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Sample records for intestinal epithelial crypt

  1. Energy metabolism in intestinal epithelial cells during maturation along the crypt-villus axis

    Science.gov (United States)

    Yang, Huansheng; Wang, Xiaocheng; Xiong, Xia; Yin, Yulong

    2016-01-01

    Intestinal epithelial cells continuously migrate and mature along crypt-villus axis (CVA), while the changes in energy metabolism during maturation are unclear in neonates. The present study was conducted to test the hypothesis that the energy metabolism in intestinal epithelial cells would be changed during maturation along CVA in neonates. Eight 21-day-old suckling piglets were used. Intestinal epithelial cells were isolated sequentially along CVA, and proteomics was used to analyze the changes in proteins expression in epithelial cells along CVA. The identified differentially expressed proteins were mainly involved in cellular process, metabolic process, biological regulation, pigmentation, multicellular organizational process and so on. The energy metabolism in intestinal epithelial cells of piglets was increased from the bottom of crypt to the top of villi. Moreover, the expression of proteins related to the metabolism of glucose, most of amino acids, and fatty acids was increased in intestinal epithelial cells during maturation along CVA, while the expression of proteins related to glutamine metabolism was decreased from crypt to villus tip. The expression of proteins involved in citrate cycle was also increased intestinal epithelial cells during maturation along CVA. Moreover, dietary supplementation with different energy sources had different effects on intestinal structure of weaned piglets. PMID:27558220

  2. Fibroblast growth factor receptor-3 is expressed in undifferentiated intestinal epithelial cells during murine crypt morphogenesis.

    Science.gov (United States)

    Vidrich, Alda; Buzan, Jenny M; Ilo, Chibuzo; Bradley, Leigh; Skaar, Kirstin; Cohn, Steven M

    2004-05-01

    Prior studies have demonstrated that fibroblast growth factor receptor-3 (FGFR-3) regulates proliferation of undifferentiated intestinal epithelial cells in vitro. However, the function(s) of FGFR-3-mediated signaling during intestinal development and epithelial differentiation in vivo remain unknown. The goal of this study was to define the temporal, regional, and cell-specific patterns of FGFR-3 expression and its ligands during normal intestinal ontogeny and epithelial regeneration. Both the IIIb and IIIc isoforms of FGFR-3 mRNA, which result from differential splicing of the FGFR-3 primary transcript, were detected in mouse small intestine as early as embryonic day 16. FGFR-3 levels peaked in the small intestine from 7 to 21 days after birth and decreased thereafter to reach the low levels observed in adult mice. FGFR-3 IIIb and IIIc mRNA levels were highest in the duodenum and proximal jejunum with lower levels of both seen in the distal jejunum, ileum, and colon. FGFR-3 was expressed in a subset of proliferating undifferentiated crypt epithelial cells located in the intervillous epithelium and in the lower half of nascently forming crypts but not in differentiated epithelial cell types. FGFR-3 IIIb was the dominant isoform expressed in both small intestinal and colonic crypts. Expression of FGF1, FGF2, and FGF9, known ligands of FGFR-3, paralleled patterns of FGFR-3 expression during gut development. These data suggest that signaling through FGFR-3 plays a role in regulating morphogenic events involved in formation of intestinal crypts and/or the fate of epithelial stem cells.

  3. Fluorescent labelling of intestinal epithelial cells reveals independent long-lived intestinal stem cells in a crypt

    Energy Technology Data Exchange (ETDEWEB)

    Horita, Nobukatsu [Department of Gastroenterology and Hepatology, Graduate School, Tokyo Medical and Dental University (Japan); Tsuchiya, Kiichiro, E-mail: kii.gast@tmd.ac.jp [Department of Advanced Therapeutics for Gastrointestinal Diseases, Graduate School, Tokyo Medical and Dental University (Japan); Hayashi, Ryohei [Department of Gastroenterology and Hepatology, Graduate School, Tokyo Medical and Dental University (Japan); Department of Gastroenterology and Metabolism, Hiroshima University (Japan); Fukushima, Keita; Hibiya, Shuji; Fukuda, Masayoshi; Kano, Yoshihito; Mizutani, Tomohiro; Nemoto, Yasuhiro; Yui, Shiro [Department of Gastroenterology and Hepatology, Graduate School, Tokyo Medical and Dental University (Japan); Okamoto, Ryuichi; Nakamura, Tetsuya [Department of Advanced Therapeutics for Gastrointestinal Diseases, Graduate School, Tokyo Medical and Dental University (Japan); Watanabe, Mamoru [Department of Gastroenterology and Hepatology, Graduate School, Tokyo Medical and Dental University (Japan)

    2014-11-28

    Highlights: • Lentivirus mixed with Matrigel enables direct infection of intestinal organoids. • Our original approach allows the marking of a single stem cell in a crypt. • Time-lapse imaging shows the dynamics of a single stem cell. • Our lentivirus transgene system demonstrates plural long-lived stem cells in a crypt. - Abstract: Background and aims: The dynamics of intestinal stem cells are crucial for regulation of intestinal function and maintenance. Although crypt stem cells have been identified in the intestine by genetic marking methods, identification of plural crypt stem cells has not yet been achieved as they are visualised in the same colour. Methods: Intestinal organoids were transferred into Matrigel® mixed with lentivirus encoding mCherry. The dynamics of mCherry-positive cells was analysed using time-lapse imaging, and the localisation of mCherry-positive cells was analysed using 3D immunofluorescence. Results: We established an original method for the introduction of a transgene into an organoid generated from mouse small intestine that resulted in continuous fluorescence of the mCherry protein in a portion of organoid cells. Three-dimensional analysis using confocal microscopy showed a single mCherry-positive cell in an organoid crypt that had been cultured for >1 year, which suggested the presence of long-lived mCherry-positive and -negative stem cells in the same crypt. Moreover, a single mCherry-positive stem cell in a crypt gave rise to both crypt base columnar cells and transit amplifying cells. Each mCherry-positive and -negative cell contributed to the generation of organoids. Conclusions: The use of our original lentiviral transgene system to mark individual organoid crypt stem cells showed that long-lived plural crypt stem cells might independently serve as intestinal epithelial cells, resulting in the formation of a completely functional villus.

  4. RGD-Dependent Epithelial Cell-Matrix Interactions in the Human Intestinal Crypt

    Directory of Open Access Journals (Sweden)

    Yannick D. Benoit

    2012-01-01

    Full Text Available Interactions between the extracellular matrix (ECM and integrin receptors trigger structural and functional bonds between the cell microenvironment and the cytoskeleton. Such connections are essential for adhesion structure integrity and are key players in regulating transduction of specific intracellular signals, which in turn regulate the organization of the cell microenvironment and, consequently, cell function. The RGD peptide-dependent integrins represent a key subgroup of ECM receptors involved in the maintenance of epithelial homeostasis. Here we review recent findings on RGD-dependent ECM-integrin interactions and their roles in human intestinal epithelial crypt cells.

  5. Mammalian Target of Rapamycin Signaling Pathway Changes with Intestinal Epithelial Cells Renewal Along Crypt-Villus Axis

    Directory of Open Access Journals (Sweden)

    Huansheng Yang

    2016-07-01

    Full Text Available Background/Aims: Understanding the mechanism that involves in regulating epithelial cells renewal is the fundamental of regulating intestinal mucosa development and functions and related diseases. The mechanistic target of rapamycin (mTOR signaling pathway involves in controlling various major processes by integrating intracellular and extracellular cues. The present experiment was conducted to test the correlation between the mTOR signaling pathway and intestinal epithelial cells renewal along crypt-villus axis (CVA. Methods: Intestinal epithelial cells were sequentially isolated from the jejunum of piglets along CVA, and the amount or phosphorylation level of proteins involved in cell cycle, mTOR signaling pathway, gene expression, and the antioxidant capacity in the isolated cells were measured. Results: The results showed that the amount of proteins involved in cell cycle decreased from crypt to villus tip. The amount or phosphorylation level of proteins related to mTOR signaling pathway in intestinal epithelial cells mainly decreased during maturation along CVA. The amount of proteins involved in gene expression and the antioxidant capacity also decreased from crypt to the top of villi. Conclusions: These results indicate that the mTOR signaling pathway may be involved in regulating the intestinal epithelial cells renewal along CVA and it may partly through affecting the antioxidant capacity and gene expression of intestinal epithelial cells. Further histological verification is needed to confirm the results of the present experiments.

  6. [Study on detoxication of euphorbia pekinensis radix processed with vinegar on rat small intestinal crypt epithelial cells IEC-6].

    Science.gov (United States)

    Cao, Yu-Dan; Yan, Xiao-Jing; Zhang, Li; Ding, An-Wei

    2014-03-01

    To compare the difference of Euphorbia Pekinensis Radix before and after being processed with vinegar in the toxicity on rat small intestinal crypt epithelial cells IEC-6, and make a preliminary study on the mechanism of detoxication of Euphorbia Pekinensis Radix processed with vinegar. With rat small intestinal crypt epithelial cells IEC-6 as the study object, the MTT method was adopted to detect the effect of Euphorbia Pekinensis Radix before and after being processed with vinegar on IEC-6 cell activity. The morphology of cells were observed by the inverted microscope. The down-regulated mitochondrial apoptosis pathway of enterocytes caused by the vinegar processing was analyzed by using the high content screening. Compared with the negative control group, the proliferation inhibition experiment showed that Euphorbia Pekinensis Radix showed a relatively high intestinal cell toxicity (P IEC-6 cell membrane, so as to provide a basis for further explanation of the detoxication mechanism of Euphorbia Pekinensis Radix processed with vinegar.

  7. Protein kinase D1 mediates stimulation of DNA synthesis and proliferation in intestinal epithelial IEC-18 cells and in mouse intestinal crypts.

    Science.gov (United States)

    Sinnett-Smith, James; Rozengurt, Nora; Kui, Robert; Huang, Carlos; Rozengurt, Enrique

    2011-01-07

    We examined whether protein kinase D1 (PKD1), the founding member of a new protein kinase family, plays a critical role in intestinal epithelial cell proliferation. Our results demonstrate that PKD1 activation is sustained, whereas that of PKD2 is transient in intestinal epithelial IEC-18 stimulated with the G(q)-coupled receptor agonists angiotensin II or vasopressin. PKD1 gene silencing utilizing small interfering RNAs dramatically reduced DNA synthesis and cell proliferation in IEC-18 cells stimulated with G(q)-coupled receptor agonists. To clarify the role of PKD1 in intestinal epithelial cell proliferation in vivo, we generated transgenic mice that express elevated PKD1 protein in the intestinal epithelium. Transgenic PKD1 exhibited constitutive catalytic activity and phosphorylation at the activation loop residues Ser(744) and Ser(748) and on the autophosphorylation site, Ser(916). To examine whether PKD1 expression stimulates intestinal cell proliferation, we determined the rate of crypt cell DNA synthesis by detection of 5-bromo-2-deoxyuridine incorporated into the nuclei of crypt cells of the ileum. Our results demonstrate a significant increase (p < 0.005) in DNA-synthesizing cells in the crypts of two independent lines of PKD1 transgenic mice as compared with non-transgenic littermates. Morphometric analysis showed a significant increase in the length and in the total number of cells per crypt in the transgenic PKD1 mice as compared with the non-transgenic littermates (p < 0.01). Thus, transgenic PKD1 signaling increases the number of cells per crypt by stimulating the rate of crypt cell proliferation. Collectively, our results indicate that PKD1 plays a role in promoting cell proliferation in intestinal epithelial cells both in vitro and in vivo.

  8. Histoplanimetrical study on the relationship between invasion of indigenous bacteria into intestinal crypts and proliferation of epithelial cells in rat ascending colon.

    Science.gov (United States)

    Mantani, Youhei; Takahara, Ei-Ichirou; Takeuchi, Takashi; Kawano, Junichi; Yokoyama, Toshifumi; Hoshi, Nobuhiko; Kitagawa, Hiroshi

    2013-07-31

    The relationship between the invasion of indigenous bacteria into intestinal crypts and the proliferation of epithelial cells was histoplanimetrically investigated in the rat ascending colon. Indigenous bacteria preferentially adhered to the intestinal superficial epithelial cells in the mesenterium-attached mucosa (MAM) compared to those in the mesenterium-non-attached mucosa (MNM). Intestinal crypts with indigenous bacteria were also significantly more frequently found in MAM than in MNM. Total epithelial cells, columnar epithelial cells and goblet cells were significantly more abundant in the intestinal crypts with no-indigenous bacteria in MAM (MAM-C) than those in MNM (MNM-C), whereas the columnar epithelial cells were less abundant in MAM-C than in the intestinal crypts with indigenous bacteria in MAM (MAM-C-B). Columnar epithelial cells and goblet cells immuno-positive for proliferating cell nuclear antigen (PCNA) in MAM-C were more abundant than those in MNM-C, but less abundant than those in MAM-C-B. Toll-like receptor (TLR)-2, -4 and -9 were immuno-positive in the striated borders of the intestinal superficial epithelial cells, but their positive intensities were weaker in MAM than in MNM. From these findings, indigenous bacteria were confirmed to preferentially settle on the intestinal superficial epithelium of MAM in the rat ascending colon, and low TLRs-expression might contribute to the preferential settlement of indigenous bacteria in MAM. The increase of proliferating epithelial cells is probably induced by the invasion of indigenous bacteria into the intestinal crypts of MAM.

  9. Naturally Occurring Deletion Mutants of the Pig-Specific, Intestinal Crypt Epithelial Cell Protein CLCA4b without Apparent Phenotype.

    Directory of Open Access Journals (Sweden)

    Stephanie Plog

    Full Text Available The human CLCA4 (chloride channel regulator, calcium-activated modulates the intestinal phenotype of cystic fibrosis (CF patients via an as yet unknown pathway. With the generation of new porcine CF models, species-specific differences between human modifiers of CF and their porcine orthologs are considered critical for the translation of experimental data. Specifically, the porcine ortholog to the human CF modulator gene CLCA4 has recently been shown to be duplicated into two separate genes, CLCA4a and CLCA4b. Here, we characterize the duplication product, CLCA4b, in terms of its genomic structure, tissue and cellular expression patterns as well as its in vitro electrophysiological properties. The CLCA4b gene is a pig-specific duplication product of the CLCA4 ancestor and its protein is exclusively expressed in small and large intestinal crypt epithelial cells, a niche specifically occupied by no other porcine CLCA family member. Surprisingly, a unique deleterious mutation of the CLCA4b gene is spread among modern and ancient breeds in the pig population, but this mutation did not result in an apparent phenotype in homozygously affected animals. Electrophysiologically, neither the products of the wild type nor of the mutated CLCA4b genes were able to evoke a calcium-activated anion conductance, a consensus feature of other CLCA proteins. The apparently pig-specific duplication of the CLCA4 gene with unique expression of the CLCA4b protein variant in intestinal crypt epithelial cells where the porcine CFTR is also present raises the question of whether it may modulate the porcine CF phenotype. Moreover, the naturally occurring null variant of CLCA4b will be valuable for the understanding of CLCA protein function and their relevance in modulating the CF phenotype.

  10. Crypt region localization of intestinal stem cells in adults

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The intestinal epithelial lining plays a central role in the digestion and absorption of nutrients, but exists in a harsh luminal environment that necessitates continual renewal. This renewal process involves epithelial cell proliferation in the crypt base and later cell migration from the crypt base to the luminal surface. This process is dependent on multi-potent progenitor cells, or stem cells, located in each crypt. There are about 4 to 6 stem cells per crypt, and these stem cells are believed to generate distinct end-differentiated epithelial cell types, including absorptive cells, goblet cells, enteroendocrine cells and Paneth cells, while also maintaining their own progenitor cell state. Earlier studies suggested that intestinal stem cells were located either in the crypt base interspersed between the Paneth cells [i.e. Crypt base columnar (CBC) cell model] or at an average position of 4 cells from the crypt base [I.e. Label-retaining cells (LRC +4) model]. Recent studies have employed biomarkers in the in vivo mammalian state to more precisely evaluate the location of these progenitor cells in the intestinal crypt. Most notable of these novel markers are Lgr5, a gene that encodes a G-protein-coupled receptor with expression restricted to CBC cells, and Bmi 1, which encodes a chromatin remodeling protein expressed by LRC. These studies raise the possibility that there may be separate stem cell lines or different states of stem cell activation involved in the renewal of normal mammalian intestinal tract.

  11. File list: Unc.Dig.05.AllAg.Intestinal_crypt [Chip-atlas[Archive

    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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  13. File list: His.Dig.50.AllAg.Intestinal_crypt [Chip-atlas[Archive

    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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  18. Type 3 innate lymphoid cells maintain intestinal epithelial stem cells after tissue damage

    NARCIS (Netherlands)

    P. Aparicio-Domingo (Patricia); M. Romera-Hernandez (Monica); J.J. Karrich (Julien J.); F.H.J. Cornelissen (Ferry); N. Papazian (Natalie); D.J. Lindenbergh-Kortleve (Dicky); J.A. Butler (James A.); L. Boon (Louis); M. Coles (Mark); J.N. Samsom (Janneke); T. Cupedo (Tom)

    2015-01-01

    textabstractDisruption of the intestinal epithelial barrier allows bacterial translocation and predisposes to destructive inflammation. To ensure proper barrier composition, crypt-residing stem cells continuously proliferate and replenish all intestinal epithelial cells within days. As a consequence

  19. Critical role of microbiota within cecal crypts on the regenerative capacity of the intestinal epithelium following surgical stress.

    Science.gov (United States)

    Zaborin, Alexander; Krezalek, Monika; Hyoju, Sanjiv; Defazio, Jennifer R; Setia, Namrata; Belogortseva, Natalia; Bindokas, Vytautas P; Guo, Qiti; Zaborina, Olga; Alverdy, John C

    2017-02-01

    Cecal crypts represent a unique niche that are normally occupied by the commensal microbiota. Due to their density and close proximity to stem cells, microbiota within cecal crypts may modulate epithelial regeneration. Here we demonstrate that surgical stress, a process that invariably involves a short period of starvation, antibiotic exposure, and tissue injury, results in cecal crypt evacuation of their microbiota. Crypts devoid of their microbiota display pathophysiological features characterized by abnormal stem cell activation as judged by leucine-rich repeat-containing G protein-coupled receptor 5 (Lgr5) staining, expansion of the proliferative zone toward the tips of the crypts, and an increase in apoptosis. In addition, crypts devoid of their microbiota display loss of their regenerative capacity as assessed by their ability to form organoids ex vivo. When a four-member human pathogen community isolated from the stool of a critically ill patient is introduced into the cecum of mice with empty crypts, crypts become occupied by the pathogens and further disruption of crypt homeostasis is observed. Fecal microbiota transplantation restores the cecal crypts' microbiota, normalizes homeostasis within crypts, and reestablishes crypt regenerative capacity. Taken together, these findings define an emerging role for the microbiota within cecal crypts to maintain epithelial cell homeostasis in a manner that may enhance recovery in response to the physiological stress imposed by the process of surgery. This study provides novel insight into the process by which surgical injury places the intestinal epithelium at risk for colonization by pathogenic microbes and impairment of its regenerative capacity via loss of its microbiota. We show that fecal transplant restores crypt homeostasis in association with repopulation of the microbiota within cecal crypts. Copyright © 2017 the American Physiological Society.

  20. Inhibition of Notch signaling reduces the number of surviving Dclk1+ reserve crypt epithelial stem cells following radiation injury.

    Science.gov (United States)

    Qu, Dongfeng; May, Randal; Sureban, Sripathi M; Weygant, Nathaniel; Chandrakesan, Parthasarathy; Ali, Naushad; Li, Linheng; Barrett, Terrence; Houchen, Courtney W

    2014-03-01

    We have previously reported that doublecortin-like kinase 1 (Dclk1) is a putative intestinal stem cell (ISC) marker. In this report, we evaluated the use of Dclk1 as a marker of surviving ISCs in response to treatment with high-dose total body irradiation (TBI). Both apoptotic and mitotic Dclk1(+) cells were observed 24 h post-TBI associated with a corresponding loss of intestinal crypts observed at 84 h post-TBI. Although the Notch signaling pathway plays an important role in regulating proliferation and lineage commitment within the intestine, its role in ISC function in response to severe genotoxic injury is not yet fully understood. We employed the microcolony assay to functionally assess the effects of Notch inhibition with difluorophenacetyl-l-alanyl-S-phenylglycine t-butyl ester (DAPT) on intestinal crypt stem cell survival following severe (>8 Gy) radiation injury. Following treatment with DAPT, we observed a nearly 50% reduction in the number of surviving Dclk1(+) crypt epithelial cells at 24 h after TBI and similar reduction in the number of surviving small intestinal crypts at 84 h. These data indicate that inhibition of Notch signaling decreases ISC survival following radiation injury, suggesting that the Notch signaling pathway plays an important role in ISC-mediated crypt regeneration. These results also suggest that crypt epithelial cell Dclk1 expression can be used as one potential marker to evaluate the early survival of ISCs following severe radiation injury.

  1. EP receptor expression in human intestinal epithelium and localization relative to the stem cell zone of the crypts.

    Science.gov (United States)

    Olsen Hult, Lene Th; Kleiveland, Charlotte R; Fosnes, Kjetil; Jacobsen, Morten; Lea, Tor

    2011-01-01

    There is substantial evidence for PGE2 affecting intestinal epithelial proliferation. PGE2 is also reported to be involved in the regulation of growth and differentiation in adult stem cells, both effects mediated by binding to EP-receptors. We have used the Lgr5 as a marker to scrutinize EP-receptor and COX expression in human intestinal epithelial cells with focus on the stem cell area of the crypts. Normal tissue from ileum and colon, but also duodenal biopsies from patients with untreated celiac disease, were investigated by immunohistochemistry and RT-PCR. The combination of fresh flash-frozen tissue and laser microdissection made it possible to isolate RNA from the epithelial cell layer, only. In the small intestine, Lgr5 labels cells are in the +4 position, while in the colon, Lgr5 positive cells are localized to the crypt bottoms. Epithelial crypt cells of normal small intestine expressed neither EP-receptor mRNA nor COX1/2. However, crypt cells in tissue from patients with untreated celiac disease expressed EP2/4 receptor and COX1 mRNA. In the colon, the situation was different. Epithelial crypt cells from normal colon were found to express EP2/4 receptor and COX1/2 transcripts. Thus, there are distinct differences between normal human small intestine and colon with regard to expression of EP2/4 receptors and COX1/2. In normal colon tissue, PGE2-mediated signaling through EP-receptors 2/4 could be involved in regulation of growth and differentiation of the epithelium, while the lack of EP-receptor expression in the small intestinal tissue exclude the possibility of a direct effect of PGE2 on the crypt epithelial cells.

  2. EP receptor expression in human intestinal epithelium and localization relative to the stem cell zone of the crypts.

    Directory of Open Access Journals (Sweden)

    Lene Th Olsen Hult

    Full Text Available There is substantial evidence for PGE2 affecting intestinal epithelial proliferation. PGE2 is also reported to be involved in the regulation of growth and differentiation in adult stem cells, both effects mediated by binding to EP-receptors. We have used the Lgr5 as a marker to scrutinize EP-receptor and COX expression in human intestinal epithelial cells with focus on the stem cell area of the crypts. Normal tissue from ileum and colon, but also duodenal biopsies from patients with untreated celiac disease, were investigated by immunohistochemistry and RT-PCR. The combination of fresh flash-frozen tissue and laser microdissection made it possible to isolate RNA from the epithelial cell layer, only. In the small intestine, Lgr5 labels cells are in the +4 position, while in the colon, Lgr5 positive cells are localized to the crypt bottoms. Epithelial crypt cells of normal small intestine expressed neither EP-receptor mRNA nor COX1/2. However, crypt cells in tissue from patients with untreated celiac disease expressed EP2/4 receptor and COX1 mRNA. In the colon, the situation was different. Epithelial crypt cells from normal colon were found to express EP2/4 receptor and COX1/2 transcripts. Thus, there are distinct differences between normal human small intestine and colon with regard to expression of EP2/4 receptors and COX1/2. In normal colon tissue, PGE2-mediated signaling through EP-receptors 2/4 could be involved in regulation of growth and differentiation of the epithelium, while the lack of EP-receptor expression in the small intestinal tissue exclude the possibility of a direct effect of PGE2 on the crypt epithelial cells.

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    Lifescience Database Archive (English)

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  1. Human intestinal circadian clock: expression of clock genes in colonocytes lining the crypt.

    Science.gov (United States)

    Pardini, L; Kaeffer, B; Trubuil, A; Bourreille, A; Galmiche, J-P

    2005-01-01

    Biological clock components have been detected in many epithelial tissues of the digestive tract of mammals (oral mucosa, pancreas, and liver), suggesting the existence of peripheral circadian clocks that may be entrainable by food. Our aim was to investigate the expression of main peripheral clock genes in colonocytes of healthy humans and in human colon carcinoma cell lines. The presence of clock components was investigated in single intact colonic crypts isolated by chelation from the biopsies of 25 patients (free of any sign of colonic lesions) undergoing routine colonoscopy and in cell lines of human colon carcinoma (Caco2 and HT29 clone 19A). Per-1, per-2, and clock mRNA were detected by real-time RT-PCR. The three-dimensional distributions of PER-1, PER-2, CLOCK, and BMAL1 proteins were recorded along colonic crypts by immunofluorescent confocal imaging. We demonstrate the presence of per-1, per-2, and clock mRNA in samples prepared from colonic crypts of 5 patients and in all cell lines. We also demonstrate the presence of two circadian clock proteins, PER-1 and CLOCK, in human colonocytes on crypts isolated from 20 patients (15 patients for PER-1 and 6 for CLOCK) and in colon carcinoma cells. Establishing the presence of clock proteins in human colonic crypts is the first step toward the study of the regulation of the intestinal circadian clock by nutrients and feeding rhythms.

  2. IGF1 stimulates crypt expansion via differential activation of 2 intestinal stem cell populations

    Science.gov (United States)

    Van Landeghem, Laurianne; Santoro, M. Agostina; Mah, Amanda T.; Krebs, Adrienne E.; Dehmer, Jeffrey J.; McNaughton, Kirk K.; Helmrath, Michael A.; Magness, Scott T.; Lund, P. Kay

    2015-01-01

    Insulin-like growth factor 1 (IGF1) has potent trophic effects on normal or injured intestinal epithelium, but specific effects on intestinal stem cells (ISCs) are undefined. We used Sox9-enhanced green fluorescent protein (EGFP) reporter mice that permit analyses of both actively cycling ISCs (Sox9-EGFPLow) and reserve/facultative ISCs (Sox9-EGFPHigh) to study IGF1 action on ISCs in normal intestine or during crypt regeneration after high-dose radiation-induced injury. We hypothesized that IGF1 differentially regulates proliferation and gene expression in actively cycling and reserve/facultative ISCs. IGF1 was delivered for 5 days using subcutaneously implanted mini-pumps in uninjured mice or after 14 Gy abdominal radiation. ISC numbers, proliferation, and transcriptome were assessed. IGF1 increased epithelial growth in nonirradiated mice and enhanced crypt regeneration after radiation. In uninjured and regenerating intestines, IGF1 increased total numbers of Sox9-EGFPLow ISCs and percentage of these cells in M-phase. IGF1 increased percentages of Sox9-EGFPHigh ISCs in S-phase but did not expand this population. Microarray revealed that IGF1 activated distinct gene expression signatures in the 2 Sox9-EGFP ISC populations. In vitro IGF1 enhanced enteroid formation by Sox9-EGFPHigh facultative ISCs but not Sox9-EGFPLow actively cycling ISCs. Our data provide new evidence that IGF1 activates 2 ISC populations via distinct regulatory pathways to promote growth of normal intestinal epithelium and crypt regeneration after irradiation.—Van Landeghem, L., Santoro, M. A., Mah, A. T., Krebs, A. E., Dehmer, J. J., McNaughton, K. K., Helmrath, M. A., Magness, S. T., Lund, P. K. IGF1 stimulates crypt expansion via differential activation of 2 intestinal stem cell populations. PMID:25837582

  3. Stem cell self-renewal in intestinal crypt

    Energy Technology Data Exchange (ETDEWEB)

    Simons, Benjamin D., E-mail: bds10@cam.ac.uk [Cavendish Laboratory, Department of Physics, J.J. Thomson Avenue, University of Cambridge, Cambridge CB3 0HE (United Kingdom); The Wellcome Trust/Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN (United Kingdom); Clevers, Hans, E-mail: h.clevers@hubrecht.eu [Hubrecht Institute, KNAW and University Medical Center Utrecht, Uppsalalaan 8, 3584 CT Utrecht (Netherlands)

    2011-11-15

    As a rapidly cycling tissue capable of fast repair and regeneration, the intestinal epithelium has emerged as a favored model system to explore the principles of adult stem cell biology. However, until recently, the identity and characteristics of the stem cell population in both the small intestine and colon has remained the subject of debate. Recent studies based on targeted lineage tracing strategies, combined with the development of an organotypic culture system, have identified the crypt base columnar cell as the intestinal stem cell, and have unveiled the strategy by which the balance between proliferation and differentiation is maintained. These results show that intestinal stem cells operate in a dynamic environment in which frequent and stochastic stem cell loss is compensated by the proliferation of neighboring stem cells. We review the basis of these experimental findings and the insights they offer into the mechanisms of homeostatic stem cell regulation.

  4. De Novo Formation of Insulin-Producing “Neo-β Cell Islets” from Intestinal Crypts

    Directory of Open Access Journals (Sweden)

    Yi-Ju Chen

    2014-03-01

    Full Text Available The ability to interconvert terminally differentiated cells could serve as a powerful tool for cell-based treatment of degenerative diseases, including diabetes mellitus. To determine which, if any, adult tissues are competent to activate an islet β cell program, we performed an in vivo screen by expressing three β cell “reprogramming factors” in a wide spectrum of tissues. We report that transient intestinal expression of these factors—Pdx1, MafA, and Ngn3 (PMN—promotes rapid conversion of intestinal crypt cells into endocrine cells, which coalesce into “neoislets” below the crypt base. Neoislet cells express insulin and show ultrastructural features of β cells. Importantly, intestinal neoislets are glucose-responsive and able to ameliorate hyperglycemia in diabetic mice. Moreover, PMN expression in human intestinal “organoids” stimulates the conversion of intestinal epithelial cells into β-like cells. Our results thus demonstrate that the intestine is an accessible and abundant source of functional insulin-producing cells.

  5. Application of Three-Dimensional Imaging to the Intestinal Crypt Organoids and Biopsied Intestinal Tissues

    Directory of Open Access Journals (Sweden)

    Yun Chen

    2013-01-01

    Full Text Available Two-dimensional (2D histopathology is the standard analytical method for intestinal biopsied tissues; however, the role of 3-dimensional (3D imaging system in the analysis of the intestinal tissues is unclear. The 3D structure of the crypt organoids from the intestinal stem cell culture and intestinal tissues from the donors and recipients after intestinal transplantation was observed using a 3D imaging system and compared with 2D histopathology and immunohistochemistry. The crypt organoids and intestinal tissues showed well-defined 3D structures. The 3D images of the intestinal tissues with acute rejection revealed absence of villi and few crypts, which were consistent with the histopathological features. In the intestinal transplant for megacystis microcolon intestinal hypoperistalsis syndrome, the donor’s intestinal tissues had well-developed nerve networks and interstitial cells of Cajal (ICCs in the muscle layer, while the recipient’s intestinal tissues had distorted nerve network and the ICCs were few and sparsely distributed, relative to those of the donor. The 3D images showed a clear spatial relationship between the microstructures of the small bowel and the features of graft rejection. In conclusion, integration of the 3D imaging and 2D histopathology provided a global view of the intestinal tissues from the transplant patients.

  6. IGF1 stimulates crypt expansion via differential activation of 2 intestinal stem cell populations.

    Science.gov (United States)

    Van Landeghem, Laurianne; Santoro, M Agostina; Mah, Amanda T; Krebs, Adrienne E; Dehmer, Jeffrey J; McNaughton, Kirk K; Helmrath, Michael A; Magness, Scott T; Lund, P Kay

    2015-07-01

    Insulin-like growth factor 1 (IGF1) has potent trophic effects on normal or injured intestinal epithelium, but specific effects on intestinal stem cells (ISCs) are undefined. We used Sox9-enhanced green fluorescent protein (EGFP) reporter mice that permit analyses of both actively cycling ISCs (Sox9-EGFP(Low)) and reserve/facultative ISCs (Sox9-EGFP(High)) to study IGF1 action on ISCs in normal intestine or during crypt regeneration after high-dose radiation-induced injury. We hypothesized that IGF1 differentially regulates proliferation and gene expression in actively cycling and reserve/facultative ISCs. IGF1 was delivered for 5 days using subcutaneously implanted mini-pumps in uninjured mice or after 14 Gy abdominal radiation. ISC numbers, proliferation, and transcriptome were assessed. IGF1 increased epithelial growth in nonirradiated mice and enhanced crypt regeneration after radiation. In uninjured and regenerating intestines, IGF1 increased total numbers of Sox9-EGFP(Low) ISCs and percentage of these cells in M-phase. IGF1 increased percentages of Sox9-EGFP(High) ISCs in S-phase but did not expand this population. Microarray revealed that IGF1 activated distinct gene expression signatures in the 2 Sox9-EGFP ISC populations. In vitro IGF1 enhanced enteroid formation by Sox9-EGFP(High) facultative ISCs but not Sox9-EGFP(Low) actively cycling ISCs. Our data provide new evidence that IGF1 activates 2 ISC populations via distinct regulatory pathways to promote growth of normal intestinal epithelium and crypt regeneration after irradiation.

  7. Paneth cells: maestros of the small intestinal crypts

    NARCIS (Netherlands)

    Clevers, H.C.; Bevins, C.L.

    2013-01-01

    Paneth cells are highly specialized epithelial cells of the small intestine, where they coordinate many physiological functions. First identified more than a century ago on the basis of their readily discernible secretory granules by routine histology, these cells are located at the base of the cryp

  8. Impaired Cell Volume Regulation in Intestinal Crypt Epithelia of Cystic Fibrosis Mice

    Science.gov (United States)

    Valverde, M. A.; O'Brien, J. A.; Sepulveda, F. V.; Ratcliff, R. A.; Evans, M. J.; Colledge, W. H.

    1995-09-01

    Cystic fibrosis is a disease characterized by abnormalities in the epithelia of the lungs, intestine, salivary and sweat glands, liver, and reproductive systems, often as a result of inadequate hydration of their secretions. The primary defect in cystic fibrosis is the altered activity of a cAMP-activated Cl^- channel, the cystic fibrosis transmembrane conductance regulator (CFTR) channel. However, it is not clear how a defect in the CFTR Cl^- channel function leads to the observed pathological changes. Although much is known about the structural properties and regulation of the CFTR, little is known of its relationship to cellular functions other than the cAMP-dependent Cl^- secretion. Here we report that cell volume regulation after hypotonic challenge is also defective in intestinal crypt epithelial cells isolated from CFTR -/- mutant mice. Moreover, the impairment of the regulatory volume decrease in CFTR -/- crypts appears to be related to the inability of a K^+ conductance to provide a pathway for the exit of this cation during the volume adjustments. This provides evidence that the lack of CFTR protein may have additional consequences for the cellular function other than the abnormal cAMP-mediated Cl^- secretion.

  9. Notch/gamma-secretase inhibition turns proliferative cells in intestinal crypts and adenomas into goblet cells.

    NARCIS (Netherlands)

    Es, J.H. van; Gijn, M.E. van; Riccio, O.; Born, M. van den; Vooijs, M.; Begthel, H.; Cozijnsen, M.; Robine, S.; Winston, D.J.; Radtke, F.; Clevers, J.C.

    2005-01-01

    The self-renewing epithelium of the small intestine is ordered into stem/progenitor crypt compartments and differentiated villus compartments. Recent evidence indicates that the Wnt cascade is the dominant force in controlling cell fate along the crypt-villus axis. Here we show a rapid, massive

  10. Paneth cells constitute the niche for Lgr5 stem cells in intestinal crypts

    NARCIS (Netherlands)

    Sato, T.; van Es, J.H.; Snippert, H.J.G.; Stange, D.E.; Vries, R.G.J.; van den Born, M.M.W.; Barker, N.; Shroyer, N.F.; van de Wetering, M.L.; Clevers, H.

    2010-01-01

    Homeostasis of self-renewing small intestinal crypts results from neutral competition between Lgr5 stem cells, which are small cycling cells located at crypt bottoms. Lgr5 stem cells are interspersed between terminally differentiated Paneth cells that are known to produce bactericidal products such

  11. Notch/gamma-secretase inhibition turns proliferative cells in intestinal crypts and adenomas into goblet cells.

    NARCIS (Netherlands)

    Es, J.H. van; Gijn, M.E. van; Riccio, O.; Born, M. van den; Vooijs, M.; Begthel, H.; Cozijnsen, M.; Robine, S.; Winston, D.J.; Radtke, F.; Clevers, J.C.

    2005-01-01

    The self-renewing epithelium of the small intestine is ordered into stem/progenitor crypt compartments and differentiated villus compartments. Recent evidence indicates that the Wnt cascade is the dominant force in controlling cell fate along the crypt-villus axis. Here we show a rapid, massive conv

  12. Reg4+ deep crypt secretory cells function as epithelial niche for Lgr5+ stem cells in colon

    NARCIS (Netherlands)

    Sasaki, Nobuo; Sachs, Norman; Wiebrands, Kay; Ellenbroek, Saskia I J; Fumagalli, Arianna; Lyubimova, Anna; Begthel, Harry; van den Born, Maaike; van Es, Johan H; Karthaus, Wouter R; Li, Vivian S W; López-Iglesias, Carmen; Peters, Peter J; van Rheenen, Jacco; van Oudenaarden, Alexander; Clevers, Hans

    2016-01-01

    Leucine-rich repeat-containing G-protein coupled receptor 5-positive (Lgr5(+)) stem cells reside at crypt bottoms of the small and large intestine. Small intestinal Paneth cells supply Wnt3, EGF, and Notch signals to neighboring Lgr5(+) stem cells. Whereas the colon lacks Paneth cells, deep crypt

  13. Bone marrow hypoplasia and intestinal crypt cell necrosis associated with fenbendazole administration in five painted storks.

    Science.gov (United States)

    Weber, Martha A; Terrell, Scott P; Neiffer, Donald L; Miller, Michele A; Mangold, Barbara J

    2002-08-01

    Five painted storks were treated with fenbendazole for 5 days for internal parasitism. Four birds died following treatment. Profound heteropenia was a consistent finding in all samples evaluated; additionally, the 1 surviving bird had progressive anemia. Consistent necropsy findings in the 4 birds that died were small intestinal crypt cell necrosis and severe bone marrow depletion and necrosis. Fenbendazole has been associated with bone marrow hypoplasia and enteric damage in mammals and other species of birds. The dosages of fenbendazole used in birds are often substantially higher than those recommended for mammals, which may contribute to bone marrow hypoplasia and intestinal crypt cell necrosis associated with fenbendazole administration in birds.

  14. Changes in the transcriptional profile of transporters in the intestine along the anterior-posterior and crypt-villus axes

    Directory of Open Access Journals (Sweden)

    Delorenzi Mauro

    2005-05-01

    Full Text Available Abstract Background The purpose of this work was to characterize the expression of drug and nutrient carriers along the anterior-posterior and crypt-villus axes of the intestinal epithelium and to study the validity of utilizing whole gut tissue rather than purified epithelial cells to examine regional variations in gene expression. Results We have characterized the mRNA expression profiles of 76 % of all currently known transporters along the anterior-posterior axis of the gut. This is the first study to describe the expression profiles of the majority of all known transporters in the intestine. The expression profiles of transporters, as defined according to the Gene Ontology consortium, were measured in whole tissue of the murine duodenum, jejunum, ileum and colon using high-density microarrays. For nine transporters (Abca1, Abcc1, Abcc3, Abcg8, Slc10a2, Slc28a2, Slc2a1, Slc34a2 and Slc5a8, the mRNA profiles were further measured by RT-PCR in laser micro-dissected crypt and villus epithelial cells corresponding to the aforementioned intestinal regions. With respect to differentially regulated transporters, the colon had a distinct expression profile from small intestinal segments. The majority (59 % for p cutoff ≤ 0.05 of transporter mRNA levels were constant across the intestinal sections studied. For the transporter subclass "carrier activity", which contains the majority of known carriers for biologically active compounds, a significant change (p ≤ 0.05 along the anterior-posterior axis was observed. Conclusion All nine transporters examined in laser-dissected material demonstrated good replication of the region-specific profiles revealed by microarray. Furthermore, we suggest that the distribution characteristics of Slc5a8 along the intestinal tract render it a suitable candidate carrier for monocarboxylate drugs in the posterior portion of the intestine. Our findings also predict that there is a significant difference in the

  15. Crypt base columnar stem cells in small intestines of mice are radioresistant

    NARCIS (Netherlands)

    Hua, G.; Thin, T.H.; Feldman, R.; Haimovitz-Friedman, A.; Clevers, H.; Fuks, Z.; Kolesnick, R.

    2012-01-01

    BACKGROUND & AIMS: Adult stem cells have been proposed to be quiescent and radiation resistant, repairing DNA double-strand breaks by nonhomologous end joining. However, the population of putative small intestinal stem cells (ISCs) at position +4 from the crypt base contradicts this model, in that t

  16. Intestinal crypt homeostasis revealed at single-stem-cell level by in vivo live imaging

    Science.gov (United States)

    Ritsma, Laila; Ellenbroek, Saskia I. J.; Zomer, Anoek; Snippert, Hugo J.; de Sauvage, Frederic J.; Simons, Benjamin D.; Clevers, Hans; van Rheenen, Jacco

    2014-03-01

    The rapid turnover of the mammalian intestinal epithelium is supported by stem cells located around the base of the crypt. In addition to the Lgr5 marker, intestinal stem cells have been associated with other markers that are expressed heterogeneously within the crypt base region. Previous quantitative clonal fate analyses have led to the proposal that homeostasis occurs as the consequence of neutral competition between dividing stem cells. However, the short-term behaviour of individual Lgr5+ cells positioned at different locations within the crypt base compartment has not been resolved. Here we establish the short-term dynamics of intestinal stem cells using the novel approach of continuous intravital imaging of Lgr5-Confetti mice. We find that Lgr5+ cells in the upper part of the niche (termed `border cells') can be passively displaced into the transit-amplifying domain, after the division of proximate cells, implying that the determination of stem-cell fate can be uncoupled from division. Through quantitative analysis of individual clonal lineages, we show that stem cells at the crypt base, termed `central cells', experience a survival advantage over border stem cells. However, through the transfer of stem cells between the border and central regions, all Lgr5+ cells are endowed with long-term self-renewal potential. These findings establish a novel paradigm for stem-cell maintenance in which a dynamically heterogeneous cell population is able to function long term as a single stem-cell pool.

  17. A reaction–diffusion mechanism influences cell lineage progression as a basis for formation, regeneration, and stability of intestinal crypts

    Directory of Open Access Journals (Sweden)

    Zhang Lei

    2012-07-01

    Full Text Available Abstract Background Colon crypts, a single sheet of epithelia cells, consist of a periodic pattern of stem cells, transit-amplifying cells, and terminally differentiated cells that constantly renew and turnover. Experimental evidence suggests that Wnt signaling promotes and regulates stem cell division, differentiation, and possible cell migrations while intestinal BMP signaling inhibits stem cell self-renewal and repression in crypt formation. As more molecular details on Wnt and BMP in crypts are being discovered, little is still known about how complex interactions among Wnt, BMP, and different types of cells, and surrounding environments may lead to de novo formation of multiple crypts or how such interactions affect regeneration and stability of crypts. Results We present a mathematical model that contains Wnt and BMP, a cell lineage, and their feedback regulations to study formation, regeneration, and stability of multiple crypts. The computational explorations and linear stability analysis of the model suggest a reaction–diffusion mechanism, which exhibits a short-range activation of Wnt plus a long-range inhibition with modulation of BMP signals in a growing tissue of cell lineage, can account for spontaneous formation of multiple crypts with the spatial and temporal pattern observed in experiments. Through this mechanism, the model can recapitulate some distinctive and important experimental findings such as crypt regeneration and crypt multiplication. BMP is important in maintaining stability of crypts and loss of BMP usually leads to crypt multiplication with a fingering pattern. Conclusions The study provides a mechanism for de novo formation of multiple intestinal crypts and demonstrates a synergetic role of Wnt and BMP in regeneration and stability of intestinal crypts. The proposed model presents a robust framework for studying spatial and temporal dynamics of cell lineages in growing tissues driven by multiple signaling

  18. Stem cell self-renewal in intestinal crypt

    NARCIS (Netherlands)

    Simons, B.D.; Clevers, H.

    2011-01-01

    As a rapidly cycling tissue capable of fast repair and regeneration, the intestinal epithelium has emerged as a favored model system to explore the principles of adult stem cell biology. However, until recently, the identity and characteristics of the stem cell population in both the small intestine

  19. Stem cell self-renewal in intestinal crypt

    NARCIS (Netherlands)

    Simons, B.D.; Clevers, H.

    2011-01-01

    As a rapidly cycling tissue capable of fast repair and regeneration, the intestinal epithelium has emerged as a favored model system to explore the principles of adult stem cell biology. However, until recently, the identity and characteristics of the stem cell population in both the small intestine

  20. Preferential entry of botulinum neurotoxin A Hc domain through intestinal crypt cells and targeting to cholinergic neurons of the mouse intestine.

    Directory of Open Access Journals (Sweden)

    Aurélie Couesnon

    Full Text Available Botulism, characterized by flaccid paralysis, commonly results from botulinum neurotoxin (BoNT absorption across the epithelial barrier from the digestive tract and then dissemination through the blood circulation to target autonomic and motor nerve terminals. The trafficking pathway of BoNT/A passage through the intestinal barrier is not yet fully understood. We report that intralumenal administration of purified BoNT/A into mouse ileum segment impaired spontaneous muscle contractions and abolished the smooth muscle contractions evoked by electric field stimulation. Entry of BoNT/A into the mouse upper small intestine was monitored with fluorescent HcA (half C-terminal domain of heavy chain which interacts with cell surface receptor(s. We show that HcA preferentially recognizes a subset of neuroendocrine intestinal crypt cells, which probably represent the entry site of the toxin through the intestinal barrier, then targets specific neurons in the submucosa and later (90-120 min in the musculosa. HcA mainly binds to certain cholinergic neurons of both submucosal and myenteric plexuses, but also recognizes, although to a lower extent, other neuronal cells including glutamatergic and serotoninergic neurons in the submucosa. Intestinal cholinergic neuron targeting by HcA could account for the inhibition of intestinal peristaltism and secretion observed in botulism, but the consequences of the targeting to non-cholinergic neurons remains to be determined.

  1. Analysis of the spatial and dynamical properties of a multiscale model of intestinal crypts

    Directory of Open Access Journals (Sweden)

    Marco Antoniotti

    2013-09-01

    Full Text Available The preliminary analyses on a multiscale model of intestinal crypt dynamics are here presented. The model combines a morphological model, based on the Cellular Potts Model (CPM, and a gene regulatory network model, based on Noisy Random Boolean Networks (NRBNs. Simulations suggest that the stochastic differentiation process is itself sufficient to ensure the general homeostasis in the asymptotic states, as proven by several measures.

  2. Paneth cell marker expression in intestinal villi and colon crypts characterizes dietary induced risk for mouse sporadic intestinal cancer.

    Science.gov (United States)

    Wang, Donghai; Peregrina, Karina; Dhima, Elena; Lin, Elaine Y; Mariadason, John M; Augenlicht, Leonard H

    2011-06-21

    Nutritional and genetic risk factors for intestinal tumors are additive on mouse tumor phenotype, establishing that diet and genetic factors impact risk by distinct combinatorial mechanisms. In a mouse model of dietary-induced sporadic small and large intestinal cancer in WT mice in which tumor etiology, lag, incidence, and frequency reflect >90% of intestinal cancer in Western societies, dietary-induced risk altered gene expression profiles predominantly in villus cells of the histologically normal mucosa, in contrast to targeting of crypt cells by inheritance of an Apc(1638N) allele or homozygous inactivation of p21(Waf1/cip1), and profiles induced by each risk factor were distinct at the gene or functional group level. The dietary-induced changes in villus cells encompassed ectopic expression of Paneth cell markers (a lineage normally confined to the bottom of small intestinal crypts), elevated expression of the Wnt receptor Fzd5 and of EphB2 (genes necessary for Paneth cell differentiation and localization to the crypt bottom), and increased Wnt signaling in villus cells. Ectopic elevation of these markers was also present in the colon crypts, which are also sites of sporadic tumors in the nutritional model. Elevating dietary vitamin D(3) and calcium, which prevents tumor development, abrogated these changes in the villus and colon cells. Thus, common intestinal cancer driven by diet involves mechanisms of tumor development distinct from those mechanisms that cause tumors induced by the rare inheritance of a mutant adenomatous polyposis coli (Apc) allele. This is fundamental for understanding how common sporadic tumors arise and in evaluating relative risk in the population.

  3. Dietary Pectin Increases Intestinal Crypt Stem Cell Survival following Radiation Injury.

    Directory of Open Access Journals (Sweden)

    Sripathi M Sureban

    Full Text Available Gastrointestinal (GI mucosal damage is a devastating adverse effect of radiation therapy. We have recently reported that expression of Dclk1, a Tuft cell and tumor stem cell (TSC marker, 24h after high dose total-body gamma-IR (TBI can be used as a surrogate marker for crypt survival. Dietary pectin has been demonstrated to possess chemopreventive properties, whereas its radioprotective property has not been studied. The aim of this study was to determine the effects of dietary pectin on ionizing radiation (IR-induced intestinal stem cell (ISC deletion, crypt and overall survival following lethal TBI. C57BL/6 mice received a 6% pectin diet and 0.5% pectin drinking water (pre-IR mice received pectin one week before TBI until death; post-IR mice received pectin after TBI until death. Animals were exposed to TBI (14 Gy and euthanized at 24 and 84h post-IR to assess ISC deletion and crypt survival respectively. Animals were also subjected to overall survival studies following TBI. In pre-IR treatment group, we observed a three-fold increase in ISC/crypt survival, a two-fold increase in Dclk1+ stem cells, increased overall survival (median 10d vs. 7d, and increased expression of Dclk1, Msi1, Lgr5, Bmi1, and Notch1 (in small intestine post-TBI in pectin treated mice compared to controls. We also observed increased survival of mice treated with pectin (post-IR compared to controls. Dietary pectin is a radioprotective agent; prevents IR-induced deletion of potential reserve ISCs; facilitates crypt regeneration; and ultimately promotes overall survival. Given the anti-cancer activity of pectin, our data support a potential role for dietary pectin as an agent that can be administered to patients receiving radiation therapy to protect against radiation-induces mucositis.

  4. Dietary Pectin Increases Intestinal Crypt Stem Cell Survival following Radiation Injury.

    Science.gov (United States)

    Sureban, Sripathi M; May, Randal; Qu, Dongfeng; Chandrakesan, Parthasarathy; Weygant, Nathaniel; Ali, Naushad; Lightfoot, Stan A; Ding, Kai; Umar, Shahid; Schlosser, Michael J; Houchen, Courtney W

    2015-01-01

    Gastrointestinal (GI) mucosal damage is a devastating adverse effect of radiation therapy. We have recently reported that expression of Dclk1, a Tuft cell and tumor stem cell (TSC) marker, 24h after high dose total-body gamma-IR (TBI) can be used as a surrogate marker for crypt survival. Dietary pectin has been demonstrated to possess chemopreventive properties, whereas its radioprotective property has not been studied. The aim of this study was to determine the effects of dietary pectin on ionizing radiation (IR)-induced intestinal stem cell (ISC) deletion, crypt and overall survival following lethal TBI. C57BL/6 mice received a 6% pectin diet and 0.5% pectin drinking water (pre-IR mice received pectin one week before TBI until death; post-IR mice received pectin after TBI until death). Animals were exposed to TBI (14 Gy) and euthanized at 24 and 84h post-IR to assess ISC deletion and crypt survival respectively. Animals were also subjected to overall survival studies following TBI. In pre-IR treatment group, we observed a three-fold increase in ISC/crypt survival, a two-fold increase in Dclk1+ stem cells, increased overall survival (median 10d vs. 7d), and increased expression of Dclk1, Msi1, Lgr5, Bmi1, and Notch1 (in small intestine) post-TBI in pectin treated mice compared to controls. We also observed increased survival of mice treated with pectin (post-IR) compared to controls. Dietary pectin is a radioprotective agent; prevents IR-induced deletion of potential reserve ISCs; facilitates crypt regeneration; and ultimately promotes overall survival. Given the anti-cancer activity of pectin, our data support a potential role for dietary pectin as an agent that can be administered to patients receiving radiation therapy to protect against radiation-induces mucositis.

  5. Prostaglandin-induced radioprotection of murine intestinal crypts and villi by a PGE diene analog (SC-44932) and a PGI analog (Iloprost)

    Science.gov (United States)

    Hanson, Wayne R.; Collins, Paul W.

    The aminothiols exemplified by WR-2721 are effective radioprotectors; however, their toxicity associated with hypotension, nausea, and emesis has limited their development for applications in medicine or in hazardous radiation environments. There is a need for new radioprotectors that have fewer toxic side effects when given alone or combined with reduced amounts of thiols. A variety of prostaglandins (PGs) have been shown to be radioprotective agents and some appear to have fewer toxic side effects than the aminothiols. Iloprost, a stable PGI, analog protects the clonogenic epithelial cells of intestinal crypts but does not protect epithelial cells of the villi. In contrast, an E-series omega chain diene analog designated SC-44932 protects epithelial cells of both crypts and villi. When the two are combined, protection of the crypts is additive and the villi are protected to the same degree as when SC-44932 is given alone. Since radioprotection for some PGs has been shown to be dependent upon receptors, we suggest that the pattern of radioprotection seen with these two analogs depend on the location of the respective receptors or on the ability of differentiated villus cells to respond to PGs. By studying different analogs, we hope to identify mechanisms associated with PG-induced radioprotection and to identify the most protective PG analogs for applications of radioprotection.

  6. CD44 and TLR4 mediate hyaluronic acid regulation of Lgr5+ stem cell proliferation, crypt fission, and intestinal growth in postnatal and adult mice.

    Science.gov (United States)

    Riehl, Terrence E; Santhanam, Srikanth; Foster, Lynne; Ciorba, Matthew; Stenson, William F

    2015-12-01

    Hyaluronic acid, a glycosaminoglycan in the extracellular matrix, binds to CD44 and Toll-like receptor 4 (TLR4). We previously addressed the role of hyaluronic acid in small intestinal and colonic growth in mice. We addressed the role of exogenous hyaluronic acid by giving hyaluronic acid intraperitoneally and the role of endogenous hyaluronic acid by giving PEP-1, a peptide that blocks hyaluronic acid binding to its receptors. Exogenous hyaluronic acid increased epithelial proliferation but had no effect on intestinal length. PEP-1 resulted in a shortened small intestine and colon and diminished epithelial proliferation. In the current study, we sought to determine whether the effects of hyaluronic acid on growth were mediated by signaling through CD44 or TLR4 by giving exogenous hyaluronic acid or PEP-1 twice a week from 3-8 wk of age to wild-type, CD44(-/-), and TLR4(-/-) mice. These studies demonstrated that signaling through both CD44 and TLR4 were important in mediating the effects of hyaluronic acid on growth in the small intestine and colon. Extending our studies to early postnatal life, we assessed the effects of exogenous hyaluronic acid and PEP-1 on Lgr5(+) stem cell proliferation and crypt fission. Administration of PEP-1 to Lgr5(+) reporter mice from postnatal day 7 to day 14 decreased Lgr5(+) cell proliferation and decreased crypt fission. These studies indicate that endogenous hyaluronic acid increases Lgr5(+) stem cell proliferation, crypt fission, and intestinal lengthening and that these effects are dependent on signaling through CD44 and TLR4.

  7. Type 3 innate lymphoid cells maintain intestinal epithelial stem cells after tissue damage.

    Science.gov (United States)

    Aparicio-Domingo, Patricia; Romera-Hernandez, Monica; Karrich, Julien J; Cornelissen, Ferry; Papazian, Natalie; Lindenbergh-Kortleve, Dicky J; Butler, James A; Boon, Louis; Coles, Mark C; Samsom, Janneke N; Cupedo, Tom

    2015-10-19

    Disruption of the intestinal epithelial barrier allows bacterial translocation and predisposes to destructive inflammation. To ensure proper barrier composition, crypt-residing stem cells continuously proliferate and replenish all intestinal epithelial cells within days. As a consequence of this high mitotic activity, mucosal surfaces are frequently targeted by anticancer therapies, leading to dose-limiting side effects. The cellular mechanisms that control tissue protection and mucosal healing in response to intestinal damage remain poorly understood. Type 3 innate lymphoid cells (ILC3s) are regulators of homeostasis and tissue responses to infection at mucosal surfaces. We now demonstrate that ILC3s are required for epithelial activation and proliferation in response to small intestinal tissue damage induced by the chemotherapeutic agent methotrexate. Multiple subsets of ILC3s are activated after intestinal tissue damage, and in the absence of ILC3s, epithelial activation is lost, correlating with increased pathology and severe damage to the intestinal crypts. Using ILC3-deficient Lgr5 reporter mice, we show that maintenance of intestinal stem cells after damage is severely impaired in the absence of ILC3s or the ILC3 signature cytokine IL-22. These data unveil a novel function of ILC3s in limiting tissue damage by preserving tissue-specific stem cells.

  8. Intestinal alkaline phosphatase contributes to the reduction of severe intestinal epithelial damage.

    Science.gov (United States)

    Bol-Schoenmakers, Marianne; Fiechter, Daniëlle; Raaben, Willem; Hassing, Ine; Bleumink, Rob; Kruijswijk, Daniëlle; Maijoor, Kelly; Tersteeg-Zijderveld, Monique; Brands, Ruud; Pieters, Raymond

    2010-05-10

    Inflammatory bowel disease is characterized by chronic inflammation of the intestine and is accompanied by damage of the epithelial lining and by undesired immune responses towards enteric bacteria. It has been demonstrated that intestinal alkaline phosphatase (iAP) protects against the induction of inflammation, possibly due to dephosphorylation of lipopolysaccharide (LPS). The present study investigated the therapeutic potential of iAP in intestinal inflammation and epithelial damage. Intestinal epithelial damage was induced in C57BL/6 mice using detran sulfate sodium (DSS) and iAP was administered 4days after initial DSS exposure. Loss in body weight was significantly less in iAP-treated mice and accompanied with reduced colon damage (determined by combination of crypt loss, loss of goblet cells, oedema and infiltrations of neutrophils). Treatment with iAP was more effective in case of severe inflammation compared to situations of mild to moderate inflammation. Rectal administration of LPS into a moderate inflamed colon did not aggravate inflammation. Furthermore, soluble iAP did not lower LPS-induced nuclear factor-kappaB activation in epithelial cells in vitro but induction of cellular AP expression by butyrate resulted in decreased LPS response. In conclusion, the present study shows that oral iAP administration has beneficial effects in situations of severe intestinal epithelial damage, whereas in moderate inflammation endogenous iAP may be sufficient to counteract disease-aggravating effects of LPS. An approach including iAP treatment holds a therapeutic promise in case of severe inflammatory bowel disease. Copyright 2010 Elsevier B.V. All rights reserved.

  9. Intestinal epithelial cells in inflammatory bowel diseases

    Institute of Scientific and Technical Information of China (English)

    Giulia; Roda; Alessandro; Sartini; Elisabetta; Zambon; Andrea; Calafiore; Margherita; Marocchi; Alessandra; Caponi; Andrea; Belluzzi; Enrico; Roda

    2010-01-01

    The pathogenesis of inflammatory bowel diseases (IBDs) seems to involve a primary defect in one or more of the elements responsible for the maintenance of intestinal homeostasis and oral tolerance. The most important element is represented by the intestinal barrier, a complex system formed mostly by intestinal epithelial cells (IECs). IECs have an active role in producing mucus and regulating its composition; they provide a physical barrier capable of controlling antigen traff ic through the intestinal muco...

  10. Fibroblast growth factor receptor-3 regulates Paneth cell lineage allocation and accrual of epithelial stem cells during murine intestinal development.

    Science.gov (United States)

    Vidrich, Alda; Buzan, Jenny M; Brodrick, Brooks; Ilo, Chibuzo; Bradley, Leigh; Fendig, Kirstin Skaar; Sturgill, Thomas; Cohn, Steven M

    2009-07-01

    Fibroblast growth factor receptor 3 (FGFR-3) is expressed in the lower crypt epithelium, where stem cells of the intestine reside. The role of FGFR-3 signaling in regulating features of intestinal morphogenesis was examined in FGFR-3-null (FGFR-3(-/-)) mice. FGFR-3(-/-) mice had only about half the number of intestinal crypts and a marked decrease in the number of functional clonogenic stem cells, as assessed by an in vivo microcolony-forming assay, compared with wild-type littermates. A marked deficit in allocation of progenitor cells to Paneth cell differentiation was noted, although all the principal epithelial lineages were represented in FGFR-3(-/-) mice. The total cellular content and nuclear localization of beta-catenin protein were reduced in FGFR-3(-/-) mice, as was expression of cyclin D1 and matrix metalloproteinase-7, major downstream targets of beta-catenin/T cell factor-4 (Tcf-4) signaling. Activation of FGFR-3 in Caco-2 cells, an intestinal epithelial cell line, abrogated the fall in beta-catenin/Tcf-4 signaling activity that is normally observed in these cells as cultures become progressively more confluent. These findings are consistent with the hypothesis that, during intestinal development, FGFR-3 signaling regulates crypt epithelial stem cell expansion and crypt morphogenesis, as well as Paneth cell lineage specification, through beta-catenin/Tcf-4-dependent and -independent pathways.

  11. Wound healing of intestinal epithelial cells

    Institute of Scientific and Technical Information of China (English)

    Masahiro Iizuka; Shiho Konno

    2011-01-01

    The intestinal epithelial cells (IECs) form a selective permeability barrier separating luminal content from underlying tissues. Upon injury, the intestinal epithelium undergoes a wound healing process. Intestinal wound healing is dependent on the balance of three cellular events;restitution, proliferation, and differentiation of epithelial cells adjacent to the wounded area. Previous studies have shown that various regulatory peptides, including growth factors and cytokines, modulate intestinal epithelial wound healing. Recent studies have revealed that novel factors, which include toll-like receptors (TLRs), regulatory peptides, particular dietary factors, and some gastroprotective agents, also modulate intestinal epithelial wound repair. Among these factors, the activation of TLRs by commensal bacteria is suggested to play an essential role in the maintenance of gut homeostasis. Recent studies suggest that mutations and dysregulation of TLRs could be major contributing factors in the predisposition and perpetuation of inflammatory bowel disease. Additionally, studies have shown that specific signaling pathways are involved in IEC wound repair. In this review, we summarize the function of IECs, the process of intestinal epithelial wound healing, and the functions and mechanisms of the various factors that contribute to gut homeostasis and intestinal epithelial wound healing.

  12. Transgenic Expression of Human Lysophosphatidic Acid Receptor LPA2 in Mouse Intestinal Epithelial Cells Induces Intestinal Dysplasia.

    Directory of Open Access Journals (Sweden)

    Michihiro Yoshida

    Full Text Available Lysophosphatidic acid (LPA acts on LPA2 receptor to mediate multiple pathological effects that are associated with tumorigenesis. The absence of LPA2 attenuates tumor progression in rodent models of colorectal cancer, but whether overexpression of LPA2 alone can lead to malignant transformation in the intestinal tract has not been studied. In this study, we expressed human LPA2 in intestinal epithelial cells (IECs under control of the villin promoter. Less than 4% of F1-generation mice had germline transmission of transgenic (TG human LPA2; as such only 3 F1 mice out of 72 genotyped had TG expression. These TG mice appeared anemic with hematochezia and died shortly after birth. TG mice were smaller in size compared with the wild type mouse of the same age and sex. Morphological analysis showed that TG LPA2 colon had hyper-proliferation of IECs resulting in increased colonic crypt depth. Surprisingly, TG small intestine had villus blunting and decreased IEC proliferation and dysplasia. In both intestine and colon, TG expression of LPA2 compromised the terminal epithelial differentiation, consistent with epithelial dysplasia. Furthermore, we showed that epithelial dysplasia was observed in founder mouse intestine, correlating LPA2 overexpression with epithelial dysplasia. The current study demonstrates that overexpression of LPA2 alone can lead to intestinal dysplasia.

  13. Wnt signaling: its transcriptional output in the intestinal crypt and in colon cancer

    NARCIS (Netherlands)

    Oving, I.M.

    2007-01-01

    The transition of an intestinal epithelial cell into a fully transformed, metastatic cancer cell requires mutations in multiple proto-oncogenes and key tumor suppressor genes, including those of the Wnt pathway. We describe a large scale analysis of the downstream genetic program activated by wnt si

  14. Kruppel-like factor 4 regulates intestinal epithelial cell morphology and polarity.

    Directory of Open Access Journals (Sweden)

    Tianxin Yu

    Full Text Available Krüppel-like factor 4 (KLF4 is a zinc finger transcription factor that plays a vital role in regulating cell lineage differentiation during development and maintaining epithelial homeostasis in the intestine. In normal intestine, KLF4 is predominantly expressed in the differentiated epithelial cells. It has been identified as a tumor suppressor in colorectal cancer. KLF4 knockout mice demonstrated a decrease in number of goblet cells in the colon, and conditional ablation of KLF4 from the intestinal epithelium led to altered epithelial homeostasis. However, the role of KLF4 in differentiated intestinal cells and colon cancer cells, as well as the mechanism by which it regulates homeostasis and represses tumorigenesis in the intestine is not well understood. In our study, KLF4 was partially depleted in the differentiated intestinal epithelial cells by a tamoxifen-inducible Cre recombinase. We found a significant increase in the number of goblet cells in the KLF4-deleted small intestine, suggesting that KLF4 is not only required for goblet cell differentiation, but also required for maintaining goblet cell numbers through its function in inhibiting cell proliferation. The number and position of Paneth cells also changed. This is consistent with the KLF4 knockout study using villin-Cre [1]. Through immunohistochemistry (IHC staining and statistical analysis, we found that a stem cell and/or tuft cell marker, DCAMKL1, and a proliferation marker, Ki67, are affected by KLF4 depletion, while an enteroendocrine cell marker, neurotensin (NT, was not affected. In addition, we found KLF4 depletion altered the morphology and polarity of the intestinal epithelial cells. Using a three-dimensional (3D intestinal epithelial cyst formation assay, we found that KLF4 is essential for cell polarity and crypt-cyst formation in human colon cancer cells. These findings suggest that, as a tumor suppressor in colorectal cancer, KLF4 affects intestinal epithelial cell

  15. Structural alteration of tight and adherens junctions in villous and crypt epithelium of the small and large intestine of conventional nursing piglets infected with porcine epidemic diarrhea virus.

    Science.gov (United States)

    Jung, Kwonil; Eyerly, Bryan; Annamalai, Thavamathi; Lu, Zhongyan; Saif, Linda J

    2015-06-12

    Integrity of the intestinal epithelium is critical for proper functioning of the barrier that regulates absorption of water and restricts uptake of luminal bacteria. It is maintained mainly by tight junctions (TJs) and adherens junctions (AJs). We conducted immunofluorescence (IF) staining for in situ identification of zonula occludin (ZO)-1 proteins for TJ and E-Cadherin proteins for AJ in the small and large intestinal villous and crypt epithelium of nursing pigs infected with porcine epidemic diarrhea virus (PEDV). Twenty 9-day-old piglets [PEDV-infected (n=9) and Mock (n=11)] from PEDV seronegative sows, were orally inoculated [8.9 log₁₀ genomic equivalents/pig] with PEDV PC21A strain or mock. At post-inoculation days (PIDs) 1-5, infected pigs showed severe watery diarrhea and/or vomiting and severe atrophic enteritis. By immunohistochemistry, PEDV antigens were evident in enterocytes lining the villous epithelium. At PIDs 1-5, PEDV-infected pigs exhibited mildly to extensively disorganized, irregular distribution and reduced expression of ZO-1 or E-Cadherin in villous, but not crypt epithelial cells of the jejunum and ileum, but not in the large intestine, when compared to the negative controls. The structural destruction and disorganization of TJ and AJ were extensive in PEDV-infected pigs at PIDs 1-3, but then appeared to reversibly recover at PID 5, as evident by increased numbers of ZO-1-positive epithelial cells and markedly improved appearance of E-Cadherin-positive villous epithelium. Our results suggest a possible involvement of structurally impaired TJ and AJ in the pathogenesis of PEDV, potentially leading to secondary bacterial infections.

  16. Intestinal epithelial stem/progenitor cells are controlled by mucosal afferent nerves.

    Directory of Open Access Journals (Sweden)

    Ove Lundgren

    Full Text Available BACKGROUND: The maintenance of the intestinal epithelium is of great importance for the survival of the organism. A possible nervous control of epithelial cell renewal was studied in rats and mice. METHODS: Mucosal afferent nerves were stimulated by exposing the intestinal mucosa to capsaicin (1.6 mM, which stimulates intestinal external axons. Epithelial cell renewal was investigated in the jejunum by measuring intestinal thymidine kinase (TK activity, intestinal (3H-thymidine incorporation into DNA, and the number of crypt cells labeled with BrdU. The influence of the external gut innervation was minimized by severing the periarterial nerves. PRINCIPAL FINDINGS: Luminal capsaicin increased all the studied variables, an effect nervously mediated to judge from inhibitory effects on TK activity or (3H-thymidine incorporation into DNA by exposing the mucosa to lidocaine (a local anesthetic or by giving four different neurotransmitter receptor antagonists i.v. (muscarinic, nicotinic, neurokinin1 (NK1 or calcitonin gene related peptide (CGRP receptors. After degeneration of the intestinal external nerves capsaicin did not increase TK activity, suggesting the involvement of an axon reflex. Intra-arterial infusion of Substance P (SP or CGRP increased intestinal TK activity, a response abolished by muscarinic receptor blockade. Immunohistochemistry suggested presence of M3 and M5 muscarinic receptors on the intestinal stem/progenitor cells. We propose that the stem/progenitor cells are controlled by cholinergic nerves, which, in turn, are influenced by mucosal afferent neuron(s releasing acetylcholine and/or SP and/or CGRP. In mice lacking the capsaicin receptor, thymidine incorporation into DNA and number of crypt cells labeled with BrdU was lower than in wild type animals suggesting that nerves are important also in the absence of luminal capsaicin, a conclusion also supported by the observation that atropine lowered thymidine incorporation into DNA

  17. Expansion of intestinal epithelial stem cells during murine development.

    Directory of Open Access Journals (Sweden)

    Jeffrey J Dehmer

    Full Text Available Murine small intestinal crypt development is initiated during the first postnatal week. Soon after formation, overall increases in the number of crypts occurs through a bifurcating process called crypt fission, which is believed to be driven by developmental increases in the number of intestinal stem cells (ISCs. Recent evidence suggests that a heterogeneous population of ISCs exists within the adult intestine. Actively cycling ISCs are labeled by Lgr5, Ascl2 and Olfm4; whereas slowly cycling or quiescent ISC are marked by Bmi1 and mTert. The goal of this study was to correlate the expression of these markers with indirect measures of ISC expansion during development, including quantification of crypt fission and side population (SP sorting. Significant changes were observed in the percent of crypt fission and SP cells consistent with ISC expansion between postnatal day 14 and 21. Quantitative real-time polymerase chain reaction (RT-PCR for the various ISC marker mRNAs demonstrated divergent patterns of expression. mTert surged earliest, during the first week of life as crypts are initially being formed, whereas Lgr5 and Bmi1 peaked on day 14. Olfm4 and Ascl2 had variable expression patterns. To assess the number and location of Lgr5-expressing cells during this period, histologic sections from intestines of Lgr5-EGFP mice were subjected to quantitative analysis. There was attenuated Lgr5-EGFP expression at birth and through the first week of life. Once crypts were formed, the overall number and percent of Lgr5-EGFP positive cells per crypt remain stable throughout development and into adulthood. These data were supported by Lgr5 in situ hybridization in wild-type mice. We conclude that heterogeneous populations of ISCs are expanding as measured by SP sorting and mRNA expression at distinct developmental time points.

  18. MicroRNA mir-16 is anti-proliferative in enterocytes and exhibits diurnal rhythmicity in intestinal crypts

    Energy Technology Data Exchange (ETDEWEB)

    Balakrishnan, Anita, E-mail: anita.balakrishnan@doctors.org.uk [Department of Surgery, Brigham and Women' s Hospital, Boston, MA 02115 (United States); Department of Surgery, Harvard Medical School, Boston, MA 02115 (United States); School of Clinical Sciences, Division of Gastroenterology, University of Liverpool, Liverpool L69 3GE (United Kingdom); Stearns, Adam T. [Department of Surgery, Brigham and Women' s Hospital, Boston, MA 02115 (United States); Department of Surgery, Harvard Medical School, Boston, MA 02115 (United States); Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 2JD (United Kingdom); Park, Peter J. [Department of Medicine, Brigham and Women' s Hospital, Boston, MA 02115 (United States); Harvard Medical School, Center for Biomedical Informatics, Boston, MA 02115 (United States); Dreyfuss, Jonathan M. [Department of Medicine, Brigham and Women' s Hospital, Boston, MA 02115 (United States); Ashley, Stanley W. [Department of Surgery, Brigham and Women' s Hospital, Boston, MA 02115 (United States); Department of Surgery, Harvard Medical School, Boston, MA 02115 (United States); Rhoads, David B. [Department of Surgery, Harvard Medical School, Boston, MA 02115 (United States); Pediatric Endocrine Unit, MassGeneral Hospital for Children, Boston, MA 02114 (United States); Tavakkolizadeh, Ali, E-mail: atavakkoli@partners.org [Department of Surgery, Brigham and Women' s Hospital, Boston, MA 02115 (United States); Department of Surgery, Harvard Medical School, Boston, MA 02115 (United States)

    2010-12-10

    Background and aims: The intestine exhibits profound diurnal rhythms in function and morphology, in part due to changes in enterocyte proliferation. The regulatory mechanisms behind these rhythms remain largely unknown. We hypothesized that microRNAs are involved in mediating these rhythms, and studied the role of microRNAs specifically in modulating intestinal proliferation. Methods: Diurnal rhythmicity of microRNAs in rat jejunum was analyzed by microarrays and validated by qPCR. Temporal expression of diurnally rhythmic mir-16 was further quantified in intestinal crypts, villi, and smooth muscle using laser capture microdissection and qPCR. Morphological changes in rat jejunum were assessed by histology and proliferation by immunostaining for bromodeoxyuridine. In IEC-6 cells stably overexpressing mir-16, proliferation was assessed by cell counting and MTS assay, cell cycle progression and apoptosis by flow cytometry, and cell cycle gene expression by qPCR and immunoblotting. Results: mir-16 peaked 6 hours after light onset (HALO 6) with diurnal changes restricted to crypts. Crypt depth and villus height peaked at HALO 13-14 in antiphase to mir-16. Overexpression of mir-16 in IEC-6 cells suppressed specific G1/S regulators (cyclins D1-3, cyclin E1 and cyclin-dependent kinase 6) and produced G1 arrest. Protein expression of these genes exhibited diurnal rhythmicity in rat jejunum, peaking between HALO 11 and 17 in antiphase to mir-16. Conclusions: This is the first report of circadian rhythmicity of specific microRNAs in rat jejunum. Our data provide a link between anti-proliferative mir-16 and the intestinal proliferation rhythm and point to mir-16 as an important regulator of proliferation in jejunal crypts. This function may be essential to match proliferation and absorptive capacity with nutrient availability.

