14 COLONIC EPITHELIAL CELL-SPECIFIC AFTIPHILIN KNOCKDOWN REGULATES EPITHELIAL BARRIER FUNCTION THROUGH MYOSIN LIGHT CHAIN-ASSOCIATED ACTIN ORGANIZATION IN VITRO AND INTESTINAL LENGTH IN VIVO

2020 ◽  
Vol 26 (Supplement_1) ◽  
pp. S28-S28
Author(s):  
Ivy Ka Man Law ◽  
Carl Rankin ◽  
Charalabos Pothoulakis
Keyword(s):  
Epithelial Cell ◽  
Barrier Function ◽  
Intestinal Epithelial Cell ◽  
Epithelial Barrier ◽  
Intestinal Epithelial ◽  
Knock Out ◽  
Epithelial Barrier Function ◽  
Actin Organization

Abstract Background and Aims Colonic epithelial integrity is often compromised during colonic inflammation and Inflammatory Bowel Disease. Aftiphilin (AFTPH) is a downstream target of microRNA-133a and its expression is reduced in colonic tissues of wild type mice from experimental colitis models and colonic biopsies from patients with ulcerative colitis. We have previously shown that AFTPH is involved in regulating intestinal epithelial barrier function and actin organization in human colonic epithelial cells in vitro (DDW 2016). On the other hand, our results suggested that global aftiphilin knock-out is embryonic lethal in mouse models (DDW 2019). Here, we further examined the role of AFTPH in regulating actin organization in vitro and characterize the colonic epithelial cell-specific aftiphilin knock-out mice. Methods Human colonic epithelial NCM460 cells were transfected with si-RNA against AFTPH to achieve transient AFTPH gene-silencing. Stable AFTPH knock-down clones were generated by transducing Caco2-BBE cells with recombinant lentivirus carrying sh-AFTPH or control sh-RNA. To create intestinal epithelial cell-specific aftiphilin knock-out mice, Aftph flox/flox mice were cross-bred with B6.Cg-Tg(Vil1-cre)997Gum/J mice, which express Villin-driven Cre recombinase (Vil-Cre), to generate intestinal epithelial cell-specific aftiphilin knock-out mice (Aftph Vil-/Vil-). Protein expression of F- and G-actin and p70S6K were detected using Western blot. Tissues from various organs were collected with Aftph Vil-/Vil- and its wildtype counterparts at 12 weeks. Results Results from western blot analysis showed that F-/G-actin ratio in AFTPH gene-silenced NCM460 cells were 0.6±0.17 fold, when compared to the treatment control. In addition, AFTPH gene-silencing in human colonic epithelial cells activated p70S6K, a kinase that is involved in actin organization, when compared to treatment control (1.2±0.15 vs. 2.0±0.15, p=0.0354). Furthermore, transepithelial electric resistance (TER) of Caco2-BBE cells deficient in AFTPH is significantly lower than that of control cells (0.5±0.07 fold). Lastly, in vivo intestinal epithelial cell-specific Aftph knock-out increased the length of small intestine, when compared to that of wild type mice (30.7±0.33 vs. 34.8±0.97, p=0.02), while the tissue weight of spleen to body weight was reduced (0.30±0.011 vs. 0.26±0.006, p=0.0169). Summary and Conclusions Our results indicate that AFTPH directly regulates epithelial barrier function and actin organization through mediating F-/G-actin ratio in human colonic epithelial cells, possibly through p70S6K. Importantly, intestinal epithelial cell-specific knock-out in vivo increased intestinal length and reduced size of the spleen. Our results suggested that AFTPH is crucial in regulating colonic epithelial barrier function in vitro and intestinal homeostasis.

cis 9, trans 11, but not trans 10, cis 12 CLA isomer, impairs intestinal epithelial barrier function in IPEC-J2 cells and mice through activation of GPR120-[Ca2+]i and the MLCK signaling pathway

