinal cells including ganglion cells and photoreceptors are favored over hRPCs differentiation due to hUCMSCCM or hADSCCM. Under FBS induced differentiation conditions, hRPCs treated with hUCMSCCM or hADSCCM increase the expression of retinal neuron and photoreceptor specific markers. These results suggest that hUCMSCCM and hADSCCM can stimulate the hRPC proliferation, promote its adherence and support hRPC neuronal and photoreceptor differentiation. These findings may provide a new strategy to improve the viability of hRPCs and photoreceptor differentiation capacities.