Methodological study of directed differentiation of pluripotent stem cells into corneal endothelial cells.

Background: Corneal transplantation is the most effective clinical treatment for irreversible corneal endothelial decompensation. However, while visual rehabilitation can be achieved by corneal transplantation, transplant rejection, poor postoperative visual acuity, and lack of suitable donor tissue are currently the greatest obstacles to corneal transplantation. As a result, endothelial cell-based therapy has emerged as an alternative to corneal transplantation treatment. Human induced pluripotent stem cells (hiPSCs) were induced to differentiate into human corneal endothelial cell (hCEC)-like cells in our study, which aimed to provide an experimental basis for studying the clinical translation and application of induced PSC (iPSC) to corneal endothelial cell (CEC) differentiation.

Methods: A two-step method to convert hiPSCs into hCEC-like cells was applied in the study. First, the transforming growth factor beta (TGF-β) and Wnt signaling pathways were regulated by adding SB4315542 and CHIR99021, and hiPSCs were induced to differentiate into neural crest cells (NCCs) by a chemically defined and serum-free induction method. Subsequently, NCCs were induced to differentiate into hCEC-like cells by adding B27, platelet-derived growth factor (PDGF)-BB, and XAV939 (Wnt pathway inhibitor) to CEC culture medium.

Results: IPSCs were directionally differentiated into NCCs. During the process of differentiation, iPSCs gradually lost the monoclonal morphology of PSCs. Moreover, β-catenin and SRY-related HMG-box gene 10 () proteins were immunohistochemically expressed on the 7th day of differentiation. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) results demonstrated that the cells expressed , nerve growth factor receptor (), human natural killer-1 (), and , indicating that they were successfully directionally differentiated from iPSCs to NCCs. After 5-7 days of differentiation, the cells demonstrated a hexagonal morphology of monolayer tight junctions. Immunofluorescence results demonstrated that the cells expressed CEC indicator zonula occludens-1 () protein. QRT-PCR results demonstrated that the cells expressed collagen type IV alpha 1 (), , and , which indicated that they were successfully directionally differentiated from NCC to CEC.

Conclusions: Our study successfully provided a simple and efficient method with clear chemical composition and serum-free media to directionally differentiate hiPSCs into hCEC-like cells, thereby advancing the results of previous studies on directional transformation into epithelial cells.