scholarly journals The Roles of Tricellular Tight Junction Protein Angulin-1/Lipolysis-Stimulated Lipoprotein Receptor (LSR) in Endometriosis and Endometrioid-Endometrial Carcinoma

Cancers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 6341
Author(s):  
Hiroshi Shimada ◽  
Takayuki Kohno ◽  
Takumi Konno ◽  
Tadahi Okada ◽  
Kimihito Saito ◽  
...  
Keyword(s):  
Tight Junction ◽  
Endometrial Carcinoma ◽  
P53 Protein ◽  
Control Cell ◽  
Lipoprotein Receptor ◽  
Tight Junction Proteins ◽  
Mesenchymal Transition ◽  
Junction Protein ◽  
Endometrioid Endometrial Carcinoma ◽  
Junction Proteins

Tight junction proteins play roles beyond permeability barriers functions and control cell proliferation and differentiation. The relation between tight junctions and the signal transduction pathways affects cell growth, invasion and migration. Abnormality of tight junction proteins closely contributes to epithelial mesenchymal transition (EMT) and malignancy of various cancers. Angulin-1/lipolysis-stimulated lipoprotein receptor (LSR) forms tricellular contacts that has a barrier function. Downregulation of angulin-1/LSR correlates with the malignancy in various cancers, including endometrioid-endometrial carcinoma (EEC). These alterations have been shown to link to not only multiple signaling pathways such as Hippo/YAP, HDAC, AMPK, but also cell metabolism in ECC cell line Sawano. Moreover, loss of angulin-1/LSR upregulates claudin-1, and loss of apoptosis stimulating p53 protein 2 (ASPP2) downregulates angulin-1/LSR. Angulin-1/LSR and ASPP2 concentrate at both midbody and centrosome in cytokinesis. In EEC tissues, angulin-1/LSR and ASPP2 are reduced and claudin-2 is overexpressed during malignancy, while in the tissues of endometriosis changes in localization of angulin-1/LSR and claudin-2 are seen. This review highlights how downregulation of angulin-1/LSR promotes development of endometriosis and EEC and discusses about the roles of angulin-1/LSR and its related proteins, including claudins and ASPP2.

scholarly journals Regulation of testicular tight junctions by gonadotrophins in the adult Djungarian hamster in vivo

Reproduction ◽  
2008 ◽  
Vol 135 (6) ◽  
pp. 867-877 ◽  
Author(s):  
Gerard A Tarulli ◽  
Sarah J Meachem ◽  
Stefan Schlatt ◽  
Peter G Stanton
Keyword(s):  
Tight Junction ◽  
Adaptor Protein ◽  
Tight Junction Protein ◽  
Mrna Levels ◽  
Tight Junction Proteins ◽  
Djungarian Hamster ◽  
Junction Protein ◽  
Protein Localisation ◽  
Junction Proteins

This study aimed to assess the effect of gonadotrophin suppression and FSH replacement on testicular tight junction dynamics and blood–testis barrier (BTB) organisation in vivo, utilising the seasonal breeding Djungarian hamster. Confocal immunohistology was used to assess the cellular organisation of tight junction proteins and real-time PCR to quantify tight junction mRNA. The effect of tight junction protein organisation on the BTB permeability was also investigated using a biotin-linked tracer. Tight junction protein (claudin-3, junctional adhesion molecule (JAM)-A and occludin) localisation was present but disorganised after gonadotrophin suppression, while mRNA levels (claudin-11, claudin-3 and occludin) were significantly (two- to threefold) increased. By contrast, both protein localisation and mRNA levels for the adaptor protein zona occludens-1 decreased after gonadotrophin suppression. FSH replacement induced a rapid reorganisation of tight junction protein localisation. The functionality of the BTB (as inferred by biotin tracer permeation) was found to be strongly associated with the organisation and localisation of claudin-11. Surprisingly, JAM-A was also recognised on spermatogonia, suggesting an additional novel role for this protein in trans-epithelial migration of germ cells across the BTB. It is concluded that gonadotrophin regulation of tight junction proteins forming the BTB occurs primarily at the level of protein organisation and not gene transcription in this species, and that immunolocalisation of the organised tight junction protein claudin-11 correlates with BTB functionality.

scholarly journals Junctional Adhesion Molecule-A Is Critical for the Formation of Pseudocanaliculi and Modulates E-cadherin Expression in Hepatic Cells

