Fig. 4: ManN affects protein glycosylation.

a Reduction of VEGFR2 molecular mass following ManN treatment. BCECs were treated with various hexosamines, their derivatives, and monosaccharides at 40 μM or with VEGF at 5 ng/ml for 24 h. VEGFR2 western blot analysis was performed. b Dose-dependent effects of ManN on VEGFR2 molecular mass in BCECs. c Mannose could dose-dependently reverse the effect of 2 mM ManN on VEGFR2 molecular mass change, whereas mannose alone had no effect even at 10 mM. d 5 mM mannose could completely reverse the bell-shaped effects of ManN on BCEC proliferation with or without 5 ng/ml VEGF. BCECs plated in 96 wells were allowed to attach, followed by ManN addition. Two hours later, cells were treated with different concentrations of Mannose, with or without VEGF. Six days later, cell proliferation was quantified using AlamarBlue®. n = 3 independent samples. e Effects of ManN are reversible. BCECs, after treatment with 40 μM ManN for 24 h, were washed three times with low-glucose DMEM. Cells were kept in low-glucose DMEM for additional 8 or 24 h. VEGFR2 western blot analysis was performed. f Reduction of molecular mass of VEGFR2, Neuropilin-1, CD31, and c-met in HUVEC following ManN treatment at various concentrations. g Reduction of molecular mass of VEGFR2, β1 integrin, and bFGFR1 in hDMVECs by ManN at various concentrations. β-actin served as the loading control. Data are means +/− SD, asterisks denote a significant difference compared with the control. For each study, a representative experiment is shown from two to five independent studies. Statistical analysis was done by two-tailed, two-sample unequal variance t test. *p < 0.05, **p < 0.01. Data are provided as a Source data file.