Aim: To evaluate the antiproliferative and cytotoxic properties of bevacizumab, a monoclonal antibody against vascular endothelial growth factor (VEGF), on human retinal pigment epithelium (ARPE19) cells, rat retinal ganglion cells (RGC5), and pig choroidal endothelial cells (CEC). Methods: Monolayer cultures of ARPE19, RGC5, and CEC were used. Bevacizumab (0.008-2.5 mg/ml), diluted in culture medium, was added to cells that were growing on cell culture dishes. Cellular proliferative activity was monitored by 59-bromo-29-deoxyuridine (BrdU) incorporation into cellular DNA and the morphology assessed microscopically. For cytotoxicity assays ARPE19, RGC5, and CEC cells were grown to confluence and then cultured in a serum depleted medium to ensure a static milieu. The MTT test was performed after 1 day. The ''Live/Dead'' viability/cytotoxicity assay was performed and analysed by fluorescence microscopy after 6,12,18,24, 30, 36, and 48 hours of incubation. Expression of VEGF, VEGF receptors (VEGFR1 and VEGFR2) and von Willebrand factor was analysed by immunohistochemistry. Results: No cytotoxicity of bevacizumab on RGC5, CEC, and ARPE19 cells could be observed after 1 day. However, after 2 days at a bevacizumab concentration of 2.5 mg/ml a moderate decrease in ARPE19 cell numbers and cell viability was observed. Bevacizumab caused a dose dependent suppression of DNA synthesis in CEC as a result of a moderate antiproliferative activity (maximum reduction 36.8%). No relevant antiproliferative effect of bevacizumab on RGC5 and ARPE19 cells could be observed when used at a concentration of 0.8 mg/ml or lower. CEC and ARPE 19 cells stained positively for VEGF, VEGFR1, and VEGFR2. More than 95% of the CEC were positive for von Willebrand factor. Conclusions: These experimental findings support the safety of intravitreal bevacizumab when used at the currently applied concentration of about 0.25 mg/ml. Bevacizumab exerts a moderate growth inhibition on CEC when used in concentrations of at least 0.025 mg/ml. However, at higher doses (2.5 mg/ml) bevacizumab may be harmful to the retinal pigment epithelium.
Bevacizumab, pegaptanib and ranibizumab significantly suppress choroidal endothelial cell proliferation. However, when used at the currently established doses none of the drugs was superior over the others in respect to endothelial cell growth inhibition. The biocompatibility of all three drugs--including the off-label bevacizumab--seems to be excellent when used at the currently recommended intravitreal dose.
ABSTRACT.Purpose: Monoamine receptors are found throughout the body. Reports about the presence of monoamine receptors in the human cornea are inconsistent. Methods: Immunohistochemistry, immunofluorescence and immunoblotting were used to localize monoamine receptor sites on human corneal epithelium and endothelium. Results: Antibodies to alpha-1, beta-1 and beta-2 adrenergic receptors and to D1-like and 5HT-7 receptors were bound in corneal epithelium. Antibodies to alpha-1, alpha-2A, beta-1 and beta-2 adrenergic receptors and to 5HT-7 receptors were bound in corneal endothelium.Conclusions: Our data demonstrate the presence of several monoamine receptors in the human cornea. These receptors may play a role in the regulation of fluid transport or corneal homeostasis.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.