Korean J Ophthalmol.  2016 Dec;30(6):468-478. 10.3341/kjo.2016.30.6.468.

Tunicamycin-induced Endoplasmic Reticulum Stress Upregulates the Expression of Pentraxin 3 in Human Retinal Pigment Epithelial Cells

• Hwang N
• Kwon MY
• Cha JB
• Chung SW
• Woo JM

• KMID: 2374005
• DOI: http://doi.org/10.3341/kjo.2016.30.6.468

Abstract

PURPOSE
To investigate the production of long pentraxin 3 (PTX3) in response to tunicamycin-induced endoplasmic reticulum (ER) stress and its role in ER stress-associated cell death, PTX3 expression was evaluated in the human retinal pigment epithelial cell line, ARPE-19.
METHODS
PTX3 production in ARPE-19 cells was analyzed in the absence or presence of tunicamycin treatment by enzyme-linked immunosorbent assay. PTX3 protein and mRNA levels were estimated using western blot analysis and real-time reverse transcription-polymerase chain reaction, respectively. Protein and mRNA levels of CCAAT-enhancer-binding protein homologous protein (CHOP) and ARPE-19 cell viability were measured in the presence of tunicamycin-induced ER stress in control or PTX3 small hairpin RNA (shRNA)-transfected ARPE-19 cells.
RESULTS
The protein and mRNA levels of PTX3 were found to be significantly increased by tunicamycin treatment. PTX3 production was significantly decreased in inositol-requiring enzyme 1α shRNA-transfected ARPE-19 cells compared to control shRNA-transfected cells. Furthermore, pretreatment with the NF-κB inhibitor abolished tunicamycin-induced PTX3 production. Decreased cell viability and prolonged protein and mRNA expression of CHOP were observed under tunicamycin-induced ER stress in PTX3 shRNA transfected ARPE-19 cells.
CONCLUSIONS
These results suggest that PTX3 production increased in the presence of tunicamycin-induced ER stress. Therefore, PTX3 could be an important protector of ER stress-induced cell death in human retinal pigment epithelial cells. Inositol-requiring enzyme 1α and the NF-κB signaling pathway may serve as potential targets for regulation of PTX3 expression in the retina. Therefore, their role in PTX3 expression needs to be further investigated.

Keyword

Endoplasmic reticulum stress; Human retinal pigment epithelial cells; Inositol-requiring enzyme 1α; Pentraxin 3

MeSH Terms

Anti-Bacterial Agents/pharmacology
Apoptosis
Blotting, Western
C-Reactive Protein/biosynthesis/*genetics
Cells, Cultured
Endoplasmic Reticulum Stress/*drug effects/genetics
Enzyme-Linked Immunosorbent Assay
*Gene Expression Regulation
Humans
Polymerase Chain Reaction
RNA, Messenger/*genetics
Retinal Pigment Epithelium/*metabolism/pathology
Serum Amyloid P-Component/biosynthesis/*genetics
Tunicamycin/*pharmacology
Anti-Bacterial Agents
C-Reactive Protein
RNA, Messenger
Serum Amyloid P-Component
Tunicamycin