2007 ◽  
Vol 282 (38) ◽  
pp. 28137-28148 ◽  
Author(s):  
Genevieve Konopka ◽  
Jackie Tekiela ◽  
Moriah Iverson ◽  
Clive Wells ◽  
Stephen A. Duncan
Keyword(s):  
Tight Junction ◽  
Adhesion Molecule ◽  
Cell Morphology ◽  
Adherens Junction ◽  
Tight Junction Proteins ◽  
Hepatic Cells ◽  
Junction Protein ◽  
Striking Change ◽  
Junction Proteins ◽  
E Cadherin

Hepatocytes are polarized epithelial cells whose function depends upon their ability to distinguish between the apical and basolateral surfaces that are located at intercellular tight junctions. It has been proposed that the signaling cascades originating at these junctions influence cellular activity by controlling gene expression in the cell nucleus. To assess the validity of this proposal with regard to hepatocytes, we depleted expression of the tight junction protein junctional adhesion molecule-A (JAM-A) in the HepG2 human hepatocellular carcinoma cell line. Reduction of JAM-A resulted in a striking change in cell morphology, with cells forming sheets 1-2 cells thick instead of the normal multilayered clusters. In the absence of JAM-A, other tight junction proteins were mislocalized, and pseudocanaliculi, which form the apical face of the hepatocyte, were consequently absent. There was a strong transcriptional induction of the adherens junction protein E-cadherin in cells with reduced levels of JAM-A. This increase in E-cadherin was partially responsible for the observed alterations in cell morphology and mislocalization of tight junction proteins. We therefore propose the existence of a novel mechanism of cross-talk between specific components of tight and adherens junctions that can be utilized to regulate adhesion between hepatic cells.

scholarly journals Role of Tricellular Tight Junction Protein Lipolysis-Stimulated Lipoprotein Receptor (LSR) in Cancer Cells

2019 ◽  
Vol 20 (14) ◽  
pp. 3555 ◽  
Author(s):  
Takayuki Kohno ◽  
Takumi Konno ◽  
Takashi Kojima
Keyword(s):  
Tight Junction ◽  
Cancer Progression ◽  
Epithelial Barrier ◽  
Dependent Manner ◽  
Tight Junction Proteins ◽  
Barrier Dysfunction ◽  
Endometrial Cells ◽  
Functional Changes ◽  
Junction Protein ◽  
Junction Proteins

Maintaining a robust epithelial barrier requires the accumulation of tight junction proteins, LSR/angulin-1 and tricellulin, at the tricellular contacts. Alterations in the localization of these proteins temporarily cause epithelial barrier dysfunction, which is closely associated with not only physiological differentiation but also cancer progression and metastasis. In normal human endometrial tissues, the endometrial cells undergo repeated proliferation and differentiation under physiological conditions. Recent observations have revealed that the localization and expression of LSR/angulin-1 and tricellulin are altered in a menstrual cycle-dependent manner. Moreover, it has been shown that endometrial cancer progression affects these alterations. This review highlights the differences in the localization and expression of tight junction proteins in normal endometrial cells and endometrial cancers and how they cause functional changes in cells.

Faecal Proteases from Pouchitis Patients Activate Protease Activating Receptor-2 to Disrupt the Epithelial Barrier

2019 ◽  
Vol 13 (12) ◽  
pp. 1558-1568 ◽  
Author(s):  
Sarit Hoffman ◽  
Nathaniel Aviv Cohen ◽  
Ian M Carroll ◽  
Hagit Tulchinsky ◽  
Ilya Borovok ◽  
...  
Keyword(s):  
Tight Junction ◽  
Proteolytic Activity ◽  
Epithelial Barrier ◽  
Dependent Manner ◽  
Epithelial Permeability ◽  
Tight Junction Proteins ◽  
Microbial Composition ◽  
Junction Protein ◽  
Activating Receptor ◽  
Junction Proteins

Abstract Background and Aims The pathogenesis of pouch inflammation may involve epithelial barrier disruption. We investigated whether faecal proteolytic activity is increased during pouchitis and results in epithelial barrier dysfunction through protease activating receptor [PAR] activation, and assessed whether the intestinal microbiome may be the source of the proteases. Methods Faecal samples were measured for protease activity using a fluorescein isothiocyanate [FITC]-casein florescence assay. Caco-2 cell monolayers were exposed to faecal supernatants to assess permeability to FITC-dextran. Tight junction protein integrity and PAR activation were assessed by immunoblot and immunofluorescence. A truncated PAR2 protein in Caco-2 cells was achieved by stable transfection using CRISPR/Cas9 plasmid. PAR2 activation in pouch biopsies was examined using antibodies directed to the N-terminus of the protein. Microbial composition was analysed based on 16S rRNA gene sequence analysis. Results Ten pouchitis patients, six normal pouch [NP] patients and nine healthy controls [HC] were recruited. The pouchitis patients exhibited a 5.19- and 5.35-fold higher faecal protease [FP] activity [p ≤ 0.05] compared to the NP and HC participants, respectively. The genus Haemophilus was positively associated with FP activity [R = 0.718, false discovery rate < 0.1]. Faecal supernatants from pouchitis patients activated PAR2 on Caco-2 monolayers, disrupted tight junction proteins and increased epithelial permeability. PAR2 truncation in Caco-2 abrogated faecal protease-mediated permeability. Pouch biopsies obtained from pouchitis patients, but not from NP patients, displayed PAR2 activation. Conclusions Protease-producing bacteria may increase faecal proteolytic activity that results in pouch inflammation through disruption of tight junction proteins and increased epithelial permeability in a PAR2-dependent manner. This mechanism may initiate or propagate pouch inflammation.

