title: Hedgehog signaling regulates E-cadherin expression for the maintenance of the actin cytoskeleton and tight junctions.
abstract: In the stomach, strictly regulated cell adherens junctions are crucial in determining epithelial cell differentiation. Sonic Hedgehog (Shh) regulates epithelial cell differentiation in the adult stomach. We sought to identify whether Shh plays a role in regulating adherens junction protein E-cadherin as a mechanism for epithelial cell differentiation. Mouse nontumorigenic gastric epithelial (IMGE-5) cells treated with Hedgehog signaling inhibitor cyclopamine and anti-Shh 5E1 antibody or transduced with short hairpin RNA against Skinny Hedgehog (IMGE-5(Ski)) were cultured. A mouse model expressing a parietal cell-specific deletion of Shh (HKCre/Shh(KO)) was used to identify further changes in adherens and tight junctions. Inhibition of Hedgehog signaling in IMGE-5 cells caused loss of E-cadherin expression accompanied by disruption of F-actin cortical expression and relocalization of zonula occludens-1 (ZO-1). Loss of E-cadherin was also associated with increased proliferation in IMGE-5(Ski) cells and increased expression of the mucous neck cell lineage marker MUC6. Compared with membrane-expressed E-cadherin and ZO-1 protein in controls, dissociation of E-cadherin/β-catenin and ZO-1/occludin protein complexes was observed in HKCre/Shh(KO) mice. In conclusion, we demonstrate that Hedgehog signaling regulates E-cadherin expression that is required for the maintenance of F-actin cortical expression and stability of tight junction protein ZO-1.
authors.affiliation: Department of Molecular and Cellular Physiology, Univ. of Cincinnati College of Medicine, OH 45267-0576, USA.
authors.forename: Chang
authors.initials: C
authors.lastname: Xiao
authors.forename: Sally A
authors.initials: SA
authors.lastname: Ogle
authors.forename: Michael A
authors.initials: MA
authors.lastname: Schumacher
authors.forename: Neal
authors.initials: N
authors.lastname: Schilling
authors.forename: Robert A
authors.initials: RA
authors.lastname: Tokhunts
authors.forename: Melissa A
authors.initials: MA
authors.lastname: Orr-Asman
authors.forename: Marian L
authors.initials: ML
authors.lastname: Miller
authors.forename: David J
authors.initials: DJ
authors.lastname: Robbins
authors.forename: Frederic
authors.initials: F
authors.lastname: Hollande
authors.forename: Yana
authors.initials: Y
authors.lastname: Zavros
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D000911:Antibodies, Monoclonal; D015820:Cadherins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D003599:Cytoskeleton / Q000502:physiology*; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology; D053823:Hedgehog Proteins / Q000235:genetics / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism; D021381:Protein Transport / Q000502:physiology; D034741:RNA, Small Interfering; D015398:Signal Transduction / Q000187:drug effects* / Q000502:physiology*; D019108:Tight Junctions / Q000502:physiology*; D014704:Veratrum Alkaloids / Q000494:pharmacology; D062826:Zonula Occludens-1 Protein
chemical_list: D000199:Actins; D000911:Antibodies, Monoclonal; D015820:Cadherins; D053823:Hedgehog Proteins; D008565:Membrane Proteins; D010750:Phosphoproteins; D034741:RNA, Small Interfering; C569043:Tjp1 protein, mouse; D014704:Veratrum Alkaloids; D062826:Zonula Occludens-1 Protein; C000541:cyclopamine