AUTHOR=Wang Yuexia , Wang Yue , Wang Xue , Ma Yuan , Li Zhaojin , Di Yu 

TITLE=LncRNA TUG1 Promotes Apoptosis, Invasion, and Angiogenesis of Retinal Endothelial Cells in Retinopathy of Prematurity via MiR-145-5p

JOURNAL=Frontiers in Medicine

VOLUME=9

YEAR=2022

URL=https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2022.803214

DOI=10.3389/fmed.2022.803214

ISSN=2296-858X

ABSTRACT=<sec><title>Purpose</title><p>Retinopathy of prematurity (ROP) is a common retinal vascular disease in premature neonates. In recent years, there is increasing evidence that the long non-coding RNA taurine upregulated gene 1 (<italic>TUG1</italic>) plays a regulatory role in vascular diseases, suggesting a potential role for <italic>TUG1</italic> in vascular endothelial cells. We hypothesized that <italic>TUG1</italic> may be associated with ROP. Our aim, therefore, was to explore the biological functions of <italic>TUG1</italic> in aberrant retinal development.</p></sec><sec><title>Methods</title><p>We used the mouse oxygen-induced retinopathy (OIR) model to simulate the pathological changes of retinal in ROP. Quantitative real-time polymerase chain reaction was used to detect the expression of <italic>TUG1</italic>, miR-145-5p and cellular communication network factor 1 (CCN1). Human retinal endothelial cells (HRECs) were treated with CoCl<sub>2</sub> to mimic hypoxia conditions. Cellular functional changes were observed after transfection with RNA interference (RNAi)-TUG1 and miR-145-5p mimics. The apoptosis of HRECs was detected by flow cytometry, the migration ability was detected by wound healing and transwell migration assays, and the ability of angiogenesis was detected by tube formation assay. The potential binding sites between <italic>TUG1</italic>, miR-145-5p, and CCN1 were verified by dual-luciferase reporter assays. The degree of retinopathy was evaluated by staining retinal sections with hematoxylin and eosin, and the expression of CCN1, HIF-1α, VEGF, caspase-3, Bcl-2, IL-1β, and TNF-α protein was analyzed by Western blotting and immunohistochemistry.</p></sec><sec><title>Results</title><p>In the retina tissue of OIR mice, <italic>TUG1</italic>, miR-145-5p, and CCN1 were differentially expressed. Knocking down <italic>TUG1</italic> attenuated apoptosis, migration, and angiogenesis induced by hypoxia on HRECs, as did miR-145-5p overexpression. Results from reporter assays indicate direct interactions between <italic>TUG1</italic>, miR-145-5p, and CCN1. Intravitreal injection of miR-145-5p mimics reduced the degree of retinopathy.</p></sec><sec><title>Conclusion</title><p><italic>TUG1</italic> acts as a molecular sponge of miR-145-5p to regulate CCN1 expression and thus regulate the development of retinal neovascularization. This regulatory mechanism may provide a new theoretical basis for the prevention and treatment of ROP.</p></sec>