Effect of Insig-1 overexpression on nSREBP-1c and proteins related to ER stress pathway in INS-1 cells. INS-1 and INS-1-Insig-1 cells were stimulated with 11.2 mM and 25.0 mM glucose for 0, 24 and 72 h. A) nSREBP-1c and p-IRE1α pathway of ER stress related proteins were detected by Western blot. GAPDH was used as control for protein loading. Equal amount of proteins (50 μg) were loaded. B) Relative protein expression compared to GAPDH, data are the means ± SE of three independent experiments; *, P < 0.05, **, P < 0.01 VS INS-1 cells at the same time point.