Nuclear factor-κB activation promotes restitution of wounded intestinal epithelial monolayers

2003 ◽  
Vol 285 (5) ◽  
pp. C1028-C1035 ◽  
Author(s):  
Laurence J. Egan ◽  
Ana de Lecea ◽  
Evan D. Lehrman ◽  
Gennett M. Myhre ◽  
Lars Eckmann ◽  
...  
Keyword(s):  
Cell Migration ◽  
Intestinal Inflammation ◽  
Healing Process ◽  
Growth Factor Receptor ◽  
Nuclear Factor ◽  
Intestinal Epithelial ◽  
Wound Edge ◽  
Epithelial Restitution

Epithelial restitution, the movement of wound-edge cells into an area of epithelial cell denudation, is an important early step in the ulcer healing process. Growth factors regulate epithelial restitution, yet little is known about the transcriptional pathways that mediate their effects on cell migration. The transcription factor nuclear factor (NF)-κB is a master regulator of the host inflammatory response that is activated in the epithelium in intestinal inflammation, which often accompanies epithelial injury. We hypothesized that NF-κB may be an important transcriptional regulator of epithelial restitution. In an in vitro model of scrape-wounded monolayers of nontransformed rat intestinal epithelial (RIE-1) cells, NF-κB was activated in epithelial cells at the wound edge. Blocking of NF-κB activation by either pharmacological or genetic approaches inhibited intestinal epithelial restitution. Moreover, scrape wounding activated the epidermal growth factor receptor (EGFR) in cells at the wound edge, and, importantly, inhibiting EGFR tyrosine kinase activity decreased scrape wound-induced NF-κB activation and cell migration. These results indicate a novel role of NF-κB activation in a signaling pathway important for restitution and healing of intestinal epithelia. To the extent NF-κB may have parallel functions in vivo, they also suggest a need for caution in the proposed use of NF-κB inhibitors for the treatment of conditions associated with inflammation and injury of intestinal and other mucosal surfaces.

7 LACTOBACILLUS REUTERI SUPPRESSES PRO-INFLAMMATORY DRIVEN REACTIVE OXYGEN SPECIES IN VITRO IN HUMAN INTESTINAL EPITHELIAL CELLS AND IN VIVO IN A TNBS COLITIS MOUSE MODEL

2020 ◽  
Vol 26 (Supplement_1) ◽  
pp. S41-S41 ◽  
Author(s):  
Wenly Ruan ◽  
Melinda Engevik ◽  
Alexandra Chang-Graham ◽  
Joseph Hyser ◽  
James Versalovic
Keyword(s):  
Reactive Oxygen Species ◽  
Epithelial Cells ◽  
Lactobacillus Reuteri ◽  
Intestinal Inflammation ◽  
Intestinal Epithelial Cells ◽  
Oxygen Species ◽  
Intestinal Epithelial ◽  
Colitis Model

