Extended Data Figure 3: ER stress-induced activation of PERK/eIF2α induces autophagy in Xbp1-deficiency.
From: Paneth cells as a site of origin for intestinal inflammation
a, Immunoblot of shXbp1 and shCtrl MODE-K cells co-silenced with Perk (siPerk) or scrambled siRNA. b, Cumulative densitometry of the immunoblot in Fig. 1g and two additional experiments (not shown, n = 10; unpaired Student’s t-test; mean ± s.e.m.). c, p-eIF2α immunohistochemistry of small intestinal epithelium. Scale bars, 50 μm. d, mRNA expression levels of Map1lc3b (LC3b) and Atg7 relative to Gapdh in shCtrl and shXbp1 MODE-K cells (n = 3; unpaired Student’s t-test; mean ± s.e.m.). e, Accumulation of GFP–LC3 punctae after salubrinal and 3-day tamoxifen treatment according to timeline in Extended Data Fig. 2a (n = 5). Scale bars, 5 μm. f, Immunoblot of primary epithelial cell scrapings from small intestine upon vehicle or salubrinal treatment according to the timeline in g (n = 2). Note the increased relative levels of LC3 conversion and CHOP, a transcriptional target of ATF4, in salubrinal-treated mice. g, Timeline of salubrinal experiment. Results are reported in f and Fig. 1k. h, Gadd34 expression in shCtrl and shXbp1 MODE-K cells co-silenced for Gadd34 (siGadd34) and control (siCtrl) (one-way ANOVA with post-hoc Holm’s corrected unpaired Student’s t-test; mean ± s.e.m.). i, Cells as in h were immunoblotted. j, Immunoblot of crypt lysates (n = 2/4/2). Results represent three (a, h, i) independent experiments. *P < 0.05, **P < 0.01, ***P < 0.001.
