scholarly journals Thrombospondin 1 Modulates Monocyte Properties to Suppress Intestinal Mucosal Inflammation

2015 ◽  
Vol 7 (6) ◽  
pp. 601-611 ◽  
Author(s):  
Lei-Lei Fang ◽  
Hai-Qiong Yu ◽  
Rui-Jin Wu ◽  
Chong He ◽  
Meng Li ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Transforming Growth Factor ◽  
Intestinal Inflammation ◽  
Inflammatory Responses ◽  
Intestinal Epithelial Cells ◽  
Experimental Colitis ◽  
Mucosal Inflammation ◽  
Intestinal Epithelial ◽  
Thrombospondin 1 ◽  
Chronic Intestinal Inflammation

Monocytes (Mos) play an important role in the pathogenesis of intestinal mucosal inflammation. This study aims to investigate the mechanism by which the intestinal epithelial cell-derived thrombospondin 1 (TSP1) modulates Mo properties and regulates intestinal inflammatory responses. In this study, the production of TSP1 by intestinal epithelial cells was evaluated by quantitative real-time PCR and Western blotting. The properties of Mos were analyzed by flow cytometry. A mouse model of colitis was created to assess the role of epithelium-derived TSP1 in the suppression of intestinal inflammation. The results demonstrated that mouse intestinal epithelial cells (IECs) expressed TSP1, which was markedly upregulated by butyrate or feeding with Clostridium butyricum. Coculture of the butyrate-primed IECs and Mos or exposure of Mos to TSP1 in the culture induced the expression of transforming growth factor (TGF)-β in Mos. These TGF-β+ Mos had tolerogenic properties that could promote generation of inducible regulatory T cells. Adoptive transfer with TSP1-primed Mos, or feeding C. butyricum could prevent experimental colitis in mice. In summary, C. butyricum induces intestinal epithelial cells to produce TSP1 and induces TGF-β+ Mos, which further suppress experimental colitis in mice. The results implicate that the administration of C. butyricum or butyrate may have the potential to ameliorate chronic intestinal inflammation through inducing immunosuppressive Mos.

scholarly journals Unique Regulation of Enterocyte Brush Border Membrane Na-Glutamine and Na-Alanine Co-Transport by Peroxynitrite during Chronic Intestinal Inflammation

2019 ◽  
Vol 20 (6) ◽  
pp. 1504 ◽  
Author(s):  
Subha Arthur ◽  
Palanikumar Manoharan ◽  
Shanmuga Sundaram ◽  
M Rahman ◽  
Balasubramanian Palaniappan ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Brush Border ◽  
Brush Border Membrane ◽  
Intestinal Inflammation ◽  
Intestinal Epithelial Cells ◽  
Rabbit Model ◽  
Intestinal Epithelial ◽  
Mechanism Of Inhibition ◽  
Chronic Intestinal Inflammation

Na-amino acid co-transporters (NaAAcT) are uniquely affected in rabbit intestinal villus cell brush border membrane (BBM) during chronic intestinal inflammation. Specifically, Na-alanine co-transport (ASCT1) is inhibited secondary to a reduction in the affinity of the co-transporter for alanine, whereas Na-glutamine co-transport (B0AT1) is inhibited secondary to a reduction in BBM co-transporter numbers. During chronic intestinal inflammation, there is abundant production of the potent oxidant peroxynitrite (OONO). However, whether OONO mediates the unique alteration in NaAAcT in intestinal epithelial cells during chronic intestinal inflammation is unknown. In this study, ASCT1 and B0AT1 were inhibited by OONO in vitro. The mechanism of inhibition of ASCT1 by OONO was secondary to a reduction in the affinity of the co-transporter for alanine, and secondary to a reduction in the number of co-transporters for B0AT1, which were further confirmed by Western blot analyses. In conclusion, peroxynitrite inhibited both BBM ASCT1 and B0AT1 in intestinal epithelial cells but by different mechanisms. These alterations in the villus cells are similar to those seen in the rabbit model of chronic enteritis. Therefore, this study indicates that peroxynitrite may mediate the inhibition of ASCT1 and B0AT1 during inflammation, when OONO levels are known to be elevated in the mucosa.