2020 ◽  
Vol 11 (4) ◽  
pp. 3657-3667
Author(s):  
Han Su ◽  
Weijie Zhao ◽  
Fenglin Zhang ◽  
Min Song ◽  
Fangfang Liu ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Barrier Function ◽  
Epithelial Barrier ◽  
Intestinal Epithelial ◽  
Intestinal Epithelial Barrier ◽  
Epithelial Barrier Function

In vitro and in vivo studies show that c9, t11-CLA, but not t10, c12-CLA isomer, impairs intestinal epithelial barrier function in IPEC-J2 cells and mice via activation of GPR120-[Ca2+]i and the MLCK pathway.

scholarly journals Transforming Growth Factor β1 Ameliorates Intestinal Epithelial Barrier Disruption by Cryptosporidium parvum In Vitro in the Absence of Mucosal T Lymphocytes

2000 ◽  
Vol 68 (10) ◽  
pp. 5635-5644 ◽  
Author(s):  
James K. Roche ◽  
Clovis A. P. Martins ◽  
Rosana Cosme ◽  
Ronald Fayer ◽  
Richard L. Guerrant
Keyword(s):  
Epithelial Cell ◽  
Barrier Function ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β1 ◽  
Epithelial Barrier ◽  
Intestinal Epithelial ◽  
Epithelial Barrier Function ◽  
Epithelial Monolayers ◽  
Tgf Β1

ABSTRACT Exposure to oocysts of the protozoan Cryptosporidium parvum causes intestinal epithelial cell dysfunction in vivo and in vitro, but effective means by which mucosal injury might be prevented remain unclear. We examined the ability of transforming growth factor β1 (TGF-β1)—a cytokine synthesized and released by cells in the intestine—to preserve the barrier function of human colonic epithelia when challenged with C. parvum oocysts and then studied the mechanisms involved. Epithelial barrier function was monitored electrophysiologically, receptors for TGF-β1 were localized by confocal microscopy, and TGF-β1-induced protein kinase C activation was detected intracellularly by translocation of its α isozyme. TGF-β1 alone enhanced intestinal epithelial barrier function, while exposure to C. parvum oocysts (≥105/monolayer) markedly reduced barrier function to ≤40% of that of the control. When epithelial monolayers were pretreated with TGF-β1 at 5.0 ng/ml, the barrier-disrupting effect ofC. parvum oocysts was almost completely abrogated for 96 h. Further investigation showed that (i) the RI and RII receptors for TGF-β1 were present on 55 and 65% of human epithelial cell line cells, respectively, over a 1-log-unit range of receptor protein expression, as shown by flow cytometry and confirmed by confocal microscopy; (ii) only basolateral and not apical TGF-β1 exposure of the polarized epithelial monolayer resulted in a protective effect; and (iii) TGF-β1 had no direct effect on the organism in reducing its tissue-disruptive effects. In exploring mechanisms to account for the barrier-preserving effects of TGF-β1 on epithelium, we found that the protein kinase C pathway was activated, as shown by translocation of its 80-kDa α isozyme within 30 s of epithelial exposure to TGF-β1; the permeability of epithelial monolayers to passage of macromolecules was reduced by 42% with TGF-β1, even in the face of active protozoal infection; and epithelial cell necrosis monitored by lactate dehydrogenase release was decreased by 50% 70 h after oocyst exposure. Changes in epithelial function, initiated through an established set of surface receptors, likely accounts for the remarkable barrier-sparing effect of nanogram-per-milliliter concentrations of TGF-β1 when human colonic epithelium is exposed to an important human pathogen, C. parvum.

