Betamethasone alters NIT-1 cells proliferation and C-peptide secretion. (A) Percentage of viable NIT-1 cells (annexinV PE−, 7aad−) after 48 h of culture with increasing betamethasone (bet) concentrations [0.01; 0.1; 1 and 10 μM] (grey dots). Basal medium conditions (white circles) were included. Lines show the mean of 6 independent experiments (*p ≤ 0.05, Dunn’s test, Kruskal-Wallis). (B) Upper panel: relative ratio of NIT-1 cell growth after 8 days of culture with 0.1 μM bet (grey squares) or without bet (white circles). Data presented as mean ± s.d. of relative cell number (n = 5 independent experiments), this being relative cell number of each day referred to their respective day 0 cell number (+p ≤ 0.05, ++++p < 0.0001 for betamethasone-control comparison; *p ≤ 0.05, ****p < 0.0001 for intragroup comparison, Tukey’s test, Two-way Anova). Lower panel: percentage of viable NIT-1 cell line (annexinV PE−, 7aad−) during the 8 days of culture. (C) C-peptide concentration in NIT-1 cells’ supernatant after 48 h without bet (white box) or with 0.01 μM bet (grey box). Data are represented as ng/ml × 106cells/ml. Data shown as box and whisker plots (*p ≤ 0.05, Mann-Whitney test). (D) Relative median of fluorescence intensity (MFI) of CD44 and MHC class I in NIT-1 cells after 48 h of culture with bet at different concentrations [0.01; 0.1; 1 and 10 μM] (grey symbols) or without bet (white circles). Lines show the mean of n = 6 of relative MFI, this being MFI of each culture condition referred to their respective CM control (*p ≤ 0.05, **p < 0.01, ***p < 0.001 Dunn’s test).