Fig. 4

WFS1 mutation (p.W690fsX706) induces cell apoptosis by increasing ER stress. HK-2 cells with stable knockdown of WFS1 were respectively transfected with wild type (WT), p.W690fsX706 (p.W690X), p.F883fsX950 (p.F883X) WFS1 expression plasmids and empty vector. a Relative expression level of WFS1 was verified by qRT-PCR in HK-2 cells after indicated interventions. b At 48 h post-transfection, cell viability of HK-2 cells was measured by CCK-8 assay. c After 48 h of transfection, TUNEL staining of HK-2 cells was carried out, and representative images were shown individually and merged. TUNEL-positive HK-2 cells were calculated. Magnification: 200X. d After transfection with indicated expression plasmids for 48 h, HK-2 cells stained with Annexin V and propidium iodide (PI) were analyzed by flow cytometry for cell apoptosis assessment. e Relative mRNA levels of ER stress-related markers (GRP78, XBP1 and CHOP) were measured by qRT-PCR. f The levels of WFS1 protein and ER stress-related proteins (ATF-6, BiP, XBP1 and CHOP) in HK-2 cells were analyzed by western blotting. β-Actin served as a loading control. Values were represented as mean ± SEM. One-way ANOVA, Tukey’s post-hoc test, *P < 0.05, **P < 0.01 and ***P < 0.001. ns means no statistical significance