10 research outputs found

    AMA0076, a Novel, Locally Acting Rho Kinase Inhibitor, Potently Lowers Intraocular Pressure in New Zealand White Rabbits with Minimal Hyperemia

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    PURPOSE. To determine whether ROCK inhibition for the treatment of glaucoma can be improved by using novel, locally acting Rho kinase (ROCK) inhibitors, such as AMA0076, that lower IOP without inducing hyperemia. METHODS. On-target potency of AMA0076 was compared with other ROCK inhibitors (Y-27632 and Y-39983) and conversion of AMA0076 into its functionally inactive metabolite was evaluated in rabbit eye tissues. Human trabecular meshwork (HTM) cell morphology, actin filaments, and focal adhesion were studied in vitro after exposure to AMA0076. The effect of AMA0076 on IOP was investigated in normotensive rabbits and a new, acute hypertensive rabbit model. Intraocular pressure lowering efficacy of AMA0076 was compared with pharmacologic treatments. Hyperemia after single topical dosing of AMA0076 and Y-39983 was scored. RESULTS. AMA0076 and Y-39983 showed similar on-target potency. AMA0076 was most stable in aqueous humor and converted into its metabolite in other eye tissues. Exposure of HTM cells to AMA0076 led to significant and reversible changes in cell shape and a decrease in actin stress fibers and focal adhesions. Both AMA0076 and Y-39983 provided an equivalent IOP control. Compared with latanoprost and bimatoprost, AMA0076 was more potent in preventing the IOP elevation in the acute hypertensive rabbit model. The degree of hyperemia was significantly lower in rabbits treated with AMA0076 then with Y-39983. CONCLUSIONS. AMA0076 is a locally acting ROCK inhibitor that is able to induce altered cellular behavior of HTM cells. Administration of AMA0076 effectively reduces IOP in ocular normotensive and acute hypertensive rabbits without causing distinct hyperemia

    The Effect of AMA0428, a Novel and Potent ROCK Inhibitor, in a Model of Neovascular Age-Related Macular Degeneration

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    Rho kinase (ROCK) is associated with VEGF-driven angiogenesis, as well as with inflammation and fibrosis. Therefore, the effect of AMA0428, a novel ROCK inhibitor, was studied in these processes, which highly contribute to the pathogenesis of neovascular AMD.status: publishe

    An atypical case of neurosarcoidosis presenting with neovascular glaucoma

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    Abstract Background Sarcoidosis, a multisystem, granulomatous disorder, sometimes manifests with a neuro-ophthalmic subtype. The latter can pose a diagnostic challenge, especially when ocular symptoms appear before systemic involvement, as the clinical picture then can be non-specific and systemic laboratory and standard imaging investigations can be negative. Findings A 71-year-old woman presented with a 4-month history of sudden-onset visual loss in the left eye. Slit lamp examination revealed anterior chamber cells, iris, and angle neovascularization. Fundoscopy showed a pale edematous optic nerve head surrounded with intraretinal hemorrhages and yellow retinal infiltrates. The vasculature was very narrow to absent. Indeed, fluorescein angiography filling was limited to the (juxta-)papillary region. An extensive systemic work-up revealed a monoclonal gammopathy and absence of any inflammatory markers. On MRI, a mass infiltration of the intraorbital and the intracranial optic nerve was visible. Additional PET-CT scan revealed hilar lymph nodes. A transbronchial biopsy demonstrating a non-caseating granulomatous lesion led to the diagnosis of sarcoidosis and thus neurosarcoidosis. Treatment with high-dose prednisone and azathioprine was started to avoid progression and subsequent visual loss in the other eye. Conclusions A patient with neurosarcoidosis presenting with compressive ischemic optic disc edema and neovascular glaucoma is described, increasing the diversity of clinical presentations and confirming the diagnostic challenge of neurosarcoidosis

    AMA0076, a novel, locally acting rho kinase inhibitor, potently lowers intraocular pressure in New Zealand white rabbits with minimal hyperemia

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    PURPOSE: To determine whether ROCK inhibition for the treatment of glaucoma can be improved by using novel, locally acting Rho kinase (ROCK) inhibitors, such as AMA0076, that lower IOP without inducing hyperemia. METHODS: On-target potency of AMA0076 was compared with other ROCK inhibitors (Y-27632 and Y-39983) and conversion of AMA0076 into its functionally inactive metabolite was evaluated in rabbit eye tissues. Human trabecular meshwork (HTM) cell morphology, actin filaments, and focal adhesion were studied in vitro after exposure to AMA0076. The effect of AMA0076 on IOP was investigated in normotensive rabbits and a new, acute hypertensive rabbit model. Intraocular pressure lowering efficacy of AMA0076 was compared with pharmacologic treatments. Hyperemia after single topical dosing of AMA0076 and Y-39983 was scored. RESULTS: AMA0076 and Y-39983 showed similar on-target potency. AMA0076 was most stable in aqueous humor and converted into its metabolite in other eye tissues. Exposure of HTM cells to AMA0076 led to significant and reversible changes in cell shape and a decrease in actin stress fibers and focal adhesions. Both AMA0076 and Y-39983 provided an equivalent IOP control. Compared with latanoprost and bimatoprost, AMA0076 was more potent in preventing the IOP elevation in the acute hypertensive rabbit model. The degree of hyperemia was significantly lower in rabbits treated with AMA0076 then with Y-39983. CONCLUSIONS: AMA0076 is a locally acting ROCK inhibitor that is able to induce altered cellular behavior of HTM cells. Administration of AMA0076 effectively reduces IOP in ocular normotensive and acute hypertensive rabbits without causing distinct hyperemia.status: publishe