Abstract Background Reactive oxygen species (ROS) play a role in maintaining intestinal epithelial homeostasis and are normally kept at low levels via antioxidant compounds. Dysregulation of ROS can lead to intestinal inflammation and contribute to inflammatory bowel disease (IBD). Select gut microbes possess the enzymatic machinery to produce antioxidants whereas others can dysregulate levels of ROS. Our model microbe, Lactobacillus reuteri (ATCC PTA 6475), has been demonstrated to reduce intestinal inflammation in mice models. It contains the genes encoding two distinct GshA-like glutamylcysteine ligases. We hypothesize that L. reuteri can secrete γ-glutamylcysteine to suppress ROS, minimize NFκB activation and regulate secretion of e pithelial cytokines. Methods & Results Conditioned media from L. reuteri was analyzed via mass spectrometry to confirm the presence of γ-glutamylcysteine. All cysteine containing products including γ-glutamylcysteine were fluorescently tagged in the conditioned media and then incubated with HT29 cell monolayers as well as human jejunal enteroid (HJE) monolayers. γ-glutamylcysteine was demonstrated to enter intestinal epithelial cells based on microscopy. Next, a Thioltracker assay was used to show increased intracellular glutathione levels by L. reuteri secreted γ-glutamylcysteine. HT29 cells and HJEs were then treated with IL-1β or hydrogen peroxide, and L. reuteri metabolites as well as γ-glutamylcysteine significantly suppressed pro-inflammatory cytokine driven ROS and IL-8 production. L. reuteri secreted products also reduced activity of NFκB as determined by a luciferase reporter assay. γ-glutamylcysteine deficient mutants were generated by targeted mutagenesis of GshA genes, and these mutant L. reuteri strains had a diminished ability to suppress IL-8 production and ROS. To further test the role of L. reuteri secreted γ-glutamylcysteine in vivo, a 2,4,6-Trinitrobenzenesulfonic acid (TNBS)- induced mouse colitis model was used. Adolescent mice were orogavaged with PBS, L. reuteri, L. reuteri GshA2 mutant, or γ-glutamylcysteine for a week after which TNBS was rectally administered to induce colitis. We demonstrate that L. reuteri and γ-glutamylcysteine can suppress histologic inflammation compared to PBS control and L. reuteri GshA2 mutant groups. Conclusions Together these data indicate that L. reuteri secretes γ-glutamylcysteine which can enter the intestinal epithelial cells and modulate epithelial cytokine production. It acts via suppression of ROS and NFκB which then decreases IL-8 production. We are able to demonstrate this in vitro in both HT 29 cells and HJEs. We now also demonstrate this in vivo in a mouse colitis model. These experiments highlight a prominent role for ROS intermediates in microbiome-mammalian cell signaling processes involved in immune responses and intestinal inflammation.

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.

scholarly journals RETRACTED ARTICLE:Deficiency in intestinal epithelial Reg4 ameliorates intestinal inflammation and alters the colonic bacterial composition

2019 ◽  
Vol 12 (4) ◽  
pp. 919-929 ◽  
Author(s):  
Yongtao Xiao ◽  
Ying Lu ◽  
Ying Wang ◽  
Weihui Yan ◽  
Wei Cai
Keyword(s):  
Intestinal Inflammation ◽  
Elevated Serum ◽  
Intestinal Failure ◽  
Experimental Colitis ◽  
Mucosal Injury ◽  
Intestinal Epithelial ◽  
Bacterial Composition ◽  
Novel Target

AbstractThe regenerating islet-derived family member 4 (Reg4) in the gastrointestinal tract is up-regulated during intestinal inflammation. However, the physiological function of Reg4 in the inflammation is largely unknown. In the current study, the functional roles and involved mechanisms of intestinal epithelial Reg4 in intestinal inflammation were studied in healthy and inflamed states using human intestinal specimens, an intestinal conditional Reg4 knockout mouse (Reg4ΔIEC) model and dextran sulfate sodium (DSS)-induced colitis model. We showed that the elevated serum Reg4 in pediatric intestinal failure (IF) patients were positively correlated with the serum concentrations of proinflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). In inflamed intestine of IF patients, the crypt base Reg4 protein was increased and highly expressed towards the luminal face. The Reg4 was indicated as a novel target of activating transcription factor 2 (ATF2) that enhanced Reg4 expression during the intestinal inflammation. In vivo, the DSS-induced colitis was significantly ameliorated in Reg4ΔIEC mice. Reg4ΔIEC mice altered the colonic bacterial composition and reduced the bacteria adhere to the colonic epithelium. In vitro, Reg4 was showed to promote the growth of colonic organoids, and that this occurs through a mechanism involving activation of signal transducer and activator of transcription 3 (STAT3). In conclusion, our findings demonstrated intestinal-epithelial Reg4 deficiency protects against experimental colitis and mucosal injury via a mechanism involving alteration of bacterial homeostasis and STAT3 activation.

scholarly journals Schisandrin A protects intestinal epithelial cells from deoxynivalenol-induced cytotoxicity, oxidative damage and inflammation

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Murphy L. Y. Wan ◽  
Paul C. Turner ◽  
Vanessa A. Co ◽  
M. F. Wang ◽  
Khaled M. A. Amiri ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Intestinal Inflammation ◽  
Health Concern ◽  
Heme Oxygenase 1 ◽  
Antioxidant Enzyme Activities ◽  
Transferase Activity ◽  
Nuclear Factor ◽  
Ht 29

