Figure 3.

ER stress is a rate-limiting switch controlling mucus secretion

(A) Scheme depicting ER stress reduction by inhibiting eIF2α dephosphorylation via salubrinal, by TUDCA, or by activating ATF6 via AA147.

(B–D) Measurements of mucus thickness in colonic sections from mice treated with TUDCA or salubrinal as indicated, and stained with Alcian blue. Scale bars, 50 μm. Each dot represents a mouse.

(E) Measurements of mucus thickness in colonic sections from mice treated with the ATF6 activator AA147 and stained with Alcian blue. Each dot represents a mouse.

(F) Scheme depicting mucus growth rate measurements. Created with BioRender.com.

(G) Mucus growth over time ± SEM.

(H) Mucus growth rate. Lines connect tissues from the same mouse.

^∗p < 0.05, ^∗∗∗p < 0.001; ^∗∗∗∗p < 0.0001; (C) one-way ANOVA; (E) Student’s t test; (G) nonlinear regression; (H) paired t test. WT, wild type; F121A, Becn1^F121A; TUDCA, tauroursodeoxycholic acid.