scholarly journals Inflammation-Induced Acid Tolerance GenesgadABin Luminal Commensal Escherichia coli Attenuate Experimental Colitis

2013 ◽  
Vol 81 (10) ◽  
pp. 3662-3671 ◽  
Author(s):  
Sandrine Tchaptchet ◽  
Ting-Jia Fan ◽  
Laura Goeser ◽  
Alexi Schoenborn ◽  
Ajay S. Gulati ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Immune Responses ◽  
Intestinal Inflammation ◽  
Intestinal Epithelial Cells ◽  
Acid Tolerance ◽  
Experimental Colitis ◽  
Intestinal Epithelial ◽  
Content Type ◽  
E Coli ◽  
Chronic Intestinal Inflammation

ABSTRACTDysregulated immune responses to commensal intestinal bacteria, includingEscherichia coli, contribute to the development of inflammatory bowel diseases (IBDs) and experimental colitis. Reciprocally,E. coliresponds to chronic intestinal inflammation by upregulating expression of stress response genes, includinggadAandgadB. GadAB encode glutamate decarboxylase and protectE. colifrom the toxic effects of low pH and fermentation acids, factors present in the intestinal lumen in patients with active IBDs. We hypothesized thatE. coliupregulatesgadABduring inflammation to enhance its survival and virulence. Using real-time PCR, we determinedgadABexpression in luminalE. colifrom ex-germfree wild-type (WT) and interleukin-10 (IL-10) knockout (KO) (IL-10−/−) mice selectively colonized with a commensalE. coliisolate (NC101) that causes colitis in KO mice in isolation or in combination with 7 other commensal intestinal bacterial strains.E. colisurvival and host inflammatory responses were measured in WT and KO mice colonized with NC101 or a mutant lacking thegadABgenes (NC101ΔgadAB). The susceptibility of NC101 and NC101ΔgadABto killing by host antimicrobial peptides and their translocation across intestinal epithelial cells were evaluated using bacterial killing assays and transwell experiments, respectively. We show that expression ofgadABin luminalE. coliincreases proportionately with intestinal inflammation in KO mice and enhances the susceptibility of NC101 to killing by the host antimicrobial peptide cryptdin-4 but decreases bacterial transmigration across intestinal epithelial cells, colonic inflammation, and mucosal immune responses. Chronic intestinal inflammation upregulates acid tolerance pathways in commensalE. coliisolates, which, contrary to our original hypothesis, limits their survival and colitogenic potential. Further investigation of microbial adaptation to immune-mediated inflammation may provide novel insights into the pathogenesis and treatment of IBDs.

scholarly journals Flagellin-Dependent and -Independent Inflammatory Responses following Infection by Enteropathogenic Escherichia coli and Citrobacter rodentium

2008 ◽  
Vol 76 (4) ◽  
pp. 1410-1422 ◽  
Author(s):  
Mohammed A. Khan ◽  
Saeid Bouzari ◽  
Caixia Ma ◽  
Carrie M. Rosenberger ◽  
Kirk S. B. Bergstrom ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cells ◽  
Diarrheal Disease ◽  
Intestinal Inflammation ◽  
Inflammatory Responses ◽  
Intestinal Epithelial Cells ◽  
Mitogen Activated Protein Kinase ◽  
Dependent Manner ◽  
Intestinal Epithelial ◽  
Citrobacter Rodentium

