Fig. 2.

Mannose inhibits ERS in IECs by normalizing protein N-glycosylation. A Colon tissues harvested from healthy and colitic mice (4 days after DSS challenge, n = 3/group) were subjected to RNA sequencing analysis. The levels of ERS-associated genes were analyzed. B The expression of GRP78, CHOP, and CASP12 in IECs from healthy (n = 4/group) and colitic (n = 7/group) mice was analyzed by QPCR. C The levels of cleaved caspase-3 in IECs were evaluated by immunoblotting. D Colon explants were isolated from colitic mice (n = 5/group) and cultured in the presence or absence of mannose (10 mM). GRP78 and CHOP expression was evaluated by immunoblotting. M = mannose. E The levels of the indicated ISC markers were analyzed by RNA sequencing. F The number of Ki67⁺ cells was determined by immunofluorescence staining using Lgr5^EGFP reporter mice (n = 3/group). G Colon crypts were isolated from healthy (n = 4/group) or DSS-fed (n = 7/group) mice and cultured in vitro for 5 days. The viability of the organoids was analyzed by an MTT assay. H, I HCoEpiC cells (H) and colon organoids (I) were treated with Ctrl^SN or Co^SN in the presence or absence of mannose (10 mM) for 24 h, and the levels of GRP78 and CHOP were measured by QPCR. J, K The viability of HCoEpiC cells (J) and colon organoids (K) was evaluated by CCK8 and MTT assays, respectively. L Schematic showing the mechanisms of ERS induction by 2DG and Tm. M IECs were treated with 2DG or Tm in the presence or absence of mannose for 24 h, and GPR78 and CHOP expression was evaluated by QPCR. N Cell viability was evaluated by a CCK8 assay. O IECs were stimulated with Co^SN for 24 h, and protein glycosylation was evaluated by flow cytometry using conA staining. P The level of glycosylated proteins in colon tissues was measured by conA staining. The data are presented as the means ± SEMs. *p < 0.05; **p < 0.01; ***p < 0.001; two-tailed unpaired Student’s t test