  19. Altered intestinal epithelial homeostasis in mice with intestine-specific deletion of the Krüppel-like factor 4 gene.

    Science.gov (United States)

    Ghaleb, Amr M; McConnell, Beth B; Kaestner, Klaus H; Yang, Vincent W

    2011-01-15

    The zinc finger transcription factor, Krüppel-like factor 4 (KLF4), is expressed in the post-mitotic, differentiated epithelial cells lining the intestinal tract and exhibits a tumor suppressive effect on intestinal tumorigenesis. Here we report a role for KLF4 in maintaining homeostasis of intestinal epithelial cells. Mice with conditional ablation of the Klf4 gene from the intestinal epithelium were viable. However, both the rates of proliferation and migration of epithelial cells were increased in the small intestine of mutant mice. In addition, the brush-border alkaline phosphatase was reduced as was expression of ephrine-B1 in the small intestine, resulting in mispositioning of Paneth cells to the upper crypt region. In the colon of mutant mice, there was a reduction of the differentiation marker, carbonic anhydrase-1, and failure of differentiation of goblet cells. Mechanistically, deletion of Klf4 from the intestine resulted in activation of genes in the Wnt pathway and reduction in expression of genes encoding regulators of differentiation. Taken together, these data provide new insights into the function of KLF4 in regulating postnatal proliferation, migration, differentiation, and positioning of intestinal epithelial cells and demonstrate an essential role for KLF4 in maintaining normal intestinal epithelial homeostasis in vivo. Copyright © 2010 Elsevier Inc. All rights reserved.

  20. Biosynthesis of intestinal microvillar proteins. Expression of aminopeptidase N along the crypt-villus axis

    DEFF Research Database (Denmark)

    Danielsen, E M

    1984-01-01

    in the crypt cells and a moderate increase of about 20% in the villus cells. Whereas the latter can possibly be ascribed to a general protective effect of dexamethasone on villus architecture, these experiments indicate that crypt cells of mucosa from adult individuals exhibit the same sensitivity...

  1. Identifying the stem cell of the intestinal crypt: strategies and pitfalls

    NARCIS (Netherlands)

    Barker, N.; van Oudenaarden, A.; Clevers, H.

    2012-01-01

    Decades ago, two nonoverlapping crypt stem cell populations were proposed: Leblond's Crypt Base Columnar (CBC) cell and Potten's +4 cell. The identification of CBC markers including Lgr5 has confirmed Leblond's predictions that CBC cells are anatomically distinct, long-lived stem cells that

  2. Identifying the stem cell of the intestinal crypt: strategies and pitfalls

    NARCIS (Netherlands)

    Barker, N.; van Oudenaarden, A.; Clevers, H.

    2012-01-01

    Decades ago, two nonoverlapping crypt stem cell populations were proposed: Leblond's Crypt Base Columnar (CBC) cell and Potten's +4 cell. The identification of CBC markers including Lgr5 has confirmed Leblond's predictions that CBC cells are anatomically distinct, long-lived stem cells that permanen

  3. Intestinal epithelial apoptosis initiates gut mucosal injury during extracorporeal membrane oxygenation in the newborn piglet.

    Science.gov (United States)

    MohanKumar, Krishnan; Killingsworth, Cheryl R; McIlwain, R Britt; Timpa, Joseph G; Jagadeeswaran, Ramasamy; Namachivayam, Kopperuncholan; Kurundkar, Ashish R; Kelly, David R; Garzon, Steven A; Maheshwari, Akhil

    2014-02-01

    Neonates and young infants exposed to extracorporeal circulation during extracorporeal membrane oxygenation (ECMO) and cardiopulmonary bypass are at risk of developing a systemic inflammatory response syndrome with multi-organ dysfunction. We used a piglet model of ECMO to investigate the hypothesis that epithelial apoptosis is an early event that precedes villous damage during ECMO-related bowel injury. Healthy 3-week-old piglets were subjected to ECMO for up to 8 h. Epithelial apoptosis was measured in histopathological analysis, nuclear imaging, and terminal deoxynucleotidyl transferase dUTP nick end labeling. Plasma intestinal fatty acid-binding protein (I-FABP) levels were measured by enzyme immunoassay. Intestinal mast cells were isolated by fluorescence-assisted cell sorting. Cleaved caspase-8, caspase-9, phospho-p38 MAPK, and fas ligand expression were investigated by immunohistochemistry, western blots, and reverse transcriptase-quantitative PCR. Piglet ECMO was associated with increased gut epithelial apoptosis. Extensive apoptotic changes were noted on villus tips and in scattered crypt cells after 2 h of ECMO. After 8 h, the villi were denuded and apoptotic changes were evident in a majority of crypt cells. Increased circulating I-FABP levels, a marker of gut epithelial injury, showed that epithelial injury occurred during ECMO. We detected increased cleaved caspase-8, but not cleaved caspase-9, in epithelial cells indicating that the extrinsic apoptotic pathway was active. ECMO was associated with increased fas ligand expression in intestinal mast cells, which was induced through activation of the p38 mitogen-activated protein kinase. We conclude that epithelial apoptosis is an early event that initiates gut mucosal injury in a piglet model of ECMO.

  4. Plasticity of intestinal epithelial cells in regeneration and cancer

    NARCIS (Netherlands)

    Tetteh, P.W.

    2015-01-01

    Cellular plasticity refers to the ability of a cell to change its fate or identity in response to external or intrinsic factors. Regeneration of the intestinal epithelium after injury is driven mainly by plasticity of crypt stem cells that can rapidly divide to replace all the lost cells. Stem cell

  5. Plasticity of intestinal epithelial cells in regeneration and cancer

    NARCIS (Netherlands)

    Tetteh, Paul W.

    2015-01-01

    Cellular plasticity refers to the ability of a cell to change its fate or identity in response to external or intrinsic factors. Regeneration of the intestinal epithelium after injury is driven mainly by plasticity of crypt stem cells that can rapidly divide to replace all the lost cells. Stem cell

  6. Know your neighbor: Microbiota and host epithelial cells interact locally to control intestinal function and physiology.

    Science.gov (United States)

    Sommer, Felix; Bäckhed, Fredrik

    2016-05-01

    Interactions between the host and its associated microbiota differ spatially and the local cross talk determines organ function and physiology. Animals and their organs are not uniform but contain several functional and cellular compartments and gradients. In the intestinal tract, different parts of the gut carry out different functions, tissue structure varies accordingly, epithelial cells are differentially distributed and gradients exist for several physicochemical parameters such as nutrients, pH, or oxygen. Consequently, the microbiota composition also differs along the length of the gut, but also between lumen and mucosa of the same intestinal segment, and even along the crypt-villus axis in the epithelium. Thus, host-microbiota interactions are highly site-specific and the local cross talk determines intestinal function and physiology. Here we review recent advances in our understanding of site-specific host-microbiota interactions and discuss their functional relevance for host physiology.

  7. Immunopathology of giardiasis: the role of lymphocytes in intestinal epithelial injury and malfunction

    Directory of Open Access Journals (Sweden)

    AG Buret

    2005-03-01

    Full Text Available T lymphocyte-mediated pathogenesis is common to a variety of enteropathies, including giardiasis, cryptosporidiosis, bacterial enteritis, celiac's disease, food anaphylaxis, and Crohn's disease. In giardiasis as well as in these other disorders, a diffuse loss of microvillous brush border, combined or not with villus atrophy, is responsible for disaccharidase insufficiencies and malabsorption of electrolytes, nutrients, and water, which ultimately cause diarrheal symptoms. Other mucosal changes may include crypt hyperplasia and increased infiltration of intra-epithelial lymphocytes. Recent studies using models of giardiasis have shed new light on the immune regulation of these abnormalities. Indeed, experiments using an athymic mouse model of infection have found that these epithelial injuries were T cell-dependent. Findings from further research indicate that that the loss of brush border surface area, reduced disaccharidase activities, and increase crypt-villus ratios are mediated by CD8+ T cells, whereas both CD8+ and CD4+ small mesenteric lymph node T cells regulate the influx of intra-epithelial lymphocytes. Future investigations need to characterize the CD8+ T cell signaling cascades that ultimately lead to epithelial injury and malfunction in giardiasis and other malabsorptive disorders of the intestine.

  8. Role of Krüppel-like factor 5 in the maintenance of the stem cell niche in the intestinal crypt.

    Science.gov (United States)

    Kuruvilla, Jes G; Ghaleb, Amr M; Bialkowska, Agnieszka B; Nandan, Mandayam O; Yang, Vincent W

    The intestinal epithelium is a tissue that undergoes continuous self-renewal initiated at the bottom of the crypts, which harbor the intestinal stem cell (ISC) pool. The ISC pool is sub-divided into crypt base columnar (CBC) cells at the crypt bottom and label retention cells (LRC) at position +4 from the crypt bottom. CBC cells are marked by Leucine-rich repeat-containing G-protein coupled receptor (Lgr5) while LRC cells are identified by several markers including Bmi1, mTert, Hopx, Lrig1, and Sox9. Krüppel-like factors (KLFs) belong to a family of transcription factors that exert important physiological function in various tissues. In the intestine, KLF4 is predominantly expressed in the terminally differentiated, non-proliferating cells lining the villus. Its deletion in the adult mouse intestine results in perturbed homeostasis. In contrast, KLF5 is expressed in actively proliferating cells of the intestinal crypt, including CBC cells and transit amplifying (TA) cells. We recently investigated the effect of Klf5 deletion specifically from the Lgr5-expressing CBC cells in adult mouse intestine using an inducible Cre recombinase system. Shortly (3-5 days) after Cre induction, proliferation of both CBC and TA cells ceased, which was accompanied by an increase in apoptosis in the crypt. Beginning at two weeks following Cre induction, both Klf5 expression and proliferation re-appeared but without the re-emergence of Lgr5-positive CBC cells, which were eventually depleted by four months following induction. These findings indicate that KLF5 plays an important role in regulating proliferation and survival of CBC stem cells in the intestine.

  9. Microecology, intestinal epithelial barrier and necrotizing enterocolitis.

    Science.gov (United States)

    Sharma, Renu; Tepas, Joseph J

    2010-01-01

    Soon after birth, the neonatal intestine is confronted with a massive antigenic challenge of microbial colonization. Microbial signals are required for maturation of several physiological, anatomical, and biochemical functions of intestinal epithelial barrier (IEB) after birth. Commensal bacteria regulate intestinal innate and adaptive immunity and provide stimuli for ongoing repair and restitution of IEB. Colonization by pathogenic bacteria and/or dysmature response to microbial stimuli can result in flagrant inflammatory response as seen in necrotizing enterocolitis (NEC). Characterized by inflammation and hemorrhagic-ischemic necrosis, NEC is a devastating complication of prematurity. Although there is evidence that both prematurity and presence of bacteria, are proven contributing factors to the pathogenesis of NEC, the molecular mechanisms involved in IEB dysfunction associated with NEC have begun to emerge only recently. The metagenomic advances in the field of intestinal microecology are providing insight into the factors that are required for establishment of commensal bacteria that appear to provide protection against intestinal inflammation and NEC. Perturbations in achieving colonization by commensal bacteria such as premature birth or hospitalization in intensive care nursery can result in dysfunction of IEB and NEC. In this article, microbial modulation of functions of IEB and its relationship with barrier dysfunction and NEC are described.

  10. Chronic low vitamin intake potentiates cisplatin-induced intestinal epithelial cell apoptosis in WNIN rats

    Institute of Scientific and Technical Information of China (English)

    Bodiga Vijayalakshmi; Boindala Sesikeran; Putcha Udaykumar; Subramaniam Kalyanasundaram; Manchala Raghunath

    2006-01-01

    AIM: To investigate if cisplatin alters vitamin status and if VR modulates cisplatin induced intestinal apoptosis and oxidative stress in Wistar/NIN (WNIN) male rats.METHODS: Weanling, WNIN male rats (n = 12 per group) received adlibitum for 17 wk: control diet (20%protein) or the same with 50% vitamin restriction. They were then sub-divided into two groups of six rats each and administered cisplatin (2.61 mg/kg bodyweight)once a week for three wk or PBS (vehicle control).Intestinal epithelial cell (IEC) apoptosis was monitored by morphometry, Annexin-V binding, M30 cytodeath assay and DNA fragmentation. Structural and functional integrity of the villus were assessed by villus height /crypt depth ratio and activities of alkaline phosphatase,lys, ala-dipeptidyl amino-peptidase, respectively. To assess the probable mechanism(s) of altered apoptosis,oxidative stress parameters, caspase-3 activity, and expression of Bcl-2 and Bax were determined.RESULTS: Cisplatin per se decreased plasma vitamin levels and they were the lowest in VR animals treated with cisplatin. As expected VR increased only villus apoptosis, whereas cisplatin increased stem cell apoptosis in the crypt. However, cisplatin treatment of VR rats increased apoptosis both in villus and crypt regions and was associated with higher levels of TBARS,protein carbonyls and caspase-3 activity, but lower GSH concentrations. VR induced decrease in Bcl-2 expression was further lowered by cisplatin. Bax expression,unaffected by VR was increased on cisplatin treatment.Mucosal functional integrity was severely compromised in cisplatin treated VR-rats.CONCLUSION: Low intake of vitamins increases the sensitivity of rats to cisplatin and promotes intestinal epithelial cell apoptosis.

  11. Toxicity of food-relevant nanoparticles in intestinal epithelial models

    Science.gov (United States)

    McCracken, Christie

    Nanoparticles are increasingly being incorporated into common consumer products, including in foods and food packaging, for their unique properties at the nanoscale. Food-grade silica and titania are used as anti-caking and whitening agents, respectively, and these particle size distributions are composed of approximately one-third nanoparticles. Zinc oxide and silver nanoparticles can be used for their antimicrobial properties. However, little is known about the interactions of nanoparticles in the body upon ingestion. This study was performed to investigate the role of nanoparticle characteristics including surface chemistry, dissolution, and material type on toxicity to the intestinal epithelium. Only mild acute toxicity of zinc oxide nanoparticles was observed after 24-hour treatment of intestinal epithelial C2BBe1 cells based on the results of toxicity assays measuring necrosis, apoptosis, membrane damage, and mitochondrial activity. Silica and titanium dioxide nanoparticles were not observed to be toxic although all nanoparticles were internalized by cells. In vitro digestion of nanoparticles in solutions representing the stomach and intestines prior to treatment of cells did not alter nanoparticle toxicity. Long-term repeated treatment of cells weekly for 24 hours with nanoparticles did not change nanoparticle cytotoxicity or the growth rate of the treated cell populations. Thus, silica, titanium dioxide, and zinc oxide nanoparticles were found to induce little toxicity in intestinal epithelial cells. Fluorescent silica nanoparticles were synthesized as a model for silica used in foods that could be tracked in vitro and in vivo. To maintain an exterior of pure silica, a silica shell was hydrolyzed around a core particle of quantum dots or a fluorescent dye electrostatically associated with a commercial silica particle. The quantum dots used were optimized from a previously reported microwave quantum dot synthesis to a quantum yield of 40%. Characterization

  12. Protein tyrosine phosphatase σ targets apical junction complex proteins in the intestine and regulates epithelial permeability.

    Science.gov (United States)

    Murchie, Ryan; Guo, Cong-Hui; Persaud, Avinash; Muise, Aleixo; Rotin, Daniela

    2014-01-14

    Protein tyrosine phosphatase (PTP)σ (PTPRS) was shown previously to be associated with susceptibility to inflammatory bowel disease (IBD). PTPσ(-/-) mice exhibit an IBD-like phenotype in the intestine and show increased susceptibility to acute models of murine colitis. However, the function of PTPσ in the intestine is uncharacterized. Here, we show an intestinal epithelial barrier defect in the PTPσ(-/-) mouse, demonstrated by a decrease in transepithelial resistance and a leaky intestinal epithelium that was determined by in vivo tracer analysis. Increased tyrosine phosphorylation was observed at the plasma membrane of epithelial cells lining the crypts of the small bowel and colon of the PTPσ(-/-) mouse, suggesting the presence of PTPσ substrates in these regions. Using mass spectrometry, we identified several putative PTPσ intestinal substrates that were hyper-tyrosine-phosphorylated in the PTPσ(-/-) mice relative to wild type. Among these were proteins that form or regulate the apical junction complex, including ezrin. We show that ezrin binds to and is dephosphorylated by PTPσ in vitro, suggesting it is a direct PTPσ substrate, and identified ezrin-Y353/Y145 as important sites targeted by PTPσ. Moreover, subcellular localization of the ezrin phosphomimetic Y353E or Y145 mutants were disrupted in colonic Caco-2 cells, similar to ezrin mislocalization in the colon of PTPσ(-/-) mice following induction of colitis. Our results suggest that PTPσ is a positive regulator of intestinal epithelial barrier, which mediates its effects by modulating epithelial cell adhesion through targeting of apical junction complex-associated proteins (including ezrin), a process impaired in IBD.

  13. Influencing factors of rat small intestinal epithelial cell cultivation and effects of radiation on cell proliferation

    Institute of Scientific and Technical Information of China (English)

    Xin Ze Ran; Yong Ping Su; Yong Jiang Wei; Guo Ping Ai; Tian Min Cheng; Yuan Lin

    2001-01-01

    @@ INTRODUCTIONCrypt epithelial cells in normal small intestineproliferate at a high speed. But they are verydifficult to culture in vitro and passage stably. A lotof studies have been done[1-16]. Some domestic labsisolated and cultured crypt cells from embryonalintestines and aseptic animal intestine, but failed.We introduced normal rat epithelial cell line-IEC-6from the USA and its living condition for stablepassage was successfully established after trials. Thecell line was testified to be the small intestinalepithelial cell by electron microscopy,immunihistochemistry and enzymatic histoch-emistry. It has been applied to some relatedresearch work[17-21]. It was found that manyfactors were involved in the culture system. Ourpresent study focuses on the culture method and theinfluencing factors on IEC-6.

  14. Insights into regulatory molecules of intestinal epithelial cell turnover during experimental infection by Heterophyes heterophyes.

    Science.gov (United States)

    Ashour, Dalia S; Othman, Ahmad A; Radi, Dina A

    2014-08-01

    Heterophyiasis is an intestinal disease that remains endemic in many parts of the world, particularly the Nile Delta of Egypt and Southeast Asia, yet the populations at risk of infection expand throughout the world. The main histopathological feature of infection is villous atrophy, but the underlying factors are not well understood. Apoptosis of the villous epithelial cells was previously reported to be enhanced during intestinal parasitic infections; however, the role of Heterophyes heterophyes on enterocyte apoptosis was to be explored. Therefore, intestinal sections from mice experimentally infected with H. heterophyes were studied histopathologically and immunohistochemically for caspase-3 and NF-κB and compared to non-infected control mice. Atrophic villi covered by poorly differentiated epithelial cells were observed in the 2nd week post-infection. Also, we noted marked hyperplasia of the intestinal crypts with abundant inflammatory cellular infiltrate in the lamina propria, as well as apoptosis of cells lining the intestinal villi. Both caspase-3 and NF-κB showed positive staining in the intestinal epithelial cells with varying grades of intensity over the length of infection. Caspase-3 expression rose at the 2nd week p.i. then decreased over time, whereas NF-κB expression showed progressive increase throughout the weeks of infection. In conclusion, caspase-3 activation may be an important factor in the apoptotic pathway in early heterophyiasis, and, on the other hand, NF-κB seems to play a role in protecting the intestinal cells from excessive apoptosis. These observations may help open new avenues for tissue protective therapies that avoid or control the deleterious processes of apoptosis in various inflammatory conditions. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Preterm infant gut microbiota affects intestinal epithelial development in a humanized microbiome gnotobiotic mouse model.

    Science.gov (United States)

    Yu, Yueyue; Lu, Lei; Sun, Jun; Petrof, Elaine O; Claud, Erika C

    2016-09-01

    Development of the infant small intestine is influenced by bacterial colonization. To promote establishment of optimal microbial communities in preterm infants, knowledge of the beneficial functions of the early gut microbiota on intestinal development is needed. The purpose of this study was to investigate the impact of early preterm infant microbiota on host gut development using a gnotobiotic mouse model. Histological assessment of intestinal development was performed. The differentiation of four epithelial cell lineages (enterocytes, goblet cells, Paneth cells, enteroendocrine cells) and tight junction (TJ) formation was examined. Using weight gain as a surrogate marker for health, we found that early microbiota from a preterm infant with normal weight gain (MPI-H) induced increased villus height and crypt depth, increased cell proliferation, increased numbers of goblet cells and Paneth cells, and enhanced TJs compared with the changes induced by early microbiota from a poor weight gain preterm infant (MPI-L). Laser capture microdissection (LCM) plus qRT-PCR further revealed, in MPI-H mice, a higher expression of stem cell marker Lgr5 and Paneth cell markers Lyz1 and Cryptdin5 in crypt populations, along with higher expression of the goblet cell and mature enterocyte marker Muc3 in villus populations. In contrast, MPI-L microbiota failed to induce the aforementioned changes and presented intestinal characteristics comparable to a germ-free host. Our data demonstrate that microbial communities have differential effects on intestinal development. Future studies to identify pioneer settlers in neonatal microbial communities necessary to induce maturation may provide new insights for preterm infant microbial ecosystem therapeutics. Copyright © 2016 the American Physiological Society.

  16. The effects of herbs on the radiation-induced apoptosis in intestinal crypt cells

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Ho; An, Mi Ra; Nah, Seung Yeol; Lee, Jong Hwan; Kim, Jae Ha; Shin, Dong Ho [Chonnam National Univ., Gwangju (Korea, Republic of); Jo, Sung Kee [KAERI, Daejeon (Korea, Republic of); Jang, Jong Sik [Sangju National Univ., Sangju (Korea, Republic of)

    2001-03-15

    This study was performed to determine the effect of several herbs on radiation-induced apoptosis in jejunal crypt cells. Longyanrou(Euphoris logana), Suanzaoren(Zizyphus vulgaris), Yuanzhi(Polygala tenuifolia), Rensan(Panax ginseng), Fuling(Poria cocos), Muxiang(Saussurea lappa), Chuanxiong(Cnidium offcinale), Baishaoyao(Paeonia lactifolia), Shengma(Cimicifuga heracleifolia), Chaihu(Bupleurum falcatum) and Dongchongxiacao(Paecilomyces japonica) reduced the frequency of radiation-induced apoptosis(p<0.05). Although the mechanisms of this effect remain to be elucidated, these results indicated that Longyanrou, Suanzaoren, Yuanzhi, Rensan, Fuling, Muxiang, Chuanxiong, Baishaoyao, Shengma, Chaihu and Dongchongxiacao might be useful inhibitors of apoptosis, especially since these are relative nontoxic natural products.

  17. Intestinal epithelial tuft cells initiate type 2 mucosal immunity to helminth parasites.

    Science.gov (United States)

    Gerbe, François; Sidot, Emmanuelle; Smyth, Danielle J; Ohmoto, Makoto; Matsumoto, Ichiro; Dardalhon, Valérie; Cesses, Pierre; Garnier, Laure; Pouzolles, Marie; Brulin, Bénédicte; Bruschi, Marco; Harcus, Yvonne; Zimmermann, Valérie S; Taylor, Naomi; Maizels, Rick M; Jay, Philippe

    2016-01-14

    Helminth parasitic infections are a major global health and social burden. The host defence against helminths such as Nippostrongylus brasiliensis is orchestrated by type 2 cell-mediated immunity. Induction of type 2 cytokines, including interleukins (IL) IL-4 and IL-13, induce goblet cell hyperplasia with mucus production, ultimately resulting in worm expulsion. However, the mechanisms underlying the initiation of type 2 responses remain incompletely understood. Here we show that tuft cells, a rare epithelial cell type in the steady-state intestinal epithelium, are responsible for initiating type 2 responses to parasites by a cytokine-mediated cellular relay. Tuft cells have a Th2-related gene expression signature and we demonstrate that they undergo a rapid and extensive IL-4Rα-dependent amplification following infection with helminth parasites, owing to direct differentiation of epithelial crypt progenitor cells. We find that the Pou2f3 gene is essential for tuft cell specification. Pou2f3(-/-) mice lack intestinal tuft cells and have defective mucosal type 2 responses to helminth infection; goblet cell hyperplasia is abrogated and worm expulsion is compromised. Notably, IL-4Rα signalling is sufficient to induce expansion of the tuft cell lineage, and ectopic stimulation of this signalling cascade obviates the need for tuft cells in the epithelial cell remodelling of the intestine. Moreover, tuft cells secrete IL-25, thereby regulating type 2 immune responses. Our data reveal a novel function of intestinal epithelial tuft cells and demonstrate a cellular relay required for initiating mucosal type 2 immunity to helminth infection.

  18. Proliferation and mRNA expression of absorptive villous cell markers and mineral transporters in prolactin-exposed IEC-6 intestinal crypt cells.

    Science.gov (United States)

    Teerapornpuntakit, Jarinthorn; Wongdee, Kannikar; Thongbunchoo, Jirawan; Krishnamra, Nateetip; Charoenphandhu, Narattaphol

    2012-06-01

    During pregnancy and lactation, prolactin (PRL) enhances intestinal absorption of calcium and other minerals for fetal development and milk production. Although an enhanced absorptive efficiency is believed to mainly result from the upregulation of mineral transporters in the absorptive villous cells, some other possibilities, such as PRL-enhanced crypt cell proliferation and differentiation to increase the absorptive area, have never been ruled out. Here, we investigated cell proliferation and mRNA expression of mineral absorption-related genes in the PRL-exposed IEC-6 crypt cells. As expected, the cell proliferation was not altered by PRL. Inasmuch as the mRNA expressions of villous cell markers, including dipeptidylpeptidase-4, lactase and glucose transporter-5, were not increased, PRL was not likely to enhance crypt cell differentiation into the absorptive villous cells. In contrast to the previous findings in villous cells, PRL was found to downregulate the expression of calbindin-D(9k), claudin-3 and occludin in IEC-6 crypt cells, while having no effect on transient receptor potential vanilloid family channels-5/6, plasma membrane Ca(2+)-ATPase (PMCA)-1b and Na(+)/Ca(2+) exchanger-1 expression. In conclusion, IEC-6 crypt cells did not respond to PRL by increasing proliferation or differentiation into villous cells. The present results thus supported the previous hypothesis that PRL enhanced mineral absorption predominantly by increasing transporter expression and activity in the absorptive villous cells. Copyright © 2012 John Wiley & Sons, Ltd.

  19. Intestinal epithelial organoids fuse to form self-organizing tubes in floating collagen gels.

    Science.gov (United States)

    Sachs, Norman; Tsukamoto, Yoshiyuki; Kujala, Pekka; Peters, Peter J; Clevers, Hans

    2017-03-15

    Multiple recent examples highlight how stem cells can self-organize in vitro to establish organoids that closely resemble their in vivo counterparts. Single Lgr5(+) mouse intestinal stem cells can be cultured under defined conditions forming ever-expanding epithelial organoids that retain cell polarization, cell type diversity and anatomical organization of the in vivo epithelium. Although exhibiting a remarkable level of self-organization, the so called 'mini-guts' have a closed cystic structure of microscopic size. Here, we describe a simple protocol to generate macroscopic intestinal tubes from small cystic organoids. Embedding proliferating organoids within a contracting floating collagen gel allows them to align and fuse to generate macroscopic hollow structures ('tubes') that are lined with a simple epithelium containing all major cell types (including functional stem cells) of the small intestine. Cells lining the central contiguous lumen closely resemble the epithelial cells on luminal villi in vivo, whereas buds that protrude from the main tube into the surrounding matrix closely resemble crypts. Thus, the remarkable self-organizing properties of Lgr5(+) stem cells extend beyond the level of the microscopic cystic organoid to the next, macroscopic, level of tube formation. © 2017. Published by The Company of Biologists Ltd.

  20. Salmonella infection upregulates the leaky protein claudin-2 in intestinal epithelial cells.

    Directory of Open Access Journals (Sweden)

    Yong-guo Zhang

    Full Text Available BACKGROUND: Tight junctions seal the space between adjacent epithelial cells. Mounting evidence suggests that tight junction proteins play a key role in the pathogenesis of human disease. Claudin is a member of the tight junction protein family, which has 24 members in humans. To regulate cellular function, claudins interact structurally and functionally with membrane and scaffolding proteins via their cytoplasmic domain. In particular, claudin-2 is known to be a leaky protein that contributes to inflammatory bowel disease and colon cancer. However, the involvement of claudin-2 in bacterial infection in the intestine remains unknown. METHODS/PRINCIPAL FINDINGS: We hypothesized that Salmonella elevates the leaky protein claudin-2 for its own benefit to facilitate bacterial invasion in the colon. Using a Salmonella-colitis mouse model and cultured colonic epithelial cells, we found that pathogenic Salmonella colonization significantly increases the levels of claudin-2 protein and mRNA in the intestine, but not that of claudin-3 or claudin-7 in the colon, in a time-dependent manner. Immunostaining studies showed that the claudin-2 expression along the crypt-villous axis postinfection. In vitro, Salmonella stimulated claudin-2 expression in the human intestinal epithelial cell lines SKCO15 and HT29C19A. Further analysis by siRNA knockdown revealed that claudin-2 is associated with the Salmonella-induced elevation of cell permeability. Epithelial cells with claudin-2 knockdown had significantly less internalized Salmonella than control cells with normal claudin-2 expression. Inhibitor assays demonstrated that this regulation is mediated through activation of the EGFR pathway and the downstream protein JNK. CONCLUSION/SIGNIFICANCE: We have shown that Salmonella targets the tight junction protein claudin-2 to facilitate bacterial invasion. We speculate that this disruption of barrier function contributes to a new mechanism by which bacteria interact

  1. Activation of epithelial STAT3 regulates intestinal homeostasis.

    Science.gov (United States)

    Neufert, Clemens; Pickert, Geethanjali; Zheng, Yan; Wittkopf, Nadine; Warntjen, Moritz; Nikolaev, Alexei; Ouyang, Wenjun; Neurath, Markus F; Becker, Christoph

    2010-02-15

    The intestinal epithelium that lines the mucosal surface along the GI-tract is a key player for the intestinal homeostasis of the healthy individual. In case of a mucosal damage or a barrier defect as seen in patients with inflammatory bowel disease, the balance is disturbed, and translocation of intestinal microbes to the submucosa is facilitated. We recently demonstrated a pivotal role of STAT3 activation in intestinal epithelial cells (IEC) for the restoration of the balance at the mucosal surface of the gut in an experimental colitis model. STAT3 was rapidly induced in intestinal epithelial cells upon challenge of mice in both experimental colitis and intestinal wound healing models. STAT3 activation was found to be dispensable in the steady-state conditions but was important for efficient regeneration of the epithelium in response to injury. Here, we extend our previous findings by showing epithelial STAT3 activation in human patients suffering from IBD and provide additional insights how the activation of epithelial STAT3 by IL-22 regulates intestinal homeostasis and mucosal wound healing. We also demonstrate that antibody-mediated neutralization of IL-22 has little impact on the development of experimental colitis in mice, but significantly delays recovery from colitis. Thus, our data suggest that targeting the STAT3 signaling pathway in IEC is a promising therapeutic approach in situations when the intestinal homeostasis is disturbed, e.g., as seen in Crohn's disease or Ulcerative colitis.

  2. Orally administered lactoperoxidase increases expression of the FK506 binding protein 5 gene in epithelial cells of the small intestine of mice: a DNA microarray study.

    Science.gov (United States)

    Wakabayashi, Hiroyuki; Miyauchi, Hirofumi; Shin, Kouichirou; Yamauchi, Koji; Matsumoto, Ichiro; Abe, Keiko; Takase, Mitsunori

    2007-09-01

    Lactoperoxidase (LPO) is a component of milk and other external secretions. To study the influence of ingested LPO on the digestive tract, we performed DNA microarray analysis of the small intestine of mice administered LPO. LPO administration upregulated 78 genes, including genes involved in metabolism, immunity, apoptosis, and the cell cycle, and downregulated nine genes, including immunity-related genes. The most upregulated gene was FK506 binding protein 5 (FKBP5), a glucocorticoid regulating immunophilin. The upregulation of this gene was confirmed by quantitative RT-PCR in other samples. In situ hybridization revealed that expression of the FKBP5 gene in the crypt epithelial cells of the small intestine was enhanced by LPO. These results suggest that ingested LPO modulates gene expression in the small intestine and especially increases FKBP5 gene expression in the epithelial cells of the intestine.

  3. Interferon-gamma regulation of intestinal epithelial permeability.

    Science.gov (United States)

    Beaurepaire, Cécile; Smyth, David; McKay, Derek M

    2009-03-01

    The maintenance and regulation of the barrier function of the epithelial lining of the intestine are important homeostatic events, serving to allow selective absorption from the gut lumen while simultaneously limiting the access of bacteria into the mucosa. Interferon-gamma is a pleiotrophic cytokine produced predominantly by natural kill cells and CD4+ T cells that under normal circumstances, and particularly during infection or inflammation, will be a component of the intestinal milieu. Use of colon-derived epithelial cell lines and, to a less extent, murine in vivo analyses, have revealed that interferon-gamma (IFN-gamma) can increase epithelial permeability as gauged by markers of paracellular permeability and bacterial transcytosis, with at least a portion of the bacteria using the transcellular permeation pathway. In this review, we describe the main characteristics of epithelial permeability and then focus on the ability of IFN-gamma to increase epithelial permeability, and the mechanism(s) thereof.

  4. Lawsonia intracellularis exploits β-catenin/Wnt and Notch signalling pathways during infection of intestinal crypt to alter cell homeostasis and promote cell proliferation

    Science.gov (United States)

    Huan, Yang W.; Bengtsson, Rebecca J.; MacIntyre, Neil; Guthrie, Jack; Finlayson, Heather; Smith, Sionagh H.; Archibald, Alan L.; Ait-Ali, Tahar

    2017-01-01

    Lawsonia intracellularis is an obligate intracellular bacterial pathogen that causes proliferative enteropathy (PE) in pigs. L. intracellularis infection causes extensive intestinal crypt cell proliferation and inhibits secretory and absorptive cell differentiation. However, the affected host upstream cellular pathways leading to PE are still unknown. β-catenin/Wnt signalling is essential in maintaining intestinal stem cell (ISC) proliferation and self-renewal capacity, while Notch signalling governs differentiation of secretory and absorptive lineage specification. Therefore, in this report we used immunofluorescence (IF) and quantitative reverse transcriptase PCR (RTqPCR) to examine β-catenin/Wnt and Notch-1 signalling levels in uninfected and L. intracellularis infected pig ileums at 3, 7, 14, 21 and 28 days post challenge (dpc). We found that while the significant increase in Ki67+ nuclei in crypts at the peak of L. intracellularis infection suggested enhanced cell proliferation, the expression of c-MYC and ASCL2, promoters of cell growth and ISC proliferation respectively, was down-regulated. Peak infection also coincided with enhanced cytosolic and membrane-associated β-catenin staining and induction of AXIN2 and SOX9 transcripts, both encoding negative regulators of β-catenin/Wnt signalling and suggesting a potential alteration to β-catenin/Wnt signalling levels, with differential regulation of the expression of its target genes. We found that induction of HES1 and OLFM4 and the down-regulation of ATOH1 transcript levels was consistent with the increased Notch-1 signalling in crypts at the peak of infection. Interestingly, the significant down-regulation of ATOH1 transcript levels coincided with the depletion of MUC2 expression at 14 dpc, consistent with the role of ATOH1 in promoting goblet cell maturation. The lack of significant change to LGR5 transcript levels at the peak of infection suggested that the crypt hyperplasia was not due to the expansion

  5. Epithelial NEMO links innate immunity to chronic intestinal inflammation.

    Science.gov (United States)

    Nenci, Arianna; Becker, Christoph; Wullaert, Andy; Gareus, Ralph; van Loo, Geert; Danese, Silvio; Huth, Marion; Nikolaev, Alexei; Neufert, Clemens; Madison, Blair; Gumucio, Deborah; Neurath, Markus F; Pasparakis, Manolis

    2007-03-29

    Deregulation of intestinal immune responses seems to have a principal function in the pathogenesis of inflammatory bowel disease. The gut epithelium is critically involved in the maintenance of intestinal immune homeostasis-acting as a physical barrier separating luminal bacteria and immune cells, and also expressing antimicrobial peptides. However, the molecular mechanisms that control this function of gut epithelial cells are poorly understood. Here we show that the transcription factor NF-kappaB, a master regulator of pro-inflammatory responses, functions in gut epithelial cells to control epithelial integrity and the interaction between the mucosal immune system and gut microflora. Intestinal epithelial-cell-specific inhibition of NF-kappaB through conditional ablation of NEMO (also called IkappaB kinase-gamma (IKKgamma)) or both IKK1 (IKKalpha) and IKK2 (IKKbeta)-IKK subunits essential for NF-kappaB activation-spontaneously caused severe chronic intestinal inflammation in mice. NF-kappaB deficiency led to apoptosis of colonic epithelial cells, impaired expression of antimicrobial peptides and translocation of bacteria into the mucosa. Concurrently, this epithelial defect triggered a chronic inflammatory response in the colon, initially dominated by innate immune cells but later also involving T lymphocytes. Deficiency of the gene encoding the adaptor protein MyD88 prevented the development of intestinal inflammation, demonstrating that Toll-like receptor activation by intestinal bacteria is essential for disease pathogenesis in this mouse model. Furthermore, NEMO deficiency sensitized epithelial cells to tumour-necrosis factor (TNF)-induced apoptosis, whereas TNF receptor-1 inactivation inhibited intestinal inflammation, demonstrating that TNF receptor-1 signalling is crucial for disease induction. These findings demonstrate that a primary NF-kappaB signalling defect in intestinal epithelial cells disrupts immune homeostasis in the gastrointestinal tract

  6. Cell organisation in the colonic crypt: a theoretical comparison of the pedigree and niche concepts.

    Directory of Open Access Journals (Sweden)

    Richard C van der Wath

    Full Text Available The intestinal mucosa is a monolayer of rapidly self-renewing epithelial cells which is not only responsible for absorption of water and nutrients into the bloodstream but also acts as a protective barrier against harmful microbes entering the body. New functional epithelial cells are produced from stem cells, and their proliferating progeny. These stem cells are found within millions of crypts (tubular pits spaced along the intestinal tract. The entire intestinal epithelium is replaced every 2-3 days in mice (3-5 days in humans and hence cell production, differentiation, migration and turnover need to be tightly regulated. Malfunctions in this regulation are strongly linked to inflammatory bowel diseases and to the formation of adenomas and ultimately cancerous tumours. Despite a great deal of biological experimentation and observation, precisely how colonic crypts are regulated to produce mature colonocytes remains unclear. To assist in understanding how cell organisation in crypts is achieved, two very different conceptual models of cell behaviour are developed here, referred to as the 'pedigree' and the 'niche' models. The pedigree model proposes that crypt cells are largely preprogrammed and receive minimal prompting from the environment as they move through a routine of cell differentiation and proliferation to become mature colonocytes. The niche model proposes that crypt cells are primarily influenced by the local microenvironments along the crypt, and that predetermined cell behaviour plays a negligible role in their development. In this paper we present a computational model of colonic crypts in the mouse, which enables a comparison of the quality and controllability of mature coloncyte production by crypts operating under these two contrasting conceptual models of crypt regulation.

  7. Cell Organisation in the Colonic Crypt: A Theoretical Comparison of the Pedigree and Niche Concepts

    Science.gov (United States)

    van der Wath, Richard C.; Gardiner, Bruce S.; Burgess, Antony W.; Smith, David W.

    2013-01-01

    The intestinal mucosa is a monolayer of rapidly self-renewing epithelial cells which is not only responsible for absorption of water and nutrients into the bloodstream but also acts as a protective barrier against harmful microbes entering the body. New functional epithelial cells are produced from stem cells, and their proliferating progeny. These stem cells are found within millions of crypts (tubular pits) spaced along the intestinal tract. The entire intestinal epithelium is replaced every 2–3 days in mice (3–5 days in humans) and hence cell production, differentiation, migration and turnover need to be tightly regulated. Malfunctions in this regulation are strongly linked to inflammatory bowel diseases and to the formation of adenomas and ultimately cancerous tumours. Despite a great deal of biological experimentation and observation, precisely how colonic crypts are regulated to produce mature colonocytes remains unclear. To assist in understanding how cell organisation in crypts is achieved, two very different conceptual models of cell behaviour are developed here, referred to as the ‘pedigree’ and the ‘niche’ models. The pedigree model proposes that crypt cells are largely preprogrammed and receive minimal prompting from the environment as they move through a routine of cell differentiation and proliferation to become mature colonocytes. The niche model proposes that crypt cells are primarily influenced by the local microenvironments along the crypt, and that predetermined cell behaviour plays a negligible role in their development. In this paper we present a computational model of colonic crypts in the mouse, which enables a comparison of the quality and controllability of mature coloncyte production by crypts operating under these two contrasting conceptual models of crypt regulation. PMID:24069177

  8. Migration of epithelial cells in the small intestine of mice perorally infected with coxsackievirus B5.

    Science.gov (United States)

    Shadoff, N; Loria, R M; Kibrick, S; Broitman, S A

    1979-03-01

    The rate of cell migration in the small intestine during enteric viral infections has not been assessed previously. CD-1 mice (33 days old) were infected perorally with 1.0 X 10(8) plague-forming units of coxsackievirus B5 and 12 hr later were injected intraperitoneally with 2 micron Ci of [3H]thymidine/g of body weight. After 2, 12, 24, 48, 60, and 72 hr, mice were killed, and the small intestine was removed. Specimens obtained at each interval were examined by radioautography; similar specimens were titrated for virus by plaque assay in HeLa cells. In mice perorally infected with coxsackievirus B5, epithelial cells migrated from crypt to villus tip in 60 hr, as compared with 48 hr in uninfected control mice and 24 hr previously reported for mice perorally infected with enteric bacteria (e.g., Salmonella typhimurium). Virus was recovered from intestinal tissue, but no inflammatory response in the limina propria was apparent. These observations are consistent with previous report that substrate absorption rates may be altered during viral and bacterial enteric infection.

  9. Serum and fecal canine α1-proteinase inhibitor concentrations reflect the severity of intestinal crypt abscesses and/or lacteal dilation in dogs.

    Science.gov (United States)

    Heilmann, Romy M; Parnell, Nolie K; Grützner, Niels; Mansell, Joanne; Berghoff, Nora; Schellenberg, Stefan; Reusch, Claudia E; Suchodolski, Jan S; Steiner, Jörg M

    2016-01-01

    Gastrointestinal (GI) protein loss, due to lymphangiectasia or chronic inflammation, can be challenging to diagnose. This study evaluated the diagnostic accuracy of serum and fecal canine α1-proteinase inhibitor (cα1PI) concentrations to detect crypt abscesses and/or lacteal dilation in dogs. Serum and fecal cα1PI concentrations were measured in 120 dogs undergoing GI tissue biopsies, and were compared between dogs with and without crypt abscesses/lacteal dilation. Sensitivity and specificity were calculated for dichotomous outcomes. Serial serum cα1PI concentrations were also evaluated in 12 healthy corticosteroid-treated dogs. Serum cα1PI and albumin concentrations were significantly lower in dogs with crypt abscesses and/or lacteal dilation than in those without (both P <0.001), and more severe lesions were associated with lower serum cα1PI concentrations, higher 3 days-mean fecal cα1PI concentrations, and lower serum/fecal cα1PI ratios. Serum and fecal cα1PI, and their ratios, distinguished dogs with moderate or severe GI crypt abscesses/lacteal dilation from dogs with only mild or none such lesions with moderate sensitivity (56-92%) and specificity (67-81%). Serum cα1PI concentrations increased during corticosteroid administration. We conclude that serum and fecal α1PI concentrations reflect the severity of intestinal crypt abscesses/lacteal dilation in dogs. Due to its specificity for the GI tract, measurement of fecal cα1PI appears to be superior to serum cα1PI for diagnosing GI protein loss in dogs. In addition, the serum/fecal cα1PI ratio has an improved accuracy in hypoalbuminemic dogs, but serum cα1PI concentrations should be carefully interpreted in corticosteroid-treated dogs.

  10. A novel role of intestine epithelial GABAergic signaling in regulating intestinal fluid secretion.

    Science.gov (United States)

    Li, Yan; Xiang, Yun-Yan; Lu, Wei-Yang; Liu, Chuanyong; Li, Jingxin

    2012-08-15

    γ-Aminobutyric acid (GABA) is the primary inhibitory neurotransmitter in the central nervous system, and it is produced via the enzymatic activity of glutamic acid decarboxylase (GAD). GABA generates fast biological signaling through type A receptors (GABA(A)R), an anionic channel. Intriguingly, GABA is found in the jejunum epithelium of rats. The present study intended to determine whether a functional GABA signaling system exists in the intestinal epithelium and if so whether the GABA signaling regulates intestinal epithelial functions. RT-PCR, Western blot, and immunohistochemical assays of small intestinal tissues of various species were performed to determine the expression of GABA-signaling proteins in intestinal epithelial cells. Perforated patch-clamp recording was used to measure GABA-induced transmembrane current in the small intestine epithelial cell line IEC-18. The fluid weight-to-intestine length ratio was measured in mice that were treated with GABA(A)R agonist and antagonist. The effect of GABA(A)R antagonist on allergic diarrhea was examined using a mouse model. GABA, GAD, and GABA(A)R subunits were identified in small intestine epithelial cells of mice, rats, pigs, and humans. GABA(A)R agonist induced an inward current and depolarized IEC-18. Both GABA and the GABA(A)R agonist muscimol increased intestinal fluid secretion of rats. The increased intestinal secretion was largely decreased by the GABA(A)R antagonist picrotoxin or gabazine, but not by tetrodotoxin. The expression levels of GABA-signaling proteins were increased in the intestinal epithelium of mice that were sensitized and challenged with ovalbumin (OVA). The OVA-treated mice exhibited diarrhea, which was alleviated by oral administration of gabazine or picrotoxin. An endogenous autocrine GABAergic signaling exists in the mammalian intestinal epithelium, which upregulates intestinal fluid secretion. The intestinal GABAergic signaling becomes intensified in allergic diarrhea, and

  11. Intestinal alkaline phosphatase contributes to the reduction of severe intestinal epithelial damage.

    NARCIS (Netherlands)

    Bol-Schoenmakers, M.; Fiechter, D.; Raaben, W.; Hassing, I.; Bleumink, R.; Kruijswijk, D.; Maijoor, K.; Tersteeg-Zijderveld, M.; Brands, R.; Pieters, R.

    2010-01-01

    Inflammatory bowel disease is characterized by chronic inflammation of the intestine and is accompanied by damage of the epithelial lining and by undesired immune responses towards enteric bacteria. It has been demonstrated that intestinal alkaline phosphatase (iAP) protects against the induction of

  12. Instabilities of monolayered epithelia: shape and structure of villi and crypts

    CERN Document Server

    Hannezo, Edouard; Joanny, Jean-Francois; 10.1103/PhysRevLett.107.078104

    2012-01-01

    We study theoretically the shapes of a dividing epithelial monolayer of cells lying on top of an elastic stroma. The negative tension created by cell division provokes a buckling instability at a finite wave vector leading to the formation of periodic arrays of villi and crypts. The instability is similar to the buckling of a metallic plate under compression. We use the results to rationalize the various structures of the intestinal lining observed \\emph{in vivo}. Taking into account the coupling between cell division and local curvature, we obtain different patterns of villi and crypts, which could explain the different morphologies of the small intestine and the colon.

  13. Instabilities of Monolayered Epithelia: Shape and Structure of Villi and Crypts

    Science.gov (United States)

    Hannezo, E.; Prost, J.; Joanny, J.-F.

    2011-08-01

    We study theoretically the shapes of a dividing epithelial monolayer of cells lying on top of an elastic stroma. The negative tension created by cell division provokes a buckling instability at a finite wave vector leading to the formation of periodic arrays of villi and crypts. The instability is similar to the buckling of a metallic plate under compression. We use the results to rationalize the various structures of the intestinal lining observed in vivo. Taking into account the coupling between cell division and local curvature, we obtain different patterns of villi and crypts, which could explain the different morphologies of the small intestine and the colon.

  14. SIRT1 inhibits the mouse intestinal motility and epithelial proliferation

    Science.gov (United States)

    SIRT1 inhibits the mouse intestinal motility and epithelial proliferation. Sirtuin 1 (SIRT1), a NAD+-dependent histone deacetylase, is involved in a wide array of cellular processes, including glucose homeostasis, energy metabolism, proliferation and apoptosis, and immune response. However, it is un...

  15. Differential alterations in the small intestine epithelial cell turnover during acute and chronic infection with Echinostoma caproni (Trematoda).

    Science.gov (United States)

    Cortés, Alba; Muñoz-Antoli, Carla; Martín-Grau, Carla; Esteban, J Guillermo; Grencis, Richard K; Toledo, Rafael

    2015-06-18

    The intestinal epithelium plays a multifactorial role in mucosal defense. In this sense, augmented epithelial cell turnover appears as a potential effector mechanism for the rejection of intestinal-dwelling helminths. A BrdU pulse-chase experiment was conducted to investigate the infection-induced alterations on epithelial cell kinetics in hosts of high (mouse) and low (rat) compatibility with the intestinal trematode Echinostoma caproni. High levels of crypt-cell proliferation and tissue hyperplasia were observed in the ileum of infected mice, coinciding with the establishment of chronic infections. In contrast, the cell migration rate was about two times higher in the ileum of infected rats compared with controls, with no changes in tissue structure, indicating that an accelerated cell turnover is associated with worm expulsion. Our results indicate that E. caproni infection induces a rapid renewal of the intestinal epithelium in the low compatible host that may impair the establishment of proper, stable host-parasite interactions, facilitating worm clearance.

  16. Different effects of short- and long-chained fructans on large intestinal physiology and carcinogen-induced aberrant crypt foci in rats

    DEFF Research Database (Denmark)

    Poulsen, Morten; Molck, Anne-Marie; Jacobsen, Bodil Lund

    2002-01-01

    -type fructan on 1,2-dimethylhydrazine dihydrochloride-induced aberrant crypt foci (ACF) in the rat colon. In addition, the present study investigated the influence of chain length, dietary level (5% or 15%), and duration of feeding (5 or 10 wk) on the following intestinal parameters supposed to be involved......Inulin-type fructans, which are nondigestible carbohydrates, have been shown to modulate the number of induced preneoplastic lesions in the colon as well as the colonic microflora in laboratory animals. The present study was designed to investigate the effect of a short- and long-chained inulin...

  17. Regulatory effect of heat shock protein 70 in stress-induced rat intestinal epithelial barrier dysfunction

    Directory of Open Access Journals (Sweden)

    Stevie Struiksma

    2009-06-01

    Full Text Available Background: Psychological stress is one of the factors associated with many human diseases; the mechanisms need to be further understood. Methods: Rats were subjected to chronic water avoid stress. Intestinal epithelial heat shock protein (HSP 70 was evaluated. The intestinal epithelial permeability was examined with Ussing chamber technique. Results: HSP70 was detected in normal intestinal epithelial cells. Psychological stress decreased HSP70 in the intestinal epithelial cells that correlated with the stress-induced intestinal epithelial hyperpermeability. Pretreatment with HSP70 abrogated stress-induced intestinal barrier dysfunction. Conclusions: Chronic stress inhibits HSP70 activity in rat intestinal epithelial layer that is associated with intestinal epithelial barrier dysfunction, which can be prevented by pretreatment with HSP70 protein.

  18. Fish oil enhances recovery of intestinal microbiota and epithelial integrity in chronic rejection of intestinal transplant.

    Directory of Open Access Journals (Sweden)

    Qiurong Li

    Full Text Available BACKGROUND: The intestinal chronic rejection (CR is the major limitation to long-term survival of transplanted organs. This study aimed to investigate the interaction between intestinal microbiota and epithelial integrity in chronic rejection of intestinal transplantation, and to find out whether fish oil enhances recovery of intestinal microbiota and epithelial integrity. METHODS/PRINCIPAL FINDINGS: The luminal and mucosal microbiota composition of CR rats were characterized by DGGE analysis at 190 days after intestinal transplant. The specific bacterial species were determined by sequence analysis. Furthermore, changes in the localization of intestinal TJ proteins were examined by immunofluorescent staining. PCR-DGGE analysis revealed that gut microbiota in CR rats had a shift towards Escherichia coli, Bacteroides spp and Clostridium spp and a decrease in the abundance of Lactobacillales bacteria in the intestines. Fish oil supplementation could enhance the recovery of gut microbiota, showing a significant decrease of gut bacterial proportions of E. coli and Bacteroides spp and an increase of Lactobacillales spp. In addition, CR rats showed pronounced alteration of tight junction, depicted by marked changes in epithelial cell ultrastructure and redistribution of occuldin and claudins as well as disruption in TJ barrier function. Fish oil administration ameliorated disruption of epithelial integrity in CR, which was associated with an improvement of the mucosal structure leading to improved tight junctions. CONCLUSIONS/SIGNIFICANCE: Our study have presented novel evidence that fish oil is involved in the maintenance of epithelial TJ integrity and recovery of gut microbiota, which may have therapeutic potential against CR in intestinal transplantation.

  19. Up-regulation of intestinal epithelial cell derived IL-7 expression by keratinocyte growth factor through STAT1/IRF-1, IRF-2 pathway.

    Directory of Open Access Journals (Sweden)

    Yu-Jiao Cai

    Full Text Available BACKGROUND: Epithelial cells(EC-derived interleukin-7 (IL-7 plays a crucial role in control of development and homeostasis of neighboring intraepithelial lymphocytes (IEL, and keratinocyte growth factor (KGF exerts protective effects on intestinal epithelial cells and up-regulates EC-derived IL-7 expression through KGFR pathway. This study was to further investigate the molecular mechanism involved in the regulation of IL-7 expression by KGF in the intestine. METHODS: Intestinal epithelial cells (LoVo cells and adult C57BL/6J mice were treated with KGF. Epithelial cell proliferation was studied by flow cytometry for BrdU-incorporation and by immunohistochemistry for PCNA staining. Western blot was used to detect the changes of expression of P-Tyr-STAT1, STAT1, and IL-7 by inhibiting STAT1. Alterations of nuclear extracts and total proteins of IRF-1, IRF-2 and IL-7 following IRF-1 and IRF-2 RNA interference with KGF treatment were also measured with western blot. Moreover, IL-7 mRNA expressions were also detected by Real-time PCR and IL-7 protein level in culture supernatants was measured by enzyme linked immunosorbent assay(ELISA. RESULTS: KGF administration significantly increased LoVo cell proliferation and also increased intestinal wet weight, villus height, crypt depth and crypt cell proliferation in mice. KGF treatment led to increased levels of P-Tyr-STAT1, RAPA and AG490 both blocked P-Tyr-STAT1 and IL-7 expression in LoVo cells. IRF-1 and IRF-2 expression in vivo and in vitro were also up-regulated by KGF, and IL-7 expression was decreased after IRF-1 and IRF-2 expression was silenced by interfering RNA, respectively. CONCLUSION: KGF could up-regulate IL-7 expression through the STAT1/IRF-1, IRF-2 signaling pathway, which is a new insight in potential effects of KGF on the intestinal mucosal immune system.

  20. The influence of radiotherapy on IL-2 and IL-6 secretions of mucous membrane epithelial cells of wistar small intestine.

    Science.gov (United States)

    Liu, Bin; Li, Xiaoling; Ai, Fulu; Wang, Tianlu; Chen, Yun; Zhang, Hao

    2015-01-01

    The aim of the study was to investigate the influence of radiotherapy on IL-2 and IL-6 secretions of mucous epithelial cells of small intestine and the inhibition effect of deproteinized calf blood extractive (DCBE, also known as Actovegin in trade name) on apoptosis of mucous epithelial cells of small intestine. 50 wistars were randomly divided into 5 groups with 10 in each including normal group (NG), radiation group (RG), low-dose Actovegin group (L-AG), middle-dose Actovegin group (M-AG), and high-dose Actovegin (H-AG). High-energy X-ray linear accelerator was used for abdominal irradiation of RG, L-AG, M-AG, and H-AG at the exposure dose of 9.0 Gy to establish the wistar radiation damage model. Modeling wistars were injected with medicine for successive 4 days, and their small intestinal mucosas were extracted as pathological sections; then fully automated analyzer was employed to detect their IL-2 and IL-6 levels. Immunohistochemical analysis was carried out to explore the effect of Actovegin on apoptosis of mucous membrane epithelial cells of small intestine. The IL-2 and IL-6 levels of RG are significantly higher than other groups and differences are statistically significant (P 0.05). Compared with RG, the villus height, membrane thickness, crypt depth, and whole layer thickness significantly improved (P < 0.05). However, the expression levels of apoptosis-related protein bax of M-AG and H-AG are significantly lower than RG, and their bcl-2 levels are higher than RG with significant difference between them (P < 0.05). Actovegin is capable of effectively inhibiting the expression of apoptosis-related protein bax and facilitating the expression of anti-apoptosis protein bcl-2, having preferable remediation effect on mucous membrane epithelial cells of radioactive enteritis.

  1. Interactions of radiation and adriamycin, bleomycin, mitomycin C or cis-diamminedichloroplatinum II in intestinal crypt cells

    DEFF Research Database (Denmark)

    von der Maase, H

    1984-01-01

    The interactions of radiation and adriamycin (ADM), bleomycin (BLM), mitomycin C (MM-C), or cis-diamminedichloroplatinum II (cis-DDP) in mouse jejunal crypt cells were studied using the microcolony survival assay. ADM administered from 24 h before to 48 h after irradiation resulted in an almost...

  2. Effect of heat stress on intestinal barrier function of human intestinal epithelial Caco-2 cells

    Directory of Open Access Journals (Sweden)

    Gui-zhen XIAO

    2013-07-01

    Full Text Available Objective To investigate the heat stress-induced dysfunction of intestinal barrier including intestinal tight junction and apoptosis of epithelial cells. Methods Human intestinal epithelial Caco-2 cell monolayers, serving as the intestinal barrier model, were exposed to different temperature (37-43℃ for designated time. Transepithelial electrical resistance (TEER and horseradish peroxidase (HRP flux permeability were measured to evaluate barrier integrity. Level of tight junction (TJ protein occludin was analyzed by Western blotting. Cell apoptosis rate was determined using Annexin V-FITC/PI kit by flow cytometry. Results Compared with the 37℃ group, TEER lowered and the permeability for HRP increased significantly after heat exposure (P<0.01 in 39℃, 41℃ and 43℃ groups. The expression of occludin increased when the temperature was elevated from 37℃ to 41℃, and it reached the maximal level at 41℃. However, its expression gradually decreased with passage of time at 43℃. Cell apoptosis was enhanced with elevation of the temperature (P<0.05 or P<0.01. Conclusion Heat stress can induce damage to tight junction and enhance apoptosis of epithelial cells, thus causing dysfunction of intestinal epithelial barrier.

  3. The effect of dietary carbohydrates and Trichuris suis infection on pig large intestine tissue structure, epithelial cell proliferation and mucin characteristics.

    Science.gov (United States)

    Thomsen, L E; Knudsen, K E Bach; Hedemann, M S; Roepstorff, A

    2006-11-30

    Two experiments (Exps. 1 and 2) were performed to study the influence of Trichuris suis infection and type of dietary carbohydrates on large intestine morphology, epithelial cell proliferation and mucin characteristics. Two experimental diets based on barley flour were used; Diet 1 was supplemented with resistant carbohydrates from oat hull meal, while Diet 2 was supplemented with fermentable carbohydrates from sugar beet fibre and inulin. In Experiment 1, 32 pigs were allocated randomly into four groups. Two groups were fed Diet 1 and two groups Diet 2. Pigs from one of each diet group were inoculated with a single dose of 2000 infective T. suis eggs and the other two groups remained uninfected controls. In Experiment 2, 12 pigs were allocated randomly into two groups and fed Diet 1 or Diet 2, respectively, and inoculated with a single dose of 2000 infective T. suis eggs. All the pigs were slaughtered 8 weeks post inoculation (p.i.). The worm counts were lower in pigs fed Diet 2 in both experiments, but not significantly so. Both diet and infection status significantly influenced the tissue weight of the large intestine. In both experiments, pigs fed Diet 2 had heavier large intestines than pigs fed Diet 1 and in Experiment1 the infected pigs of both diets had heavier large intestines than their respective control groups. Diet and infection also significantly affected the morphological architecture and mucin production in both experiments. Pigs fed Diet 1 had larger crypts both in terms of area and height than pigs fed Diet 2 and T. suis infected pigs on both diets in Experiment 1 had larger crypts than their respective control groups. The area of the mucin granules in the crypts constituted 22-53% of the total crypt area and was greatest in the T. suis infected pigs fed Diet 1. Epithelial cell proliferation was affected neither by diet nor infection in any of the experiments. The study showed that both T. suis infection and dietary carbohydrates significantly

  4. Positive cross talk between protein kinase D and β-catenin in intestinal epithelial cells: impact on β-catenin nuclear localization and phosphorylation at Ser552.

    Science.gov (United States)

    Wang, Jia; Han, Liang; Sinnett-Smith, James; Han, Li-Li; Stevens, Jan V; Rozengurt, Nora; Young, Steven H; Rozengurt, Enrique

    2016-04-01

    Given the fundamental role of β-catenin signaling in intestinal epithelial cell proliferation and the growth-promoting function of protein kinase D1 (PKD1) in these cells, we hypothesized that PKDs mediate cross talk with β-catenin signaling. The results presented here provide several lines of evidence supporting this hypothesis. We found that stimulation of intestinal epithelial IEC-18 cells with the G protein-coupled receptor (GPCR) agonist angiotensin II (ANG II), a potent inducer of PKD activation, promoted endogenous β-catenin nuclear localization in a time-dependent manner. A significant increase was evident within 1 h of ANG II stimulation (Pnuclear localization and phosphorylation at Ser(552) in response to ANG II. GPCR stimulation also induced the formation of a complex between PKD1 and β-catenin, as shown by coimmunoprecipitation that depended on PKD1 catalytic activation, as it was abrogated by cell treatment with PKD family inhibitors. Using transgenic mice that express elevated PKD1 protein in the intestinal epithelium, we detected a marked increase in the localization of β-catenin in the nucleus of crypt epithelial cells in the ileum of PKD1 transgenic mice, compared with nontransgenic littermates. Collectively, our results identify a novel cross talk between PKD and β-catenin in intestinal epithelial cells, both in vitro and in vivo.

  5. Modulation of Intestinal Epithelial Defense Responses by Probiotic Bacteria.

    Science.gov (United States)

    Wan, L Y M; Chen, Z J; Shah, N P; El-Nezami, H

    2016-12-09

    Probiotics are live microorganisms, which when administered in food confer numerous health benefits. In previous studies about beneficial effects of probiotic bacteria to health, particularly in the fields of intestinal mucosa defense responses, specific probiotics, in a strain-dependent manner, show certain degree of potential to reinforce the integrity of intestinal epithelium and/or regulate some immune components. The mechanism of probiotic action is an area of interest. Among all possible routes of modulation by probiotics of intestinal epithelial cell-mediated defense responses, modulations of intestinal barrier function, innate, and adaptive mucosal immune responses, as well as signaling pathways are considered to play important role in the intestinal defense responses against pathogenic bacteria. This review summarizes the beneficial effects of probiotic bacteria to intestinal health together with the mechanisms affected by probiotic bacteria: barrier function, innate, and adaptive defense responses such as secretion of mucins, defensins, trefoil factors, immunoglobulin A (IgA), Toll-like receptors (TLRs), cytokines, gut associated lymphoid tissues, and signaling pathways.

  6. Lymphocyte Cc Chemokine Receptor 9 and Epithelial Thymus-Expressed Chemokine (Teck) Expression Distinguish the Small Intestinal Immune Compartment

    Science.gov (United States)

    Kunkel, Eric J.; Campbell, James J.; Haraldsen, Guttorm; Pan, Junliang; Boisvert, Judie; Roberts, Arthur I.; Ebert, Ellen C.; Vierra, Mark A.; Goodman, Stuart B.; Genovese, Mark C.; Wardlaw, Andy J.; Greenberg, Harry B.; Parker, Christina M.; Butcher, Eugene C.; Andrew, David P.; Agace, William W.

    2000-01-01

    The immune system has evolved specialized cellular and molecular mechanisms for targeting and regulating immune responses at epithelial surfaces. Here we show that small intestinal intraepithelial lymphocytes and lamina propria lymphocytes migrate to thymus-expressed chemokine (TECK). This attraction is mediated by CC chemokine receptor (CCR)9, a chemoattractant receptor expressed at high levels by essentially all CD4+ and CD8+ T lymphocytes in the small intestine. Only a small subset of lymphocytes in the colon are CCR9+, and lymphocytes from other tissues including tonsils, lung, inflamed liver, normal or inflamed skin, inflamed synovium and synovial fluid, breast milk, and seminal fluid are universally CCR9−. TECK expression is also restricted to the small intestine: immunohistochemistry reveals that intense anti-TECK reactivity characterizes crypt epithelium in the jejunum and ileum, but not in other epithelia of the digestive tract (including stomach and colon), skin, lung, or salivary gland. These results imply a restricted role for lymphocyte CCR9 and its ligand TECK in the small intestine, and provide the first evidence for distinctive mechanisms of lymphocyte recruitment that may permit functional specialization of immune responses in different segments of the gastrointestinal tract. Selective expression of chemokines by differentiated epithelium may represent an important mechanism for targeting and specialization of immune responses. PMID:10974041

  7. Oral insulin stimulates intestinal epithelial cell turnover following massive small bowel resection in a rat and a cell culture model.

    Science.gov (United States)

    Ben Lulu, Shani; Coran, Arnold G; Shehadeh, Naim; Shamir, Raanan; Mogilner, Jorge G; Sukhotnik, Igor

    2012-02-01

    We have recently reported that oral insulin (OI) stimulates intestinal adaptation after bowel resection and that OI enhances enterocyte turnover in correlation with insulin receptor expression along the villus-crypt axis. The purpose of the present study was to evaluate the effect of OI on intestinal epithelial cell proliferation and apoptosis in a rat model of short bowel syndrome (SBS) and in a cell culture model. Caco-2 cells were incubated with increasing concentrations of insulin. Cell proliferation and apoptosis were determined by FACS cytometry. Cell viability was investigated using the Alamar Blue technique. Male rats were divided into three groups: Sham rats underwent bowel transection, SBS rats underwent a 75% bowel resection, and SBS-OI rats underwent bowel resection and were treated with OI given in drinking water (1 U/ml) from the third postoperative day. Parameters of intestinal adaptation, enterocyte proliferation and apoptosis were determined on day 15. Real time PCR was used to determine the level of bax and bcl-2 mRNA and western blotting was used to determine bax, bcl-2, p-ERK and AKT protein levels. Statistical analysis was performed using the one-way ANOVA test, with P statistically significant. Treatment of Caco-2 cells with insulin resulted in a significant increase in cell proliferation (twofold increase after 24 h and 37% increase after 48 h) and cell viability (in a dose-dependent manner), but did not change cell apoptosis. In a rat model of SBS, treatment with OI resulted in a significant increase in all parameters of intestinal adaptation. Elevated cell proliferation rate in insulin treated rats was accompanied by elevated AKT and p-ERK protein levels. Decreased cell apoptosis in SBS-INS rats corresponded with a decreased bax/bcl-2 ratio. Oral insulin stimulates intestinal epithelial cell turnover after massive small bowel resection in a rat model of SBS and a cell culture model.

  8. Epithelial cell extrusion leads to breaches in the intestinal epithelium.

    Science.gov (United States)

    Liu, Julia J; Davis, Elisabeth M; Wine, Eytan; Lou, Yuefei; Rudzinski, Jan K; Alipour, Misagh; Boulanger, Pierre; Thiesen, Aducio L; Sergi, Consolato; Fedorak, Richard N; Muruve, Daniel; Madsen, Karen L; Irvin, Randall T

    2013-04-01

    Two distinct forms of intestinal epithelial cell (IEC) extrusion are described: 1 with preserved epithelial integrity and 1 that introduced breaches in the epithelial lining. In this study, we sought to determine the mechanism underlying the IEC extrusion that alters the permeability of the gut epithelium. IEC extrusions in polarized T84 monolayer were induced with nigericin. Epithelial permeability was assessed with transepithelial electrical resistance and movements of latex microspheres and green fluorescent protein-transfected Escherichia coli across the monolayer. In vivo IEC extrusion was modulated in wild-type and a colitic (interleukin-10 knock-out) mouse model with caspase-1 activation and inhibition. Luminal aspirates and mucosal biopsies from control patients and patients with inflammatory bowel disease were analyzed for caspase-1 and caspase-3&7 activation. Caspase-1-induced IEC extrusion in T84 monolayers resulted in dose-dependent and time-dependent barrier dysfunction, reversible with caspase-1 inhibition. Moreover, the movements of microspheres and microbes across the treated epithelial monolayers were observed. Increased caspase-1-mediated IEC extrusion in interleukin-10 knock-out mice corresponded to enhanced permeation of dextran, microspheres, and translocation of E. coli compared with wild type. Caspase-1 inhibition in interleukin-10 knock-out mice resulted in a time-dependent reduction in cell extrusion and normalization of permeability to microspheres. Increased IEC extrusion in wild-type mice was induced with caspase-1 activation. In human luminal aspirates, the ratio of positively stained caspase-1 to caspase-3&7 cells were 1:1 and 2:1 in control patients and patients with inflammatory bowel disease, respectively; these observations were confirmed by cytochemical analysis of mucosal biopsies. IEC extrusion mediated by caspase-1 activation contributes to altered intestinal permeability in vitro and in vivo.

  9. A microfluidic cell culture device (μFCCD) to culture epithelial cells with physiological and morphological properties that mimic those of the human intestine.

    Science.gov (United States)

    Chi, Meiying; Yi, Banya; Oh, Seunghan; Park, Dong-June; Sung, Jong Hwan; Park, Sungsu

    2015-01-01

    Physiological and morphological properties of the human intestine cannot be accurately mimicked in conventional culture devices such as well plates and petri dishes where intestinal epithelial cells form a monolayer with loose contacts among cells. Here, we report a novel microfluidic cell culture device (μFCCD) that can be used to culture cells as a human intestinal model. This device enables intestinal epithelial cells (Caco-2) to grow three-dimensionally on a porous membrane coated with fibronectin between two polydimethylsiloxane (PDMS) layers. Within 3 days, Caco-2 cells cultured in the μFCCD formed villi- and crypt-like structures with small intercellular spaces, while individual cells were tightly connected to one another through the expression of the tight junction protein occludin, and were covered with a secreted mucin, MUC-2. Caco-2 cells cultured in the μFCCD for 3 days were less susceptible to bacterial attack than those cultured in transwell plates for 21 days. μFCCD-cultured Caco-2 cells also displayed physiologically relevant absorption and paracellular transport properties. These results suggest that our intestinal model more accurately mimics the morphological and physiological properties of the intestine in vivo than the conventional transwell culture model.

  10. A strategy for isolation of cDNAs encoding proteins affecting human intestinal epithelial cell growth and differentiation: characterization of a novel gut-specific N-myristoylated annexin.

