Abstract
Purpose :
Cells of the retinal pigment epithelium (RPE) play critical roles in ocular development and visual function. Mature RPE cells normally maintain in a quiescent state and form a stable monolayer in vivo, but can be re-entry into cell cycle under disease states, such as PVR (proliferative vitreoretinopathy). The molecular mechanisms of regulating RPE cell proliferation have not been fully understood, the research purpose of this study is to identify the novel Long noncoding RNA (LncRNA) that involves into RPE cell proliferative regulation and to elucidate its underlying molecular mechanism.
Methods :
RNA-seq was used to analyze the LncRNA expression profiling between the mature RPE cells in vivo and cultured primary RPE cells in mice. RT-PCR was used to evaluate the expression of LncRNA NEAT1 in RPE cells. Cell proliferative state was carried out by cell counting, cell cycle analysis, and Ki67 immunofluorescence in ARPE-19 and D407 cells after the knockdown of NEAT1 by specific siRNAs. The expression levels of cell proliferation-related proteins were perfomed by Western blotting. The interactions between NEAT1 and microRNAs were pridicted by starBase and proved by luciferase reporter assay. miR-34a inhibitor was used to rescue the proliferation of si-NEAT1 transfected RPE cells.
Results :
LncRNA NEAT1 was expressesed in RPE cells in vivo, while its expression was increased in the high proliferaive RPE cells. Knockdown of NEAT1 in RPE cells inhibited the cell proliferation and down regulated the expression of c-Met, E2F1, and p-RB. NEAT1 acted through competitively binding with miR-34a to inhibit its functional roles, such as targeting c-Met in regulating RPE cell proliferation. Co-transfected si-NEAT1 with miR-34a inhibitor could partial rescue RPE cell proliferation.
Conclusions :
These results suggest that LncRNA NEAT1 acts as a novel RPE cell proliferative regulator through the axis of NEAT1-miR-34a-c-Met. Our findings provide molecular insights into the regulation of RPE cell proliferation and may help us understand the underlying mechanisms of RPE abnormal proliferation-aassociated diseases.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.