scholarly journals TLR3 deficiency exacerbates the loss of epithelial barrier function during genital tractChlamydia muridaruminfection

2018 ◽  
Author(s):  
Ramesh Kumar ◽  
Haoli Gong ◽  
Luyao Liu ◽  
Nicole Ramos-Solis ◽  
Cheikh I. Seye ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Barrier Function ◽  
Protein Function ◽  
Genital Tract ◽  
Cell Permeability ◽  
Epithelial Barrier ◽  
Tubal Infertility ◽  
Epithelial Barrier Function ◽  
Major Cell Type ◽  
Tlr3 Signaling

AbstractProblemChlamydia trachomatisinfections are often associated with acute syndromes including cervicitis, urethritis, and endometritis, which can lead to chronic sequalae such as pelvic inflammatory disease (PID), chronic pelvic pain, ectopic pregnancy, and tubal infertility. As epithelial cells are the major cell type productively infected during genital tractChlamydiainfections, we investigated whetherChlamydiahas any impact on the integrity of the host epithelial barrier as a possible mechanism to facilitate the dissemination of infection, and examined whether TLR3 function modulates its impact.Method of StudyWe used wild-type and TLR3-deficient murine oviduct epithelial (OE) cells to ascertain whetherC. muridaruminfection had any effect on the epithelial barrier integrity of these cells as measured by transepithelial resistance (TER) and cell permeability assays. We next assessed whether infection impacted the transcription and protein function of the cellular tight-junction (TJ) genes for claudins1-4, ZO-1, JAM1 and occludin via quantitative real-time PCR (qPCR) and western blot.ResultsqPCR, immunoblotting, transwell permeability assays, and TER studies show thatChlamydiacompromises cellular TJ function throughout the course of infection in murine OE cells, and that TLR3 deficiency significantly exacerbates this effect.ConclusionOur data show that TLR3 plays a role in modulating epithelial barrier function duringChlamydiainfection of epithelial cells lining the genital tract. This proposes a role for TLR3 signaling in maintaining the integrity of epithelial barrier function during genital tractChlamydiainfection, a function that we hypothesize is important in helping limit the chlamydial spread and subsequent genital tract pathology.

scholarly journals JunD Represses Transcription and Translation of the Tight Junction Protein Zona Occludens-1 Modulating Intestinal Epithelial Barrier Function

2008 ◽  
Vol 19 (9) ◽  
pp. 3701-3712 ◽  
Author(s):  
Jie Chen ◽  
Lan Xiao ◽  
Jaladanki N. Rao ◽  
Tongtong Zou ◽  
Lan Liu ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Tight Junction ◽  
Barrier Function ◽  
Intestinal Epithelial Cells ◽  
Binding Protein ◽  
Mrna Translation ◽  
Epithelial Barrier ◽  
Intestinal Epithelial ◽  
Intestinal Epithelial Barrier ◽  
Epithelial Barrier Function

The AP-1 transcription factor JunD is highly expressed in intestinal epithelial cells, but its exact role in maintaining the integrity of intestinal epithelial barrier remains unknown. The tight junction (TJ) protein zonula occludens (ZO)-1 links the intracellular domain of TJ-transmembrane proteins occludin, claudins, and junctional adhesion molecules to many cytoplasmic proteins and the actin cytoskeleton and is crucial for assembly of the TJ complex. Here, we show that JunD negatively regulates expression of ZO-1 and is implicated in the regulation of intestinal epithelial barrier function. Increased JunD levels by ectopic overexpression of the junD gene or by depleting cellular polyamines repressed ZO-1 expression and increased epithelial paracellular permeability. JunD regulated ZO-1 expression at the levels of transcription and translation. Transcriptional repression of ZO-1 by JunD was mediated through cAMP response element-binding protein-binding site within its proximal region of the ZO-1-promoter, whereas induced JunD inhibited ZO-1 mRNA translation by enhancing the interaction of the ZO-1 3′-untranslated region with RNA-binding protein T cell-restricted intracellular antigen 1-related protein. These results indicate that JunD is a biological suppressor of ZO-1 expression in intestinal epithelial cells and plays a critical role in maintaining epithelial barrier function.

scholarly journals Chemerin Regulates Epithelial Barrier Function of Mammary Glands in Dairy Cows