    Science.gov (United States)

    Wice, B M; Gordon, J I

    1992-01-01

    The human intestinal epithelium is rapidly and perpetually renewed as the descendants of multipotent stem cells located in crypts undergo proliferation, differentiation, and eventual exfoliation during a very well organized migration along the crypt to villus axis. The mechanisms that establish and maintain this balance between proliferation and differentiation are largely unknown. We have utilized HT-29 cells, derived from a human colon adenocarcinoma, as a model system for identifying gene products that may regulate these processes. Proliferating HT-29 cells cultured in the absence of glucose (e.g., using inosine as the carbon source) have some of the characteristics of undifferentiated but committed crypt epithelial cells while postconfluent cells cultured in the absence of glucose resemble terminally differentiated enterocytes or goblet cells. A cDNA library, constructed from exponentially growing HT-29 cells maintained in inosine-containing media, was sequentially screened with a series of probes depleted of sequences encoding housekeeping functions and enriched for intestine-specific sequences that are expressed in proliferating committed, but not differentiated, epithelial cells. Of 100,000 recombinant phage surveyed, one was found whose cDNA was derived from an apparently gut-specific mRNA. It encodes a 316 residue, 35,463-D protein that is a new member of the annexin/lipocortin family. Other family members have been implicated in regulation of cellular growth and in signal transduction pathways. RNA blot and in situ hybridization studies indicate that the gene encoding this new annexin exhibits region-specific expression along both axes of the human gut: (a) highest levels of mRNA are present in the jejunum with marked and progressive reductions occurring distally; (b) its mRNA appears in crypt-associated epithelial cells and increases in concentration as they exit the crypt. Villus-associated epithelial cells continue to transcribe this gene during their

  11. Mechanisms of Cell Polarity-Controlled Epithelial Homeostasis and Immunity in the Intestine

    NARCIS (Netherlands)

    Klunder, Leon J; Faber, Klaas Nico; Dijkstra, Gerard; van IJzendoorn, Sven C D

    2017-01-01

    Intestinal epithelial cell polarity is instrumental to maintain epithelial homeostasis and balance communications between the gut lumen and bodily tissue, thereby controlling the defense against gastrointestinal pathogens and maintenance of immune tolerance to commensal bacteria. In this review, we

  12. Radioprotection and Cell Cycle Arrest of Intestinal Epithelial Cells by Darinaparsin, a Tumor Radiosensitizer

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Junqiang; Doi, Hiroshi [Department of Radiation Oncology, School of Medicine, Stanford University, Stanford, California (United States); Saar, Matthias; Santos, Jennifer [Department of Urology, School of Medicine, Stanford University, Stanford, California (United States); Li, Xuejun; Peehl, Donna M. [Department of Radiation Oncology, School of Medicine, Stanford University, Stanford, California (United States); Knox, Susan J., E-mail: sknox@stanford.edu [Department of Radiation Oncology, School of Medicine, Stanford University, Stanford, California (United States)

    2013-12-01

    Purpose: It was recently reported that the organic arsenic compound darinaparsin (DPS) is a cytotoxin and radiosensitizer of tumor cells in vitro and in subcutaneous xenograft tumors. Surprisingly, it was also found that DPS protects normal intestinal crypt epithelial cells (CECs) from clonogenic death after ionizing radiation (IR). Here we tested the DPS radiosensitizing effect in a clinically relevant model of prostate cancer and explored the radioprotective effect and mechanism of DPS on CECs. Methods and Materials: The radiation modification effect of DPS was tested in a mouse model of orthotopic xenograft prostate cancer and of IR-induced acute gastrointestinal syndrome. The effect of DPS on CEC DNA damage and DNA damage responses was determined by immunohistochemistry. Results: In the mouse model of IR-induced gastrointestinal syndrome, DPS treatment before IR accelerated recovery from body weight loss and increased animal survival. DPS decreased post-IR DNA damage and cell death, suggesting that the radioprotective effect was mediated by enhanced DNA damage repair. Shortly after DPS injection, significant cell cycle arrest was observed in CECs at both G1/S and G2/M checkpoints, which was accompanied by the activation of cell cycle inhibitors p21 and growth arrest and DNA-damage-inducible protein 45 alpha (GADD45A). Further investigation revealed that DPS activated ataxia telangiectasia mutated (ATM), an important inducer of DNA damage repair and cell cycle arrest. Conclusions: DPS selectively radioprotected normal intestinal CECs and sensitized prostate cancer cells in a clinically relevant model. This effect may be, at least in part, mediated by DNA damage response activation and has the potential to significantly increase the therapeutic index of radiation therapy.

  13. The Inside Story of Shigella Invasion of Intestinal Epithelial Cells

    Science.gov (United States)

    Carayol, Nathalie; Tran Van Nhieu, Guy

    2013-01-01

    As opposed to other invasive pathogens that reside into host cells in a parasitic mode, Shigella, the causative agent of bacillary dysentery, invades the colonic mucosa but does not penetrate further to survive into deeper tissues. Instead, Shigella invades, replicates, and disseminates within the colonic mucosa. Bacterial invasion and spreading in intestinal epithelium lead to the elicitation of inflammatory responses responsible for the tissue destruction and shedding in the environment for further infection of other hosts. In this article, we highlight specific features of the Shigella arsenal of virulence determinants injected by a type III secretion apparatus (T3SA) that point to the targeting of intestinal epithelial cells as a discrete route of invasion during the initial event of the infectious process. PMID:24086068

  14. A two-dimensional model of the colonic crypt accounting for the role of the basement membrane and pericryptal fibroblast sheath.

    Directory of Open Access Journals (Sweden)

    Sara-Jane Dunn

    Full Text Available The role of the basement membrane is vital in maintaining the integrity and structure of an epithelial layer, acting as both a mechanical support and forming the physical interface between epithelial cells and the surrounding connective tissue. The function of this membrane is explored here in the context of the epithelial monolayer that lines the colonic crypt, test-tube shaped invaginations that punctuate the lining of the intestine and coordinate a regular turnover of cells to replenish the epithelial layer every few days. To investigate the consequence of genetic mutations that perturb the system dynamics and can lead to colorectal cancer, it must be possible to track the emerging tissue level changes that arise in the crypt. To that end, a theoretical crypt model with a realistic, deformable geometry is required. A new discrete crypt model is presented, which focuses on the interaction between cell- and tissue-level behaviour, while incorporating key subcellular components. The model contains a novel description of the role of the surrounding tissue and musculature, based upon experimental observations of the tissue structure of the crypt, which are also reported. A two-dimensional (2D cross-sectional geometry is considered, and the shape of the crypt is allowed to evolve and deform. Simulation results reveal how the shape of the crypt may contribute mechanically to the asymmetric division events typically associated with the stem cells at the base. The model predicts that epithelial cell migration may arise due to feedback between cell loss at the crypt collar and density-dependent cell division, an hypothesis which can be investigated in a wet lab. This work forms the basis for investigation of the deformation of the crypt structure that can occur due to proliferation of cells exhibiting mutant phenotypes, experiments that would not be possible in vivo or in vitro.

  15. CaSR function in the intestine: Hormone secretion, electrolyte absorption and secretion, paracrine non-canonical Wnt signaling and colonic crypt cell proliferation.

    Science.gov (United States)

    Macleod, R John

    2013-06-01

    Expression and function of the CaSR have been shown in some mammalian taste buds and basal cells of the esophagus. Signaling cascades responsible for CaSR-mediated stimulation of H(+)-K(+)-ATPase on human parietal cells have been defined. Transgenic mice and reductionistic cell culture models have shown that the CaSR promotes gastrin secretion from G cells, cholecystokinin (CCK) secretion from duodenal I cells and BMP-2 secretion from sub-epithelial myofibroblasts. In addition, the CaSR mediates a novel paracrine relationship between myofibroblasts and overlying epithelial cells in the colon. Thus, CaSR activators stimulate secretion of Wnt5a from myofibroblasts and expression of the Wnt5a receptor Ror2 in epithelial cells. CaSR-mediated Wnt5a/Ror2 engagement stimulates epithelial differentiation and reduces expression of the receptor for tumor necrosis factor (TNFR1). CaSR activators also modulate intestinal motility, inhibit Cl(-) secretion and stimulate Na(+) absorption in both the small intestine and colon. Colonic epithelia from conditional and global CaSR knockout mice exhibit increased proliferation with increased Wnt/β-catenin signaling, demonstrating that the CaSR negatively modulates colonic epithelial growth.

  16. Molecular cloning, sequence analysis, and function of the intestinal epithelial stem cell marker Bmi1 in pig intestinal epithelial cells.

    Science.gov (United States)

    Li, C-M; Yan, H-C; Fu, H-L; Xu, G-F; Wang, X-Q

    2014-01-01

    In the present work, we cloned the full-length cDNA of the pig Bmi1 gene (BMI1 polycomb ring finger oncogene), which has been indicated as an intestinal epithelial stem cell (IESC) marker in other mammals. This paper provides the first report of the function of Bmi1 in pig intestinal epithelial cells and a brief description of its underlying mechanism. Rapid amplification of cDNA ends technology was used to clone the complete pig Bmi1 sequence, and a Bmi1-pcDNA3.1 vector was constructed for transfection into an intestinal porcine epithelial cell line (IPEC-1). The proliferation ability of the cells was estimated using the MTT assay and the EdU incorporation method at different time points after seeding. Cell cycle information was detected by flow cytometry. The mRNA abundances of cell cycle-related genes were also measured. The results indicated that the pig Bmi1 cDNA is 3,193 bp in length and consists of a 981 bp open reading frame, a 256 bp 5´ untranslated region (UTR), and a 1,956 bp 3' UTR. The transcript contains no signal peptides, and there are no transmembrane regions in the pig Bmi1 coded protein, which has a total of 326 AA. The overexpression of the pig Bmi1 in the IPEC-1 cells led to increased cell proliferation and a lower percentage of cells in the G1 and S phases (P cells in the G2 phase (P 0.05). Our data suggested that pig Bmi1 can increase the proliferation of IPEC-1 cells by promoting the G1/S transition and the overall cell cycle process.

  17. Food-grade TiO2 impairs intestinal and systemic immune homeostasis, initiates preneoplastic lesions and promotes aberrant crypt development in the rat colon

    Science.gov (United States)

    Bettini, Sarah; Boutet-Robinet, Elisa; Cartier, Christel; Coméra, Christine; Gaultier, Eric; Dupuy, Jacques; Naud, Nathalie; Taché, Sylviane; Grysan, Patrick; Reguer, Solenn; Thieriet, Nathalie; Réfrégiers, Matthieu; Thiaudière, Dominique; Cravedi, Jean-Pierre; Carrière, Marie; Audinot, Jean-Nicolas; Pierre, Fabrice H.; Guzylack-Piriou, Laurence; Houdeau, Eric

    2017-01-01

    Food-grade titanium dioxide (TiO2) containing a nanoscale particle fraction (TiO2-NPs) is approved as a white pigment (E171 in Europe) in common foodstuffs, including confectionary. There are growing concerns that daily oral TiO2-NP intake is associated with an increased risk of chronic intestinal inflammation and carcinogenesis. In rats orally exposed for one week to E171 at human relevant levels, titanium was detected in the immune cells of Peyer’s patches (PP) as observed with the TiO2-NP model NM-105. Dendritic cell frequency increased in PP regardless of the TiO2 treatment, while regulatory T cells involved in dampening inflammatory responses decreased with E171 only, an effect still observed after 100 days of treatment. In all TiO2-treated rats, stimulation of immune cells isolated from PP showed a decrease in Thelper (Th)-1 IFN-γ secretion, while splenic Th1/Th17 inflammatory responses sharply increased. E171 or NM-105 for one week did not initiate intestinal inflammation, while a 100-day E171 treatment promoted colon microinflammation and initiated preneoplastic lesions while also fostering the growth of aberrant crypt foci in a chemically induced carcinogenesis model. These data should be considered for risk assessments of the susceptibility to Th17-driven autoimmune diseases and to colorectal cancer in humans exposed to TiO2 from dietary sources. PMID:28106049

  18. Serratia marcescens is injurious to intestinal epithelial cells.

    Science.gov (United States)

    Ochieng, John B; Boisen, Nadia; Lindsay, Brianna; Santiago, Araceli; Ouma, Collins; Ombok, Maurice; Fields, Barry; Stine, O Colin; Nataro, James P

    2014-01-01

    Diarrhea causes substantial morbidity and mortality in children in low-income countries. Although numerous pathogens cause diarrhea, the etiology of many episodes remains unknown. Serratia marcescens is incriminated in hospital-associated infections, and HIV/AIDS associated diarrhea. We have recently found that Serratia spp. may be found more commonly in the stools of patients with diarrhea than in asymptomatic control children. We therefore investigated the possible enteric pathogenicity of S. marcescens in vitro employing a polarized human colonic epithelial cell (T84) monolayer. Infected monolayers were assayed for bacterial invasion, transepithelial electrical resistance (TEER), cytotoxicity, interleukin-8 (IL-8) release and morphological changes by scanning electron microscopy. We observed significantly greater epithelial cell invasion by S. marcescens compared to Escherichia coli strain HS (p = 0.0038 respectively). Cell invasion was accompanied by reduction in TEER and secretion of IL-8. Lactate dehydrogenase (LDH) extracellular concentration rapidly increased within a few hours of exposure of the monolayer to S. marcescens. Scanning electron microscopy of S. marcescens-infected monolayers demonstrated destruction of microvilli and vacuolization. Our results suggest that S. marcescens interacts with intestinal epithelial cells in culture and induces dramatic alterations similar to those produced by known enteric pathogens.

  19. Culture of human intestinal epithelial cell using the dissociating enzyme thermolysin and endothelin-3

    Directory of Open Access Journals (Sweden)

    Z. Liu

    2010-05-01

    Full Text Available Epithelium, a highly dynamic system, plays a key role in the homeostasis of the intestine. However, thus far a human intestinal epithelial cell line has not been established in many countries. Fetal tissue was selected to generate viable cell cultures for its sterile condition, effective generation, and differentiated character. The purpose of the present study was to culture human intestinal epithelial cells by a relatively simple method. Thermolysin was added to improve the yield of epithelial cells, while endothelin-3 was added to stimulate their growth. By adding endothelin-3, the achievement ratio (viable cell cultures/total cultures was enhanced to 60% of a total of 10 cultures (initiated from 8 distinct fetal small intestines, allowing the generation of viable epithelial cell cultures. Western blot, real-time PCR and immunofluorescent staining showed that cytokeratins 8, 18 and mouse intestinal mucosa-1/39 had high expression levels in human intestinal epithelial cells. Differentiated markers such as sucrase-isomaltase, aminopeptidase N and dipeptidylpeptidase IV also showed high expression levels in human intestinal epithelial cells. Differentiated human intestinal epithelial cells, with the expression of surface markers (cytokeratins 8, 18 and mouse intestinal mucosa-1/39 and secretion of cytokines (sucrase-isomaltase, aminopeptidase N and dipeptidylpeptidase IV, may be cultured by the thermolysin and endothelin-3 method and maintained for at least 20 passages. This is relatively simple, requiring no sophisticated techniques or instruments, and may have a number of varied applications.

  20. Arginine consumption by the intestinal parasite Giardia intestinalis reduces proliferation of intestinal epithelial cells.

    Science.gov (United States)

    Stadelmann, Britta; Merino, María C; Persson, Lo; Svärd, Staffan G

    2012-01-01

    In the field of infectious diseases the multifaceted amino acid arginine has reached special attention as substrate for the hosts production of the antimicrobial agent nitric oxide (NO). A variety of infectious organisms interfere with this part of the host immune response by reducing the availability of arginine. This prompted us to further investigate additional roles of arginine during pathogen infections. As a model we used the intestinal parasite Giardia intestinalis that actively consumes arginine as main energy source and secretes an arginine-consuming enzyme, arginine deiminase (ADI). Reduced intestinal epithelial cell (IEC) proliferation is a common theme during bacterial and viral intestinal infections, but it has never been connected to arginine-consumption. Our specific question was thereby, whether the arginine-consumption by Giardia leads to reduced IEC proliferation, in addition to NO reduction. In vitro cultivation of human IEC lines in arginine-free or arginine/citrulline-complemented medium, as well as in interaction with different G. intestinalis isolates, were used to study effects on host cell replication by MTT assay. IEC proliferation was further analyzed by DNA content analysis, polyamine measurements and expressional analysis of cell cycle regulatory genes. IEC proliferation was reduced upon arginine-withdrawal and also in an arginine-dependent manner upon interaction with G. intestinalis or addition of Giardia ADI. We show that arginine-withdrawal by intestinal pathogens leads to a halt in the cell cycle in IECs through reduced polyamine levels and upregulated cell cycle inhibitory genes. This is of importance with regards to intestinal tissue homeostasis that is affected through reduced cell proliferation. Thus, the slower epithelial cell turnover helps the pathogen to maintain a more stable niche for colonization. This study also shows why supplementation therapy of diarrhea patients with arginine/citrulline is helpful and that

  1. Arginine consumption by the intestinal parasite Giardia intestinalis reduces proliferation of intestinal epithelial cells.

    Directory of Open Access Journals (Sweden)

    Britta Stadelmann

    Full Text Available In the field of infectious diseases the multifaceted amino acid arginine has reached special attention as substrate for the hosts production of the antimicrobial agent nitric oxide (NO. A variety of infectious organisms interfere with this part of the host immune response by reducing the availability of arginine. This prompted us to further investigate additional roles of arginine during pathogen infections. As a model we used the intestinal parasite Giardia intestinalis that actively consumes arginine as main energy source and secretes an arginine-consuming enzyme, arginine deiminase (ADI. Reduced intestinal epithelial cell (IEC proliferation is a common theme during bacterial and viral intestinal infections, but it has never been connected to arginine-consumption. Our specific question was thereby, whether the arginine-consumption by Giardia leads to reduced IEC proliferation, in addition to NO reduction. In vitro cultivation of human IEC lines in arginine-free or arginine/citrulline-complemented medium, as well as in interaction with different G. intestinalis isolates, were used to study effects on host cell replication by MTT assay. IEC proliferation was further analyzed by DNA content analysis, polyamine measurements and expressional analysis of cell cycle regulatory genes. IEC proliferation was reduced upon arginine-withdrawal and also in an arginine-dependent manner upon interaction with G. intestinalis or addition of Giardia ADI. We show that arginine-withdrawal by intestinal pathogens leads to a halt in the cell cycle in IECs through reduced polyamine levels and upregulated cell cycle inhibitory genes. This is of importance with regards to intestinal tissue homeostasis that is affected through reduced cell proliferation. Thus, the slower epithelial cell turnover helps the pathogen to maintain a more stable niche for colonization. This study also shows why supplementation therapy of diarrhea patients with arginine/citrulline is helpful

  2. Genomic dissection of conserved transcriptional regulation in intestinal epithelial cells

    Science.gov (United States)

    Camp, J. Gray; Weiser, Matthew; Cocchiaro, Jordan L.; Kingsley, David M.; Furey, Terrence S.; Sheikh, Shehzad Z.; Rawls, John F.

    2017-01-01

    The intestinal epithelium serves critical physiologic functions that are shared among all vertebrates. However, it is unknown how the transcriptional regulatory mechanisms underlying these functions have changed over the course of vertebrate evolution. We generated genome-wide mRNA and accessible chromatin data from adult intestinal epithelial cells (IECs) in zebrafish, stickleback, mouse, and human species to determine if conserved IEC functions are achieved through common transcriptional regulation. We found evidence for substantial common regulation and conservation of gene expression regionally along the length of the intestine from fish to mammals and identified a core set of genes comprising a vertebrate IEC signature. We also identified transcriptional start sites and other putative regulatory regions that are differentially accessible in IECs in all 4 species. Although these sites rarely showed sequence conservation from fish to mammals, surprisingly, they drove highly conserved IEC expression in a zebrafish reporter assay. Common putative transcription factor binding sites (TFBS) found at these sites in multiple species indicate that sequence conservation alone is insufficient to identify much of the functionally conserved IEC regulatory information. Among the rare, highly sequence-conserved, IEC-specific regulatory regions, we discovered an ancient enhancer upstream from her6/HES1 that is active in a distinct population of Notch-positive cells in the intestinal epithelium. Together, these results show how combining accessible chromatin and mRNA datasets with TFBS prediction and in vivo reporter assays can reveal tissue-specific regulatory information conserved across 420 million years of vertebrate evolution. We define an IEC transcriptional regulatory network that is shared between fish and mammals and establish an experimental platform for studying how evolutionarily distilled regulatory information commonly controls IEC development and physiology. PMID

  3. miR-200b inhibits TNF-α-induced IL-8 secretion and tight junction disruption of intestinal epithelial cells in vitro.

    Science.gov (United States)

    Shen, Yujie; Zhou, Min; Yan, Junkai; Gong, Zizhen; Xiao, Yongtao; Zhang, Cong; Du, Peng; Chen, Yingwei

    2017-02-01

    Inflammatory bowel diseases (IBDs) are chronic, inflammatory disorders of the gastrointestinal tract with unclear etiologies. Intestinal epithelial cells (IECs), containing crypt and villus enterocytes, occupy a critical position in the pathogenesis of IBDs and are a major producer of immunoregulatory cytokines and a key component of the intact epithelial barrier. Previously, we have reported that miR-200b is involved in the progression of IBDs and might maintain the integrity of the intestinal epithelial barrier via reducing the loss of enterocytes. In this study, we further investigated the impact of miR-200b on intestinal epithelial inflammation and tight junctions in two distinct differentiated states of Caco-2 cells after TNF-α treatment. We demonstrated that TNF-α-enhanced IL-8 expression was decreased by microRNA (miR)-200b in undifferentiated IECs. Simultaneously, miR-200b could alleviate TNF-α-induced tight junction (TJ) disruption in well-differentiated IECs by reducing the reduction in the transepithelial electrical resistance (TEER), inhibiting the increase in paracellular permeability, and preventing the morphological redistribution of the TJ proteins claudin 1 and ZO-1. The expression levels of the JNK/c-Jun/AP-1 and myosin light chain kinase (MLCK)/phosphorylated myosin light chain (p-MLC) pathways were attenuated in undifferentiated and differentiated enterocytes, respectively. Furthermore, a dual-luciferase reporter gene detection system provided direct evidence that c-Jun and MLCK were the specific targets of miR-200b. Collectively, our results highlighted that miR-200b played a positive role in IECs via suppressing intestinal epithelial IL-8 secretion and attenuating TJ damage in vitro, which suggested that miR-200b might be a promising strategy for IBD therapy.

  4. Activation of intestinal epithelial Stat3 orchestrates tissue defense during gastrointestinal infection.

    Directory of Open Access Journals (Sweden)

    Nadine Wittkopf

    Full Text Available Gastrointestinal infections with EHEC and EPEC are responsible for outbreaks of diarrheal diseases and represent a global health problem. Innate first-line-defense mechanisms such as production of mucus and antimicrobial peptides by intestinal epithelial cells are of utmost importance for host control of gastrointestinal infections. For the first time, we directly demonstrate a critical role for Stat3 activation in intestinal epithelial cells upon infection of mice with Citrobacter rodentium - a murine pathogen that mimics human infections with attaching and effacing Escherichia coli. C. rodentium induced transcription of IL-6 and IL-22 in gut samples of mice and was associated with activation of the transcription factor Stat3 in intestinal epithelial cells. C. rodentium infection induced expression of several antimicrobial peptides such as RegIIIγ and Pla2g2a in the intestine which was critically dependent on Stat3 activation. Consequently, mice with specific deletion of Stat3 in intestinal epithelial cells showed increased susceptibility to C. rodentium infection as indicated by high bacterial load, severe gut inflammation, pronounced intestinal epithelial cell death and dissemination of bacteria to distant organs. Together, our data implicate an essential role for Stat3 activation in intestinal epithelial cells during C. rodentium infection. Stat3 concerts the host response to bacterial infection by controlling bacterial growth and suppression of apoptosis to maintain intestinal epithelial barrier function.

  5. Effect of Dachengqi Tang(大承气汤)Granule on Proliferation of Intestinal Epithelial Cells in Rats with Experimental Intestinal Obstruction

    Institute of Scientific and Technical Information of China (English)

    KANGYi; LINXiu-zhen

    2003-01-01

    Objective:To study the effects of Dachengqi Tang(DCQT) granule on the proliferation of the intestinal epithelial cells in rats with experimental intestinal obstruction.Methods:Experimental intes-tinal obstruction models were established in rats and autoradiography with 3H-TdR was used to determine 3H-TdR labeling counts of intestinal epithelial cells in rats.Results:DCQT granule had no effects on 3H-TdR labeling counts of intestinal epithelial cells in normal rats.DCQT granule obviously increases the rate of renovation in intestinal epithelial cells of the intestinal obstruction rats.Conclusion:DCQT granule could reinforce the intestinal mucosa's defensive function by means of increasing the proliferation of intesti-nal epithelial cells.

  6. Effect of Dachengqi Tang (大承气汤) Granule on Proliferation of Intestinal Epithelial Cells in Rats with Experimental Intestinal Obstruction

    Institute of Scientific and Technical Information of China (English)

    康毅; 林秀珍

    2003-01-01

    Objective: To study the effects of Dachengqi Tang (DCQT) granule on the proliferation of the intestinal epithelial cells in rats with experimental intestinal obstruction. Methods: Experimental intestinal obstruction models were established in rats and autoradiography with 3H-TdR was used to determine 3H-TdR labeling counts of intestinal epithelial cells in rats. Results: DCQT granule had no effects on 3H-TdR labeling counts of intestinal epithelial cells in normal rats. DCQT granule obviously increases the rate of renovation in intestinal epithelial cells of the intestinal obstruction rats. Conclusion: DCQT granule could reinforce the intestinal mucosa's defensive function by means of increasing the proliferation of intestinal epithelial cells.

  7. Exogenous sphingomyelinase causes impaired intestinal epithelial barrier function

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    AIM: To test the hypothesis that hydrolysis of sphingomyelin to ceramide changes the composition of tight junctions (TJs) with increasing permeability of the intestinal epithelium.METHODS: Monolayers of Caco-2 cells were used as an in vitro model for the intestinal barrier. Permeability was determined by quantification of transepithelial flux and transepithelial resistance. Sphingolipid-rich membrane microdomains were isolated by a discontinuous sucrose gradient and characterized by Western-blot. Lipid content of microdomains was analysed by tandem mass spectrometry. Ceramide was subcellularly localized by immunofluorescent staining.RESULTS: Exogenous sphingomyelinase increased transepithelial permeability and decreased transepithelial resistance at concentrations as low as 0.01 U/mL.Lipid analysis showed rapid accumulation of ceramide in the membrane fractions containing occludin and claudin-4, representing TJs. In these fractions we observed a concomitant decrease of sphingomyelin and cholesterol with increasing concentrations of ceramide.Immunofluorescent staining confirmed clustering of ceramide at the sites of cell-cell contacts. Neutralization of surface ceramide prevented the permeability-increase induced by platelet activating factor.CONCLUSION: Our findings indicate that changes in lipid composition of TJs impair epithelial barrier functions. Generation of ceramide by sphingomyelinases might contribute to disturbed barrier function seen in diseases such as inflammatory, infectious, toxic or radiogenic bowel disease.

  8. Actin-interacting protein 1 controls assembly and permeability of intestinal epithelial apical junctions.

    Science.gov (United States)

    Lechuga, Susana; Baranwal, Somesh; Ivanov, Andrei I

    2015-05-01

    Adherens junctions (AJs) and tight junctions (TJs) are crucial regulators of the integrity and restitution of the intestinal epithelial barrier. The structure and function of epithelial junctions depend on their association with the cortical actin cytoskeleton that, in polarized epithelial cells, is represented by a prominent perijunctional actomyosin belt. The assembly and stability of the perijunctional cytoskeleton is controlled by constant turnover (disassembly and reassembly) of actin filaments. Actin-interacting protein (Aip) 1 is an emerging regulator of the actin cytoskeleton, playing a critical role in filament disassembly. In this study, we examined the roles of Aip1 in regulating the structure and remodeling of AJs and TJs in human intestinal epithelium. Aip1 was enriched at apical junctions in polarized human intestinal epithelial cells and normal mouse colonic mucosa. Knockdown of Aip1 by RNA interference increased the paracellular permeability of epithelial cell monolayers, decreased recruitment of AJ/TJ proteins to steady-state intercellular contacts, and attenuated junctional reassembly in a calcium-switch model. The observed defects of AJ/TJ structure and functions were accompanied by abnormal organization and dynamics of the perijunctional F-actin cytoskeleton. Moreover, loss of Aip1 impaired the apico-basal polarity of intestinal epithelial cell monolayers and inhibited formation of polarized epithelial cysts in 3-D Matrigel. Our findings demonstrate a previously unanticipated role of Aip1 in regulating the structure and remodeling of intestinal epithelial junctions and early steps of epithelial morphogenesis.

  9. Transcriptome changes during intestinal cell differentiation

    DEFF Research Database (Denmark)

    Tadjali, Mehrdad; Seidelin, Jakob B; Olsen, Jørgen

    2002-01-01

    The expression of 18149 genes have been analysed during the differentiation of the human intestinal cell line Caco-2. cDNA probes from undifferentiated and differentiated Caco-2 cells were separately hybridised to EST DNAs spotted in an array on a nylon membrane. A remarkable change...... by a general down-regulation of genes in the low abundance class. Similar results were found using mouse small intestinal crypt and villus cells, suggesting that the phenomenon also occurs in the intestine in vivo. The expression data were subsequently used in a search for markers for subsets of epithelial...... cells by performing reverse transcriptase-polymerase chain reaction on RNA extracted from laser dissected intestinal crypt and villi. In a screen of eight transcripts one - SART3 - was identified as a marker for human colonic crypts....

  10. GATA4 and GATA6 regulate intestinal epithelial cytodifferentiation during development.

    Science.gov (United States)

    Walker, Emily M; Thompson, Cayla A; Battle, Michele A

    2014-08-15

    The intestinal epithelium performs vital roles in organ function by absorbing nutrients and providing a protective barrier. The zinc-finger containing transcription factors GATA4 and GATA6 regulate enterocyte gene expression and control regional epithelial cell identity in the adult intestinal epithelium. Although GATA4 and GATA6 are expressed in the developing intestine, loss of either factor alone during the period of epithelial morphogenesis and cytodifferentiation fails to disrupt these processes. Therefore, we tested the hypothesis that GATA4 and GATA6 function redundantly to control these aspects of intestinal development. We used Villin-Cre, which deletes specifically in the intestinal epithelium during the period of villus development and epithelial cytodifferentiation, to generate Gata4Gata6 double conditional knockout embryos. Mice lacking GATA4 and GATA6 in the intestinal epithelium died within 24h of birth. At E18.5, intestinal villus architecture and epithelial cell populations were altered. Enterocytes were lost, and goblet cells were increased. Proliferation was also increased in GATA4-GATA6 deficient intestinal epithelium. Although villus morphology appeared normal at E16.5, the first time at which both Gata4 and Gata6 were efficiently reduced, changes in expression of markers of enterocytes, goblet cells, and proliferative cells were detected. Moreover, goblet cell number was increased at E16.5. Expression of the Notch ligand Dll1 and the Notch target Olfm4 were reduced in mutant tissue indicating decreased Notch signaling. Finally, we found that GATA4 occupies chromatin near the Dll1 transcription start site suggesting direct regulation of Dll1 by GATA4. We demonstrate that GATA4 and GATA6 play an essential role in maintaining proper intestinal epithelial structure and in regulating intestinal epithelial cytodifferentiation. Our data highlight a novel role for GATA factors in fine tuning Notch signaling during intestinal epithelial development to

  11. The role of the Hes1 crosstalk hub in Notch-Wnt interactions of the intestinal crypt.

    Science.gov (United States)

    Kay, Sophie K; Harrington, Heather A; Shepherd, Sarah; Brennan, Keith; Dale, Trevor; Osborne, James M; Gavaghan, David J; Byrne, Helen M

    2017-02-28

    The Notch pathway plays a vital role in determining whether cells in the intestinal epithelium adopt a secretory or an absorptive phenotype. Cell fate specification is coordinated via Notch's interaction with the canonical Wnt pathway. Here, we propose a new mathematical model of the Notch and Wnt pathways, in which the Hes1 promoter acts as a hub for pathway crosstalk. Computational simulations of the model can assist in understanding how healthy intestinal tissue is maintained, and predict the likely consequences of biochemical knockouts upon cell fate selection processes. Chemical reaction network theory (CRNT) is a powerful, generalised framework which assesses the capacity of our model for monostability or multistability, by analysing properties of the underlying network structure without recourse to specific parameter values or functional forms for reaction rates. CRNT highlights the role of β-catenin in stabilising the Notch pathway and damping oscillations, demonstrating that Wnt-mediated actions on the Hes1 promoter can induce dynamic transitions in the Notch system, from multistability to monostability. Time-dependent model simulations of cell pairs reveal the stabilising influence of Wnt upon the Notch pathway, in which β-catenin- and Dsh-mediated action on the Hes1 promoter are key in shaping the subcellular dynamics. Where Notch-mediated transcription of Hes1 dominates, there is Notch oscillation and maintenance of fate flexibility; Wnt-mediated transcription of Hes1 favours bistability akin to cell fate selection. Cells could therefore regulate the proportion of Wnt- and Notch-mediated control of the Hes1 promoter to coordinate the timing of cell fate selection as they migrate through the intestinal epithelium and are subject to reduced Wnt stimuli. Furthermore, mutant cells characterised by hyperstimulation of the Wnt pathway may, through coupling with Notch, invert cell fate in neighbouring healthy cells, enabling an aberrant cell to maintain its

  12. The Intestinal Wnt/TCF Signature

    NARCIS (Netherlands)

    Flier, L.G. van der; Sabates-Bellver, J.; Oving, I.; Haegebarth, A.; Palo, M. de; Anti, M.; Gijn, M.E. van; Suijkerbuijk, S; Wetering, M. van de; Marra, G.; Clevers, J.C.

    2007-01-01

    BACKGROUND & AIMS: In colorectal cancer, activating mutations in the Wnt pathway transform epithelial cells through the inappropriate expression of a TCF4 target gene program, which is physiologically expressed in intestinal crypts. METHODS: We have now performed an exhaustive array-based analysis o

  13. Fusion of intestinal epithelial cells with bone marrow derived cells is dispensable for tissue homeostasis.

    Science.gov (United States)

    de Jong, Joan H; Rodermond, Hans M; Zimberlin, Cheryl D; Lascano, Valeria; De Sousa E Melo, Felipe; Richel, Dick J; Medema, Jan Paul; Vermeulen, Louis

    2012-01-01

    The epithelial lining of the intestine is characterized by an immense cellular turn-over ascertaining an extensive regenerative capacity. Multiple reports suggest that besides the local intestinal stem cell pool, circulating cells of bone marrow origin (BMDCs) contribute to this process by fusing with the epithelial lineage. However, the functional relevance of these observations is unknown. In the present study we employ a model system in which we cannot only detect cell fusion but also examine the functional importance of this process in vivo. Our results indicate that fusion between BMDCs and intestinal epithelial cells is an extremely rare event under physiological conditions. More importantly, by employing a system in which fusion-derived cells can be specifically deleted after extensive tissue damage, we present evidence that cell fusion is not relevant for tissue regeneration. Our data decisively demonstrates that intestinal epithelial homeostasis and regeneration is not dependent on cell fusion involving BMDCs.

  14. MicroRNAs control intestinal epithelial differentiation, architecture, and barrier function.

    Science.gov (United States)

    McKenna, Lindsay B; Schug, Jonathan; Vourekas, Anastassios; McKenna, Jaime B; Bramswig, Nuria C; Friedman, Joshua R; Kaestner, Klaus H

    2010-11-01

    Whereas the importance of microRNA (miRNA) for the development of several tissues is well established, its role in the intestine is unknown. We aimed to quantify the complete miRNA expression profile of the mammalian intestinal mucosa and to determine the contribution of miRNAs to intestinal homeostasis using genetic means. We determined the miRNA transcriptome of the mouse intestinal mucosa using ultrahigh throughput sequencing. Using high-throughput sequencing of RNA isolated by cross-linking immunoprecipitation (HITS-CLIP), we identified miRNA-messenger RNA target relationships in the jejunum. We employed gene ablation of the obligatory miRNA-processing enzyme Dicer1 to derive mice deficient for all miRNAs in intestinal epithelia. miRNA abundance varies dramatically in the intestinal mucosa, from 1 read per million to 250,000. Of the 453 miRNA families identified, mmu-miR-192 is the most highly expressed in both the small and large intestinal mucosa, and there is a 53% overlap in the top 15 expressed miRNAs between the 2 tissues. The intestinal epithelium of Dicer1(loxP/loxP);Villin-Cre mutant mice is disorganized, with a decrease in goblet cells, a dramatic increase in apoptosis in crypts of both jejunum and colon, and accelerated jejunal cell migration. Furthermore, intestinal barrier function is impaired in Dicer1-deficient mice, resulting in intestinal inflammation with lymphocyte and neutrophil infiltration. Our list of miRNA-messenger RNA targeting relationships in the small intestinal mucosa provides insight into the molecular mechanisms behind the phenotype of Dicer1 mutant mice. We have identified all intestinal miRNAs and shown using gene ablation of Dicer1 that miRNAs play a vital role in the differentiation and function of the intestinal epithelium. Copyright © 2010 AGA Institute. Published by Elsevier Inc. All rights reserved.

  15. Intestinal epithelial HuR modulates distinct pathways of proliferation and apoptosis and attenuates small intestinal and colonic tumor development.

    Science.gov (United States)

    Giammanco, Antonina; Blanc, Valerie; Montenegro, Grace; Klos, Coen; Xie, Yan; Kennedy, Susan; Luo, Jianyang; Chang, Sung-Hee; Hla, Timothy; Nalbantoglu, Ilke; Dharmarajan, Sekhar; Davidson, Nicholas O

    2014-09-15

    HuR is a ubiquitous nucleocytoplasmic RNA-binding protein that exerts pleiotropic effects on cell growth and tumorigenesis. In this study, we explored the impact of conditional, tissue-specific genetic deletion of HuR on intestinal growth and tumorigenesis in mice. Mice lacking intestinal expression of HuR (Hur (IKO) mice) displayed reduced levels of cell proliferation in the small intestine and increased sensitivity to doxorubicin-induced acute intestinal injury, as evidenced by decreased villus height and a compensatory shift in proliferating cells. In the context of Apc(min/+) mice, a transgenic model of intestinal tumorigenesis, intestinal deletion of the HuR gene caused a three-fold decrease in tumor burden characterized by reduced proliferation, increased apoptosis, and decreased expression of transcripts encoding antiapoptotic HuR target RNAs. Similarly, Hur(IKO) mice subjected to an inflammatory colon carcinogenesis protocol [azoxymethane and dextran sodium sulfate (AOM-DSS) administration] exhibited a two-fold decrease in tumor burden. Hur(IKO) mice showed no change in ileal Asbt expression, fecal bile acid excretion, or enterohepatic pool size that might explain the phenotype. Moreover, none of the HuR targets identified in Apc(min/+)Hur(IKO) were altered in AOM-DSS-treated Hur(IKO) mice, the latter of which exhibited increased apoptosis of colonic epithelial cells, where elevation of a unique set of HuR-targeted proapoptotic factors was documented. Taken together, our results promote the concept of epithelial HuR as a contextual modifier of proapoptotic gene expression in intestinal cancers, acting independently of bile acid metabolism to promote cancer. In the small intestine, epithelial HuR promotes expression of prosurvival transcripts that support Wnt-dependent tumorigenesis, whereas in the large intestine epithelial HuR indirectly downregulates certain proapoptotic RNAs to attenuate colitis-associated cancer. Cancer Res; 74(18); 5322-35. ©2014 AACR.

  16. Intestinal subepithelial myofibroblasts support in vitro and in vivo growth of human small intestinal epithelium.

    Directory of Open Access Journals (Sweden)

    Nicholas Lahar

    Full Text Available The intestinal crypt-niche interaction is thought to be essential to the function, maintenance, and proliferation of progenitor stem cells found at the bases of intestinal crypts. These stem cells are constantly renewing the intestinal epithelium by sending differentiated cells from the base of the crypts of Lieberkühn to the villus tips where they slough off into the intestinal lumen. The intestinal niche consists of various cell types, extracellular matrix, and growth factors and surrounds the intestinal progenitor cells. There have recently been advances in the understanding of the interactions that regulate the behavior of the intestinal epithelium and there is great interest in methods for isolating and expanding viable intestinal epithelium. However, there is no method to maintain primary human small intestinal epithelium in culture over a prolonged period of time. Similarly no method has been published that describes isolation and support of human intestinal epithelium in an in vivo model. We describe a technique to isolate and maintain human small intestinal epithelium in vitro from surgical specimens. We also describe a novel method to maintain human intestinal epithelium subcutaneously in a mouse model for a prolonged period of time. Our methods require various growth factors and the intimate interaction between intestinal sub-epithelial myofibroblasts (ISEMFs and the intestinal epithelial cells to support the epithelial in vitro and in vivo growth. Absence of these myofibroblasts precluded successful maintenance of epithelial cell formation and proliferation beyond just a few days, even in the presence of supportive growth factors. We believe that the methods described here can be used to explore the molecular basis of human intestinal stem cell support, maintenance, and growth.

  17. Characteristic and functional analysis of a newly established porcine small intestinal epithelial cell line.

    Directory of Open Access Journals (Sweden)

    Jing Wang

    Full Text Available The mucosal surface of intestine is continuously exposed to both potential pathogens and beneficial commensal microorganisms. Recent findings suggest that intestinal epithelial cells, which once considered as a simple physical barrier, are a crucial cell lineage necessary for maintaining intestinal immune homeostasis. Therefore, establishing a stable and reliable intestinal epithelial cell line for future research on the mucosal immune system is necessary. In the present study, we established a porcine intestinal epithelial cell line (ZYM-SIEC02 by introducing the human telomerase reverse transcriptase (hTERT gene into small intestinal epithelial cells derived from a neonatal, unsuckled piglet. Morphological analysis revealed a homogeneous cobblestone-like morphology of the epithelial cell sheets. Ultrastructural indicated the presence of microvilli, tight junctions, and a glandular configuration typical of the small intestine. Furthermore, ZYM-SIEC02 cells expressed epithelial cell-specific markers including cytokeratin 18, pan-cytokeratin, sucrase-isomaltase, E-cadherin and ZO-1. Immortalized ZYM-SIEC02 cells remained diploid and were not transformed. In addition, we also examined the host cell response to Salmonella and LPS and verified the enhanced expression of mRNAs encoding IL-8 and TNF-α by infection with Salmonella enterica serovars Typhimurium (S. Typhimurium. Results showed that IL-8 protein expression were upregulated following Salmonella invasion. TLR4, TLR6 and IL-6 mRNA expression were upregulated following stimulation with LPS, ZYM-SIEC02 cells were hyporeponsive to LPS with respect to IL-8 mRNA expression and secretion. TNFα mRNA levels were significantly decreased after LPS stimulation and TNF-α secretion were not detected challenged with S. Typhimurium neither nor LPS. Taken together, these findings demonstrate that ZYM-SIEC02 cells retained the morphological and functional characteristics typical of primary swine

  18. Adult stem cells in the small intestine are intrinsically programmed with their location-specific function

    NARCIS (Netherlands)

    Middendorp, Sabine; Schneeberger, Kerstin; Wiegerinck, Caroline L; Mokry, Michal; Akkerman, Ronald D L; van Wijngaarden, Simone; Clevers, Hans; Nieuwenhuis, Edward E S

    Differentiation and specialization of epithelial cells in the small intestine are regulated in two ways. First, there is differentiation along the crypt-villus axis of the intestinal stem cells into absorptive enterocytes, Paneth, goblet, tuft, enteroendocrine, or M cells, which is mainly regulated

  19. Effects of Weaning on Intestinal Upper Villus Epithelial Cells of Piglets.

    Directory of Open Access Journals (Sweden)

    Huansheng Yang

    Full Text Available The intestinal upper villus epithelial cells represent the differentiated epithelial cells and play key role in digesting and absorbing lumenal nutrients. Weaning stress commonly results in a decrease in villus height and intestinal dysfunction in piglets. However, no study have been conducted to test the effects of weaning on the physiology and functions of upper villus epithelial cells. A total of 40 piglets from 8 litters were weaned at 14 days of age and one piglet from each litter was killed at 0 d (w0d, 1 d (w1d, 3 d (w3d, 5 d (w5d, and 7 d (w7d after weaning, respectively. The upper villus epithelial cells in mid-jejunum were isolated using the distended intestinal sac method. The expression of proteins in upper villus epithelial cells was analyzed using the isobaric tags for relative and absolute quantification or Western blotting. The expression of proteins involved in energy metabolism, Golgi vesicle transport, protein amino acid glycosylation, secretion by cell, transmembrane transport, ion transport, nucleotide catabolic process, translational initiation, and epithelial cell differentiation and apoptosis, was mainly reduced during the post-weaning period, and these processes may be regulated by mTOR signaling pathway. These results indicated that weaning inhibited various cellular processes in jejunal upper villus epithelial cells, and provided potential new directions for exploring the effects of weaning on the functions of intestine and improving intestinal functions in weaning piglets.

  20. TLR2 mediates gap junctional intercellular communication through connexin-43 in intestinal epithelial barrier injury.

    Science.gov (United States)

    Ey, Birgit; Eyking, Annette; Gerken, Guido; Podolsky, Daniel K; Cario, Elke

    2009-08-14

    Gap junctional intercellular communication (GJIC) coordinates cellular functions essential for sustaining tissue homeostasis; yet its regulation in the intestine is not well understood. Here, we identify a novel physiological link between Toll-like receptor (TLR) 2 and GJIC through modulation of Connexin-43 (Cx43) during acute and chronic inflammatory injury of the intestinal epithelial cell (IEC) barrier. Data from in vitro studies reveal that TLR2 activation modulates Cx43 synthesis and increases GJIC via Cx43 during IEC injury. The ulcerative colitis-associated TLR2-R753Q mutant targets Cx43 for increased proteasomal degradation, impairing TLR2-mediated GJIC during intestinal epithelial wounding. In vivo studies using mucosal RNA interference show that TLR2-mediated mucosal healing depends functionally on intestinal epithelial Cx43 during acute inflammatory stress-induced damage. Mice deficient in TLR2 exhibit IEC-specific alterations in Cx43, whereas administration of a TLR2 agonist protects GJIC by blocking accumulation of Cx43 and its hyperphosphorylation at Ser368 to prevent spontaneous chronic colitis in MDR1alpha-deficient mice. Finally, adding the TLR2 agonist to three-dimensional intestinal mucosa-like cultures of human biopsies preserves intestinal epithelial Cx43 integrity and polarization ex vivo. In conclusion, Cx43 plays an important role in innate immune control of commensal-mediated intestinal epithelial wound repair.

  1. Intestinal D-glucose transport and membrane fluidity along crypt-villus axis of streptozocin-induced diabetic rats.

    Science.gov (United States)

    Dudeja, P K; Wali, R K; Klitzke, A; Brasitus, T A

    1990-10-01

    Diabetes was induced in male Lewis rats by a single injection of streptozocin (50 mg/kg body wt ip). After 10-14 days, diabetic and age- and sex-matched control animals were killed, and their proximal small intestines were removed. Villus-tip, mid-villus, and lower-villus enterocytes were harvested from each group with a method that combined divalent cation chelation with mild mechanical dissociation. These fractions were used as starting material to prepare brush-border membrane vesicles. Preparations from each of these fractions were then analyzed and compared with respect to their Na(+)-gradient-dependent and Na(+)-independent D-glucose transport, lipid fluidity, and lipid composition. The results of these experiments demonstrated that 1) maximum rates of Na(+)-gradient-dependent D-glucose transport (Vmax) were greatest in membrane vesicles prepared from mature cells (villus tip and mid villus) of control rats; 2) the glucose concentration producing half-maximal rates of transport (Km), however, was significantly lower in lower-villus membrane vesicles of control rats, suggesting that a distinct glucose transporter existed in the membranes of these relatively immature enterocytes; 3) Na(+)-gradient-dependent, but not Na(+)-independent, D-glucose uptake was greater in diabetic membrane vesicles prepared from mid-villus and lower-villus fractions but not in vesicles prepared from villus-tip cells; and 4) no obvious relationship between alterations in membrane lipid fluidity and enhanced uptake of Na(+)-gradient-dependent D-glucose by these transporter(s) could be established in this experimental model of acute diabetes mellitus.

  2. Peroxisomes in intestinal and gallbladder epithelial cells of the stickleback, Gasterosteus aculeatus L. (Teleostei)

    NARCIS (Netherlands)

    Ruiter, A.J.H. de; Veenhuis, M.; Wendelaar Bonga, S.E.

    1988-01-01

    The occurrence of microbodies in the epithelial cells of the intestine and gallbladder of the stickleback, Gasterosteus aculeatus L., is described. In the intestine the organelles are predominantly located in the apical and perinuclear zone of the cells and may contain small crystalline cores. In ga

  3. Fermented soya bean (tempe) extracts reduce adhesion of enterotoxigenic Escherichia coli to intestinal epithelial cells

    NARCIS (Netherlands)

    Roubos-van den Hil, P.J.; Nout, M.J.R.; Beumer, R.R.; Meulen, van der J.; Zwietering, M.H.

    2009-01-01

    Aims: This study aimed to investigate the effect of processed soya bean, during the successive stages of tempe fermentation and different fermentation times, on adhesion of enterotoxigenic Escherichia coli (ETEC) K88 to intestinal brush border cells as well as Caco-2 intestinal epithelial cells; and

  4. Hydrolysed inulin alleviates the azoxymethane-induced preneoplastic aberrant crypt foci by altering selected intestinal microbiota in Sprague-Dawley rats.

    Science.gov (United States)

    Pattananandecha, Thanawat; Sirilun, Sasithorn; Duangjitcharoen, Yodsawee; Sivamaruthi, Bhagavathi Sundaram; Suwannalert, Prasit; Peerajan, Sartjin; Chaiyasut, Chaiyavat

    2016-09-01

    Context Inulin, a non-digestible carbohydrate isolated from Helianthus tuberosus L. (Asteraceae), has been shown to alter the gut beneficial bacteria including Lactobacillus spp. and Bifidobacteria. Inulin also influences the activities of intestinal microbiota that could prevent the colon cancer development. Objective This study determines the effect of hydrolysed inulin with different degrees of polymerisation on alteration of intestinal microbiota and their activities on azoxymethane (AOM)-induced preneoplastic aberrant crypt foci (ACF) in rats. Materials and methods Seventy-two male Sprague-Dawley rats were randomly divided into six groups (three control and three AOM-treated groups) and the animal were fed with either a normal diet or diet containing 10% of long-chain inulin (InuL) or short-chain inulin (InuS), respectively, for 17 weeks. Colon cancer was induced in rats by injecting AOM subcutaneously at the 8th and 9th week of the study period. At the end of the experiment, cecal contents of rats were examined for selected microbiota, organic acids, putrefactive compounds and microbial enzymes. ACF formation was microscopically examined. Results The inulin diets significantly increased the weight and decreased the pH of the caecal content. The rats fed with InuL-supplemented diet showed approximately 2.9- and 6.8-fold increases in the biomass of Lactobacillus spp. and Bifidobacteria, respectively. Naive and AOM-treated rats fed with inulin-supplemented diet showed ∼1.3- and ∼2.2-fold decreases in the biomass of Escherichia coli and Salmonella enterica serovar Typhi, respectively. Inulins significantly decreased the colonic concentration of phenol, p-cresol and indole. Reduction in the activity of microbial enzymes such as β-glucuronidase, azoreductase and nitroreductase were observed in inulin-treated animals. Reduction in the ACF formation has been observed in inulin-treated groups. Discussion and conclusion The present study demonstrates that dietary

  5. A mouse model of pathological small intestinal epithelial cell apoptosis and shedding induced by systemic administration of lipopolysaccharide

    Directory of Open Access Journals (Sweden)

    Jonathan M. Williams

    2013-11-01

    The gut barrier, composed of a single layer of intestinal epithelial cells (IECs held together by tight junctions, prevents the entrance of harmful microorganisms, antigens and toxins from the gut lumen into the blood. Small intestinal homeostasis is normally maintained by the rate of shedding of senescent enterocytes from the villus tip exactly matching the rate of generation of new cells in the crypt. However, in various localized and systemic inflammatory conditions, intestinal homeostasis can be disturbed as a result of increased IEC shedding. Such pathological IEC shedding can cause transient gaps to develop in the epithelial barrier and result in increased intestinal permeability. Although pathological IEC shedding has been implicated in the pathogenesis of conditions such as inflammatory bowel disease, our understanding of the underlying mechanisms remains limited. We have therefore developed a murine model to study this phenomenon, because IEC shedding in this species is morphologically analogous to humans. IEC shedding was induced by systemic lipopolysaccharide (LPS administration in wild-type C57BL/6 mice, and in mice deficient in TNF-receptor 1 (Tnfr1−/−, Tnfr2 (Tnfr2−/−, nuclear factor kappa B1 (Nfκb1−/− or Nfĸb2 (Nfĸb2−/−. Apoptosis and cell shedding was quantified using immunohistochemistry for active caspase-3, and gut-to-circulation permeability was assessed by measuring plasma fluorescence following fluorescein-isothiocyanate–dextran gavage. LPS, at doses ≥0.125 mg/kg body weight, induced rapid villus IEC apoptosis, with peak cell shedding occurring at 1.5 hours after treatment. This coincided with significant villus shortening, fluid exudation into the gut lumen and diarrhea. A significant increase in gut-to-circulation permeability was observed at 5 hours. TNFR1 was essential for LPS-induced IEC apoptosis and shedding, and the fate of the IECs was also dependent on NFκB, with signaling via NFκB1 favoring cell survival and

  6. Proteolytic Regulation of the Intestinal Epithelial Barrier: Mechanisms and Interventions

    Science.gov (United States)

    2014-09-01

    Studies are planned to investigate T84 restitution in the absence and presence of IL-13 in the presence or absence of matriptase. To achieve this, we...position recorded relative to the base of the crypt. We plan to investigate other cell markers and in situ cell death by TUNEL assay and activated...promoter in both heterozygous and hypomorphic St14 mice. It was planned to focus on this task in Years 2 and 3 as proposed in the timeline. The

  7. Porcine milk-derived exosomes promote proliferation of intestinal epithelial cells

    Science.gov (United States)

    Chen, Ting; Xie, Mei-Ying; Sun, Jia-Jie; Ye, Rui-Song; Cheng, Xiao; Sun, Rui-Ping; Wei, Li-Min; Li, Meng; Lin, De-Lin; Jiang, Qing-Yan; Xi, Qian-Yun; Zhang, Yong-Liang

    2016-01-01

    Milk-derived exosomes were identified as a novel mechanism of mother-to-child transmission of regulatory molecules, but their functions in intestinal tissues of neonates are not well-studied. Here, we characterized potential roles of porcine milk-derived exosomes in the intestinal tract. In vitro, treatment with milk-derived exosomes (27 ± 3 ng and 55 ± 5 ng total RNA) significantly promoted IPEC-J2 cell proliferation by MTT, CCK8, EdU fluorescence and EdU flow cytometry assays. The qRT-PCR and Western blot analyses indicated milk-derived exosomes (0.27 ± 0.03 μg total RNA) significantly promoted expression of CDX2, IGF-1R and PCNA, and inhibited p53 gene expression involved in intestinal proliferation. Additionally, six detected miRNAs were significantly increased in IPEC-J2 cell, while FAS and SERPINE were significantly down-regulated relative to that in control. In vivo, treated groups (0.125 μg and 0.25 μg total RNA) significantly raised mice’ villus height, crypt depth and ratio of villus length to crypt depth of intestinal tissues, significantly increased CDX2, PCNA and IGF-1R’ expression and significantly inhibited p53′ expression. Our study demonstrated that milk-derived exosomes can facilitate intestinal cell proliferation and intestinal tract development, thus giving a new insight for milk nutrition and newborn development and health. PMID:27646050

  8. Activation of the Epithelial-to-Mesenchymal Transition Factor Snail Mediated Acetaldehyde-Induced Intestinal Epithelial Barrier Disruption

    NARCIS (Netherlands)

    Elamin, E.; Masclee, A.; Troost, F.; Dekker, J.; Jonkers, D.

    2014-01-01

    Background : Acetaldehyde (AcH) is mutagenic and can reach high concentrations in colonic lumen after ethanol consumption and is associated with intestinal barrier dysfunction and an increased risk of progressive cancers, including colorectal carcinoma. Snail, the transcription factor of epithelial-

  9. Cyclin-dependent kinases regulate apoptosis of intestinal epithelial cells.

    Science.gov (United States)

    Bhattacharya, Sujoy; Ray, Ramesh M; Johnson, Leonard R

    2014-03-01

    Homeostasis of the gastrointestinal epithelium is dependent upon a balance between cell proliferation and apoptosis. Cyclin-dependent kinases (Cdks) are well known for their role in cell proliferation. Previous studies from our group have shown that polyamine-depletion of intestinal epithelial cells (IEC-6) decreases cyclin-dependent kinase 2 (Cdk2) activity, increases p53 and p21Cip1 protein levels, induces G1 arrest, and protects cells from camptothecin (CPT)-induced apoptosis. Although emerging evidence suggests that members of the Cdk family are involved in the regulation of apoptosis, their roles directing apoptosis of IEC-6 cells are not known. In this study, we report that inhibition of Cdk1, 2, and 9 (with the broad range Cdk inhibitor, AZD5438) in proliferating IEC-6 cells triggered DNA damage, activated p53 signaling, inhibited proliferation, and induced apoptosis. By contrast, inhibition of Cdk2 (with NU6140) increased p53 protein and activity, inhibited proliferation, but had no effect on apoptosis. Notably, AZD5438 sensitized, whereas, NU6140 rescued proliferating IEC-6 cells from CPT-induced apoptosis. However, in colon carcinoma (Caco-2) cells with mutant p53, treatment with either AZD5438 or NU6140 blocked proliferation, albeit more robustly with AZD5438. Both Cdk inhibitors induced apoptosis in Caco-2 cells in a p53-independent manner. In serum starved quiescent IEC-6 cells, both AZD5438 and NU6140 decreased TNF-α/CPT-induced activation of p53 and, consequently, rescued cells from apoptosis, indicating that sustained Cdk activity is required for apoptosis of quiescent cells. Furthermore, AZD5438 partially reversed the protective effect of polyamine depletion whereas NU6140 had no effect. Together, these results demonstrate that Cdks possess opposing roles in the control of apoptosis in quiescent and proliferating cells. In addition, Cdk inhibitors uncouple proliferation from apoptosis in a p53-dependent manner.

  10. Immunopathology of childhood celiac disease-Key role of intestinal epithelial cells.

    Science.gov (United States)

    Pietz, Grzegorz; De, Rituparna; Hedberg, Maria; Sjöberg, Veronika; Sandström, Olof; Hernell, Olle; Hammarström, Sten; Hammarström, Marie-Louise

    2017-01-01

    Celiac disease is a chronic inflammatory disease of the small intestine mucosa due to permanent intolerance to dietary gluten. The aim was to elucidate the role of small intestinal epithelial cells in the immunopathology of celiac disease in particular the influence of celiac disease-associated bacteria. Duodenal biopsies were collected from children with active celiac disease, treated celiac disease, and clinical controls. Intestinal epithelial cells were purified and analyzed for gene expression changes at the mRNA and protein levels. Two in vitro models for human intestinal epithelium, small intestinal enteroids and polarized tight monolayers, were utilized to assess how interferon-γ, interleukin-17A, celiac disease-associated bacteria and gluten influence intestinal epithelial cells. More than 25 defense-related genes, including IRF1, SPINK4, ITLN1, OAS2, CIITA, HLA-DMB, HLA-DOB, PSMB9, TAP1, BTN3A1, and CX3CL1, were significantly upregulated in intestinal epithelial cells at active celiac disease. Of these genes, 70% were upregulated by interferon-γ via the IRF1 pathway. Most interestingly, IRF1 was also upregulated by celiac disease-associated bacteria. The NLRP6/8 inflammasome yielding CASP1 and biologically active interleukin-18, which induces interferon-γ in intraepithelial lymphocytes, was expressed in intestinal epithelial cells. A key factor in the epithelial reaction in celiac disease appears to be over-expression of IRF1 that could be inherent and/or due to presence of undesirable microbes that act directly on IRF1. Dual activation of IRF1 and IRF1-regulated genes, both directly and via the interleukin-18 dependent inflammasome would drastically enhance the inflammatory response and lead to the pathological situation seen in active celiac disease.

  11. Critical role of intestinal epithelial cell-derived IL-25 in enteric nematode infection-induced changes in intestinal function

    Science.gov (United States)

    The current study investigated the mechanism of immune regulation of IL-25 and the contribution of IL-25 to nematode infection-induced alterations in intestinal smooth muscle and epithelial cell function. Mice were infected with an enteric nematode or injected with IL-25 or IL-13. In vitro smooth m...

  12. A hypermorphic epithelial β-catenin mutation facilitates intestinal tumorigenesis in mice in response to compounding WNT-pathway mutations

    Directory of Open Access Journals (Sweden)

    Michael Buchert

    2015-11-01

    Full Text Available Activation of the Wnt/β-catenin pathway occurs in the vast majority of colorectal cancers. However, the outcome of the disease varies markedly from individual to individual, even within the same tumor stage. This heterogeneity is governed to a great extent by the genetic make-up of individual tumors and the combination of oncogenic mutations. In order to express throughout the intestinal epithelium a degradation-resistant β-catenin (Ctnnb1, which lacks the first 131 amino acids, we inserted an epitope-tagged ΔN(1-131-β-catenin-encoding cDNA as a knock-in transgene into the endogenous gpA33 gene locus in mice. The resulting gpA33ΔN-Bcat mice showed an increase in the constitutive Wnt/β-catenin pathway activation that shifts the cell fate towards the Paneth cell lineage in pre-malignant intestinal epithelium. Furthermore, 19% of all heterozygous and 37% of all homozygous gpA33ΔN-Bcat mice spontaneously developed aberrant crypt foci and adenomatous polyps, at frequencies and latencies akin to those observed in sporadic colon cancer in humans. Consistent with this, the Wnt target genes, MMP7  and Tenascin-C, which are most highly expressed in benign human adenomas and early tumor stages, were upregulated in pre-malignant tissue of gpA33ΔN-Bcat mice, but those Wnt target genes associated with excessive proliferation (i.e. Cdnn1, myc were not. We also detected diminished expression of membrane-associated α-catenin and increased intestinal permeability in gpA33ΔN-Bcat mice in challenge conditions, providing a potential explanation for the observed mild chronic intestinal inflammation and increased susceptibility to azoxymethane and mutant Apc-dependent tumorigenesis. Collectively, our data indicate that epithelial expression of ΔN(1-131-β-catenin in the intestine creates an inflammatory microenvironment and co-operates with other mutations in the Wnt/β-catenin pathway to facilitate and promote tumorigenesis.

  13. WNT signaling controls expression of pro-apoptotic BOK and BAX in intestinal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Zeilstra, Jurrit; Joosten, Sander P.J. [Department of Pathology, Academic Medical Center, University of Amsterdam (Netherlands); Wensveen, Felix M. [Department of Experimental Immunology, Academic Medical Center, Amsterdam (Netherlands); Dessing, Mark C.; Schuetze, Denise M. [Department of Pathology, Academic Medical Center, University of Amsterdam (Netherlands); Eldering, Eric [Department of Experimental Immunology, Academic Medical Center, Amsterdam (Netherlands); Spaargaren, Marcel [Department of Pathology, Academic Medical Center, University of Amsterdam (Netherlands); Pals, Steven T., E-mail: s.t.pals@amc.uva.nl [Department of Pathology, Academic Medical Center, University of Amsterdam (Netherlands)

    2011-03-04

    Research highlights: {yields} Intestinal adenomas initiated by aberrant activation of the WNT pathway displayed an increased sensitivity to apoptosis. {yields} Expression profiling of apoptosis-related genes in Apc{sup Min/+} mice revealed the differential expression of pro-apoptotic Bok and Bax. {yields} APC-mutant adenomatous crypts in FAP patients showed strongly increased BAX immunoreactivity. {yields} Blocking of {beta}-catenin/TCF-4-mediated signaling in colon cancer cells reduced the expression of BOK and BAX. -- Abstract: In a majority of cases, colorectal cancer is initiated by aberrant activation of the WNT signaling pathway. Mutation of the genes encoding the WNT signaling components adenomatous polyposis coli or {beta}-catenin causes constitutively active {beta}-catenin/TCF-mediated transcription, driving the transformation of intestinal crypts to cancer precursor lesions, called dysplastic aberrant crypt foci. Deregulated apoptosis is a hallmark of adenomatous colon tissue. However, the contribution of WNT signaling to this process is not fully understood. We addressed this role by analyzing the rate of epithelial apoptosis in aberrant crypts and adenomas of the Apc{sup Min/+} mouse model. In comparison with normal crypts and adenomas, aberrant crypts displayed a dramatically increased rate of apoptotic cell death. Expression profiling of apoptosis-related genes along the crypt-villus axis and in Apc mutant adenomas revealed increased expression of two pro-apoptotic Bcl-2 family members in intestinal adenomas, Bok and Bax. Analysis of the colon of familial adenomatous polyposis (FAP) patients along the crypt-to-surface axis, and of dysplastic crypts, corroborated this expression pattern. Disruption of {beta}-catenin/TCF-4-mediated signaling in the colorectal cancer cell line Ls174T significantly decreased BOK and BAX expression, confirming WNT-dependent regulation in intestinal epithelial cells. Our results suggest a feedback mechanism by which

  14. Modelling the dynamics of stem cells in colonic crypts

    Science.gov (United States)

    Sirio, Orozco-Fuentes; Barrio, Rafael A.

    2017-02-01

    We present a theoretical and computational framework to model the colonic crypt organisation in the human intestine. We construct a theoretical and computational framework to model the colonic crypt behaviour, using a Voronoi tessellation to represent each cell and elastic forces between them we addressed how their dynamical disfunction can lead to tumour masses and cancer. Our results indicate that for certain parameters the crypt is in a homeostatic state, but slight changes on their values can disrupt this behaviour.

  15. Inflammation and the Intestinal Barrier: Leukocyte–Epithelial Cell Interactions, Cell Junction Remodeling, and Mucosal Repair

    Science.gov (United States)

    Luissint, Anny-Claude; Parkos, Charles A.; Nusrat, Asma

    2017-01-01

    The intestinal tract is lined by a single layer of columnar epithelial cells that forms a dynamic, permeable barrier allowing for selective absorption of nutrients, while restricting access to pathogens and food-borne antigens. Precise regulation of epithelial barrier function is therefore required for maintaining mucosal homeostasis and depends, in part, on barrier-forming elements within the epithelium and a balance between pro- and anti-inflammatory factors in the mucosa. Pathologic states, such as inflammatory bowel disease, are associated with a leaky epithelial barrier, resulting in excessive exposure to microbial antigens, recruitment of leukocytes, release of soluble mediators, and ultimately mucosal damage. An inflammatory microenvironment affects epithelial barrier properties and mucosal homeostasis by altering the structure and function of epithelial intercellular junctions through direct and indirect mechanisms. We review our current understanding of complex interactions between the intestinal epithelium and immune cells, with a focus on pathologic mucosal inflammation and mechanisms of epithelial repair. We discuss leukocyte–epithelial interactions, as well as inflammatory mediators that affect the epithelial barrier and mucosal repair. Increased knowledge of communication networks between the epithelium and immune system will lead to tissue-specific strategies for treating pathologic intestinal inflammation. PMID:27436072

  16. Vectorial secretion of interleukin-8 mediates autocrine signalling in intestinal epithelial cells via apically located CXCR1

    NARCIS (Netherlands)

    Rossi, Oriana; Karczewski, Jurgen; Stolte, Ellen H; Brummer, Robert J M; van Nieuwenhoven, Michiel A; Meijerink, Marjolein; van Neerven, Joost R J; van Ijzendoorn, Sven C D; van Baarlen, Peter; Wells, Jerry M

    2013-01-01

    BACKGROUND: In the intestinal mucosa, several adaptations of TLR signalling have evolved to avoid chronic inflammatory responses to the presence of commensal microbes. Here we investigated whether polarized monolayers of intestinal epithelial cells might regulate inflammatory responses by secreting

  17. Mapping of HNF4alpha target genes in intestinal epithelial cells

    DEFF Research Database (Denmark)

    Boyd, Mette; Bressendorff, Simon; Moller, Jette

    2009-01-01

    in the human intestinal epithelial cells in order to elucidate the role of HNF4alpha in the intestinal differentiation progress. METHODS: We have performed a ChIP-chip analysis of the human intestinal cell line Caco-2 in order to make a genome-wide identification of HNF4alpha binding to promoter regions......ABSTRACT: BACKGROUND: The role of HNF4alpha has been extensively studied in hepatocytes and pancreatic beta-cells, and HNF4alpha is also regarded as key regulator of intestinal epithelial cell differentiation as well. The aim of the present work is to identify novel HNF4alpha target genes......), and the tight junction protein cingulin (CGN) promoters verified that these genes are bound by HNF4alpha in Caco2 cells and for the Cdx-2 and trehalase promoters the HNF4alpha binding was verified in mouse small intestine epithelium. CONCLUSION: The HNF4alpha regulation of the Cdx-2 promoter unravels...

  18. A Comparative Study on Rat Intestinal Epithelial Cells and Resident Gut Bacteria (ii) Effect of Arsenite

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In order to use facultative gut bacteria as an alternate to animals for the initial gastrointestinal toxicity screening of heavy metals, a comparative study on rat intestinal epithelial cells and resident gut bacteria was undertaken.Methods in vitro growth rate of four gut bacteria, dehydrogenase (DHA) and esterase (EA) activity test, intestinal epithelial and bacterial cell membrane enzymes and in situ effect of arsenite were analysed. Results Growth profile of mixed resident population of gut bacteria and pure isolates of Escherichia coli, Pseudomonas sp., Lactobacillus sp., and Staphylococcus sp.revealed an arsenite (2-20 ppm) concentration-dependent inhibition. The viability pattern of epithelial cells also showed similar changes. DHA and EA tests revealed significant inhibition (40%-72%) with arsenite exposure of 5 and 10 ppm in isolated gut bacteria and epithelial cells. Decrease in membrane alkaline phosphatase and Ca2+-Mg2+-ATPase activities was in the range of 33%-55% in four bacteria at the arsenite exposure of 10 ppm, whereas it was 60%-65% in intestinal epithelial villus cells. in situ incubation of arsenite using intestinal loops also showed more or less similar changes in membrane enzymes of resident gut bacterial population and epithelial cells. Conclusion The results indicate that facultative gut bacteria can be used as suitable in vitro model for the preliminary screening of arsenical gastrointestinal cytotoxic effects.

  19. Effects of propofol on damage of rat intestinal epithelial cells induced by heat stress and lipopolysaccharides

    Energy Technology Data Exchange (ETDEWEB)

    Tang, J.; Jiang, Y. [Southern Medical University, Nanfang Hospital, Department of Anesthesia, Guangzhou, China, Department of Anesthesia, Nanfang Hospital, Southern Medical University, Guangzhou (China); Tang, Y.; Chen, B. [Guangzhou General Hospital of Guangzhou Military Command, Department of Intensive Care Unit, Guangzhou, China, Department of Intensive Care Unit, Guangzhou General Hospital of Guangzhou Military Command, Guangzhou (China); Sun, X. [Laboratory of Traditional Chinese Medicine Syndrome, School of Traditional Chinese Medicine, Southern Medical University, Guangzhou (China); Su, L.; Liu, Z. [Guangzhou General Hospital of Guangzhou Military Command, Department of Intensive Care Unit, Guangzhou, China, Department of Intensive Care Unit, Guangzhou General Hospital of Guangzhou Military Command, Guangzhou (China)

    2013-06-25

    Gut-derived endotoxin and pathogenic bacteria have been proposed as important causative factors of morbidity and death during heat stroke. However, it is still unclear what kind of damage is induced by heat stress. In this study, the rat intestinal epithelial cell line (IEC-6) was treated with heat stress or a combination of heat stress and lipopolysaccharide (LPS). In addition, propofol, which plays an important role in anti-inflammation and organ protection, was applied to study its effects on cellular viability and apoptosis. Heat stress, LPS, or heat stress combined with LPS stimulation can all cause intestinal epithelial cell damage, including early apoptosis and subsequent necrosis. However, propofol can alleviate injuries caused by heat stress, LPS, or the combination of heat stress and LPS. Interestingly, propofol can only mitigate LPS-induced intestinal epithelial cell apoptosis, and has no protective role in heat-stress-induced apoptosis. This study developed a model that can mimic the intestinal heat stress environment. It demonstrates the effects on intestinal epithelial cell damage, and indicated that propofol could be used as a therapeutic drug for the treatment of heat-stress-induced intestinal injuries.

  20. Effects of propofol on damage of rat intestinal epithelial cells induced by heat stress and lipopolysaccharides

    Directory of Open Access Journals (Sweden)

    J. Tang

    2013-06-01

    Full Text Available Gut-derived endotoxin and pathogenic bacteria have been proposed as important causative factors of morbidity and death during heat stroke. However, it is still unclear what kind of damage is induced by heat stress. In this study, the rat intestinal epithelial cell line (IEC-6 was treated with heat stress or a combination of heat stress and lipopolysaccharide (LPS. In addition, propofol, which plays an important role in anti-inflammation and organ protection, was applied to study its effects on cellular viability and apoptosis. Heat stress, LPS, or heat stress combined with LPS stimulation can all cause intestinal epithelial cell damage, including early apoptosis and subsequent necrosis. However, propofol can alleviate injuries caused by heat stress, LPS, or the combination of heat stress and LPS. Interestingly, propofol can only mitigate LPS-induced intestinal epithelial cell apoptosis, and has no protective role in heat-stress-induced apoptosis. This study developed a model that can mimic the intestinal heat stress environment. It demonstrates the effects on intestinal epithelial cell damage, and indicated that propofol could be used as a therapeutic drug for the treatment of heat-stress-induced intestinal injuries.

  1. Effects of propofol on damage of rat intestinal epithelial cells induced by heat stress and lipopolysaccharides

    Directory of Open Access Journals (Sweden)

    J. Tang

    Full Text Available Gut-derived endotoxin and pathogenic bacteria have been proposed as important causative factors of morbidity and death during heat stroke. However, it is still unclear what kind of damage is induced by heat stress. In this study, the rat intestinal epithelial cell line (IEC-6 was treated with heat stress or a combination of heat stress and lipopolysaccharide (LPS. In addition, propofol, which plays an important role in anti-inflammation and organ protection, was applied to study its effects on cellular viability and apoptosis. Heat stress, LPS, or heat stress combined with LPS stimulation can all cause intestinal epithelial cell damage, including early apoptosis and subsequent necrosis. However, propofol can alleviate injuries caused by heat stress, LPS, or the combination of heat stress and LPS. Interestingly, propofol can only mitigate LPS-induced intestinal epithelial cell apoptosis, and has no protective role in heat-stress-induced apoptosis. This study developed a model that can mimic the intestinal heat stress environment. It demonstrates the effects on intestinal epithelial cell damage, and indicated that propofol could be used as a therapeutic drug for the treatment of heat-stress-induced intestinal injuries.

  2. Growth factor TGF-β induces intestinal epithelial cell (IEC-6) differentiation: miR-146b as a regulatory component in the negative feedback loop.

    Science.gov (United States)

    Liao, Yalin; Zhang, Man; Lönnerdal, Bo

    2013-01-01

    TGF-β is a potent pleiotropic factor that promotes small intestinal cell differentiation. The role of microRNAs in the TGF-β induction of intestinal epithelial phenotype is largely unknown. We hypothesized that microRNAs are functionally involved in TGF-β-induced intestinal cell growth. In this study, TGF-β caused a morphological change of IEC-6 cells and stimulated expression of the epithelial cell markers alkaline phosphatase, villin, and aminopeptidase N. By global microRNA profiling during TGF-β-induced intestinal crypt cell (IEC-6) differentiation, we identified 19 differentially expressed microRNAs. We showed by real-time Q-PCR that miR-146b expression increased rapidly after TGF-β treatment; sequence analysis and in vitro assays revealed that miR-146b targets SIAH2, an E3 ubiquitin ligase, with decreased protein expression upon IEC-6 cell differentiation. Transfection of miR-146b inhibitor before TGF-β treatment blocked the down-regulation of SIAH2 in response to TGF-β. Moreover, SIAH2 over-expression during TGF-β treatment caused a significant decrease in Smad7 protein expression in IEC-6 cells. Furthermore, activation of the ERK1/2 pathway is active in the up-regulation of miR-146b by TGF-β. These findings suggest a novel mechanism whereby TGF-β signaling during IEC-6 cell differentiation may be modulated in part by microRNAs, and we propose a key role for miR-146b in the homeostasis of growth factor TGF-β signaling through a negative feedback regulation involving down-regulation of SIAH2 repressed Smad7 activities.