AbstractExtensive research has revealed the association of continued oxidative stress with chronic inflammation, which could subsequently affect many different chronic diseases. The mycotoxin deoxynivalenol (DON) frequently contaminates cereals crops worldwide, and are a public health concern since DON ingestion may result in persistent intestinal inflammation. There has also been considerable attention over the potential of DON to provoke oxidative stress. In this study, the cytoprotective effect of Schisandrin A (Sch A), one of the most abundant active dibenzocyclooctadiene lignans in the fruit of Schisandra chinensis (Turcz.) Baill (also known as Chinese magnolia-vine), was investigated in HT-29 cells against DON-induced cytotoxicity, oxidative stress and inflammation. Sch A appeared to protect against DON-induced cytotoxicity in HT-29 cells, and significantly lessened the DON-stimulated intracellular reactive oxygen species and nitrogen oxidative species production. Furthermore, Sch A lowered DON-induced catalase, superoxide dismutase and glutathione peroxidase antioxidant enzyme activities but maintains glutathione S transferase activity and glutathione levels. Mechanistic studies suggest that Sch A reduced DON-induced oxidative stress by down-regulating heme oxygenase-1 expression via nuclear factor (erythroid-derived 2)-like 2 signalling pathway. In addition, Sch A decreased the DON-induced cyclooxygenase-2 expression and prostaglandin E2 production and pro-inflammatory cytokine interleukin 8 expression and secretion. This may be mediated by preventing DON-induced translocation of nuclear factor-κB, as well as activation of mitogen-activated protein kinases pathways. In the light of these findings, we concluded that Sch A exerted a cytoprotective role in DON-induced toxicity in vitro, and it would be valuable to examine in vivo effects.

scholarly journals Ursodeoxycholic acid protects against intestinal barrier breakdown by promoting enterocyte migration via EGFR- and COX-2-dependent mechanisms

2018 ◽  
Vol 315 (2) ◽  
pp. G259-G271 ◽  
Author(s):  
Jamie M. Golden ◽  
Oswaldo H. Escobar ◽  
Michelle V. L. Nguyen ◽  
Michael U. Mallicote ◽  
Patil Kavarian ◽  
...  
Keyword(s):  
Cell Migration ◽  
Epithelial Cell ◽  
Ursodeoxycholic Acid ◽  
Intestinal Epithelial Cell ◽  
Growth Factor Receptor ◽  
Intestinal Barrier ◽  
Intestinal Epithelial ◽  
Epithelial Cell Migration ◽  
Cox 2

The intestinal barrier is often disrupted in disease states, and intestinal barrier failure leads to sepsis. Ursodeoxycholic acid (UDCA) is a bile acid that may protect the intestinal barrier. We hypothesized that UDCA would protect the intestinal epithelium in injury models. To test this hypothesis, we utilized an in vitro wound-healing assay and a mouse model of intestinal barrier injury. We found that UDCA stimulates intestinal epithelial cell migration in vitro, and this migration was blocked by inhibition of cyclooxygenase 2 (COX-2), epidermal growth factor receptor (EGFR), or ERK. Furthermore, UDCA stimulated both COX-2 induction and EGFR phosphorylation. In vivo UDCA protected the intestinal barrier from LPS-induced injury as measured by FITC dextran leakage into the serum. Using 5-bromo-2′-deoxyuridine and 5-ethynyl-2′-deoxyuridine injections, we found that UDCA stimulated intestinal epithelial cell migration in these animals. These effects were blocked with either administration of Rofecoxib, a COX-2 inhibitor, or in EGFR-dominant negative Velvet mice, wherein UDCA had no effect on LPS-induced injury. Finally, we found increased COX-2 and phosphorylated ERK levels in LPS animals also treated with UDCA. Taken together, these data suggest that UDCA can stimulate intestinal epithelial cell migration and protect against acute intestinal injury via an EGFR- and COX-2-dependent mechanism. UDCA may be an effective treatment to prevent the early onset of gut-origin sepsis. NEW & NOTEWORTHY In this study, we show that the secondary bile acid ursodeoxycholic acid stimulates intestinal epithelial cell migration after cellular injury and also protects the intestinal barrier in an acute rodent injury model, neither of which has been previously reported. These effects are dependent on epidermal growth factor receptor activation and downstream cyclooxygenase 2 upregulation in the small intestine. This provides a potential treatment for acute, gut-origin sepsis as seen in diseases such as necrotizing enterocolitis.

