<p>Safety of anti-VEGF treatments in a diabetic rat model and retinal cell culture</p>

Abstract

Purpose To analyze the safety of different concentrations of anti-VEGF on retinal cells. Methods Non-diabetic and streptozotocin (STZ)-induced diabetic rats received intravitreal rat anti-VEGF injections that had final vitreous concentrations of 0, 0.0625, 0.125 (clinical dose), and 0.25 mg/mL. Rats were also injected with the clinical dose of ranibizumab. TUNEL assay was performed on sectioned eyes to evaluate apoptotic cells. In vitro, rat retinal cell cultures were exposed to 0, 0.0625, 0.125 (clinical dose), and 0.25 mg/mL of ranibizumab for 48 and 72 hrs. Cellular metabolic activity was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, necrosis by lactate dehydrogenase (LDH), and apoptosis by cell death enzyme-linked immunosorbent assay (ELISA). Results Diabetic rats had a significant increase ( p <0.03) in apoptotic cell death at half the clinical dose, at the clinical dose, and at double the clinical dose. In vitro, MTT showed a significant decrease ( p <0.04) in cellular metabolic activity at the clinical dose and double the clinical dose compared to control at 48 and 72 hrs. LDH showed a significant increase ( p <0.04) in necrosis at the clinical dose and double the clinical dose compared to control at 48 and 72 hrs. ELISA showed a significant increase ( p <0.04) in apoptosis at half the clinical dose, at the clinical dose, and double the clinical dose, compared to control at 48 and 72 hrs. Conclusions Anti-VEGF treatment may be potentially detrimental to the retina by decreasing cellular metabolic activity and increasing cytotoxicity of retinal cells. The results provide a cautionary note to monitor both the retina and optic nerve status in patients undergoing frequent injections.

Antiangiogenic therapy in diabetic nephropathy: A double‑edged sword (Review)

“…VEGF is the primary mediator of abnormal diabetic glomerular angiogenesis. Although the beneficial effects of anti-VEGF antibodies have been confirmed in diabetic animal experiments, recent basic and clinical evidence has suggested that blocking VEGF signaling can lead to proteinuria and renal thrombotic microangiopathy ( 17 ), indicating the importance of the normal levels of VEGF in the kidney. Therefore, anti-angiogenic treatment of DN should eliminate the excessive angiogenic response of the glomeruli without accelerating endothelial damage.…”