Effects of VEGF inhibitors on human retinal pigment epithelium under high glucose and hypoxia

Abstract

Background Retinal pigment epithelium (RPE) is known to secrete factors important for retinal homeostasis. How this secretome changes in diabetic eyes treated with anti‐vascular endothelial growth factor (VEGF) inhibitors is unclear. Methods Diabetic conditions were simulated in vitro using ARPE‐19 cell‐line culture, with high glucose (25 mM) culture media, and hypoxia was chemically induced using cobalt chloride. Stress was assessed using cell viability assays as well as Western blots and enzyme‐linked immunosorbent assay (ELISA) for production of HIF‐1a and VEGF‐A. Production of neurotrophic factors was quantified once conditions were established using ELISA under stress with and without the addition of VEGF inhibitors. Changes were analysed with one‐way ANOVA. Results Hypoxia downregulated pigment epithelium‐derived factor (PEDF) expression. The addition of bevacizumab, ranibizumab and aflibercept in normoxic conditions all led to a significant downregulation of PEDF. Glucose concentration had no effect on secretion of PEDF. Brain‐derived neurotrophic factor (BDNF) secretion was downregulated in high glucose and was upregulated in hypoxia. Placental growth factor (PlGF) secretion by ARPE‐19 was undetectable by ELISA. Conclusions We found that hypoxia, high glucose or VEGF inhibitors affected secretion of neurotrophic factors. This variation under different conditions may influence neuron and photoreceptor survival in the diabetic state and VEGF inhibitor treated eyes.

Rice Bran and Vitamin B6 Suppress Pathological Neovascularization in a Murine Model of Age-Related Macular Degeneration as Novel HIF Inhibitors

“…We could not see a significant increase in HIF-2α expression under a CoCl 2 -induced hypoxic condition, and rice bran and vitamin B6 did not change its expression. Taken together, it indicates that HIF-1α (rather than HIF-2α) might be the major regulator in ARPE-19 cells under this hypoxic condition, which is in agreement with several previous reports using ARPE-19 cells [33][34][35].…”

TREM-2-p38 MAPK signaling regulates neuroinflammation during chronic cerebral hypoperfusion combined with diabetes mellitus

“…The duration of hypoxia and glucose concentrations in vitro systems should be of practical relevance to the brain in vivo. However, the duration of hypoxia and glucose concentrations to induce hypoxia and hyperglycemia was varied in different in vitro models [20,21,27]. Our data showed that cells exposed to high glucose (33 mM) 24 h prior to a 24 h anaerobic incubation (3% O 2 ) resulted in moderate microglial cell death as compared with hypoxia (3% O 2 ) alone for 24 h.…”

Overexpression of METTL3 attenuates high-glucose induced RPE cell pyroptosis by regulating miR-25-3p/PTEN/Akt signaling cascade through DGCR8

“…Recent studies found that methyltransferase-like 3 (METTL3) mediated m 6 A modifications were closely related with the development of type 2 diabetes mellitus (T2DM) [6], but it was still unclear whether METTL3 regulated DR progression. The high-glucose treated retinal pigment epithelium (RPE) cells were used in this study as the in vitro models for DR research according to the previous studies [36][37][38]. The results showed that METTL3 was low expressed in the peripheral venous blood samples collected from T2DM patients compared to the normal volunteers.…”