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Effect of Integrin α5β1 Inhibition on SDF-l/CXCR4-mediated Choroidal Neovascularization

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Specialty Ophthalmology
Date 2018 Jun 5
PMID 29862169
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Abstract

Aim: To investigate the roles of integrins in choroidal neovascularization (CNV) and their associations with the stromal cell-derived factor-1 (SDF-1)/CXCR4 axis.

Methods: CNV lesions were induced in mice using laser photocoagulation. After CNV induction, all animals were randomly assigned to: control, SDF-1, SDF-1+age-related macular degeneration (AMD) 3100 (CXCR4 inhibitor), and SDF-1+ATN161 (integrin α5β1 inhibitor) groups; their effects on CNV progression were observed using hematoxylin eosin (HE) staining, fundus fluorescein angiography (FFA) grading and optical coherence tomography (OCT), and their effects on CXCR4/integrin α5 expression were evaluated using Western blot and double immunofluorescence staining. Hypoxia-exposed endothelial cells (ECs) were used to simulate CNV , they were treated with SDF-1, combined with CXCR4 siRNA/AMD3100 or ATN161, and expression of integrin α5, cell migration and tube formation were analyzed.

Results: Integrin subunit α5 increased at 3 and 7 day and decreased at 14 day in CNV mice, with no significant change of β1-integrin. CXCR4 expression in CNV mice had persistent increase within 14d after induction. SDF-1 treatment significantly promoted the CNV progression during 3-14d. The mean CNV length in AMD3100 and ATN161 group at day 7 was 270.13 and 264.23 µm in HE images, significantly lower than the mean length in SDF-1 (345.70 µm) group. AMD3100 and ATN161 also significantly reduced thickness and leakage of CNV induced by SDF-1. Mean integrin α5 positive area in SDF-1 group reached 2.31×104 µm, significantly higher than control (1.25×104 µm), which decreased to 1.78×104 µm after AMD3100 treatment. About 61.36% of ECs in CNV lesions expressed α5 in SDF-1 group, which significantly decreased to 43.12% after AMD3100 treatment. , integrin α5 peaked by 6 folds after 6h of hypoxia exposure and CXCR4 gradually increased by up to 2.3 folds after 24h of hypoxia. Approximately 25.12% of ECs expressed integrin α5 after SDF-1 stimulation, which decreased to 7.2%-9.5% after si-CXCR4 or AMD3100 treatment. ATN161 exerted an inhibitory effect comparable to that of si-CXCR4 on EC migration and tube formation in the presence of SDF-1.

Conclusion: SDF-1/CXCR4 signaling induces integrin α5β1 expression in ECs to promote CNV.

References
1.
Friedlander M, Theesfeld C, Sugita M, Fruttiger M, Thomas M, Chang S . Involvement of integrins alpha v beta 3 and alpha v beta 5 in ocular neovascular diseases. Proc Natl Acad Sci U S A. 1996; 93(18):9764-9. PMC: 38503. DOI: 10.1073/pnas.93.18.9764. View

2.
Wang B, Wang W, Niu W, Liu E, Liu X, Wang J . SDF-1/CXCR4 axis promotes directional migration of colorectal cancer cells through upregulation of integrin αvβ6. Carcinogenesis. 2013; 35(2):282-91. DOI: 10.1093/carcin/bgt331. View

3.
Xu D, Davila J, Rahimi M, Rebhun C, Alibhai A, Waheed N . Long-term Progression of Type 1 Neovascularization in Age-related Macular Degeneration Using Optical Coherence Tomography Angiography. Am J Ophthalmol. 2017; 187:10-20. DOI: 10.1016/j.ajo.2017.12.005. View

4.
Feng L, Ju M, Lee K, Mackey A, Evangelista M, Iwata D . A Proinflammatory Function of Toll-Like Receptor 2 in the Retinal Pigment Epithelium as a Novel Target for Reducing Choroidal Neovascularization in Age-Related Macular Degeneration. Am J Pathol. 2017; 187(10):2208-2221. PMC: 5809578. DOI: 10.1016/j.ajpath.2017.06.015. View

5.
Jones J, Marian D, Weich E, Engl T, Wedel S, Relja B . CXCR4 chemokine receptor engagement modifies integrin dependent adhesion of renal carcinoma cells. Exp Cell Res. 2007; 313(19):4051-65. DOI: 10.1016/j.yexcr.2007.07.001. View