  3. The role of ER stress response on ionizing radiation-induced apoptosis in intestinal epithelial cells

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    Lee, Eun Sang; Kim, Kwang Seok; Woo, Sang Keun; Lee, Yong Jin; Jeong, Jae Hoon; Lee, Yoon Jin; Kang, Seong Man; Lim, Young Bin [Laboratory of Radiation Effect, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

    2014-04-15

    Apoptosis in the intestinal epithelium is the primary pathologic factor that initiates radiation-induced intestinal injury. However, mechanism involved in ionizing radiation (IR)-induced apoptosis in the intestinal epithelium is not clearly understood. The endoplasmic reticulum (ER) stress is triggered by perturbation of the ER functions, leading to the activation of the unfolded protein response (UPR), an adaptive signaling cascade aimed at restoring ER homeostasis by facilitating the degradation of misfolded proteins and expanding the protein folding capacity of the cell. Recently, IR has also been shown to induce ER stress, thereby activating the UPR signaling pathway in intestinal epithelial cells. In this study, we report the role of ER stress responses in IR-induced intestinal epithelial cell death. We show that chemical ER stress inducers, such as tunicamycin or thapsigargin, enhance IR-induced caspase3 activation. Knockdown of xbp1 or atf6 with siRNA leads to inhibition of IR-induced caspase3 activation. Taken together, our results suggest a pro-apoptotic role of ER stress in IR-exposed intestinal epithelial cells. Our findings could contribute to the development of new strategies based on modulating ER stress responses to prevent IR-induced intestinal injury.

  4. Improving access to intestinal stem cells as a step toward intestinal gene transfer.

    Science.gov (United States)

    Sandberg, J W; Lau, C; Jacomino, M; Finegold, M; Henning, S J

    1994-03-01

    In previous studies exploring the intestinal epithelium as a potential site for somatic gene therapy, we concluded that the mucus lining the intestine constitutes a significant barrier to any attempts at gene transfer via the lumenal route. The mucus problem is aggravated by the fact that the epithelial stem cells, which are the logical target for gene transfer, are located deep in the intestinal crypts. The goals of the current study were to develop procedures that would improve accessibility to the intestinal stem cells and which would effect in vivo mucus removal without damaging the underlying epithelium. Initial experiments involved evaluation of the use of distension to improve accessibility to the intestinal crypts and the use of the mucolytic agents dithiothreitol (DTT) and N-acetyl-cysteine (NAC) versus a control solution of phosphate-buffered saline (PBS) for mucus removal. Catheters were inserted in each end of 3-cm terminal ileal segments in anesthetized rats. Two milliliters of agent was instilled into the clamped segment for 2 min, removed, and repeated. Lumenal distension resulted in shortened villi with wider intervillus spacing, thereby improving crypt access. Both NAC and DTT washes removed significant mucus between the villi but failed to reach the crypt lumen. To enhance mucus release from the crypt lumen, pilocarpine was selected due to its cholinergic properties and preferential binding to muscarinic receptors on crypt goblet cells. Pilocarpine given intraperitoneally 30 min prior to the mucolytic or PBS wash resulted in significant eradication of mucus down into the crypt lumen. This effect was still evident 3-4 hr later provided the intestine remained undisturbed.

  5. Role of chemokine receptors and intestinal epithelial cells in the mucosal inflammation and tolerance.

    Science.gov (United States)

    Kulkarni, Neeraja; Pathak, Manisha; Lal, Girdhari

    2017-02-01

    The intestinal epithelial lining is a very dynamic interface, where multiple interactions occur with the external world. The intestinal epithelial barrier is continuously exposed to a huge load of commensal microorganisms, food-borne antigens, as well as invading enteropathogens. Intestinal epithelial cells (IECs) and underlying immune cells are the main players in maintaining the delicate balance between gut tolerance and inflammation. IECs deferentially express the variety of chemokines and chemokine receptors, and these receptor-ligand interactions not only mediate the infiltration and activation of immune cells but also switch on the survival cascades in IECs. In this review, we discussed how chemokine-chemokine receptor-induced interactions play a central role to coordinate the interplay between IECs and gut immune cells to maintain homeostasis or elicit gut inflammation. Furthermore, we discussed how chemokines and chemokine receptors were used as a target for developing new drugs and therapies to control gut inflammation and autoimmunity. © Society for Leukocyte Biology.

  6. The jagged-2/notch-1/hes-1 pathway is involved in intestinal epithelium regeneration after intestinal ischemia-reperfusion injury.

    Directory of Open Access Journals (Sweden)

    Guoqing Chen

    Full Text Available BACKGROUND: Notch signaling plays a critical role in the maintenance of intestinal crypt epithelial cell proliferation. The aim of this study was to investigate the role of Notch signaling in the proliferation and regeneration of intestinal epithelium after intestinal ischemia reperfusion (I/R injury. METHODS: Male Sprague-Dawley rats were subjected to sham operation or I/R by occlusion of the superior mesenteric artery (SMA for 20 min. Intestinal tissue samples were collected at 0, 1, 2, 4, and 6 h after reperfusion. Proliferation of the intestinal epithelium was evaluated by immunohistochemical staining of proliferating nuclear antigen (PCNA. The mRNA and protein expression levels of Notch signaling components were examined using Real-time PCR and Western blot analyses. Immunofluorescence was also performed to detect the expression and location of Jagged-2, cleaved Notch-1, and Hes-1 in the intestine. Finally, the γ-secretase inhibitor DAPT and the siRNA for Jagged-2 and Hes-1 were applied to investigate the functional role of Notch signaling in the proliferation of intestinal epithelial cells in an in vitro IEC-6 culture system. RESULTS: I/R injury caused increased intestinal crypt epithelial cell proliferation and increased mRNA and protein expression of Jagged-2, Notch-1, and Hes-1. The immunofluorescence results further confirmed increased protein expression of Jagged-2, cleaved Notch-1, and Hes-1 in the intestinal crypts. The inhibition of Notch signaling with DAPT and the suppression of Jagged-2 and Hes-1 expression using siRNA both significantly inhibited the proliferation of IEC-6 cells. CONCLUSION: The Jagged-2/Notch-1/Hes-1 signaling pathway is involved in intestinal epithelium regeneration early after I/R injury by increasing crypt epithelial cell proliferation.

  7. Internalization-dependent recognition of Mycobacterium avium ssp. paratuberculosis by intestinal epithelial cells.

    Science.gov (United States)

    Pott, Johanna; Basler, Tina; Duerr, Claudia U; Rohde, Manfred; Goethe, Ralph; Hornef, Mathias W

    2009-12-01

    Mycobacterium avium ssp. paratuberculosis (MAP) is the causative agent of Johne's disease, a highly prevalent chronic intestinal infection in domestic and wildlife ruminants. The microbial pathogenesis of MAP infection has attracted additional attention due to an association with the human enteric inflammatory Crohn's disease. MAP is acquired by the faecal-oral route prompting us to study the interaction with differentiated intestinal epithelial cells. MAP was rapidly internalized and accumulated in a late endosomal compartment. In contrast to other opportunistic mycobacteria or M. bovis, MAP induced significant epithelial activation as indicated by a NF-kappaB-independent but Erk-dependent chemokine secretion. Surprisingly, MAP-induced chemokine production was completely internalization-dependent as inhibition of Rac-dependent bacterial uptake abolished epithelial activation. In accordance, innate immune recognition of MAP by differentiated intestinal epithelial cells occurred through the intracellularly localized pattern recognition receptors toll-like receptor 9 and NOD1 with signal transduction via the adaptor molecules MyD88 and RIP2. The internalization-dependent innate immune activation of intestinal epithelial cells is in contrast to the stimulation of professional phagocytes by extracellular bacterial constituents and might significantly contribute to the histopathological changes observed during enteric MAP infection.

  8. STAT3 links IL-22 signaling in intestinal epithelial cells to mucosal wound healing.

    Science.gov (United States)

    Pickert, Geethanjali; Neufert, Clemens; Leppkes, Moritz; Zheng, Yan; Wittkopf, Nadine; Warntjen, Moritz; Lehr, Hans-Anton; Hirth, Sebastian; Weigmann, Benno; Wirtz, Stefan; Ouyang, Wenjun; Neurath, Markus F; Becker, Christoph

    2009-07-06

    Signal transducer and activator of transcription (STAT) 3 is a pleiotropic transcription factor with important functions in cytokine signaling in a variety of tissues. However, the role of STAT3 in the intestinal epithelium is not well understood. We demonstrate that development of colonic inflammation is associated with the induction of STAT3 activity in intestinal epithelial cells (IECs). Studies in genetically engineered mice showed that epithelial STAT3 activation in dextran sodium sulfate colitis is dependent on interleukin (IL)-22 rather than IL-6. IL-22 was secreted by colonic CD11c(+) cells in response to Toll-like receptor stimulation. Conditional knockout mice with an IEC-specific deletion of STAT3 activity were highly susceptible to experimental colitis, indicating that epithelial STAT3 regulates gut homeostasis. STAT3(IEC-KO) mice, upon induction of colitis, showed a striking defect of epithelial restitution. Gene chip analysis indicated that STAT3 regulates the cellular stress response, apoptosis, and pathways associated with wound healing in IECs. Consistently, both IL-22 and epithelial STAT3 were found to be important in wound-healing experiments in vivo. In summary, our data suggest that intestinal epithelial STAT3 activation regulates immune homeostasis in the gut by promoting IL-22-dependent mucosal wound healing.

  9. Effect of Ozone on Intestinal Epithelial Homeostasis in a Rat Model

    Directory of Open Access Journals (Sweden)

    Igor Sukhotnik

    2015-01-01

    Full Text Available Background: The positive effects of ozone therapy have been described in many gastrointestinal disorders. The mechanisms of this positive effect of ozone therapy are poorly understood. The purpose of the present study was to investigate whether the use of ozone may potentiate the gut intestinal mucosal homeostasis in a rat model. Methods: Adult rats weighing 250–280 g were randomly assigned to one of three experimental groups of 8 rats each: 1 Control rats were given 2 mL of water by gavage and intraperitoneally (IP for 5 days; 2 O3-PO rats were treated with 2 mL of ozone/oxygen mixture by gavage and 2 mL of water IP for 5 days; 3 O3-IP rats were treated with 2 mL of water by gavage and 2 mL of ozone/oxygen mixture IP for 5 days. Rats were sacrificed on day 6. Bowel and mucosal weight, mucosal DNA and protein, villus height and crypt depth, and cell proliferation and apoptosis were evaluated following sacrifice. Results: The group of O3-IP rats demonstrated a greater jejunal and ileal villus height and crypt depth, a greater enterocyte proliferation index in jejunum, and lower enterocyte apoptosis in ileum compared to control animals. Oral administration of the ozone/oxygen mixture resulted in a less significant effect on cell turnover. Conclusions: Treatment with an ozone/oxygen mixture stimulates intestinal cell turnover in a rat model. Intraperitoneal administration of ozone resulted in a more significant intestinal trophic effect than oral administration.

  10. FAK regulates intestinal epithelial cell survival and proliferation during mucosal wound healing.

    Directory of Open Access Journals (Sweden)

    Katherine A Owen

    Full Text Available BACKGROUND: Following damage to the intestinal epithelium, restoration of epithelial barrier integrity is triggered by a robust proliferative response. In other tissues, focal adhesion kinase (FAK regulates many of the cellular processes that are critical for epithelial homeostasis and restitution, including cell migration, proliferation and survival. However, few studies to date have determined how FAK contributes to mucosal wound healing in vivo. METHODOLOGY AND PRINCIPAL FINDINGS: To examine the role of FAK in intestinal epithelial homeostasis and during injury, we generated intestinal epithelium (IE-specific conditional FAK knockout mice. Colitis was induced with dextran-sulfate-sodium (DSS and intestinal tissues were analyzed by immunohistochemistry and immunoblotting. While intestinal development occurred normally in mice lacking FAK, FAK-deficient animals were profoundly susceptible to colitis. The loss of epithelial FAK resulted in elevated p53 expression and an increased sensitivity to apoptosis, coincident with a failure to upregulate epithelial cell proliferation. FAK has been reported to function as a mechanosensor, inducing cyclin D1 expression and promoting cell cycle progression under conditions in which tissue/matrix stiffness is increased. Collagen deposition, a hallmark of inflammatory injury resulting in increased tissue rigidity, was observed in control and FAK knockout mice during colitis. Despite this fibrotic response, the colonic epithelium in FAK-deficient mice exhibited significantly reduced cyclin D1 expression, suggesting that proliferation is uncoupled from fibrosis in the absence of FAK. In support of this hypothesis, proliferation of Caco-2 cells increased proportionally with matrix stiffness in vitro only under conditions of normal FAK expression; FAK depleted cells exhibited reduced proliferation concomitant with attenuated cyclin D1 expression. CONCLUSIONS: In the colon, FAK functions as a regulator of

  11. Diet-Derived Short Chain Fatty Acids Stimulate Intestinal Epithelial Cells To Induce Mucosal Tolerogenic Dendritic Cells.

    Science.gov (United States)

    Goverse, Gera; Molenaar, Rosalie; Macia, Laurence; Tan, Jian; Erkelens, Martje N; Konijn, Tanja; Knippenberg, Marlene; Cook, Emma C L; Hanekamp, Diana; Veldhoen, Marc; Hartog, Anita; Roeselers, Guus; Mackay, Charles R; Mebius, Reina E

    2017-03-01

    The gastrointestinal tract is continuously exposed to many environmental factors that influence intestinal epithelial cells and the underlying mucosal immune system. In this article, we demonstrate that dietary fiber and short chain fatty acids (SCFAs) induced the expression of the vitamin A-converting enzyme RALDH1 in intestinal epithelial cells in vivo and in vitro, respectively. Furthermore, our data showed that the expression levels of RALDH1 in small intestinal epithelial cells correlated with the activity of vitamin A-converting enzymes in mesenteric lymph node dendritic cells, along with increased numbers of intestinal regulatory T cells and a higher production of luminal IgA. Moreover, we show that the consumption of dietary fiber can alter the composition of SCFA-producing microbiota and SCFA production in the small intestines. In conclusion, our data illustrate that dietary adjustments affect small intestinal epithelial cells and can be used to modulate the mucosal immune system.

  12. Adult intestinal stem cells: critical drivers of epithelial homeostasis and regeneration.

    Science.gov (United States)

    Barker, Nick

    2014-01-01

    Small populations of adult stem cells are responsible for the remarkable ability of the epithelial lining of the intestine to be efficiently renewed and repaired throughout life. The recent discovery of specific markers for these stem cells, together with the development of new technologies to track endogenous stem cell activity in vivo and to exploit their ability to generate new epithelia ex vivo, has greatly improved our understanding of stem cell-driven homeostasis, regeneration and cancer in the intestine. These exciting new insights into the biology of intestinal stem cells have the potential to accelerate the development of stem cell-based therapies and ameliorate cancer treatments.

  13. Trichuris suis excretory secretory products (ESP) elicit interleukin-6 (IL-6) and IL-10 secretion from intestinal epithelial cells (IPEC-1).

    Science.gov (United States)

    Parthasarathy, G; Mansfield, L S

    2005-08-10

    Immune responses to gastrointestinal helminth infections have received increasing attention due to similarities to allergen-induced responses. In fact, the whipworm parasite of swine, Trichuris suis, has been used in beginning clinical trials as an antidote to inflammatory bowel disease. This strategy was based on this similarity and the recognition that other worms have been documented to induce anti-inflammatory responses in the host. In an effort to understand the basis for this response, we hypothesized that the proteins and peptides secreted by T. suis stimulate local intestinal epithelial cells to produce anti-inflammatory cytokines. To test this hypothesis in a correlate system of the natural swine host, T. suis excretory secretory products (ESP) were used to treat both differentiated and undifferentiated intestinal pig epithelial cells (IPEC-1) in vitro as a model for the effect on villus tip and crypt epithelial cells in the vicinity of the worms. IPEC-1 were exposed to low-level doses (0.3mg/ml) of T. suis ESP, and IL-4, IL-6 and IL-10 cytokine responses were measured by an enzyme-linked immunosorbant assay (ELISA). IL-6 was the predominant cytokine produced, accompanied by moderate IL-10 secretion from both differentiated and undifferentiated cells. As expected, IL-4 was not produced by IPEC-1. Additionally, IL-6 and IL-10 cytokines were produced within 24h, suggesting that these two cytokines form part of the primary host response to T. suis infections. These data suggest that T. suis ESP could enhance host immune responses and modulation through the induction of enteric IL-6 and IL-10.

  14. Curcumin Suppresses Intestinal Fibrosis by Inhibition of PPARγ-Mediated Epithelial-Mesenchymal Transition

    Science.gov (United States)

    Jiang, Bin; Wang, Hui; Shen, Cunsi; Chen, Hao

    2017-01-01

    Intestinal fibrotic stricture is a major complication of Crohn's disease (CD) and epithelial-to-mesenchymal transition (EMT) is considered as an important contributor to the formation of intestinal fibrosis by increasing extracellular matrix (ECM) proteins. Curcumin, a compound derived from rhizomes of Curcuma, has been demonstrated with a potent antifibrotic effect. However, its effect on intestinal fibrosis and the potential mechanism is not completely understood. Here we found that curcumin pretreatment significantly represses TGF-β1-induced Smad pathway and decreases its downstream α-smooth muscle actin (α-SMA) gene expression in intestinal epithelial cells (IEC-6); in contrast, curcumin increases expression of E-cadherin and peroxisome proliferator-activated receptor γ (PPARγ) in IEC-6. Moreover, curcumin promotes nuclear translocation of PPARγ and the inhibitory effect of curcumin on EMT could be reversed by PPARγ antagonist GW9662. Consistently, in the rat model of intestinal fibrosis induced by 2,4,5-trinitrobenzene sulphonic acid (TNBS), oral curcumin attenuates intestinal fibrosis by increasing the expression of PPARγ and E-cadherin and decreasing the expression of α-SMA, FN, and CTGF in colon tissue. Collectively, these results indicated that curcumin is able to prevent EMT progress in intestinal fibrosis by PPARγ-mediated repression of TGF-β1/Smad pathway. PMID:28203261

  15. Gut microbial colonization orchestrates TLR2 expression, signaling and epithelial proliferation in the small intestinal mucosa.

    Directory of Open Access Journals (Sweden)

    Nives Hörmann

    Full Text Available The gut microbiota is an environmental factor that determines renewal of the intestinal epithelium and remodeling of the intestinal mucosa. At present, it is not resolved if components of the gut microbiota can augment innate immune sensing in the intestinal epithelium via the up-regulation of Toll-like receptors (TLRs. Here, we report that colonization of germ-free (GF Swiss Webster mice with a complex gut microbiota augments expression of TLR2. The microbiota-dependent up-regulation of components of the TLR2 signaling complex could be reversed by a 7 day broad-spectrum antibiotic treatment. TLR2 downstream signaling via the mitogen-activated protein kinase (ERK1/2 and protein-kinase B (AKT induced by bacterial TLR2 agonists resulted in increased proliferation of the small intestinal epithelial cell line MODE-K. Mice that were colonized from birth with a normal gut microbiota (conventionally-raised; CONV-R showed signs of increased small intestinal renewal and apoptosis compared with GF controls as indicated by elevated mRNA levels of the proliferation markers Ki67 and Cyclin D1, elevated transcripts of the apoptosis marker Caspase-3 and increased numbers of TUNEL-positive cells per intestinal villus structure. In accordance, TLR2-deficient mice showed reduced proliferation and reduced apoptosis. Our findings suggest that a tuned proliferation response of epithelial cells following microbial colonization could aid to protect the host from its microbial colonizers and increase intestinal surface area.

  16. A pSMAD/CDX2 Complex Is Essential for the Intestinalization of Epithelial Metaplasia

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    Luigi Mari

    2014-05-01

    Full Text Available The molecular mechanisms leading to epithelial metaplasias are poorly understood. Barrett's esophagus is a premalignant metaplastic change of the esophageal epithelium into columnar epithelium, occurring in patients suffering from gastroesophageal reflux disease. Mechanisms behind the development of the intestinal subtype, which is associated with the highest cancer risk, are unclear. In humans, it has been suggested that a nonspecialized columnar metaplasia precedes the development of intestinal metaplasia. Here, we propose that a complex made up of at least two factors needs to be activated simultaneously to drive the expression of intestinal type of genes. Using unique animal models and robust in vitro assays, we show that the nonspecialized columnar metaplasia is a precursor of intestinal metaplasia and that pSMAD/CDX2 interaction is essential for the switch toward an intestinal phenotype.

  17. Intestinal epithelial cell secretion of RELM-beta protects against gastrointestinal worm infection

    Science.gov (United States)

    IL-4 and IL-13 protect against parasitic helminths, but little is known about the mechanism of host protection. We show that IL-4/IL-13 confer immunity against worms by inducing intestinal epithelial cells (IEC) to differentiate into goblet cells that secrete resistin-like molecule beta (RELMB). R...

  18. A new in vitro model using small intestinal epithelial cells to enhance infection of Cryptosporidium parvum

    Science.gov (United States)

    To better understand and study the infection of the protozoan parasite Cryptosporidium parvum, a more sensitive in vitro assay is required. In vivo, this parasite infects the epithelial cells of the microvilli layer in the small intestine. While cell infection models using colon,...

  19. The influence of microbial metabolites on human intestinal epithelial cells and macrophages in vitro

    NARCIS (Netherlands)

    Nuenen, M.H.M.C. van; Ligt, R.A.F. de; Doornbos, R.P.; Woude, J.C.J. van der; Kuipers, E.J.; Venema, K.

    2005-01-01

    Microbial metabolites may influence the metabolic integrity of intestinal epithelial cells and induce mucosal immune responses. Therefore, we investigated the effects of the microbial metabolites butyrate, iso-valerate, and ammonium on Caco-2 cells and macrophages. Barrier functioning was determined

  20. Gut microbiota regulates NKG2D ligand expression on intestinal epithelial cells

    DEFF Research Database (Denmark)

    Hansen, Camilla Hartmann Friis; Holm, Thomas L.; Krych, Lukasz

    2013-01-01

    Intestinal epithelial cells (IECs) are one of a few cell types in the body with constitutive surface expression of natural killer group 2 member D (NKG2D) ligands, although the magnitude of ligand expression by IECs varies. Here, we investigated whether the gut microbiota regulates the NKG2D ligand...

  1. Epithelial Histone Deacetylase 3 Instructs Intestinal Immunity by Coordinating Local Lymphocyte Activation

    Directory of Open Access Journals (Sweden)

    Nazanin Navabi

    2017-05-01

    Full Text Available Mucosal tissues are constantly in direct contact with diverse beneficial and pathogenic microbes, highlighting the need for orchestrating complex microbial signals to sustain effective host defense. Here, we show an essential role for intestinal epithelial cell expression of histone deacetylase 3 (HDAC3 in responding to pathogenic microbes and activating protective innate immunity. Mice lacking HDAC3 in intestinal epithelial cells were more susceptible to Citrobacter rodentium when under tonic stimulation by the commensal microbiota. This impaired host defense reflected significantly decreased IFNγ production by intraepithelial CD8+ T cells early during infection. Further, HDAC3 was necessary for infection-induced epithelial expression of the IFNγ-inducing factor IL-18, and administration of IL-18 restored IFNγ activity to resident CD8+ T cells and reduced infection. Thus, HDAC3 mediates communication between intestinal epithelial cells and resident lymphocytes, revealing that epithelial priming by an epigenetic modifier may direct mucosal regulation of host defense against pathogenic microbes.

  2. A20 restricts wnt signaling in intestinal epithelial cells and suppresses colon carcinogenesis.

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    Ling Shao

    Full Text Available Colon carcinogenesis consists of a multistep process during which a series of genetic and epigenetic adaptations occur that lead to malignant transformation. Here, we have studied the role of A20 (also known as TNFAIP3, a ubiquitin-editing enzyme that restricts NFκB and cell death signaling, in intestinal homeostasis and tumorigenesis. We have found that A20 expression is consistently reduced in human colonic adenomas than in normal colonic tissues. To further investigate A20's potential roles in regulating colon carcinogenesis, we have generated mice lacking A20 specifically in intestinal epithelial cells and interbred these with mice harboring a mutation in the adenomatous polyposis coli gene (APC(min. While A20(FL/FL villin-Cre mice exhibit uninflamed intestines without polyps, A20(FL/FL villin-Cre APC(min/+ mice contain far greater numbers and larger colonic polyps than control APC(min mice. We find that A20 binds to the β-catenin destruction complex and restricts canonical wnt signaling by supporting ubiquitination and degradation of β-catenin in intestinal epithelial cells. Moreover, acute deletion of A20 from intestinal epithelial cells in vivo leads to enhanced expression of the β-catenin dependent genes cyclinD1 and c-myc, known promoters of colon cancer. Taken together, these findings demonstrate new roles for A20 in restricting β-catenin signaling and preventing colon tumorigenesis.

  3. Defining suitable reference genes for RT-qPCR analysis on intestinal epithelial cells.

    Science.gov (United States)

    Sirakov, Maria; Borra, Marco; Cambuli, Francesca Maria; Plateroti, Michelina

    2013-07-01

    The study of the mammalian intestinal epithelium concerns several aspects of cellular and molecular biology. In fact, most of these studies aim to define molecular components or mechanisms related with the control of stemness and the balance between cell proliferation and differentiation in physiopathological conditions. It is worth mentioning that real-time quantitative reverse transcription-polymerase chain reaction (RT-qPCR) approaches are commonly used, but only a few studies are available regarding suitable reference genes to normalize gene expression data. The present study was designed to validate potential reference genes in freshly isolated proliferating or differentiated epithelial cells from the mouse intestine. We also extended our analysis to the IEC6 intestinal epithelial cells, as a promising model to study intestinal physiopathology in vitro. The stability of six potential reference genes (Hprt1, Ppia, Gapdh, Rplp0, Ppib, and Vil1) has been tested both in epithelial cells isolated from the mouse intestine and in the IEC6 cell line. The software programs-geNorm and Normfinder-were used to obtain an estimation of the expression stability of each gene and, by comparing the results, to identify the most suitable genes for RT-qPCR data normalization. These multiple approaches allowed us to select different suitable reference genes for the correct quantification of mRNAs depending on the differentiated or proliferative nature of the cells.

  4. Fermented soya bean (tempe) extracts reduce adhesion of enterotoxigenic Escherichia coli to intestinal epithelial cells.

    Science.gov (United States)

    Roubos-van den Hil, P J; Nout, M J R; Beumer, R R; van der Meulen, J; Zwietering, M H

    2009-03-01

    This study aimed to investigate the effect of processed soya bean, during the successive stages of tempe fermentation and different fermentation times, on adhesion of enterotoxigenic Escherichia coli (ETEC) K88 to intestinal brush border cells as well as Caco-2 intestinal epithelial cells; and to clarify the mechanism of action. Tempe was prepared at controlled laboratory scale using Rhizopus microsporus var. microsporus as the inoculum. Extracts of raw, soaked and cooked soya beans reduced ETEC adhesion to brush border cells by 40%. Tempe extracts reduced adhesion by 80% or more. ETEC adhesion to Caco-2 cells reduced by 50% in the presence of tempe extracts. ETEC K88 bacteria were found to interact with soya bean extracts, and this may contribute to the observed decrease of ETEC adhesion to intestinal epithelial cells. Fermented soya beans (tempe) reduce the adhesion of ETEC to intestinal epithelial cells of pig and human origin. This reduced adhesion is caused by an interaction between ETEC K88 bacteria and soya bean compounds. The results strengthen previous observations on the anti-diarrhoeal effect of tempe. This effect indicates that soya-derived compounds may reduce adhesion of ETEC to intestinal cells in pigs as well as in humans and prevent against diarrhoeal diseases.

  5. Pregnane X receptor agonists enhance intestinal epithelial wound healing and repair of the intestinal barrier following the induction of experimental colitis.

    Science.gov (United States)

    Terc, Joshua; Hansen, Ashleigh; Alston, Laurie; Hirota, Simon A

    2014-05-13

    The intestinal epithelial barrier plays a key role in the maintenance of homeostasis within the gastrointestinal tract. Barrier dysfunction leading to increased epithelial permeability is associated with a number of gastrointestinal disorders including the inflammatory bowel diseases (IBD) - Crohn's disease and ulcerative colitis. It is thought that the increased permeability in patients with IBD may be driven by alterations in the epithelial wound healing response. To this end considerable study has been undertaken to identify signaling pathways that may accelerate intestinal epithelial wound healing and normalize the barrier dysfunction observed in IBD. In the current study we examined the role of the pregnane X receptor (PXR) in modulating the intestinal epithelial wound healing response. Mutations and reduced mucosal expression of the PXR are associated with IBD, and others have reported that PXR agonists can dampen intestinal inflammation. Furthermore, stimulation of the PXR has been associated with increased cell migration and proliferation, two of the key processes involved in wound healing. We hypothesized that PXR agonists would enhance intestinal epithelial repair. Stimulation of Caco-2 intestinal epithelial cells with rifaximin, rifampicin and SR12813, all potent agonists of the PXR, significantly increased wound closure. This effect was driven by p38 MAP kinase-dependent cell migration, and occurred in the absence of cell proliferation. Treating mice with a rodent specific PXR agonist, pregnenolone 16α-carbonitrile (PCN), attenuated the intestinal barrier dysfunction observed in the dextran sulphate sodium (DSS) model of experimental colitis, an effect that occurred independent of the known anti-inflammatory effects of PCN. Taken together our data indicate that the activation of the PXR can enhance intestinal epithelial repair and suggest that targeting the PXR may help to normalize intestinal barrier dysfunction observed in patients with IBD

  6. Immunohistochemical characterization of cellular proliferation in small intestinal hyperplasia of rats with hepatic Strobilocercus fasciolaris infection.

    Science.gov (United States)

    Lagapa, J T; Oku, Y; Kamiya, M

    2008-07-01

    Rats infected with the larvae of Taenia taeniaeformis harbour the intermediate stage of the parasite Strobilocercus fasciolaris within the liver. Affected animals also develop gastric and intestinal hyperplasia. The pathogenesis of the gastric hyperplasia has been extensively investigated, but few studies have addressed the nature of the intestinal changes. This study characterizes the proliferation of small intestinal epithelial cells by immunohistochemical labelling for proliferating cell nuclear antigen (PCNA) and bromodeoxyuridine (BrdU) uptake. At 6 weeks post-infection (wpi) there was an increase in villous length but crypt depth was normal. At 9 wpi there was evidence of epithelial hyperplasia, increased villous length and crypt depth, and expansion of zones of epithelial proliferation. Immunohistochemical labelling indicated that an increase in the number of proliferating cells produced a greater number of progeny cells. Intestinal hyperplasia during experimental infection with T. taeniaeformis larvae is likely to be related to the associated gastropathy, although the mechanisms underlying both changes remain undefined.

  7. TTC7A mutations disrupt intestinal epithelial apicobasal polarity

    NARCIS (Netherlands)

    Bigorgne, Amélie E; Farin, Henner F; Lemoine, Roxane; Mahlaoui, Nizar; Lambert, Nathalie; Gil, Marine; Schulz, Ansgar; Philippet, Pierre; Schlesser, Patrick; Abrahamsen, Tore G; Oymar, Knut; Davies, E Graham; Ellingsen, Christian Lycke; Leteurtre, Emmanuelle; Moreau-Massart, Brigitte; Berrebi, Dominique; Bole-Feysot, Christine; Nischke, Patrick; Brousse, Nicole; Fischer, Alain; Clevers, Hans; de Saint Basile, Geneviève

    2014-01-01

    Multiple intestinal atresia (MIA) is a rare cause of bowel obstruction that is sometimes associated with a combined immunodeficiency (CID), leading to increased susceptibility to infections. The factors underlying this rare disease are poorly understood. We characterized the immunological and intest

  8. Protective effects of Lactobacillus plantarum on epithelial barrier disruption caused by enterotoxigenic Escherichia coli in intestinal porcine epithelial cells.

    Science.gov (United States)

    Wu, Yunpeng; Zhu, Cui; Chen, Zhuang; Chen, Zhongjian; Zhang, Weina; Ma, Xianyong; Wang, Li; Yang, Xuefen; Jiang, Zongyong

    2016-04-01

    Tight junctions (TJs) play an important role in maintaining the mucosal barrier function and gastrointestinal health of animals. Lactobacillus plantarum (L. plantarum) was reported to protect the intestinal barrier function of early-weaned piglets against enterotoxigenic Escherichia coli (ETEC) K88 challenge; however, the underlying cellular mechanism of this protection was unclear. Here, an established intestinal porcine epithelia cell (IPEC-J2) model was used to investigate the protective effects and related mechanisms of L. plantarum on epithelial barrier damages induced by ETEC K88. Epithelial permeability, expression of inflammatory cytokines, and abundance of TJ proteins, were determined. Pre-treatment with L. plantarum for 6h prevented the reduction in transepithelial electrical resistance (TEER) (Pplantarum were higher (Pplantarum was shown to regulate proteins of nuclear factor κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways. These results indicated that L. plantarum may improve epithelial barrier function by maintenance of TEER, inhibiting the reduction of TJ proteins, and reducing the expression of proinflammatory cytokines induced by ETEC K88, possibly through modulation of TLRs, NF-κB and MAPK pathways.

  9. Intestinal epithelial cells and their role in innate mucosal immunity

    OpenAIRE

    Maldonado-Contreras, A. L.; McCormick, Beth A

    2010-01-01

    The mucosal surfaces of the respiratory, gastrointestinal and urogenital tracts are covered by a layer of epithelial cells that are responsible for sensing and promoting a host immune response in order to establish the limits not only for commensal microorganisms but also for foreign organisms or particles. This is a remarkable task as the human body represents a composite of about 10 trillion human-self cells plus non-self cells from autochthonous or indigenous microbes that outnumber human ...

  10. Antigen presentation by small intestinal epithelial cells uniquely enhances IFN-γ secretion from CD4{sup +} intestinal intraepithelial lymphocytes

    Energy Technology Data Exchange (ETDEWEB)

    Hatano, Ryo; Yamada, Kiyoshi; Iwamoto, Taku; Maeda, Nana; Emoto, Tetsuro; Shimizu, Makoto; Totsuka, Mamoru, E-mail: atotuka@mail.ecc.u-tokyo.ac.jp

    2013-06-14

    Highlights: •Small intestinal epithelial cells (sIECs). •sIECs are able to induce antigen specific proliferation of CD4{sup +} IELs. •sIECs induce markedly enhanced IFN-γ secretion by CD4{sup +} IELs. •Induction of enhanced IFN-γ secretion by sIECs is uniquely observed in CD4{sup +} IELs. -- Abstract: Small intestinal epithelial cells (sIECs) express major histocompatibility complex class II molecules even in a normal condition, and are known to function as antigen presenting cells (APCs) at least in vitro. These findings raised the possibility that sIECs play an important role in inducing immune responses against luminal antigens, especially those of intestinal intraepithelial lymphocytes (IELs) and lamina propria lymphocytes (LPLs). We herein showed that antigenic stimulation with sIECs induced markedly greater secretion of interferon-gamma (IFN-γ) by CD4{sup +} IELs, but not interleukin (IL)-4, IL-10 and IL-17 although the proliferative response was prominently lower than that with T cell-depleted splenic APCs. In contrast, no enhanced IFN-γ secretion by CD4{sup +} LPLs and primed splenic CD4{sup +} T cells was observed when stimulated with sIECs. Taken together, these results suggest that sIECs uniquely activate CD4{sup +} IELs and induce remarkable IFN-γ secretion upon antigenic stimulation in vivo.

  11. Involvement of Concentrative Nucleoside Transporter 1 in Intestinal Absorption of Trifluridine Using Human Small Intestinal Epithelial Cells.

    Science.gov (United States)

    Takahashi, Koichi; Yoshisue, Kunihiro; Chiba, Masato; Nakanishi, Takeo; Tamai, Ikumi

    2015-09-01

    TAS-102, which is effective for refractory metastatic colorectal cancer, is a combination drug of anticancer trifluridine (FTD; which is derived from pyrimidine nucleoside) and FTD-metabolizing enzyme inhibitor tipiracil hydrochloride (TPI) at a molecular ratio of 1:0.5. To evaluate the intestinal absorption mechanism of FTD, the uptake and transcellular transport of FTD by human small intestinal epithelial cell (HIEC) monolayer as a model of human intestinal epithelial cells was investigated. The uptake and membrane permeability of FTD by HIEC monolayers were saturable, Na(+) -dependent, and inhibited by nucleosides. These transport characteristics are mostly comparable with those of concentrative nucleoside transporters (CNTs). Moreover, the uptake of FTD by CNT1-expressing Xenopus oocytes was the highest among human CNT transporters. The obtained Km and Vmax values of FTD by CNT1 were 69.0 μM and 516 pmol/oocyte/30 min, respectively. The transcellular transport of FTD by Caco-2 cells, where CNT1 is heterologously expressed, from apical to basolateral side was greater than that by Mock cells. In conclusion, these results demonstrated that FTD exhibits high oral absorption by the contribution of human CNT1. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

  12. Permissiveness of bovine epithelial cells from lung, intestine, placenta and udder for infection with Coxiella burnetii.

    Science.gov (United States)

    Sobotta, Katharina; Bonkowski, Katharina; Liebler-Tenorio, Elisabeth; Germon, Pierre; Rainard, Pascal; Hambruch, Nina; Pfarrer, Christiane; Jacobsen, Ilse D; Menge, Christian

    2017-04-12

    Ruminants are the main source of human infections with the obligate intracellular bacterium Coxiella (C.) burnetii. Infected animals shed high numbers of C. burnetii by milk, feces, and birth products. In goats, shedding by the latter route coincides with C. burnetii replication in epithelial (trophoblast) cells of the placenta, which led us to hypothesize that epithelial cells are generally implicated in replication and shedding of C. burnetii. We therefore aimed at analyzing the interactions of C. burnetii with epithelial cells of the bovine host (1) at the entry site (lung epithelium) which govern host immune responses and (2) in epithelial cells of gut, udder and placenta decisive for the quantity of pathogen excretion. Epithelial cell lines [PS (udder), FKD-R 971 (small intestine), BCEC (maternal placenta), F3 (fetal placenta), BEL-26 (lung)] were inoculated with C. burnetii strains Nine Mile I (NMI) and NMII at different cultivation conditions. The cell lines exhibited different permissiveness for C. burnetii. While maintaining cell viability, udder cells allowed the highest replication rates with formation of large cell-filling Coxiella containing vacuoles. Intestinal cells showed an enhanced susceptibility to invasion but supported C. burnetii replication only at intermediate levels. Lung and placental cells also internalized the bacteria but in strikingly smaller numbers. In any of the epithelial cells, both Coxiella strains failed to trigger a substantial IL-1β, IL-6 and TNF-α response. Epithelial cells, with mammary epithelial cells in particular, may therefore serve as a niche for C. burnetii replication in vivo without alerting the host's immune response.

  13. Eicosanoid receptors: Targets for the treatment of disrupted intestinal epithelial homeostasis.

    Science.gov (United States)

    Moreno, Juan J

    2017-02-05

    The importance of cyclooxygenase and lipoxygenase pathways and the consequent eicosanoid synthesis in the physiology and pathophysiology of the intestinal epithelium is currently being established. Each eicosanoid (prostanoid, leukotriene, hydroxyeicosatetraenoic acid) preferentially recognizes one or more receptors coupled to one or more signal-transduction processes. This overview focuses on the role of eicosanoid receptors in the maintenance of intestinal epithelium physiology through the control of proliferation/differentiation/apoptosis processes. Furthermore, it is reported that the role of these receptors on the regulation of the barrier function of the intestinal epithelium have arisen through the regulation of absorption/secretion processes, tight-junction state and the control of the intestinal immune response. Also, this review considers the implication of AA cascade in the disruption of epithelial homeostasis during inflammatory bowel diseases and colorectal cancer as well as the therapeutic values and potential of the eicosanoid receptors as novel targets for the treatments of the pathologies above mentioned.

  14. Epithelial-connective tissue cross-talk is essential for regeneration of intestinal epithelium.

    Science.gov (United States)

    Ishizuya-Oka, Atsuko

    2005-02-01

    Epithelial cells of the gastrointestine undergo a rapid cell-renewal and originate from stem cells throughout the life of the organisms. Previous studies have provided a solid body of evidence to show that the epithelial cell-renewal is under the strict control of cell-cell and cell-extracellular matrix (ECM) interactions between the epithelium and the connective tissue. Especially, the microenvironment around the stem cells called "niche" is thought to play important roles in this control, and its disruption leads to diseases or disorders such as cancer in the human gastrointestine. Although understanding how the niche affects the stem cells is clinically important, its mechanisms still remain mostly unknown at the molecular level, possibly due to difficulties in the identification of the stem cells in the gastrointestine. Recent progress in cell and molecular biology is gradually beginning to shed light on some of the key signaling pathways in the cell-renewal of the intestinal epithelium, such as Wnt/T-cell factor (TCF)/beta-catenin, Notch, Sonic hedgehog (Shh)/bone morphogenetic protein (BMP) signaling pathways, which are also involved in embryonic organogenesis and/or adult carcinogenesis. At present, only fragmentary information is available on their precise functions in the intestine. Nevertheless, there is a growing body of evidence that such signaling pathways have conservative functions in the intestine throughout terrestrial vertebrates, suggesting the usefulness of experimental animals to clarify molecular mechanisms regulating epithelial cell-renewal. In this article, I review some recent findings in this field, with particular focus on our studies using the Xenopus laevis intestine, where the stem cells form the mammalian-type intestinal epithelium under the control of connective tissue during metamorphosis. This Xenopus experimental system will certainly serve as a useful model for the study of the intestinal niche, whose clarification is urgently

  15. Effect of Psychoneural Factors on Intestinal Epithelial Function

    Directory of Open Access Journals (Sweden)

    M Cecilia Berin

    1997-01-01

    Full Text Available Stress has been associated with abnormal gastrointestinal function, including diarrhea and abdominal pain, and stress-associated gastric ulceration has frequently been documented. Stress can also exacerbate ongoing pathophysiology and often precedes relapses in patients with inflammatory bowel disease or irritable bowel syndrome. The relatively new field of psychoneuroimmunology is involved with the elucidation of mechanisms that explain the link between the central nervous system and immune-mediated pathophysiology. Recent progress examining the interaction among the nervous system, the immune system and the epithelium of the intestine is discussed, and the evidence for central nervous sysytem control of this interaction is examined.

  16. Microbiota regulate intestinal epithelial gene expression by suppressing the transcription factor Hepatocyte nuclear factor 4 alpha

    Science.gov (United States)

    Davison, James M.; Lickwar, Colin R.; Song, Lingyun; Breton, Ghislain; Crawford, Gregory E.; Rawls, John F.

    2017-01-01

    Microbiota influence diverse aspects of intestinal physiology and disease in part by controlling tissue-specific transcription of host genes. However, host genomic mechanisms mediating microbial control of intestinal gene expression are poorly understood. Hepatocyte nuclear factor 4 (HNF4) is the most ancient family of nuclear receptor transcription factors with important roles in human metabolic and inflammatory bowel diseases, but a role in host response to microbes is unknown. Using an unbiased screening strategy, we found that zebrafish Hnf4a specifically binds and activates a microbiota-suppressed intestinal epithelial transcriptional enhancer. Genetic analysis revealed that zebrafish hnf4a activates nearly half of the genes that are suppressed by microbiota, suggesting microbiota negatively regulate Hnf4a. In support, analysis of genomic architecture in mouse intestinal epithelial cells disclosed that microbiota colonization leads to activation or inactivation of hundreds of enhancers along with drastic genome-wide reduction of HNF4A and HNF4G occupancy. Interspecies meta-analysis suggested interactions between HNF4A and microbiota promote gene expression patterns associated with human inflammatory bowel diseases. These results indicate a critical and conserved role for HNF4A in maintaining intestinal homeostasis in response to microbiota. PMID:28385711

  17. Establishment of primary bovine intestinal epithelial cell culture and clone method.

    Science.gov (United States)

    Zhan, Kang; Lin, Miao; Liu, Ming-Mei; Sui, Yang-Nan; Zhao, Guo-Qi

    2017-01-01

    The aim of this study was to establish bovine intestinal epithelial cell (BIEC) line and provide a novel clone cell method. Although various strategies of bovine cell culture and clone techniques have been reported, these methods remain not established. Here, we culture successfully primary BIECs and establish a novel clone cell method. Our result showed that BIECs could be successfully cultured and passaged about generation 5. These cellular aggregates and clusters were adherent loosely at day 2 of culture. Cell aggregates and clusters start to proliferate after approximately 4 d. The BIECs showed positive reaction against cytokeratin 18, E-cadherin, and characteristics of epithelial-like morphology. In addition, the fatty acid-binding proteins (FABPs), villin, and intestinal peptidase (IP) band were positive in BIECs. Our results suggest that the establishment of culturing and clone BIEC methods will apply to isolate and clone other primary cells. These BIECs could therefore contribute to the study of bovine intestinal nutrient absorption and regulation, immune regulation, and the pathogenesis of the bovine intestinal disease, which will provide intestinal cell model in vitro.

  18. Butyrate stimulates IL-32α expression in human intestinal epithelial cell lines

    Institute of Scientific and Technical Information of China (English)

    Ayako; Kobori; Shigeki; Bamba; Hirotsugu; Imaeda; Hiromitsu; Ban; Tomoyuki; Tsujikawa; Yasuharu; Saito; Yoshihide; Fujiyama; Akira; Andoh

    2010-01-01

    AIM: To investigate the effects of butyrate on interleukin (IL)-32α expression in epithelial cell lines. METHODS: The human intestinal epithelial cell lines HT-29, SW480, and T84 were used. Intracellular IL- 32α was determined by Western blotting analyses. IL- 32α mRNA expression was analyzed by real-time poly-merase chain reaction. RESULTS: Acetate and propionate had no effects on IL-32α mRNA expression. Butyrate significantly enhanced IL-32α expression in all cell lines. Butyrate also up-regulated IL-1β-i...

  19. Epithelial Cell Damage Activates Bactericidal/Permeability Increasing-Protein (BPI Expression in Intestinal Epithelium

    Directory of Open Access Journals (Sweden)

    Arjun Balakrishnan

    2017-08-01

    Full Text Available As the first line of defense against invading pathogen, intestinal epithelium produces various antimicrobial proteins (AMP that help in clearance of pathogen. Bactericidal/permeability-increasing protein (BPI is a 55 kDa AMP that is expressed in intestinal epithelium. Dysregulation of BPI in intestinal epithelium is associated with various inflammatory diseases like Crohn’s Disease, Ulcerative colitis, and Infectious enteritis’s. In this paper, we report a direct correlation between intestinal damage and BPI expression. In Caco-2 cells, we see a significant increase in BPI levels upon membrane damage mediated by S. aureus infection and pore-forming toxins (Streptolysin and Listeriolysin. Cells detect changes in potassium level as a Danger-associated molecular pattern associated with cell damage and induce BPI expression in a p38 dependent manner. These results are further supported by in vivo findings that the BPI expression in murine intestinal epithelium is induced upon infection with bacteria which cause intestinal damage (Salmonella Typhimurium and Shigella flexneri whereas mutants that do not cause intestinal damage (STM ΔfliC and STM ΔinvC did not induce BPI expression. Our results suggest that epithelial damage associated with infection act as a signal to induce BPI expression.

  20. Molecular properties of adult mouse gastric and intestinal epithelial progenitors in their niches

    DEFF Research Database (Denmark)

    Giannakis, Marios; Stappenbeck, Thaddeus S; Mills, Jason C

    2006-01-01

    We have sequenced 36,641 expressed sequence tags from laser capture microdissected adult mouse gastric and small intestinal epithelial progenitors, obtaining 4031 and 3324 unique transcripts, respectively. Using Gene Ontology (GO) terms, each data set was compared with cDNA libraries from intact...... adult stomach and small intestine. Genes in GO categories enriched in progenitors were filtered against genes in GO categories represented in hematopoietic, neural, and embryonic stem cell transcriptomes and mapped onto transcription factor networks, plus canonical signal transduction and metabolic...

  1. Lineage-specific expression of bestrophin-2 and bestrophin-4 in human intestinal epithelial cells

    DEFF Research Database (Denmark)

    Ito, Go; Okamoto, Ryuichi; Murano, Tatsuro

    2013-01-01

    Intestinal epithelial cells (IECs) regulate the absorption and secretion of anions, such as HCO3(-) or Cl(-). Bestrophin genes represent a newly identified group of calcium-activated Cl(-) channels (CaCCs). Studies have suggested that, among the four human bestrophin-family genes, bestrophin-2...... (BEST2) and bestrophin-4 (BEST4) might be expressed within the intestinal tissue. Consistently, a study showed that BEST2 is expressed by human colonic goblet cells. However, their precise expression pattern along the gastrointestinal tract, or the lineage specificity of the cells expressing these genes...

  2. Specific responses in rat small intestinal epithelial mRNA expression and protein levels during chemotherapeutic damage and regeneration

    NARCIS (Netherlands)

    M. Verburg (Melissa); I.B. Renes (Ingrid); D.J. van Nispen; S. Ferdinandusse; M. Jorritsma; H.A. Büller (Hans); A.W.C. Einerhand (Sandra); J. Dekker (Jan)

    2002-01-01

    textabstractThe rapidly dividing small intestinal epithelium is very sensitive to the cytostatic drug methotrexate. We investigated the regulation of epithelial gene expression in rat jejunum during methotrexate-induced damage and regeneration. Ten differentiation markers were loca

  3. Interaction with intestinal epithelial cells promotes an immunosuppressive phenotype in Lactobacillus casei.

    Directory of Open Access Journals (Sweden)

    Minna Tiittanen

    Full Text Available Maintenance of the immunological tolerance and homeostasis in the gut is associated with the composition of the intestinal microbiota. We here report that cultivation of Lactobacillus casei ATCC 334 in the presence of human intestinal epithelial cells promotes functional changes in bacteria. In particular, the interaction enhanced the immunosuppressive phenotype of L. casei as demonstrated by the ability of L. casei to generate functional regulatory T cells (CD4+CD25+FoxP3+ and production of the anti-inflammatory cytokine interleukin-10 by human peripheral blood mononuclear cells. The results indicate microbe-host cross-talk that changes features of microbes, and suggest that in vitro simulation of epithelial cell interaction can reveal functional properties of gut microbes more accurately than conventional cultivation.

  4. Phytic acid protects porcine intestinal epithelial cells from deoxynivalenol (DON) cytotoxicity.

    Science.gov (United States)

    Pacheco, Graziela Drociunas; Silva, Caio Abércio da; Pinton, Philippe; Oswald, Isabelle P; Bracarense, Ana Paula Frederico Rodrigues Loureiro

    2012-05-01

    The purpose of this study was to evaluate the effects of phytic acid (IP(6)) as a possible inhibitor of cellular damage induced by toxic substances such as mycotoxins on a porcine intestinal epithelial cell line (IPEC-1). We first observed that a dose of 5 mM phytic acid decreases cell viability and transepithelial electrical resistance (TEER) of cell monolayer. We next investigate the effect of non-cytotoxic dose of phytic acid on the deoxinivalenol (DON) induced decreased TEER. We showed that treatment with 0.5 mM or 1.0 mM phytic acid restores the decrease in TEER caused by 25 μM DON. In conclusion this study demonstrates that phytic acid decreased the negative effects of deoxynivalenol on the membrane integrity of the IPEC-1 intestinal epithelial cell line.

  5. Evaluation of preparation methods for MS-based analysis of intestinal epithelial cell proteomes

    DEFF Research Database (Denmark)

    Hesselager, Marianne Overgaard; Codrea, Marius Cosmin; Bendixen, Emøke

    2015-01-01

    The gut epithelium formed between an organism and the environment plays an essential role in host–microbe interactions, yet remains one of the least characterized mammalian tissues. Especially the membrane proteins, which are critical to bacterial adhesion, are understudied, because these proteins...... are low in abundance, and large amounts of sample is needed for their preparation and for undertaking MS-based analysis. The aim of this study was to evaluate three different methods for isolation and preparation of pig intestinal epithelial cells for MS-based analysis of the proteome. Samples were...... of ease and speed of sample preparation, as well as protein recovery. In comparison, more gentle methods where intestinal epithelial cells are harvested by shaking are more time consuming, result in lower protein yield, and are prone to increased technical variation due to multiple steps involved....

  6. Precision-cut intestinal slices as a culture system to analyze the infection of differentiated intestinal epithelial cells by avian influenza viruses.

    Science.gov (United States)

    Punyadarsaniya, Darsaniya; Winter, Christine; Mork, Ann-Kathrin; Amiri, Mahdi; Naim, Hassan Y; Rautenschlein, Silke; Herrler, Georg

    2015-02-01

    Many viruses infect and replicate in their host via the intestinal tract, e.g. many picornaviruses, several coronaviruses and avian influenza viruses of waterfowl. To analyze infection of enterocytes is a challenging task as culture systems for differentiated intestinal epithelial cells are not readily available and often have a life span that is too short for infection studies. Precision-cut intestinal slices (PCIS) from chicken embryos were prepared and shown that the epithelial cells lining the lumen of the intestine are viable for up to 4 days. Using lectin staining, it was demonstrated that α2,3-linked sialic acids, the preferred receptor determinants of avian influenza viruses, are present on the apical side of the epithelial cells. Furthermore, the epithelial cells (at the tips) of the villi were shown to be susceptible to infection by an avian influenza virus of the H9N2 subtype. This culture system will be useful to analyze virus infection of intestinal epithelial cells and it should be applicable also to the intestine of other species. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Human intestinal epithelial cells produce proinflammatory cytokines in response to infection in a SCID mouse-human intestinal xenograft model of amebiasis.

    Science.gov (United States)

    Seydel, K B; Li, E; Swanson, P E; Stanley, S L

    1997-01-01

    The protozoan parasite Entamoeba histolytica causes amebic dysentery and amebic liver abscess, diseases associated with significant morbidity and mortality worldwide. E. histolytica infection appears to involve the initial attachment of amebic trophozoites to intestinal epithelial cells, followed by lysis of these cells and subsequent invasion into the submucosa. A recent in vitro study (L. Eckmann, S. L. Reed, J. R. Smith, and M. F. Kagnoff, J. Clin. Invest. 96:1269-1279, 1995) demonstrated that incubation of E. histolytica trophozoites with epithelial cell lines results in epithelial cell production of inflammatory cytokines, including interleukin-1 (IL-1) and IL-8, suggesting that intestinal epithelial cell production of cytokines might play a role in the inflammatory response and tissue damage seen in intestinal amebiasis. To determine whether intestinal epithelial cell production of IL-1 and IL-8 occurs in response to E. histolytica infection in vivo and as an approach to studying the specific interactions between amebic trophozoites and human intestine, we used a SCID mouse-human intestinal xenograft (SCID-HU-INT) model of disease, where human intestinal xenografts were infected with virulent E. histolytica trophozoites. Infection of xenografts with E. histolytica trophozoites resulted in extensive tissue damage, which was associated with the development of an early inflammatory response composed primarily of neutrophils. Using oligonucleotide primers that specifically amplify human IL-1beta and IL-8, we could demonstrate by reverse transcription PCR that mRNA for both IL-1beta and IL-8 is produced by human intestinal xenografts in response to amebic infection. The increase in human intestinal IL-1beta and IL-8 in response to invasive amebiasis was confirmed by enzyme-linked immunosorbent assays specific for human IL-1beta and IL-8. Using immunohistochemistry, we confirmed that human intestinal epithelial cells were the source of IL-8 in infected xenografts

  8. Signaling pathways induced by serine proteases to increase intestinal epithelial barrier function.

    Science.gov (United States)

    Lahey, Kelcie A; Ronaghan, Natalie J; Shang, Judie; Dion, Sébastien P; Désilets, Antoine; Leduc, Richard; MacNaughton, Wallace K

    2017-01-01

    Changes in barrier function of the gastrointestinal tract are thought to contribute to the inflammatory bowel diseases Crohn's disease and ulcerative colitis. Previous work in our lab demonstrated that apical exposure of intestinal epithelial cell lines to serine proteases results in an increase in transepithelial electrical resistance (TER). However, the underlying mechanisms governing this response are unclear. We aimed to determine the requirement for proteolytic activity, epidermal growth factor receptor (EGFR) activation, and downstream intracellular signaling in initiating and maintaining enhanced barrier function following protease treatment using a canine intestinal epithelial cell line (SCBN). We also examined the role of phosphorylation of myosin regulatory light chain on the serine protease-induced increase in TER through. It was found that proteolytic activity of the serine proteases trypsin and matriptase is required to initiate and maintain the protease-mediated increase in TER. We also show that MMP-independent EGFR activation is essential to the sustained phase of the protease response, and that Src kinases may mediate EGFR transactivation. PI3-K and ERK1/2 signaling were important in reaching a maximal increase in TER following protease stimulation; however, their upstream activators are yet to be determined. CK2 inhibition prevented the increase in TER induced by serine proteases. The bradykinin B(2) receptor was not involved in the change in TER in response to serine proteases, and no change in phosphorylation of MLC was observed after trypsin or matriptase treatment. Taken together, our data show a requirement for ongoing proteolytic activity, EGFR transactivation, as well as downstream PI3-K, ERK1/2, and CK2 signaling in protease-mediated barrier enhancement of intestinal epithelial cells. The pathways mediating enhanced barrier function by proteases may be novel therapeutic targets for intestinal disorders characterized by disrupted epithelial

  9. Intestinal epithelial barrier function and tight junction proteins with heat and exercise

    DEFF Research Database (Denmark)

    Dokladny, Karol; Zuhl, Micah N; Moseley, Pope L

    2016-01-01

    (passive hyperthermia) heat stress on tight junction barrier function in in vitro and in vivo (animals and humans) models. Our secondary focus is to review changes in tight junction proteins in response to exercise or hyperthermic conditions. Finally, we discuss some pharmacological or nutritional...... interventions that may affect the cellular mechanisms involved in maintaining homeostasis of the intestinal epithelial tight junction barrier during heat stress or exercise....

  10. Exogenous HIV-1 Nef upsets the IFN-γ-induced impairment of human intestinal epithelial integrity.

    Directory of Open Access Journals (Sweden)

    Maria Giovanna Quaranta

    Full Text Available BACKGROUND: The mucosal tissues play a central role in the transmission of HIV-1 infection as well as in the pathogenesis of AIDS. Despite several clinical studies reported intestinal dysfunction during HIV infection, the mechanisms underlying HIV-induced impairments of mucosal epithelial barrier are still unclear. It has been postulated that HIV-1 alters enterocytic function and HIV-1 proteins have been detected in several cell types of the intestinal mucosa. In the present study, we analyzed the effect of the accessory HIV-1 Nef protein on human epithelial cell line. METHODOLOGY/PRINCIPAL FINDINGS: We used unstimulated or IFN-γ-stimulated Caco-2 cells, as a model for homeostatic and inflamed gastrointestinal tracts, respectively. We investigated the effect of exogenous recombinant Nef on monolayer integrity analyzing its uptake, transepithelial electrical resistance, permeability to FITC-dextran and the expression of tight junction proteins. Moreover, we measured the induction of proinflammatory mediators. Exogenous Nef was taken up by Caco-2 cells, increased intestinal epithelial permeability and upset the IFN-γ-induced reduction of transepithelial resistance, interfering with tight junction protein expression. Moreover, Nef inhibited IFN-γ-induced apoptosis and up-regulated TNF-α, IL-6 and MIP-3α production by Caco-2 cells while down-regulated IL-10 production. The simultaneous exposure of Caco-2 cells to Nef and IFN-γ did not affect cytokine secretion respect to untreated cells. Finally, we found that Nef counteracted the IFN-γ induced arachidonic acid cascade. CONCLUSION/SIGNIFICANCE: Our findings suggest that exogenous Nef, perturbing the IFN-γ-induced impairment of intestinal epithelial cells, could prolong cell survival, thus allowing for accumulation of viral particles. Our results may improve the understanding of AIDS pathogenesis, supporting the discovery of new therapeutic interventions.

  11. Ultrastructural study of adhesion of enterotoxigenic Escherichia coli to erythrocytes and human intestinal epithelial cells.

    OpenAIRE

    1984-01-01

    The adhesion to erythrocytes and human intestinal epithelial cells of enterotoxigenic Escherichia coli strains H10407, B2C, and H10407P, expressing colonization factor antigen I (CFA/I), CFA/II, and type 1 fimbriae, respectively, was examined by electron microscopy. CFA and type 1 fimbriae were visualized by negative staining in thin sections after en bloc staining with ruthenium red and by immune labeling with antisera raised against purified fimbriae. By negative and ruthenium red staining,...

  12. Molting, Ecdysis, and Reproduction of Trichinella spiralis Are Supported In Vitro by Intestinal Epithelial Cells

    OpenAIRE

    Gagliardo, L. F.; McVay, C S; Appleton, J.A.

    2002-01-01

    Trichinella spiralis is an obligate parasite of animals that has an unusual intracellular life cycle. Investigation of parasitism at the cellular and molecular levels has been challenging because of a shortage of tools for in vitro cultivation of T. spiralis. We have found that T. spiralis larvae molt, ecdyse, develop to adulthood, and reproduce when they are inoculated onto cultured intestinal epithelial cells. Initially, larvae invade and migrate through cells in a monolayer (T. ManWarren, ...

  13. Effect of serum, fibronectin, and laminin on adhesion of rabbit intestinal epithelial cells in culture.

    Science.gov (United States)

    Burrill, P H; Bernardini, I; Kleinman, H K; Kretchmer, N

    1981-01-01

    Rabbit intestinal epithelial cells, obtained after a limited hyaluronidase digestion, were incubated in medium with or without calf serum, on bacteriological plastic dishes. The dishes, either plain or coated with an air-dried type I collagen film, were pretreated with medium alone or eith medium containing purified laminin or purified fibronectin. Cells did not attach in significant numbers to untreated bacteriological plastic, even in the presence of serum. Cells did attach to collagen-coated dishes, and were judged viable on the basis of their incorporation of radiolabeled leucine into cell protein. Cell adhesion to the collagen substrate increased in proportion to the concentration of serum in the medium, with maximal attachment of 5% serum or greater. Pretreatment of plain or collagen-coated dishes with increasing amounts of fibronectin enhanced cell adhesion in a concentration-dependent manner. Either serum, or fibronectin-free serum in the medium enhanced cell attachment to substrates pretreated with either fibronectin or laminin. Thus, intestinal epithelial cells appear to possess surface receptors for both laminin and fibronectin. The evidence further suggests that calf serum may contain factors, other than fibronectin, capable of enhancing intestinal epithelial cell attachment to collagen substrates.

  14. Food Contaminant Zearalenone and Its Metabolites Affect Cytokine Synthesis and Intestinal Epithelial Integrity of Porcine Cells

    Science.gov (United States)

    Marin, Daniela E.; Motiu, Monica; Taranu, Ionelia

    2015-01-01

    The intestinal epithelium is the first barrier against food contaminants. Zearalenone (ZEN) is an estrogenic mycotoxin that was identified as a common contaminant of cereal grains and food and feedstuffs. In the present study, we have investigated the in vitro effects of ZEN and some of its metabolites (α-ZOL, β-ZOL) in concentrations of 10–100 µM on a swine epithelial cell line: Intestinal porcine epithelial cells (IPEC-1). We demonstrated that both ZEN metabolites were more toxic for IPEC cells as resulted from the XTT test, while for doses lower than 10 µM, only β-ZOL showed a more pronounced cytotoxicity versus epithelial cells as resulted from neutral red assay. ZEN has no effect on TER values, while α-ZOL significantly decreased the TER values, starting with day 4 of treatment. β-ZOL had a dual effect, firstly it induced a significant increase of TER, and then, starting on day 6, it induced a dramatic decrease of TER values as compared with on day 0. Concerning the cytokine synthesis, our results showed that ZEN has a tendency to increase the synthesis of IL-8 and IL-10. By contrast, α- and β-ZOL decreased the expression of both IL-8 and IL-10, in a dose dependent manner. In conclusion, our results showed that ZEN and its metabolites differently affected porcine intestinal cell viability, transepithelial resistance and cytokine synthesis with important implication for gut health. PMID:26035492

  15. Food contaminant zearalenone and its metabolites affect cytokine synthesis and intestinal epithelial integrity of porcine cells.

    Science.gov (United States)

    Marin, Daniela E; Motiu, Monica; Taranu, Ionelia

    2015-05-29

    The intestinal epithelium is the first barrier against food contaminants. Zearalenone (ZEN) is an estrogenic mycotoxin that was identified as a common contaminant of cereal grains and food and feedstuffs. In the present study, we have investigated the in vitro effects of ZEN and some of its metabolites (α-ZOL, β-ZOL) in concentrations of 10-100 µM on a swine epithelial cell line: Intestinal porcine epithelial cells (IPEC-1). We demonstrated that both ZEN metabolites were more toxic for IPEC cells as resulted from the XTT test, while for doses lower than 10 µM, only β-ZOL showed a more pronounced cytotoxicity versus epithelial cells as resulted from neutral red assay. ZEN has no effect on TER values, while α-ZOL significantly decreased the TER values, starting with day 4 of treatment. β-ZOL had a dual effect, firstly it induced a significant increase of TER, and then, starting on day 6, it induced a dramatic decrease of TER values as compared with on day 0. Concerning the cytokine synthesis, our results showed that ZEN has a tendency to increase the synthesis of IL-8 and IL-10. By contrast, α- and β-ZOL decreased the expression of both IL-8 and IL-10, in a dose dependent manner. In conclusion, our results showed that ZEN and its metabolites differently affected porcine intestinal cell viability, transepithelial resistance and cytokine synthesis with important implication for gut health.

  16. Protective effects of Rheum tanguticum polysaccharide against hydrogen peroxide-induced intestinal epithelial cell injury

    Institute of Scientific and Technical Information of China (English)

    Lin-Na Liu; Qi-Bing Mei; Li Liu; Feng Zhang; Zhen-Guo Liu; Zhi-Peng Wang; Ru-Tao Wang

    2005-01-01

    AIM: To describe the effect of Rheum tanguticum polysaccharide (RTP) on hydrogen peroxide-induced human intestinal epithelial cell injury.METHODS: Hydrogen peroxide (100 μmol/L) was introduced to induce human intestinal epithelial cell injury.Cells were pretreated with RTP (30,100,300 μg/mL) for 24 h before exposure to hydrogen peroxide. Cell viability was detected by MTr assay and morphological observation.Acridine orange staining and flow cytometry were performed to assess cell apoptosis. Lactate dehydrogenase (LDH) activity, production of malondialdehyde (MDA) and superoxide dismutase (SOD) activity were measured by spectrophotometry with corresponding assay kits.RESULTS: Following exposure to H2O2, a marked decrease in cell survival and SOD activity, increased production of MDA, LDH leakage and cell apoptosis were found.Pretreatment of the cells with RTP could significantly elevate cell survival, SOD activity and decrease the level of MDA, LDH activity and cell apoptosis.CONCLUSION: RTP may have cytoprotective and antioxidant effects against H2O2-induced intestinal epithelial cell injury by inhibiting cell apoptosis and necrosis. This might be one of the possible mechanisms of RTP for the treatment of ulcerative colitis in rats.

  17. Giardia duodenalis Surface Cysteine Proteases Induce Cleavage of the Intestinal Epithelial Cytoskeletal Protein Villin via Myosin Light Chain Kinase.

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    Amol Bhargava

    Full Text Available Giardia duodenalis infections are among the most common causes of waterborne diarrhoeal disease worldwide. At the height of infection, G. duodenalis trophozoites induce multiple pathophysiological processes within intestinal epithelial cells that contribute to the development of diarrhoeal disease. To date, our understanding of pathophysiological processes in giardiasis remains incompletely understood. The present study reveals a previously unappreciated role for G. duodenalis cathepsin cysteine proteases in intestinal epithelial pathophysiological processes that occur during giardiasis. Experiments first established that Giardia trophozoites indeed produce cathepsin B and L in strain-dependent fashion. Co-incubation of G. duodenalis with human enterocytes enhanced cathepsin production by Assemblage A (NF and S2 isolates trophozoites, but not when epithelial cells were exposed to Assemblage B (GSM isolate trophozoites. Direct contact between G. duodenalis parasites and human intestinal epithelial monolayers resulted in the degradation and redistribution of the intestinal epithelial cytoskeletal protein villin; these effects were abolished when parasite cathepsin cysteine proteases were inhibited. Interestingly, inhibition of parasite proteases did not prevent degradation of the intestinal tight junction-associated protein zonula occludens 1 (ZO-1, suggesting that G. duodenalis induces multiple pathophysiological processes within intestinal epithelial cells. Finally, this study demonstrates that G. duodenalis-mediated disruption of villin is, at least, in part dependent on activation of myosin light chain kinase (MLCK. Taken together, this study indicates a novel role for parasite cathepsin cysteine proteases in the pathophysiology of G. duodenalis infections.

  18. Lentiviral-Mediated Transgene Expression Can Potentiate Intestinal Mesenchymal-Epithelial Signaling

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    Dismuke Adria D

    2009-07-01

    Full Text Available Abstract Mesenchymal-epithelial signaling is essential for the development of many organs and is often disrupted in disease. In this study, we demonstrate the use of lentiviral-mediated transgene delivery as an effective approach for ectopic transgene expression and an alternative to generation of transgenic animals. One benefit to this approach is that it can be used independently or in conjunction with established transgenic or knockout animals for studying modulation of mesenchymal-epithelial interactions. To display the power of this approach, we explored ectopic expression of a Wnt ligand in the mouse intestinal mesenchyme and demonstrate its functional influence on the adjacent epithelium. Our findings highlight the efficient use of lentiviral-mediated transgene expression for modulating mesenchymal-epithelial interactions in vivo.

  19. Lentiviral-Mediated Transgene Expression Can Potentiate Intestinal Mesenchymal-Epithelial Signaling

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    Kohn Aimee

    2009-01-01

    Full Text Available Abstract Mesenchymal-epithelial signaling is essential for the development of many organs and is often disrupted in disease. In this study, we demonstrate the use of lentiviral-mediated transgene delivery as an effective approach for ectopic transgene expression and an alternative to generation of transgenic animals. One benefit to this approach is that it can be used independently or in conjunction with established transgenic or knockout animals for studying modulation of mesenchymal-epithelial interactions. To display the power of this approach, we explored ectopic expression of a Wnt ligand in the mouse intestinal mesenchyme and demonstrate its functional influence on the adjacent epithelium. Our findings highlight the efficient use of lentiviral-mediated transgene expression for modulating mesenchymal-epithelial interactions in vivo.

  20. Transmigration route of Campylobacter jejuni across polarized intestinal epithelial cells: paracellular, transcellular or both?

    Science.gov (United States)

    2013-01-01

    Intact intercellular junctions and cellular matrix contacts are crucial structural components for the formation and maintenance of epithelial barrier functions in humans to control the commensal flora and protect against intruding microbes. Campylobacter jejuni is one of the most important zoonotic pathogens causing food-borne gastroenteritis and potentially more severe diseases such as reactive arthritis or Guillain–Barré syndrome. Crossing the intestinal epithelial barrier and host cell invasion by C. jejuni are considered to represent the primary reasons of gut tissue damage in humans and various animal model systems including monkeys, piglets, rabbits, hamsters and ferrets. C. jejuni is also able to invade underlying tissues such as the lamina propria, can enter the bloodstream, and possibly reach distinct organs such as spleen, liver or mesenteric lymph nodes. However, the molecular mechanisms as well as major bacterial and host cell factors involved in these activities are poorly understood. Various models exist by which the pathogen can trigger its own transmigration across polarized intestinal epithelial cells in vitro, the paracellular and/or transcellular mechanism. Recent studies suggest that bacterial factors such as flagellum, serine protease HtrA and lipooligosaccharide LOS may play an active role in bacterial transmigration. Here we review our knowledge on transmigration of C. jejuni as well as some other Campylobacter species, and discuss the pros and cons for the route(s) taken to travel across polarized epithelial cell monolayers. These studies provide fresh insights into the infection strategies employed by this important pathogen. PMID:24079544

  1. The uptake of soluble and particulate antigens by epithelial cells in the mouse small intestine.

    Science.gov (United States)

    Howe, Savannah E; Lickteig, Duane J; Plunkett, Kyle N; Ryerse, Jan S; Konjufca, Vjollca

    2014-01-01

    Intestinal epithelial cells (IECs) overlying the villi play a prominent role in absorption of digested nutrients and establish a barrier that separates the internal milieu from potentially harmful microbial antigens. Several mechanisms by which antigens of dietary and microbial origin enter the body have been identified; however whether IECs play a role in antigen uptake is not known. Using in vivo imaging of the mouse small intestine, we investigated whether epithelial cells (enterocytes) play an active role in the uptake (sampling) of lumen antigens. We found that small molecular weight antigens such as chicken ovalbumin, dextran, and bacterial LPS enter the lamina propria, the loose connective tissue which lies beneath the epithelium via goblet cell associated passageways. However, epithelial cells overlying the villi can internalize particulate antigens such as bacterial cell debris and inert nanoparticles (NPs), which are then found co-localizing with the CD11c+ dendritic cells in the lamina propria. The extent of NP uptake by IECs depends on their size: 20-40 nm NPs are taken up readily, while NPs larger than 100 nm are taken up mainly by the epithelial cells overlying Peyer's patches. Blocking NPs with small proteins or conjugating them with ovalbumin does not inhibit their uptake. However, the uptake of 40 nm NPs can be inhibited when they are administered with an endocytosis inhibitor (chlorpromazine). Delineating the mechanisms of antigen uptake in the gut is essential for understanding how tolerance and immunity to lumen antigens are generated, and for the development of mucosal vaccines and therapies.

  2. The suppressor of cytokine signaling SOCS1 promotes apoptosis of intestinal epithelial cells via p53 signaling in Crohn's disease.

