A. XBP1s overexpression in cardiomyocytes led to an increase in cell size. NRVMs were infected by adenovirus expressing control GFP or XBP1s, followed by PE treatment. Note that the XBP1s-expressing virus is bi-cistronic for GFP and XBP1s, and GFP positivity indicates infection by either GFP-only control or XBP1s-GFP virus. Scale bar: 20 μm.
B. Quantification of A. N = 34 for veh/Ad GFP; 33 for veh/Ad XBP1s; 51 for PE/Ad GFP; 107 for PE/Ad XBP1s.
C. Protein synthesis was elevated by XBP1s overexpression as revealed by 3H-leucine incorporation. N = 3 for PE/Ad XBP1s. N = 6 for the other groups.
D. XBP1s overexpression potentiated PE-induced upregulation of Rcan1.4 at the protein level. As a control, Rcan1.1 did not show a similar trend.
E. Quantification of D. N = 5 for Rcan1.4/Ad XBP1s. N = 6 for the other groups. Two-way ANOVA analysis was conducted, followed by Tukey’s test. *, P<0.05; **, P<0.01; ***, P<0.001.