Breast Milk and Formula Feeding Affect Intestinal Epithelial Barrier Function in Vivo and in Vitro

2012 ◽  
Vol 172 (2) ◽  
pp. 302
Author(s):  
V. Poroyko ◽  
T. Mirzapoiazova ◽  
E.M. Carlisle ◽  
M.S. Caplan ◽  
J. Alverdy ◽  
...  
Keyword(s):  
Breast Milk ◽  
Barrier Function ◽  
Formula Feeding ◽  
Epithelial Barrier ◽  
Intestinal Epithelial ◽  
Intestinal Epithelial Barrier ◽  
Epithelial Barrier Function

Effects of lactoferrin on intestinal epithelial cell growth and differentiation: an in vivo and in vitro study

BioMetals ◽  
2014 ◽  
Vol 27 (5) ◽  
pp. 857-874 ◽  
Author(s):  
Anne Blais ◽  
Cuibai Fan ◽  
Thierry Voisin ◽  
Najat Aattouri ◽  
Michel Dubarry ◽  
...  
Keyword(s):  
Cell Growth ◽  
Epithelial Cell ◽  
Intestinal Epithelial Cell ◽  
In Vitro Study ◽  
Vitro Study ◽  
Intestinal Epithelial ◽  
Cell Growth And Differentiation

scholarly journals TGR5-dependent hepatoprotection through the regulation of biliary epithelium barrier function

Gut ◽  
2019 ◽  
Vol 69 (1) ◽  
pp. 146-157 ◽  
Author(s):  
Grégory Merlen ◽  
Nicolas Kahale ◽  
Jose Ursic-Bedoya ◽  
Valeska Bidault-Jourdainne ◽  
Hayat Simerabet ◽  
...  
Keyword(s):  
Liver Injury ◽  
Barrier Function ◽  
Bile Leakage ◽  
Liver Parenchyma ◽  
Knock Out ◽  
Epithelial Barrier Function ◽  
Biliary Epithelium ◽  
Duct Ligation

ObjectiveWe explored the hypothesis that TGR5, the bile acid (BA) G-protein-coupled receptor highly expressed in biliary epithelial cells, protects the liver against BA overload through the regulation of biliary epithelium permeability.DesignExperiments were performed under basal and TGR5 agonist treatment. In vitro transepithelial electric resistance (TER) and FITC-dextran diffusion were measured in different cell lines. In vivo FITC-dextran was injected in the gallbladder (GB) lumen and traced in plasma. Tight junction proteins and TGR5-induced signalling were investigated in vitro and in vivo (wild-type [WT] and TGR5-KO livers and GB). WT and TGR5-KO mice were submitted to bile duct ligation or alpha-naphtylisothiocyanate intoxication under vehicle or TGR5 agonist treatment, and liver injury was studied.ResultsIn vitro TGR5 stimulation increased TER and reduced paracellular permeability for dextran. In vivo dextran diffusion after GB injection was increased in TGR5-knock-out (KO) as compared with WT mice and decreased on TGR5 stimulation. In TGR5-KO bile ducts and GB, junctional adhesion molecule A (JAM-A) was hypophosphorylated and selectively downregulated among TJP analysed. TGR5 stimulation induced JAM-A phosphorylation and stabilisation both in vitro and in vivo, associated with protein kinase C-ζ activation. TGR5 agonist-induced TER increase as well as JAM-A protein stabilisation was dependent on JAM-A Ser285 phosphorylation. TGR5 agonist-treated mice were protected from cholestasis-induced liver injury, and this protection was significantly impaired in JAM-A-KO mice.ConclusionThe BA receptor TGR5 regulates biliary epithelial barrier function in vitro and in vivo through an impact on JAM-A expression and phosphorylation, thereby protecting liver parenchyma against bile leakage.

scholarly journals Chymase-mediated intestinal epithelial permeability is regulated by a protease-activating receptor/matrix metalloproteinase-2-dependent mechanism

2013 ◽  
Vol 304 (5) ◽  
pp. G479-G489 ◽  
Author(s):  
Katherine R. Groschwitz ◽  
David Wu ◽  
Heather Osterfeld ◽  
Richard Ahrens ◽  
Simon P. Hogan
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
Barrier Function ◽  
Epithelial Barrier ◽  
Intestinal Epithelial ◽  
Barrier Dysfunction ◽  
Intestinal Epithelial Barrier ◽  
Epithelial Barrier Function ◽  
Epithelial Barrier Dysfunction

