Xeno- and Feeder-Free Differentiation of Human iPSCs to Trabecular Meshwork-Like Cells by Recombinant Cytokines

PURPOSE: Stem cell-based therapy has the potential to become one approach to regenerate the damaged trabecular meshwork (TM) in glaucoma. Co-culture of induced pluripotent stem cells (iPSCs) with human TM cells has been a successful approach to generate autologous TM resembling cells. However, the differentiated cells generated using this approach are still problematic for clinical usage. This study aimed to develop a clinically applicable strategy for generating TM-like cells from iPSCs. METHODS: Highly expressed receptors during iPSC differentiation were identified by AutoSOME, Gene Ontology, and reverse transcription polymerase chain reaction (RT-PCR) analysis. The recombinant cytokines that bind to these receptors were used to generate a new differentiation protocol. The resultant TM-like cells were characterized morphologically, immunohistochemically, and transcriptionally. RESULTS: We first determined two stages of iPSC differentiation and identified highly expressed receptors associated with the differentiation at each stage. The expression of these receptors was further confirmed by RT-PCR analysis. Exposure to the recombinant cytokines that bind to these receptors, including transforming growth factor beta 1, nerve growth factor beta, erythropoietin, prostaglandin F2 alpha, and epidermal growth factor, can efficiently differentiate iPSCs into TM-like cells, which express TM biomarkers and can form dexamethasone-inducible CLANs. CONCLUSIONS: We successfully generated a xeno- and feeder-free differentiation protocol with recombinant cytokines to generate the TM progenitor and TM-like cells from human iPSCs. TRANSLATIONAL RELEVANCE: The new approach minimizes the risks from contamination and also improves the differentiation efficiency and consistency, which are particularly crucial for clinical use of stem cells in glaucoma treatment.