Animals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 3194
Author(s):  
Yutaka Suzuki ◽  
Sachi Chiba ◽  
Koki Nishihara ◽  
Keiichi Nakajima ◽  
Akihiko Hagino ◽  
...  
Keyword(s):  
Mammary Gland ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Dairy Cows ◽  
Barrier Function ◽  
Mammary Epithelial Cells ◽  
Mammary Epithelial ◽  
Epithelial Barrier ◽  
Epithelial Tissue ◽  
Epithelial Barrier Function

Epithelial barrier function in the mammary gland acts as a forefront of the defense mechanism against mastitis, which is widespread and a major disorder in dairy production. Chemerin is a chemoattractant protein with potent antimicrobial ability, but its role in the mammary gland remains unelucidated. The aim of this study was to determine the function of chemerin in mammary epithelial tissue of dairy cows in lactation or dry-off periods. Mammary epithelial cells produced chemerin protein, and secreted chemerin was detected in milk samples. Chemerin treatment promoted the proliferation of cultured bovine mammary epithelial cells and protected the integrity of the epithelial cell layer from hydrogen peroxide (H2O2)-induced damage. Meanwhile, chemerin levels were higher in mammary tissue with mastitis. Tumor necrosis factor alpha (TNF-α) strongly upregulated the expression of the chemerin-coding gene (RARRES2) in mammary epithelial cells. Therefore, chemerin was suggested to support mammary epithelial cell growth and epithelial barrier function and to be regulated by inflammatory stimuli. Our results may indicate chemerin as a novel therapeutic target for diseases in the bovine mammary gland.

scholarly journals Differential effects of claudin-3 and claudin-4 on alveolar epithelial barrier function

2011 ◽  
Vol 301 (1) ◽  
pp. L40-L49 ◽  
Author(s):  
Leslie A. Mitchell ◽  
Christian E. Overgaard ◽  
Christina Ward ◽  
Susan S. Margulies ◽  
Michael Koval
Keyword(s):  
Epithelial Cells ◽  
Tight Junction ◽  
Barrier Function ◽  
Alveolar Epithelium ◽  
Alveolar Epithelial Cells ◽  
Epithelial Barrier ◽  
Tight Junction Proteins ◽  
Epithelial Barrier Function ◽  
Alveolar Epithelial ◽  
Junction Proteins

Alveolar barrier function depends critically on the claudin family tight junction proteins. Of the major claudins expressed by alveolar epithelial cells, claudin (Cldn)-3 and Cldn-4 are the most closely related by amino acid homology, yet they differ dramatically in the pattern of expression. Previously published reports have shown that Cldn-3 is predominantly expressed by type II alveolar epithelial cells; Cldn-4 is expressed throughout the alveolar epithelium and is specifically upregulated in response to acute lung injury. Using primary rat alveolar epithelial cells transduced with yellow fluorescent protein-tagged claudin constructs, we have identified roles for Cldn-3 and Cldn-4 in alveolar epithelial barrier function. Surprisingly, increasing expression of Cldn-3 decreased alveolar epithelial barrier function, as assessed by transepithelial resistance and dye flux measurements. Conversely, increasing Cldn-4 expression improved alveolar epithelial transepithelial resistance compared with control cells. Other alveolar epithelial tight junction proteins were largely unaffected by increased expression of Cldn-3 and Cldn-4. Taken together, these results demonstrate that, in the context of the alveolar epithelium, Cldn-3 and Cldn-4 have different effects on paracellular permeability, despite significant homology in their extracellular loop domains.

scholarly journals Inactivation of the Wnt/β-catenin signaling contributes to the epithelial barrier dysfunction induced by sodium oxalate in canine renal epithelial cells

2021 ◽  
Author(s):  
Yun Ji ◽  
Shuting Fang ◽  
Ying Yang ◽  
Zhenlong Wu
Keyword(s):  
Epithelial Cells ◽  
Barrier Function ◽  
Mdck Cells ◽  
Renal Stones ◽  
Sodium Oxalate ◽  
Epithelial Barrier ◽  
Barrier Dysfunction ◽  
Epithelial Barrier Function ◽  
Epithelial Barrier Dysfunction

