Topical application of a G-Quartet aptamer targeting nucleolin attenuates choroidal neovascularization in a model of age-related macular degeneration

Abstract

Choroidal neovascularization (CNV) associated with the ‘wet’ form of age related macular degeneration (AMD) is one of the most common causes of central vision loss among the elderly. The ‘wet’ form of AMD is currently treated by intravitreal delivery of anti-VEGF agents. However, intravitreal injections are associated with complications and long-term inhibition of VEGF leads to macular atrophy. Thus, there is currently an unmet need for the development of therapies for CNV that target molecules other than VEGF. Here, we describe nucleolin as a novel target for the ‘wet’ form of AMD. Nucleolin was found on the surface of endothelial cells that migrate from the choroid into the subretinal space in the laser-induced model of ‘wet’ AMD. AS1411 is a previously described G-quartet oligonucleotide that has been shown to bind nucleolin. We found that AS1411 inhibited the formation of tubes by human umbilical vein endothelial cells (HUVECs) by approximately 27.4% in vitro. AS1411 co-localized with the site of laser induced CNV in vivo. Intravitreally injected AS1411 inhibited laser-induced CNV by 37.6% and attenuated infiltration of macrophages by 40.3%. Finally, topical application of AS1411 led to a 43.4% reduction in CNV. Our observations have potential implications for the development of therapies for CNV and specifically for the ‘wet’ form of AMD.

AS1411 Nucleolin-Specific Binding Aptamers Reduce Pathological Angiogenesis through Inhibition of Nucleolin Phosphorylation

“…Previous studies in our group revealed that there is a cell surface localization of NCL in angiogenic cells in a suture-induced corneal neovascularization model [ 44 ] and that AS411 was able to inhibit corneal neovascularization downregulating the angiogenic miR-21 and-221 molecules [ 45 ]. Our results are consistent with previous studies where intravitreal injection or topical application of G-Quartet aptamer targeting NCL ameliorated choroidal neovascularization in a model of age-related macular degeneration [ 53 ]. Recently, proteomic analysis of OIR-treated retinas and samples obtained from human PDR patients showed that the vascular leakage positively correlates with the amount of MyH9, a heavy chain of nonmuscle myosin IIA [ 54 ].…”

“…All mice at P14 were anaesthetized using sevoflurane (Abbott Laboratories, Mexico City, Mexico), and treated with one drop of tetracaine, tropicamide and 2.5% phenylephrine (Sophia, Guadalajara, Mexico) to reduce corneal reflex and dilate pupils, respectively. To determine the effect of AS1411 in the OIR mice model, mice exposed to hyperoxia were randomly divided into four different groups and injected with 0.5 µL (final volume) using a Hamilton syringe depending of the group: (A) group of OIR treated with 0.01 M sterile PBS as a positive control of angiogenesis or as a negative control of treatment, (B) group of OIR treated with 0.2 nmol sterile AS1411 as previously reported by Leaderer et al [ 53 ], (C) group of OIR treated with 0.2 nmol sterile CRO which is the negative control for AS1411 due to its changes in citosines instead of guanines, and (D) group treated with 20.8 µM sterile ranibizumab corresponding to a negative control of angiogenesis. The procedure of intravitreal injection was performed using a 10 µL gastight Hamilton syringe equipped with a 33-gauge sharp needle under a stereoscopic microscope (Carl Zeiss, Jena, Germany).…”

Inhibition of thyroid hormone receptor locally in the retina is a therapeutic strategy for retinal degeneration

“…In terms of disease management, the eye has advantages over other organs because of its accessibility to topically delivered therapeutics (i.e., eye drops) (26,(62)(63)(64). We demonstrated that topical delivery of TR inhibitor protects cones in retinal-degeneration model mice.…”

G-quartet oligonucleotide mediated delivery of proteins into photoreceptors and retinal pigment epithelium via intravitreal injection

“…Phase II of a clinical study has just been completed for the nucleolin-targeting aptamer, AS1411, investigating efficacy as a therapy for Acute Myeloid Leukemia (https://clinicaltrials.gov/ct2/show/NCT00512083). We have recently found the potential of AS1411 delivered by either intravitreal injection or by topical application to inhibit choroidal neo-vascularization in a murine model of AMD (Leaderer et al, 2015). To our knowledge this is the first study, however, demonstrating the use of an aptamer as a protein delivery system in the eye.…”

“…We have recently found that topical application of AS1411 can significantly reduce endothelial cell proliferation in the laser-induced model of choroidal neovascularization (Leaderer et al, 2015). In the present study, we investigate the presence of cell surface nucleolin, the target of AS1411, on cells of the murine, non-human primate and human retina.…”