Fig. 1.

Endoplasmic reticulum stress (ERS) is upregulated in type 2 diabetic rats and diabetic humans with atrial fibrillation (AF).

A–H, Rat model of type 2 diabetes by high-fat feeding + low-dose streptozotocin (STZ) injection with or without 4-phenyl butyric acid (4-PBA) for 8 weeks. Representative Western blot results and analysis of the protein expression in the three groups are shown. A, Western blot detection of GRP78 protein levels. B, Quantification of GRP78 protein levels in (A). C, Western blot detection of CHOP protein levels. D, Quantification of CHOP protein levels in (C). E, Western blot detection of XBP1 protein levels. F, Quantification of XBP1 protein levels in (E). Values are the mean ± SEM. n = 6 per group. *P < 0.05, #P < 0.01, ANOVA with Bonferroni post-test. G, Analysis results of left atrial diameter (LAD). H, Quantification of the inducibility of AF. Values are the mean ± SEM. n = 7 in control group, n = 8 in T2DM group, n = 10 in 4-PBA group,. *P < 0.05, Chi-square test with Pearson's.