scholarly journals Emerging Significance of Ginsenosides as Potentially Reversal Agents of Chemoresistance in Cancer Therapy

2021 ◽  
Vol 12 ◽  
Author(s):  
Jin-Feng Xu ◽  
Yan Wan ◽  
Fei Tang ◽  
Lu Chen ◽  
Yu Yang ◽  
...  
Keyword(s):  
Cancer Therapy ◽  
Cancer Susceptibility ◽  
Tyrosine Phosphatase ◽  
Growth Factor Receptor ◽  
Future Research ◽  
Related Factor ◽  
Nuclear Factor ◽  
Reversal Agents

Chemoresistance has become a prevalent phenomenon in cancer therapy, which alleviates the effect of chemotherapy and makes it difficult to break the bottleneck of the survival rate of tumor patients. Current approaches for reversing chemoresistance are poorly effective and may cause numerous new problems. Therefore, it is urgent to develop novel and efficient drugs derived from natural non-toxic compounds for the reversal of chemoresistance. Researches in vivo and in vitro suggest that ginsenosides are undoubtedly low-toxic and effective options for the reversal of chemoresistance. The underlying mechanism of reversal of chemoresistance is correlated with inhibition of drug transporters, induction of apoptosis, and modulation of the tumor microenvironment(TME), as well as the modulation of signaling pathways, such as nuclear factor erythroid-2 related factor 2 (NRF2)/AKT, lncRNA cancer susceptibility candidate 2(CASC2)/ protein tyrosine phosphatase gene (PTEN), AKT/ sirtuin1(SIRT1), epidermal growth factor receptor (EGFR)/ phosphatidylinositol 3-kinase (PI3K)/AKT, PI3K/AKT/ mammalian target of rapamycin(mTOR) and nuclear factor-κB (NF-κB). Since the effects and the mechanisms of ginsenosides on chemoresistance reversal have not yet been reviewed, this review summarized comprehensively experimental data in vivo and in vitro to elucidate the functional roles of ginsenosides in chemoresistance reversal and shed light on the future research of ginsenosides.

scholarly journals MMP-9-induced increase in intestinal epithelial tight permeability is mediated by p38 kinase signaling pathway activation of MLCK gene

2019 ◽  
Vol 316 (2) ◽  
pp. G278-G290 ◽  
Author(s):  
Rana Al-Sadi ◽  
Moustafa Youssef ◽  
Manmeet Rawat ◽  
Shuhong Guo ◽  
Karol Dokladny ◽  
...  
Keyword(s):  
Protein Expression ◽  
Intestinal Permeability ◽  
Barrier Function ◽  
Intestinal Inflammation ◽  
Gene Activity ◽  
Intestinal Epithelial ◽  
P38 Kinase ◽  
Kinase Signaling Pathway