    Science.gov (United States)

    Cui, Xiaopeng; Shan, Xiaohang; Qian, Ji; Ji, Qianqian; Wang, Liang; Wang, Xiaotong; Li, Manhua; Ding, Haifang; Liu, Qingqing; Chen, Lingling; Zhang, Dongmei; Ni, Runzhou

    2016-08-01

    The suppressor of cytokine signaling SOCS1 is a member of the cytokine signaling pathway inhibitor family, which is induced by the IFN-γ induced JAK signaling pathway. The expression of SOCS1 has been found to increase in Crohn's disease (CD) patients, but the role of SOCS1 in intestinal epithelium is unclear. This study was designed to investigate whether SOCS1 has a role in the death of intestinal epithelial cells and intestinal injury. The results showed that the expression of SOCS1 increased in CD patients, and the expression of SOCS1, p-p53 and PUMA increased in the mouse TNBS induced colitis model. Using IFN-γ treated HT-29 cells as an apoptotic model of intestinal epithelial cells in vitro, we confirmed that SOCS1 promoted apoptosis of intestinal epithelial cells by activating p53. In HT-29 cells which were treated with IFN-γ, the interaction between p53 and SOCS1 and phosphorylation of p53 were significantly higher than untreated cells. When knocking SOCS1 down by using SOCS1 siRNA, phosphorylation of p53 and apoptosis of intestinal epithelial cells which was induced by IFN-γ were significantly inhibited. In summary, our findings suggest that SOCS1 may promote apoptosis of intestinal epithelial cells at least partly through mediating p53 signaling.

  3. Hot spices influence permeability of human intestinal epithelial monolayers.

    Science.gov (United States)

    Jensen-Jarolim, E; Gajdzik, L; Haberl, I; Kraft, D; Scheiner, O; Graf, J

    1998-03-01

    Indirect evidence suggests that hot spices may interact with epithelial cells of the gastrointestinal tract to modulate their transport properties. Using HCT-8 cells, a cell line from a human ileocoecal carcinoma, we studied the effects of spices on transepithelial electrical resistance (TER), permeability for fluorescein isothiocyanate (FITC)-labeled dextrans with graded molecular weight, and morphological alterations of tight junctions by immunofluorescence using an anti-ZO-1 antibody, a marker for tight junction integrity. Two different reactivity patterns were observed: paprika and cayenne pepper significantly decreased the TER and increased permeability for 10-, 20- and 40-kDa dextrans but not for -70 kDa dextrans. Simultaneously, tight junctions exhibited a discontinuous pattern. Applying extracts from black or green pepper, bay leaf or nutmeg increased the TER and macromolecular permeability remained low. Immunofluorescence ZO-1 staining was preserved. In accordance with the above findings, capsaicin transiently reduced resistance and piperine increased resistance, making them candidates for causing the effects seen with crude spice extracts. The observation that Solanaceae spices (paprika, cayenne pepper) increase permeability for ions and macromolecules might be of pathophysiological importance, particularly with respect to food allergy and intolerance.

  4. Salmonella typhimurium infection increases p53 acetylation in intestinal epithelial cells.

    Science.gov (United States)

    Wu, Shaoping; Ye, Zhongde; Liu, Xingyin; Zhao, Yun; Xia, Yinglin; Steiner, Andrew; Petrof, Elaine O; Claud, Erika C; Sun, Jun

    2010-05-01

    The ability of Salmonella typhimurium to enter intestinal epithelial cells constitutes a crucial step in pathogenesis. Salmonella invasion of the intestinal epithelium requires bacterial type three secretion system. Type three secretion system is a transport device that injects virulence proteins, called effectors, to paralyze or reprogram the eukaryotic cells. Avirulence factor for Salmonella (AvrA) is a Salmonella effector that inhibits the host's inflammatory responses. The mechanism by which AvrA modulates host cell signaling is not entirely clear. p53 is situated at the crossroads of a network of signaling pathways that are essential for genotoxic and nongenotoxic stress responses. We hypothesized that Salmonella infection activates the p53 pathway. We demonstrated that Salmonella infection increased p53 acetylation. Cells infected with AvrA-sufficient Salmonella have increased p53 acetylation, whereas cells infected with AvrA-deficient Salmonella have less p53 acetylation. In a cell-free system, AvrA possessed acetyltransferase activity and used p53 as a substrate. AvrA expression increased p53 transcriptional activity and induced cell cycle arrest. HCT116 p53-/- cells had less inflammatory responses. In a mouse model of Salmonella infection, intestinal epithelial p53 acetylation was increased by AvrA expression. Our studies provide novel mechanistic evidence that Salmonella modulates the p53 pathway during intestinal inflammation and infection.

  5. Physiological significance of taurine and the taurine transporter in intestinal epithelial cells.

    Science.gov (United States)

    Shimizu, M; Satsu, H

    2000-01-01

    Taurine transport in human intestinal epithelial Caco-2 cells was down-regulated by culturing the cells in taurine-containing media and was up-regulated in a taurine-free medium. This adaptive regulation was associated with changes in both the Vmax and Km values of taurine transport. A change in the mRNA level of the taurine transporter (TAUT) in this regulation was also observed. The presence of such a regulatory mechanism for maintaining the intracellular taurine content at a certain level suggests that taurine plays an important role in the intestinal cell functions. The intracellular taurine content was increased when Caco-2 cells were exposed to a hypertonic stress. TAUT was up-regulated via the increased expression of TAUT mRNA in the hypertonic cells, suggesting that taurine serves as an osmolyte and protects the cells from osmotic stress. Similar up-regulation of TAUT was observed in the small intestine of water-deprived rats.

  6. Heme in intestinal epithelial cell turnover, differentiation,detoxification, inflammation, carcinogenesis, absorption and motility

    Institute of Scientific and Technical Information of China (English)

    Phillip S Oates; Adrian R West

    2006-01-01

    The gastrointestinal tract is lined by a simple epithelium that undergoes constant renewal involving cell division,differentiation and cell death. In addition, the epithelial lining separates the hostile processes of digestion and absorption that occur in the intestinal lumen from the aseptic environment of the internal milieu by defensive mechanisms that protect the epithelium from being breached. Central to these defensive processes is the synthesis of heme and its catabolism by heme oxygenase (HO). Dietary heme is also an important source of iron for the body which is taken up intact by the enterocyte.This review describes the recent literature on the diverse properties of heme/HO in the intestine tract.The roles of heme/HO in the regulation of the cell cycle/apoptosis, detoxification of xenobiotics, oxidative stress,inflammation, development of colon cancer, hemeiron absorption and intestinal motility are specifically examined.

  7. Cell dedifferentiation and epithelial to mesenchymal transitions during intestinal regeneration in H. glaberrima

    Directory of Open Access Journals (Sweden)

    Rivera-Cruz Angélica

    2011-10-01

    Full Text Available Abstract Background Determining the type and source of cells involved in regenerative processes has been one of the most important goals of researchers in the field of regeneration biology. We have previously used several cellular markers to characterize the cells involved in the regeneration of the intestine in the sea cucumber Holothuria glaberrima. Results We have now obtained a monoclonal antibody that labels the mesothelium; the outer layer of the gut wall composed of peritoneocytes and myocytes. Using this antibody we studied the role of this tissue layer in the early stages of intestinal regeneration. We have now shown that the mesothelial cells of the mesentery, specifically the muscle component, undergo dedifferentiation from very early on in the regeneration process. Cell proliferation, on the other hand, increases much later, and mainly takes place in the mesothelium or coelomic epithelium of the regenerating intestinal rudiment. Moreover, we have found that the formation of the intestinal rudiment involves a novel regenerative mechanism where epithelial cells ingress into the connective tissue and acquire mesenchymal phenotypes. Conclusions Our results strongly suggest that the dedifferentiating mesothelium provides the initial source of cells for the formation of the intestinal rudiment. At later stages, cell proliferation supplies additional cells necessary for the increase in size of the regenerate. Our data also shows that the mechanism of epithelial to mesenchymal transition provides many of the connective tissue cells found in the regenerating intestine. These results present some new and important information as to the cellular basis of organ regeneration and in particular to the process of regeneration of visceral organs.

  8. Characteristic Changes in Cell Surface Glycosylation Accompany Intestinal Epithelial Cell (IEC) Differentiation: High Mannose Structures Dominate the Cell Surface Glycome of Undifferentiated Enterocytes.

    Science.gov (United States)

    Park, Dayoung; Brune, Kristin A; Mitra, Anupam; Marusina, Alina I; Maverakis, Emanual; Lebrilla, Carlito B

    2015-11-01

    Changes in cell surface glycosylation occur during the development and differentiation of cells and have been widely correlated with the progression of several diseases. Because of their structural diversity and sensitivity to intra- and extracellular conditions, glycans are an indispensable tool for analyzing cellular transformations. Glycans present on the surface of intestinal epithelial cells (IEC) mediate interactions with billions of native microorganisms, which continuously populate the mammalian gut. A distinct feature of IECs is that they differentiate as they migrate upwards from the crypt base to the villus tip. In this study, nano-LC/ESI QTOF MS profiling was used to characterize the changes in glycosylation that correspond to Caco-2 cell differentiation. As Caco-2 cells differentiate to form a brush border membrane, a decrease in high mannose type glycans and a concurrent increase in fucosylated and sialylated complex/hybrid type glycans were observed. At day 21, when cells appear to be completely differentiated, remodeling of the cell surface glycome ceases. Differential expression of glycans during IEC maturation appears to play a key functional role in regulating the membrane-associated hydrolases and contributes to the mucosal surface innate defense mechanisms. Developing methodologies to rapidly identify changes in IEC surface glycans may lead to a rapid screening approach for a variety of disease states affecting the GI tract. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  9. Campylobacter-induced interleukin-8 responses in human intestinal epithelial cells and primary intestinal chick cells.

    Science.gov (United States)

    Borrmann, Erika; Berndt, Angela; Hänel, Ingrid; Köhler, Heike

    2007-09-20

    Campylobacter (C.) jejuni and C. coli can cause gastrointestinal disorders in humans characterized by acute inflammation. Inflammatory signals are initiated during interaction between these pathogens and human intestinal cells, but nothing is known about the stimulation of avian intestinal cells by Campylobacter. Interleukin-8 (IL-8) as a proinflammatory chemokine plays an important role in mobilizing cellular defence mechanism. IL-8 mRNA expression in both human intestinal cells (INT 407) and primary intestinal chick cells (PIC) was determined by quantitative real-time RT-PCR. The secretion of IL-8 protein by INT407 was measured using ELISA. Although C. jejuni and C. coli are considered to be harmless commensals in the gut of birds, the avian Campylobacter isolates investigated were able to induce the proinflammatory IL-8 in PIC as well as in INT407. In an in vitro system, C. jejuni as well as C. coli were able to induce IL-8 mRNA in PIC. Relation between the virulence properties like toxin production, the ability to invade and to survive in Caco-2 cells and the level of IL-8 mRNA produced by INT 407 and PIC after infection with Campylobacter strains was also investigated.

  10. A Three-Dimensional Cell Culture Model To Study Enterovirus Infection of Polarized Intestinal Epithelial Cells.

    Science.gov (United States)

    Drummond, Coyne G; Nickerson, Cheryl A; Coyne, Carolyn B

    2016-01-01

    Despite serving as the primary entry portal for coxsackievirus B (CVB), little is known about CVB infection of the intestinal epithelium, owing at least in part to the lack of suitable in vivo models and the inability of cultured cells to recapitulate the complexity and structure associated with the gastrointestinal (GI) tract. Here, we report on the development of a three-dimensional (3-D) organotypic cell culture model of Caco-2 cells to model CVB infection of the gastrointestinal epithelium. We show that Caco-2 cells grown in 3-D using the rotating wall vessel (RWV) bioreactor recapitulate many of the properties of the intestinal epithelium, including the formation of well-developed tight junctions, apical-basolateral polarity, brush borders, and multicellular complexity. In addition, transcriptome analyses using transcriptome sequencing (RNA-Seq) revealed the induction of a number of genes associated with intestinal epithelial differentiation and/or intestinal processes in vivo when Caco-2 cells were cultured in 3-D. Applying this model to CVB infection, we found that although the levels of intracellular virus production were similar in two-dimensional (2-D) and 3-D Caco-2 cell cultures, the release of infectious CVB was enhanced in 3-D cultures at early stages of infection. Unlike CVB, the replication of poliovirus (PV) was significantly reduced in 3-D Caco-2 cell cultures. Collectively, our studies show that Caco-2 cells grown in 3-D using the RWV bioreactor provide a cell culture model that structurally and transcriptionally represents key aspects of cells in the human GI tract and can thus be used to expand our understanding of enterovirus-host interactions in intestinal epithelial cells. IMPORTANCE Coxsackievirus B (CVB), a member of the enterovirus family of RNA viruses, is associated with meningitis, pericarditis, diabetes, dilated cardiomyopathy, and myocarditis, among other pathologies. CVB is transmitted via the fecal-oral route and encounters the

  11. Protective effects of alanyl-glutamine supplementation against nelfinavir-induced epithelial impairment in IEC-6 cells and in mouse intestinal mucosa.

    Science.gov (United States)

    Braga-Neto, Manuel B; Oliveira, Bruna M C; Rodrigues, Raphael S; Noronha, Francisco J; Leitao, Renata F; Brito, Gerly A C; Lima, Aldo A; Guerrant, Richard L; Warren, Cirle A

    2012-12-01

    Human Immunodeficiency Virus (HIV) protease inhibitors (PI) remain a crucial component of highly active therapy (HAART) and recently have been demonstrated to have potent antitumor effect on a wide variety of tumor cell lines. However, discontinuation of therapy is an important issue, which may be related to various side-effects, especially diarrhea. The aim of this study was to evaluate the effects of nelfinavir (NFV), an HIV PI, and of alanyl-glutamine (AQ) supplementation, on intestinal cell migration, proliferation, apoptosis and necrosis, using IEC-6 cells and on intestinal crypt depth, villus length, villus area, mitotic index and apoptosis in Swiss mice. Migration was evaluated at 12 and 24 h after injury using a wound healing assay. Cellular proliferation was measured indirectly at 24 and 48 h using tetrazolium salt WST-1. Apoptosis and necrosis were measured by flow cytometry using the Annexin V assay. Intestinal morphometry and mitotic index in vivo were assessed following a seven-day treatment with 100 mg/kg of NFV, given orally. In vivo proliferation and apoptosis were evaluated by intestinal crypt mitotic index and immunohistochemistry, respectively. In vitro, AQ supplementation enhanced IEC-6 cell migration and proliferation, following challenge with NFV. In vivo, AQ increased intestinal villus length, villus area, crypt depth and cell proliferation and cell migration, following treatment with NFV. AQ did not decrease cell death induced by NFV both in vivo and in vitro. AQ supplementation is potentially beneficial in preventing the effects of PIs, such as NFV, in the intestinal tract.

  12. Histological alterations of intestinal villi and epithelial cells after feeding dietary sugar cane extract in piglets

    Directory of Open Access Journals (Sweden)

    Toshikazu Kawai

    2012-07-01

    Full Text Available Effects of sugar cane extract (SCE on the piglet intestinal histology were observed. Twelve castrated male piglets weaned at the age of 26 days were allotted to three groups fed diets containing 0, 0.05 or 0.10% SCE. At the end of feeding experiment, each intestinal segment was taken for light or scanning electron microscopy. Feed intake, body weight gain and feed efficiency did not show a difference among groups. Most of the values for villus height, villus area, cell area and cell mitosis numbers were not different among groups, except for that the villus area of the 0.10% SCE group and the cell area of both SCE groups increased significantly at the jejunum compared to the control (P<0.05. For cell mitosis numbers, the 0.10% SCE group was higher than the 0.05% SCE group at the jejunum. Compared with the majority of flat cells of each intestinal segment in the control, the SCE groups had protuberated cells. In the 0.05% SCE group, deeper cells at the sites of recently exfoliated cells in the duodenum, cell clusters aggregated by protuberated cells in the jejunum and much more protuberant cells in the ileum were observed. These histological intestinal alterations suggest that SCE could raise the functions of intestinal villi and epithelial cells, especially at the 0.05%.

  13. Lactobacillus gasseri SF1183 affects intestinal epithelial cell survival and growth.

    Directory of Open Access Journals (Sweden)

    Blanda Di Luccia

    Full Text Available It is now commonly accepted that the intestinal microbiota plays a crucial role in the gut physiology and homeostasis, and that both qualitative and quantitative alterations in the compositions of the gut flora exert profound effects on the host's intestinal cells. In spite of this, the details of the interaction between commensal bacteria and intestinal cells are still largely unknown and only in few cases the molecular mechanisms have been elucidated. Here we analyze the effects of molecules produced and secreted by Lactobacillus gasseri SF1183 on human intestinal HCT116 cells. L. gasseri is a well known species of lactic acid bacteria, commonly associated to the human intestine and SF1183 is a human strain previously isolated from an ileal biopsy of an healthy volunteer. SF1183 produces and secretes, in a growth phase-dependent way, molecule(s able to drastically interfere with HCT116 cell proliferation. Although several attempts to purify and identify the bioactive molecule(s have been so far unsuccessful, a partial characterization has indicated that it is smaller than 3 kDa, thermostable and of proteinaceous nature. L. gasseri molecule(s stimulate a G1-phase arrest of the cell cycle by up-regulation of p21WAF1 rendering cells protected from intrinsic and extrinsic apoptosis. A L. gasseri-mediated reduction of apoptosis and of cell proliferation could be relevant in protecting epithelial barrier integrity and helping in reconstituting tissutal homeostasis.

  14. Arginine Consumption by the Intestinal Parasite Giardia intestinalis Reduces Proliferation of Intestinal Epithelial Cells

    OpenAIRE

    Britta Stadelmann; Merino, María C.; Lo Persson; Staffan G Svärd

    2012-01-01

    In the field of infectious diseases the multifaceted amino acid arginine has reached special attention as substrate for the host´s production of the antimicrobial agent nitric oxide (NO). A variety of infectious organisms interfere with this part of the host immune response by reducing the availability of arginine. This prompted us to further investigate additional roles of arginine during pathogen infections. As a model we used the intestinal parasite Giardia intestinalis that actively consu...

  15. Heat shock protein 70-dependent protective effect of polaprezinc on acetylsalicylic acid-induced apoptosis of rat intestinal epithelial cells.

    Science.gov (United States)

    Qin, Ying; Naito, Yuji; Handa, Osamu; Hayashi, Natsuko; Kuki, Aiko; Mizushima, Katsura; Omatsu, Tatsushi; Tanimura, Yuko; Morita, Mayuko; Adachi, Satoko; Fukui, Akifumi; Hirata, Ikuhiro; Kishimoto, Etsuko; Nishikawa, Taichiro; Uchiyama, Kazuhiko; Ishikawa, Takeshi; Takagi, Tomohisa; Yagi, Nobuaki; Kokura, Satoshi; Yoshikawa, Toshikazu

    2011-11-01

    Protection of the small intestine from mucosal injury induced by nonsteroidal anti-inflammatory drugs including acetylsalicylic acid is a critical issue in the field of gastroenterology. Polaprezinc an anti-ulcer drug, consisting of zinc and L-carnosine, provides gastric mucosal protection against various irritants. In this study, we investigated the protective effect of polaprezinc on acetylsalicylic acid-induced apoptosis of the RIE1 rat intestinal epithelial cell line. Confluent rat intestinal epithelial cells were incubated with 70 µM polaprezinc for 24 h, and then stimulated with or without 15 mM acetylsalicylic acid for a further 15 h. Subsequent cellular viability was quantified by fluorometric assay based on cell lysis and staining. Acetylsalicylic acid-induced cell death was also qualified by fluorescent microscopy of Hoechst33342 and propidium iodide. Heat shock proteins 70 protein expression after adding polaprezinc or acetylsalicylic acid was assessed by western blotting. To investigate the role of Heat shock protein 70, Heat shock protein 70-specific small interfering RNA was applied. Cell viability was quantified by fluorometric assay based on cell lysis and staining and apoptosis was analyzed by fluorescence-activated cell sorting. We found that acetylsalicylic acid significantly induced apoptosis of rat intestinal epithelial cells in a dose- and time-dependent manner. Polaprezinc significantly suppressed acetylsalicylic acid-induced apoptosis of rat intestinal epithelial cells at its late phase. At the same time, polaprezinc increased Heat shock protein 70 expressions of rat intestinal epithelial cells in a time-dependent manner. However, in Heat shock protein 70-silenced rat intestinal epithelial cells, polaprezinc could not suppress acetylsalicylic acid -induced apoptosis at its late phase. We conclude that polaprezinc-increased Heat shock protein 70 expression might be an important mechanism by which polaprezinc suppresses acetylsalicylic

  16. Cross-talk between intestinal epithelial cells and immune cells in inflammatory bowel disease.

    Science.gov (United States)

    Al-Ghadban, Sara; Kaissi, Samira; Homaidan, Fadia R; Naim, Hassan Y; El-Sabban, Marwan E

    2016-07-15

    Inflammatory bowel disease (IBD) involves functional impairment of intestinal epithelial cells (IECs), concomitant with the infiltration of the lamina propria by inflammatory cells. We explored the reciprocal paracrine and direct interaction between human IECs and macrophages (MΦ) in a co-culture system that mimics some aspects of IBD. We investigated the expression of intercellular junctional proteins in cultured IECs under inflammatory conditions and in tissues from IBD patients. IECs establish functional gap junctions with IECs and MΦ, respectively. Connexin (Cx26) and Cx43 expression in cultured IECs is augmented under inflammatory conditions; while, Cx43-associated junctional complexes partners, E-cadherin, ZO-1, and β-catenin expression is decreased. The expression of Cx26 and Cx43 in IBD tissues is redistributed to the basal membrane of IEC, which is associated with decrease in junctional complex proteins' expression, collagen type IV expression and infiltration of MΦ. These data support the notion that the combination of paracrine and hetero-cellular communication between IECs and MΦs may regulate epithelial cell function through the establishment of junctional complexes between inflammatory cells and IECs, which ultimately contribute to the dys-regulation of intestinal epithelial barrier.

  17. Disruption of the epithelial barrier during intestinal inflammation: Quest for new molecules and mechanisms.

    Science.gov (United States)

    Lechuga, Susana; Ivanov, Andrei I

    2017-03-16

    The intestinal epithelium forms a key protective barrier that separates internal organs from the harmful environment of the gut lumen. Increased permeability of the gut barrier is a common manifestation of different inflammatory disorders contributing to the severity of disease. Barrier permeability is controlled by epithelial adherens junctions and tight junctions. Junctional assembly and integrity depend on fundamental homeostatic processes such as cell differentiation, rearrangements of the cytoskeleton, and vesicle trafficking. Alterations of intestinal epithelial homeostasis during mucosal inflammation may impair structure and remodeling of apical junctions, resulting in increased permeability of the gut barrier. In this review, we summarize recent advances in our understanding of how altered epithelial homeostasis affects the structure and function of adherens junctions and tight junctions in the inflamed gut. Specifically, we focus on the transcription reprogramming of the cell, alterations in the actin cytoskeleton, and junctional endocytosis and exocytosis. We pay special attention to knockout mouse model studies and discuss the relevance of these mechanisms to human gastrointestinal disorders.

  18. Cross-talk between intestinal epithelial cells and immune cells in inflammatory bowel disease

    Science.gov (United States)

    Al-Ghadban, Sara; Kaissi, Samira; Homaidan, Fadia R.; Naim, Hassan Y.; El-Sabban, Marwan E.

    2016-01-01

    Inflammatory bowel disease (IBD) involves functional impairment of intestinal epithelial cells (IECs), concomitant with the infiltration of the lamina propria by inflammatory cells. We explored the reciprocal paracrine and direct interaction between human IECs and macrophages (MΦ) in a co-culture system that mimics some aspects of IBD. We investigated the expression of intercellular junctional proteins in cultured IECs under inflammatory conditions and in tissues from IBD patients. IECs establish functional gap junctions with IECs and MΦ, respectively. Connexin (Cx26) and Cx43 expression in cultured IECs is augmented under inflammatory conditions; while, Cx43-associated junctional complexes partners, E-cadherin, ZO-1, and β-catenin expression is decreased. The expression of Cx26 and Cx43 in IBD tissues is redistributed to the basal membrane of IEC, which is associated with decrease in junctional complex proteins’ expression, collagen type IV expression and infiltration of MΦ. These data support the notion that the combination of paracrine and hetero-cellular communication between IECs and MΦs may regulate epithelial cell function through the establishment of junctional complexes between inflammatory cells and IECs, which ultimately contribute to the dys-regulation of intestinal epithelial barrier. PMID:27417573

  19. Enterocyte shedding and epithelial lining repair following ischemia of the human small intestine attenuate inflammation.

    Science.gov (United States)

    Matthijsen, Robert A; Derikx, Joep P M; Kuipers, Dian; van Dam, Ronald M; Dejong, Cornelis H C; Buurman, Wim A

    2009-09-15

    Recently, we observed that small-intestinal ischemia and reperfusion was found to entail a rapid loss of apoptotic and necrotic cells. This study was conducted to investigate whether the observed shedding of ischemically damaged epithelial cells affects IR induced inflammation in the human small gut. Using a newly developed IR model of the human small intestine, the inflammatory response was studied on cellular, protein and mRNA level. Thirty patients were consecutively included. Part of the jejunum was subjected to 30 minutes of ischemia and variable reperfusion periods (mean reperfusion time 120 (+/-11) minutes). Ethical approval and informed consent were obtained. Increased plasma intestinal fatty acid binding protein (I-FABP) levels indicated loss in epithelial cell integrity in response to ischemia and reperfusion (pintestine, thirty minutes of ischemia followed by up to 4 hours of reperfusion, does not seem to lead to an explicit inflammatory response. This may be explained by a unique mechanism of shedding of damaged enterocytes, reported for the first time by our group.

  20. 2-DE and MS analysis of interactions between Lactobacillus fermentum I5007 and intestinal epithelial cells.

    Science.gov (United States)

    Yang, Fang; Wang, Junjun; Li, Xiaojie; Ying, Tianyi; Qiao, Shiyan; Li, Defa; Wu, Guoyao

    2007-12-01

    Lactobacillus is a probiotic commonly used for supplementation to human and animal diets. In this study, we used 2-DE and MS to analyze changes in the proteomes of Lactobacillus and intestinal epithelial cells in two model systems. The in vivo and in vitro models were involved the inoculation of Lactobacillus fermentum I5007 into the rabbit jejunum for 4 h and the culture of the bacterium with Caco-2 cells for 1 h, respectively. Our results indicate that, after exposure to the intestinal environment, the bacterium exhibited decreases in key enzymes involved in energy metabolism (e.g., lactate dehydrogenase, dihydrolipoamide dehydrogenase, and nicotinate phosphoribosyltransferase) and amino acid metabolism (e.g., arginyl-tRNA synthetase and aspartate-semialdehyde dehydrogenase), but increases in glycoside hydrolase (an enzyme for mucin degradation) and fructose-6-phosphate phosphoketolase (an enzyme of the pentose phosphate pathway). In response to an interaction with L. fermentum I5007, Caco-2 cells showed changes in proteins that were beneficial for gut integrity, including voltage-dependent anion channel 1, glutathione transferase, and heat shock protein gp96. On the basis of their functions, we suggest that these proteins serve as useful biomarkers for metabolic changes in Lactobacillus and intestinal epithelial cells in response to their interactions.

  1. TLR-independent anti-inflammatory function of intestinal epithelial TRAF6 signalling prevents DSS-induced colitis in mice.

    Science.gov (United States)

    Vlantis, Katerina; Polykratis, Apostolos; Welz, Patrick-Simon; van Loo, Geert; Pasparakis, Manolis; Wullaert, Andy

    2016-06-01

    The gut microbiota modulates host susceptibility to intestinal inflammation, but the cell types and the signalling pathways orchestrating this bacterial regulation of intestinal homeostasis remain poorly understood. Here, we investigated the function of intestinal epithelial toll-like receptor (TLR) responses in the dextran sodium sulfate (DSS)-induced mouse model of colitis. We applied an in vivo genetic approach allowing intestinal epithelial cell (IEC)-specific deletion of the critical TLR signalling adaptors, MyD88 and/or TIR-domain-containing adapter-inducing interferon-β (TRIF), as well as the downstream ubiquitin ligase TRAF6 in order to reveal the IEC-intrinsic function of these TLR signalling molecules during DSS colitis. Mice lacking TRAF6 in IECs showed exacerbated DSS-induced inflammatory responses that ensued in the development of chronic colon inflammation. Antibiotic pretreatment abolished the increased DSS susceptibility of these mice, showing that epithelial TRAF6 signalling pathways prevent the gut microbiota from driving excessive colitis. However, in contrast to epithelial TRAF6 deletion, blocking epithelial TLR signalling by simultaneous deletion of MyD88 and TRIF specifically in IECs did not affect DSS-induced colitis severity. This in vivo functional comparison between TRAF6 and MyD88/TRIF deletion in IECs shows that the colitis-protecting effects of epithelial TRAF6 signalling are not triggered by TLRs. Intestinal epithelial TRAF6-dependent but MyD88/TRIF-independent and, thus, TLR-independent signalling pathways are critical for preventing propagation of DSS-induced colon inflammation by the gut microbiota. Moreover, our experiments using mice with dual MyD88/TRIF deletion in IECs unequivocally show that the gut microbiota trigger non-epithelial TLRs rather than epithelial TLRs to restrict DSS colitis severity. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  2. Patterns of proliferative activity in the colonic crypt determine crypt stability and rates of somatic evolution.

    Directory of Open Access Journals (Sweden)

    Rui Zhao

    Full Text Available Epithelial cells in the colon are arranged in cylindrical structures called crypts in which cellular proliferation and migration are tightly regulated. We hypothesized that the proliferation patterns of cells may determine the stability of crypts as well as the rates of somatic evolution towards colorectal tumorigenesis. Here, we propose a linear process model of colonic epithelial cells that explicitly takes into account the proliferation kinetics of cells as a function of cell position within the crypt. Our results indicate that proliferation kinetics has significant influence on the speed of cell movement, kinetics of mutation propagation, and sensitivity of the system to selective effects of mutated cells. We found that, of all proliferation curves tested, those with mitotic activities concentrated near the stem cell, including the actual proliferation kinetics determined in in vivo labeling experiments, have a greater ability of delaying the rate of mutation accumulation in colonic stem cells compared to hypothetical proliferation curves with mitotic activities focused near the top of the crypt column. Our model can be used to investigate the dynamics of proliferation and mutation accumulation in spatially arranged tissues.

  3. Effect of fat feeding on pro-oxidant and anti-oxidant enzyme systems in rat intestine: possible role in the turnover of enterocytes.

    Science.gov (United States)

    Turan, Aasma; Gill, Ravinder; Dudeja, Pradeep K; Mohan, Harsh; Mahmood, Akhtar

    2009-06-01

    Immature epithelial cells generated in the crypt base undergo differentiation while progressing to the villus tip, where the cells upon apoptosis are detached from the underlying muscular tissue. We previously reported that lipid peroxidation might be involved in the turnover of enterocytes across the crypt-villus axis in rat intestine (Dig Dis Sci 52:1840-1844, 2007). To examine whether long-term feeding of fat with different fatty-acid composition influences this process, in the present study we investigated the effect of feeding fish oil (n - 3) and corn oil (n - 6) polyunsaturated fatty acids on lipid per-oxidation and anti-oxidant systems in different epithelial cell fractions isolated in rat intestine. Feeding fish oil or corn oil markedly enhanced lipid per-oxidation levels of enterocytes throughout villus height compared with control, but there was no difference in the distribution profile of pro- and anti-oxidant enzyme systems and lipid per-oxidation across the crypt-villus axis under these conditions. Analysis of lipid peroxidation levels in different cell fractions revealed that the thiobarbituric acid reactive substance were 9- to 11-fold higher at the villus tip compared with at the crypt base. The activities of glutathione reductase and glutathione-S-transferase were 2- to 5-fold higher in villus tip compared to the crypt region. However, the activities of superoxide dismutase and catalase were 6- to 8-fold high at the crypt base compared with at villus tip cells. Immunocytolocalization of superoxide dismutase showed high staining in crypt base compared with that in villus, tip cells. These findings further suggest that generation of reactive oxygen species in enterocytes across the crypt-villus axis may be involved in turnover of enterocytes across the crypt-villus unit in rat intestine.

  4. Free fucose is a danger signal to human intestinal epithelial cells.

    Science.gov (United States)

    Chow, Wai Ling; Lee, Yuan Kun

    2008-03-01

    Fucose is present in foods, and it is a major component of human mucin glycoproteins and glycolipids. l-Fucose can also be found at the terminal position of many cell-surface oligosaccharide ligands that mediate cell-recognition and adhesion-signalling pathways. Mucin fucose can be released through the hydrolytic activity of pathogens and indigenous bacteria, leading to the release of free fucose into the intestinal lumen. The immunomodulating effects of free fucose on intestinal epithelial cells (enterocyte-like Caco-2) were investigated. It was found that the presence of l-fucose up regulated genes and secretion of their encoded proteins that are involved in both the innate and adaptive immune responses, possibly via the toll-like receptor-2 signalling pathway. These include TNFSF5, TNFSF7, TNF-alpha, IL12, IL17 and IL18. Besides modulating immune reactions in differentiated Caco-2 cells, fucose induced a set of cytokine genes that are involved in the development and proliferation of immune cells. These include the bone morphogenetic proteins (BMP) BMP2, BMP4, IL5, thrombopoietin and erythropoietin. In addition, the up regulated gene expression of fibroblast growth factor-2 may help to promote epithelial cell restitution in conjunction with the enhanced expression of transforming growth factor-beta mRNA. Since the exogenous fucose was not metabolised by the differentiated Caco-2 cells as a carbon source, the reactions elicited were suggested to be a result of the direct interaction of fucose and differentiated Caco-2 cells. The presence of free fucose may signal the invasion of mucin-hydrolysing microbial cells and breakage of the mucosal barrier. The intestinal epithelial cells respond by up regulation and secretion of cytokines, pre-empting the actual invasion of pathogens.

  5. The Role of Probiotics in Lipopolysaccharide-Induced Autophagy in Intestinal Epithelial Cells.

    Science.gov (United States)

    Han, Chaoqun; Ding, Zhen; Shi, Huiying; Qian, Wei; Hou, Xiaohua; Lin, Rong

    2016-01-01

    Dysfunction of autophagy has been associated with loss of intestinal homeostasis. Lipopolysaccharide (LPS) from Gram-negative bacteria is known to be a major initiator of intestinal epithelial cell (IEC) autophagy. Although probiotics have been recognized to be involved in many therapeutic properties and participate in host defense responses, the molecular mechanisms by which probiotics exert these positive effects remain unknown. This study assessed the effect of probiotics on LPS-induced physical barrier dysfunction and the underlying mechanism of probiotic action in IECs with a focus on autophagy. A LPS-induced autophagic model was established in rat IEC18 cells wherein cells were treated with culture medium supernatants of Bifidobacteria following LPS intervention at indicated times. Autophagosomes in IEC18 cells were visualized by confocal microscopy after transfection with a tandem GFP-mCherry-LC3 construct and also by transmission electron microscopy. Autophagy-associated protein levels were analyzed by western blot and transepithelial electrical resistance (TEER) was measured using an epithelial voltohmmeter. Probiotic treatment could effectively inhibit LPS-induced autophagy, as evidenced by the decreased ratio of microtubule-associated light chain 3 (LC3)-II/LC3-I, fewer autophagic vacuoles, and reduced punctate distribution of GFP-mCherry-LC3. In addition, probiotics prevented chloroquine (CQ) inhibition of autophagic flux and autophagolysosomal fusion as indicated by a failure to recruit LAMP1 and cathepsin D to lysosomes. Interestingly, ATG16L1 knockdown did not inhibit the effect of probiotics on LPS-induced autophagy. Furthermore, the diminished barrier function could be prevented by probiotics. We provide evidence that autophagy mediation by probiotics may be involved in enteroprotection against LPS-induced intestinal epithelial toxicity, and could serve as a novel mechanism through which probiotics promote and maintain gut homeostasis. © 2016 The

  6. Rho-A prenylation and signaling link epithelial homeostasis to intestinal inflammation

    DEFF Research Database (Denmark)

    López-Posadas, Rocío; Becker, Christoph; Günther, Claudia

    2016-01-01

    the transcriptome of IECs from IBD patients using a genome-wide approach. We observed disease-specific alterations in IECs with markedly impaired Rho-A signaling in active IBD patients. Localization of epithelial Rho-A was shifted to the cytosol in IBDs, and inflammation was associated with suppressed Rho......-A activation due to reduced expression of the Rho-A prenylation enzyme geranylgeranyltransferase-I (GGTase-I). Functionally, we found that mice with conditional loss of Rhoa or the gene encoding GGTase-I, Pggt1b, in IECs exhibit spontaneous chronic intestinal inflammation with accumulation of granulocytes...... and CD4+ T cells. This phenotype was associated with cytoskeleton rearrangement and aberrant cell shedding, ultimately leading to loss of epithelial integrity and subsequent inflammation. These findings uncover deficient prenylation of Rho-A as a key player in the pathogenesis of IBDs. As therapeutic...

  7. Identification of multi-drug resistant Pseudomonas aeruginosa clinical isolates that are highly disruptive to the intestinal epithelial barrier

    Directory of Open Access Journals (Sweden)

    Shevchenko Olga

    2006-06-01

    Full Text Available Abstract Background Multi-drug resistant Pseudomonas aeruginosa nosocomial infections are increasingly recognized worldwide. In this study, we focused on the virulence of multi-drug resistant clinical strains P. aeruginosa against the intestinal epithelial barrier, since P. aeruginosa can cause lethal sepsis from within the intestinal tract of critically ill and immuno-compromised patients via mechanisms involving disruption of epithelial barrier function. Methods We screened consecutively isolated multi-drug resistant P. aeruginosa clinical strains for their ability to disrupt the integrity of human cultured intestinal epithelial cells (Caco-2 and correlated these finding to related virulence phenotypes such as adhesiveness, motility, biofilm formation, and cytotoxicity. Results Results demonstrated that the majority of the multi-drug resistant P. aeruginosa clinical strains were attenuated in their ability to disrupt the barrier function of cultured intestinal epithelial cells. Three distinct genotypes were found that displayed an extreme epithelial barrier-disrupting phenotype. These strains were characterized and found to harbor the exoU gene and to display high swimming motility and adhesiveness. Conclusion These data suggest that detailed phenotypic analysis of the behavior of multi-drug resistant P. aeruginosa against the intestinal epithelium has the potential to identify strains most likely to place patients at risk for lethal gut-derived sepsis. Surveillance of colonizing strains of P. aeruginosa in critically ill patients beyond antibiotic sensitivity is warranted.

  8. Morphine Attenuates Apically-Directed Cytokine Secretion from Intestinal Epithelial Cells in Response to Enteric Pathogens

    Directory of Open Access Journals (Sweden)

    Amanda J. Brosnahan

    2014-04-01

    Full Text Available Epithelial cells represent the first line of host immune defense at mucosal surfaces. Although opioids appear to increase host susceptibility to infection, no studies have examined opioid effects on epithelial immune functions. We tested the hypothesis that morphine alters vectorial cytokine secretion from intestinal epithelial cell (IPEC-J2 monolayers in response to enteropathogens. Both entero-adherent Escherichia coli O157:H7 and entero-invasive Salmonella enterica serovar Typhimurium increased apically-directed IL-6 secretion and bi-directional IL-8 secretion from epithelial monolayers, but only IL-6 secretion evoked by E. coli was reduced by morphine acting through a naloxone-sensitive mechanism. Moreover, the respective type 4 and 5 Toll-like receptor agonists, lipopolysaccharide and flagellin, increased IL-8 secretion from monolayers, which was also attenuated by morphine pretreatment. These results suggest that morphine decreases cytokine secretion and potentially phagocyte migration and activation directed towards the mucosal surface; actions that could increase host susceptibility to some enteric infections.

  9. An LGG-derived protein promotes IgA production through upregulation of APRIL expression in intestinal epithelial cells.

    Science.gov (United States)

    Wang, Y; Liu, L; Moore, D J; Shen, X; Peek, R M; Acra, S A; Li, H; Ren, X; Polk, D B; Yan, F

    2017-03-01

    p40, a Lactobacillus rhamnosus GG (LGG)-derived protein, transactivates epidermal growth factor receptor (EGFR) in intestinal epithelial cells, leading to amelioration of intestinal injury and inflammation. To elucidate mechanisms by which p40 regulates mucosal immunity to prevent inflammation, this study aimed to determine the effects and mechanisms of p40 on regulation of a proliferation-inducing ligand (APRIL) expression in intestinal epithelial cells for promoting immunoglobulin A (IgA) production. p40 upregulated April gene expression and protein production in mouse small intestine epithelial (MSIE) cells, which were inhibited by blocking EGFR expression and kinase activity. Enteroids from Egfr(fl/fl), but not Egfr(fl/fl)-Vil-Cre mice with EGFR specifically deleted in intestinal epithelial cells, exhibited increased April gene expression by p40 treatment. p40-conditioned media from MSIE cells increased B-cell class switching to IgA(+) cells and IgA production, which was suppressed by APRIL receptor-neutralizing antibodies. Treatment of B cells with p40 did not show any effects on IgA production. p40 treatment increased April gene expression and protein production in small intestinal epithelial cells, fecal IgA levels, IgA(+)B220(+), IgA(+)CD19(+), and IgA(+) plasma cells in lamina propria of Egfr(fl/fl), but not of Egfr(fl/fl)-Vil-Cre, mice. Thus p40 upregulates EGFR-dependent APRIL production in intestinal epithelial cells, which may contribute to promoting IgA production.

  10. Phytic acid protects porcine intestinal epithelial cells from deoxynivalenol (DON) cytotoxicity.

    OpenAIRE

    Pacheco, Graziela Drociunas; Silva,Caio Abércio da; Pinton, Philippe; Oswald, Isabelle

    2012-01-01

    The purpose of this study was to evaluate the effects of phytic acid (IP(6)) as a possible inhibitor of cellular damage induced by toxic substances such as mycotoxins on a porcine intestinal epithelial cell line (IPEC-1). We first observed that a dose of 5 mM phytic acid decreases cell viability and transepithelial electrical resistance (TEER) of cell monolayer. We next investigate the effect of non-cytotoxic dose of phytic acid on the deoxinivalenol (DON) induced decreased TEER. We showed th...

  11. IL-36R signalling activates intestinal epithelial cells and fibroblasts and promotes mucosal healing in vivo.

    Science.gov (United States)

    Scheibe, Kristina; Backert, Ingo; Wirtz, Stefan; Hueber, Axel; Schett, Georg; Vieth, Michael; Probst, Hans Christian; Bopp, Tobias; Neurath, Markus F; Neufert, Clemens

    2017-05-01

    Interleukin (IL)-36R signalling plays a proinflammatory role in different organs including the skin, but the expression of IL-36R ligands and their molecular function in intestinal inflammation are largely unknown. We studied the characteristics of IL-36R ligand expression in IBDs and experimental colitis. The functional role of IL-36R signalling in the intestine was addressed in experimental colitis and wound healing models in vivo by using mice with defective IL-36R signalling (IL-36R-/-) or Myd88, neutralising anti-IL-36R antibodies, recombinant IL-36R ligands and RNA-seq genome expression analysis. Expression of IL-36α and IL-36γ was significantly elevated in active human IBD and experimental colitis. While IL-36γ was predominantly detected in nuclei of the intestinal epithelium, IL-36α was mainly found in the cytoplasm of CD14(+) inflammatory macrophages. Functional studies showed that defective IL-36R signalling causes high susceptibility to acute dextran sodium sulfate colitis and impairs wound healing. Mechanistically, IL-36R ligands released upon mucosal damage activated IL-36R(+) colonic fibroblasts via Myd88 thereby inducing expression of chemokines, granulocyte-macrophage colony-stimulating factor (GM-CSF) and IL-6. Moreover, they induced proliferation of intestinal epithelial cells (IECs) and expression of the antimicrobial protein lipocalin 2. Finally, treatment of experimental intestinal wounds with IL-36R ligands significantly accelerated mucosal healing in vivo. IL-36R signalling is activated upon intestinal damage, stimulates IECs and fibroblasts and drives mucosal healing. Modulation of the IL-36R pathway emerges as a potential therapeutic strategy for induction of mucosal healing in IBD. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  12. Expression of hepatitis C virus proteins in epithelial intestinal cells in vivo

    Science.gov (United States)

    Deforges, Séverine; Evlashev, Alexey; Perret, Magali; Sodoyer, Mireille; Pouzol, Stéphane; Scoazec, Jean-Yves; Bonnaud, Bertrand; Diaz, Olivier; Paranhos-Baccalà, Glaucia; Lotteau, Vincent; André, Patrice

    2004-01-01

    Previous work on hepatitis C virus (HCV) led to the discovery of a new form of viral particles associating viral and lipoprotein elements. These hybrid particles (LVP for lipo-viro-particles) are enriched in triglycerides and contain at least apolipoprotein B (apoB), HCV RNA and core protein. These findings suggest that LVP synthesis could occur in liver and intestine, the two main organs specialized in the production of apoB containing lipoprotein. To precise the site of LVP production, we studied the genetic diversity and phylogenetic relationship of HCV quasispecies from purified LVP, whole serum and liver biopsies from chronically infected patients. HCV quasispecies from LVP and liver differed significantly suggesting that LVP were not predominantly synthetized in the liver but that they might also originate from the intestine. We thus searched for presence of HCV in the small intestine. Paraffin embedded intestinal biopsies from ten HCV chronically infected patients and from twelwe HCV RNA negative controls (10 anti-HCV antibody negative and 2 anti-HCV antibody positive patients) were tested for HCV protein expression. HCV NS3 and NS5A proteins were stained in small intestine epithelial cells in 4 out of 10 chronically infected patients and not in controls. Cells expressing HCV proteins were apoB producing enterocytes but not mucus secreting cells. These data indicate that small intestine can be infected by HCV and identify this organ as a potential reservoir and replication site. This further emphasizes the interaction between lipoprotein metabolism and HCV, and opens new insights in hepatitis C infection and pathophysiology. PMID:15302945

  13. Agglutinating secretory IgA preserves intestinal epithelial cell integrity during apical infection by Shigella flexneri.

    Science.gov (United States)

    Mathias, Amandine; Longet, Stéphanie; Corthésy, Blaise

    2013-08-01

    Shigella flexneri, by invading intestinal epithelial cells (IECs) and inducing inflammatory responses of the colonic mucosa, causes bacillary dysentery. Although M cells overlying Peyer's patches are commonly considered the primary site of entry of S. flexneri, indirect evidence suggests that bacteria can also use IECs as a portal of entry to the lamina propria. Passive delivery of secretory IgA (SIgA), the major immunoglobulin secreted at mucosal surfaces, has been shown to protect rabbits from experimental shigellosis, but no information exists as to its molecular role in maintaining luminal epithelial integrity. We have established that the interaction of virulent S. flexneri with the apical pole of a model intestinal epithelium consisting of polarized Caco-2 cell monolayers resulted in the progressive disruption of the tight junction network and actin depolymerization, eventually resulting in cell death. The lipopolysaccharide (LPS)-specific agglutinating SIgAC5 monoclonal antibody (MAb), but not monomeric IgAC5 or IgGC20 MAbs of the same specificity, achieved protective functions through combined mechanisms, including limitation of the interaction between S. flexneri and epithelial cells, maintenance of the tight junction seal, preservation of the cell morphology, reduction of NF-κB nuclear translocation, and inhibition of proinflammatory mediator secretion. Our results add to the understanding of the function of SIgA-mediated immune exclusion by identifying a mode of action whereby the formation of immune complexes translates into maintenance of the integrity of epithelial cells lining the mucosa. This novel mechanism of protection mediated by SIgA is important to extend the arsenal of effective strategies to fight against S. flexneri mucosal invasion.

  14. The uptake of soluble and particulate antigens by epithelial cells in the mouse small intestine.

    Directory of Open Access Journals (Sweden)

    Savannah E Howe

    Full Text Available Intestinal epithelial cells (IECs overlying the villi play a prominent role in absorption of digested nutrients and establish a barrier that separates the internal milieu from potentially harmful microbial antigens. Several mechanisms by which antigens of dietary and microbial origin enter the body have been identified; however whether IECs play a role in antigen uptake is not known. Using in vivo imaging of the mouse small intestine, we investigated whether epithelial cells (enterocytes play an active role in the uptake (sampling of lumen antigens. We found that small molecular weight antigens such as chicken ovalbumin, dextran, and bacterial LPS enter the lamina propria, the loose connective tissue which lies beneath the epithelium via goblet cell associated passageways. However, epithelial cells overlying the villi can internalize particulate antigens such as bacterial cell debris and inert nanoparticles (NPs, which are then found co-localizing with the CD11c+ dendritic cells in the lamina propria. The extent of NP uptake by IECs depends on their size: 20-40 nm NPs are taken up readily, while NPs larger than 100 nm are taken up mainly by the epithelial cells overlying Peyer's patches. Blocking NPs with small proteins or conjugating them with ovalbumin does not inhibit their uptake. However, the uptake of 40 nm NPs can be inhibited when they are administered with an endocytosis inhibitor (chlorpromazine. Delineating the mechanisms of antigen uptake in the gut is essential for understanding how tolerance and immunity to lumen antigens are generated, and for the development of mucosal vaccines and therapies.

  15. Intestinal epithelial MyD88 is a sensor switching host metabolism towards obesity according to nutritional status.

    Science.gov (United States)

    Everard, Amandine; Geurts, Lucie; Caesar, Robert; Van Hul, Matthias; Matamoros, Sébastien; Duparc, Thibaut; Denis, Raphael G P; Cochez, Perrine; Pierard, Florian; Castel, Julien; Bindels, Laure B; Plovier, Hubert; Robine, Sylvie; Muccioli, Giulio G; Renauld, Jean-Christophe; Dumoutier, Laure; Delzenne, Nathalie M; Luquet, Serge; Bäckhed, Fredrik; Cani, Patrice D

    2014-12-05

    Obesity is associated with a cluster of metabolic disorders, low-grade inflammation and altered gut microbiota. Whether host metabolism is controlled by intestinal innate immune system and the gut microbiota is unknown. Here we report that inducible intestinal epithelial cell-specific deletion of MyD88 partially protects against diet-induced obesity, diabetes and inflammation. This is associated with increased energy expenditure, an improved glucose homeostasis, reduced hepatic steatosis, fat mass and inflammation. Protection is transferred following gut microbiota transplantation to germ-free recipients. We also demonstrate that intestinal epithelial MyD88 deletion increases anti-inflammatory endocannabinoids, restores antimicrobial peptides production and increases intestinal regulatory T cells during diet-induced obesity. Targeting MyD88 after the onset of obesity reduces fat mass and inflammation. Our work thus identifies intestinal epithelial MyD88 as a sensor changing host metabolism according to the nutritional status and we show that targeting intestinal epithelial MyD88 constitutes a putative therapeutic target for obesity and related disorders.

  16. The DNA Sensor AIM2 Maintains Intestinal Homeostasis via Regulation of Epithelial Antimicrobial Host Defense.

    Science.gov (United States)

    Hu, Shuiqing; Peng, Lan; Kwak, Youn-Tae; Tekippe, Erin McElvania; Pasare, Chandrashekhar; Malter, James S; Hooper, Lora V; Zaki, Md Hasan

    2015-12-01

    Microbial pattern molecules in the intestine play immunoregulatory roles via diverse pattern recognition receptors. However, the role of the cytosolic DNA sensor AIM2 in the maintenance of intestinal homeostasis is unknown. Here, we show that Aim2(-/-) mice are highly susceptible to dextran sodium sulfate-induced colitis that is associated with microbial dysbiosis as represented by higher colonic burden of commensal Escherichia coli. Colonization of germ-free mice with Aim2(-/-) mouse microbiota leads to higher colitis susceptibility. In-depth investigation of AIM2-mediated host defense responses reveals that caspase-1 activation and IL-1β and IL-18 production are compromised in Aim2(-/-) mouse colons, consistent with defective inflammasome function. Moreover, IL-18 infusion reduces E. coli burden as well as colitis susceptibility in Aim2(-/-) mice. Altered microbiota in inflammasome-defective mice correlate with reduced expression of several antimicrobial peptides in intestinal epithelial cells. Together, these findings implicate DNA sensing by AIM2 as a regulatory mechanism for maintaining intestinal homeostasis.

  17. The DNA Sensor AIM2 Maintains Intestinal Homeostasis via Regulation of Epithelial Antimicrobial Host Defense

    Directory of Open Access Journals (Sweden)

    Shuiqing Hu

    2015-12-01

    Full Text Available Microbial pattern molecules in the intestine play immunoregulatory roles via diverse pattern recognition receptors. However, the role of the cytosolic DNA sensor AIM2 in the maintenance of intestinal homeostasis is unknown. Here, we show that Aim2−/− mice are highly susceptible to dextran sodium sulfate-induced colitis that is associated with microbial dysbiosis as represented by higher colonic burden of commensal Escherichia coli. Colonization of germ-free mice with Aim2−/− mouse microbiota leads to higher colitis susceptibility. In-depth investigation of AIM2-mediated host defense responses reveals that caspase-1 activation and IL-1β and IL-18 production are compromised in Aim2−/− mouse colons, consistent with defective inflammasome function. Moreover, IL-18 infusion reduces E. coli burden as well as colitis susceptibility in Aim2−/− mice. Altered microbiota in inflammasome-defective mice correlate with reduced expression of several antimicrobial peptides in intestinal epithelial cells. Together, these findings implicate DNA sensing by AIM2 as a regulatory mechanism for maintaining intestinal homeostasis.

  18. Experimental impact of aspirin exposure on rat intestinal bacteria, epithelial cells and cell line.

    Science.gov (United States)

    Upreti, Raj K; Kannan, A; Pant, A B

    2010-10-01

    Aspirin, a commonly used therapeutic non-steroidal anti-inflammatory drug (NSAID) is known to cause gastric mucosal damage. Intestinal bacteria having a regulatory effect on intestinal homeostasis play significant role in NSAID-induced intestinal injury. Bacteria and specific cell lines are considered to be suitable for toxicity screening and testing of chemicals. Therefore, to evaluate and compare in vitro toxicity, cultures of rat intestinal epithelial cells (IEC), isolated bacteria and IEC-6 cell line were assessed for viability, morphometric analysis, membrane transport enzymes and structural constituents for membrane damage, dehydrogenase activity test for respiratory and energy producing processes and esterase activity test for intra- and extra-cellular degradation, following the post exposure to aspirin (0-50 µg mL(- 1)). Similar pattern of dose-dependent changes in these parameters were observed in three types of cells. Similar in situ effects on IEC validated the in vitro findings. These findings indicate that higher aspirin concentrations may alter cellular functions of IEC and gut bacteria. Furthermore, results suggest that gut bacteria and IEC-6 cell line can be used for the initial screening of gastrointestinal cellular toxicity caused by NSAIDs.

  19. Effects of the cathelicidin LL-37 on intestinal epithelial barrier integrity.

    Science.gov (United States)

    Otte, Jan-Michel; Zdebik, Anna-Elisabeth; Brand, Stephan; Chromik, Ansgar M; Strauss, Sarah; Schmitz, Frank; Steinstraesser, Lars; Schmidt, Wolfgang E

    2009-08-07

    The human cathelicidin LL-37 is involved in innate immune responses, angiogenesis and wound healing. Functions in maintenance and re-establishment of intestinal barrier integrity have not been characterized yet. Following direct and indirect stimulation of human colonic HT-29 and Caco-2 cells with LL-37 the cellular viability, rate of apoptosis, proliferation and wound healing were determined. Expression of mucins and growth factors was quantified by real-time PCR and Western blotting. Direct application of LL-37 stimulated migration in Caco-2 cells expressing the proposed LL-37 receptor P2X7. Intestinal epithelial cell (IEC) proliferation was not altered. Indirectly, LL-37 significantly enhanced IEC migration via release of growth factors from subepithelial fibroblasts and IEC. Furthermore, LL-37 induced the expression of protective mucins in IEC and abated tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induced apoptosis in IEC. LL-37 induced signaling is mediated in part by the P2X7 receptor, the epidermal growth factor receptor and the p38 mitogen-activated protein kinase (MAPK). LL-37 contributes to maintenance and re-establishment of the intestinal barrier integrity via direct and indirect pathways. These features, in addition to its known antimicrobial properties, suggest an important role for this peptide in intestinal homeostasis.

  20. Enterocyte shedding and epithelial lining repair following ischemia of the human small intestine attenuate inflammation.

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    Robert A Matthijsen

    Full Text Available BACKGROUND: Recently, we observed that small-intestinal ischemia and reperfusion was found to entail a rapid loss of apoptotic and necrotic cells. This study was conducted to investigate whether the observed shedding of ischemically damaged epithelial cells affects IR induced inflammation in the human small gut. METHODS AND FINDINGS: Using a newly developed IR model of the human small intestine, the inflammatory response was studied on cellular, protein and mRNA level. Thirty patients were consecutively included. Part of the jejunum was subjected to 30 minutes of ischemia and variable reperfusion periods (mean reperfusion time 120 (+/-11 minutes. Ethical approval and informed consent were obtained. Increased plasma intestinal fatty acid binding protein (I-FABP levels indicated loss in epithelial cell integrity in response to ischemia and reperfusion (p<0.001 vs healthy. HIF-1alpha gene expression doubled (p = 0.02 and C3 gene expression increased 4-fold (p = 0.01 over the course of IR. Gut barrier failure, assessed as LPS concentration in small bowel venous effluent blood, was not observed (p = 0.18. Additionally, mRNA expression of HO-1, IL-6, IL-8 did not alter. No increased expression of endothelial adhesion molecules, TNFalpha release, increased numbers of inflammatory cells (p = 0.71 or complement activation, assessed as activated C3 (p = 0.14, were detected in the reperfused tissue. CONCLUSIONS: In the human small intestine, thirty minutes of ischemia followed by up to 4 hours of reperfusion, does not seem to lead to an explicit inflammatory response. This may be explained by a unique mechanism of shedding of damaged enterocytes, reported for the first time by our group.

  1. Commensal Streptococcus salivarius Modulates PPARγ Transcriptional Activity in Human Intestinal Epithelial Cells.

    Science.gov (United States)

    Couvigny, Benoît; de Wouters, Tomas; Kaci, Ghalia; Jacouton, Elsa; Delorme, Christine; Doré, Joël; Renault, Pierre; Blottière, Hervé M; Guédon, Eric; Lapaque, Nicolas

    2015-01-01

    The impact of commensal bacteria in eukaryotic transcriptional regulation has increasingly been demonstrated over the last decades. A multitude of studies have shown direct effects of commensal bacteria from local transcriptional activity to systemic impact. The commensal bacterium Streptococcus salivarius is one of the early bacteria colonizing the oral and gut mucosal surfaces. It has been shown to down-regulate nuclear transcription factor (NF-кB) in human intestinal cells, a central regulator of the host mucosal immune system response to the microbiota. In order to evaluate its impact on a further important transcription factor shown to link metabolism and inflammation in the intestine, namely PPARγ (peroxisome proliferator-activated receptor), we used human intestinal epithelial cell-lines engineered to monitor PPARγ transcriptional activity in response to a wide range of S. salivarius strains. We demonstrated that different strains from this bacterial group share the property to inhibit PPARγ activation independently of the ligand used. First attempts to identify the nature of the active compounds showed that it is a low-molecular-weight, DNase-, proteases- and heat-resistant metabolite secreted by S. salivarius strains. Among PPARγ-targeted metabolic genes, I-FABP and Angptl4 expression levels were dramatically reduced in intestinal epithelial cells exposed to S. salivarius supernatant. Both gene products modulate lipid accumulation in cells and down-regulating their expression might consequently affect host health. Our study shows that species belonging to the salivarius group of streptococci impact both host inflammatory and metabolic regulation suggesting a possible role in the host homeostasis and health.

  2. Boswellia serrata Preserves Intestinal Epithelial Barrier from Oxidative and Inflammatory Damage.

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    Daniela Catanzaro

    Full Text Available Aminosalicylates, corticosteroids and immunosuppressants are currently the therapeutic choices in inflammatory bowel diseases (IBD, however, with limited remission and often serious side effects. Meanwhile complementary and alternative medicine (CAM use is increasing, particularly herbal medicine. Boswellia serrata is a traditional Ayurvedic remedy with anti-inflammatory properties, of interest for its usefulness in IBDs. The mechanism of this pharmacological potential of Boswellia serrata was investigated in colonic epithelial cell monolayers exposed to H2O2 or INF-γ+TNF-α, chosen as in vitro experimental model of intestinal inflammation. The barrier function was evaluated by the transepithelial electrical resistance (TEER and paracellular permeability assay, and by the tight junction proteins (zonula occludens-1, ZO-1 and occludin immunofluorescence. The expression of phosphorylated NF-κB and reactive oxygen species (ROS generation were determined by immunoblot and cytofluorimetric assay, respectively. Boswellia serrata oleo-gum extract (BSE and its pure derivative acetyl-11-keto-β-boswellic acid (AKBA, were tested at 0.1-10 μg/ml and 0.027 μg/ml, respectively. BSE and AKBA safety was demonstrated by no alteration of intestinal cell viability and barrier function and integrity biomarkers. H2O2 or INF-γ+TNF-α treatment of Caco-2 cell monolayers significantly reduced TEER, increased paracellular permeability and caused the disassembly of tight junction proteins occludin and ZO-1. BSE and AKBA pretreatment significantly prevented functional and morphological alterations and also the NF-κB phosphorylation induced by the inflammatory stimuli. At the same concentrations BSE and AKBA counteracted the increase of ROS caused by H2O2 exposure. Data showed the positive correlation of the antioxidant activity with the mechanism involved in the physiologic maintenance of the integrity and function of the intestinal epithelium. This study

  3. Commensal Streptococcus salivarius Modulates PPARγ Transcriptional Activity in Human Intestinal Epithelial Cells.

    Directory of Open Access Journals (Sweden)

    Benoît Couvigny

    Full Text Available The impact of commensal bacteria in eukaryotic transcriptional regulation has increasingly been demonstrated over the last decades. A multitude of studies have shown direct effects of commensal bacteria from local transcriptional activity to systemic impact. The commensal bacterium Streptococcus salivarius is one of the early bacteria colonizing the oral and gut mucosal surfaces. It has been shown to down-regulate nuclear transcription factor (NF-кB in human intestinal cells, a central regulator of the host mucosal immune system response to the microbiota. In order to evaluate its impact on a further important transcription factor shown to link metabolism and inflammation in the intestine, namely PPARγ (peroxisome proliferator-activated receptor, we used human intestinal epithelial cell-lines engineered to monitor PPARγ transcriptional activity in response to a wide range of S. salivarius strains. We demonstrated that different strains from this bacterial group share the property to inhibit PPARγ activation independently of the ligand used. First attempts to identify the nature of the active compounds showed that it is a low-molecular-weight, DNase-, proteases- and heat-resistant metabolite secreted by S. salivarius strains. Among PPARγ-targeted metabolic genes, I-FABP and Angptl4 expression levels were dramatically reduced in intestinal epithelial cells exposed to S. salivarius supernatant. Both gene products modulate lipid accumulation in cells and down-regulating their expression might consequently affect host health. Our study shows that species belonging to the salivarius group of streptococci impact both host inflammatory and metabolic regulation suggesting a possible role in the host homeostasis and health.

  4. Mucosal pathobiology and molecular signature of epithelial barrier dysfunction in the small intestine in irritable bowel syndrome.

    Science.gov (United States)

    González-Castro, Ana M; Martínez, Cristina; Salvo-Romero, Eloísa; Fortea, Marina; Pardo-Camacho, Cristina; Pérez-Berezo, Teresa; Alonso-Cotoner, Carmen; Santos, Javier; Vicario, María

    2017-01-01

    Irritable bowel syndrome (IBS) is one of the most prevalent gastrointestinal disorders in developed countries. Its etiology remains unknown; however, a common finding, regardless of IBS subtype, is the presence of altered intestinal barrier. In fact, signaling and location of cell-to-cell adhesion proteins, in connection with increased immune activity, seem abnormal in the intestinal epithelium of IBS patients. Despite that most research is performed on distal segments of the intestine, altered permeability has been reported in both, the small and the large bowel of all IBS subtypes. The small intestine carries out digestion and nutrient absorption and is also the site where the majority of immune responses to luminal antigens takes place. In fact, the upper intestine is more exposed to environmental antigens than the colon and is also a site of symptom generation. Recent studies have revealed small intestinal structural alterations of the epithelial barrier and mucosal immune activation in association with intestinal dysfunction, suggesting the commitment of the intestine as a whole in the pathogenesis of IBS. This review summarizes the most recent findings on mucosal barrier alterations and its relationship to symptoms arising from the small intestine in IBS, including epithelial structural abnormalities, mucosal immune activation, and microbial dysbiosis, further supporting the hypothesis of an organic origin of IBS. © 2016 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.

  5. 肠道急性放射损伤机制及防治研究%Mechanisms of acute intestine injury by y-ray irradiaton and its therapy

    Institute of Scientific and Technical Information of China (English)

    ZENG Guiying; REN Dongqing; ZHOU Yuankai

    2005-01-01

    BALB/c mice and human intestinal epithelial cells were irradiated to different doses by 60Co γ-rays. They were sampled for chromosome pattern analysis, intestinal morphology, and a number of other biomedical tests to investigate mechanisms of acute intestine injury by γ-ray irradiation and its effective treatment methods. The resuits indicated that:( a ) The intestinal epithelium stem cells from the normal mice (including infantility crypt cells ) could survive at intestinal crypt in mice after irradiation.(b) Bell-shaped curves correlating the crypt survival fraction and exogenous nucleic acids (RNA, DNA)doses were obtained, with the optimal doses for different routes of administration estimated.( c ) Comparing the different routes ( regional intestinal lumen, intramuscular, hypodermic, intraperitoneal and intravenous ) of RNA (ribonucleic acid ) administration, the intravenous injection seemed to be the most effective.( d ) The earlier time of RNA administration, the more effective it was. One injection within 6h after irradiation had the same effect as multi-injections.( e ) The intestinal RNA could enhance the crypt survival of all small intestines segmentes in mice after γ-irradiation, increase the number of leucocytes and platelets in the peripheral blood and enhance the formation ability of bone marrow GM-CFU in mice after γ-irradiation.(f) The intestinal RNA could decrease apoptosis and inhibit the expression of P53 in intestinal crypt cell after γ-irradiation.( g ) The intestinal RNA may improve the cell survival by regulating the cell cycle of the irradiated cells.( h ) The change in the gene expression of the irradiated small intestinal tissue could be induced by the intestinal RNA administration, and 18 new gene sequences or fragments which were related with damage recovery of the intestine RNA administration (the registration number was AF240164-240181 in GeneBank) were found.This fact suggests that: (1) Intestine epithelium stem cell of normal

  6. Regulation of intracellular Zn homeostasis in two intestinal epithelial cell models at various maturation time points.

    Science.gov (United States)

    Gefeller, Eva-Maria; Bondzio, Angelika; Aschenbach, Jörg R; Martens, Holger; Einspanier, Ralf; Scharfen, Franziska; Zentek, Jürgen; Pieper, Robert; Lodemann, Ulrike

    2015-07-01

    After weaning, piglets are often fed diets supplemented with high concentrations of zinc (Zn) to decrease post-weaning diarrhea. The aim of this study was to elucidate the regulation of Zn homeostasis within intestinal epithelial cells during excessive Zn exposure. High Zn concentrations elevated the intracellular Zn level in IPEC-J2 and Caco-2 cells which was influenced by differentiation status and time of exposure. With increasing Zn concentrations, mRNA and protein levels of metallothionein (MT) and zinc transporter 1 (ZnT1) were upregulated, whereas zinc transporter 4 (ZIP4) expression was downregulated. Metal-regulatory transcription factor-1 (MTF1) mRNA expression was upregulated at high Zn concentrations in IPEC-J2 cells, which corresponded to higher intracellular Zn concentrations. Based on these results, we suggest that intestinal epithelial cells adapt the expression of these genes to the amount of extracellular Zn available in order to maintain Zn homeostasis. Cell line-dependent differences in the regulation of Zn homeostasis were detected.

  7. Checkpoint Kinase 1 Activation Enhances Intestinal Epithelial Barrier Function via Regulation of Claudin-5 Expression.

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    Akihiro Watari

    Full Text Available Several stressors are known to influence epithelial tight junction (TJ integrity, but the association between DNA damage and TJ integrity remains unclear. Here we examined the effects of daunorubicin and rebeccamycin, two anti-tumor chemicals that induce DNA damage, on TJ integrity in human intestinal epithelial cells. Daunorubicin and rebeccamycin dose-dependently enhanced transepithelial electrical resistance (TER and decreased flux of the 4 kDa FITC-dextran in Caco-2 cell monolayer. Daunorubicin- or rebeccamycin-induced enhancement of the TJ barrier function partly rescued attenuation of the barrier function by the inflammatory cytokines TNF-α and IFN-γ. Daunorubicin and rebeccamycin increased claudin-5 expression and the product was distributed in the actin cytoskeleton fraction, which was enriched with TJ proteins. Caffeine, which is an inhibitor of ataxia telangiectasia mutated protein (ATM and ataxia telangiectasia mutated and Rad3-related protein (ATR, and the Chk1 inhibitor inhibited the TER increases induced by daunorubicin and rebeccamycin, whereas a Chk2 inhibitor did not. Treatment with Chk1 siRNA also significantly inhibited the TER increases. Induction of claudin-5 expression was inhibited by Chk1 inhibitor and by siRNA treatment. Our results suggest that Chk1 activation by daunorubicin and rebeccamycin induced claudin-5 expression and enhanced TJ barrier function in Caco-2 cell monolayer, which suggests a link between DNA damage and TJ integrity in the human intestine.

  8. Checkpoint Kinase 1 Activation Enhances Intestinal Epithelial Barrier Function via Regulation of Claudin-5 Expression.

    Science.gov (United States)

    Watari, Akihiro; Hasegawa, Maki; Yagi, Kiyohito; Kondoh, Masuo

    2016-01-01

    Several stressors are known to influence epithelial tight junction (TJ) integrity, but the association between DNA damage and TJ integrity remains unclear. Here we examined the effects of daunorubicin and rebeccamycin, two anti-tumor chemicals that induce DNA damage, on TJ integrity in human intestinal epithelial cells. Daunorubicin and rebeccamycin dose-dependently enhanced transepithelial electrical resistance (TER) and decreased flux of the 4 kDa FITC-dextran in Caco-2 cell monolayer. Daunorubicin- or rebeccamycin-induced enhancement of the TJ barrier function partly rescued attenuation of the barrier function by the inflammatory cytokines TNF-α and IFN-γ. Daunorubicin and rebeccamycin increased claudin-5 expression and the product was distributed in the actin cytoskeleton fraction, which was enriched with TJ proteins. Caffeine, which is an inhibitor of ataxia telangiectasia mutated protein (ATM) and ataxia telangiectasia mutated and Rad3-related protein (ATR), and the Chk1 inhibitor inhibited the TER increases induced by daunorubicin and rebeccamycin, whereas a Chk2 inhibitor did not. Treatment with Chk1 siRNA also significantly inhibited the TER increases. Induction of claudin-5 expression was inhibited by Chk1 inhibitor and by siRNA treatment. Our results suggest that Chk1 activation by daunorubicin and rebeccamycin induced claudin-5 expression and enhanced TJ barrier function in Caco-2 cell monolayer, which suggests a link between DNA damage and TJ integrity in the human intestine.

  9. Autophagy enhances intestinal epithelial tight junction barrier function by targeting claudin-2 protein degradation.

    Science.gov (United States)

    Nighot, Prashant K; Hu, Chien-An Andy; Ma, Thomas Y

    2015-03-13

    Autophagy is an intracellular degradation pathway and is considered to be an essential cell survival mechanism. Defects in autophagy are implicated in many pathological processes, including inflammatory bowel disease. Among the innate defense mechanisms of intestinal mucosa, a defective tight junction (TJ) barrier has been postulated as a key pathogenic factor in the causation and progression of inflammatory bowel disease by allowing increased antigenic permeation. The cross-talk between autophagy and the TJ barrier has not yet been described. In this study, we present the novel finding that autophagy enhances TJ barrier function in Caco-2 intestinal epithelial cells. Nutrient starvation-induced autophagy significantly increased transepithelial electrical resistance and reduced the ratio of sodium/chloride paracellular permeability. Nutrient starvation reduced the paracellular permeability of small-sized urea but not larger molecules. The role of autophagy in the modulation of paracellular permeability was confirmed by pharmacological induction as well as pharmacological and genetic inhibition of autophagy. Consistent with the autophagy-induced reduction in paracellular permeability, a marked decrease in the level of the cation-selective, pore-forming TJ protein claudin-2 was observed after cell starvation. Starvation reduced the membrane presence of claudin-2 and increased its cytoplasmic, lysosomal localization. Therefore, our data show that autophagy selectively reduces epithelial TJ permeability of ions and small molecules by lysosomal degradation of the TJ protein claudin-2.

  10. Effects of hydrogen peroxide on mitochondrial gene expression of intestinal epithelial cells

    Institute of Scientific and Technical Information of China (English)

    Jian-Ming Li; Qian Cai; Hong Zhou; Guang-Xia Xiao

    2002-01-01

    AIM: To study the effects of hydrogen peroxide on mitochondrial gene expression of intestinal epithelial cells in in vitro model of hydrogen peroxide-stimulated SW-480 cells.METHODS: RNA of hydrogen peroxide-induced SW-480 cells was isolated, and reverse-transcriptional polymerase chain reaction was performed to study gene expression of ATPase subunit 6, ATPase subunit 8, cytochrome c oxidase subunit Ⅰ (COⅠ), cytochrome coxidase subuit Ⅱ (COⅡ) and cytochrome c oxidase subunit Ⅲ (COⅢ). Mitochondria were isolated and activities of mitochondrial cytochrome c oxidase and ATPase were also measured simultaneously.RESULTS: Hydrogen peroxide led to differential expression of mitochondrial genes with some genes up-regulated or down-regulated in a dose dependent manner. Differences were very obvious in expressions of mitochondrial genes of cells treated with hydrogen peroxide in a concentration of 400 μmol/L or 4 mmol/L. In general, differential expression of mitochondrial genes was characterized by up-regulation of mitochondrial genes in the concentration of 400 μmol/L and down-regulation in the concentration of 4 mmol/L. In consistence with changes in mitochondrial gene expressions, hydrogen peroxide resulted in decreased activities of cytochrome c oxidase and ATPase.CONCLUSIONS: The differential expression of mitochondrial genes encoding cytochrome c oxidase and ATPase is involved in apoptosis of intestinal epithelial cells by affecting activities of cytochorme c oxidase and ATPase.

