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Shi X, Won M, Tang C, Ding Q, Sharma A, Wang F, Kim JS. RNA splicing based on reporter genes system: Detection, imaging and applications. Coord Chem Rev 2023. [DOI: 10.1016/j.ccr.2022.214929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Li H, Xie J, Zeng J, Wu J, Zhou J, Zhao W. VEGF gene polymorphisms regulate human retinal vascular endothelial cell proliferation and apoptosis through ASF/SF2-associated alternative splicing. Eur J Ophthalmol 2021; 32:2726-2734. [PMID: 34825587 DOI: 10.1177/11206721211058000] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This study investigated the effects of single nucleotide polymorphisms (SNPs) of the VEGF (vascular endothelial growth factor) gene, which are associated with susceptibility to age-related macular degeneration (AMD), on the expression of VEGF proteins (VEGF165 and VEGF165b) and their role in cell proliferation and apoptosis in human retinal vascular endothelial cells (hRVECs). Cell viability and VEGF165 and VEGF165b expressions were evaluated in hRVECs transfected with VEGF genes containing different SNPs (rs3025039, rs3025033, and rs10434). The Cell Counting Kit 8 assay, quantitative real-time PCR, western blotting, TUNEL assay, and enzyme-linked immunosorbent assay were used to examine the effects of VEGF gene SNPs on cell viability, VEGF165 and VEGF165b expressions, and cell apoptosis in hRVECs. The interaction and localization of the RNA-binding protein alternative splicing factor/splicing factor 2 (ASF/SF2) were assessed using RNA pull-down. Although VEGF165 expression decreased, VEGF165b levels increased significantly in hRVECs transfected with rs3025039, which decreased cell viability and induced apoptosis. The SNPs rs3025033 and rs10434 had no significant effects on VEGF165b protein production and apoptosis; however, they promoted cell proliferation. SNPs affected the interaction between RNA and ASF/SF2, a splicing factor for intron retention. Insulin-like growth factor-1 treatment induced the expression of VEGF165, but not VEGF165b, whereas SRPIN340 treatment, an inhibitor of ASF/SF2, increased VEGF165b protein levels. VEGF gene sequence variations affected hRVEC proliferation and apoptosis via alternative gene splicing. Thus, the regulation of splicing via ASF/SF2 could be a potential strategy in treating pathological neovascularization in patients with AMD.
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Affiliation(s)
- Honghui Li
- 588323Chengdu Aier Eye Hospital, Chengdu, China
| | - Jun Xie
- 588323Chengdu Aier Eye Hospital, Chengdu, China
| | - Junwen Zeng
- Zhongshan Ophthalmic Center, 194038Sun Yat-Sen University, Guangzhou, China
| | - Juan Wu
- Zhongshan Ophthalmic Center, 194038Sun Yat-Sen University, Guangzhou, China
| | - Jin Zhou
- 588323Chengdu Aier Eye Hospital, Chengdu, China
| | - Wei Zhao
- Department of Biomedical Sciences, 53025City University of Hong Kong, Hong Kong, China
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Star E, Stevens M, Gooding C, Smith CWJ, Li L, Ayine ML, Harper SJ, Bates DO, Oltean S. A drug-repositioning screen using splicing-sensitive fluorescent reporters identifies novel modulators of VEGF-A splicing with anti-angiogenic properties. Oncogenesis 2021; 10:36. [PMID: 33941763 PMCID: PMC8093282 DOI: 10.1038/s41389-021-00323-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 03/25/2021] [Accepted: 04/09/2021] [Indexed: 12/30/2022] Open
Abstract
Alternative splicing of the vascular endothelial growth factor A (VEGF-A) terminal exon generates two protein families with differing functions. Pro-angiogenic VEGF-Axxxa isoforms are produced via selection of the proximal 3' splice site of the terminal exon. Use of an alternative distal splice site generates the anti-angiogenic VEGF-Axxxb proteins. A bichromatic splicing-sensitive reporter was designed to mimic VEGF-A alternative splicing and was used as a molecular tool to further investigate this alternative splicing event. Part of VEGF-A's terminal exon and preceding intron were inserted into a minigene construct followed by the coding sequences for two fluorescent proteins. A different fluorescent protein is expressed depending on which 3' splice site of the exon is used during splicing (dsRED denotes VEGF-Axxxa and EGFP denotes VEGF-Axxxb). The fluorescent output can be used to follow splicing decisions in vitro and in vivo. Following successful reporter validation in different cell lines and altering splicing using known modulators, a screen was performed using the LOPAC library of small molecules. Alterations to reporter splicing were measured using a fluorescent plate reader to detect dsRED and EGFP expression. Compounds of interest were further validated using flow cytometry and assessed for effects on endogenous VEGF-A alternative splicing at the mRNA and protein level. Ex vivo and in vitro angiogenesis assays were used to demonstrate the anti-angiogenic effect of the compounds. Furthermore, anti-angiogenic activity was investigated in a Matrigel in vivo model. To conclude, we have identified a set of compounds that have anti-angiogenic activity through modulation of VEGF-A terminal exon splicing.
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Affiliation(s)
- Eleanor Star
- grid.8391.30000 0004 1936 8024Institute of Biomedical & Clinical Sciences, Medical School, College of Medicine and Health, University of Exeter, St Luke’s Campus, Exeter, EX1 2LU UK
| | - Megan Stevens
- grid.8391.30000 0004 1936 8024Institute of Biomedical & Clinical Sciences, Medical School, College of Medicine and Health, University of Exeter, St Luke’s Campus, Exeter, EX1 2LU UK
| | - Clare Gooding
- grid.5335.00000000121885934Department of Biochemistry, University of Cambridge, Hopkins Building, Tennis Court Road, Cambridge, CB2 1QW UK
| | - Christopher W. J. Smith
- grid.5335.00000000121885934Department of Biochemistry, University of Cambridge, Hopkins Building, Tennis Court Road, Cambridge, CB2 1QW UK
| | - Ling Li
- grid.8391.30000 0004 1936 8024Institute of Biomedical & Clinical Sciences, Medical School, College of Medicine and Health, University of Exeter, St Luke’s Campus, Exeter, EX1 2LU UK
| | - Monica Lamici Ayine
- grid.8391.30000 0004 1936 8024Institute of Biomedical & Clinical Sciences, Medical School, College of Medicine and Health, University of Exeter, St Luke’s Campus, Exeter, EX1 2LU UK
| | - Steve J. Harper
- grid.8391.30000 0004 1936 8024Institute of Biomedical & Clinical Sciences, Medical School, College of Medicine and Health, University of Exeter, St Luke’s Campus, Exeter, EX1 2LU UK
| | - David O. Bates
- grid.415598.40000 0004 0641 4263Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Queen’s Medical Centre, West Block, D floor, Nottingham, NG7 2UH UK
| | - Sebastian Oltean
- grid.8391.30000 0004 1936 8024Institute of Biomedical & Clinical Sciences, Medical School, College of Medicine and Health, University of Exeter, St Luke’s Campus, Exeter, EX1 2LU UK
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