Abstract Background Nephrolithiasis (also known as renal stones) is a common disease condition in companion animals, including dogs and cats. Dysfunction of renal tubular epithelial cells involves in the pathogenesis of renal stones. However, a functional role of Wnt/β-catenin signaling and its contribution to nephrolithiasis remains unknown. Results In the present study, we found that Mardin-Darby canine kidney (MDCK) cells treated with sodium oxalate resulted in reduced cell proliferation and migration, which was associated with the G0/G1 phase arrest of cell cycle progression. In addition, sodium oxalate exposure led to decreased transepithelial electrical resistance (TEER) and increased paracellular permeability. The deleterious effect of sodium oxalate on epithelial barrier function was related to decreased protein abundances of claudin-1, occludin, zonula occludens (ZO)-1, ZO-2 and ZO-3. Of note, protein levels of p-β-catenin (Ser552) in MDCK cells were repressed by sodium oxalate, indicating an inhibitory effect on the Wnt/β-catenin signaling. Intriguingly, SB216763, a GSK-3β inhibitor, enhanced the expression p-β-catenin (Ser552), and protected against epithelial barrier dysfunction in sodium oxalate-treated MDCK cells. Conclusion Taken together, our results revealed a critical role of Wnt/β-catenin signaling on the epithelial barrier function of MDCK cells. Activation of Wnt/β-catenin signaling might be an potentially therapeutic target for the treatment of renal stones in animals.

scholarly journals TLR3 deficiency exacerbates the loss of epithelial barrier function during genital tract Chlamydia muridarum infection

PLoS ONE ◽  
2019 ◽  
Vol 14 (1) ◽  
pp. e0207422 ◽  
Author(s):  
Ramesh Kumar ◽  
Haoli Gong ◽  
Luyao Liu ◽  
Nicole Ramos-Solis ◽  
Cheikh I. Seye ◽  
...  
Keyword(s):  
Barrier Function ◽  
Genital Tract ◽  
Epithelial Barrier ◽  
Epithelial Barrier Function ◽  
Chlamydia Muridarum

Farm dust extract increases the epithelial barrier function of bronchial epithelial cells

2015 ◽  
Author(s):  
Luciën E.P.M. Van der Vlugt ◽  
Katrien Eger ◽  
Gimano D. Amatngalim ◽  
Christoph Müller ◽  
Franz Bracher ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Barrier Function ◽  
Bronchial Epithelial Cells ◽  
Epithelial Barrier ◽  
Bronchial Epithelial ◽  
Epithelial Barrier Function ◽  
Dust Extract

Polyamines are necessary for synthesis and stability of occludin protein in intestinal epithelial cells

2005 ◽  
Vol 288 (6) ◽  
pp. G1159-G1169 ◽  
Author(s):  
Xin Guo ◽  
Jaladanki N. Rao ◽  
Lan Liu ◽  
Tongtong Zou ◽  
Kaspar M. Keledjian ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Tight Junction ◽  
Barrier Function ◽  
Intestinal Epithelial Cells ◽  
Integral Membrane Protein ◽  
Epithelial Barrier ◽  
Intestinal Epithelial ◽  
Tight Junction Proteins ◽  
Epithelial Barrier Function ◽  
Junction Proteins

Occludin is an integral membrane protein that forms the sealing element of tight junctions and is critical for epithelial barrier function. Polyamines are implicated in multiple signaling pathways driving different biological functions of intestinal epithelial cells (IEC). The present study determined whether polyamines are involved in expression of occludin and play a role in intestinal epithelial barrier function. Studies were conducted in stable Cdx2-transfected IEC-6 cells (IEC-Cdx2L1) associated with a highly differentiated phenotype. Polyamine depletion by α-difluoromethylornithine (DFMO) decreased levels of occludin protein but failed to affect expression of its mRNA. Other tight junction proteins, zonula occludens (ZO)-1, ZO-2, claudin-2, and claudin-3, were also decreased in polyamine-deficient cells. Decreased levels of tight junction proteins in DFMO-treated cells were associated with dysfunction of the epithelial barrier, which was overcome by exogenous polyamine spermidine. Decreased levels of occludin in polyamine-deficient cells was not due to the reduction of intracellular-free Ca2+ concentration ([Ca2+]cyt), because either increased or decreased [Ca2+]cyt did not alter levels of occludin in the presence or absence of polyamines. The level of newly synthesized occludin protein was decreased by ∼70% following polyamine depletion, whereas its protein half-life was reduced from ∼120 min in control cells to ∼75 min in polyamine-deficient cells. These findings indicate that polyamines are necessary for the synthesis and stability of occludin protein and that polyamine depletion disrupts the epithelial barrier function, at least partially, by decreasing occludin.

scholarly journals Deacidification of Cranberry Juice Reduces Its Antibacterial Properties against Oral Streptococci but Preserves Barrier Function and Attenuates the Inflammatory Response of Oral Epithelial Cells

Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1634
Author(s):  
Geneviève Pellerin ◽  
Laurent Bazinet ◽  
Daniel Grenier
Keyword(s):  
Epithelial Cells ◽  
Inflammatory Response ◽  
Barrier Function ◽  
Antibacterial Properties ◽  
Epithelial Barrier ◽  
Cranberry Juice ◽  
Potential Health ◽  
Epithelial Barrier Function ◽  
Oral Epithelial Cells ◽  
Oral Epithelial

Cranberry (Vaccinium macrocarpon) may be a potent natural adjuvant for the prevention of oral diseases due to its anti-adherence, anti-cariogenic, and anti-inflammatory properties. However, the high titrable acidity of cranberry juice (CJ) has been reported to cause gastrointestinal discomfort, leading consumers to restrict their intake of this beverage. Electrodialysis with a bipolar membrane (EDBM) can reduce the organic acid content of CJ while retaining the flavonoids associated with potential health benefits. This study aimed to assess how the deacidification of CJ by EDBM impacts the antibacterial properties of the beverage against cariogenic (Streptococcus mutans, Streptococcus sobrinus) and commensal (Streptococcus gordonii, Streptococcus oralis, Streptococcus salivarius) streptococci, and how it affects oral epithelial barrier function and inflammatory response in an in vitro model. The removal of organic acids from CJ (deacidification rate ≥42%) reduced the bactericidal activity of the beverage against planktonic S. mutans and S. gordonii after a 15-min exposure, whereas only the viability of S. gordonii was significantly impacted by CJ deacidification rate when the bacteria were embedded in a biofilm. Moreover, conditioning saliva-coated hydroxyapatite with undiluted CJ samples significantly lowered the adherence of S. mutans, S. sobrinus, and S. oralis. With respect to epithelial barrier function, exposure to CJ deacidified at a rate of ≥19% maintained the integrity of a keratinocyte monolayer over the course of 24 h compared to raw CJ, as assessed by the determination of transepithelial electrical resistance (TER) and fluorescein isothiocyanate-conjugated dextran paracellular transport. These results can be in part attributed to the inability of the deacidified CJ to disrupt two tight junction proteins, zonula occludens−1 and occludin, following exposure, unlike raw CJ. Deacidification of CJ impacted the secretion of IL-6, but not of IL-8, by oral epithelial cells. In conclusion, deacidification of CJ appears to provide benefits with respect to the maintenance of oral health.

scholarly journals In Vitro Homeostasis of Rat Oral Epithelial Cell Cultures Following Withdrawal of Periodontal Pathogens

2020 ◽  
Vol 31 (2) ◽  
pp. 135-142
Author(s):  
Ali A Abdulkareem ◽  
Hayder R Abdulbaqi ◽  
Michael R Milward
Keyword(s):  
Epithelial Cells ◽  
Barrier Function ◽  
Inflammatory Markers ◽  
Tissue Inhibitor Of Metalloproteinase ◽  
Epithelial Barrier ◽  
Oral Keratinocytes ◽  
Periodontal Pathogens ◽  
Epithelial Barrier Function ◽  
Periodontal Tissues

Abstract Inflammation of periodontal tissues is the consequence of interaction between periodontal pathogens and immune system. This is associated with increased expression of inflammatory cytokines, which may exert destructive effect to the periodontal tissues when released over long period. The aim of this study was to chronologically track the homeostasis of oral keratinocytes following removal of periodontal pathogens. This was done by investigating expression of selected inflammatory markers and integrity of epithelial monolayers in vitro. Rat oral keratinocytes were stimulated with heat-killed Fusobacterium nucleatum and Porphyromonas gingivalis over 7-days then bacteria were washed away and epithelial cells re-cultured for 3-days. Expression of IL-1β, IL-6, and IL-8 was measured by ELISA while transcription of tissue inhibitor of metalloproteinase-1 (TIMP-1) and matrix metalloproteinase -8 (MMP-8) was measured by polymerase chain reaction before and after removal of bacteria. Integrity of epithelial sheet was investigated by using transepithelial electrical resistance. Data showed general downregulation of IL-1b, IL-6, and IL-8 associated with restoring transcription of TIMP-1 and MMP-8 to normal level following removal of bacteria from epithelial cultures. However, expression of IL-8 and MMP-8 remained significantly higher than unstimulated epithelial cells despite withdrawal of F. nucleatum and P. gingivalis respectively from oral keratinocytes cultures. In addition, integrity of epithelial barrier function remained compromised even after removal of P. gingivalis. Results suggest that even after three days following removal of periodontal pathogens, oral keratinocytes sustained persistent upregulation of certain inflammatory markers that could compromise integrity of epithelial barrier function.

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