Effects of LPS on TLR4 expression, cell viability and insulin synthesis in murine insulinoma cells. 5 × 105 MIN-6 cells treated with LPS (50 ng/mL) were analyzed after 48 h for gene expression, cell viability and insulin production. (a) TLR4 and CD14 mRNA expression is shown as mean ± SD (n = 3) of relative fold increase compared to control (untreated) cells. Representative flow cytometry histogram of (b) percent TMRE-positive or (d) percent NG-positive cells treated with LPS (red line), untreated or control cells (green line) and isotype-matched control for TLR4 staining (dotted black line). Relative percentage of (c) TMRE positive or (e) NG positive cells expressed as mean ± SD (n = 3). In all cases, statistically significant differences are indicated as (*) p < 0.05 and (**) p < 0.005, compared to non-treated control cells.