    AMA0428, A Potent Rock Inhibitor, Attenuates Early and Late Experimental Diabetic Retinopathy

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    PURPOSE: Diabetic retinopathy (DR) is characterized by an early stage of inflammation and vessel leakage, and an advanced vasoproliferative stage. Also, neurodegeneration might play an important role in disease pathogenesis. The aim of this study was to investigate the effect of the Rho kinase (ROCK) inhibitor, AMA0428, on these processes. METHODS: The response to ROCK inhibition by AMA0428 (1 µg) was studied in vivo using the murine model for streptozotocin (STZ)-induced diabetes, focusing on early non-proliferative DR features and the oxygen-induced retinopathy (OIR) model to investigate proliferative DR. Intravitreal (IVT) administration of AMA0428 was compared with murine anti-VEGF-R2 antibody (DC101, 6.2 µg) and placebo (H2O/PEG; 1C8). Outcome was assessed by analyzing leukostasis using fluorescein isothiocyanate coupled concanavalin A (FITC-ConA) and vessel leakage (bovine serum albumin conjugated with fluorescein isothiocyanate; FITC-BSA)/neovascularization and neurodegeneration by immunohistological approaches (hematoxylin and eosin (H&E), terminal deoxynucleotidyl transferase-mediated biotinylated UTP nick end labeling (TUNEL), Brn3a). ELISA and Western blotting were employed to unravel the consequences of ROCK inhibition (1 µM AMA0428) on myosin phosphatase target protein (MYPT)-1 phosphorylation, endothelial nitric oxide synthase (eNOS) phosphorylation, and vascular endothelial growth factor (VEGF) levels in retinas of diabetic mice, on NF-κβ activity and ICAM-1 expression in endothelial cells (ECs). RESULTS: In vivo, AMA0428 significantly reduced vessel leakage and neovascularization, respectively, in the STZ and OIR model, comparable to DC101 therapy. Additionally, the ROCK inhibitor decreased neurodegeneration in both models and inhibited leukostasis by 30% (p < 0.05) in the STZ model (p < 0.05), while DC101 had no positive effect on the outcome of these latter processes. ROCK activity was upregulated in the diabetic retina and AMA0428 administration resulted in decreased phospho-MYPT-1, enhanced phospho-eNOS, and reduced VEGF levels. In vitro, AMA0428 interfered with NF-κβ activity, thereby inhibiting ICAM-1 expression in ECs. CONCLUSIONS: Targeting ROCK with AMA0428 effectively attenuated outcome in an early DR model (STZ) and a late vasoproliferative retinopathy model (OIR). These findings make AMA0428 a promising candidate with an additional anti-inflammatory and neuroprotective benefit for DR patients, as compared with anti-VEGF treatment.peerreview_statement: The publishing and review policy for this title is described in its Aims & Scope. aims_and_scope_url: http://www.tandfonline.com/action/journalInformation?show=aimsScope&journalCode=icey20status: publishe

    Bevacizumab revisited: its use in different mouse models of ocular pathologies

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    Previous reports have yielded conflicting data on the activity of bevacizumab (Avastin), a recombinant humanized monoclonal antibody against VEGF-A, in the mouse. The current study was designed to further explore the use of this VEGF inhibitor in various murine models of ocular diseases and compare it to the widely used murine anti-VEGF-R2 neutralizing antibody (DC101).peerreview_statement: The publishing and review policy for this title is described in its Aims & Scope. aims_and_scope_url: http://www.tandfonline.com/action/journalInformation?show=aimsScope&journalCode=icey20status: publishe

    The Role of LOX and LOXL2 in the Pathogenesis of an Experimental Model of Choroidal Neovascularization

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    We investigated whether lysyl oxidase (LOX) and lysyl oxidase-like 2 (LOXL2) play a role in an experimental model of choroidal neovascularization (CNV). The therapeutic potential of antibodies against LOX (M64) and LOXL2 (AB0023) was evaluated in a murine laser-induced CNV model.status: publishe
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