ABSTRACT Enteropathogenic Escherichia coli (EPEC) and the murine pathogen Citrobacter rodentium belong to the attaching and effacing (A/E) family of bacterial pathogens. These noninvasive bacteria infect intestinal enterocytes using a type 3 secretion system (T3SS), leading to diarrheal disease and intestinal inflammation. While flagellin, the secreted product of the EPEC fliC gene, causes the release of interleukin 8 (IL-8) from epithelial cells, it is unclear whether A/E bacteria also trigger epithelial inflammatory responses that are FliC independent. The aims of this study were to characterize the FliC dependence or independence of epithelial inflammatory responses to direct infection by EPEC or C. rodentium. Following infection of Caco-2 intestinal epithelial cells by wild-type and ΔfliC EPEC, a rapid activation of several proinflammatory genes, including those encoding IL-8, monocyte chemoattractant protein 1, macrophage inflammatory protein 3α (MIP3α), and β-defensin 2, occurred in a FliC-dependent manner. These responses were accompanied by mitogen-activated protein kinase activation, as well as the Toll-like receptor 5 (TLR5)-dependent activation of NF-κB. At later infection time points, a subset of these proinflammatory genes (IL-8 and MIP3α) was also induced in cells infected with ΔfliC EPEC. The nonmotile A/E pathogen C. rodentium also triggered similar innate responses through a TLR5-independent but partially NF-κB-dependent mechanism. Moreover, the EPEC FliC-independent responses were increased in the absence of the locus of enterocyte effacement-encoded T3SS, suggesting that translocated bacterial effectors suppress rather than cause the FliC-independent inflammatory response. Thus, we demonstrate that infection of intestinal epithelial cells by A/E pathogens can trigger an array of proinflammatory responses from epithelial cells through both FliC-dependent and -independent pathways, expanding our understanding of the innate epithelial response to infection by these pathogens.

scholarly journals Inducible Nitric Oxide Regulates Brush Border Membrane Na-Glucose Co-transport, but Not Na:H Exchange via p38 MAP Kinase in Intestinal Epithelial Cells

Cells ◽  
2018 ◽  
Vol 7 (8) ◽  
pp. 111 ◽  
Author(s):  
Palanikumar Manoharan ◽  
Shanmuga Sundaram ◽  
Soudamani Singh ◽  
Uma Sundaram
Keyword(s):  
Nitric Oxide ◽  
Epithelial Cells ◽  
Brush Border ◽  
Brush Border Membrane ◽  
Intestinal Inflammation ◽  
Intestinal Epithelial Cells ◽  
Intestinal Epithelial ◽  
Mechanism Of Inhibition ◽  
Chronic Intestinal Inflammation ◽  
Inducible Nitric Oxide

During chronic intestinal inflammation in rabbit intestinal villus cells brush border membrane (BBM) Na-glucose co-transport (SGLT1), but not Na/H exchange (NHE3) is inhibited. The mechanism of inhibition is secondary to a decrease in the number of BBM co-transporters. In the chronic enteritis mucosa, inducible nitric oxide (iNO) and superoxide production are known to be increased and together they produce abundant peroxynitrite (OONO), a potent oxidant. However, whether OONO mediates the SGLT1 and NHE3 changes in intestinal epithelial cells during chronic intestinal inflammation is unknown. Thus, we determined the effect of OONO on SGLT1 and NHE3 in small intestinal epithelial cell (IEC-18) monolayers grown on trans well plates. In cells treated with 100 μM SIN-1 (OONO donor) for 24 h, SGLT1 was inhibited while NHE3 activity was unaltered. SIN-1 treated cells produced 40 times more OONO fluorescence compared to control cells. Uric acid (1mM) a natural scavenger of OONO prevented the OONO mediated SGLT1 inhibition. Na+/K+-ATPase which maintains the favorable trans-cellular Na gradient for Na-dependent absorptive processes was decreased by OONO. Kinetics studies demonstrated that the mechanism of inhibition of SGLT1 by OONO was secondary to reduction in the number of co-transporters (Vmax) without an alteration in the affinity. Western blot analysis showed a significant decrease in SGLT1 protein expression. Further, p38 mitogen-activated protein (MAP) kinase pathway appeared to mediate the OONO inhibition of SGLT1. Finally, at the level of the co-transporter, 3-Nitrotyrosine formation appears to be the mechanism of inhibition of SGLT1. In conclusion, peroxynitrite inhibited BBM SGLT1, but not NHE3 in intestinal epithelial cells. These changes and the mechanism of SGLT1 inhibition by OONO in IEC-18 cells is identical to that seen in villus cells during chronic enteritis. Thus, these data indicate that peroxynitrite, known to be elevated in the mucosa, may mediate the inhibition of villus cell BBM SGLT1 in vivo in the chronically inflamed intestine.

