LY2109761, Transforming Growth Factor β Receptor Type I and Type II Dual Inhibitor, is a Novel Approach to Suppress Endothelial Mesenchymal Transformation in Human Corneal Endothelial Cells.

BACKGROUND/AIMS: Preventing undesirable endothelial-mesenchymal transformation (EnMT) with repetitious in vitro expansion of human corneal endothelial cells (CECs) is a pivotal issue in cornea regeneration. Previous studies have shown that inhibition of the TGF-β pathway reduces epithelial-mesenchymal transformation. However, its potential role in EnMT remains poorly understood. As such, the effect of LY2109761, a novel TGF-β receptor type I and type II dual inhibitor, was investigated on EnMT.

METHODS

CECs cultured with various concentrations of LY2109761 were evaluated for their growth rate and phenotype. Additionally, the expression of functional markers (sodium-potassium pump Na+/K+-ATPase and the tight junction protein ZO-1) and mesenchymal markers (CD73, fibronectin, and vimentin) was detected using immunostaining and western blot. The mRNA expressions were also assayed by real-time polymerase chain reaction analysis.

RESULTS

At a 1 μM concentration, LY2109761 did not influence the proliferation of CECs and subsequent experiments were therefore performed using this concentration. Furthermore, CECs cultured in the presence of 1 μM LY2109761 maintained their ability to grow as a monolayer of hexagonal-shaped cells. The expression of functional markers increased in LY2109761-treated CECs, while the expression of mesenchymal markers decreased (both in protein and mRNA levels).

CONCLUSION

Inhibition of TGF-β receptor type I and type II by LY2109761 maintained the phenotype of CECs and inhibited the EnMT process. These results indicate the possible continuous in vitro expansion of CECs with normal function.