Annexin A2 heterotetramer: role in tight junction assembly

2004 ◽  
Vol 287 (3) ◽  
pp. F481-F491 ◽  
Author(s):  
David B. N. Lee ◽  
Nora Jamgotchian ◽  
Suni G. Allen ◽  
Frederick W. K. Kan ◽  
Irene L. Hale
Keyword(s):  
Tight Junction ◽  
Lipid Bilayers ◽  
Microscopic Analysis ◽  
Annexin A2 ◽  
Tight Junction Proteins ◽  
Two Dimensional Gel Electrophoresis ◽  
Calcium Chelation ◽  
Junction Protein ◽  
Bona Fide ◽  
Junction Proteins

The tight junction has been characterized as a domain of focal fusions of the exoplasmic leaflets of the lipid bilayers from adjacent epithelial cells. Approximating membranes to within fusion distance is a thermodynamically unfavorable process and requires the participation of membrane-bridging or -fusion proteins. No known tight junction protein exhibits such activities. Annexin A2 (A2), in particular its heterotetramer (A2t), is known to form junctions between lipid bilayer structures through molecular bridging of their external leaflets. We demonstrate abundant A2 expression in Madin-Darby canine kidney II monolayers by two-dimensional gel electrophoresis. Confocal immunofluorescence microscopic analysis suggests the bulk of A2 is located along the apical and lateral plasma membrane in its tetrameric configuration, consisting of two A2 and two p11 (an 11-kDa calmodulin-related protein, S100A10) subunits. Immunocytochemistry and ultrastructural immunogold labeling demonstrate colocalization of the A2 subunit with bona fide tight junction proteins, zonula occludens-1, occludin, and claudin-1, at cell-cell contacts. The extracellular addition of a synthetic peptide, targeted to disrupt the binding between A2 and p11, completely aborts tight junction assembly in calcium chelation studies. We propose A2t as a member of a new class of tight junction proteins responsible for the long-observed convergence of adjacent exoplasmic lipid leaflets in tight junction assembly.

scholarly journals Lactobacillus plantarum inhibits intestinal epithelial barrier dysfunction induced by unconjugated bilirubin

2010 ◽  
Vol 104 (3) ◽  
pp. 390-401 ◽  
Author(s):  
Yukun Zhou ◽  
Huanlong Qin ◽  
Ming Zhang ◽  
Tongyi Shen ◽  
Hongqi Chen ◽  
...  
Keyword(s):  
Tight Junction ◽  
Lactobacillus Plantarum ◽  
Laser Scanning Microscopy ◽  
Unconjugated Bilirubin ◽  
Epithelial Barrier ◽  
Intestinal Epithelial ◽  
Tight Junction Proteins ◽  
Intestinal Epithelial Barrier ◽  
Junction Protein ◽  
Junction Proteins

Although a large number of in vitro and in vivo tests have confirmed that taking probiotics can improve the intestinal barrier, few studies have focused on the relationship between probiotics and the intestinal epithelial barrier in hyperbilirubinaemia. To investigate the effects of and mechanisms associated with probiotic bacteria (Lactobacillus plantarum; LP) and unconjugated bilirubin (UCB) on the intestinal epithelial barrier, we measured the viability, apoptotic ratio and protein kinase C (PKC) activity of Caco-2 cells. We also determined the distribution and expression of tight junction proteins such as occludin, zonula occludens (ZO)-1, claudin-1, claudin-4, junctional adhesion molecule (JAM)-1 and F-actin using confocal laser scanning microscopy, immunohistochemistry, Western blotting and real-time quantitative PCR. The present study demonstrated that high concentrations of UCB caused obvious cytotoxicity and decreased the transepithelial electrical resistance (TER) of the Caco-2 cell monolayer. Low concentrations of UCB inhibited the expression of tight junction proteins and PKC but could induce UDP-glucuronosyltransferases 1 family-polypeptide A1 (UGT1A1) expression. UCB alone caused decreased PKC activity, serine phosphorylated occludin and ZO-1 levels. After treatment with LP, the effects of UCB on TER and apoptosis were mitigated; LP also prevented aberrant expression and rearrangement of tight junction proteins. Moreover, PKC activity and serine phosphorylated tight junction protein levels were partially restored after treatment with LP, LP exerted a protective effect against UCB damage to Caco-2 monolayer cells, and it restored the structure and distribution of tight junction proteins by activating the PKC pathway. In addition, UGT1A1 expression induced by UCB in Caco-2 cells could ameliorate the cytotoxicity of UCB.