Mast cells regulate intestinal barrier function during disease and homeostasis. Secretion of the mast cell-specific serine protease chymase regulates homeostasis. In the present study, we employ in vitro model systems to delineate the molecular pathways involved in chymase-mediated intestinal epithelial barrier dysfunction. Chymase stimulation of intestinal epithelial (Caco-2 BBe) cell monolayers induced a significant reduction in transepithelial resistance, indicating decreased intestinal epithelial barrier function. The chymase-induced intestinal epithelial barrier dysfunction was characterized by chymase-induced protease-activated receptor (PAR)-2 activation and matrix metalloproteinase (MMP)-2 expression and activation. Consistent with this observation, in vitro analysis revealed chymase-induced PAR-2 activation and increased MAPK activity and MMP-2 expression. Pharmacological and small interfering RNA-mediated antagonism of PAR-2 and MMP-2 significantly attenuated chymase-stimulated barrier dysfunction. Additionally, the chymase/MMP-2-mediated intestinal epithelial dysfunction was associated with a significant reduction in the tight junction protein claudin-5, which was partially restored by MMP-2 inhibition. Finally, incubation of Caco-2 BBe cells with chymase-sufficient, but not chymase-deficient, bone marrow-derived mast cells decreased barrier function, which was attenuated by the chymase inhibitor chymostatin. Collectively, these results suggest that mast cell/chymase-mediated intestinal epithelial barrier function is mediated by PAR-2/MMP-2-dependent pathways.

scholarly journals Deficiency in the anti-apoptotic protein DJ-1 promotes intestinal epithelial cell apoptosis and aggravates inflammatory bowel disease via p53

2020 ◽  
Vol 295 (13) ◽  
pp. 4237-4251 ◽  
Author(s):  
Jie Zhang ◽  
Min Xu ◽  
Weihua Zhou ◽  
Dejian Li ◽  
Hong Zhang ◽  
...  
Keyword(s):  
Inflammatory Bowel Disease ◽  
Epithelial Cell ◽  
Bowel Disease ◽  
Intestinal Epithelial Cell ◽  
Intestinal Inflammation ◽  
Intestinal Epithelial ◽  
P53 Expression ◽  
Inflammatory Bowel

Parkinson disease autosomal recessive, early onset 7 (PARK7 or DJ-1) is involved in multiple physiological processes and exerts anti-apoptotic effects on multiple cell types. Increased intestinal epithelial cell (IEC) apoptosis and excessive activation of the p53 signaling pathway is a hallmark of inflammatory bowel disease (IBD), which includes ulcerative colitis (UC) and Crohn's disease (CD). However, whether DJ-1 plays a role in colitis is unclear. To determine whether DJ-1 deficiency is involved in the p53 activation that results in IEC apoptosis in colitis, here we performed immunostaining, real-time PCR, and immunoblotting analyses to assess DJ-1 expression in human UC and CD samples. In the inflamed intestines of individuals with IBD, DJ-1 expression was decreased and negatively correlated with p53 expression. DJ-1 deficiency significantly aggravated colitis, evidenced by increased intestinal inflammation and exacerbated IEC apoptosis. Moreover, DJ-1 directly interacted with p53, and reduced DJ-1 levels increased p53 levels both in vivo and in vitro and were associated with decreased p53 degradation via the lysosomal pathway. We also induced experimental colitis with dextran sulfate sodium in mice and found that compared with DJ-1−/− mice, DJ-1−/−p53−/− mice have reduced apoptosis and inflammation and increased epithelial barrier integrity. Furthermore, pharmacological inhibition of p53 relieved inflammation in the DJ-1−/− mice. In conclusion, reduced DJ-1 expression promotes inflammation and IEC apoptosis via p53 in colitis, suggesting that the modulation of DJ-1 expression may be a potential therapeutic strategy for managing colitis.

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