  11. Role of mitochondrial dysfunction in hydrogen peroxide-induced apoptosis of intestinal epithelial cells

    Institute of Scientific and Technical Information of China (English)

    Jian-Ming Li; Hong Zhou; Qian Cai; Guang-Xia Xiao

    2003-01-01

    AIM: To study the role of mitochondrial dysfunction in hydrogen peroxide-induced apoptosis of intestinal epithelial cells.METHODS: Hydrogen peroxide-induced apoptosis of human intestinal epithelial cell line SW-480 was established. Cell apoptosis was determined by Annexin-V and PI doublestained flow cytometry and DNA gel electrophoresis.Morphological changes were examined with light and electron microscopy. For other observations, mitochondrial function,cytochrome c release, mitochondrial translocation and membrane potential were determined simultaneously.RESULTS: Percentage of apoptotic cells induced with 400μ mol/L hydrogen peroxide increased significantly at I h or 3h after stimulation and recovered rapidly. Meanwhile percentage of apoptotic cells induced with 4 mmol/L hydrogen peroxide increased with time. In accordance with these changes, we observed decreased mitochondrial function in 400 μmol/L H2O2-stimualted cells at 1 h or 3 h and in 4 mmol/L H2O2-stimualted cells at times examined.Correspondingly, swelling cristae and vacuole-like mitochondria were noted. Release of cytochrome c,decreased mitochondrial membrane potential and mitochondrial translocation were also found to be the early signs of apoptosis.CONCLUSION: Dysfunctional mitochondria play a role in the apoptosis of SW-480 cell line induced by hydrogen peroxide.

  12. Activation of NF-κB and apoptosis of intestinal epithelial cells induced by hydrogen peroxide

    Institute of Scientific and Technical Information of China (English)

    李建明; 周红; 蔡黔; 肖光夏

    2002-01-01

    In vitro model of hydrogen peroxide induced apoptosis of SW-480 cells was used to investigate the role of NF-κB in the pathogenesis of reactive oxygen species induced apoptosis of intestinal epithelial cells. Methods: Ultra-structural changes were observed.Apoptosis of SW-480 cell line was determined by Annexin-V and PI double-stained flow cytometry. Nuclear translocation of NF-κB was determined by anti-NF-κB polyclonal antibody and EB double-staining. NF-κB activity was studied by electrophoretic mobility shift assays. RTPCR was performed to study expression of NF-κB mRNA. Results: Hydrogen peroxide led to apoptosis of SW-480 cells, condensed or semilunar chromatin even apoptotic bodies could be observed. Nuclear translocation of NF-κB,increase of NF-κB activity and expression of NF-κB mRNA were found simultaneously. Conclusions: Early activation of NF-κ B may be one of the mechanisms of apoptosis in intestinal epithelial cells by reactive oxygen species.

  13. Lactobacillus acidophilus binds to MUC3 component of cultured intestinal epithelial cells with highest affinity.

    Science.gov (United States)

    Das, Jugal Kishore; Mahapatra, Rajani Kanta; Patro, Shubhransu; Goswami, Chandan; Suar, Mrutyunjay

    2016-04-01

    Lactobacillus strains have been shown to adhere to the mucosal components of intestinal epithelial cells. However, established in vitro adhesion assays have several drawbacks in assessing the adhesion of new Lactobacillus strains. The present study aimed to compare the adhesion of four different Lactobacillus strains and select the most adherent microbe, based on in silico approach supported by in vitro results. The mucus-binding proteins in Lactobacillus acidophilus, L. plantarum, L. brevis and L. fermentum were identified and their capacities to interact with intestinal mucin were compared by molecular docking analysis. Lactobacillus acidophilus had the maximal affinity of binding to mucin with predicted free energy of -6.066 kcal mol(-1) Further, in vitro experimental assay of adhesion was performed to validate the in silico results. The adhesion of L. acidophilus to mucous secreting colon epithelial HT-29 MTX cells was highest at 12%, and it formed biofilm with maximum depth (Z = 84 μm). Lactobacillus acidophilus was determined to be the most adherent strain in the study. All the Lactobacillus strains tested in this study, displayed maximum affinity of binding to MUC3 component of mucus as compared to other gastrointestinal mucins. These findings may have importance in the design of probiotics and health care management.

  14. Nivalenol induces oxidative stress and increases deoxynivalenol pro-oxidant effect in intestinal epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Del Regno, Marisanta; Adesso, Simona; Popolo, Ada [Department of Pharmacy, School of Pharmacy, University of Salerno, Via Giovanni Paolo II, 132–84084 Fisciano, Salerno (Italy); Quaroni, Andrea [Department of Biomedical Sciences, Cornell University, Veterinary Research Tower, Cornell University, Ithaca, NY 14853–6401 (United States); Autore, Giuseppina [Department of Pharmacy, School of Pharmacy, University of Salerno, Via Giovanni Paolo II, 132–84084 Fisciano, Salerno (Italy); Severino, Lorella [Department of Pathology and Animal Health, Division of Toxicology, School of Veterinary Medicine, University of Naples “Federico II”, Via Delpino 1, 80137 Naples (Italy); Marzocco, Stefania, E-mail: smarzocco@unisa.it [Department of Pharmacy, School of Pharmacy, University of Salerno, Via Giovanni Paolo II, 132–84084 Fisciano, Salerno (Italy)

    2015-06-01

    Mycotoxins are secondary fungal metabolites often found as contaminants in almost all agricultural commodities worldwide, and the consumption of food or feed contaminated by mycotoxins represents a major risk for human and animal health. Reactive oxygen species are normal products of cellular metabolism. However, disproportionate generation of reactive oxygen species poses a serious problem to bodily homeostasis and causes oxidative tissue damage. In this study we analyzed the effect of two trichothecenes mycotoxins: nivalenol and deoxynivalenol, alone and in combination, on oxidative stress in the non-tumorigenic intestinal epithelial cell line IEC-6. Our results indicate the pro-oxidant nivalenol effect in IEC-6, the stronger pro-oxidant effect of nivalenol when compared to deoxynivalenol and, interestingly, that nivalenol increases deoxynivalenol pro-oxidative effects. Mechanistic studies indicate that the observed effects were mediated by NADPH oxidase, calcium homeostasis alteration, NF-kB and Nrf2 pathways activation and by iNOS and nitrotyrosine formation. The toxicological interaction by nivalenol and deoxynivalenol reported in this study in IEC-6, points out the importance of the toxic effect of these mycotoxins, mostly in combination, further highlighting the risk assessment process of these toxins that are of growing concern. - Highlights: • Nivalenol induces oxidative stress in intestinal epithelial cells (IECs). • Nivalenol increases deoxynivalenol pro-oxidant effects in IECs. • Nivalenol and deoxynivalenol trigger antioxidant response IECs. • These results indicate the importance of mycotoxins co-contamination.

  15. Programming of Intestinal Epithelial Differentiation by IL-33 Derived from Pericryptal Fibroblasts in Response to Systemic Infection

    Directory of Open Access Journals (Sweden)

    Mousumi Mahapatro

    2016-05-01

    Full Text Available The intestinal epithelium constitutes an efficient barrier against the microbial flora. Here, we demonstrate an unexpected function of IL-33 as a regulator of epithelial barrier functions. Mice lacking IL-33 showed decreased Paneth cell numbers and lethal systemic infection in response to Salmonella typhimurium. IL-33 was produced upon microbial challenge by a distinct population of pericryptal fibroblasts neighboring the intestinal stem cell niche. IL-33 programmed the differentiation of epithelial progenitors toward secretory IEC including Paneth and goblet cells. Finally, IL-33 suppressed Notch signaling in epithelial cells and induced expression of transcription factors governing differentiation into secretory IEC. In summary, we demonstrate that gut pericryptal fibroblasts release IL-33 to translate bacterial infection into an epithelial response to promote antimicrobial defense.

  16. CLMP is essential for intestinal development, but does not play a key role in cellular processes involved in intestinal epithelial development.

    Directory of Open Access Journals (Sweden)

    Christine S van der Werf

    Full Text Available Loss-of-function mutations in CLMP have been found in patients with Congenital Short Bowel Syndrome (CSBS, suggesting that its encoded protein plays a major role in intestinal development. CLMP is a membrane protein that co-localizes with tight junction proteins, but its function is largely unknown. We expressed wild-type (WT-CLMP and a mutant-CLMP (associated with CSBS in human intestinal epithelial T84 cells that, as we show here, do not produce endogenous CLMP. We investigated the effects of WT-CLMP and mutant-CLMP proteins on key cellular processes that are important for intestinal epithelial development, including migration, proliferation, viability and transepithelial resistance. Our data showed that expression of WT-CLMP or mutant-CLMP does not affect any of these processes. Moreover, our aggregation assays in CHO cells show that CLMP does not act as a strong adhesion molecule. Thus, our data suggest that, in the in vitro model systems we used, the key processes involved in intestinal epithelial development appear to be unaffected by WT-CLMP or mutant-CLMP. Further research is needed to determine the role of CLMP in the development of the intestine.

  17. Receptor-like Molecules on Human Intestinal Epithelial Cells Interact with an Adhesion Factor from Lactobacillus reuteri

    OpenAIRE

    Matsuo, Yosuke; MIYOSHI, Yukihiro; Okada, Sanae; SATOH, Eiichi

    2012-01-01

    A surface protein of Lactobacillus reuteri, mucus adhesion-promoting protein (MapA), is considered to be an adhesion factor. MapA is expressed in L. reuteri strains and adheres to piglet gastric mucus, collagen type I, and human intestinal epithelial cells such as Caco-2. The aim of this study was to identify molecules that mediate the attachment of MapA from L. reuteri to the intestinal epithelial cell surface by investigating the adhesion of MapA to receptor-like molecules on Caco-2 cells. ...

  18. Wnt-reporter expression pattern in the mouse intestine during homeostasis

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    Carroll Kevin H

    2008-12-01

    Full Text Available Abstract Background The canonical Wnt signaling pathway is a known regulator of cell proliferation during development and maintenance of the intestinal epithelium. Perturbations in this pathway lead to aberrant epithelial proliferation and intestinal cancer. In the mature intestine, proliferation is confined to the relatively quiescent stem cells and the rapidly cycling transient-amplifying cells in the intestinal crypts. Although the Wnt signal is believed to regulate all proliferating intestinal cells, surprisingly, this has not been thoroughly demonstrated. This important determination has implications on intestinal function, especially during epithelial expansion and regeneration, and warrants an extensive characterization of Wnt-activated cells. Methods To identify intestinal epithelial cells that actively receive a Wnt signal, we analyzed intestinal Wnt-reporter expression patterns in two different mouse lines using immunohistochemistry, enzymatic activity, in situ hybridization and qRT-PCR, then corroborated results with reporter-independent analyses. Wnt-receiving cells were further characterized for co-expression of proliferation markers, putative stem cell markers and cellular differentiation markers using an immunohistochemical approach. Finally, to demonstrate that Wnt-reporter mice have utility in detecting perturbations in intestinal Wnt signaling, the reporter response to gamma-irradiation was examined. Results Wnt-activated cells were primarily restricted to the base of the small intestinal and colonic crypts, and were highest in numbers in the proximal small intestine, decreasing in frequency in a gradient toward the large intestine. Interestingly, the majority of the Wnt-reporter-expressing cells did not overlap with the transient-amplifying cell population. Further, while Wnt-activated cells expressed the putative stem cell marker Musashi-1, they did not co-express DCAMKL-1 or cell differentiation markers. Finally, gamma

  19. Progressive Depletion of Rough Endoplasmic Reticulum in Epithelial Cells of the Small Intestine in Monosodium Glutamate Mice Model of Obesity

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    Kazuhiko Nakadate

    2016-01-01

    Full Text Available Chronic obesity is a known risk factor for metabolic syndrome. However, little is known about pathological changes in the small intestine associated with chronic obesity. This study investigated cellular and subcellular level changes in the small intestine of obese mice. In this study, a mouse model of obesity was established by early postnatal administration of monosodium glutamate. Changes in body weight were monitored, and pathological changes in the small intestine were evaluated using hematoxylin-eosin and Nissl staining and light and electron microscopy. Consequently, obese mice were significantly heavier compared with controls from 9 weeks of age. Villi in the small intestine of obese mice were elongated and thinned. There was reduced hematoxylin staining in the epithelium of the small intestine of obese mice. Electron microscopy revealed a significant decrease in and shortening of rough endoplasmic reticulum in epithelial cells of the small intestine of obese mice compared with normal mice. The decrease in rough endoplasmic reticulum in the small intestine epithelial cells of obese mice indicates that obesity starting in childhood influences various functions of the small intestine, such as protein synthesis, and could impair both the defense mechanism against invasion of pathogenic microbes and nutritional absorption.

  20. Progressive Depletion of Rough Endoplasmic Reticulum in Epithelial Cells of the Small Intestine in Monosodium Glutamate Mice Model of Obesity.

    Science.gov (United States)

    Nakadate, Kazuhiko; Motojima, Kento; Hirakawa, Tomoya; Tanaka-Nakadate, Sawako

    2016-01-01

    Chronic obesity is a known risk factor for metabolic syndrome. However, little is known about pathological changes in the small intestine associated with chronic obesity. This study investigated cellular and subcellular level changes in the small intestine of obese mice. In this study, a mouse model of obesity was established by early postnatal administration of monosodium glutamate. Changes in body weight were monitored, and pathological changes in the small intestine were evaluated using hematoxylin-eosin and Nissl staining and light and electron microscopy. Consequently, obese mice were significantly heavier compared with controls from 9 weeks of age. Villi in the small intestine of obese mice were elongated and thinned. There was reduced hematoxylin staining in the epithelium of the small intestine of obese mice. Electron microscopy revealed a significant decrease in and shortening of rough endoplasmic reticulum in epithelial cells of the small intestine of obese mice compared with normal mice. The decrease in rough endoplasmic reticulum in the small intestine epithelial cells of obese mice indicates that obesity starting in childhood influences various functions of the small intestine, such as protein synthesis, and could impair both the defense mechanism against invasion of pathogenic microbes and nutritional absorption.

  1. Lymphocyte Cc Chemokine Receptor 9 and Epithelial Thymus-Expressed Chemokine (Teck) Expression Distinguish the Small Intestinal Immune Compartment

    OpenAIRE

    2000-01-01

    The immune system has evolved specialized cellular and molecular mechanisms for targeting and regulating immune responses at epithelial surfaces. Here we show that small intestinal intraepithelial lymphocytes and lamina propria lymphocytes migrate to thymus-expressed chemokine (TECK). This attraction is mediated by CC chemokine receptor (CCR)9, a chemoattractant receptor expressed at high levels by essentially all CD4+ and CD8+ T lymphocytes in the small intestine. Only a small subset of lymp...

  2. Amyloid precursor protein mediated changes in intestinal epithelial phenotype in vitro.

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    Kendra L Puig

    Full Text Available Although APP and its proteolytic metabolites have been well examined in the central nervous system, there remains limited information of their functions outside of the brain. For example, amyloid precursor protein (APP and amyloid beta (Aβ immunoreactivity have both been demonstrated in intestinal epithelial cells. Based upon the critical role of these cells in absorption and secretion, we sought to determine whether APP or its metabolite amyloid β (Aβ, had a definable function in these cells.The human colonic epithelial cell line, Caco-2 cells, were cultured to examine APP expression and Aβ secretion, uptake, and stimulation. Similar to human colonic epithelium stains, Caco-2 cells expressed APP. They also secreted Aβ 1-40 and Aβ 1-42, with LPS stimulating higher concentrations of Aβ 1-40 secretion. The cells also responded to Aβ 1-40 stimulation by increasing IL-6 cytokine secretion and decreasing cholesterol uptake. Conversely, stimulation with a sAPP-derived peptide increased cholesterol uptake. APP was associated with CD36 but not FATP4 in co-IP pull down experiments from the Caco-2 cells. Moreover, stimulation of APP with an agonist antibody acutely decreased CD36-mediated cholesterol uptake.APP exists as part of a multi-protein complex with CD36 in human colonic epithelial cells where its proteolytic fragments have complex, reciprocal roles in regulating cholesterol uptake. A biologically active peptide fragment from the N-terminal derived, sAPP, potentiated cholesterol uptake while the β secretase generated product, Aβ1-40, attenuated it. These data suggest that APP is important in regulating intestinal cholesterol uptake in a fashion dependent upon specific proteolytic pathways. Moreover, this biology may be applicable to cells beyond the gastrointestinal tract.

  3. Immunostimulated Arginase II Expression in Intestinal Epithelial Cells Reduces Nitric Oxide Production and Apoptosis.

    Science.gov (United States)

    Talavera, Maria M; Nuthakki, Sushma; Cui, Hongmei; Jin, Yi; Liu, Yusen; Nelin, Leif D

    2017-01-01

    Increased production of nitric oxide (NO) and subsequent local cytotoxicity to mucosal epithelial cells has been proposed as a putative mechanism involved in the development of necrotizing enterocolitis (NEC). Intestinal epithelial cells (IECs) metabolize L-arginine to either nitric oxide (NO) by NO synthase (NOS) or to L-ornithine and urea by arginase. L-ornithine is the first step in polyamine synthesis important for cell proliferation, while NO production can lead to apoptosis. We hypothesized that in IECs immunostimulation increases both NOS and arginase expression, and that arginase activity mitigates NO production and apoptosis. Rat intestinal epithelial cells (rIEC-6) were immunostimulated by either incubation with lipopolysaccharide (LPS) alone for 24 h or by incubation with conditioned media (CM) for 24 h. CM was obtained from RAW 264.7 cells (a macrophage cell line) treated with LPS (E. coli 0127:B8; 1 μg/ml) for 4 h. The rIEC-6 stimulated with LPS or with CM had significantly higher levels of inducible NOS (iNOS) protein, NO production, and arginase II protein than did the control cells. Direct LPS stimulation of rIEC-6 produced a less robust increase in iNOS expression and NO (represented as nitrite percent of control) than did CM stimulation. Inhibition of arginase using N(ω) hydroxyl-L-arginine (NOHA) further increased stimulated NO production in rIEC-6. Viable cell numbers were significantly lower in CM stimulated cells after 24 h than in controls, and inhibition of arginase activity with NOHA resulted in a further significant decrease in viable cell numbers. We conclude that immunostimulated arginase expression of rIEC-6 cells tempers cytokine-induced iNOS-derived NO production and apoptosis.

  4. ASSESSMENT OF MIXED MINERALS BY OBSERVING INTESTINAL EPITHELIAL CELL ALTERATIONS IN PIGLETS

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    Chamroon Maneewan

    2014-01-01

    Full Text Available The experiment was conducted to assess the effect of dietary Mixed Minerals (MM on intestinal epithelial cell morphology, villus height and area and growth performance in piglets. Thirty two-month-old hybrid piglets (15 kg BW (Large White × Landrace × Duroc, consisting of 15 castrated males and 15 females, were allocated into three experimental groups with five replicates of one castrated male and one female per replicate. The basal diet was supplemented with MM at 0 (control, 0.05 and 0.1% for 30 days. Compared with dome-shaped epithelial cells on the intestinal villus apical surface, further protuberated dome-shaped cells were observed in the 0.05% MM group and cell clusters comprised of dome-shaped cells appeared in the 0.1% MM group. However, the villus height and villus area as well as growth performance were not affected, except that the feed intake and average daily feed intake of the 0.1% MM group increased compared with those of the 0.05% MM group (p<0.05; as well, body weight gain of the 0.1% MM group was 4% greater than the control. These results suggest that MM can stimulate functions of epithelial cells with increasing levels of MM, but that they have no power to improve body weight gain resulting from increased villus activity and that MM have no function to affect growth performance but might affect other biochemical functions, such as immunity processes in the body.

  5. Death-associated protein kinase controls STAT3 activity in intestinal epithelial cells.

    Science.gov (United States)

    Chakilam, Saritha; Gandesiri, Muktheshwar; Rau, Tilman T; Agaimy, Abbas; Vijayalakshmi, Mahadevan; Ivanovska, Jelena; Wirtz, Ralph M; Schulze-Luehrmann, Jan; Benderska, Natalya; Wittkopf, Nadine; Chellappan, Ajithavalli; Ruemmele, Petra; Vieth, Michael; Rave-Fränk, Margret; Christiansen, Hans; Hartmann, Arndt; Neufert, Clemens; Atreya, Raja; Becker, Christoph; Steinberg, Pablo; Schneider-Stock, Regine

    2013-03-01

    The TNF-IL-6-STAT3 pathway plays a crucial role in promoting ulcerative colitis-associated carcinoma (UCC). To date, the negative regulation of STAT3 is poorly understood. Interestingly, intestinal epithelial cells of UCC in comparison to ulcerative colitis show high expression levels of anti-inflammatory death-associated protein kinase (DAPK) and low levels of pSTAT3. Accordingly, epithelial DAPK expression was enhanced in STAT3(IEC-KO) mice. To unravel a possible regulatory mechanism, we used an in vitro TNF-treated intestinal epithelial cell model. We identified a new function of DAPK in suppressing TNF-induced STAT3 activation as DAPK siRNA knockdown and treatment with a DAPK inhibitor potentiated STAT3 activation, IL-6 mRNA expression, and secretion. DAPK attenuated STAT3 activity directly by physical interaction shown in three-dimensional structural modeling. This model suggests that DAPK-induced conformational changes in the STAT3 dimer masked its nuclear localization signal. Alternatively, pharmacological inactivation of STAT3 led to an increase in DAPK mRNA and protein levels. Chromatin immunoprecipitation showed that STAT3 restricted DAPK expression by promoter binding, thereby reinforcing its own activation by inducing IL-6. This novel negative regulation principle might balance TNF-induced inflammation and seems to play an important role in the inflammation-associated transformation process as confirmed in an AOM+DSS colon carcinogenesis mouse model. DAPK as a negative regulator of STAT3 emerges as therapeutic option in the treatment of ulcerative colitis and UCC.

  6. Immunostimulated Arginase II Expression in Intestinal Epithelial Cells Reduces Nitric Oxide Production and Apoptosis

    Science.gov (United States)

    Talavera, Maria M.; Nuthakki, Sushma; Cui, Hongmei; Jin, Yi; Liu, Yusen; Nelin, Leif D.

    2017-01-01

    Increased production of nitric oxide (NO) and subsequent local cytotoxicity to mucosal epithelial cells has been proposed as a putative mechanism involved in the development of necrotizing enterocolitis (NEC). Intestinal epithelial cells (IECs) metabolize L-arginine to either nitric oxide (NO) by NO synthase (NOS) or to L-ornithine and urea by arginase. L-ornithine is the first step in polyamine synthesis important for cell proliferation, while NO production can lead to apoptosis. We hypothesized that in IECs immunostimulation increases both NOS and arginase expression, and that arginase activity mitigates NO production and apoptosis. Rat intestinal epithelial cells (rIEC-6) were immunostimulated by either incubation with lipopolysaccharide (LPS) alone for 24 h or by incubation with conditioned media (CM) for 24 h. CM was obtained from RAW 264.7 cells (a macrophage cell line) treated with LPS (E. coli 0127:B8; 1 μg/ml) for 4 h. The rIEC-6 stimulated with LPS or with CM had significantly higher levels of inducible NOS (iNOS) protein, NO production, and arginase II protein than did the control cells. Direct LPS stimulation of rIEC-6 produced a less robust increase in iNOS expression and NO (represented as nitrite percent of control) than did CM stimulation. Inhibition of arginase using Nω hydroxyl-L-arginine (NOHA) further increased stimulated NO production in rIEC-6. Viable cell numbers were significantly lower in CM stimulated cells after 24 h than in controls, and inhibition of arginase activity with NOHA resulted in a further significant decrease in viable cell numbers. We conclude that immunostimulated arginase expression of rIEC-6 cells tempers cytokine-induced iNOS-derived NO production and apoptosis.

  7. Alpha-ketoglutarate inhibits glutamine degradation and enhances protein synthesis in intestinal porcine epithelial cells.

    Science.gov (United States)

    Yao, Kang; Yin, Yulong; Li, Xilong; Xi, Pengbin; Wang, Junjun; Lei, Jian; Hou, Yongqing; Wu, Guoyao

    2012-06-01

    α-Ketoglutarate (AKG) is a key intermediate in glutamine metabolism. Emerging evidence shows beneficial effects of AKG on clinical and experimental nutrition, particularly with respect to intestinal growth and integrity. However, the underlying mechanisms are unknown. Intestinal porcine epithelial cells (IPEC-1) were used to test the hypothesis that AKG inhibits glutamine degradation and enhances protein synthesis. IPEC-1 cells were cultured for 3 days in Dulbecco's modified Eagle's-F12 Ham medium (DMEM-F12) containing 0, 0.2, 0.5 or 2 mM of AKG. At the end of the 3-day culture, cells were used to determine L-[U-14C]glutamine utilization, protein concentration, protein synthesis, and the total and phosphorylated levels of the mammalian target of the rapamycin (mTOR), ribosomal protein S6 kinase-1 (S6K1) and eukaryotic initiation factor (eIF) 4E-binding protein-1 (4E-BP1). Compared with 0 mM of AKG (control), 0.2 and 0.5 mM of AKG dose-dependently reduced (P<0.05) glutamine degradation and the production of glutamate, alanine and aspartate in IPEC-1 cells. Addition of 0.5 and 2 mM of AKG to culture medium enhanced protein synthesis (P<0.05) by 78 and 101% without affecting protein degradation, compared to the control group. Rapamycin (50 nM; a potent inhibitor of mTOR) attenuated the stimulatory effect of AKG on protein synthesis. Consistent with these metabolic data, the addition of 0.5 or 2 mM of AKG to culture medium increased (P<0.05) the phosphorylated levels of mTOR, S6k1 and 4E-BP1 proteins. Collectively, these results indicate that AKG can spare glutamine and activate the mTOR signaling pathway to stimulate protein synthesis in intestinal epithelial cells.

  8. Rebeccamycin Attenuates TNF-α-Induced Intestinal Epithelial Barrier Dysfunction by Inhibiting Myosin Light Chain Kinase Production

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    Akihiro Watari

    2017-04-01

    Full Text Available Background/Aims: Although proinflammatory cytokine–induced disruption of intestinal epithelial barrier integrity is associated with intestinal inflammatory disease, effective treatment for barrier dysfunction is lacking. Previously, we demonstrated that rebeccamycin alleviates epithelial barrier dysfunction induced by inflammatory cytokines in Caco-2 cell monolayers; however, the underlying mechanism remained unclear. Here, we investigated the mechanism by which rebeccamycin protects the epithelial barrier function of Caco-2 cells exposed to TNF-α. Methods: To confirm the epithelial barrier function of Caco-2 cell monolayers, transepithelial electrical resistance (TER and paracellular permeability were measured. Production levels and localization of tight junction (TJ proteins were analyzed by immunoblot and immunofluorescence, respectively. Phosphorylated myosin light chain (pMLC and MLC kinase (MLCK mRNA expression levels were determined by immunoblot and quantitative RT-PCR, respectively. Results: Rebeccamycin attenuated the TNF-α-induced reduction in TER and increase in paracellular permeability. Rebeccamycin increased claudin-5 expression, but not claudin-1, -2, -4, occludin or ZO-1 expression, and prevented the TNF-α-induced changes in ZO-1 and occludin localization. Rebeccamycin suppressed the TNF-α-induced increase in MLCK mRNA expression, thus suppressing MLC phosphorylation. The rebeccamycin-mediated reduction in MLCK production and protection of epithelial barrier function were alleviated by Chk1 inhibition. Conclusion: Rebeccamycin attenuates TNF-α-induced disruption of intestinal epithelial barrier integrity by inducing claudin-5 expression and suppressing MLCK production via Chk1 activation.

  9. Rebeccamycin Attenuates TNF-α-Induced Intestinal Epithelial Barrier Dysfunction by Inhibiting Myosin Light Chain Kinase Production.

    Science.gov (United States)

    Watari, Akihiro; Sakamoto, Yuta; Hisaie, Kota; Iwamoto, Kazuki; Fueta, Miho; Yagi, Kiyohito; Kondoh, Masuo

    2017-01-01

    Although proinflammatory cytokine-induced disruption of intestinal epithelial barrier integrity is associated with intestinal inflammatory disease, effective treatment for barrier dysfunction is lacking. Previously, we demonstrated that rebeccamycin alleviates epithelial barrier dysfunction induced by inflammatory cytokines in Caco-2 cell monolayers; however, the underlying mechanism remained unclear. Here, we investigated the mechanism by which rebeccamycin protects the epithelial barrier function of Caco-2 cells exposed to TNF-α. To confirm the epithelial barrier function of Caco-2 cell monolayers, transepithelial electrical resistance (TER) and paracellular permeability were measured. Production levels and localization of tight junction (TJ) proteins were analyzed by immunoblot and immunofluorescence, respectively. Phosphorylated myosin light chain (pMLC) and MLC kinase (MLCK) mRNA expression levels were determined by immunoblot and quantitative RT-PCR, respectively. Rebeccamycin attenuated the TNF-α-induced reduction in TER and increase in paracellular permeability. Rebeccamycin increased claudin-5 expression, but not claudin-1, -2, -4, occludin or ZO-1 expression, and prevented the TNF-α-induced changes in ZO-1 and occludin localization. Rebeccamycin suppressed the TNF-α-induced increase in MLCK mRNA expression, thus suppressing MLC phosphorylation. The rebeccamycin-mediated reduction in MLCK production and protection of epithelial barrier function were alleviated by Chk1 inhibition. Rebeccamycin attenuates TNF-α-induced disruption of intestinal epithelial barrier integrity by inducing claudin-5 expression and suppressing MLCK production via Chk1 activation. © 2017 The Author(s)Published by S. Karger AG, Basel.

  10. Matrix metalloproteinase 9-induced increase in intestinal epithelial tight junction permeability contributes to the severity of experimental DSS colitis.

    Science.gov (United States)

    Nighot, Prashant; Al-Sadi, Rana; Rawat, Manmeet; Guo, Shuhong; Watterson, D Martin; Ma, Thomas

    2015-12-15

    Recent studies have implicated a pathogenic role for matrix metalloproteinases 9 (MMP-9) in inflammatory bowel disease. Although loss of epithelial barrier function has been shown to be a key pathogenic factor for the development of intestinal inflammation, the role of MMP-9 in intestinal barrier function remains unclear. The aim of this study was to investigate the role of MMP-9 in intestinal barrier function and intestinal inflammation. Wild-type (WT) and MMP-9(-/-) mice were subjected to experimental dextran sodium sulfate (DSS) colitis by administration of 3% DSS in drinking water for 7 days. The mouse colonic permeability was measured in vivo by recycling perfusion of the entire colon using fluorescently labeled dextran. The DSS-induced increase in the colonic permeability was accompanied by an increase in intestinal epithelial cell MMP-9 expression in WT mice. The DSS-induced increase in intestinal permeability and the severity of DSS colitis was found to be attenuated in MMP-9(-/-) mice. The colonic protein expression of myosin light chain kinase (MLCK) and phospho-MLC was found to be significantly increased after DSS administration in WT mice but not in MMP-9(-/-) mice. The DSS-induced increase in colonic permeability and colonic inflammation was attenuated in MLCK(-/-) mice and MLCK inhibitor ML-7-treated WT mice. The DSS-induced increase in colonic surface epithelial cell MLCK mRNA was abolished in MMP-9(-/-) mice. Lastly, increased MMP-9 protein expression was detected within the colonic surface epithelial cells in ulcerative colitis cases. These data suggest a role of MMP-9 in modulation of colonic epithelial permeability and inflammation via MLCK.

  11. Matrix metalloproteinase 9-induced increase in intestinal epithelial tight junction permeability contributes to the severity of experimental DSS colitis

    Science.gov (United States)

    Nighot, Prashant; Al-Sadi, Rana; Guo, Shuhong; Watterson, D. Martin; Ma, Thomas

    2015-01-01

    Recent studies have implicated a pathogenic role for matrix metalloproteinases 9 (MMP-9) in inflammatory bowel disease. Although loss of epithelial barrier function has been shown to be a key pathogenic factor for the development of intestinal inflammation, the role of MMP-9 in intestinal barrier function remains unclear. The aim of this study was to investigate the role of MMP-9 in intestinal barrier function and intestinal inflammation. Wild-type (WT) and MMP-9−/− mice were subjected to experimental dextran sodium sulfate (DSS) colitis by administration of 3% DSS in drinking water for 7 days. The mouse colonic permeability was measured in vivo by recycling perfusion of the entire colon using fluorescently labeled dextran. The DSS-induced increase in the colonic permeability was accompanied by an increase in intestinal epithelial cell MMP-9 expression in WT mice. The DSS-induced increase in intestinal permeability and the severity of DSS colitis was found to be attenuated in MMP-9−/− mice. The colonic protein expression of myosin light chain kinase (MLCK) and phospho-MLC was found to be significantly increased after DSS administration in WT mice but not in MMP-9−/− mice. The DSS-induced increase in colonic permeability and colonic inflammation was attenuated in MLCK−/− mice and MLCK inhibitor ML-7-treated WT mice. The DSS-induced increase in colonic surface epithelial cell MLCK mRNA was abolished in MMP-9−/− mice. Lastly, increased MMP-9 protein expression was detected within the colonic surface epithelial cells in ulcerative colitis cases. These data suggest a role of MMP-9 in modulation of colonic epithelial permeability and inflammation via MLCK. PMID:26514773

  12. Three-Dimensional Organotypic Co-Culture Model of Intestinal Epithelial Cells and Macrophages to Study "Salmonella Enterica" Colonization Patterns

    Science.gov (United States)

    Ott, Mark; Yang, J; Barilla, J.; Crabbe, A.; Sarker, S. F.; Liu, Y.

    2017-01-01

    Three-dimensional/3-D organotypic models of human intestinal epithelium mimic the differentiated form and function of parental tissues often not exhibited by 2-D monolayers and respond to Salmonella in ways that reflect in vivo infections. To further enhance the physiological relevance of 3-D models to more closely approximate in vivo intestinal microenvironments during infection, we developed and validated a novel 3-D intestinal co-culture model containing multiple epithelial cell types and phagocytic macrophages, and applied to study enteric infection by different Salmonella pathovars.

  13. Coating with luminal gut-constituents alters adherence of nanoparticles to intestinal epithelial cells

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    Heike Sinnecker

    2014-12-01

    Full Text Available Background: Anthropogenic nanoparticles (NPs have found their way into many goods of everyday life. Inhalation, ingestion and skin contact are potential routes for NPs to enter the body. In particular the digestive tract with its huge absorptive surface area provides a prime gateway for NP uptake. Considering that NPs are covered by luminal gut-constituents en route through the gastrointestinal tract, we wanted to know if such modifications have an influence on the interaction between NPs and enterocytes.Results: We investigated the consequences of a treatment with various luminal gut-constituents on the adherence of nanoparticles to intestinal epithelial cells. Carboxylated polystyrene particles 20, 100 and 200 nm in size represented our anthropogenic NPs, and differentiated Caco-2 cells served as model for mature enterocytes of the small intestine. Pretreatment with the proteins BSA and casein consistently reduced the adherence of all NPs to the cultured enterocytes, while incubation of NPs with meat extract had no obvious effect on particle adherence. In contrast, contact with intestinal fluid appeared to increase the particle-cell interaction of 20 and 100 nm NPs.Conclusion: Luminal gut-constituents may both attenuate and augment the adherence of NPs to cell surfaces. These effects appear to be dependent on the particle size as well as on the type of interacting protein. While some proteins will rather passivate particles towards cell attachment, possibly by increasing colloid stability or camouflaging attachment sites, certain components of intestinal fluid are capable to modify particle surfaces in such a way that interactions with cellular surface structures result in an increased binding.

  14. Deficiency in macrophage-stimulating protein results in spontaneous intestinal inflammation and increased susceptibility toward epithelial damage in zebrafish.

    Science.gov (United States)

    Witte, Merlijn; Huitema, Leonie F A; Nieuwenhuis, Edward E S; Brugman, Sylvia

    2014-12-01

    Several genome-wide association studies have identified the genes encoding for macrophage-stimulating protein (MSP) and its receptor RON (Recepteur d'Origine Nantais) as possible susceptibility factors in inflammatory bowel disease. While it has been shown that the MSP-RON signaling pathway is involved in tissue injury responses, current mouse models for MSP and RON deficiency have not clearly demonstrated a role of MSP-RON signaling in the context of intestinal inflammation. In this study, we report that the recently identified zebrafish Msp mutant (msp(t34230)) develops spontaneous intestinal inflammation over time. From 14 to 28 weeks postfertilization Msp-deficient zebrafish show intestinal eosinophilia, increased intestinal expression of inflammatory marker mmp9, and activation of intestinal goblet cells. Moreover, these Msp mutant zebrafish are more susceptible toward ethanol-induced epithelial damage, which resulted in increased infiltration and proliferation of immune cells within the lamina propria and prolonged intestinal proinflammatory cytokine responses in some mutant fish. In light of the recent development of many tools to visualize, monitor, and genetically modify zebrafish, these Msp-deficient zebrafish will enable in-depth in vivo analysis of epithelial and macrophage-specific MSP-RON signaling in the context of intestinal inflammation.

  15. Preterm as compared with full-term neonatal calves are characterized by morphological and functional immaturity of the small intestine.

    Science.gov (United States)

    Bittrich, S; Philipona, C; Hammon, H M; Romé, V; Guilloteau, P; Blum, J W

    2004-06-01

    Intestinal diseases in neonatal calves may be due to morphological and functional immaturity. We have studied histomorphology, crypt cell proliferation rates (based on incorporation of 5-bromo-2'-deoxyuridine into DNA), presence of apoptotic cells (based on terminal deoxynucleotidyl transferase-mediated X-dUTP nick end labeling), and brush border enzyme activities in preterm calves (277 d of gestation), euthanized on d 1 (P0) or 8 (P8), and in full-term calves (290 d of gestation), euthanized on d 1 (F0) or 8 (F8). Vacuolated epithelial cells were present in ileum of P0 and F0 but not in P8 and F8. During the first 8 d, villus sizes, crypt depths, and proliferation rates of crypt cells in the small intestine of preterm calves did not significantly change. In contrast, in full-term calves during the first 8 d, villus sizes in jejunum decreased, crypt depths increased in small intestine and colon, and crypt cell proliferation increased in duodenum and jejunum. Submucosal thickness in jejunum was highest in P0, but in ileum it increased with gestational age and feeding. Gestational age x feeding interactions indicated increased activities of aminopeptidase N and reduced lactase activities only in F8 and reduced dipeptidylpeptidase IV activities only in P8. In conclusion, in preterm calves the small intestinal epithelium was immature and brush border enzyme activities differed in part from those in full-term calves.

  16. DHA protects against experimental colitis in IL-10-deficient mice associated with the modulation of intestinal epithelial barrier function.

    Science.gov (United States)

    Zhao, Jie; Shi, Peiliang; Sun, Ye; Sun, Jing; Dong, Jian-Ning; Wang, Hong-Gang; Zuo, Lu-Gen; Gong, Jian-Feng; Li, Yi; Gu, Li-Li; Li, Ning; Li, Jie-Shou; Zhu, Wei-Ming

    2015-07-01

    A defect in the intestinal barrier is one of the characteristics of Crohn's disease (CD). The tight junction (TJ) changes and death of epithelial cells caused by intestinal inflammation play an important role in the development of CD. DHA, a long-chain PUFA, has been shown to be helpful in treating inflammatory bowel disease in experimental models by inhibiting the NF-κB pathway. The present study aimed at investigating the specific effect of DHA on the intestinal barrier function in IL-10-deficient mice. IL-10-deficient mice (IL-10(-/-)) at 16 weeks of age with established colitis were treated with DHA (i.g. 35.5 mg/kg per d) for 2 weeks. The severity of their colitis, levels of pro-inflammatory cytokines, epithelial gene expression, the distributions of TJ proteins (occludin and zona occludens (ZO)-1), and epithelial apoptosis in the proximal colon were measured at the end of the experiment. DHA treatment attenuated the established colitis and was associated with reduced infiltration of inflammatory cells in the colonic mucosa, lower mean histological scores and decreased levels of pro-inflammatory cytokines (IL-17, TNF-α and interferon-γ). Moreover, enhanced barrier function was observed in the DHA-treated mice that resulted from attenuated colonic permeability, rescued expression and corrected distributions of occludin and ZO-1. The results of the present study indicate that DHA therapy may ameliorate experimental colitis in IL-10(-/-) mice by improving the intestinal epithelial barrier function.

  17. Localized intestinal radiation and liquid diet enhance survival and permit evaluation of long-term intestinal responses to high dose radiation in mice.

    Directory of Open Access Journals (Sweden)

    Laurianne Van Landeghem

    Full Text Available BACKGROUND: In vivo studies of high dose radiation-induced crypt and intestinal stem cell (ISC loss and subsequent regeneration are typically restricted to 5-8 days after radiation due to high mortality and immune failure. This study aimed to develop murine radiation models of complete crypt loss that permit longer-term studies of ISC and crypt regeneration, repair and normalization of the intestinal epithelium. METHODS: In C57Bl/6J mice, a predetermined small intestinal segment was exteriorized and exposed to 14 Gy-radiation, while a lead shield protected the rest of the body from radiation. Sham controls had segment exteriorization but no radiation. Results were compared to C57Bl/6J mice given 14 Gy-abdominal radiation. Effects of elemental liquid diet feeding from the day prior to radiation until day 7 post-radiation were assessed in both models. Body weight and a custom-developed health score was assessed every day until day 21 post-radiation. Intestine was assessed histologically. RESULTS: At day 3 after segment radiation, complete loss of crypts occurred in the targeted segment, while adjacent and remaining intestine in segment-radiated mice, and entire intestine of sham controls, showed no detectable epithelial damage. Liquid diet feeding was required for survival of mice after segment radiation. Liquid diet significantly improved survival, body weight recovery and normalization of intestinal epithelium after abdominal radiation. Mice given segment radiation combined with liquid diet feeding showed minimal body weight loss, increased food intake and enhanced health score. CONCLUSIONS: The segment radiation method provides a useful model to study ISC/crypt loss and long-term crypt regeneration and epithelial repair, and may be valuable for future application to ISC transplantation or to genetic mutants that would not otherwise survive radiation doses that lead to complete crypt loss. Liquid diet is a simple intervention that improves

  18. A gene expression programme induced by bovine colostrum whey promotes growth and wound-healing processes in intestinal epithelial cells.

    Science.gov (United States)

    Blais, M; Pouliot, Y; Gauthier, S; Boutin, Y; Lessard, M

    2014-01-01

    Bovine colostrum is well known for its beneficial properties on health and development. It contains a wide variety of bioactive ingredients that are known to promote a number of cellular processes. Therefore the use of colostrum whey as a feed additive to promote intestinal health has been proposed, yet little is known about mechanisms implicated in its beneficial properties on intestinal epithelial cells. In the present paper, casein were removed from bovine colostrum and the remaining liquid, rich in bioactive compounds, was evaluated for its capacity to modulate cellular processes in porcine intestinal epithelial cell line IPEC-J2 and human colon adenocarcinoma cell line Caco-2/15. First, we verified the effect of colostrum whey and cheese whey on processes involved in intestinal wound healing, including cell proliferation, attachment, morphology and migration. Our results showed that colostrum whey promoted proliferation and migration, and decreased specifically the attachment of Caco-2/15 cells on the culture dish. On the other hand, cheese whey induced proliferation and morphological changes in IPEC-J2 cells, but failed to induce migration. The gene expression profile of IPEC-J2 cells following colostrum whey treatment was evaluated by microarray analysis. Results revealed that the expression of a significant number of genes involved in cell migration, adhesion and proliferation was indeed affected in colostrum whey-treated cells. In conclusion, colostrum specific bioactive content could be beneficial for intestinal epithelial cell homoeostasis by controlling biological processes implicated in wound healing through a precise gene expression programme.

  19. Primary culture of intestinal epithelial cells as a potential model for Toxoplasma gondii enteric cycle studies

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    Marcos de Assis Moura

    2009-09-01

    Full Text Available The primary culture of intestinal epithelial cells from domestic cats is an efficient cellular model to study the enteric cycle of Toxoplasma gondii in a definitive host. The parasite-host cell ratio can be pointed out as a decisive factor that determines the intracellular fate of bradyzoites forms. The development of the syncytial-like forms of T. gondii was observed using the 1:20 bradyzoite-host cell ratio, resulting in similar forms described in in vivo systems. This alternative study potentially opens up the field for investigation into the molecular aspects of this interaction. This can contribute to the development of new strategies for intervention of a main route by which toxoplasmosis spreads.

  20. Processing of whey modulates proliferative and immune functions in intestinal epithelial cells

    DEFF Research Database (Denmark)

    Nguyen, Duc Ninh; Sangild, Per Torp; Li, Yanqi

    2016-01-01

    Whey protein concentrate (WPC) is often subjected to heat treatment during industrial processing, resulting in protein denaturation and loss of protein bioactivity. We hypothesized that WPC samples subjected to different degrees of thermal processing are associated with different levels...... from acid whey or low-heat-treated WPC from sweet whey. Following acid activation (to activate growth factors), low-heat-treated WPC from sweet whey induced higher IL-8 levels in IEC compared with standard WPC from sweet whey. In conclusion, higher levels of bioactive proteins in low-heat-treated WPC...... of bioactive proteins and effects on proliferation and immune response in intestinal epithelial cells (IEC). The results showed that low-heat-treated WPC had elevated levels of lactoferrin and transforming growth factor-β2 compared with that of standard WPC. The level of aggregates depended on the source...

  1. Methionine deficiency reduces autophagy and accelerates death in intestinal epithelial cells infected with enterotoxigenic Escherichia coli.

    Science.gov (United States)

    Tang, Yulong; Tan, Bie; Xiong, Xia; Li, Fengna; Ren, Wenkai; Kong, Xiangfeng; Qiu, Wei; Hardwidge, Philip R; Yin, Yulong

    2015-10-01

    Infections by enterotoxigenic Escherichia coli (ETEC) result in large economic losses to the swine industry worldwide. Dietary supplementation with amino acids has been considered as a potential mechanism to improve host defenses against infection. The goal of this study was to determine whether methionine deprivation alters ETEC interactions with porcine intestinal epithelial cells. IPEC-1 cells were cultured in media with or without L-methionine. Methionine deprivation resulted in enhanced ETEC adhesion and increased both the cytotoxicity and apoptotic responses of IPEC-1 cells infected with ETEC. Methionine deprivation inhibited IPEC-1 cell autophagic responses, suggesting that the increased cytotoxicity of ETEC to methionine-deprived IPEC-1 cells might be due to defects in autophagy.

  2. Fibroblast growth factor receptor-3 (FGFR-3) regulates expression of paneth cell lineage-specific genes in intestinal epithelial cells through both TCF4/beta-catenin-dependent and -independent signaling pathways.

    Science.gov (United States)

    Brodrick, Brooks; Vidrich, Alda; Porter, Edith; Bradley, Leigh; Buzan, Jenny M; Cohn, Steven M

    2011-05-27

    Fibroblast growth factor receptor-3 (FGFR-3) expression in the developing intestine is restricted to the undifferentiated epithelial cells within the lower portion of the crypt. We previously showed that mice lacking functional FGFR-3 have a significant decrease in the number of Paneth cells in the small intestine. Here, we used Caco2 cells to investigate whether FGFR-3 signaling can directly modulate expression of Paneth cell differentiation markers through its effects on TCF4/β-catenin or through other signaling pathways downstream of this receptor. Caco2 cells treated with FGFR-3 ligands or expressing FGFR-3(K650E), a constitutively active mutant, resulted in a significantly increased expression of genes characteristic of mature Paneth cells, including human α-defensins 5 and 6 (HD5 and HD6) and Paneth cell lysozyme, whereas enterocytic differentiation markers were reduced. Activation of FGFR-3 signaling sustained high levels of β-catenin mRNA expression, leading to increased TCF4/β-catenin-regulated transcriptional activity in Caco2 cells. Sustained activity of the TCF4/β-catenin pathway was required for the induction of Paneth cell markers. Activation of the MAPK pathway by FGFR-3 is also required for the induction of Paneth cell markers in addition to and independent of the effect of FGFR-3 on TCF4/β-catenin activity. These studies suggest that coordinate activation of multiple independent signaling pathways downstream of FGFR-3 is involved in regulation of Paneth cell differentiation.

  3. Transport and uptake effects of marine complex lipid liposomes in small intestinal epithelial cell models.

    Science.gov (United States)

    Du, Lei; Yang, Yu-Hong; Xu, Jie; Wang, Yu-Ming; Xue, Chang-Hu; Kurihara, Hideyuki; Takahashi, Koretaro

    2016-04-01

    Nowadays, marine complex lipids, including starfish phospholipids (SFP) and cerebrosides (SFC) separated from Asterias amurensis as well as sea cucumber phospholipids (SCP) and cerebrosides (SCC) isolated from Cucumaria frondosa, have received much attention because of their potent biological activities. However, little information is known on the transport and uptake of these lipids in liposome forms in small intestinal cells. Therefore, this study was undertaken to investigate the effects of these complex lipid liposomes on transport and uptake in Caco-2 and M cell monolayer models. The results revealed that SFP and SCP contained 42% and 47.9% eicosapentaenoic acid (EPA), respectively. The average particle sizes of liposomes prepared in this study were from 169 to 189 nm. We found that the transport of the liposomes across the M cell monolayer model was much higher than the Caco-2 cell monolayer model. The liposomes consisting of SFP or SCP showed significantly higher transport and uptake than soy phospholipid (soy-PL) liposomes in both Caco-2 and M cell monolayer models. Our results also exhibited that treatment with 1 mM liposomes composed of SFP or SCP for 3 h tended to increase the EPA content in phospholipid fractions of both differentiated Caco-2 and M cells. Moreover, it was also found that the hybrid liposomes consisting of SFP/SFC/cholesterol (Chol) revealed higher transport and uptake across the M cell monolayer in comparison with other liposomes. Furthermore, treatment with SFP/SFC/Chol liposomes could notably decrease the trans-epithelial electrical resistance (TEER) values of Caco-2 and M cell monolayers. The present data also showed that the cell viability of differentiated Caco-2 and M cells was not affected after the treatment with marine complex lipids or soy-PL liposomes. Based on the data in this study, it was suggested that marine complex lipid liposomes exhibit prominent transport and uptake in small intestinal epithelial cell models.

  4. The Critical Role of Membrane Cholesterol in Salmonella-Induced Autophagy in Intestinal Epithelial Cells

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    Fu-Chen Huang

    2014-07-01

    Full Text Available It was previously observed that plasma membrane cholesterol plays a critical role in the Salmonella-induced phosphatidylinositol 3-kinase-dependent (PI3K-dependent anti-inflammatory response in intestinal epithelial cells (IECs. The PI3K/Akt pathway is associated with autophagy which has emerged as a critical mechanism of host defense against several intracellular bacterial pathogens. Plasma membrane contributes directly to the formation of early Atg16L1-positive autophagosome precursors. Therefore, this study aimed to investigate the role of plasma membrane cholesterol on the Salmonella-induced autophagy in IECs. By using methyl-beta-cyclodextrin (MBCD, it was demonstrated that disruption of membrane cholesterol by MBCD enhanced NOD2 and Atg16L1 proteins expression in membrane, and autophagic LC3II proteins expression and LC3 punctae in Salmonella-infected Caco-2 cells, which was counteracted by Atg16L1 siRNA. Nucleotide-binding oligomerization domain-containing protein 2 (NOD2 siRNA enhanced the Salmonella-induced activation of Akt in Caco-2 cells. However, inhibitors of Akt or extracellular signal-regulated kinases (ERK had no significant effect on Salmonella-induced autophagy Beclin 1 or LC3 proteins expression. In conclusion, our study suggests that cholesterol accumulation in the plasma membrane at the entry site of Salmonella results in the formation of Salmonella-containing vacuole (SCV and decreased autophagy. Our results offer mechanistic insights on the critical role of membrane cholesterol in the pathogenesis of Salmonella infection in intestinal epithelial cells and the therapeutic potential of its antagonists.

  5. Fusion between Intestinal epithelial cells and macrophages in a cancer context results in nuclear reprogramming.

    Science.gov (United States)

    Powell, Anne E; Anderson, Eric C; Davies, Paige S; Silk, Alain D; Pelz, Carl; Impey, Soren; Wong, Melissa H

    2011-02-15

    The most deadly phase in cancer progression is attributed to the inappropriate acquisition of molecular machinery leading to metastatic transformation and spread of disease to distant organs. Although it is appreciated that metastasis involves epithelial-mesenchymal interplay, the underlying mechanism defining this process is poorly understood. Specifically, how cancer cells evade immune surveillance and gain the ability to navigate the circulatory system remains a focus. One possible mechanism underlying metastatic conversion is fusion between blood-derived immune cells and cancer cells. While this notion is a century old, in vivo evidence that cell fusion occurs within tumors and imparts genetic or physiologic changes remains controversial. We have previously demonstrated in vivo cell fusion between blood cells and intestinal epithelial cells in an injury setting. Here, we hypothesize that immune cells, such as macrophages, fuse with tumor cells imparting metastatic capabilities by transferring their cellular identity. We used parabiosis to introduce fluorescent-labeled bone marrow-derived cells to mice with intestinal tumors, finding that fusion between circulating blood-derived cells and tumor epithelium occurs during the natural course of tumorigenesis. Moreover, we identify the macrophage as a key cellular partner for this process. Interestingly, cell fusion hybrids retain a transcriptome identity characteristic of both parental derivatives, while also expressing a unique subset of transcripts. Our data supports the novel possibility that tumorigenic cell fusion may impart physical behavior attributed to migratory macrophages, including navigation of circulation and immune evasion. As such, cell fusion may represent a promising novel mechanism underlying the metastatic conversion of cancer cells.

  6. Inflammatory cytokine TNF-α inhibits Na(+)-glutamine cotransport in intestinal epithelial cells.

    Science.gov (United States)

    Talukder, Jamilur R; Boyd, Brittney; Griffin, Ashley; Jaima, Antara; Rajendran, Vazhaikkurichi M

    2013-04-01

    Glutamine (Gln), a preferred fuel source for enterocytes, is critical for intestinal epithelial cell integrity and barrier function. Chronic enteritis inhibits apical Na(+)-Gln cotransport. It is not known whether inflammatory cytokines that are secreted during inflammation inhibit Na(+)-Gln cotransport. Thus, this study aimed to examine whether TNF-α would affect apical Na(+)-Gln cotransport in intestinal epithelial cells. In this study, the presence of Na(+)-Gln cotransport was established by measuring Gln uptake in 10 days postconfluent IEC-6 cells grown on transwell plates. Cation, amino acid specificity, and siRNA transfection studies established that Na(+)-Gln cotransport is mediated via B(0)AT1. Immunoblotting and immunofluorescence studies established the apical membrane localization of B(0)AT1 in IEC-6 cells. Tumour necrosis factor α (TNF-α) inhibited Na(+)-Gln cotransport in a concentration- and time-dependent manner with an inhibitory concentration of 1.53 nmol·L(-1). Quantitative real-time PCR and Western blot analyses indicated that TNF-α did not alter B(0)AT1-specific transcripts or protein expression level. Kinetic studies revealed that TNF-α inhibited Na(+)-Gln cotransport by reducing the affinity of the cotransporters for Gln, and this effect was antagonized by genistein. Thus, we conclude that the TNF-α inhibition of Na(+)-Gln cotransport occurs at the post-translational level, and that the IEC-6 cell line is an excellent system to study the role of cytokines in Na(+)-Gln cotransport.

  7. Use of micro-optical coherence tomography to analyze barrier integrity of intestinal epithelial cells (Conference Presentation)

    Science.gov (United States)

    Som, Avira; Leung, Hui Min; Chu, Kengyeh; Eaton, Alex D.; Hurley, Bryan P.; Tearney, Guillermo J.

    2017-02-01

    The intestinal epithelial barrier provides protection from external threats that enter the digestive system and persist beyond passage through the stomach. The effects of toxic agents on the intestinal epithelial cell monolayer have not been fully characterized at a cellular level as live imaging of this dynamic interplay at sufficient resolution to interpret cellular responses presents technological challenges. Using a high-resolution native contrast modality called Micro-Optical Coherence Tomography (μOCT), we generated real-time 3D images depicting the impact of the chemical agent EDTA on polarized intestinal epithelial monolayers. Within minutes following application of EDTA, we observed a change in the uniformity of epithelial surface thickness and loss of the edge brightness associated with the apical surface. These observations were measured by generating computer algorithms which quantify imaged-based events changing over time, thus providing parallel graphed data to pair with video. The imaging platform was designed to monitor epithelial monolayers prior to and following application of chemical agents in order to provide a comprehensive account of monolayer behavior at baseline conditions and immediately following exposure. Furthermore, the platform was designed to simultaneously measure continuous trans-epithelial electric resistance (TEER) in order to define the progressive loss of barrier integrity of the cell monolayer following exposure to toxic agents and correlate these findings to image-based metrics. This technological image-based experimental platform provides a novel means to characterize mechanisms that impact the intestinal barrier and, in future efforts, can be applied to study the impact of disease relevant agents such as enteric pathogens and enterotoxins.

  8. Intestinal Epithelial Serum Amyloid A Modulates Bacterial Growth In Vitro and Pro-Inflammatory Responses in Mouse Experimental Colitis

    Directory of Open Access Journals (Sweden)

    Wang Yu

    2010-11-01

    Full Text Available Abstract Background Serum Amyloid A (SAA is a major acute phase protein of unknown function. SAA is mostly expressed in the liver, but also in other tissues including the intestinal epithelium. SAA reportedly has anti-bacterial effects, and because inflammatory bowel diseases (IBD result from a breakdown in homeostatic interactions between intestinal epithelia and bacteria, we hypothesized that SAA is protective during experimental colitis. Methods Intestinal SAA expression was measured in mouse and human samples. Dextran sodium sulfate (DSS colitis was induced in SAA 1/2 double knockout (DKO mice and in wildtype controls. Anti-bacterial effects of SAA1/2 were tested in intestinal epithelial cell lines transduced with adenoviral vectors encoding the CE/J SAA isoform or control vectors prior to exposure to live Escherichia coli. Results Significant levels of SAA1/SAA2 RNA and SAA protein were detected by in situ hybridization and immunohistochemistry in mouse colonic epithelium. SAA3 expression was weaker, but similarly distributed. SAA1/2 RNA was present in the ileum and colon of conventional mice and in the colon of germfree mice. Expression of SAA3 was strongly regulated by bacterial lipopolysaccharides in cultured epithelial cell lines, whereas SAA1/2 expression was constitutive and not LPS inducible. Overexpression of SAA1/2 in cultured epithelial cell lines reduced the viability of co-cultured E. coli. This might partially explain the observed increase in susceptibility of DKO mice to DSS colitis. SAA1/2 expression was increased in colon samples obtained from Crohn's Disease patients compared to controls. Conclusions Intestinal epithelial SAA displays bactericidal properties in vitro and could play a protective role in experimental mouse colitis. Altered expression of SAA in intestinal biopsies from Crohn's Disease patients suggests that SAA is involved in the disease process..

  9. E. coli Nissle 1917 Affects Salmonella adhesion to porcine intestinal epithelial cells.

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    Peter Schierack

    Full Text Available BACKGROUND: The probiotic Escherichia coli strain Nissle 1917 (EcN has been shown to interfere in a human in vitro model with the invasion of several bacterial pathogens into epithelial cells, but the underlying molecular mechanisms are not known. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we investigated the inhibitory effects of EcN on Salmonella Typhimurium invasion of porcine intestinal epithelial cells, focusing on EcN effects on the various stages of Salmonella infection including intracellular and extracellular Salmonella growth rates, virulence gene regulation, and adhesion. We show that EcN affects the initial Salmonella invasion steps by modulating Salmonella virulence gene regulation and Salmonella SiiE-mediated adhesion, but not extra- and intracellular Salmonella growth. However, the inhibitory activity of EcN against Salmonella invasion always correlated with EcN adhesion capacities. EcN mutants defective in the expression of F1C fimbriae and flagellae were less adherent and less inhibitory toward Salmonella invasion. Another E. coli strain expressing F1C fimbriae was also adherent to IPEC-J2 cells, and was similarly inhibitory against Salmonella invasion like EcN. CONCLUSIONS: We propose that EcN affects Salmonella adhesion through secretory components. This mechanism appears to be common to many E. coli strains, with strong adherence being a prerequisite for an effective reduction of SiiE-mediated Salmonella adhesion.

  10. In Vitro intestinal mucosal epithelial responses to wild-typeSalmonella Typhi and attenuated typhoid vaccines

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    Maria eFiorentino

    2013-02-01

    Full Text Available Typhoid fever, caused by S. Typhi, is responsible for approximately 200,000 deaths per year worldwide. Little information is available regarding epithelium-bacterial interactions in S. Typhi infection. We have evaluated in vitro the effects of wild-type S. Typhi, the licensed Ty21a typhoid vaccine and the leading strains CVD 908-htrA and CVD 909 vaccine candidates on intestinal barrier function and immune response. Caco2 monolayers infected with wild-type S. Typhi exhibited alterations in the organization of tight junctions, increased paracellular permeability, and a rapid decrease in Trans-Epithelial Electrical Resistance as early as 4h post-exposure. S. Typhi triggered the secretion of interleukin (IL-8 and IL-6. Caco2 cells infected with the attenuated strains exhibited a milder pro-inflammatory response with minimal disruption of the barrier integrity. We conclude that wild-type S. Typhi causes marked transient alterations of the intestinal mucosa that are more pronounced than those observed with Ty21a or new generation attenuated typhoid vaccine candidates.

  11. Profiles of microRNA networks in intestinal epithelial cells in a mouse model of colitis.

    Science.gov (United States)

    Lee, Juneyoung; Park, Eun Jeong; Yuki, Yoshikazu; Ahmad, Shandar; Mizuguchi, Kenji; Ishii, Ken J; Shimaoka, Motomu; Kiyono, Hiroshi

    2015-12-09

    Inflammatory bowel diseases (IBDs) accompany a critical loss of the frontline barrier function that is achieved primarily by intestinal epithelial cells (IECs). Although the gene-regulation pathways underlying these host-defense roles of IECs presumably are deranged during IBD pathogenesis, the quantitative and qualitative alterations of posttranscriptional regulators such as microRNAs (miRNAs) within the cells largely remain to be defined. We aimed to uncover the regulatory miRNA-target gene relationships that arise differentially in inflamed small- compared with large-IECs. Whereas IBD significantly increased the expression of only a few miRNA candidates in small-IECs, numerous miRNAs were upregulated in inflamed large-IECs. These marked alterations might explain why the large, as compared with small, intestine is more sensitive to colitis and shows more severe pathology in this experimental model of IBD. Our in-depth assessment of the miRNA-mRNA expression profiles and the resulting networks prompts us to suggest that miRNAs such as miR-1224, miR-3473a, and miR-5128 represent biomarkers that appear in large-IECs upon IBD development and co-operatively repress the expression of key anti-inflammatory factors. The current study provides insight into gene-regulatory networks in IECs through which dynamic rearrangement of the involved miRNAs modulates the gene expression-regulation machinery between maintaining and disrupting gastrointestinal homeostasis.

  12. Transepithelial transport of putrescine across monolayers of the human intestinal epithelial cell line, Caco-2

    Institute of Scientific and Technical Information of China (English)

    Vladan Milovic; Lyudmila Turchanowa; Jurgen Stein; Wolfgang F. Caspary

    2001-01-01

    AIM To study the transepithelial transport characteristics of the polyamine putrescine in human intestinal Caco-2 cell monolayers to elucidate the mechanisms of the putrescine intestinal absorption.METHODS The transepithelial transport and the cellular accumulation of putrescine was measured using Caco 2 cell monolayers grown on permeable filters.RESULTS Transepithelial transport of putrescine in physiological concentrations (>0.5 mM)from the apical to basolateral side was linear. Intracellular accumulation of putrescine was higher in confluent than in fully differentiated Caco-2 cells, but still negligible (less than 0.5%) of the overall transport across the monolayers in apical-to-basolateral direction. EGF enhanced putrescine accumulation in Caco-2 cells by four-fold, as well as putrescine conversion to spermidine and spermine by enhancing the activity of Sadenosylmethionine decarboxylase. However,EGF did not have any significant influence on putrescine flux across the Caco-2 cell monolayers. Excretion of putrescine from Caco-2cells into the basolateral medium did not exceed 50 picomoles, while putrescine passive flux from the apical to the basolateral chamber,contributed hundreds of micromoles polyamines to the basolateral chamber.CONCLUSION Transepithelial transport of putrescine across Caco-2 cell monolayers occurs in passive diffusion, and is not influenced when epithelial cells are stimulated to proliferate by a potent mitogen such as EGF.

  13. MDR1 is Related to Intestinal Epithelial Injury Induced by Acetylsalicylic Acid

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    Munehiro Kugai

    2013-10-01

    Full Text Available Background/Aims: Although the cytotoxicity of aspirin against the intestinal epithelium is a major clinical problem, little is known about its pathogenesis. We assessed the involvement of Multi Drug Resistance (MDR 1 in intestinal epithelial cell injury caused by aspirin using MDR1 gene-transfected Caco2 cells. Methods: Caco2 cells were treated with various concentrations of aspirin for 24 h. After treatment of Caco2 cells with verapamil, a specific inhibitor of MDR1, we assessed the extent of cell injury using a WST-8 assay at 24 h after aspirin-stimulation. We performed the same procedure in MDR1 gene-transfected Caco2 cells. To determine the function of MDR1 in the metabolism of aspirin, flux study was performed using 14C-labeled aspirin. Results: The level of aspirin-induced cell injury was higher in verapamil-treated Caco2 cells than in control cells and was less serious in MDR1-transfected Caco2 cells than in control vector-transfected cells. The efflux of 14C-labeled aspirin was higher in verapamil-treated Caco2 cells than in control cells. Conclusion: These data suggest that aspirin effux occurs through the MDR1 transporter and that the MDR1 transporter is involved in the pathogenesis of aspirin-induced cell injury.

  14. Intestinal barrier homeostasis in inflammatory bowel disease.

    Science.gov (United States)

    Goll, Rasmus; van Beelen Granlund, Atle

    2015-01-01

    The single-cell thick intestinal epithelial cell (IEC) lining with its protective layer of mucus is the primary barrier protecting the organism from the harsh environment of the intestinal lumen. Today it is clear that the balancing act necessary to maintain intestinal homeostasis is dependent on the coordinated action of all cell types of the IEC, and that there are no passive bystanders to gut immunity solely acting as absorptive or regenerative cells: Mucin and antimicrobial peptides on the epithelial surface are continually being replenished by goblet and Paneth's cells. Luminal antigens are being sensed by pattern recognition receptors on the enterocytes. The enteroendocrine cells sense the environment and coordinate the intestinal function by releasing neuropeptides acting both on IEC and inflammatory cells. All this while cells are continuously and rapidly being regenerated from a limited number of stem cells close to the intestinal crypt base. This review seeks to describe the cell types and structures of the intestinal epithelial barrier supporting intestinal homeostasis, and how disturbance in these systems might relate to inflammatory bowel disease.

  15. Visualization of probiotic-mediated Ca2+ signaling in intestinal epithelial cells in vivo

    Directory of Open Access Journals (Sweden)

    Takahiro Adachi

    2016-12-01

    Full Text Available Probiotics, such as lactic acid bacteria (LAB and Bacillus subtilis var. natto, have been shown to modulate immune responses. It is important to understand how probiotic bacteria impact intestinal epithelial cells (IECs, because IECs are the first line of defense at the mucosal surface barrier and their activities substantially affect the gut microenvironment and immunity. However, to date, their precise mechanism remains unknown due to a lack of analytical systems available for live animal models. Recently, we generated a conditional Ca2+ biosensor Yellow Cameleon (YC3.60 transgenic mouse line and established 5D (x, y, z, time, and Ca2+ intravital imaging systems of lymphoid tissues including those in Peyer’s patches and bone marrow. In the present study, we further advance our intravital imaging system for intestinal tracts to visualize IEC responses against orally administrated food compounds in real time. Using this system, heat-killed Bacillus subtilis natto, a probiotic TTCC012 strain, is shown to directly induce Ca2+ signaling in IECs in mice housed under specific pathogen-free conditions. In contrast, this activation is not observed in the Lactococcus lactis strain C60; however, when we generate germ-free YC3.60 mice and observe the LAB stimulation of IECs in the absence of gut microbiota, C60 is capable of inducing Ca2+ signaling. This is the first study to successfully visualize the direct effect of probiotics on IECs in live animals. These data strongly suggest that probiotic strains stimulate IECs under physiological conditions, and that their activity is affected by the microenvironment of the small intestine, such as commensal bacteria.

  16. Celiac Anti-Type 2 Transglutaminase Antibodies Induce Phosphoproteome Modification in Intestinal Epithelial Caco-2 Cells

    Science.gov (United States)

    Marabotti, Anna; Lepretti, Marilena; Salzano, Anna Maria; Scaloni, Andrea; Vitale, Monica; Zambrano, Nicola; Sblattero, Daniele; Esposito, Carla

    2013-01-01

    Background Celiac disease is an inflammatory condition of the small intestine that affects genetically predisposed individuals after dietary wheat gliadin ingestion. Type 2-transglutaminase (TG2) activity seems to be responsible for a strong autoimmune response in celiac disease, TG2 being the main autoantigen. Several studies support the concept that celiac anti-TG2 antibodies may contribute to disease pathogenesis. Our recent findings on the ability of anti-TG2 antibodies to induce a rapid intracellular mobilization of calcium ions, as well as extracellular signal-regulated kinase phosphorylation, suggest that they potentially act as signaling molecules. In line with this concept, we have investigated whether anti-TG2 antibodies can induce phosphoproteome modification in an intestinal epithelial cell line. Methods and Principal Findings We studied phosphoproteome modification in Caco-2 cells treated with recombinant celiac anti-TG2 antibodies. We performed a two-dimensional electrophoresis followed by specific staining of phosphoproteins and mass spectrometry analysis of differentially phosphorylated proteins. Of 14 identified proteins (excluding two uncharacterized proteins), three were hypophosphorylated and nine were hyperphosphorylated. Bioinformatics analyses confirmed the presence of phosphorylation sites in all the identified proteins and highlighted their involvement in several fundamental biological processes, such as cell cycle progression, cell stress response, cytoskeletal organization and apoptosis. Conclusions Identification of differentially phosphorylated proteins downstream of TG2-antibody stimulation suggests that in Caco-2 cells these antibodies perturb cell homeostasis by behaving as signaling molecules. We hypothesize that anti-TG2 autoantibodies may destabilize the integrity of the intestinal mucosa in celiac individuals, thus contributing to celiac disease establishment and progression. Since several proteins here identified in this study

  17. Visualization of Probiotic-Mediated Ca2+ Signaling in Intestinal Epithelial Cells In Vivo

    Science.gov (United States)

    Adachi, Takahiro; Kakuta, Shigeru; Aihara, Yoshiko; Kamiya, Tomonori; Watanabe, Yohei; Osakabe, Naomi; Hazato, Naoki; Miyawaki, Atsushi; Yoshikawa, Soichiro; Usami, Takako; Karasuyama, Hajime; Kimoto-Nira, Hiromi; Hirayama, Kazuhiro; Tsuji, Noriko M.

    2016-01-01

    Probiotics, such as lactic acid bacteria (LAB) and Bacillus subtilis var. natto, have been shown to modulate immune responses. It is important to understand how probiotic bacteria impact intestinal epithelial cells (IECs), because IECs are the first line of defense at the mucosal surface barrier and their activities substantially affect the gut microenvironment and immunity. However, to date, their precise mechanism remains unknown due to a lack of analytical systems available for live animal models. Recently, we generated a conditional Ca2+ biosensor Yellow Cameleon (YC3.60) transgenic mouse line and established 5D (x, y, z, time, and Ca2+) intravital imaging systems of lymphoid tissues including those in Peyer’s patches and bone marrow. In the present study, we further advance our intravital imaging system for intestinal tracts to visualize IEC responses against orally administrated food compounds in real time. Using this system, heat-killed B. subtilis natto, a probiotic TTCC012 strain, is shown to directly induce Ca2+ signaling in IECs in mice housed under specific pathogen-free conditions. In contrast, this activation is not observed in the Lactococcus lactis strain C60; however, when we generate germ-free YC3.60 mice and observe the LAB stimulation of IECs in the absence of gut microbiota, C60 is capable of inducing Ca2+ signaling. This is the first study to successfully visualize the direct effect of probiotics on IECs in live animals. These data strongly suggest that probiotic strains stimulate IECs under physiological conditions and that their activity is affected by the microenvironment of the small intestine, such as commensal bacteria. PMID:28018362

  18. Celiac anti-type 2 transglutaminase antibodies induce phosphoproteome modification in intestinal epithelial Caco-2 cells.