Matrix metalloproteinase-9 (MMP-9) has been implicated as being an important pathogenic factor in inflammatory bowel disease (IBD). MMP-9 is markedly elevated in intestinal tissue of patients with IBD, and IBD patients have a defective intestinal tight-junction (TJ) barrier manifested by an increase in intestinal permeability. The loss of intestinal epithelial barrier function is an important contributing factor in the development and prolongation of intestinal inflammation; however, the role of MMP-9 in intestinal barrier function remains unclear. The purpose of this study was to investigate the effect of MMP-9 on the intestinal epithelial TJ barrier and to delineate the intracellular mechanisms involved by using in vitro (filter-grown Caco-2 monolayers) and in vivo (mouse small intestine recycling perfusion) systems. MMP-9 caused a time- and dose-dependent increase in Caco-2 TJ permeability. MMP-9 also caused an increase in myosin light-chain kinase (MLCK) gene activity, protein expression, and enzymatic activity. The pharmacological MLCK inhibition and siRNA-induced knockdown of MLCK inhibited the MMP-9-induced increase in Caco-2 TJ permeability. MMP-9 caused a rapid activation of the p38 kinase signaling pathway and inhibition of p38 kinase activity prevented the MMP-9-induced increase in MLCK gene activity and the increase in Caco-2 TJ permeability. MMP-9 also caused an increase in mouse intestinal permeability in vivo, which was accompanied by an increase in MLCK expression. The MMP-9-induced increase in mouse intestinal permeability was inhibited in MLCK-deficient mice. These data show for the first time that the MMP-9-induced increase in intestinal TJ permeability in vitro and in vivo was mediated by the p38 kinase signal transduction pathway upregulation of MLCK gene activity and that therapeutic targeting of these pathways can prevent the MMP-9-induced increase in intestinal TJ permeability. NEW & NOTEWORTHY MMP-9 is highly elevated in patients with IBD. IBD patients have compromised intestinal TJ barrier function manifested by an increase in intestinal permeability and intestinal inflammation. This study shows that MMP-9, at clinically achievable concentrations, causes an increase in intestinal TJ permeability in vitro and in vivo. In addition, a MMP-9-induced increase in intestinal TJ permeability was mediated by an increase in MLCK gene and protein expression via the p38 kinase pathway.

scholarly journals MicroRNA-122a Regulates Zonulin by Targeting EGFR in Intestinal Epithelial Dysfunction

2017 ◽  
Vol 42 (2) ◽  
pp. 848-858 ◽  
Author(s):  
Bin Zhang ◽  
Yinghai Tian ◽  
Ping Jiang ◽  
Yanqiong Jiang ◽  
Chao Li ◽  
...  
Keyword(s):  
Target Gene ◽  
Growth Factor Receptor ◽  
Intestinal Barrier ◽  
Expression Level ◽  
Intestinal Epithelial ◽  
Barrier Methods ◽  
Clinical Specimens ◽  
Epithelial Culture

Background/Aims: This study aimed to investigate the role of microRNA (miR)-122a in regulating zonulin during the modulation of intestinal barrier. Methods: Zonulin proteins and their target gene expression were analyzed in miR-122a-overexpressing cell lines and in the target gene of epidermal growth factor receptor (EGFR). An mmu-miR-122a intestinal epithelial conditional transgenic (miR-122a-TG) mouse model was established to investigate EGFR and zonulin expression. MiR-122a was also detected in the clinical specimens of inflammatory bowel disease. Results: EGFR was identified as a target gene of miR-122a. The expression level of miR-122a was positively correlated with that of zonulin. The expression level of zonulin was significantly increased, whereas the expression level of EGFR was significantly decreased in the miR-122a-TG mice and in the corresponding primary epithelial culture (P < 0.05). These results were consistent with the data of the clinical specimens. Conclusions: miR-122a could be a positive factor of zonulin by targeting EGFR, which increased the intestinal epithelial permeability in vivo and in vitro.

scholarly journals Development of Heptylmannoside-Based Glycoconjugate Antiadhesive Compounds against Adherent-Invasive Escherichia coli Bacteria Associated with Crohn's Disease

mBio ◽  
2015 ◽  
Vol 6 (6) ◽  
Author(s):  
Adeline Sivignon ◽  
Xibo Yan ◽  
Dimitri Alvarez Dorta ◽  
Richard Bonnet ◽  
Julie Bouckaert ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Crohn’S Disease ◽  
Crohn's Disease ◽  
Intestinal Inflammation ◽  
Intestinal Epithelial ◽  
Content Type ◽  
Type 1 Pili