scholarly journals Tricellular Tight Junction Protein Tricellulin Is Targeted by the Enteropathogenic Escherichia coli Effector EspG1, Leading to Epithelial Barrier Disruption

2016 ◽  
Vol 85 (1) ◽  
Author(s):  
Vijay Morampudi ◽  
Franziska A. Graef ◽  
Martin Stahl ◽  
Udit Dalwadi ◽  
Victoria S. Conlin ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Tight Junction ◽  
Significant Loss ◽  
Effector Proteins ◽  
Epithelial Barrier ◽  
Tight Junction Proteins ◽  
Barrier Dysfunction ◽  
Barrier Disruption ◽  
Junction Protein ◽  
Junction Proteins

ABSTRACT Enteropathogenic Escherichia coli (EPEC)-induced diarrhea is often associated with disruption of intestinal epithelial tight junctions. Although studies have shown alterations in the expression and localization of bicellular tight junction proteins during EPEC infections, little is known about whether tricellular tight junction proteins (tTJs) are affected. Using Caco-2 cell monolayers, we investigated if EPEC is capable of targeting the tTJ protein tricellulin. Our results demonstrated that at 4 h postinfection, EPEC induced a significant reduction in tricellulin levels, accompanied by a significant loss of transepithelial resistance (TEER) and a corresponding increase in paracellular permeability. Conversely, cells overexpressing tricellulin were highly resistant to EPEC-induced barrier disruption. Confocal microscopy revealed the distribution of tricellulin into the plasma membrane of infected epithelial cells and confirmed the localization of EPEC aggregates in close proximity to tTJs. Moreover, infections with EPEC strains lacking genes encoding specific type III secreted effector proteins demonstrated a crucial role for the effector EspG1 in modulating tricellulin expression. Complementation studies suggest that the EspG-induced depletion of tricellulin is microtubule dependent. Overall, our results show that EPEC-induced epithelial barrier dysfunction is mediated in part by EspG1-induced microtubule-dependent depletion of tricellulin.

scholarly journals MTOR PROMOTES BBB BREAKDOWN IN A MODEL OF ALZHEIMER’S DISEASE

2019 ◽  
Vol 3 (Supplement_1) ◽  
pp. S256-S256 ◽  
Author(s):  
Stephen F Hernandez ◽  
Candice E Van Skike ◽  
Nick DeRosa ◽  
Veronica Galvan
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Mouse Model ◽  
Tight Junction ◽  
Tg2576 Mouse ◽  
Tight Junction Proteins ◽  
Study Results ◽  
Junction Protein ◽  
Tg2576 Mice ◽  
Junction Proteins

Abstract Cerebral amyloid angiopathy (CAA) is characterized by fibrillar amyloid β (Aβ) association with cerebrovasculature, which leads to impaired brain vascular function, and is present in 87% of people with Alzheimer’s disease (AD). We previously showed that inhibition of mTOR by rapamycin prevented BBB breakdown and reduced vascular fibrillar Aβ in 18-19 month old Tg2576 mice that model AD-associated CAA. This finding suggests that mTOR attenuation restores integrity of the blood brain barrier (BBB) and concomitantly reduces vascular Aβ accumulation in this mouse model. Objective: To determine the mechanisms by which mTOR drives BBB breakdown we measured the abundance of tight junction proteins zonula occludens 1 (ZO-1), occludin, and claudin-5. Methods: We used immunofluorescent confocal microscopy on frozen brain tissue sections of the same Tg2576 mice used in the previous study. Results: We confirm BBB breakdown in Tg2576 mouse brains and showed that some, but not all tight junction proteins measured were decreased in cerebrovasculature of Tg2576 mice. Attenuation of mTOR by rapamycin preserved BBB integrity, decreased vascular Aβ accumulation, and increased levels of tight junction protein abundance in Tg2576 mice, which also showed a reduced numbers of cerebral microhemorrhages. Conclusions: Taken together, these data suggest that mTOR promotes brain vascular Aβ deposition, BBB breakdown and vascular damage in the Tg2576 mouse model. Thus, mTOR inhibitors such as rapamycin – an FDA approved drug - may have promise in the treatment of AD and other dementias with related cerebrovascular dysfunction.

