Abstract
Purpose :
We previously reported that epithelial-mesenchymal transition (EMT)-related genes are engaged in the excessive production of extracellular matrix (ECM) proteins through the transforming growth factor (TGF)-β signaling pathway in Fuchs endothelial corneal dystrophy (FECD). It has recently been reported that TGF-β increases a disintegrin and metalloproteinase 10 (ADAM10), and induces fibrosis of lung and skin fibroblasts (Lagares D, et al., Nature. 2017). The purpose of this present study was to investigate the involvement of ADAM10 in the ECM production of FECD.
Methods :
Corneal endothelium was obtained from FECD patients and non-FECD donor corneas. The expression of ADAM10 mRNA was determined by quantitative polymerase chain reaction (qPCR). Corneal endothelial cells obtained from the FECD-patient endothelium were cultured and immortalized as an FECD cell model (iFECD), and were then treated with ADAM10 inhibitor (GI254023X) or knockdown ADAM10 siRNA. Their effect on EMT-related molecules and fibronectin was the evaluated by qPCR and western blotting. In addition, the effect of GI254023X or ADAM10 siRNA on TGF-β2-mediated fibroblastic change was evaluated by phase contrast microscopy, and the effect of TGF-β2 on ADAM10, EMT-related molecules, and FN1 was evaluated by qPCR.
Results :
qPCR showed that ADAM10 expression level normalized by GAPDH was significantly higher in the corneal endothelium of FECD patients than in that of the non-FECD control (1.66±0.07 and 0.78±0.03, respectively) (p<0.01). In iFECD, GI254023X and knockdown of ADAM10 significantly downregulated the expression level of SNAI1, SNAI2, FN1, but not ZEB1 and TWIST1 (p<0.01). Consistently, western blotting showed that both GI254023X and knockdown of ADAM10 suppressed Snail1 and fibronectin at protein levels. Moreover, phase-contrast images showed that TGF-β2 induced fibroblastic change in iFECD, yet GI254023X and knockdown of ADAM10 counteracted TGF-β2-mediated morphological change. TGF-β2 increased the ADAM10 expression by 1.6 fold in iFECD (p<0.01), while SNAI1, SNAI2, and FN1 were also increased.
Conclusions :
Our findings showed that ADAM10 is upregulated in the corneal endothelium of FECD patients, and that it is involved in the excessive production of ECM, probably via the TGF-β-mediated activation of EMT-related molecules.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.