Original ResearchFull Report: Basic and Translational—Alimentary TractThe Tight Junction Protein ZO-1 Is Dispensable for Barrier Function but Critical for Effective Mucosal Repair
Graphical abstract
Section snippets
Materials and Methods
Mouse studies followed protocols approved by institutional animal care and use committees and used vil-mRFP1-ZO-1 (Tg(Vil1-mRFP1/TJP1)#Tjr, MGI:5584023), Tjp1f/f (Tjp1tm2c(KOMP)Wtsi, MGI:6272009), vil-Cre (B6.Cg-Tg(Vil1-cre)20Syr, MGI:3053819), vil-CreERT2 (B6.Cg-Tg(Vil1-cre/ERT2)23Syr/J, MGI:6278020), H2B-mCherry (R26-H2B-mCherry, CDB:CDB0239K), and GFP-β-actin (Pfn1tm2.1(GFP/ACTB)Wit, MGI:5568700) mice. Tjp1f/f littermates were used as wild-type (WT) controls for Tjp1f/f-vil-Cre (ZO-1KO.IEC)
ZO-1 Expression Is Down-regulated in Inflammatory Bowel Disease
To comprehensively assess tight junction protein transcription in IBD, we screened the GDS3268 RNA microarray data set, which includes biopsy specimens from 67 patients with ulcerative colitis and 31 healthy control individuals.8 This confirmed published results showing increased CLDN1 and CLDN2 and reduced OCLN, CLDN4, and CLDN8 expression in ulcerative colitis (Figure 1A).6,7 These changes were generally consistent across 5 additional ulcerative colitis and 4 Crohn’s disease data sets (
Discussion
ZO-1 was the first epithelial tight junction protein identified,24 but it is also expressed in cells that do not form tight junctions, including blastomeres at the 8-cell stage of mammalian development.25 This contrasts with some other tight junction proteins whose expression is limited to epithelial and endothelial cells and whose knockout induces only subtle abnormalities.26, 27, 28 In contrast, knockout of Tjp1, which encodes ZO-1, leads to the developmental defects as early as embryonic day
Acknowledgments
The authors thank Tiffany S. Davanzo (Slaybaugh Studios) for her beautiful illustrations and Heather Marlatt (Nationwide Histology) for her outstanding assistance with histologic staining and tissue microarray development.
Wei Ting Kuo’s current affiliation is the Graduate Institute of Oral Biology, National Taiwan University, Taipei, Taiwan. Gurminder Singh’s current affiliation is AbbVie Inc, Cambridge, Massachusetts.
CRediT Authorship Contributions
Wei-Ting Kuo, PhD (Conceptualization: Lead; Investigation: Lead; Writing –
References (37)
- et al.
Intestinal permeability and the prediction of relapse in Crohn’s disease
Lancet
(1993) - et al.
Inflammation-induced occludin downregulation limits epithelial apoptosis by suppressing caspase-3 expression
Gastroenterology
(2019) - et al.
Neutrophil transmigration in inflammatory bowel disease is associated with differential expression of epithelial intercellular junction proteins
Am J Pathol
(2001) - et al.
Interleukin-13 is the key effector Th2 cytokine in ulcerative colitis that affects epithelial tight junctions, apoptosis, and cell restitution
Gastroenterology
(2005) - et al.
The scaffolding protein ZO-1 coordinates actomyosin and epithelial apical specializations in vitro and in vivo
J Biol Chem
(2018) - et al.
The RNA polymerase III subunit Polr3b is required for the maintenance of small intestinal crypts in mice
Cell Mol Gastroenterol Hepatol
(2016) - et al.
The N and C termini of ZO-1 are surrounded by distinct proteins and functional protein networks
J Biol Chem
(2013) - et al.
Claudin-1 and claudin-5 expression patterns differentiate lung squamous cell carcinomas from adenocarcinomas
Mod Pathol
(2007) - et al.
The PDZ domains of zonula occludens-1 induce an epithelial to mesenchymal transition of Madin-Darby canine kidney I cells. Evidence for a role of β-catenin/Tcf/Lef signaling
J Biol Chem
(2000) - et al.
Increased intestinal permeability in patients with Crohn’s disease and their relatives. A possible etiologic factor
Ann Intern Med
(1986)
Increased intestinal permeability is associated with later development of Crohn’s disease
Gastroenterology
Changes in expression and distribution of claudin 2, 5 and 8 lead to discontinuous tight junctions and barrier dysfunction in active Crohn’s disease
Gut
Regional variation in gene expression in the healthy colon is dysregulated in ulcerative colitis
Gut
Graft-versus-host disease propagation depends on increased intestinal epithelial tight junction permeability
J Clin Invest
Deficiency of zonula occludens-1 causes embryonic lethal phenotype associated with defected yolk sac angiogenesis and apoptosis of embryonic cells
Mol Biol Cell
IL-22 upregulates epithelial claudin-2 to drive diarrhea and enteric pathogen clearance
Cell Host Microbe
Differentiating between tight junction-dependent and tight junction-independent intestinal barrier loss in vivo
Methods Mol Biol
ZO-1 stabilizes the tight junction solute barrier through coupling to the perijunctional cytoskeleton
Mol Biol Cell
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Conflicts of interest Guminder Singh is an employee of AbbVie, Inc. Jerrold R. Turner is a founder and shareholder of Thelium Therapeutics and has served as a consultant for Entrinsic, Immunic, and Kallyope. The remaining authors disclose no conflicts.
Funding This work was supported by National Institutes of Health grants R01DK61931 (to Jerrold R. Turner), R01DK68271 (to Jerrold R. Turner), R01DK099097 (to Clara Abraham), and P30DK034854 (to the Harvard Digestive Disease Center) and by the National Natural Science Foundation of China grants 81800464 (to Li Zuo) and 82070548 (to Li Zuo).
Author names in bold designate shared co-first authorship.
This article has an accompanying continuing medical education activity, also eligible for MOC credit, on page e18. Learning Objective: Upon completion of this CME activity, successful learners will recognize that, despite being the first tight junction protein discovered, ZO-1 is not required for tight junction barrier function. They will also be able to explain how changes in intestinal epithelial ZO-1 expression is associated with colitis, identify the two noncanonical mechanisms by which ZO-1 promotes mucosal repair, and explain the hypothesis that ZO-1 loss contributes to defective mucosal healing in inflammatory bowel disease.
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Authors share co-first authorship.