    Directory of Open Access Journals (Sweden)

    Gaetana Paolella

    Full Text Available BACKGROUND: Celiac disease is an inflammatory condition of the small intestine that affects genetically predisposed individuals after dietary wheat gliadin ingestion. Type 2-transglutaminase (TG2 activity seems to be responsible for a strong autoimmune response in celiac disease, TG2 being the main autoantigen. Several studies support the concept that celiac anti-TG2 antibodies may contribute to disease pathogenesis. Our recent findings on the ability of anti-TG2 antibodies to induce a rapid intracellular mobilization of calcium ions, as well as extracellular signal-regulated kinase phosphorylation, suggest that they potentially act as signaling molecules. In line with this concept, we have investigated whether anti-TG2 antibodies can induce phosphoproteome modification in an intestinal epithelial cell line. METHODS AND PRINCIPAL FINDINGS: We studied phosphoproteome modification in Caco-2 cells treated with recombinant celiac anti-TG2 antibodies. We performed a two-dimensional electrophoresis followed by specific staining of phosphoproteins and mass spectrometry analysis of differentially phosphorylated proteins. Of 14 identified proteins (excluding two uncharacterized proteins, three were hypophosphorylated and nine were hyperphosphorylated. Bioinformatics analyses confirmed the presence of phosphorylation sites in all the identified proteins and highlighted their involvement in several fundamental biological processes, such as cell cycle progression, cell stress response, cytoskeletal organization and apoptosis. CONCLUSIONS: Identification of differentially phosphorylated proteins downstream of TG2-antibody stimulation suggests that in Caco-2 cells these antibodies perturb cell homeostasis by behaving as signaling molecules. We hypothesize that anti-TG2 autoantibodies may destabilize the integrity of the intestinal mucosa in celiac individuals, thus contributing to celiac disease establishment and progression. Since several proteins here

  19. Lineage-specific expression of bestrophin-2 and bestrophin-4 in human intestinal epithelial cells.

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    Go Ito

    Full Text Available Intestinal epithelial cells (IECs regulate the absorption and secretion of anions, such as HCO3(- or Cl(-. Bestrophin genes represent a newly identified group of calcium-activated Cl(- channels (CaCCs. Studies have suggested that, among the four human bestrophin-family genes, bestrophin-2 (BEST2 and bestrophin-4 (BEST4 might be expressed within the intestinal tissue. Consistently, a study showed that BEST2 is expressed by human colonic goblet cells. However, their precise expression pattern along the gastrointestinal tract, or the lineage specificity of the cells expressing these genes, remains largely unknown. Here, we show that BEST2 and BEST4 are expressed in vivo, each in a distinct, lineage-specific manner, in human IECs. While BEST2 was expressed exclusively in colonic goblet cells, BEST4 was expressed in the absorptive cells of both the small intestine and the colon. In addition, we found that BEST2 expression is significantly down-regulated in the active lesions of ulcerative colitis, where goblet cells were depleted, suggesting that BEST2 expression is restricted to goblet cells under both normal and pathologic conditions. Consistently, the induction of goblet cell differentiation by a Notch inhibitor, LY411575, significantly up-regulated the expression of not BEST4 but BEST2 in MUC2-positive HT-29 cells. Conversely, the induction of absorptive cell differentiation up-regulated the expression of BEST4 in villin-positive Caco-2 cells. In addition, we found that the up- or down-regulation of Notch activity leads to the preferential expression of either BEST4 or BEST2, respectively, in LS174T cells. These results collectively confirmed that BEST2 and BEST4 could be added to the lineage-specific genes of humans IECs due to their abilities to clearly identify goblet cells of colonic origin and a distinct subset of absorptive cells, respectively.

  20. Intestinal anti-inflammatory activity of red wine extract: unveiling the mechanisms in colonic epithelial cells.

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    Nunes, Carla; Ferreira, Elisabete; Freitas, Víctor; Almeida, Leonor; Barbosa, Rui M; Laranjinha, João

    2013-02-26

    The development of new therapeutic approaches, combining efficacy and safety against intestinal inflammation, notably inflammatory bowel disease (IBD), has emerged as an important goal due to the significant side effects and the lack of effectiveness of standard current therapies. Recently, several studies described the health-promoting effects of red wine, including anti-inflammatory properties, but the molecular mechanisms underlying its beneficial role remain largely unknown. Red wine is rich in phenolic compounds and it has been suggested that the positive effect of red wine intake might be attributed not only to the antioxidant properties of these compounds but also to the modulation of signalling cascades in connection with physiological and pathophysiological conditions such as inflammatory processes. This study assesses the potential anti-inflammatory action of a red wine extract (RWE) enriched in polyphenols in a cellular model of intestinal inflammation using cytokines-stimulated HT-29 colon epithelial cells. RWE suppressed cytokines-induced IκB degradation and interleukin-8 production in a dose-dependent manner. Coherently, key inflammatory mediators downstream NF-κB activation; notably cyclooxygenase-2 and inducible nitric oxide synthase were maintained at low levels by RWE in the presence of the cytokines. Additionally, RWE inhibited both the increase of nitric oxide derived from iNOS and of protein tyrosine nitration, a biomarker of nitrosative stress that typically requires the reaction of nitric oxide with the superoxide radical. Taken together, the anti-inflammatory action of RWE, mechanistically supported by the modulation of cascades orchestrated by NF-κB and involving nitric oxide, suggests that RWE (a readily straightforward preparation when compared with the purification of specific compounds) may represent a simple and inexpensive therapeutic strategy in the context of intestinal inflammation.

  1. Small intestinal mucosa expression of putative chaperone fls485

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    Raupach Kerstin

    2010-03-01

    Full Text Available Abstract Background Maturation of enterocytes along the small intestinal crypt-villus axis is associated with significant changes in gene expression profiles. fls485 coding a putative chaperone protein has been recently suggested as a gene involved in this process. The aim of the present study was to analyze fls485 expression in human small intestinal mucosa. Methods fls485 expression in purified normal or intestinal mucosa affected with celiac disease was investigated with a molecular approach including qRT-PCR, Western blotting, and expression strategies. Molecular data were corroborated with several in situ techniques and usage of newly synthesized mouse monoclonal antibodies. Results fls485 mRNA expression was preferentially found in enterocytes and chromaffine cells of human intestinal mucosa as well as in several cell lines including Rko, Lovo, and CaCo2 cells. Western blot analysis with our new anti-fls485 antibodies revealed at least two fls485 proteins. In a functional CaCo2 model, an increase in fls485 expression was paralleled by cellular maturation stage. Immunohistochemistry demonstrated fls485 as a cytosolic protein with a slightly increasing expression gradient along the crypt-villus axis which was impaired in celiac disease Marsh IIIa-c. Conclusions Expression and synthesis of fls485 are found in surface lining epithelia of normal human intestinal mucosa and deriving epithelial cell lines. An interdependence of enterocyte differentiation along the crypt-villus axis and fls485 chaperone activity might be possible.

  2. Small intestinal mucosa expression of putative chaperone fls485.

    Science.gov (United States)

    Reinartz, Andrea; Ehling, Josef; Franz, Susanne; Simon, Verena; Bravo, Ignacio G; Tessmer, Claudia; Zentgraf, Hanswalter; Lyer, Stefan; Schneider, Ursula; Köster, Jan; Raupach, Kerstin; Kämmerer, Elke; Klaus, Christina; Tischendorf, Jens J W; Kopitz, Jürgen; Alonso, Angel; Gassler, Nikolaus

    2010-03-07

    Maturation of enterocytes along the small intestinal crypt-villus axis is associated with significant changes in gene expression profiles. fls485 coding a putative chaperone protein has been recently suggested as a gene involved in this process. The aim of the present study was to analyze fls485 expression in human small intestinal mucosa. fls485 expression in purified normal or intestinal mucosa affected with celiac disease was investigated with a molecular approach including qRT-PCR, Western blotting, and expression strategies. Molecular data were corroborated with several in situ techniques and usage of newly synthesized mouse monoclonal antibodies. fls485 mRNA expression was preferentially found in enterocytes and chromaffine cells of human intestinal mucosa as well as in several cell lines including Rko, Lovo, and CaCo2 cells. Western blot analysis with our new anti-fls485 antibodies revealed at least two fls485 proteins. In a functional CaCo2 model, an increase in fls485 expression was paralleled by cellular maturation stage. Immunohistochemistry demonstrated fls485 as a cytosolic protein with a slightly increasing expression gradient along the crypt-villus axis which was impaired in celiac disease Marsh IIIa-c. Expression and synthesis of fls485 are found in surface lining epithelia of normal human intestinal mucosa and deriving epithelial cell lines. An interdependence of enterocyte differentiation along the crypt-villus axis and fls485 chaperone activity might be possible.

  3. Type I collagen as an extracellular matrix for the in vitro growth of human small intestinal epithelium.

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    Ziyad Jabaji

    Full Text Available We previously reported in vitro maintenance and proliferation of human small intestinal epithelium using Matrigel, a proprietary basement membrane product. There are concerns over the applicability of Matrigel-based methods for future human therapies. We investigated type I collagen as an alternative for the culture of human intestinal epithelial cells.Human small intestine was procured from fresh surgical pathology specimens. Small intestinal crypts were isolated using EDTA chelation. Intestinal subepithelial myofibroblasts were isolated from a pediatric sample and expanded in vitro. After suspension in Matrigel or type I collagen gel, crypts were co-cultured above a confluent layer of myofibroblasts. Crypts were also grown in monoculture with exposure to myofibroblast conditioned media; these were subsequently sub-cultured in vitro and expanded with a 1∶2 split ratio. Cultures were assessed with light microscopy, RT-PCR, histology, and immunohistochemistry.Collagen supported viable human epithelium in vitro for at least one month in primary culture. Sub-cultured epithelium expanded through 12 passages over 60 days. Histologic sections revealed polarized columnar cells, with apical brush borders and basolaterally located nuclei. Collagen-based cultures gave rise to monolayer epithelial sheets at the gel-liquid interface, which were not observed with Matrigel. Immunohistochemical staining identified markers of differentiated intestinal epithelium and myofibroblasts. RT-PCR demonstrated expression of α-smooth muscle actin and vimentin in myofibroblasts and E-Cadherin, CDX2, villin 1, intestinal alkaline phosphatase, chromogranin A, lysozyme, and Lgr5 in epithelial cells. These markers were maintained through several passages.Type I collagen gel supports long-term in vitro maintenance and expansion of fully elaborated human intestinal epithelium. Collagen-based methods yield familiar enteroid structures as well as a new pattern of sheet

  4. Probiotics and commensals reverse TNF-alpha- and IFN-gamma-induced dysfunction in human intestinal epithelial cells.

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    Resta-Lenert, Silvia; Barrett, Kim E

    2006-03-01

    Commensal bacteria are crucial for the development of the mucosal immune system. Probiotics are commensals with special characteristics and may protect mucosal surfaces against pathogens. Pathogens cause significant phenotypic alterations in infected epithelial cells, and probiotics reverse these deleterious responses. We hypothesized that probiotics and/or commensals may also reverse epithelial damage produced by cytokines. Human intestinal epithelial cells were exposed basolaterally to interferon (IFN)-gamma (10(3) U/mL) or tumor necrosis factor (TNF)-alpha (10 ng/mL) for up to 48 hours and assessed for ion transport, transepithelial resistance (TER), and epithelial permeability in the presence or absence of probiotics (Streptococcus thermophilus [ST] and Lactobacillus acidophilus [LA]), or the commensal, Bacteroides thetaiotaomicron (BT). Agonist-stimulated chloride secretion was inhibited by IFN-gamma, an effect prevented by ST/LA or BT. The ability of ST/LA or BT to restore Cl(-) secretion was blocked by inhibitors of p38 MAPK, ERK1, 2, and PI3K. The cystic fibrosis transmembrane conductance regulator (CFTR) and the NKCC1 cotransporter were down-regulated by IFN-gamma, and ST/LA pretreatment reversed this effect. Both TNF-alpha and IFN-gamma significantly reduced TER and increased epithelial permeability, effects prevented by ST/LA or BT. A Janus kinase (JAK) inhibitor synergistically potentiated effects of ST/LA or BT on TER and permeability, but p38, ERK1, 2, or PI3K inhibition did not. Finally, only probiotic-treated epithelial cells exposed to cytokines showed reduced activation of SOCS3 and STAT1,3. Deleterious effects of TNF-alpha and IFN-gamma on epithelial function are prevented by probiotic, and to a lesser extent, commensal pretreatment. These data extend the spectrum of effects of such bacteria on intestinal epithelial function and may justify their use in inflammatory disorders.

  5. Effect of selenium nanoparticles with different sizes in primary cultured intestinal epithelial cells of crucian carp, Carassius auratus gibelio

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    Wang YB

    2013-10-01

    Full Text Available Yanbo Wang, Xuxia Yan, Linglin Fu Marine Resources and Nutrition Biology Research Center, Food Quality and Safety Department, Zhejiang Gongshang University, Hangzhou, People's Republic of China Abstract: Nano-selenium (Se, with its high bioavailability and low toxicity, has attracted wide attention for its potential application in the prevention of oxidative damage in animal tissues. However, the effect of nano-Se of different sizes on the intestinal epithelial cells of the crucian carp (Carassius auratus gibelio is poorly understood. Our study showed that different sizes and doses of nano-Se have varied effects on the cellular protein contents and the enzyme activities of secreted lactate dehydrogenase, intracellular sodium potassium adenosine triphosphatase, glutathione peroxidase, and superoxide dismutase. It was also indicated that nano-Se had a size-dependent effect on the primary intestinal epithelial cells of the crucian carp. Thus, these findings may bring us a step closer to understanding the size effect and the bioavailability of nano-Se on the intestinal tract of the crucian carp. Keywords: selenium nanoparticle, intestinal epithelial cell, crucian carp, primary culture

  6. Influência da suplementação de glutamina sobre o desempenho e o desenvolvimento de vilos e criptas do intestino delgado de frangos Influence of glutamine supplementation on performance and intestinal villous and crypt development in broiler chickens

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    A. Maiorka

    2000-10-01

    Full Text Available Investigou-se o efeito da suplementação de glutamina na dieta sobre o consumo de ração, ganho de peso e conversão alimentar e sobre a estrutura da mucosa intestinal de frangos. Foram utilizados 320 pintos de corte machos distribuídos em um delineamento inteiramente ao acaso com dois tratamentos e quatro repetições, sendo T1 suplementado com 1% de L-glutamina na dieta e T2 controle. Os índices de desempenho foram analisados aos 7, 21 e 49 dias de idade das aves. Aos 7 e 14 dias de idade oito aves foram sacrificadas para colheita de fragmentos de cada porção do intestino delgado para avaliação da morfometria intestinal em microscopia de luz em sistema analisador de imagens "Video Plan". As variáveis estudadas foram altura dos vilos, profundidade de cripta e relação vilo: cripta. A adição de 1% de glutamina à dieta de frangos não influenciou (P>0,05 o seu desempenho zootécnico. Entretanto, 1% de glutamina na ração foi capaz de alterar (PThis investigation was carried out in order to study the influence of glutamine supplementation in the ration on performance and on the intestinal structure development of broiler chickens. Three hundred and twenty day-old broiler chickens were used in a completely randomized experiment with two treatments and four repetitions, being T1 supplemented with 1% L-glutamine and T2 - control (not supplemented. The performance was evaluated (feed intake, body weight gain and feed conversion at 7, 21 and 49 days of age. At the same ages birds were sacrificed and samples from different parts of the intestine were collected (duodenum, jejunum and ileum to be submitted to morphometric studies under light microscopy using an image analysis system (Video Plan. The variables studied were villous height, crypt depth and villous:crypt ratio. It was demonstrated that 1% glutamine supplementation in the ration did not influence the broiler chicken performance (P>0.05 during the different phases of growth

  7. A new role for reticulon-4B/NOGO-B in the intestinal epithelial barrier function and inflammatory bowel disease.

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    Rodríguez-Feo, Juan Antonio; Puerto, Marta; Fernández-Mena, Carolina; Verdejo, Cristina; Lara, José Manuel; Díaz-Sánchez, María; Álvarez, Emilio; Vaquero, Javier; Marín-Jiménez, Ignacio; Bañares, Rafael; Menchén, Luis

    2015-06-15

    Inflammatory bowel disease (IBD) is characterized by an impaired intestinal barrier function. We aimed to investigate the role of reticulon-4B (RTN-4B/NOGO-B), a structural protein of the endoplasmic reticulum, in intestinal barrier function and IBD. We used immunohistochemistry, confocal microscopy, real-time PCR, and Western blotting to study tissue distribution and expression levels of RTN-4B/NOGO-B in control and IBD samples from mouse and humans. We also targeted RTN-4B/NOGO-B using siRNAs in cultured human intestinal epithelial cell (IECs). Epithelial barrier permeability was assessed by transepithelial electrical resistance (TEER) measurement. RTN-4B/NOGO-B is expressed in the intestine mainly by IECs. Confocal microscopy revealed a colocalization of RTN-4B, E-cadherin, and polymerized actin fibers in tissue and cultured IECs. RTN-4B mRNA and protein expression were lower in the colon of IL-10(-/-) compared with wild-type mice. Colocalization of RTN-4B/E-cadherin/actin was reduced in the colon of IL-10(-/-) mice. Analysis of endoscopic biopsies from IBD patients showed a significant reduction of RTN-4B/NOGO-B expression in inflamed mucosa compared with control. Treatment of IECs with H2O2 reduced TEER values and triggered phosphorylation of RTN-4B in serine 107 residues as well as downregulation of RTN-4B expression. Acute RTN-4B/NOGO-B knockdown by siRNAs resulted in a decreased TEER values and reduction of E-cadherin and α-catenin expression and in the amount of F-actin-rich filaments in IECs. Epithelial RTN-4B/NOGO-B was downregulated in human and experimental IBD. RTN-4B participates in the intestinal epithelial barrier function, most likely via its involvement in E-cadherin, α-catenin expression, and actin cytoskeleton organization at sites of cell-to-cell contacts.

  8. Transactivation of EGF receptor and ErbB2 protects intestinal epithelial cells from TNF-induced apoptosis.

    Science.gov (United States)

    Yamaoka, Toshimitsu; Yan, Fang; Cao, Hanwei; Hobbs, Stuart S; Dise, Rebecca S; Tong, Wei; Polk, D Brent

    2008-08-19

    TNF is a pleiotropic cytokine that activates both anti- and proapoptotic signaling pathways, with cell fate determined by the balance between these two pathways. Activation of ErbB family members, including EGF receptor (EGFR/ErbB1), promotes cell survival and regulates several signals that overlap with those stimulated by TNF. This study was undertaken to determine the effects of TNF on EGFR and ErbB2 activation and intestinal epithelial cell survival. Mice, young adult mouse colon epithelial cells, and EGFR knockout mouse colon epithelial cells were treated with TNF. Activation of EGFR, ErbB2, Akt, Src, and apoptosis were determined in vivo and in vitro. TNF stimulated EGFR phosphorylation in young adult mouse colon epithelial cells, and loss of EGFR expression or inhibition of kinase activity increased TNF-induced apoptosis, which was prevented in WT but not by kinase-inactive EGFR expression. Similarly, TNF injection stimulated apoptosis in EGFR-kinase-defective mice (EGFR(wa2)) compared with WT mice. TNF also activated ErbB2, and loss of ErbB2 expression increased TNF-induced apoptosis. Furthermore, Src-kinase activity and the expression of both EGFR and ErbB2 were required for TNF-induced cell survival. Akt was shown to be a downstream target of TNF-activated EGFR and ErbB2. These findings demonstrate that EGFR and ErbB2 are critical mediators of TNF-regulated antiapoptotic signals in intestinal epithelial cells. Given evidence for TNF signaling in the development of colitis-associated carcinoma, this observation has significant implications for understanding the role of EGFR in maintaining intestinal epithelial cell homeostasis during cytokine-mediated inflammatory responses.

  9. Effects of the Probiotic Enterococcus faecium and Pathogenic Escherichia coli Strains in a Pig and Human Epithelial Intestinal Cell Model

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    Ulrike Lodemann

    2015-01-01

    Full Text Available The aim of this study has been to elucidate the effect of the probiotic Enterococcus faecium NCIMB 10415 on epithelial integrity in intestinal epithelial cells and whether pre- and coincubation with this strain can reproducibly prevent damage induced by enterotoxigenic (ETEC and enteropathogenic Escherichia coli (EPEC. Porcine (IPEC-J2 and human (Caco-2 intestinal epithelial cells were incubated with bacterial strains and epithelial integrity was assessed by measuring transepithelial electrical resistance (TEER and mannitol flux rates. E. faecium alone increased TEER of Caco-2 cells without affecting mannitol fluxes whereas the E. coli strains decreased TEER and concomitantly increased mannitol flux rates in both cell lines. Preincubation with E. faecium had no effect on the TEER decrease induced by E. coli in preliminary experiments. However, in a second set of experiments using a slightly different protocol, E. faecium ameliorated the TEER decrease induced by ETEC at 4 h in IPEC-J2 and at 2, 4, and 6 h in Caco-2 cells. We conclude that E. faecium positively affected epithelial integrity in monoinfected Caco-2 cells and could ameliorate the damage on TEER induced by an ETEC strain. Reproducibility of the results is, however, limited when experiments are performed with living bacteria over longer periods.

  10. Platelet-activating factor induces TLR4 expression in intestinal epithelial cells: implication for the pathogenesis of necrotizing enterocolitis.

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    Antoine Soliman

    Full Text Available Necrotizing enterocolitis (NEC is a leading cause of morbidity and mortality in neonatal intensive care units, however its pathogenesis is not completely understood. We have previously shown that platelet activating factor (PAF, bacteria and TLR4 are all important factors in the development of NEC. Given that Toll-like receptors (TLRs are expressed at low levels in enterocytes of the mature gastrointestinal tract, but were shown to be aberrantly over-expressed in enterocytes in experimental NEC, we examined the regulation of TLR4 expression and signaling by PAF in intestinal epithelial cells using human and mouse in vitro cell lines, and the ex vivo rat intestinal loop model. In intestinal epithelial cell (IEC lines, PAF stimulation yielded upregulation of both TLR4 mRNA and protein expression and led to increased IL-8 secretion following stimulation with LPS (in an otherwise LPS minimally responsive cell line. PAF stimulation resulted in increased human TLR4 promoter activation in a dose dependent manner. Western blotting and immunohistochemical analysis showed PAF induced STAT3 phosphorylation and nuclear translocation in IEC, and PAF-induced TLR4 expression was inhibited by STAT3 and NFκB Inhibitors. Our findings provide evidence for a mechanism by which PAF augments inflammation in the intestinal epithelium through abnormal TLR4 upregulation, thereby contributing to the intestinal injury of NEC.

  11. The development of the chicken small intestine: a scanning electron microscopy study.

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    Sabatakou, O; Paraskevakou, E; Tseleni-Balafouta, S; Athanasiadis, A; Fasseas, K

    2003-07-01

    The surface pattern of the small intestine of the chicken was studied using SEM in stages ranging from 11th day of foetal development to 60 days of post-natal life. The definite villi of the small intestine were preceded by the development of the previllous ridges. The villi were finger like and of unequal length during incubation. After hatching, gradually, the villi were longer, well formed with furrows along their sides. Respectively, the crypts, being present at late incubation, increased with age. Columnar epithelial cells with dense microvilli lined the luminal surface of the intestine with obvious goblet cells openings among them.

  12. Effects of the ionising radiations on the structure and the function of the intestinal epithelial cell; Effets des rayonnements ionisants sur la structure et la fonction de la cellule epitheliale intestinale

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    Haton, C

    2005-06-15

    The intestinal mucosa is a particularly radio-sensitive tissue and damage may occur following either accidental or therapeutic exposure. the deleterious actions of ionizing radiation are linked to the formation of sometimes overwhelming quantities of reactive oxygen species (R.O.S.). Production of R.O.S. is both direct and indirect from the secondary effects of irradiation. A better comprehension of the underlying mechanisms of injury will lead to more adapted therapeutic approaches to limit the harmful effects of irradiation. The homeostasis of the intestinal epithelium is regulated by three factors: proliferation, apoptosis and differentiation. these three factors were studied using the cell model, HT29, in order to analyze modulations of this balance after irradiation. our results, in agreement with other data, showed the establishment of mitotic delay. This arrest of proliferation was followed by apoptosis to be the major mechanism leading to cell death in this model. thus, for the first time, we have shown that irradiated intestinal epithelial cells preserve their capacity to differentiate. This indicates, although indirectly, that intestinal cells have and preserve an intrinsic capacity restore a functional epithelium. R.O.S. are considered as intermediates between the physical nature of radiations and biological responses. It seems essential to understand anti-oxidant mechanisms used by the cell for defence against the deleterious effects of R.O.S post exposure. This study of several anti-oxidant defence mechanisms of intestinal mucosa, was carried out in vivo in the mouse at different times following abdominal irradiation. We observed an early mitochondrial response in the hours following irradiation revealing this organelle as a particular target. We demonstrated a strong alteration of anti-oxidant capacity as revealed by a decrease in S.O.D.s, catalase and an increase of the G.P.X.s and M.T.s. A part of these modifications appeared to depend on an

  13. Air–liquid interface enhances oxidative phosphorylation in intestinal epithelial cell line IPEC-J2

    Science.gov (United States)

    Klasvogt, Sonja; Zuschratter, Werner; Schmidt, Anke; Kröber, Andrea; Vorwerk, Sandra; Wolter, Romina; Isermann, Berend; Wimmers, Klaus; Rothkötter, Hermann-Josef; Nossol, Constanze

    2017-01-01

    The intestinal porcine epithelial cell line IPEC-J2, cultured under the air–liquid interface (ALI) conditions, develops remarkable morphological characteristics close to intestinal epithelial cells in vivo. Improved oxygen availability has been hypothesised to be the leading cause of this morphological differentiation. We assessed oxygen availability in ALI cultures and examined the influence of this cell culture method on glycolysis and oxidative phosphorylation in IPEC-J2 using the submerged membrane culture (SMC) and ALI cultures. Furthermore, the role of HIF-1 as mediator of oxygen availability was analysed. Measurements of oxygen tension confirmed increased oxygen availability at the medium–cell interface and demonstrated reduced oxygen extraction at the basal compartment in ALI. Microarray analysis to determine changes in the genetic profile of IPEC-J2 in ALI identified 2751 modified transcripts. Further examinations of candidate genes revealed reduced levels of glycolytic enzymes hexokinase II and GAPDH, as well as lactate transporting monocarboxylate transporter 1 in ALI, whereas expression of the glucose transporter GLUT1 remained unchanged. Cytochrome c oxidase (COX) subunit 5B protein analysis was increased in ALI, although mRNA level remained at constant level. COX activity was assessed using photometric quantification and a three-fold increase was found in ALI. Quantification of glucose and lactate concentrations in cell culture medium revealed significantly reduced glucose levels and decreased lactate production in ALI. In order to evaluate energy metabolism, we measured cellular adenosine triphosphate (ATP) aggregation in homogenised cell suspensions showing similar levels. However, application of the uncoupling agent FCCP reduced ATP levels in ALI but not in SMC. In addition, HIF showed reduced mRNA levels in ALI. Furthermore, HIF-1α protein was reduced in the nuclear compartment of ALI when compared to SCM as confirmed by confocal microscopy

  14. Damaged intestinal epithelial integrity linked to microbial translocation in pathogenic simian immunodeficiency virus infections.

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    Jacob D Estes

    Full Text Available The chronic phase of HIV infection is marked by pathological activation of the immune system, the extent of which better predicts disease progression than either plasma viral load or CD4(+ T cell count. Recently, translocation of microbial products from the gastrointestinal tract has been proposed as an underlying cause of this immune activation, based on indirect evidence including the detection of microbial products and specific immune responses in the plasma of chronically HIV-infected humans or SIV-infected Asian macaques. We analyzed tissues from SIV-infected rhesus macaques (RMs to provide direct in situ evidence for translocation of microbial constituents from the lumen of the intestine into the lamina propria and to draining and peripheral lymph nodes and liver, accompanied by local immune responses in affected tissues. In chronically SIV-infected RMs this translocation is associated with breakdown of the integrity of the epithelial barrier of the gastrointestinal (GI tract and apparent inability of lamina propria macrophages to effectively phagocytose translocated microbial constituents. By contrast, in the chronic phase of SIV infection in sooty mangabeys, we found no evidence of epithelial barrier breakdown, no increased microbial translocation and no pathological immune activation. Because immune activation is characteristic of the chronic phase of progressive HIV/SIV infections, these findings suggest that increased microbial translocation from the GI tract, in excess of capacity to clear the translocated microbial constituents, helps drive pathological immune activation. Novel therapeutic approaches to inhibit microbial translocation and/or attenuate chronic immune activation in HIV-infected individuals may complement treatments aimed at direct suppression of viral replication.

  15. Cdc42 and Rab8a are critical for intestinal stem cell division, survival, and differentiation in mice

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    Sakamori, Ryotaro; Das, Soumyashree; Yu, Shiyan

    2012-01-01

    The constant self renewal and differentiation of adult intestinal stem cells maintains a functional intestinal mucosa for a lifetime. However, the molecular mechanisms that regulate intestinal stem cell division and epithelial homeostasis are largely undefined. We report here that the small GTPases...... reminiscent of human microvillus inclusion disease (MVID), a devastating congenital intestinal disorder that results in severe nutrient deprivation. Further analysis revealed that Cdc42-deficient stem cells had cell division defects, reduced capacity for clonal expansion and differentiation into Paneth cells...... activity in the intestinal epithelium, where continued cell division takes place. Furthermore, mice haploinsufficient for both Cdc42 and Rab8a in the intestine demonstrated abnormal crypt morphogenesis and epithelial transporter physiology, further supporting their functional interaction. These data...

  16. Energetics of coupled Na+ and Cl- entry into epithelial cells of bullfrog small intestine.

    Science.gov (United States)

    Armstrong, W M; Bixenman, W R; Frey, K F; Garcia-Diaz, J F; O'Regan, M G; Owens, J L

    1979-02-20

    Na+, K+ and Cl- concentrations (cij) and activities (aij), and mucosal membrane potentials (Em) were measured in epithelial cells of isolated bullfrog (Rana catesbeiana) small intestine. Segments of intestine were stripped of their external muscle layers, and bathed (at 25 degrees C and pH 7.2) in oxygenated Ringer solutions containing 105 mM Na+ and Cl- and 5.4 mM K+. Na+ and K+ concentrations were determined by atomic absorption spectrometry and Cl- concentrations by conductometric titration following extraction of the dried tissue with 0.1 M HNO3. 14C-labelled inulin was used to determine extracellular volume. Em was measured with conventional open tip microelectrodes, aiCl with solid-state Cl-selective silver microelectrodes and aiNa and aiK with Na+ and K+-selective liquid ion-exchanger microelectrodes. The average Em recorded was -34mV. ciNa, ciK and ciCl were 51, 105 and 52 mM. The corresponding values for aiNa, aiK and aiCl were 18, 80 and 33 mM. These results suggest that a large fraction of the cytoplasmic Na+ is 'bound' or sequestered in an osmotically inactive form, that all, or virtually all the cytoplasmic K+ behaves as if in free solution, and that there is probably some binding of cytoplasmic Cl-. aiCl significantly exceeds the level corresponding to electrochemical equilibrium across the mucosal and baso-lateral cell membranes. Earlier studies showed that coupled mucosal entry of Na+ and Cl- is implicated in intracellular Cl- accumulation in this tissue. This study permitted estimation of the steady-state transapical Na+ and Cl- electrochemical potential differences (deltamuNa and deltamuCl). deltamuNa (-7000 J . mol-1; cell minus mucosal medium) was energetically more than sufficient to account for deltamuCl (1000--2000 J . mol-1).

  17. Lactobacillus acidophilus alleviates platelet-activating factor-induced inflammatory responses in human intestinal epithelial cells.

    Directory of Open Access Journals (Sweden)

    Alip Borthakur

    Full Text Available Probiotics have been used as alternative prevention and therapy modalities in intestinal inflammatory disorders including inflammatory bowel diseases (IBD and necrotizing enterocolitis (NEC. Pathophysiology of IBD and NEC includes the production of diverse lipid mediators, including platelet-activating factor (PAF that mediate inflammatory responses in the disease. PAF is known to activate NF-κB, however, the mechanisms of PAF-induced inflammation are not fully defined. We have recently described a novel PAF-triggered pathway of NF-κB activation and IL-8 production in intestinal epithelial cells (IECs, requiring the pivotal role of the adaptor protein Bcl10 and its interactions with CARMA3 and MALT1. The current studies examined the potential role of the probiotic Lactobacillus acidophilus in reversing the PAF-induced, Bcl10-dependent NF-κB activation and IL-8 production in IECs. PAF treatment (5 µM×24 h of NCM460 and Caco-2 cells significantly increased nuclear p65 NF-κB levels and IL-8 secretion (2-3-fold, P<0.05, compared to control, which were blocked by pretreatment of the cells for 6 h with L. acidophilus (LA or its culture supernatant (CS, followed by continued treatments with PAF for 24 h. LA-CS also attenuated PAF-induced increase in Bcl10 mRNA and protein levels and Bcl10 promoter activity. LA-CS did not alter PAF-induced interaction of Bcl10 with CARMA3, but attenuated Bcl10 interaction with MALT1 and also PAF-induced ubiquitination of IKKγ. Efficacy of bacteria-free CS of LA in counteracting PAF-induced inflammatory cascade suggests that soluble factor(s in the CS of LA mediate these effects. These results define a novel mechanism by which probiotics counteract PAF-induced inflammation in IECs.

  18. The Nucleotide Synthesis Enzyme CAD Inhibits NOD2 Antibacterial Function in Human Intestinal Epithelial Cells

    Science.gov (United States)

    Richmond, Amy L.; Kabi, Amrita; Homer, Craig R.; García, Noemí Marina; Nickerson, Kourtney P.; NesvizhskiI, Alexey I.; Sreekumar, Arun; Chinnaiyan, Arul M.; Nuñez, Gabriel; McDonald, Christine

    2013-01-01

    BACKGROUND & AIMS Polymorphisms that reduce the function of nucleotide-binding oligomerization domain (NOD)2, a bacterial sensor, have been associated with Crohn’s disease (CD). No proteins that regulate NOD2 activity have been identified as selective pharmacologic targets. We sought to discover regulators of NOD2 that might be pharmacologic targets for CD therapies. METHODS Carbamoyl phosphate synthetase/ aspartate transcarbamylase/dihydroorotase (CAD) is an enzyme required for de novo pyrimidine nucleotide synthesis; it was identified as a NOD2-interacting protein by immunoprecipitation-coupled mass spectrometry. CAD expression was assessed in colon tissues from individuals with and without inflammatory bowel disease by immunohistochemistry. The interaction between CAD and NOD2 was assessed in human HCT116 intestinal epithelial cells by immunoprecipitation, immunoblot, reporter gene, and gentamicin protection assays. We also analyzed human cell lines that express variants of NOD2 and the effects of RNA interference, overexpression and CAD inhibitors. RESULTS CAD was identified as a NOD2-interacting protein expressed at increased levels in the intestinal epithelium of patients with CD compared with controls. Overexpression of CAD inhibited NOD2-dependent activation of nuclear factor κB and p38 mitogen-activated protein kinase, as well as intracellular killing of Salmonella. Reduction of CAD expression or administration of CAD inhibitors increased NOD2-dependent signaling and antibacterial functions of NOD2 variants that are and are not associated with CD. CONCLUSIONS The nucleotide synthesis enzyme CAD is a negative regulator of NOD2. The antibacterial function of NOD2 variants that have been associated with CD increased in response to pharmacologic inhibition of CAD. CAD is a potential therapeutic target for CD. PMID:22387394

  19. Autocrine DNA fragmentation of intra-epithelial lymphocytes (IELs) in mouse small intestine.

    Science.gov (United States)

    Ogata, Masaki; Ota, Yuta; Nanno, Masanobu; Suzuki, Ryuji; Itoh, Tsunetoshi

    2015-09-01

    Intraepithelial lymphocytes (IELs) are present in the intestinal epithelium. Mechanisms of IELs for the protection of villi from foreign antigens and from infections by micro-organisms have not been sufficiently explained. Although more than 70% of mouse duodenal and jejunal IELs bear γδTCR (γδIELs), the functions of γδIELs are little investigated. We stimulate γδIELs by anti-CD3 monoclonal antibody (mAb) injection. The mAb activates γδIELs to release Granzyme B (GrB) into the spaces surrounding the γδIELs and intestinal villous epithelial cells (IECs). Released GrB induces DNA fragmentation in IECs independently of Perforin (Pfn). IECs immediately repair their fragmented DNA. Activated IELs reduce their cell size, remain for some time in the epithelium after the activation and are ultimately eliminated without leaving the site. We focus our attention on the response of IELs to the released GrB present in the gap surrounding IELs, after activation, in order to examine whether the released GrB has a similar effect on IELs to that observed on IECs in our previous studies. DNA fragmentation is also induced in IELs together with the repair of fragmented DNA thereafter. The time-kinetics of both events were found to be identical to those observed in IECs. DNA fragmentation in IELs is Pfn-independent. Here, we present Pfn-independent "autocrine DNA fragmentation" in IELs and the repair of fragmented DNA in IELs and discuss their biological significance. Autocrine DNA fragmentation has never been reported to date in vivo.

  20. Fatty Acid Ethyl Esters Induce Intestinal Epithelial Barrier Dysfunction via a Reactive Oxygen Species-Dependent Mechanism in a Three-Dimensional Cell Culture Model

    NARCIS (Netherlands)

    Elamin, Elhaseen; Masclee, Ad; Juuti-Uusitalo, Kati; van IJzendoorn, Sven; Troost, Freddy; Pieters, Harm-Jan; Dekker, Jan; Jonkers, Daisy

    2013-01-01

    Background & Aims: Evidence is accumulating that ethanol and its oxidative metabolite, acetaldehyde, can disrupt intestinal epithelial integrity, an important factor contributing to ethanol-induced liver injury. However, ethanol can also be metabolized non-oxidatively generating phosphatidylethanol

  1. Fatty Acid Ethyl Esters Induce Intestinal Epithelial Barrier Dysfunction via a Reactive Oxygen Species-Dependent Mechanism in a Three-Dimensional Cell Culture Model

    NARCIS (Netherlands)

    Elamin, E.; Masclee, A.A.M.; Juuti-Uusitalo, K.; IJzendoorn, van S.; Troost, F.; Pieters, H.J.; Dekker, J.; Jonkers, D.

    2013-01-01

    Background & Aims: Evidence is accumulating that ethanol and its oxidative metabolite, acetaldehyde, can disrupt intestinal epithelial integrity, an important factor contributing to ethanol-induced liver injury. However, ethanol can also be metabolized non-oxidatively generating phosphatidyletha

  2. Analysis of the human intestinal epithelial cell transcriptional response to Lactobacillus acidophilus, Lactobacillus salivarius, Bifidobacterium lactis and Escherichia coli

    DEFF Research Database (Denmark)

    Putaala, H; Barrangou, R; Leyer, G J

    2010-01-01

    The complex microbial population residing in the human gastrointestinal tract consists of commensal, potential pathogenic and beneficial species, which are probably perceived differently by the host and consequently could be expected to trigger specific transcriptional responses. Here, we provide...... insights into the relationship between probiotics and human intestinal epithelial cells, notably with regard to strain-specific responses, and highlight the differences between transcriptional responses to pathogenic and probiotic bacteria.......The complex microbial population residing in the human gastrointestinal tract consists of commensal, potential pathogenic and beneficial species, which are probably perceived differently by the host and consequently could be expected to trigger specific transcriptional responses. Here, we provide...... a comparative analysis of the global in vitro transcriptional response of human intestinal epithelial cells to Lactobacillus acidophilus NCFM™, Lactobacillus salivarius Ls-33, Bifidobacterium animalis subsp. lactis 420, and enterohaemorrhagic Escherichia coli O157:H7 (EHEC). Interestingly, L. salivarius Ls-33...

  3. Strategies of the protozoan parasite Entamoeba histolytica to evade the innate immune responses of intestinal epithelial cells

    Indian Academy of Sciences (India)

    S Ankri

    2002-11-01

    Molecules expressed by the pathogenic ameoba Entamoeba histolytica but weakly expressed or absent from the non-pathogenic ameoba Entamoeba dispar could be used by intestinal epithelial cells to discriminate between the two species and to initiate an appropriate inflammatory response. Among the possible molecules involved in this identification are the Gal/GalNac lectin and the lipophosphoglycan. Once the inflammatory response is initiated, E. histolytica trophozoites have to protect themselves against reactive nitrogen intermediates produced by intestinal epithelial cells, oxygen intermediates, and cytotoxic molecules released by activated neutrophils. By screening the E. histolytica genome, we have identified proteins that may play a role in the defence strategy of the parasite. One of these proteins, a serine proteinase inhibitor, inhibits human neutrophil cathepsin G, a key component of the host defence.

  4. A commensal Helicobacter sp. of the rodent intestinal flora activates TLR2 and NOD1 responses in epithelial cells.

    Science.gov (United States)

    Chaouche-Drider, Nadia; Kaparakis, Maria; Karrar, Abdulgader; Fernandez, Maria-Isabel; Carneiro, Letitia A M; Viala, Jérôme; Boneca, Ivo Gomperts; Moran, Anthony P; Philpott, Dana J; Ferrero, Richard L

    2009-01-01

    Helicobacter spp. represent a proportionately small but significant component of the normal intestinal microflora of animal hosts. Several of these intestinal Helicobacter spp. are known to induce colitis in mouse models, yet the mechanisms by which these bacteria induce intestinal inflammation are poorly understood. To address this question, we performed in vitro co-culture experiments with mouse and human epithelial cell lines stimulated with a selection of Helicobacter spp., including known pathogenic species as well as ones for which the pathogenic potential is less clear. Strikingly, a member of the normal microflora of rodents, Helicobacter muridarum, was found to be a particularly strong inducer of CXC chemokine (Cxcl1/KC, Cxcl2/MIP-2) responses in a murine intestinal epithelial cell line. Time-course studies revealed a biphasic pattern of chemokine responses in these cells, with H. muridarum lipopolysaccharide (LPS) mediating early (24-48 h) responses and live bacteria seeming to provoke later (48-72 h) responses. H. muridarum LPS per se was shown to induce CXC chemokine production in HEK293 cells stably expressing Toll-like receptor 2 (TLR2), but not in those expressing TLR4. In contrast, live H. muridarum bacteria were able to induce NF-kappaB reporter activity and CXC chemokine responses in TLR2-deficient HEK293 and in AGS epithelial cells. These responses were attenuated by transient transfection with a dominant negative construct to NOD1, and by stable expression of NOD1 siRNA, respectively. Thus, the data suggest that both TLR2 and NOD1 may be involved in innate immune sensing of H. muridarum by epithelial cells. This work identifies H. muridarum as a commensal bacterium with pathogenic potential and underscores the potential roles of ill-defined members of the normal flora in the initiation of inflammation in animal hosts. We suggest that H. muridarum may act as a confounding factor in colitis model studies in rodents.

  5. Pregnane-X-receptor mediates the anti-inflammatory activities of rifaximin on detoxification pathways in intestinal epithelial cells.

    Science.gov (United States)

    Mencarelli, Andrea; Migliorati, Marco; Barbanti, Miriam; Cipriani, Sabrina; Palladino, Giuseppe; Distrutti, Eleonora; Renga, Barbara; Fiorucci, Stefano

    2010-12-01

    The pregnane-X-receptor (PXR) is master gene overseeing detoxification of wide number of xenobiotics and is critical for maintenance of intestinal integrity. The intestinal expression of genes involved in cellular detoxification is down-regulated in patients with inflammatory bowel diseases (IBD). Rifaximin is a non-absorbable antibiotic endowed with a PXR agonistic activity. In the present study we have investigated whether rifaximin activates PXR in primary human colon epithelial cells and human colon biopsies and assessed whether this antibiotic antagonizes the effect of tumor necrosis factor (TNF)-α on expression of PXR and PXR-related genes. Present results demonstrate that primary colon epithelial cells express PXR and that their exposure to rifaximin induces the expression of genes involved in cellular detoxification. Exposure to TNFα reduces the expression of PXR mRNA as well as expression of its target genes. This inhibitory effect was prevented by that co-treatment with rifaximin. Knocking down the expression of PXR in colon epithelial cells by an anti-PXR siRNA, abrogated the counter-regulatory effects exerted by rifaximin on cell exposed to TNFα. Finally, ex vivo exposure of colon biopsies obtained from ulcerative colitis patients to rifaximin increased the expression of genes involved in xenobiotics metabolism. In aggregate, these data illustrate that rifaximin increases the expression of PXR and PXR-regulated genes involved in the metabolism and excretion of xenobiotics and antagonizes the effects of TNFα in intestinal epithelial cells and colon biopsies. These non-antibiotic effects of rifaximin could contribute to the maintenance of the intestinal barrier integrity against xenobiotics and products generated by luminal bacteria.

  6. Inhibition of the NF-kappaB pathway in human intestinal epithelial cells by commensal Streptococcus salivarius.

    Science.gov (United States)

    Kaci, Ghalia; Lakhdari, Omar; Doré, Joël; Ehrlich, S Dusko; Renault, Pierre; Blottière, Hervé M; Delorme, Christine

    2011-07-01

    Streptococcus salivarius exhibited an anti-inflammatory effect on intestinal epithelial cells (IECs) and monocytes. Strains were screened using a reporter clone, HT-29/kB-luc-E, induced by tumor necrosis factor alpha (TNF-α). Supernatant from each strain downregulated NF-κB activation. The two most efficient strains produced an active metabolite (<3 kDa) which was able to downregulate the secretion of the proinflammatory chemokine interleukin-8 (IL-8).

  7. Inhibition of the NF-κB Pathway in Human Intestinal Epithelial Cells by Commensal Streptococcus salivarius ▿ †

    Science.gov (United States)

    Kaci, Ghalia; Lakhdari, Omar; Doré, Joël; Ehrlich, S. Dusko; Renault, Pierre; Blottière, Hervé M.; Delorme, Christine

    2011-01-01

    Streptococcus salivarius exhibited an anti-inflammatory effect on intestinal epithelial cells (IECs) and monocytes. Strains were screened using a reporter clone, HT-29/kB-luc-E, induced by tumor necrosis factor alpha (TNF-α). Supernatant from each strain downregulated NF-κB activation. The two most efficient strains produced an active metabolite (<3 kDa) which was able to downregulate the secretion of the proinflammatory chemokine interleukin-8 (IL-8). PMID:21602373

  8. Advanced application of bovine intestinal epithelial cell line for evaluating regulatory effect of lactobacilli against heat-killed enterotoxigenicEscherichia coli-mediated inflammation

    OpenAIRE

    Takanashi, Naoya; Tomosada, Yohsuke; Villena, Julio Cesar; Murata, Kozue; Takahashi, Takuya; Chiba, Eriko; Tohno, Masanori; Tomoyuki Shimazu; Aso, Hisashi; Suda, Yoshihito; Ikegami, Shuji; Itoh, Hiroyuki; Kawai, Yasushi; Tadao Saito; Alvarez, Gladis Susana

    2015-01-01

    Background: Previously, a bovine intestinal epithelial cell line (BIE cells) was successfully established. This work hypothesized that BIE cells are useful in vitro model system for the study of interactions of microbial- or pathogenassociated molecular patterns (MAMPs or PAMPs) with bovine intestinal epithelial cells and for the selection of immunoregulatory lactic acid bacteria (LAB). Results: All toll-like receptor (TLR) genes were expressed in BIE cells, being TLR4 one of the most strong...

  9. Short-Chain Fatty Acids Regulate Secretion of IL-8 from Human Intestinal Epithelial Cell Lines in vitro.

    Science.gov (United States)

    Asarat, M; Vasiljevic, T; Apostolopoulos, V; Donkor, O

    2015-01-01

    Short-chain fatty acids (SCFAs) including acetate, propionate and butyrate play an important role in the physiological functions of epithelial cells and colonocytes, such as immune response regulation. Human intestinal epithelial cells (IECs) contribute in intestinal immune response via different ways, such as production of different immune factors including Interleukin (IL) IL-8, which act as chemoattractant for neutrophils, and subsequently enhance inflammation. Therefore, we aimed to evaluate the effects of SCFAs on IECs viability and production of IL-8 in vitro. SCFAs were co-cultured with either normal intestinal epithelial (T4056) or adenocarcinoma derived (HT-29) cell lines for 24-96 h in the presence of E.coli lipopolysaccharides (LPS). Cell viability, proliferation, production of IL-8 and expression of IL-8 mRNA were determined in the cell cultures. The result showed that 20 mM of SCFAs was non-cytotoxic to T4056 and enhanced their growth, whereas the growth of HT-29 was inhibited. The SCFAs down regulated LPS-stimulated IL-8 secretion with different response patterns, but no obvious effects on the release of IL-8 from non LPS- stimulated cells. In conclusion, SCFAs showed regulatory effect on release of LPS-stimulated IL-8 as well as the expression of mRNA of IL-8; these might explain the anti-inflammatory and anti-carcinogenic mechanism of SCFAs.

  10. Regulation of Intestinal Epithelial Calcium Transport Proteins by Stanniocalcin-1 in Caco2 Cells

    Directory of Open Access Journals (Sweden)

    Jinmei Xiang

    2016-07-01

    Full Text Available Stanniocalcin-1 (STC1 is a calcium and phosphate regulatory hormone. However, the exact molecular mechanisms underlying how STC1 affects Ca2+ uptake remain unclear. Here, the expression levels of the calcium transport proteins involved in transcellular transport in Caco2 cells were examined following over-expression or inhibition of STC1. These proteins include the transient receptor potential vanilloid members (TRPV 5 and 6, the plasma membrane calcium ATPase 1b (PMCA1b, the sodium/calcium exchanger (NCX1, and the vitamin D receptor (VDR. Both gene and protein expressions of TRPV5 and TRPV6 were attenuated in response to over-expression of STC1, and the opposite trend was observed in cells treated with siRNASTC1. To further investigate the ability of STC1 to influence TRPV6 expression, cells were treated with 100 ng/mL of recombinant human STC1 (rhSTC1 for 4 h following pre-transfection with siRNASTC1 for 48 h. Intriguingly, the increase in the expression of TRPV6 resulting from siRNASTC1 was reversed by rhSTC1. No significant effect of STC1 on the expression of PMCA1b, NCX1 or VDR was observed in this study. In conclusion, the effect of STC1 on calcium transport in intestinal epithelia is due to, at least in part, its negative regulation of the epithelial channels TRPV5/6 that mediate calcium influx.

  11. Homoharringtonine increases intestinal epithelial permeability by modulating specific claudin isoforms in Caco-2 cell monolayers.

    Science.gov (United States)

    Watari, Akihiro; Hashegawa, Maki; Yagi, Kiyohito; Kondoh, Masuo

    2015-01-01

    Homoharringtonine (HHT), a natural alkaloid produced by various Cephalotaxus species, has antileukemic activity in acute and chronic myelogenous leukemia. However, HHT can also induce unanticipated effects in the gastrointestinal tract, such as diarrhea and nausea/vomiting, but the mechanism behind these adverse effects has not been clarified. In the present study, we show that HHT affects the epithelial permeability of intestinal Caco-2 cell monolayers. HHT reduced the transepithelial electrical resistance (TER) of Caco-2 cells in a dose- and time-dependent manner. The HHT effect was reversible and no cytotoxicity was observed at the concentrations used. HHT simultaneously increased the paracellular flux of the 4 kDa and 40 kDa FITC-dextrans associated with the TER reduction. Immunoblotting analysis revealed that HHT decreased the protein expression of TJ components such as claudin-3, -5, and -7. However, the transcription levels of these claudins were not repressed by HHT treatment. HHT also disturbed the cellular localization of claudin-1 and -4. These changes coincided with the reduced barrier function. Our findings suggest that HHT enhances the paracellular permeability of Caco-2 cell monolayers by modulating the protein expression and localization of claudin isoforms; these actions might be responsible for the gastrointestinal effects of HHT. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Salmonella Typhimurium Enzymatically Landscapes the Host Intestinal Epithelial Cell (IEC) Surface Glycome to Increase Invasion.

    Science.gov (United States)

    Park, Dayoung; Arabyan, Narine; Williams, Cynthia C; Song, Ting; Mitra, Anupam; Weimer, Bart C; Maverakis, Emanual; Lebrilla, Carlito B

    2016-12-01

    Although gut host-pathogen interactions are glycan-mediated processes, few details are known about the participating structures. Here we employ high-resolution mass spectrometric profiling to comprehensively identify and quantitatively measure the exact modifications of native intestinal epithelial cell surface N-glycans induced by S. typhimurium infection. Sixty minutes postinfection, select sialylated structures showed decreases in terms of total number and abundances. To assess the effect of cell surface mannosylation, we selectively rerouted glycan expression on the host using the alpha-mannosidase inhibitor, kifunensine, toward overexpression of high mannose. Under these conditions, internalization of S. typhimurium significantly increased, demonstrating that bacteria show preference for particular structures. Finally, we developed a novel assay to measure membrane glycoprotein turnover rates, which revealed that glycan modifications occur by bacterial enzyme activity rather than by host-derived restructuring strategies. This study is the first to provide precise structural information on how host N-glycans are altered to support S. typhimurium invasion. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  13. Nivalenol induces oxidative stress and increases deoxynivalenol pro-oxidant effect in intestinal epithelial cells.

    Science.gov (United States)

    Del Regno, Marisanta; Adesso, Simona; Popolo, Ada; Quaroni, Andrea; Autore, Giuseppina; Severino, Lorella; Marzocco, Stefania

    2015-06-01

    Mycotoxins are secondary fungal metabolites often found as contaminants in almost all agricultural commodities worldwide, and the consumption of food or feed contaminated by mycotoxins represents a major risk for human and animal health. Reactive oxygen species are normal products of cellular metabolism. However, disproportionate generation of reactive oxygen species poses a serious problem to bodily homeostasis and causes oxidative tissue damage. In this study we analyzed the effect of two trichothecenes mycotoxins: nivalenol and deoxynivalenol, alone and in combination, on oxidative stress in the non-tumorigenic intestinal epithelial cell line IEC-6. Our results indicate the pro-oxidant nivalenol effect in IEC-6, the stronger pro-oxidant effect of nivalenol when compared to deoxynivalenol and, interestingly, that nivalenol increases deoxynivalenol pro-oxidative effects. Mechanistic studies indicate that the observed effects were mediated by NADPH oxidase, calcium homeostasis alteration, NF-kB and Nrf2 pathways activation and by iNOS and nitrotyrosine formation. The toxicological interaction by nivalenol and deoxynivalenol reported in this study in IEC-6, points out the importance of the toxic effect of these mycotoxins, mostly in combination, further highlighting the risk assessment process of these toxins that are of growing concern. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. BCFA suppresses LPS induced IL-8 mRNA expression in human intestinal epithelial cells.

    Science.gov (United States)

    Yan, Y; Wang, Z; Greenwald, J; Kothapalli, K S D; Park, H G; Liu, R; Mendralla, E; Lawrence, P; Wang, X; Brenna, J T

    2017-01-01

    Branched chain fatty acids (BCFA) are components of common food fats and are major constituents of the normal term human newborn GI tract. Polyunsaturated fatty acids (PUFA) have been suggested to reduce the risk and development of inflammatory bowel diseases (IBD); however, little is known about the influence of BCFA on inflammation. We investigated the effect of BCFA on interleukin (IL)-8 and NF-κB production in a human intestinal epithelial cell line (Caco-2). Cells were pre-treated with specific BCFA, or DHA, or EPA, and then activated with lipopolysaccharide (LPS). Both anteiso- and iso- BCFA reduce IL-8. Anteiso-BCFA more effectively suppressed IL-8 than iso-BCFA in LPS stimulated Caco-2 cells. However BCFA in general were less effective than DHA or EPA. Activated BCFA-treated cells expressed less of the cell surface Toll-like receptor 4 (TLR-4) compared to controls. These are the first data to show the reduction of pro-inflammatory markers in human cells mediated by BCFA. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Catecholamine-Directed Epithelial Cell Interactions with Bacteria in the Intestinal Mucosa.

    Science.gov (United States)

    Brown, David R

    2016-01-01

    The catecholamines epinephrine, norepinephrine and dopamine are present in or have access to mucous membranes in the digestive, respiratory and genitourinary tracts, which represent the first sites of microbial colonization and infection within the body. Epithelial cells at mucosal surfaces establish and maintain symbiotic microbial communities and serve as the initial cellular point of contact for pathogens with the animal host. These cells express receptors that are capable of detecting and responding to microbe-associated molecular patterns and in most host species express G protein-coupled receptors for catecholamines. Although it is increasingly recognized that substances produced and released from nerves and endocrine cells can exert immuno-modulatory actions at mucosal sites, there have been few investigations focused specifically on the catecholaminergic modulation of interactions between the mucosal epithelium and bacteria or other mucosa-associated microorganisms. The potential biomedical importance of this phenomenon cannot be understated. For example, psychological stress or other conditions that activate the sympathetic nervous system to release epinephrine and norepinephrine may act to produce short-term changes in luminal and mucosal microbial communities or alter the course of a bacterial infection. This chapter will briefly review this developing and important research area of mucosa-microbe interactions with a focus on intestinal host defense.

  16. The Carcinogenic Agent Azoxymethane (AOM) Enhances Early Inflammation-induced Colon Crypt Pathology

    DEFF Research Database (Denmark)

    Venning, Freja Albjerg; Claesson, Mogens Helweg; Kissow, Hannelouise

    2013-01-01

    mice and SCID mice with transfer colitis. AOM by itself did result in neither weight loss nor inflammation although treatment affected crypt widths and numbers. Although AOM together with T cell transfer did not increase the level of gut inflammation including COX-2 expression, AOM increased crypt......Severe combined immunodeficiency (SCID) mice transplanted with CD4+ T cells depleted of CD25+ regulatory T cells develop colitis within 2-3 weeks after the T cell transfer. In the present study we studied the effect of the carcinogen azoxymethane (AOM) on the colon crypt pathology of normal SCID...... changes associated with colon inflammation such as a decline in crypt numbers and an increase in crypts width throughout the large intestine. Thus it appears that AOM lower the threshold level for inflammation-induced changes which potentially may lead to neoplasia....

  17. 腐胺和脯氨酸对哺乳期仔猪空肠绒毛-隐窝轴上皮细胞的多胺代谢及Wnt信号通路的影响%Impact of Putrescine and Proline on Suckling Piglet Jejunum Villus-crypt Axis Epithelial Polyamine Metabolism and Wnt Signal Pathway

    Institute of Scientific and Technical Information of China (English)

    王小城; 熊霞; 杨焕胜; 高巍; 龚敏; 印遇龙

    2015-01-01

    differentiated epithelial cells of jejunum in sucking piglet and promoted the polyamine metabolism, however, no statistically significant effect was observed on crypt cell. In addition, exogenous putrescine and proline promote differentiation in the intestinal epithelial cells by Wnt signaling pathways.%【目的】研究腐胺和脯氨酸对哺乳期仔猪空肠绒毛-隐窝轴上皮细胞的多胺(腐胺、亚精胺和精胺)代谢、Wnt信号通路关键基因的mRNA相对表达量的影响。【方法】选取18头0日龄的刚出生的三元杂交(长白×大白×杜洛克)仔猪,随机配对分成3组,每组6个重复,每个重复1头猪,对照组,腐胺组和脯氨酸组,分别灌喂等体积的生理盐水,5 mg·kg-1体重添加剂量的腐胺和25 mg·kg-1体重添加剂量的脯氨酸,到14日龄断奶,断奶后3 d屠宰,分离空肠绒毛-隐窝轴的3个不同分化程度(绒毛顶端,绒毛中段和隐窝)的细胞,分别为F1,F2, F3。高效液相色谱法测定F1,F2,F3中的多胺浓度,RT-PCR测定多胺代谢途径中的相关基因以及Wnt信号通路中关键基因的mRNA相对表达量。【结果】1、在绒毛顶端细胞F1中,与对照组相比,脯氨酸组的腐胺、亚精胺、精胺的浓度均显著增加(P<0.05),而腐胺组的多胺均无显著差异(P>0.05);在绒毛中段细胞F2中,除了腐胺的含量无显著差异外,脯氨酸组和腐胺组的亚精胺、精胺的浓度均显著高于对照组(P<0.05),且脯氨酸组的亚精胺和精胺的浓度均显著高于腐胺组(P<0.05);在隐窝底端细胞F3中,腐胺组和脯氨酸组的腐胺、亚精胺、精胺浓度与对照组的浓度差异均不显著(P>0.05)。2、鸟氨酸脱羧酶(ODC)基因在绒毛顶端上皮细胞 F1中的 mRNA表达量,腐胺组显著高于脯氨酸组和对照组(P<0.05);精氨酸酶(arginase)在F2中的mRNA表达量,脯氨酸组显著高

  18. 鸡小肠上皮细胞的分离培养与鉴定%Culture of Chicken Intestine Epithelial Cells in vitro and its Characterization

    Institute of Scientific and Technical Information of China (English)

    李艳; 彭春燕; 梁榕旺; 赵国琦; 金晓君

    2011-01-01

    选择组织块法分离培养鸡小肠上皮细胞(intestinal epithelial cells,IEC),采用机械刮除法和相差消化-相差贴壁法纯化细胞,0.05%的Trypsin-EDTA对获得的IEC进行消化传代,免疫细胞化学法鉴定IEC.结果表明,组织块培养法可分离出活性较强的IEC,并获得纯化的上皮细胞;形态学和免疫细胞化学法检测显示获得的细胞表面抗原呈阳性,鉴定为IEC;纯化的IEC可在体外稳定传代.%In this study,we selected tissue culture method to isolation chicken intestinal epithelial cells (IEC), using curetrage, phase contrast digest and adherence methods to purify cells, with 0.05 % Trypsin to digest and passage, immunocytochemical method to identify intestinal epithelial cells.The results showed that hadro-activity intestinal epithelial cells could be dissociated by tissue culture method, and obtain purified intestine epithelium.Morphology and immunocytochemical method showed that intestinal epithelial cells surface antigen demonstrate masculine, and purified intestine epithelium could be passaged in vitro.

  19. Lipopolysaccharide binding protein and serum amyloid A secretion by human intestinal epithelial cells during the acute phase response.

    Science.gov (United States)

    Vreugdenhil, A C; Dentener, M A; Snoek, A M; Greve, J W; Buurman, W A

    1999-09-01

    The acute phase proteins LPS binding protein (LBP) and serum amyloid A (SAA) are produced by the liver and are present in the circulation. Both proteins have been shown to participate in the immune response to endotoxins. The intestinal mucosa forms a large surface that is continuously exposed to these microbial products. By secretion of antimicrobial and immunomodulating agents, the intestinal epithelium contributes to the defense against bacteria and their products. The aim of this study was to explore the influence of the inflammatory mediators TNF-alpha, IL-6, and IL-1beta on the release of LBP and SAA by intestinal epithelial cells (IEC). In addition, the induction of LBP and SAA release by cell lines of intestinal epithelial cells and hepatic cells was compared. The data obtained show that in addition to liver cells, IEC also expressed LBP mRNA and released bioactive LBP and SAA upon stimulation. Regulation of LBP and SAA release by IEC and hepatocytes was typical for class 1 acute phase proteins, although differences in regulation between the cell types were observed. Endotoxin did not induce LBP and SAA release. Glucocorticoids were demonstrated to strongly enhance the cytokine-induced release of LBP and SAA by IEC, corresponding to hepatocytes. The data from this study, which imply that human IEC can produce LBP and SAA, suggest a role for these proteins in the local defense mechanism of the gut to endotoxin. Furthermore, the results demonstrate that tissues other than the liver are involved in the acute phase response.

  20. Saccharomyces cerevisiae decreases inflammatory responses induced by F4+ enterotoxigenic Escherichia coli in porcine intestinal epithelial cells.

    Science.gov (United States)

    Zanello, Galliano; Meurens, François; Berri, Mustapha; Chevaleyre, Claire; Melo, Sandrine; Auclair, Eric; Salmon, Henri

    2011-05-15

    Probiotic yeasts may provide protection against intestinal inflammation induced by enteric pathogens. In piglets, infection with F4+ enterotoxigenic Escherichia coli (ETEC) leads to inflammation, diarrhea and intestinal damage. In this study, we investigated whether the yeast strains Saccharomyces cerevisiae (Sc, strain CNCM I-3856) and S. cerevisiae variety boulardii (Sb, strain CNCM I-3799) decreased the expression of pro-inflammatory cytokines and chemokines in intestinal epithelial IPI-2I cells cultured with F4+ ETEC. Results showed that viable Sc inhibited the ETEC-induced TNF-α gene expression whereas Sb did not. In contrast, killed Sc failed to inhibit the expression of pro-inflammatory genes. This inhibition was dependent on secreted soluble factors. Sc culture supernatant decreased the TNF-α, IL-1α, IL-6, IL-8, CXCL2 and CCL20 ETEC-induced mRNA. Furthermore, Sc culture supernatant filtrated fraction yeast strains onto inflammation.

  1. Gene regulation of intestinal porcine epithelial cells IPEC-J2 is dependent on the site of deoxynivalenol toxicological action.

    Directory of Open Access Journals (Sweden)

    Anne-Kathrin Diesing

    Full Text Available The intestinal epithelial cell layer represents the border between the luminal and systemic side of the gut. The decision between absorption and exclusion of substances is the quintessential function of the gut and varies along the gut axis. Consequently, potentially toxic substances may reach the basolateral domain of the epithelial cell layer via blood stream. The mycotoxin deoxynivalenol (DON is a Fusarium derived secondary metabolite known to enter the blood stream and displaying a striking toxicity on the basolateral side of polarised epithelial cell layers in vitro. Here we analysed potential mechanisms of apical and basolateral DON toxicity reflected in the gene expression. We used the jejunum-derived, polarised intestinal porcine epithelial cell line IPEC-J2 as an in vitro cell culture model. Luminal and systemic DON challenge of the epithelial cell layer was mimicked by a DON application from the apical or basolateral compartment of membrane inserts for 72 h. We compared the genome-wide gene expression of untreated and DON-treated IPEC-J2 cells with the GeneChip® Porcine Genome Array of Affymetrix. Low basolateral DON (200 ng/mL application triggered 10 times more gene transcripts in comparison to the corresponding apical application (2539 versus 267 despite the intactness of the challenged cell layer as measured by transepithelial electrical resistance. Analysis of the regulated genes by bioinformatic resource DAVID identified several groups of biochemical pathways modulated by concentration and orientation of DON application. Selected genes representing pathways of the cellular metabolism, information processing and structural design were analysed in detail by quantitative PCR. Our findings clearly show that apical and basolateral challenge of epithelial cell layers trigger different gene response profiles paralleled with a higher susceptibility towards basolateral challenge. The evaluation of toxicological potentials of mycotoxins

  2. Differential Effects of TNF (TNFSF2) and IFN-gamma on Intestinal Epithelial Cell Morphogenesis and Barrier Function in Three-Dimensional Culture

    NARCIS (Netherlands)

    Juuti-Uusitalo, Kati; Klunder, Leon J.; Sjollema, Klaas A.; Mackovicova, Katarina; Ohgaki, Ryuichi; Hoekstra, Dick; Dekker, Jan; van Ijzendoorn, Sven C. D.

    2011-01-01

    Background: The cytokines TNF (TNFSF2) and IFN gamma are important mediators of inflammatory bowel diseases and contribute to enhanced intestinal epithelial permeability by stimulating apoptosis and/or disrupting tight junctions. Apoptosis and tight junctions are also important for epithelial tissue

  3. Differential regulation of porcine beta-defensins 1 and 2 upon Salmonella infection in the intestinal epithelial cell line IPI-2I

    NARCIS (Netherlands)

    Veldhuizen, Edwin J A; Hendriks, Henno G C J M; Hogenkamp, Astrid; van Dijk, Albert; Gaastra, Wim; Tooten, Peter C J; Haagsman, Henk P

    2006-01-01

    Intestinal epithelial cells represent the first line of defence against pathogenic bacteria in the lumen of the gut. Besides acting as a physical barrier, epithelial cells orchestrate the immune response through the production of several innate immune mediator molecules including beta-defensins. Her

  4. A lactobacillus rhamnosus GG-derived soluble protein, p40, stimulates ligand release from intestinal epithelial cells to transactivate epidermal growth factor receptor

    Science.gov (United States)

    Protein p40, a Lactobacillus rhamnosus GG (LGG)-derived soluble protein, ameliorates intestinal injury and colitis, reduces apoptosis and preserves barrier function by activation of EGF receptor (EGFR) in intestinal epithelial cells. The aim of this study was to determine the mechanisms by which p40...

  5. Marked changes in endogenous antioxidant expression precede vitamin A, C and E-protectable, radiation-induced reductions in small intestinal nutrient transport

    Science.gov (United States)

    Roche, Marjolaine; Kemp, Francis W; Agrawal, Amit; Attanasio, Alicia; Neti, Prasad VSV; Howell, Roger W; Ferraris, Ronaldo P

    2010-01-01

    Rapidly proliferating epithelial crypt cells of the small intestine are susceptible to radiation-induced oxidative stress, yet there is a dearth of data linking this stress to expression of antioxidant enzymes and to alterations of intestinal nutrient absorption. We previously showed that 5 – 14 d after acute γ-irradiation, intestinal sugar absorption decreased without change in antioxidant enzyme expression. In the present study, we measured antioxidant mRNA and protein expression in mouse intestines taken at early times postirradiation. Observed changes in antioxidant expression are characterized by a rapid decrease within 1 h postirradiation, followed by dramatic upregulation within 4 h, and then downregulation a few days later. The cell type and location expressing the greatest changes in levels of the oxidative stress marker 4HNE and in antioxidant enzymes are, respectively, epithelial cells responsible for nutrient absorption and the crypt region comprised mainly of undifferentiated cells. Consumption of a cocktail of antioxidant vitamins A, C and E, before irradiation, prevents reductions in transport of intestinal sugars, amino acids, bile acids and peptides. Ingestion of antioxidants may blunt radiation-induced decreases in nutrient transport, perhaps by reducing acute oxidative stress in crypt cells, thereby allowing the small intestine to retain its absorptive function when those cells migrate to the villus days after the insult. PMID:20970494

  6. Immunohistochemical detection of human intestinal spirochetosis.

    Science.gov (United States)

    Ogata, Sho; Shimizu, Ken; Oda, Tomohiro; Tominaga, Susumu; Nakanishi, Kuniaki

    2016-12-01

    Human intestinal spirochetosis (HIS) is a colorectal infection by Brachyspira species of spiral bacteria. Immunohistochemical cross-reaction to an antibody for Treponema pallidum aids its histologic diagnosis. This study's aim was to analyze the immunohistochemical characteristics of HIS. In this analysis, on 223 specimens from 83 HIS cases, we focused on so-called fringe formation (a histologic hallmark of HIS), spiral organisms within mucus or within crypts, and strong immunopositive materials in the mucosa, together with their location and the types of lesions. Fringe formation was found in 81.6% of all specimens and spiral organisms within mucus or within crypts in 97.3% and 57.0%, respectively. Strong immunopositive materials were observed in the surface epithelial layer in 87.9%, in the subepithelial layer in 94.6%, and in deeper mucosa in 2.2% of all specimens. The positive rates in conventional adenomas (24.0%, n = 146) and hyperplastic nodules (100%, n = 17) were each different from that found in inflammation (70.8%, n = 24), and spiral organisms were seen more frequently in the right-side large intestine than in the left (within mucus, 100%, n = 104 versus 95.0%, n = 119; within crypts, 65.4%, n = 104 versus 49.6%, n = 119). Thus, immunohistochemistry was effective not only in supporting the diagnosis of HIS but also in highlighting spiral organisms within mucus or crypts that were invisible in routine histology. Possibly, these spiral organisms may spread throughout the entire large intestine, although there is a potential problem with antibody specificity.

  7. Altered intestinal microbial flora and impaired epithelial barrier structure and function in CKD: the nature, mechanisms, consequences and potential treatment.

    Science.gov (United States)

    Vaziri, Nosratola D; Zhao, Ying-Yong; Pahl, Madeleine V

    2016-05-01

    Chronic kidney disease (CKD) results in systemic inflammation and oxidative stress which play a central role in CKD progression and its adverse consequences. Although many of the causes and consequences of oxidative stress and inflammation in CKD have been extensively explored, little attention had been paid to the intestine and its microbial flora as a potential source of these problems. Our recent studies have revealed significant disruption of the colonic, ileal, jejunal and gastric epithelial tight junction in different models of CKD in rats. Moreover, the disruption of the epithelial barrier structure and function found in uremic animals was replicated in cultured human colonocytes exposed to uremic human plasma in vitro We have further found significant changes in the composition and function of colonic bacterial flora in humans and animals with advanced CKD. Together, uremia-induced impairment of the intestinal epithelial barrier structure and function and changes in composition of the gut microbiome contribute to the systemic inflammation and uremic toxicity by accommodating the translocation of endotoxin, microbial fragments and other noxious luminal products in the circulation. In addition, colonic bacteria are the main source of several well-known pro-inflammatory uremic toxins such as indoxyl sulfate, p-cresol sulfate, trimethylamine-N-oxide and many as-yet unidentified retained compounds in end-stage renal disease patients. This review is intended to provide an overview of the effects of CKD on the gut microbiome and intestinal epithelial barrier structure and their role in the pathogenesis of systemic inflammation and uremic toxicity. In addition, potential interventions aimed at mitigating these abnormalities are briefly discussed.

  8. Glial cell line-derived neurotrophic factor promotes barrier maturation and wound healing in intestinal epithelial cells in vitro.

    Science.gov (United States)

    Meir, Michael; Flemming, Sven; Burkard, Natalie; Bergauer, Lisa; Metzger, Marco; Germer, Christoph-Thomas; Schlegel, Nicolas

    2015-10-15

    Recent data suggest that neurotrophic factors from the enteric nervous system are involved in intestinal epithelial barrier regulation. In this context the glial cell line-derived neurotrophic factor (GDNF) was shown to affect gut barrier properties in vivo directly or indirectly by largely undefined processes in a model of inflammatory bowel disease (IBD). We further investigated the potential role and mechanisms of GDNF in the regulation of intestinal barrier functions. Immunostaining of human gut specimen showed positive GDNF staining in enteric neuronal plexus and in enterocytes. In Western blots of the intestinal epithelial cell lines Caco2 and HT29B6, significant amounts of GDNF were detected, suggesting that enterocytes represent an additional source of GDNF. Application of recombinant GDNF on Caco2 and HT29B6 cells for 24 h resulted in significant epithelial barrier stabilization in monolayers with immature barrier functions. Wound-healing assays showed a significantly faster closure of the wounded areas after GDNF application. GDNF augmented cAMP levels and led to significant inactivation of p38 MAPK in immature cells. Activation of p38 MAPK signaling by SB-202190 mimicked GDNF-induced barrier maturation, whereas the p38 MAPK activator anisomycin blocked GDNF-induced effects. Increasing cAMP levels had adverse effects on barrier maturation, as revealed by permeability measurements. However, increased cAMP augmented the proliferation rate in Caco2 cells, and GDNF-induced proliferation of epithelial cells was abrogated by the PKA inhibitor H89. Our data show that enterocytes represent an additional source of GDNF synthesis. GDNF contributes to wound healing in a cAMP/PKA-dependent manner and promotes barrier maturation in immature enterocytes cells by inactivation of p38 MAPK signaling.

  9. Interleukin-13 (IL-13)/IL-13 receptor alpha1 (IL-13Ralpha1) signaling regulates intestinal epithelial cystic fibrosis transmembrane conductance regulator channel-dependent Cl- secretion.