scholarly journals Dendrobium chrysotoxumLindl. Alleviates Diabetic Retinopathy by Preventing Retinal Inflammation and Tight Junction Protein Decrease

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Zengyang Yu ◽  
Chenyuan Gong ◽  
Bin Lu ◽  
Li Yang ◽  
Yuchen Sheng ◽  
...  
Keyword(s):  
Diabetic Retinopathy ◽  
Tight Junction ◽  
Diabetic Rats ◽  
Intercellular Adhesion Molecule ◽  
Tight Junction Proteins ◽  
Intercellular Adhesion Molecule 1 ◽  
Traditional Chinese Herbal Medicine ◽  
Junction Protein ◽  
Retinal Inflammation ◽  
Junction Proteins

Diabetic retinopathy (DR) is a serious complication of diabetes mellitus. This study aimed to observe the alleviation of the ethanol extract ofDendrobium chrysotoxumLindl. (DC), a traditional Chinese herbal medicine, on DR and its engaged mechanism. After DC (30 or 300 mg/kg) was orally administrated, the breakdown of blood retinal barrier (BRB) in streptozotocin- (STZ-) induced diabetic rats was attenuated by DC. Decreased retinal mRNA expression of tight junction proteins (including occludin and claudin-1) in diabetic rats was also reversed by DC. Western blot analysis and retinal immunofluorescence staining results further confirmed that DC reversed the decreased expression of occludin and claudin-1 proteins in diabetic rats. DC reduced the increased retinal mRNA expressions of intercellular adhesion molecule-1 (ICAM-1), tumor necrosis factorα(TNFα), interleukin- (IL-) 6, and IL-1βin diabetic rats. In addition, DC alleviated the increased 1 and phosphorylated p65, IκB, and IκB kinase (IKK) in diabetic rats. DC also reduced the increased serum levels of TNFα, interferon-γ(IFN-γ), IL-6, IL-1β, IL-8, IL-12, IL-2, IL-3, and IL-10 in diabetic rats. Therefore, DC can alleviate DR by inhibiting retinal inflammation and preventing the decrease of tight junction proteins, such as occludin and claudin-1.

scholarly journals The serine protease-mediated increase in intestinal epithelial barrier function is dependent on occludin and requires an intact tight junction

2016 ◽  
Vol 311 (3) ◽  
pp. G466-G479 ◽  
Author(s):  
Natalie J. Ronaghan ◽  
Judie Shang ◽  
Vadim Iablokov ◽  
Raza Zaheer ◽  
Pina Colarusso ◽  
...  
Keyword(s):  
Epithelial Cell ◽  
Tight Junction ◽  
Serine Protease ◽  
Barrier Function ◽  
Serine Proteases ◽  
Cell Fractionation ◽  
Intestinal Epithelial ◽  
Tight Junction Proteins ◽  
Junction Protein ◽  
Junction Proteins

Barrier dysfunction is a characteristic of the inflammatory bowel diseases (IBD), Crohn's disease and ulcerative colitis. Understanding how the tight junction is modified to maintain barrier function may provide avenues for treatment of IBD. We have previously shown that the apical addition of serine proteases to intestinal epithelial cell lines causes a rapid and sustained increase in transepithelial electrical resistance (TER), but the mechanisms are unknown. We hypothesized that serine proteases increase barrier function through trafficking and insertion of tight junction proteins into the membrane, and this could enhance recovery of a disrupted monolayer after calcium switch or cytokine treatment. In the canine epithelial cell line, SCBN, we showed that matriptase, an endogenous serine protease, could potently increase TER. Using detergent solubility-based cell fractionation, we found that neither trypsin nor matriptase treatment changed levels of tight junction proteins at the membrane. In a fast calcium switch assay, serine proteases did not enhance the rate of recovery of the junction. In addition, serine proteases could not reverse barrier disruption induced by IFNγ and TNFα. We knocked down occludin in our cells using siRNA and found this prevented the serine protease-induced increase in TER. Using fluorescence recovery after photobleaching (FRAP), we found serine proteases induce a greater mobile fraction of occludin in the membrane. These data suggest that a functional tight junction is needed for serine proteases to have an effect on TER, and that occludin is a crucial tight junction protein in this mechanism.

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