Apoptotic stimuli activated Rho/ROCK/MLC phosphorylation in the corneal endothelium, and subsequent actomyosin contraction induced apoptosis by loss of cell adhesion. ROCK inhibition suppressed MLC phosphorylation and subsequent cell death, and it counteracted the loss of cell adhesion by activating the focal adhesion complex.

Transparency of the cornea is essential for vision and is maintained by the corneal endothelium. Consequently, corneal endothelial decompensation arising from irreversible damage to the corneal endothelium causes severe vision impairment. Until recently, transplantation of donor corneas was the only therapeutic choice for treatment of endothelial decompensation. In 2013, we initiated clinical research into cell-based therapy involving injection of a suspension of cultured human corneal endothelial cells (HCECs), in combination with Rho kinase inhibitor, into the anterior chamber. The aim of the present study was to establish a protocol for cryopreservation of HCECs to allow large-scale commercial manufacturing of these cells. This study focused on the effects of various cryopreservation reagents on HCEC viability. Screening of several commercially available cryopreservation reagents identified Bambanker hRM as an effective agent that maintained a cell viability of 89.4% after 14 days of cryopreservation, equivalent to the cell viability of 89.2% for non-cryopreserved control cells. The use of Bambanker hRM and HCECs at a similar grade to that used clinically for cell based therapy (passage 3–5 and a cell density higher than 2000 cells/mm 2 ) gave a similar cell density for cryopreserved HCECs to that of non-preserved control HCECs after 28 days of cultivation (2099 cells/mm 2 and 2111 cells/mm 2 , respectively). HCECs preserved using Bambanker hRM grew in a similar fashion to non-preserved control HCECs and formed a monolayer sheet-like structure. Cryopreservation of HCECs has multiple advantages including the ability to accumulate stocks of master cells, to transport HCEC stocks, and to manufacture HCECs on demand for use in cell-based treatment of endothelial decompensation.

We believe this to be the first report of conservation of the nectin-afadin system in the corneal endothelium and its involvement in the formation of adherens junctions. N-cadherin, as a member of the cadherin family, is also essential for the formation and maintenance of cell-cell adhesion mediated by nectins and tight junctions in the corneal endothelium.

Purpose: To develop software to evaluate the fibroblastic morphological changes in cultured human corneal endothelial cells (HCECs) as a quality control measure for use in tissue engineering therapy. Methods: Software was designed to recognize cell borders, to approximate cell shape as an ellipse, and to calculate the aspect ratio of the ellipse as an indicator of severity of the fibroblastic morphological change. Using the designed software, 60 phase contrast images of polygonal HCECs and 60 phase contrast images of fibroblastic HCECs were analyzed. The correlations of the aspect ratio and other parameters (cell density, percentage of cells surrounded by 6 cells, and coefficient of variation) were evaluated. Results: Cell shapes were recognized based on phase contrast images and were approximated as ellipses by software. The average aspect ratio was significantly higher (34.9% ± 6.1%) in fibroblastic HCECs than in polygonal HCECs (24.4% ± 2.3%) (P < 0.01). The aspect ratio showed a correlation with cell density, with the percentage of cells surrounded by 6 neighboring cells, and with the coefficient of variation (Pearson correlation coefficients, −0.84, −0.38, and 0.66, respectively). Conclusions: We propose that fibroblastic alteration of HCECs can be evaluated by the cell morphology based on the aspect ratio. Software developed in this study, which can analyze the frequency and severity of fibroblastic alteration, will be useful for nondestructive assessment of cells destined for use in cell-based therapy for corneal endothelial decompensation.