Cell-Injection Therapy using Cultivated Corneal Endothelial Cells Combined with a ROCK Inhibitor in a Primate Model

Abstract

Purpose: : To investigate the feasibility of corneal endothelial reconstruction by a cell-injection therapy using cultivated monkey corneal endothelial cells (MCECs) combined with Rho-associated protein kinase (ROCK) inhibitor Y-27632 in a primate model.

Methods: : Monkey corneal endothelium was intensively scraped off up to the peripheral area to make a corneal endothelial dysfunction model. The Descemet’s membrane was left intact. A 2x10⁵ amount of cultivated MCECs suspended in Dulbecco’s modified eagle medium (DMEM) with 100µM Y-27632 was injected into the anterior chamber of 2 eyes of 2 animals (Y-27632(+) group). The same procedure was performed without using Y-27632 in 2 eyes of 2 animals (Y-27632(-) group). The eye of each animal was then kept in the face-down position for 3 hrs. In the control group, endothelial cells were scraped and MCECs were not injected (2 eyes) and cell-injection was performed with the eye left in the face-up position (1 eye). Slit-lamp examinations and corneal thickness- and intraocular pressure measurements were performed for up to 3 months, followed by immunohistochemical analysis.

Results: : Four eyes which had cell-injection followed by the face-down position recovered a clear cornea and retained that clarity up to 3 months. Corneal thickness was much thinner in those 4 eyes compared to the 3 eyes in the control group which demonstrated bullous keratopathy. Three months after surgery, the homogeneous monolayer of polygonal cells expressing ZO-1 and Na⁺K⁺ATPase was reconstructed in the Y-27632(+) group and the corneal endothelial cell density was much higher in the Y-27632(+) group compared to the Y-27632(-) group (2208 and 789 cells/mm², respectively). No eye showed intraocular pressure elevation.

Conclusions: : Corneal endothelium was well reconstructed by the cell-injection therapy using cultivated MCECs combined with Y-27632 in a primate model. We speculate that cell-injection therapy using Y-27632 might be advantageous, as it enables cultivated corneal endothelial cell transplantation without a carrier and with a less invasive procedure.

Keywords: cornea: endothelium • transplantation