Inflammation and Inflammatory Cytokine Contribute to the Initiation and Development of Ulcerative Colitis and Its Associated Cancer

2019 ◽  
Vol 25 (10) ◽  
pp. 1595-1602 ◽  
Author(s):  
Dianbo Yao ◽  
Ming Dong ◽  
Chaoliu Dai ◽  
Shuodong Wu
Keyword(s):  
Ulcerative Colitis ◽  
Epithelial Cells ◽  
Inflammatory Cytokine ◽  
Molecular Mechanisms ◽  
Intestinal Inflammation ◽  
Inflammatory Responses ◽  
Intestinal Epithelial Cells ◽  
Bacterial Invasion ◽  
Intestinal Epithelial ◽  
Increased Risk

Abstract Dysregulated inflammatory responses play a pivotal role in the initiation, development, and progression of tumors, as demonstrated by the association between ulcerative colitis and the increased risk of colon carcinoma. In this review, the underlying mechanisms for the initiation and development of ulcerative colitis and colitis-associated cancer are described, mainly focusing on the inflammation and inflammatory cytokine. Disruption of the intestinal mucosal barrier and bacterial invasion resulted in intestinal inflammation; and further TLR4/NF-κB stimulation in intestinal epithelial cells, inflammatory cell infiltration, and inflammatory cytokine release all confer survival advantages to or promote abnormal proliferation in susceptible cells. Importantly, the respective roles of TLR4/NF-κB, TNF–α, and IL-6 in intestinal epithelial cells and inflammatory cells are summarized in detail. A thorough understanding of these molecular mechanisms may help researchers and clinicians to explore novel approaches for the prevention and treatment of colitis-associated cancer.

scholarly journals Intestinal Epithelial Cells Exposed to Bacteroides fragilis Enterotoxin Regulate NF-κB Activation and Inflammatory Responses through β-Catenin Expression

2019 ◽  
Vol 87 (11) ◽  
Author(s):  
Jong Ik Jeon ◽  
Su Hyuk Ko ◽  
Jung Mogg Kim
Keyword(s):  
Epithelial Cells ◽  
Inflammatory Responses ◽  
Intestinal Epithelial Cells ◽  
Glycogen Synthase ◽  
Bacteroides Fragilis ◽  
Mucosal Inflammation ◽  
Activator Protein 1 ◽  
Intestinal Epithelial ◽  
Content Type ◽  
Iκb Kinase

ABSTRACT The Bacteroides fragilis enterotoxin (BFT), a virulence factor of enterotoxigenic B. fragilis (ETBF), interacts with intestinal epithelial cells and can provoke signals that induce mucosal inflammation. Although β-catenin signaling is reported to be associated with inflammatory responses and BFT is known to cleave E-cadherin linked with β-catenin, little is known about the β-catenin-mediated regulation of inflammation in ETBF infection. This study was conducted to investigate the role of β-catenin as a cellular signaling intermediate in the induction of proinflammatory responses to stimulation of intestinal epithelial cells with BFT. Expression of β-catenin in intestinal epithelial cells was reduced relatively early after stimulation with BFT and then recovered to normal levels relatively late after stimulation. In contrast, phosphorylation of β-catenin in BFT-exposed cells occurred at high levels early in stimulation and decreased as time passed. Concurrently, late after stimulation the nuclear levels of β-catenin were relatively higher than those early after stimulation. Suppression of β-catenin resulted in increased NF-κB activity and interleukin-8 (IL-8) expression in BFT-stimulated cells. However, suppression or enhancement of β-catenin expression neither altered the phosphorylated IκB kinase α/β complex nor activated activator protein 1 signals. Furthermore, inhibition of glycogen synthase kinase 3β was associated with increased β-catenin expression and attenuated NF-κB activity and IL-8 expression in BFT-exposed cells. These findings suggest the negative regulation of NF-κB-mediated inflammatory responses by β-catenin in intestinal epithelial cells stimulated with BFT, resulting in attenuation of acute inflammation in ETBF infection.

