Metformin Reduces Lipotoxicity-Induced Meta-Inflammation in β-Cells through the Activation of GPR40-PLC-IP3 Pathway

Figure 1

Adjustment GPR40 expression altered metformin’s protective function on lipotoxicity in β-cells. All data is presented as of three independent experiments. (a) Metformin reduces PA-induced apoptosis in β-cells. (A1) Representative images from fluorescent microscopy in each group. The white arrow indicates apoptotic cells. (A2) Collective analyses of all three independent experiments. (b) Detection of basal insulin secretion (BIS) and glucose-stimulated insulin secretion (GSIS) by ELISA. (c) Expression of TLR4, NF-κB subunit P65, and GPR40 detected by Western blotting. (C1) Representative Western blot images for each group. (C2) The ratio of target protein to β-actin. (d, e) GPR40 protein expression levels detected by Western blotting in GPR40-overexpressing transfected cells and siRNA transfected cells (siRNA). Regulation of GPR40 expression and the protective effects of metformin on PA -induced β-cell apoptosis (f), insulin secretion disorder (g), and TLR4 and NF-κB subunit P65 protein expression (h). (a–c) ^A vs. NC group (without PA and MF), ^B vs. 0.5 mmol/L PA group, ^C vs. 0.5 mmol/L PA+25 μmol/L MF group, and ^D vs. 0.5 mmol/L PA+50 μmol/L MF group. (d, e) ^A vs. NC group, ^B vs. NC+vector group. (f–h) ^A vs. NC group (without PA and MF), ^B vs. 0.5 mmol/L PA group, and ^C vs. 0.5 mmol/L PA+100 μmol/L MF group.

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