ABSTRACTThe ileal lesions of Crohn's disease (CD) patients are colonized by adherent-invasiveEscherichia coli(AIEC) bacteria. These bacteria adhere to mannose residues expressed by CEACAM6 on host cells in a type 1 pilus-dependent manner. In this study, we investigated different antagonists of FimH, the adhesin of type 1 pili, for their ability to block AIEC adhesion to intestinal epithelial cells (IEC). Monovalent and multivalent derivatives ofn-heptyl α-d-mannoside (HM), a nanomolar antagonist of FimH, were testedin vitroin IEC infected with the AIEC LF82 strain andin vivoby oral administration to CEACAM6-expressing mice infected with LF82 bacteria.In vitro, multivalent derivatives were more potent than the monovalent derivatives, with a gain of efficacy superior to their valencies, probably owing to their ability to form bacterial aggregates. Of note, HM and the multi-HM glycoconjugates exhibited lower efficacyin vivoin decreasing LF82 gut colonization. Interestingly, HM analogues functionalized with an isopropylamide (1A-HM) or β-cyclodextrin pharmacophore at the end of the heptyl tail (1CD-HM) exerted beneficial effectsin vivo. These two compounds strongly decreased the amount of LF82 bacteria in the feces of mice and that of bacteria associated with the gut mucosa when administered orally at a dose of 10 mg/kg of body weight after infection. Importantly, signs of colitis and intestinal inflammation induced by LF82 infection were also prevented. These results highlight the potential of the antiadhesive compounds to treat CD patients abnormally colonized by AIEC bacteria and point to an alternative to the current approach focusing on blocking proinflammatory mediators.IMPORTANCECurrent treatments for Crohn's disease (CD), including immunosuppressive agents, anti-tumor necrosis factor alpha (anti-TNF-α) and anti-integrin antibodies, focus on the symptoms but not on the cause of the disease. Adherent-invasiveEscherichia coli(AIEC) bacteria abnormally colonize the ileal mucosa of CD patients via the interaction of the mannose-specific adhesin FimH of type 1 pili with CEACAM6 mannosylated proteins expressed on the epithelial cell surface. Thus, we decided to develop an antiadhesive strategy based on synthetic FimH antagonists specifically targeting AIEC bacteria that would decrease intestinal inflammation. Heptylmannoside (HM)-based glycocompounds strongly inhibit AIEC adhesion to intestinal epithelial cellsin vitro. The antiadhesive effect of two of these compounds of relatively simple chemical structure was also observedin vivoin AIEC-infected CEACAM6-expressing mice and was associated with a reduction in the signs of colitis. These results suggest a new therapeutic approach for CD patients colonized by AIEC bacteria, based on the development of synthetic FimH antagonists.

Migration of IEC-6 cells: a model for mucosal healing

1992 ◽  
Vol 263 (3) ◽  
pp. G426-G435 ◽  
Author(s):  
S. A. McCormack ◽  
M. J. Viar ◽  
L. R. Johnson
Keyword(s):  
Cell Migration ◽  
Dna Synthesis ◽  
Actin Polymerization ◽  
Mucosal Healing ◽  
Intestinal Epithelial ◽  
Wound Edge ◽  
Good Correspondence ◽  
Polyamine Synthesis ◽  
Small Intestinal

Cell migration is the principal force behind the early restitution of erosions of the mucosa of the gastrointestinal tract. Despite the importance of cell migration to healing, no attempts to study the process in culture have been reported. We have attempted to standardize conditions for migration and test the migration responses of the small intestinal epithelial crypt cell line IEC-6 in some experimental situations already well known in vivo. We found good correspondence between in culture and in vivo on the following points: 1) migration was independent of DNA synthesis; 2) DNA synthesis was not concentrated at the wound edge; and 3) inhibition of actin polymerization stopped migration altogether. In addition, the presence of an extracellular matrix maximized migration. Protein inhibitors with different modes of action inhibited cell migration to different degrees, not always commensurate with their inhibition of protein synthesis. Cell surface proteoglycans were important; hyaluronic acid had an effect, but the secretion of a migration-stimulating substance by wounded cells was equivocal. Significantly, alpha-difluoromethylornithine (DFMO), which inhibits ornithine decarboxylase and polyamine synthesis, almost totally prevented cell migration. Because DFMO also prevents healing of mucosal erosions in vivo, we believe that this model can be used, keeping in mind its spatial limitations, to study the process of cell migration involved in the early restitution of mucosal erosions.

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