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Transforming growth factor β (Tgf-β), a pleiotropic cytokine, can enhance DNA repair in various cells, including cancer cells and neurons. The noncoding regulatory system plays an important role in Tgf-β-mediated biological activities, whereas few studies have explored its role in DNA damage and repair. In this study, we suggested that Tgf-β improved while its inhibitor LSKL impaired DNA repair and cell viability in UV-irradiated 661W cells. Moreover, RNA-seq was carried out, and a total of 106 differentially expressed (DE)-mRNAs and 7 DE-lncRNAs were identified between UV/LSKL and UV/ctrl 661W cells. Gene ontology and Reactome analysis confirmed that the DE-mRNAs were enriched in multiple DNA damaged- and repair-related biological functions and pathways. We then constructed a ceRNA network that included 3 lncRNAs, 19 miRNAs, and 29 mRNAs with a bioinformatics prediction. Through RT-qPCR and further functional verification, 2 Tgf-β-mediated ceRNA axes (Gm20559-miR-361-5p-Oas2/Gbp7) were further identified. Gm20559 knockout or miR-361-5p mimics markedly impaired DNA repair and cell viability in UV-irradiated 661W cells, which confirms the bioinformatics results. In summary, this study revealed that Tgf-β could reduce DNA damage in 661W cells, provided a Tgf-β-associated ceRNA network for DNA damage and repair, and suggested that the molecular signatures may be useful candidates as targets of treatment for photoreceptor pathology.

Purpose Chemokine receptor 4 (CXCR4) plays an essential role in the early stage of corneal neovascularization (CNV), but the underlying key molecular mechanism has yet to be addressed. This study aimed to explore the new molecular mechanism of CXCR4 in CNV and the related pathological events. Methods CXCR4 was assayed by immunofluorescence or Western blotting. The function of the supernatant from hypoxia-treated human corneal epithelial cells (HCE-T) cells was examined by culturing with human umbilical vein endothelial cells. MicroRNA sequencing was used to detect the downstream microRNAs upon CXCR4 knockdown and analyzed by preliminary bioinformatics. The proangiogenic functions and downstream target genes of microRNA were investigated by gene interference and luciferase assay. An alkali-burned murine model was introduced to examine the function and mechanism of miR-1910-5p in vivo. Results High CXCR4 expression was confirmed in corneal tissues of patients with CNV and hypoxic HCE-T cells. The supernatant from hypoxia-treated HCE-T cells is involved in the CXCR4-mediated angiogenesis of human umbilical vein endothelial cells. Notably, miR-1910-5p was demonstrated to be at a high level in wild-type HCE-T cells and its supernatant, and in CNV patient tears. The proangiogenic functions of miR-1910-5p were demonstrated with the assays of cell migration, tube formation, and aortic ring. Moreover, miR-1910-5p significantly inhibited multimerin-2 expression by targeting its 3ʹ untranslated region and caused significant extracellular junctional defects in human umbilical vein endothelial cells. MiR-1910-5p antagomir could significantly increase multimerin-2 level and decrease vascular leakage, and ultimately inhibit CNV in a murine model. Conclusions Our results revealed a novel CXCR4-mediated mechanism and proved that targeting the miR-1910-5p/multimerin-2 pathway could be a promising therapeutic target for CNV.