Abstract
Purpose :
The unfolded protein response (UPR) caused by endoplasmic reticulum stress (ER stress) is one of the important factors of developing Fuchs endothelial corneal dystrophy (FECD) pathogenesis. Our previous work showed the expression level of microRNA-29 (miR-29) was decreased in corneal endothelial cells derived from FECD patients. In this study, to analyze the role of miR-29b for ER stress triggered apoptosis in FECD, we evaluated expressions of UPR and apoptosis markers in immortalized FECD corneal endothelial cells (iFECD) and miR-29b overexpressed iFECD (iFECD+miR29b).
Methods :
Transfecting mimic miR-29b to iFECD, 50% confluent iFECD was cultured with mimic miR29b and RNAiMAX (Invitrogen) complex for 48 hours. The mRNA expression levels of UPR markers (BIP, PERK, ATF6, IRE-1, ATF4, XBP1, JNK, CHOP), pro-apoptotic markers (CytC, CASP9, CASP3, CASP7) and anti-apoptotic markers (BCL-2, BCL-XL) were evaluated with qPCR. Protein expression of BIP and ATF4 were assessed by Western blotting. Immortalized normal corneal endothelial cells (from donor cornea) were cultured as control samples.
Results :
Compared with iHCEC, miR29b expression in iFECD was 1.8 ± 1.2% and in iFECD+miR29b was 957.1 ± 441.7%. In iFECD, mRNA expression of BIP (molecular chaperone), PERK, ATF6 (ER stress-sensors) and BCL-XL (anti-apoptotic factor) were significantly higher than in iHCEC, but there were no significant difference in expression of these molecules at the protein level between iFECD and iHCEC.
Otherwise, in iFECD+miR29b, mRNA expression of CASP7 (pro-apoptotic factor) was significantly suppressed and that of BCL-2 (anti-apoptotic factor) was significantly increased compared with in iFECD.
Conclusions :
These findings suggest that overexpression of miR-29b may suppress endothelial cells apoptosis in FECD.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.