Dabigatran and Wet AMD, Results From Retinal Pigment Epithelial Cell Monolayers, the Mouse Model of Choroidal Neovascularization, and Patients From the Medicare Data Base

Abstract

BackgroundAge-related macular degeneration (AMD), the leading cause of irreversible blindness in elderly Caucasian populations, includes destruction of the blood-retina barrier (BRB) generated by the retinal pigment epithelium-Bruch’s membrane complex (RPE/BrM), and complement activation. Thrombin is likely to get access to those structures upon BRB integrity loss. Here we investigate the potential role of thrombin in AMD by analyzing effects of the thrombin inhibitor dabigatran.Material and MethodsMarketScan data for patients aged ≥65 years on Medicare was used to identify association between AMD and dabigatran use. ARPE-19 cells grown as mature monolayers were analyzed for thrombin effects on barrier function (transepithelial resistance; TER) and downstream signaling (complement activation, expression of connective tissue growth factor (CTGF), and secretion of vascular endothelial growth factor (VEGF)). Laser-induced choroidal neovascularization (CNV) in mouse is used to test the identified downstream signaling.ResultsRisk of new wet AMD diagnosis was reduced in dabigatran users. In RPE monolayers, thrombin reduced TER, generated unique complement C3 and C5 cleavage products, led to C3d/MAC deposition on cell surfaces, and increased CTGF expression via PAR1-receptor activation and VEGF secretion. CNV lesion repair was accelerated by dabigatran, and molecular readouts suggest that downstream effects of thrombin include CTGF and VEGF, but not the complement system.ConclusionsThis study provides evidence of association between dabigatran use and reduced exudative AMD diagnosis. Based on the cell- and animal-based studies, we suggest that thrombin modulates wound healing and CTGF and VEGF expression, making dabigatran a potential novel treatment option in AMD.

Serum Amyloid A 4 as a Common Marker of Persistent Inflammation in Patients with Neovascular Age-Related Macular Degeneration and Polypoidal Choroidal Vasculopathy

“…nAMD patients’ vitreous fluid has been shown to contain higher levels of P00734 (prothrombin) compared with healthy controls, while P02749 (Beta-2-glycoprotein 1, APOH) is not expressed in neural retina and/or Retinal pigment epithelium (RPE)-choroid. 30 , 31 P35542 (Serum amyloid A-4 protein), a member of the SAA protein family, appears at the site of inflammation and is highly expressed in all inflammatory disorders. Thus far, there are no data on the association between SAA4 and nAMD or PCV in the literature.…”

Effect of antibody-mediated connective tissue growth factor neutralization on lung edema in ventilator-induced lung injury in rats

“…CTGF modulates inflammatory responses, which are not only precursors to the fibrotic process, but also play a role in the regulation of vascular permeability. Indeed, increased CTGF levels were paralleled by increased paracellular permeability in cultured epithelial cells exposed to cyclic stretch (Ran et al 2023 ) or following thrombin administration (Akter et al 2022 ). In an experimental animal model of lung injury, increased CTGF levels were paralleled by pulmonary edema (Yang et al 2015 ) and blocking of CTGF reduced pulmonary interstitial edema in an experimental fibrosis model (Bickelhaupt et al 2017 ).…”

Exploring the Therapeutic Potential of Elastase Inhibition in Age-Related Macular Degeneration in Mouse and Human

“…Confluent cells were trypsinized and equal cells were seeded on 24 mm transwell inserts (Costar, 0.4 µm pore size). After reaching confluency the FBS percentage in the media was gradually reduced to 2%, and then to 1% to promote cell differentiation and tight junction formation as described by us earlier [33,45]. Polarity of the monolayers has been documented by our collaborator [45] as well as by us [42,73] in part based on polarized secretion of growth factors and complement components.…”

“…CNV was induced at 8 weeks of age, and animals were dosed weekly starting a day before the laser treatment. Volume intensity projections in OCT images were used to quantify the CNV lesion areas as previously published [33] on days 7-and 21 post-CNV induction. CNV-sizes were significantly reduced in A1AT-injected mice compared to the PBS-injected controls at both time points (Figure 2G-H).…”

“…For OCT, mice were anesthetized with ketamine/xylazine before imaging, the pupils were dilated (2.5% phenylephrine HCl and 1% atropine sulfate) and eyes were kept moist using GenTeal (Alcon) lubricant throughout the procedure. CNV lesion sizes were measured based on individual pixel sizes (µm × µm) from OCT volume intensity projections as described previously [33,68]; retinal layer thicknesses were measured in cross sections using the auto segmentation with InVivoVue™ Diver software (Bioptigen).…”