scholarly journals Suppressing Syndecan-1 Shedding Ameliorates Intestinal Epithelial Inflammation through Inhibiting NF-κB Pathway and TNF-α

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Yan Zhang ◽  
Zhongqiu Wang ◽  
Jun Liu ◽  
Zhenyu Zhang ◽  
Ye Chen
Keyword(s):  
Epithelial Cells ◽  
Intestinal Inflammation ◽  
Inflammatory Responses ◽  
Intestinal Epithelial Cells ◽  
Underlying Mechanism ◽  
Intestinal Epithelial ◽  
Cell Models ◽  
Tnf Α ◽  
Epithelial Inflammation

Syndecan-1 (SDC1), with a long variable ectodomain carrying heparan sulfate chains, participates in many steps of inflammatory responses. But reports about the efforts of SDC1’s unshedding ectodomain on intestinal epithelial inflammation and the precise underlying mechanism are limited. In our study, unshedding SDC1 from intestinal epithelial cell models was established by transfecting with unshedding SDC1 plasmid into the cell, respectively. And the role of unshedding SDC1 in intestinal inflammation was further investigated. We found that components of NF-κB pathway, including P65 and IκBα, and secretion of TNF-αwere upregulated upon LPS stimulation in intestinal epithelial cells. SDC1, especially through its unshed ectodomain, significantly lessened the upregulation extent. It also functioned in inhibiting migration of neutrophils by downregulating secretion of CXCL-1. Taken together, we conclude that suppressing SDC1 shedding from intestinal epithelial cells relieves severity of intestinal inflammation by inactivating NF-κB pathway and downregulating TNF-αexpression. These results indicate that the ectodomain of SDC1 might be the optional therapy for intestinal inflammation.

scholarly journals Study on effect of anti-diarrheal medicinal plants on enteropathogenic Escherichia coli induced interleukin-8 secretion by intestinal epithelial cells

2011 ◽  
Vol 1 (1) ◽  
pp. 16 ◽  
Author(s):  
S. Brijesh ◽  
Pundarikakshudu Tetali ◽  
Tannaz J. Birdi
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cells ◽  
Medicinal Plants ◽  
Inflammatory Responses ◽  
Intestinal Epithelial Cells ◽  
Colon Adenocarcinoma ◽  
Cyperus Rotundus ◽  
Health Concern ◽  
Intestinal Epithelial ◽  
Infantile Diarrhea

Diarrhea is a major health concern in developing countries with enteropathogenic <em>Escherichia coli</em> (EPEC) being a leading cause of infantile diarrhea. Much of the pathology of EPEC infection is due to the inflammatory responses of infected intestinal epithelium through secretion of pro-inflammatory cytoki - nes such as interleukin (IL)-8. With medicinal plants gaining popularity as prospective antidiarrheal agents, we aimed to evaluate the effect of anti-diarrheal medicinal plants on secretion of IL-8 by epithelial cells in response to EPEC infection. The effect of the decoctions of four anti-diarrheal medicinal plants viz. <em>Aegle marmelos</em>, <em>Cyperus rotundus</em>, <em>Psidium guajava</em> and <em>Zingiber officinale</em> was studied on secretion of IL-8 by a human colon adenocarcinoma cell line, HT-29 infected with <em>E. coli </em>E2348/69. Two protocols were used viz. pre-incubation and post-incubation. The data obtained demonstrated that out of the four plants used, only <em>P. guajava</em> decreased secretion of IL-8 in the post-incubation protocol although in the pre-incubation protocol an increase was observed. A similar increase was seen with <em>C. rotundus</em> in the preincubation protocol. No effect on IL-8 secretion was observed with <em>A. marmelos</em> and <em>Z. officinale</em> in both protocols and with <em>C. rotundus </em>in the post-incubation protocol. The post-incubation protocol, in terms of clinical relevance, indicates the effect of the plant decoctions when used as treatment. Hence <em>P. guajava</em> may be effective in controlling the acute inflammatory response of the intestinal epithelial cells in response to EPEC infection.<p> </p>

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