    Science.gov (United States)

    Wu, David; Ahrens, Richard; Osterfeld, Heather; Noah, Taeko K; Groschwitz, Katherine; Foster, Paul S; Steinbrecher, Kris A; Rothenberg, Marc E; Shroyer, Noah F; Matthaei, Klaus I; Finkelman, Fred D; Hogan, Simon P

    2011-04-15

    Interleukin-13 (IL-13) has been linked to the pathogenesis of inflammatory diseases of the gastrointestinal tract. It is postulated that IL-13 drives inflammatory lesions through the modulation of both hematopoietic and nonhematopoietic cell function in the intestine. To delineate the relevant contribution of elevated levels of intestinal IL-13 to intestinal structure and function, we generated an intestinal IL-13 transgenic mouse (iIL-13Tg). We show that constitutive overexpression of IL-13 in the small bowel induces modification of intestinal epithelial architecture (villus blunting, goblet cell hyperplasia, and increased epithelial proliferation) and epithelial function (altered basolateral → apical Cl(-) ion conductance). Pharmacological analyses in vitro and in vivo determined that elevated Cl(-) conductance is mediated by altered cystic fibrosis transmembrane conductance regulator expression and activity. Generation of iIL-13Tg/Il13rα1(-/-), iIL-13Tg/Il13rα2(-/-), and iIL-13Tg/Stat6(-/-) mice revealed that IL-13-mediated dysregulation of epithelial architecture and Cl(-) conductance is dependent on IL-13Rα1 and STAT-6. These observations demonstrate a central role for the IL-13/IL-13Rα1 pathway in the regulation of intestinal epithelial cell Cl(-) secretion via up-regulation of cystic fibrosis transmembrane conductance regulator, suggesting an important role for this pathway in secretory diarrhea.

  10. Transcriptome changes during intestinal cell differentiation

    DEFF Research Database (Denmark)

    Tadjali, Mehrdad; Seidelin, Jakob B; Olsen, Jørgen Lillelund

    2002-01-01

    The expression of 18149 genes have been analysed during the differentiation of the human intestinal cell line Caco-2. cDNA probes from undifferentiated and differentiated Caco-2 cells were separately hybridised to EST DNAs spotted in an array on a nylon membrane. A remarkable change...... in the transcriptome was observed during the differentiation of the Caco-2 cells. 8762 of the 18149 genes analysed were expressed above background level in the undifferentiated Caco-2 cells, whereas only 5767 genes were expressed above background in differentiated Caco-2 cells. This pattern of expression was caused...... by a general down-regulation of genes in the low abundance class. Similar results were found using mouse small intestinal crypt and villus cells, suggesting that the phenomenon also occurs in the intestine in vivo. The expression data were subsequently used in a search for markers for subsets of epithelial...

  11. Inhibition of p38 mitogen-activated protein kinase may decrease intestinal epithelial cell apoptosis and improve intestinal epithelial barrier function after ischemia- reperfusion injury

    Institute of Scientific and Technical Information of China (English)

    Shu-Yun Zheng; Xiao-Bing Fu; Jian-Guo Xu; Jing-Yu Zhao; Tong-Zhu Sun; Wei Chen

    2005-01-01

    AIM: To investigate the role of p38 mitogen-activated protein kinase in rat small intestine after ischemia-reperfusion (I/R)insult and the relationship between activation of p38 MAPK and apoptotic cell death of intestine.METHODS: Ninety Wistar rats were divided randomly into three groups, namely sham-operated group (C), I/R vehicle group (R) and SB203580 pre-treated group(S).In groups R and S, the superior mesenteric artery(SMA)was separated and occluded for 45 min, then released for reperfusion for0.25, 0.5, 1, 2, 6, 12 and 24 h. In group C, SMA was separated without occlusion. Plasma D-lactate levels were examined and histological changes were observed under a light microscope. The activity of p38 MAPK was determined by Western immunoblotting and apoptotic cells were detected by the terminal deoxynucleotidyl transferase (TdT)-mediated dUDP-biotin nick end labeling (TUNEL).RESULTS: Intestinal ischemia followed by reperfusion activated p38 MAPK, and the maximal level of activation (7.3-fold vs sham-operated group) was reached 30 min after I/R. Treatment with SB 203580, a p38 MAPK inhibitor,reduced intestinal apoptosis (26.72±3.39% vs62.50±3.08%in I/R vehicle, P<0.01) and decreased plasma D-lactate level (0.78±0.15 mmol/L in I/R vehicle vs0.42±0.17 mmol/L in SB-treated group) and improved post-ischemic intestinal histological damage.CONCLUSION: p38 MAPK plays a crucial role in the signal transduction pathway mediating post-ischemic intestinal apoptosis, and inhibition of p38 MAPK may attenuate ischemia-reperfusion injury.

  12. VSL#3 Probiotic Differently Influence IEC-6 Intestinal Epithelial Cell Status and Function.

    Science.gov (United States)

    Cinque, Benedetta; La Torre, Cristina; Lombardi, Francesca; Palumbo, Paola; Evtoski, Zoran; Santini, Silvano Jr; Falone, Stefano; Cimini, Annamaria; Amicarelli, Fernanda; Cifone, Maria Grazia

    2017-01-21

    The data here reported introduce the wound-healing assay as a tool for testing probiotics aimed at protecting gastrointestinal mucosal surfaces and to verify the consistency of their manufacturing. At the scope, we compared the in vitro effects of two multi-strain high concentration formulations both commercialized under the same brand VSL#3 but sourced from different production sites (USA and Italy) on a non-transformed small-intestinal epithelial cell line, IEC-6. The effects on cellular morphology, viability, migration, and H2 O2 -induced damage, were assessed before and after the treatment with both VSL#3 formulations. While the USA-sourced product ("USA-made") VSL#3 did not affect monolayer morphology and cellular density, the addition of bacteria from the Italy-derived product ("Italy-made") VSL#3 caused clear morphological cell damage and strongly reduced cellularity. The treatment with "USA-made" lysate led to a higher rate of wounded monolayer healing, while the addition of "Italy-made" bacterial lysate did not influence the closure rate as compared to untreated cells. While lysates from "USA-made" VSL#3 clearly enhanced the formation of elongated and aligned stress fibers, "Italy-made" lysates had not similar effect. "USA-made" lysate was able to cause a total inhibition of H2 O2 -induced cytotoxic effect whereas "Italy-made" VSL#3 lysate was unable to protect IEC-6 cells from H2 O2 -induced damage. ROS generation was also differently influenced, thus supporting the hypotesis of a protective action of "USA-made" VSL#3 lysates, as well as the idea that "Italy-made" formulation was unable to prevent significantly the H2 O2 -induced oxidative stress. This article is protected by copyright. All rights reserved.

  13. Vitamin D differentially regulates Salmonella-induced intestine epithelial autophagy and interleukin-1β expression

    Science.gov (United States)

    Huang, Fu-Chen

    2016-01-01

    AIM To investigate the effects of active vitamin D3 on autophagy and interleukin (IL)-1β expression in Salmonella-infected intestinal epithelial cells (IECs). METHODS Caco-2 cells, NOD2 siRNA-, Atg16L1 siRNA- or vitamin D receptor (VDR) siRNA-transfected Caco-2 cells were pretreated with 1,25-dihydroxyvitamin D3 (1,25D3), and then infected by wild-type S. typhimurium strain SL1344. The conversion of LC3-I to LC3-II was detected by Western blot analysis and LC3+ autophagosome was analyzed by immunofluorescence. Caco-2 cells or VDR siRNA-transfected cells were pretreated with 1,25D3, and then infected by SL1344. Membrane protein and total RNA were analyzed by Western blot and RT-PCR for VDR and Atg16L1 protein and mRNA expression, respectively. Atg16L1 siRNA-transfected Caco-2 cells were pretreated by 1,25D3 and then infected with SL1344. Total RNA was analyzed by RT-PCR for IL-1β mRNA expression. RESULTS The active form of vitamin D, 1,25D3, showed enhanced VDR-mediated Atg16L1 mRNA expression, membranous Atg16L1 protein expression leading to enhanced autophagic LC3II protein expression and LC3 punctae in Salmonella-infected Caco-2 cells which was counteracted by Atg16L1 and VDR siRNA, but Atg16L1 mediated suppression of IL-1β expression. Thus, active vitamin D may enhance autophagy but suppress inflammatory IL-1β expression in Salmonella-infected IECs. CONCLUSION Active vitamin D might enhance autophagic clearance of Salmonella infection, while modulation of inflammatory responses prevents the host from detrimental effects of overwhelming inflammation. PMID:28058015

  14. FRET-based dual-emission and pH-responsive nanocarriers for enhanced delivery of protein across intestinal epithelial cell barrier.

    Science.gov (United States)

    Lu, Kun-Ying; Lin, Cheng-Wei; Hsu, Chun-Hua; Ho, Yi-Cheng; Chuang, Er-Yuan; Sung, Hsing-Wen; Mi, Fwu-Long

    2014-10-22

    The oral route is a convenient and commonly employed way for drug delivery. However, therapeutic proteins have poor bioavailability upon oral administration due to the impermeable barrier from intestinal epithelial tight junction (TJ). Moreover, the pH of the small intestine varies among different regions of the intestinal tract where digestion and absorption occur at different levels. In this study, a tunable dual-emitting and pH-responsive nanocarrier that can alter the fluorescent color and emission intensity in response to pH changes and can trigger the opening of intestinal epithelial TJ at different levels were developed from chitosan-N-arginine and poly(γ-glutamic acid)-taurine conjugates. As pH increased from 6.0 to 8.0, the binding affinity of the oppositely charged polyions decreased, whereas the ratio of the intensity of the donor-to-acceptor emission intensity (ID/IA) increased by 27-fold. The fluorescent and pH-responsive nanocarrier was able to monitor the pH change of intestinal environment and to control the release of an anti-angiogenic protein in response to the pH gradient. The nanocarrier triggered the opening of intestinal epithelial TJ and consequently enhanced the permeation of the released protein through the intestinal epithelial barrier model (Caco-2 cell monolayer) to inhibit tube formation of human umbilical vein endothelial cells.

  15. Role of protein tyrosine kinase in the effect of IP6 on IL-8 secretion in intestinal epithelial cells.

    Science.gov (United States)

    Wawszczyk, Joanna; Orchel, Arkadiusz; Kapral, Małgorzata; Wéglarz, Ludmiła

    2013-01-01

    Phytic acid (IP6) is a major fiber-associated component of a diet physiologically present in human intestines. Studies showed that this phytochemical can modulate immune functions of intestinal epithelium through regulation of proinflammatory cytokines secretion but mechanisms underlying these cellular response to IP6 have weakly been examined, as yet. The aim of this study was to determine the role of protein tyrosine kinase (PTK) in secretion of IL-8, a central proinflammatory cytokine, by unstimulated and IL-1beta-stimulated intestinal epithelial cells Caco-2 treated with IP6 (1 and 2.5 mM). To study the involvement of PTK signal pathway in IL-8 secretion, inhibitors of phosphotyrosine phosphatase (sodium orthovanadate, OV) and tyrosine kinase (genistein, GEN) were incubated with Caco-2 cells prior to IP6 treatment. IP6 had suppressive effect on basal and IL-1beta-stimulated IL-8 secretion by cells. The effect of OV on IL-8 release by cells treated with IP6 was different under constitutive and stimulated conditions. Secretion of IL-8 was significantly down-regulated in cells with GEN and GEN plus IP6 treatment. In addition, total PTK activity in both unstimulated and IL-1beta stimulated cells was determined in the presence of IP6. The results suggest that physiological intestinal concentrations of IP6 may have an inhibitory effect on IL-8 secretion by Caco-2 cells and one of the mechanisms of its action is the inhibition of PTK signaling cascade. The study revealed for the first time that PTKs could be one of the molecular targets for IP6 effects in the intestinal epithelial cells.

  16. Quantification of Crypt and Stem Cell Evolution in the Normal and Neoplastic Human Colon

    Directory of Open Access Journals (Sweden)

    Ann-Marie Baker

    2014-08-01

    Full Text Available Human intestinal stem cell and crypt dynamics remain poorly characterized because transgenic lineage-tracing methods are impractical in humans. Here, we have circumvented this problem by quantitatively using somatic mtDNA mutations to trace clonal lineages. By analyzing clonal imprints on the walls of colonic crypts, we show that human intestinal stem cells conform to one-dimensional neutral drift dynamics with a “functional” stem cell number of five to six in both normal patients and individuals with familial adenomatous polyposis (germline APC−/+. Furthermore, we show that, in adenomatous crypts (APC−/−, there is a proportionate increase in both functional stem cell number and the loss/replacement rate. Finally, by analyzing fields of mtDNA mutant crypts, we show that a normal colon crypt divides around once every 30–40 years, and the division rate is increased in adenomas by at least an order of magnitude. These data provide in vivo quantification of human intestinal stem cell and crypt dynamics.

  17. Oxymatrine improves intestinal epithelial barrier function involving NF-κB-mediated signaling pathway in CCl4-induced cirrhotic rats.

    Directory of Open Access Journals (Sweden)

    Jian-Bo Wen

    Full Text Available Accumulating evidence suggests that intestinal epithelial barrier dysfunction plays an important role in the pathogenesis of hepatic cirrhosis and its complications such as gastrointestinal injury and hepatic encephalopathy. To date, there is no cure for cirrhosis-associated intestinal mucosal lesion and ulcer. This study aimed to investigate the effect of oxymatrine on intestinal epithelial barrier function and the underlying mechanism in carbon tetrachloride (CCl4-induced cirrhotic rats. Thirty CCl4-induced cirrhotic rats were randomly divided into treatment group, which received oxymatrine treatment (63 mg/kg, and non-treatment group, which received the same dose of 5% glucose solution (vehicle. The blank group (n = 10 healthy rats received no treatment. Terminal ileal samples were collected for histopathological examination. The expression level of nuclear factor-κB (NF-κB p65 in ileal tissue was evaluated by immunohistochemistry. The gene and protein expression levels of tumor necrosis factor-α (TNF-α and interleukin 6 (IL-6 in ileal tissues were analyzed by reverse-transcriptase polymerase chain reaction (RT-PCR and enzyme-linked immunosorbent assay (ELISA, respectively. Additionally, plasma endotoxin level was determined. In comparison to the blank group, a significant alteration in the morphology of intestinal mucosal villi in the non-treatment group was observed. The intestinal mucosal villi were atrophic, shorter, and fractured, and inflammatory cells were infiltrated into the lamina propria and muscular layer. Besides, serious swell of villi and loose structure of mucous membrane were observed. Oxymatrine reversed the CCl4-induced histological changes and restored intestinal barrier integrity. Moreover, oxymatrine reduced the protein expression level of NF-κB p65, TNF-α, and IL-6, which were elevated in the vehicle-treated group. In addition, the serum endotoxin level was significantly decreased after oxymatrine treatment in

  18. INFLUENCE OF SEX AND EGG WEIGHT ON VILLUS AND CRYPT SIZE OF THE SMALL INTESTINE IN BROILER EMBRYOS AND CHICKS INFLUÊNCIA DO SEXO E PESO DOS OVOS SOBRE A ALTURA DOS VILOS E PROFUNDIDADE DAS CRIPTAS DO INTESTINO DELGADO DE EMBRIÕES E PINTOS DE CORTE

    Directory of Open Access Journals (Sweden)

    Euclidez Braga Malheiros

    2008-10-01

    Full Text Available

    The influence of sex and egg weight on small intestine villi height and crypt depth was analyzed at 18 d of incubation, at hatching, and 7 days post-hatch. Amounts of duodenum. jejunum and ileum were removed and fixed in Bouin solution for 24 hours. After rinse in 5% ethanol, the amounts were dehydrated in a graded alcohol series up to absolute ethanol (70%, 80%, 90% and 100%, diafanized in absolute xylene and embedded in paraplast. Sections were stained with hematoxylin and eosin. Dta were submitted to analysis of variance. And significant treatment means were separated by Tukey´s test (p<0.05. In all three analyzed ages, birds from heavy eggs presented the heaviest body weights. At 7 days of age, female chicks were heavier than males. In the jejunum, villi were higher in male embryos as compared to female embryos, whereas in the ileum, villi were higher in females as compared to males. In the three intestinal segments, crypts were deeper in males than in females. Duodenum, jejunum, and ileum villi height and jejunum crypt depth were higher in embryos derived from heavy eggs. At hatching, duodenal crypts were deeper in male than in female chicks, while jejunum and ileum crypts were deeper in female chicks. Newly-hatched chicks from heavy eggs presented the highest villi. In the three intestinal segments, crypt was shallower in chicks hatched from light as compared to heavy eggs. At 7 days of age, jejunum villi were higher in male than in female chicks, whereas crypts were deeper in females in all intestinal segments. Chicks hatched from heavy eggs presented the highest jejunum and ileum villi, and the deepest ileum depth. The results of this study show that body weight and the intestinal mucosa are influenced by sex and egg weight, and that females from heavy eggs were the heaviest chicks, and their jejunum and ileum mucosa presented the highest growth.

    KEY WORDS: Broiler embryos, chicks

  19. Colonic miRNA expression/secretion, regulated by intestinal epithelial PepT1, plays an important role in cell-to-cell communication during colitis.

    Directory of Open Access Journals (Sweden)

    Saravanan Ayyadurai

    Full Text Available PepT1 is a member of the proton-oligopeptide cotransporter family SLC15, which mediates the transport of di/tripeptides from intestinal lumen into epithelial cells. MicroRNAs (miRNAs, a small noncoding RNAs (21-23 nucleotides, post-transcriptionally regulate gene expression by binding to the 3'-untranslated regions (UTRs of their target mRNAs. Although the role of most miRNAs remains elusive, they have been implicated in vital cellular functions such as intestinal epithelial cells differentiation, proliferation, and apoptosis. In the present study, we investigated the effect of intestinal epithelial PepT1 expression on microRNA (miRNA expression/secretion in the colons of control mice and in mice with experimentally induced colonic inflammation (colitis. The colonic miRNA expression was deregulated in both colitis and control mice but the deregulation of miRNA expression/secretion was specific to colonic tissue and did not affect other tissues such as spleen and liver. Intestinal epithelial PepT1-dependent deregulation of colonic miRNA expression not only affects epithelial cells but also other cell types, such as intestinal macrophages. Importantly, we found the miRNA 23b which was known to be involved in inflammatory bowel disease was secreted and transported between cells to impose a gene-silencing effect on recipient intestinal macrophages. Based on our data, we may conclude that the expression of a specific protein, PepT1, in the intestine affects local miRNA expression/secretion in the colon on a tissue specific manner and may play an important role during the induction and progression of colitis. Colonic miRNA expression/secretion, regulated by intestinal epithelial PepT1, could play a crucial role in cell-to-cell communication during colitis.

  20. Cytokine responses of human intestinal epithelial-like Caco-2 cells to the nonpathogenic bacterium Bacillus subtilis (natto).

    Science.gov (United States)

    Hosoi, Tomohiro; Hirose, Rieko; Saegusa, Shizue; Ametani, Akio; Kiuchi, Kan; Kaminogawa, Shuichi

    2003-05-15

    Intestinal epithelial cells produce cytokines in response to pathogenic bacteria. However, cellular responses of these cells to nonpathogenic strains, such as Bacillus subtilis, are yet to be determined. In this study, we investigate whether epithelial-like human colon carcinoma Caco-2 cells produce cytokines in response to B. subtilis or B. subtilis (natto). The latter strain is utilized for manufacturing the fermented soy food "natto". Live cells of nonpathogenic B. subtilis JCM 1465(T), B. subtilis (natto) and E. coli JCM 1649(T), as well as pathogenic S. enteritidis JCM 1652 and P. aeruginosa JCM 5516 strains, induced secretion of interleukin-6 (IL-6) and/or IL-8, but not IL-7, IL-15 or tumor necrosis factor alpha (TNF-alpha). Transepithelial electrical resistance (TER) of Caco-2 cell monolayers cultured with E. coli, S. enteritidis or P. aeruginosa decreased more rapidly than that of cells cultured with B. subtilis or B. subtilis (natto). The amounts of cytokine induced by B. subtilis (natto) cells were strain-dependent. Moreover, B. subtilis (natto) cells subjected to hydrochloric acid treatment, but not autoclaving, induced a higher secretion of IL-6 and IL-8 than intact cells. Tyrosine kinase inhibitors, including AG126 and genistein, suppressed cytokine secretion. Our results suggest that the nonpathogenic B. subtilis (natto) bacterium induces cytokine responses in intestinal epithelial cells via activation of an intracellular signaling pathway, such as that of nuclear factor-kappa B (NF-kappaB).

  1. Cell-permeable intrinsic cellular inhibitors of apoptosis protect and rescue intestinal epithelial cells from radiation-induced cell death.

    Science.gov (United States)

    Matsuzaki-Horibuchi, Shiori; Yasuda, Takeshi; Sakaguchi, Nagako; Yamaguchi, Yoshihiro; Akashi, Makoto

    2015-01-01

    One of the important mechanisms for gastrointestinal (GI) injury following high-dose radiation exposure is apoptosis of epithelial cells. X-linked inhibitor of apoptosis (XIAP) and cellular IAP2 (cIAP2) are intrinsic cellular inhibitors of apoptosis. In order to study the effects of exogenously added IAPs on apoptosis in intestinal epithelial cells, we constructed bacterial expression plasmids containing genes of XIAP (full-length, BIR2 domain and BIR3-RING domain with and without mutations of auto-ubiquitylation sites) and cIAP2 proteins fused to a protein-transduction domain (PTD) derived from HIV-1 Tat protein (TAT) and purified these cell-permeable recombinant proteins. When the TAT-conjugated IAPs were added to rat intestinal epithelial cells IEC6, these proteins were effectively delivered into the cells and inhibited apoptosis, even when added after irradiation. Our results suggest that PTD-mediated delivery of IAPs may have clinical potential, not only for radioprotection but also for rescuing the GI system from radiation injuries.

  2. Determination of tolerable fatty acids and cholera toxin concentrations using human intestinal epithelial cells and BALB/c mouse macrophages.

    Science.gov (United States)

    Tamari, Farshad; Tychowski, Joanna; Lorentzen, Laura

    2013-05-30

    The positive role of fatty acids in the prevention and alleviation of non-human and human diseases have been and continue to be extensively documented. These roles include influences on infectious and non-infectious diseases including prevention of inflammation as well as mucosal immunity to infectious diseases. Cholera is an acute intestinal illness caused by the bacterium Vibrio cholerae. It occurs in developing nations and if left untreated, can result in death. While vaccines for cholera exist, they are not always effective and other preventative methods are needed. We set out to determine tolerable concentrations of three fatty acids (oleic, linoleic and linolenic acids) and cholera toxin using mouse BALB/C macrophages and human intestinal epithelial cells, respectively. We solubilized the above fatty acids and used cell proliferation assays to determine the concentration ranges and specific concentrations of the fatty acids that are not detrimental to human intestinal epithelial cell viability. We solubilized cholera toxin and used it in an assay to determine the concentration ranges and specific concentrations of cholera toxin that do not statistically decrease cell viability in BALB/C macrophages. We found the optimum fatty acid concentrations to be between 1-5 ng/μl, and that for cholera toxin to be cholera infections.

  3. Alanyl-glutamine attenuates 5-fluorouracil-induced intestinal mucositis in apolipoprotein E-deficient mice

    Directory of Open Access Journals (Sweden)

    C.V. Araújo

    2015-06-01

    Full Text Available Apolipoprotein E (APOE=gene, apoE=protein is a known factor regulating the inflammatory response that may have regenerative effects during tissue recovery from injury. We investigated whether apoE deficiency reduces the healing effect of alanyl-glutamine (Ala-Gln treatment, a recognized gut-trophic nutrient, during tissue recovery after 5-FU-induced intestinal mucositis. APOE-knockout (APOE-/- and wild-type (APOE+/+ C57BL6J male and female mice (N=86 were given either Ala-Gln (100 mM or phosphate buffered saline (PBS by gavage 3 days before and 5 days after a 5-fluorouracil (5-FU challenge (450 mg/kg, via intraperitoneal injection. Mouse body weight was monitored daily. The 5-FU cytotoxic effect was evaluated by leukometry. Intestinal villus height, villus/crypt ratio, and villin expression were monitored to assess recovery of the intestinal absorptive surface area. Crypt length, mitotic, apoptotic, and necrotic crypt indexes, and quantitative real-time PCR for insulin-like growth factor-1 (IGF-1 and B-cell lymphoma 2 (Bcl-2 intestinal mRNA transcripts were used to evaluate intestinal epithelial cell turnover. 5-FU challenge caused significant weight loss and leukopenia (P<0.001 in both mouse strains, which was not improved by Ala-Gln. Villus blunting, crypt hyperplasia, and reduced villus/crypt ratio (P<0.05 were found in all 5-FU-challenged mice but not in PBS controls. Ala-Gln improved villus/crypt ratio, crypt length and mitotic index in all challenged mice, compared with PBS controls. Ala-Gln improved villus height only in APOE-/- mice. Crypt cell apoptosis and necrotic scores were increased in all mice challenged by 5-FU, compared with untreated controls. Those scores were significantly lower in Ala-Gln-treated APOE+/+ mice than in controls. Bcl-2 and IGF-1 mRNA transcripts were reduced only in the APOE-/--challenged mice. Altogether our findings suggest APOE-independent Ala-Gln regenerative effects after 5-FU challenge.

  4. Alanyl-glutamine attenuates 5-fluorouracil-induced intestinal mucositis in apolipoprotein E-deficient mice

    Energy Technology Data Exchange (ETDEWEB)

    Araújo, C.V. [Laboratório da Biologia da Cicatrização, Ontogenia e Nutrição de Tecidos, INCT - Instituto de Biomedicina do Semiárido Brasileiro, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, CE (Brazil); Lazzarotto, C.R. [Laboratório de Biologia Molecular e do Desenvolvimento, Universidade de Fortaleza, Fortaleza, CE (Brazil); Aquino, C.C.; Figueiredo, I.L.; Costa, T.B.; Oliveira Alves, L.A. de [Laboratório da Biologia da Cicatrização, Ontogenia e Nutrição de Tecidos, INCT - Instituto de Biomedicina do Semiárido Brasileiro, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, CE (Brazil); Ribeiro, R.A. [Laboratório da Inflamação e Câncer, INCT - Instituto de Biomedicina do Semiárido Brasileiro, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, CE (Brazil); Bertolini, L.R. [Laboratório de Biologia Molecular e do Desenvolvimento, Universidade de Fortaleza, Fortaleza, CE (Brazil); Lima, A.A.M. [Laboratório de Doenças Infecciosas, INCT - Instituto de Biomedicina do Semiárido Brasileiro, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, CE (Brazil); Brito, G.A.C. [Laboratório da Inflamação e Câncer, INCT - Instituto de Biomedicina do Semiárido Brasileiro, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, CE (Brazil); Oriá, R.B. [Laboratório da Biologia da Cicatrização, Ontogenia e Nutrição de Tecidos, INCT - Instituto de Biomedicina do Semiárido Brasileiro, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, CE (Brazil)

    2015-04-28

    Apolipoprotein E (APOE=gene, apoE=protein) is a known factor regulating the inflammatory response that may have regenerative effects during tissue recovery from injury. We investigated whether apoE deficiency reduces the healing effect of alanyl-glutamine (Ala-Gln) treatment, a recognized gut-trophic nutrient, during tissue recovery after 5-FU-induced intestinal mucositis. APOE-knockout (APOE{sup -/-}) and wild-type (APOE{sup +/+}) C57BL6J male and female mice (N=86) were given either Ala-Gln (100 mM) or phosphate buffered saline (PBS) by gavage 3 days before and 5 days after a 5-fluorouracil (5-FU) challenge (450 mg/kg, via intraperitoneal injection). Mouse body weight was monitored daily. The 5-FU cytotoxic effect was evaluated by leukometry. Intestinal villus height, villus/crypt ratio, and villin expression were monitored to assess recovery of the intestinal absorptive surface area. Crypt length, mitotic, apoptotic, and necrotic crypt indexes, and quantitative real-time PCR for insulin-like growth factor-1 (IGF-1) and B-cell lymphoma 2 (Bcl-2) intestinal mRNA transcripts were used to evaluate intestinal epithelial cell turnover. 5-FU challenge caused significant weight loss and leukopenia (P<0.001) in both mouse strains, which was not improved by Ala-Gln. Villus blunting, crypt hyperplasia, and reduced villus/crypt ratio (P<0.05) were found in all 5-FU-challenged mice but not in PBS controls. Ala-Gln improved villus/crypt ratio, crypt length and mitotic index in all challenged mice, compared with PBS controls. Ala-Gln improved villus height only in APOE{sup -/-} mice. Crypt cell apoptosis and necrotic scores were increased in all mice challenged by 5-FU, compared with untreated controls. Those scores were significantly lower in Ala-Gln-treated APOE{sup +/+} mice than in controls. Bcl-2 and IGF-1 mRNA transcripts were reduced only in the APOE{sup -/-}-challenged mice. Altogether our findings suggest APOE-independent Ala-Gln regenerative effects after 5-FU

  5. Bodies Folded in Migrant Crypts

    DEFF Research Database (Denmark)

    Galis, Vasilis; Tzokas, Spyros; Tympas, Aristotle

    2016-01-01

    and human migrants generates a dis/abled subject. In this context, dis/ability may be a cause or consequence of migration, both in physical/material (the folding of bodies in the crypt) and cultural/semiotic terms, and may become a barrier to accessing protection, to entering and/or crossing a country...

  6. Vascular Endothelial Growth Factor (VEGF) Bioavailability Regulates Angiogenesis and Intestinal Stem and Progenitor Cell Proliferation during Postnatal Small Intestinal Development

    Science.gov (United States)

    Holoyda, Kathleen A.; Hou, Xiaogang; Fowler, Kathryn L.; Grikscheit, Tracy C.

    2016-01-01

    Background Vascular endothelial growth factor (VEGF) is a highly conserved, master regulatory molecule required for endothelial cell proliferation, organization, migration and branching morphogenesis. Podocoryne carnea and drosophila, which lack endothelial cells and a vascular system, express VEGF homologs, indicating potential roles beyond angiogenesis and vasculogenesis. The role of VEGF in the development and homeostasis of the postnatal small intestine is unknown. We hypothesized regulating VEGF bioavailability in the postnatal small intestine would exhibit effects beyond the vasculature and influence epithelial cell stem/progenitor populations. Methods VEGF mutant mice were created that overexpressed VEGF in the brush border of epithelium via the villin promotor following doxycycline treatment. To decrease VEGF bioavailability, sFlt-1 mutant mice were generated that overexpressed the soluble VEGF receptor sFlt-1 upon doxycycline administration in the intestinal epithelium. Mice were analyzed after 21 days of doxycycline administration. Results Increased VEGF expression was confirmed by RT-qPCR and ELISA in the intestine of the VEGF mutants compared to littermates. The VEGF mutant duodenum demonstrated increased angiogenesis and vascular leak as compared to littermate controls. The VEGF mutant duodenum revealed taller villi and increased Ki-67-positive cells in the transit-amplifying zone with reduced Lgr5 expression. The duodenum of sFlt-1 mutants revealed shorter villi and longer crypts with reduced proliferation in the transit-amplifying zone, reduced expression of Dll1, Bmp4 and VE-cadherin, and increased expression of Sox9 and EphB2. Conclusions Manipulating VEGF bioavailability leads to profound effects on not only the intestinal vasculature, but epithelial stem and progenitor cells in the intestinal crypt. Elucidation of the crosstalk between VEGF signaling in the vasculature, mesenchyme and epithelial stem/progenitor cell populations may direct future

  7. Lactobacillus johnsonii N6.2 stimulates the innate immune response through Toll-like receptor 9 in Caco-2 cells and increases intestinal crypt Paneth cell number in biobreeding diabetes-prone rats.

    Science.gov (United States)

    Kingma, Sandra D K; Li, Nan; Sun, Frank; Valladares, Ricardo B; Neu, Joe; Lorca, Graciela L

    2011-06-01

    Lactobacillus johnsonii (Ljo) N6.2 has been shown to mitigate the development of type 1 diabetes when administered to diabetes-prone rats. The specific mechanisms underlying this observed response remain under investigation. The objective of this study was to assess the effect of Ljo N6.2 on mucosal inflammatory response using differentiated Caco-2 monolayers. The mRNA expression levels of CCL20, CXCL8, and CXCL10 chemokines were determined by qRT-PCR. Ljo at 10(11) CFU/L induced a strong response in all chemokines examined. To assess the specific host-signaling pathways involved, we performed RT-PCR amplification of Toll-like receptors (TLR) and nucleotide-binding oligomerization domain-like receptors. TLR7 and TLR9 expression levels were induced 4.2- and 9-fold, respectively, whereas other TLR and nucleotide-binding oligomerization domain receptors were not modified. A similar effect was observed in Caco-2 monolayers treated with Ljo cell-free extract or purified nucleic acids (NA). Increased levels of IFN type 1 and IFN regulators Stat1 and IRF7 followed the upregulation of TLR9. Activation of TLR9 was also evidenced by increased Frizzled 5 expression in Ljo-treated Caco-2 cells and an increase in the number of Paneth cells in Ljo-fed, diabetes-prone rats. These results are in agreement with the polarizing-tolerizing mechanism recently described in which the apical stimulation of TLR9 in intestinal epithelial cells leads to a higher state of immunologic alertness. Furthermore, these results suggest that live probiotics could be, in the future, replaced with select cellular components.

  8. Inhibitory effect of O-glycosylation inhibition on human intestinal epithelial cells Mucin 2 expression and bacteria adherence

    Directory of Open Access Journals (Sweden)

    Li-li SONG

    2013-11-01

    Full Text Available Objective To investigate the effect of O-glycosylation inhibition in intestinal epithelial cells on the expression of Mucin 2 (MUC2 and bacterial adherence. Methods Intestinal epithelial cells HT-29 and differentiated HT-29 cells (HT-29-Gal were treated with an inhibitor of O-glycosylation (benzyl-α-GalNAc, and then named as HT-29-OBN and HT-29-Gal-OBN, respectively. The mRNA and protein expression of MUC2 in HT-29, HT29-Gal, HT-29-OBN and HT-29-Gal-OBN were detected by real-time PCR and Western blotting. Then the four kinds of above cells were incubated with enteropathogenic Escherichia coli (EPEC or enterohemorrhagic Escherichia coli serotype O157:H7 (EHEC O157:H7. The bacteria were quantified by determining the colony forming unit (CFU following the plating of serial dilutions of the bacteria to evaluate the effect of benzyl-α-GalNAc on bacteria adherence. Results The results of real-time PCR and Western blotting showed that the mRNA and protein expression levels of MUC2 in HT-29-OBN and HT-29-Gal-OBN cells were significantly lower than those in the untreated cells HT-29 and HT-29-Gal (P<0.05. The bacterial adherence assay showed that the adherence of EPEC and EHEC O157:H7 to HT-29-OBN and HT-29-Gal-OBN cells significantly decreased compared with that to HT-29 and HT-29-Gal cells (P<0.05. Conclusion Inhibition of O-glycosylation in intestinal epithelial cells may reduce the bacteria adherence and MUC2 expression. DOI: 10.11855/j.issn.0577-7402.2013.10.009

  9. Cyclical DNA Methylation and Histone Changes Are Induced by LPS to Activate COX-2 in Human Intestinal Epithelial Cells

    Science.gov (United States)

    Brancaccio, Mariarita; Coretti, Lorena; Florio, Ermanno; Pezone, Antonio; Calabrò, Viola; Falco, Geppino; Keller, Simona; Lembo, Francesca; Avvedimento, Vittorio Enrico; Chiariotti, Lorenzo

    2016-01-01

    Bacterial lipopolysaccharide (LPS) induces release of inflammatory mediators both in immune and epithelial cells. We investigated whether changes of epigenetic marks, including selected histone modification and DNA methylation, may drive or accompany the activation of COX-2 gene in HT-29 human intestinal epithelial cells upon exposure to LPS. Here we describe cyclical histone acetylation (H3), methylation (H3K4, H3K9, H3K27) and DNA methylation changes occurring at COX-2 gene promoter overtime after LPS stimulation. Histone K27 methylation changes are carried out by the H3 demethylase JMJD3 and are essential for COX-2 induction by LPS. The changes of the histone code are associated with cyclical methylation signatures at the promoter and gene body of COX-2 gene. PMID:27253528

  10. Intestinal epithelial restitution. Involvement of specific laminin isoforms and integrin laminin receptors in wound closure of a transformed model epithelium

    DEFF Research Database (Denmark)

    Lotz, M M; Nusrat, A; Madara, J L;

    1997-01-01

    Disruptions in the mucosal lining of the gastrointestinal tract reseal by epithelial cell migration, a process termed restitution. We examined the involvement of laminin isoforms and their integrin receptors in restitution using the intestinal epithelial cell line T84. T84 cells express primarily...... laminins 5, 6, and 7 as indicated by immunostaining using laminin subunit-specific monoclonal antibodies (MAbs). A MAb (BM2) specific for the laminin alpha 3 subunit, a component of laminins 5, 6, and 7, completely inhibited the closure of mechanical wounds in T84 monolayers. Confocal microscopy using MAbs...... BM2 (laminin alpha 3 subunit) and 6F12 (laminin beta 3 subunit) revealed that laminin-5 is deposited in a basal matrix that extends into the wound. The MAbs 4E10 (laminin beta 1 subunit) and C4 (laminin beta 2 subunit) stained the lateral membranes between T84 cells. This staining was enhanced...

  11. Competitive inhibition of adherence of enterotoxigenic Escherichia coli,enteropathogenic Escherichia coli and Clostridium difficile to intestinal epithelial cell line Lovo by purified adhesin of Bifidobacterium adolescentis 1027

    Institute of Scientific and Technical Information of China (English)

    Shi-Shun Zhong; Zhen-Shu Zhang; Ji-De Wang; Zhuo-Sheng Lai; Qun-Ying Wang; Ling-Jia Pan; Yue-Xin Ren

    2004-01-01

    AIM: To observe competitive inhibition of adherence of enterotoxigenic Escherichia coli(ETEC), enteropathogenic Escherichia coli(EPEC) and Clostridium difficile ( C. difficile)to intestinal epithelial cell line Lovo by purified adhesin of Bifidobacterium adolescentis 1027 (B. ado 1027).METHODS: The binding of bacteria to intestinal epithelial cell line Lovo was counted by adhesion assay. The inhibition of adherence of ETEC, EPEC and C. difficile to intestinal epithelial cell line Lovo by purified adhesin of B. ado 1027was evaluated quantitatively by flow cytometry.RESULTS: The purified adhesin at the concentration of 10μg/mL, 20μg/mL and 30μg/mL except at 1μg/mL and 5μg/mL could inhibit significantly the adhesion of ETEC,EPEC and C. difficile to intestinal epithelial cell line Lovo.Moreover, we observed that a reduction in bacterial adhesion was occurred with increase in the concentration of adhesin,and MFI (Mean fluorescent intensity) was decreased with increase in the concentration of adhesin.CONCLUSION: The purified adhesin of B. ado 1027 can inhibit the adhesion of ETEC, EPEC and C. difficile to intestinal epithelial cell line Lovo in a dose-dependent manner.

  12. Calcium signals and calpain-dependent necrosis are essential for release of coxsackievirus B from polarized intestinal epithelial cells.

    Science.gov (United States)

    Bozym, Rebecca A; Patel, Kunal; White, Carl; Cheung, King-Ho; Bergelson, Jeffrey M; Morosky, Stefanie A; Coyne, Carolyn B

    2011-09-01

    Coxsackievirus B (CVB), a member of the enterovirus family, targets the polarized epithelial cells lining the intestinal tract early in infection. Although the polarized epithelium functions as a protective barrier, this barrier is likely exploited by CVB to promote viral entry and subsequent egress. Here we show that, in contrast to nonpolarized cells, CVB-infected polarized intestinal Caco-2 cells undergo nonapoptotic necrotic cell death triggered by inositol 1,4,5-trisphosphate receptor-dependent calcium release. We further show that CVB-induced cellular necrosis depends on the Ca(2+)-activated protease calpain-2 and that this protease is involved in CVB-induced disruption of the junctional complex and rearrangements of the actin cytoskeleton. Our study illustrates the cell signaling pathways hijacked by CVB, and perhaps other viral pathogens, to promote their replication and spread in polarized cell types.

  13. Murine Butyrophilin-like (Btnl 1 and Btnl6 form heteromeric complexes in small intestinal epithelial cells and promote proliferation of local T lymphocytes

    Directory of Open Access Journals (Sweden)

    Cristina eLebrero-Fernández

    2016-01-01

    Full Text Available To date, few molecular conduits mediating the cross-talk between intestinal epithelial cells and intraepithelial lymphocytes (IELs have been described. We recently showed that Butyrophilin-like (Btnl 1 can attenuate the epithelial response to activated IELs, resulting in reduced production of pro-inflammatory mediators such as IL-6 and CXCL1. We here report that like Btnl1, murine Btnl6 expression is primarily confined to the intestinal epithelium. Although Btnl1 can exist in a cell surface-expressed homomeric form, we found that it additionally forms heteromeric complexes with Btnl6, and that the engagement of Btnl1 is a prerequisite for surface expression of Btnl6 on intestinal epithelial cells. In an IEL-epithelial cell co-culture system, enforced epithelial cell expression of Btnl1 significantly enhanced the proliferation of IELs in the absence of exogenous activation. The effect on proliferation was dependent on the presence of IL-2 or IL-15 and restricted to IELs upregulating CD25. In the gamma delta (gd T-cell subset, the Btnl1-Btnl6 complex, but not Btnl1, specifically elevated the proliferation of IELs bearing the Vg7Vd4 receptor. Thus, our results show that murine epithelial cell-specific Btnl proteins can form intrafamily heterocomplexes, and suggest that the interaction between Btnl proteins and IELs regulates the expansion of IELs in the intestinal mucosa.

  14. A Lactobacillus rhamnosus GG-derived soluble protein, p40, stimulates ligand release from intestinal epithelial cells to transactivate epidermal growth factor receptor.

    Science.gov (United States)

    Yan, Fang; Liu, Liping; Dempsey, Peter J; Tsai, Yu-Hwai; Raines, Elaine W; Wilson, Carole L; Cao, Hailong; Cao, Zheng; Liu, LinShu; Polk, D Brent

    2013-10-18

    p40, a Lactobacillus rhamnosus GG (LGG)-derived soluble protein, ameliorates intestinal injury and colitis, reduces apoptosis, and preserves barrier function by transactivation of the EGF receptor (EGFR) in intestinal epithelial cells. The aim of this study is to determine the mechanisms by which p40 transactivates the EGFR in intestinal epithelial cells. Here we show that p40-conditioned medium activates EGFR in young adult mouse colon epithelial cells and human colonic epithelial cell line, T84 cells. p40 up-regulates a disintegrin and metalloproteinase domain-containing protein 17 (ADAM17) catalytic activity, and broad spectrum metalloproteinase inhibitors block EGFR transactivation by p40 in these two cell lines. In ADAM17-deficient mouse colonic epithelial (ADAM17(-/-) MCE) cells, p40 transactivation of EGFR is blocked, but can be rescued by re-expression with WT ADAM17. Furthermore, p40 stimulates release of heparin binding (HB)-EGF, but not transforming growth factor (TGF)α or amphiregulin, in young adult mouse colon cells and ADAM17(-/-) MCE cells overexpressing WT ADAM17. Knockdown of HB-EGF expression by siRNA suppresses p40 effects on transactivating EGFR and Akt, preventing apoptosis, and preserving tight junction function. The effects of p40 on HB-EGF release and ADAM17 activation in vivo are examined after administration of p40-containing pectin/zein hydrogel beads to mice. p40 stimulates ADAM17 activity and EGFR activation in colonic epithelial cells and increases HB-EGF levels in blood from WT mice, but not from mice with intestinal epithelial cell-specific ADAM17 deletion. Thus, these data define a mechanism of a probiotic-derived soluble protein in modulating intestinal epithelial cell homeostasis through ADAM17-mediated HB-EGF release, leading to transactivation of EGFR.

  15. Appropriate Crypt Formation in the Uterus for Embryo Homing and Implantation Requires Wnt5a-ROR Signaling

    Directory of Open Access Journals (Sweden)

    Jeeyeon Cha

    2014-07-01

    Full Text Available Embryo homing and implantation occur within a crypt (implantation chamber at the antimesometrial (AM pole along the uterus. The mechanism by which this is achieved is not known. Here, we show that villi-like epithelial projections from the main uterine lumen toward the AM pole at regularly spaced intervals that form crypts for embryo implantation were disrupted in mice with uterine loss or gain of function of Wnt5a, or loss of function of both Ror1 and Ror2. This disruption of Wnt5a-ROR signaling resulted in disorderly epithelial projections, crypt formation, embryo spacing, and impaired implantation. These early disturbances under abnormal Wnt5a-ROR signaling were reflected in adverse late pregnancy events, including defective decidualization and placentation, ultimately leading to compromised pregnancy outcomes. This study presents deeper insight regarding the formation of organized epithelial projections for crypt formation and embryo implantation for pregnancy success.

  16. Transcobalamin derived from bovine milk stimulates apical uptake of vitamin B12 into human intestinal epithelial cells.

    Science.gov (United States)

    Hine, Brad; Boggs, Irina; Green, Ralph; Miller, Joshua W; Hovey, Russell C; Humphrey, Rex; Wheeler, Thomas T

    2014-11-01

    Intestinal uptake of vitamin B12 (hereafter B12) is impaired in a significant proportion of the human population. This impairment is due to inherited or acquired defects in the expression or function of proteins involved in the binding of diet-derived B12 and its uptake into intestinal cells. Bovine milk is an abundant source of bioavailable B12 wherein it is complexed with transcobalamin. In humans, transcobalamin functions primarily as a circulatory protein, which binds B12 following its absorption and delivers it to peripheral tissues via its cognate receptor, CD320. In the current study, the transcobalamin-B12 complex was purified from cows' milk and its ability to stimulate uptake of B12 into cultured bovine, mouse and human cell lines was assessed. Bovine milk-derived transcobalamin-B12 complex was absorbed by all cell types tested, suggesting that the uptake mechanism is conserved across species. Furthermore, the complex stimulated the uptake of B12 via the apical surface of differentiated Caco-2 human intestinal epithelial cells. These findings suggest the presence of an alternative transcobalamin-mediated uptake pathway for B12 in the human intestine other than that mediated by the gastric glycoprotein, intrinsic factor. Our findings highlight the potential for transcobalamin-B12 complex derived from bovine milk to be used as a natural bioavailable alternative to orally administered free B12 to overcome B12 malabsorption.

  17. Porcine intestinal epithelial cell lines as a new in vitro model for studying adherence and pathogenesis of enterotoxigenic Escherichia coli.

    Science.gov (United States)

    Koh, Seung Y; George, Sajan; Brözel, Volker; Moxley, Rodney; Francis, David; Kaushik, Radhey S

    2008-07-27

    Enterotoxigenic Escherichia coli (ETEC) infections result in large economic losses in the swine industry worldwide. The organism causes diarrhea by adhering to and colonizing enterocytes in the small intestines. While much progress has been made in understanding the pathogenesis of ETEC, no homologous intestinal epithelial cultures suitable for studying porcine ETEC pathogenesis have been described prior to this report. In the current study, we investigated the adherence of various porcine ETEC strains to two porcine (IPEC-1 and IPEC-J2) and one human (INT-407) small intestinal epithelial cell lines. Each cell line was assessed for its ability to support the adherence of E. coli expressing fimbrial adhesins K88ab, K88ac, K88ad, K99, F41, 987P, and F18. Wild-type ETEC expressing K88ab, K88ac, and K88ad efficiently bound to both IPEC-1 and IPEC-J2 cells. An ETEC strain expressing both K99 and F41 bound heavily to both porcine cell lines but an E. coli strain expressing only K99 bound very poorly to these cells. E. coli expressing F18 adhesin strongly bound to IPEC-1 cells but did not adhere to IPEC-J2 cells. The E. coli strains G58-1 and 711 which express no fimbrial adhesins and those that express 987P fimbriae failed to bind to either porcine cell line. Only strains B41 and K12:K99 bound in abundance to INT-407 cells. The binding of porcine ETEC to IPEC-J2, IPEC-1 and INT-407 with varying affinities, together with lack of binding of 987P ETEC and non-fimbriated E. coli strains, suggests strain-specific E. coli binding to these cell lines. These findings suggest the potential usefulness of porcine intestinal cell lines for studying ETEC pathogenesis.

  18. Cyanidin-3-O-Glucoside Modulates the In Vitro Inflammatory Crosstalk between Intestinal Epithelial and Endothelial Cells

    Directory of Open Access Journals (Sweden)

    Daniela Ferrari

    2017-01-01

    Full Text Available Intestinal epithelium represents a protective physical barrier and actively contributes to the mucosal immune system. Polarized basolateral intestinal secretion of inflammatory mediators, followed by activation of NF-κB signaling and inflammatory pathways in endothelial cells, efficiently triggers extravasation of neutrophils from the vasculature, therefore contributing to the development and maintenance of intestinal inflammation. Proper regulation of NF-κB activation at the epithelial interface is crucial for the maintenance of physiological tissue homeostasis. Many papers reported that anthocyanins, a group of compounds belonging to flavonoids, possess anti-inflammatory effects and modulate NF-κB activity. In this study, by using a coculture in vitro system, we aimed to evaluate the effects of TNF-α-stimulated intestinal cells on endothelial cells activation, as well as the protective effects of cyanidin-3-glucoside (C3G. In this model, TNF-α induced nuclear translocation of NF-κB and TNF-α and IL-8 gene expression in Caco-2 cells, whereas C3G pretreatment dose-dependently reduced these effects. Furthermore, TNF-α-stimulated Caco-2 cells induced endothelial cells activation with increased E-selectin and VCAM-1 mRNA, leukocyte adhesion, and NF-κB levels in HUVECs, which were inhibited by C3G. We demonstrated that selective inhibition of the NF-κB pathway in epithelial cells represents the main mechanism by which C3G exerts these protective effects. Thus, anthocyanins could contribute to the management of chronic gut inflammatory diseases.

  19. Intestine.

    Science.gov (United States)

    Smith, J M; Skeans, M A; Horslen, S P; Edwards, E B; Harper, A M; Snyder, J J; Israni, A K; Kasiske, B L

    2016-01-01

    Intestine and intestine-liver transplant plays an important role in the treatment of intestinal failure, despite decreased morbidity associated with parenteral nutrition. In 2014, 210 new patients were added to the intestine transplant waiting list. Among prevalent patients on the list at the end of 2014, 65% were waiting for an intestine transplant and 35% were waiting for an intestine-liver transplant. The pretransplant mortality rate decreased dramatically over time for all age groups. Pretransplant mortality was highest for adult candidates, at 22.1 per 100 waitlist years compared with less than 3 per 100 waitlist years for pediatric candidates, and notably higher for candidates for intestine-liver transplant than for candidates for intestine transplant without a liver. Numbers of intestine transplants without a liver increased from a low of 51 in 2013 to 67 in 2014. Intestine-liver transplants increased from a low of 44 in 2012 to 72 in 2014. Short-gut syndrome (congenital and other) was the main cause of disease leading to both intestine and intestine-liver transplant. Graft survival improved over the past decade. Patient survival was lowest for adult intestine-liver recipients and highest for pediatric intestine recipients.

  20. A key role for E-cadherin in intestinal homeostasis and Paneth cell maturation.

    Science.gov (United States)

    Schneider, Marlon R; Dahlhoff, Maik; Horst, David; Hirschi, Benjamin; Trülzsch, Konrad; Müller-Höcker, Josef; Vogelmann, Roger; Allgäuer, Michael; Gerhard, Markus; Steininger, Sylvia; Wolf, Eckhard; Kolligs, Frank T

    2010-12-14

    E-cadherin is a major component of adherens junctions. Impaired expression of E-cadherin in the small intestine and colon has been linked to a disturbed intestinal homeostasis and barrier function. Down-regulation of E-cadherin is associated with the pathogenesis of infections with enteropathogenic bacteria and Crohn's disease. To genetically clarify the function of E-cadherin in intestinal homeostasis and maintenance of the epithelial defense line, the Cdh1 gene was conditionally inactivated in the mouse intestinal epithelium. Inactivation of the Cdh1 gene in the small intestine and colon resulted in bloody diarrhea associated with enhanced apoptosis and cell shedding, causing life-threatening disease within 6 days. Loss of E-cadherin led cells migrate faster along the crypt-villus axis and perturbed cellular differentiation. Maturation and positioning of goblet cells and Paneth cells, the main cell lineage of the intestinal innate immune system, was severely disturbed. The expression of anti-bacterial cryptidins was reduced and mice showed a deficiency in clearing enteropathogenic bacteria from the intestinal lumen. These results highlight the central function of E-cadherin in the maintenance of two components of the intestinal epithelial defense: E-cadherin is required for the proper function of the intestinal epithelial lining by providing mechanical integrity and is a prerequisite for the proper maturation of Paneth and goblet cells.

  1. A key role for E-cadherin in intestinal homeostasis and Paneth cell maturation.

    Directory of Open Access Journals (Sweden)

    Marlon R Schneider

    Full Text Available BACKGROUND: E-cadherin is a major component of adherens junctions. Impaired expression of E-cadherin in the small intestine and colon has been linked to a disturbed intestinal homeostasis and barrier function. Down-regulation of E-cadherin is associated with the pathogenesis of infections with enteropathogenic bacteria and Crohn's disease. METHODS AND FINDINGS: To genetically clarify the function of E-cadherin in intestinal homeostasis and maintenance of the epithelial defense line, the Cdh1 gene was conditionally inactivated in the mouse intestinal epithelium. Inactivation of the Cdh1 gene in the small intestine and colon resulted in bloody diarrhea associated with enhanced apoptosis and cell shedding, causing life-threatening disease within 6 days. Loss of E-cadherin led cells migrate faster along the crypt-villus axis and perturbed cellular differentiation. Maturation and positioning of goblet cells and Paneth cells, the main cell lineage of the intestinal innate immune system, was severely disturbed. The expression of anti-bacterial cryptidins was reduced and mice showed a deficiency in clearing enteropathogenic bacteria from the intestinal lumen. CONCLUSION: These results highlight the central function of E-cadherin in the maintenance of two components of the intestinal epithelial defense: E-cadherin is required for the proper function of the intestinal epithelial lining by providing mechanical integrity and is a prerequisite for the proper maturation of Paneth and goblet cells.

  2. Intestinal Epithelial Cell Regulation of Adaptive Immune Dysfunction in Human Type 1 Diabetes

    Science.gov (United States)

    Graves, Christina L.; Li, Jian; LaPato, Melissa; Shapiro, Melanie R.; Glover, Sarah C.; Wallet, Mark A.; Wallet, Shannon M.

    2017-01-01

    Environmental factors contribute to the initiation, progression, and maintenance of type 1 diabetes (T1D), although a single environmental trigger for disease has not been identified. Studies have documented the contribution of immunity within the gastrointestinal tract (GI) to the expression of autoimmunity at distal sites. Intestinal epithelial cells (IECs) regulate local and systemic immunologic homeostasis through physical and biochemical interactions with innate and adaptive immune populations. We hypothesize that a loss in the tolerance-inducing nature of the GI tract occurs within T1D and is due to altered IECs’ innate immune function. As a first step in addressing this hypothesis, we contrasted the global immune microenvironment within the GI tract of individuals with T1D as well as evaluated the IEC-specific effects on adaptive immune cell phenotypes. The soluble and cellular immune microenvironment within the duodenum, the soluble mediator profile of primary IECs derived from the same duodenal tissues, and the effect of the primary IECs’ soluble mediator profile on T-cell expansion and polarization were evaluated. Higher levels of IL-17C and beta-defensin 2 (BD-2) mRNA in the T1D-duodenum were observed. Higher frequencies of type 1 innate lymphoid cells (ILC1) and CD8+CXCR3+ T-cells (Tc1) were also observed in T1D-duodenal tissues, concomitant with lower frequencies of type 3 ILC (ILC3) and CD8+CCR6+ T-cells (Tc17). Higher levels of proinflammatory mediators (IL-17C and BD-2) in the absence of similar changes in mediators associated with homeostasis (interleukin 10 and thymic stromal lymphopoietin) were also observed in T1D-derived primary IEC cultures. T1D-derived IEC culture supernatants induced more robust CD8+ T-cell proliferation along with enhanced polarization of Tc1 populations, at the expense of Tc17 polarization, as well as the expansion of CXCR3+CCR6+/− Tregs, indicative of a Th1-like and less regulatory phenotype. These data demonstrate

  3. Metformin Improves Ileal Epithelial Barrier Function in Interleukin-10 Deficient Mice.

    Science.gov (United States)

    Xue, Yansong; Zhang, Hanying; Sun, Xiaofei; Zhu, Mei-Jun

    2016-01-01

    The impairment of intestinal epithelial barrier is the main etiologic factor of inflammatory bowel disease. The proper intestinal epithelial proliferation and differentiation is crucial for maintaining intestinal integrity. Metformin is a common anti-diabetic drug. The objective is to evaluate the protective effects of metformin on ileal epithelial barrier integrity using interleukin-10 deficient (IL10KO) mice. Wild-type and IL10KO mice were fed with/without metformin for 6 weeks and then ileum was collected for analyses. The mediatory role of AMP-activated protein kinase (AMPK) was further examined by gain and loss of function study in vitro. Compared to wild-type mice, IL10KO mice had increased proliferation, reduced goblet cell and Paneth cell lineage differentiation in the ileum tissue, which was accompanied with increased crypt expansion. Metformin supplementation mitigated intestinal cell proliferation, restored villus/crypt ratio, increased goblet cell and Paneth cell differentiation and improved barrier function. In addition, metformin supplementation in IL10KO mice suppressed macrophage pro-inflammatory activity as indicated by reduced M1 macrophage abundance and decreased pro-inflammatory cytokine IL-1β, TNF-α and IFN-γ expressions. As a target of metformin, AMPK phosphorylation was enhanced in mice treated with metformin, regardless of mouse genotypes. In correlation, the mRNA level of differentiation regulator including bmp4, bmpr2 and math1 were also increased in IL10KO mice supplemented with metformin, which likely explains the enhanced epithelial differentiation in IL10KO mice with metformin. Consistently, in Caco-2 cells, metformin promoted claudin-3 and E-cadherin assembly and mitigated TNF-α-induced fragmentation of tight junction proteins. Gain and loss of function assay also demonstrated AMPK was correlated with epithelial differentiation and proliferation. Metformin supplementation promotes secretory cell lineage differentiation, suppresses

  4. Establishment of pharmacological experimental methods of rat small intestinal crypt cell line%小肠隐窝细胞株药理实验方法的建立

    Institute of Scientific and Technical Information of China (English)

    张子理; 岳双冰; 田欢; 莫婷; 林洪; 张广路; 陈蔚文

    2014-01-01

    目的:建立小肠隐窝细胞株(IEC-6)药理实验方法。方法:观察细胞接种密度、α-二氟甲基鸟氨酸(DFMO)和胃泌素对IEC-6细胞增殖及细胞鸟氨酸脱羧酶(ODC)的影响。结果:较高接种密度(>0.5×104细胞/孔)组,接种后第2天,细胞生长抑制,尤其是密度增加到4×104细胞/孔时,第2~3天,OD值逐渐增加,第4天明显增加,第5天达高峰,此后OD值开始下降。而低密度(0.2×104细胞/孔)接种后第4天,细胞生长出现抑制,此后其生长与其他密度相似。加入DFMO后1~3天,完全抑制了细胞增殖,此后与空白组一样,细胞逐渐生长。 DFMO还明显抑制IEC-6细胞分化和移行,以及 ODC活性和腐胺含量,与空白组比较具有显著性差异(P<0.01)。IEC-6细胞在胃泌素250μg·L-1作用后第一天,开始增殖,第3天达高峰。胃泌素500μg·L-1作用后第1~2天,细胞开始增殖,第3天以后,细胞增殖下降。胃泌素明显促进细胞分化和移行。与空白组比较,胃泌素250μg·L-1分别使ODC mRNA水平,ODC活性,腐胺含量增加1.09倍(P<0.05),1.71倍(P<0.01)和5.30倍(P<0.01)。同样,胃泌素500μg·L-1可使以上3项指标分别升高1.16倍(P<0.05),1.63倍(P<0.05)和4.41倍(P<0.01)。但胃泌素两个剂量组之间无显著性差异。结论:IEC-6细胞是进行胃肠粘膜修复药理实验的合适细胞模型。%Objective:To established a pharmacological experimental methods of rat small intestinal crypt cell line.Methods:To observed the role of plating densities,alpha-difluoromethylornithine(DFMO)and pentagastrin on the proliferation,differentiation,migration , ODC mRNA level,ODC activity and putrescine content of IEC-6 cells in vitro. Results:Higher plating densities (>0.5×104 cells/well) inhibited the growth of cells on day 2 , especially when a density reach to 4 × 104 cells/well , the OD

  5. Lipoteichoic Acid of Probiotic Lactobacillus plantarum Attenuates Poly I:C-Induced IL-8 Production in Porcine Intestinal Epithelial Cells

    Directory of Open Access Journals (Sweden)

    Kyoung Whun Kim

    2017-09-01

    Full Text Available Probiotics in livestock feed supplements are considered a replacement for antibiotics that enhance gastrointestinal immunity. Although bacterial cell wall components have been proposed to be associated with probiotic function, little evidence demonstrates that they are responsible for probiotic functions in livestock. The present study demonstrated that lipoteichoic acid (LTA of Lactobacillus plantarum (Lp.LTA confers anti-inflammatory responses in porcine intestinal epithelial cell line, IPEC-J2. A synthetic analog of viral double-stranded RNA, poly I:C, dose-dependently induced IL-8 production at the mRNA and protein levels in IPEC-J2 cells. Lp.LTA, but not lipoprotein or peptidoglycan from L. plantarum, exclusively suppressed poly I:C-induced IL-8 production. Compared with LTAs from other probiotic Lactobacillus strains including L. delbrueckii, L. sakei, and L. rhamnosus GG, Lp.LTA had higher potential to suppress poly I:C-induced IL-8 production. Dealanylated or deacylated Lp.LTA did not suppress poly I:C-induced IL-8 production, suggesting that D-alanine and lipid moieties in the Lp.LTA structure were responsible for the inhibition. Furthermore, Lp.LTA attenuated the phosphorylation of ERK and p38 kinase as well as the activation of NF-κB, resulting in decreased IL-8 production. Taken together, these results suggest that Lp.LTA acts as an effector molecule to inhibit viral pathogen-induced inflammatory responses in porcine intestinal epithelial cells.

  6. Binding of the hop (Humulus lupulus L.) chalcone xanthohumol to cytosolic proteins in Caco-2 intestinal epithelial cells.

    Science.gov (United States)

    Pang, Yan; Nikolic, Dejan; Zhu, Dongwei; Chadwick, Lucas R; Pauli, Guido F; Farnsworth, Norman R; van Breemen, Richard B

    2007-07-01

    Used in the brewing of beer, hops (Humulus lupulus L.) contain the prenylated chalcone xanthohumol, which is under investigation as a cancer chemoprevention agent and as a precursor for the estrogenic flavanones isoxanthohumol and 8-prenylnaringenin. The uptake, transport and accumulation of xanthohumol were studied using the human intestinal epithelial cell line Caco-2 to help understand the poor bioavailability of this chalcone. Studies were carried out using Caco-2 cell monolayers 18-21 days after seeding. The apparent K(m) and V(max) values of xanthohumol accumulation in Caco-2 cells were determined, and the protein binding of xanthohumol in sub-cellular fractions of Caco-2 cells was investigated. Approximately 70% of xanthohumol added to the apical side of Caco-2 cells accumulated inside the cells, while 93% of the intracellular xanthohumol was localized in the cytosol. Xanthohumol accumulation was temperature dependent and saturable with an apparent K(m )value of 26.5 +/- 4.66 muM and an apparent V(max) of 0.215 +/- 0.018 nmol/mg protein/min. Facilitated transport was not responsible for the uptake of xanthohumol, instead, accumulation inside the Caco-2 cells was apparently the result of specific binding to cytosolic proteins. These data suggest that specific binding of xanthohumol to cytosolic proteins in intestinal epithelial cells contributes to the poor oral bioavailability observed previously in vivo.

  7. Receptor-like Molecules on Human Intestinal Epithelial Cells Interact with an Adhesion Factor from Lactobacillus reuteri.

    Science.gov (United States)

    Matsuo, Yosuke; Miyoshi, Yukihiro; Okada, Sanae; Satoh, Eiichi

    2012-01-01

    A surface protein of Lactobacillus reuteri, mucus adhesion-promoting protein (MapA), is considered to be an adhesion factor. MapA is expressed in L. reuteri strains and adheres to piglet gastric mucus, collagen type I, and human intestinal epithelial cells such as Caco-2. The aim of this study was to identify molecules that mediate the attachment of MapA from L. reuteri to the intestinal epithelial cell surface by investigating the adhesion of MapA to receptor-like molecules on Caco-2 cells. MapA-binding receptor-like molecules were detected in Caco-2 cell lysates by 2D-PAGE. Two proteins, annexin A13 (ANXA13) and paralemmin (PALM), were identified by MALDI TOF-MS. The results of a pull-down assay showed that MapA bound directly to ANXA13 and PALM. Fluorescence microscopy studies confirmed that MapA binding to ANXA13 and PALM was colocalized on the Caco-2 cell membrane. To evaluate whether ANXA13 and PALM are important for MapA adhesion, ANXA13 and PALM knockdown cell lines were established. The adhesion of MapA to the abovementioned cell lines was reduced compared with that to wild-type Caco-2 cells. These knockdown experiments established the importance of these receptor-like molecules in MapA adhesion.

  8. Transmissible Plasmid Containing Salmonella enterica Heidelberg Isolates Modulate Cytokine Production During Early Stage of Interaction with Intestinal Epithelial Cells.

    Science.gov (United States)

    Gokulan, Kuppan; Khare, Sangeeta; Williams, Katherine; Foley, Steven L

    2016-08-01

    The variation in cytokine production during bacterial invasion of human intestinal epithelial cells (IECs) is a contributing factor for progression of the infection. A few Salmonella enterica Heidelberg strains isolated from poultry products harbor transmissible plasmids (TPs), including those that encode a type-IV secretion system. Earlier, we showed that these TPs are responsible for increased virulence during infection. This study examines the potential role of these TPs in cytokine production in IECs. This study showed that S. Heidelberg strains containing TPs (we refer as virulent strains) caused decreased interleukin (IL)-10 production in IECs after 1 h infection. The virulent strains induced a high level of tumor necrosis factor-α production under identical conditions. The virulent strains of S. Heidelberg also altered the production of IL-2, IL-17, and granulocyte macrophage colony-stimulating factor compared to an avirulent strain. As a part of infection, bacteria cross the epithelial barrier and encounter intestinal macrophages. Hence, we examined the cytotoxic mechanism of strains of S. Heidelberg in macrophages. Scanning electron microscopy showed cell necrosis occurs during the early stage of infection. In conclusion, virulent S. Heidelberg strains were able to modify the host cytokine profile during the early stages of infection and also caused necrosis in macrophages.

  9. Use of Fluorescence Quantitative Polymerase Chain Reaction (PCR) for the Detection of Escherichia coli Adhesion to Pig Intestinal Epithelial Cells.

    Science.gov (United States)

    Dai, C H; Gan, L N; Qin, W U; Zi, C; Zhu, G Q; Wu, S L; Bao, W B

    2016-09-01

    An efficient and accurate method to test Escherichia coli (E. coli) adhesion to intestinal epithelial cells will contribute to the study of bacterial pathogenesis and the function of genes that encode receptors related to adhesion. This study used the quantitative real-time polymerase chain reaction (qPCR) method. qPCR primers were designed from the PILIN gene of E. coli F18ab, F18ac, and K88ac, and the pig β-ACTIN gene. Total deoxyribonucleic acid (DNA) from E. coli and intestinal epithelial cells (IPEC-J2 cells) were used as templates for qPCR. The 2-ΔΔCt formula was used to calculate the relative number of bacteria in cultures of different areas. We found that the relative numbers of F18ab, F18ac, and K88ac that adhered to IPEC-J2 cells did not differ significantly in 6-, 12-, and 24-well culture plates. This finding indicated that there was no relationship between the relative adhesion number of E. coli and the area of cells, so the method of qPCR could accurately test the relative number of E. coli. This study provided a convenient and reliable testing method for experiments involving E. coli adhesion, and also provided innovative ideas for similar detection methods.

  10. New insights into mycotoxin mixtures: the toxicity of low doses of Type B trichothecenes on intestinal epithelial cells is synergistic.

    Science.gov (United States)

    Alassane-Kpembi, Imourana; Kolf-Clauw, Martine; Gauthier, Thierry; Abrami, Roberta; Abiola, François A; Oswald, Isabelle P; Puel, Olivier

    2013-10-01

    Deoxynivalenol (DON) is the most prevalent trichothecene mycotoxin in crops in Europe and North America. DON is often present with other type B trichothecenes such as 3-acetyldeoxynivalenol (3-ADON), 15-acetyldeoxynivalenol (15-ADON), nivalenol (NIV) and fusarenon-X (FX). Although the cytotoxicity of individual mycotoxins has been widely studied, data on the toxicity of mycotoxin mixtures are limited. The aim of this study was to assess interactions caused by co-exposure to Type B trichothecenes on intestinal epithelial cells. Proliferating Caco-2 cells were exposed to increasing doses of Type B trichothecenes, alone or in binary or ternary mixtures. The MTT test and neutral red uptake, respectively linked to mitochondrial and lysosomal functions, were used to measure intestinal epithelial cytotoxicity. The five tested mycotoxins had a dose-dependent effect on proliferating enterocytes and could be classified in increasing order of toxicity: 3-ADONmycotoxin combinations were synergistic; however DON-NIV-FX mixture showed antagonism. At higher concentrations (cytotoxic effect around 50%), the combinations had an additive or nearly additive effect. These results indicate that the simultaneous presence of low doses of mycotoxins in food commodities and diet may be more toxic than predicted from the mycotoxins alone. Considering the frequent co-occurrence of trichothecenes in the diet and the concentrations of toxins to which consumers are exposed, this synergy should be taken into account.

  11. Kefir-isolated bacteria and yeasts inhibit Shigella flexneri invasion and modulate pro-inflammatory response on intestinal epithelial cells.

    Science.gov (United States)

    Bolla, P A; Abraham, A G; Pérez, P F; de Los Angeles Serradell, M

    2016-02-01

    The aim of this work was to evaluate the ability of a kefir-isolated microbial mixture containing three bacterial and two yeast strains (MM) to protect intestinal epithelial cells against Shigella flexneri invasion, as well as to analyse the effect on pro-inflammatory response elicited by this pathogen. A significant decrease in S. flexneri strain 72 invasion was observed on both HT-29 and Caco-2 cells pre-incubated with MM. Pre-incubation with the individual strains Saccharomyces cerevisiae CIDCA 8112 or Lactococcus lactis subsp. lactis CIDCA 8221 also reduced the internalisation of S. flexneri into HT-29 cells although in a lesser extent than MM. Interestingly, Lactobacillus plantarum CIDCA 83114 exerted a protective effect on the invasion of Caco-2 and HT-29 cells by S. flexneri. Regarding the pro-inflammatory response on HT-29 cells, S. flexneri infection induced a significant activation of the expression of interleukin 8 (IL-8), chemokine (C-C motif) ligand 20 (CCL20) and tumour necrosis factor alpha (TNF-α) encoding genes (Pkefir, resulted in inhibition of S. flexneri internalisation into human intestinal epithelial cells, along with the inhibition of the signalling via NF-κB that in turn led to the attenuation of the inflammatory response.

  12. Assessment of cytotoxicity exerted by leaf extracts from plants of the genus Rhododendron towards epidermal keratinocytes and intestine epithelial cells.

    Science.gov (United States)

    Rezk, Ahmed; Al-Hashimi, Alaa; John, Warren; Schepker, Hartwig; Ullrich, Matthias S; Brix, Klaudia

    2015-10-15

    Rhododendron leaf extracts were previously found to exert antimicrobial activities against a range of Gram-positive bacteria. In this study, we investigated which of the extracts with these antimicrobial properties would be best suited for further exploitation. Specifically, the project aims to identify biologically active compounds that affect bacterial but not mammalian cells when applied in medical treatments such as lotions for ectopic application onto skin, or as orally administered drugs. Different concentrations of DMSO-dissolved remnants of crude methanol Rhododendron leaf extracts were incubated for 24 h with cultured epidermal keratinocytes (human HaCaT cell line) and epithelial cells of the intestinal mucosa (rat IEC6 cell line) and tested for their cytotoxic potential. In particular, the cytotoxic potencies of the compounds contained in antimicrobial Rhododendron leaf extracts were assessed by quantifying their effects on (i) plasma membrane integrity, (ii) cell viability and proliferation rates, (iii) cellular metabolism, (iv) cytoskeletal architecture, and (v) determining initiation of cell death pathways by morphological and biochemical means. Extracts of almost all Rhododendron species, when applied at 500 μg/mL, were potent in negatively affecting both keratinocytes and intestine epithelial cells, except material from R. hippophaeoides var. hippophaeoides. Extracts of R. minus and R. racemosum were non-toxic towards both mammalian cell types when used at 50 μg/mL, which was equivalent to their minimal inhibitory concentration against bacteria. At this concentration, leaf extracts from three other highly potent antimicrobial Rhododendron species proved non-cytotoxic against one or the other mammalian cell type: Extracts of R. ferrugineum were non-toxic towards IEC6 cells, and extracts of R. rubiginosum as well as R. concinnum did not affect HaCaT cells. In general, keratinocytes proved more resistant than intestine epithelial cells against the

  13. Protective effects of ψ taraxasterol 3-O-myristate and arnidiol 3-O-myristate isolated from Calendula officinalis on epithelial intestinal barrier.

    Science.gov (United States)

    Dall'Acqua, Stefano; Catanzaro, Daniela; Cocetta, Veronica; Igl, Nadine; Ragazzi, Eugenio; Giron, Maria Cecilia; Cecconello, Laura; Montopoli, Monica

    2016-03-01

    The triterpene esters ᴪ taraxasterol-3-O-myristate (1) and arnidiol-3-O-myristate (2) were tested for their ability to protect epithelial intestinal barrier in an in vitro model. Their effects on ROS production and on trans-epithelial resistance were investigated on CaCo-2 cell monolayers both in basal and stress-induced conditions. Both compounds were able to modulate the stress damage induced by H2O2 and INFγ+TNFα, showing a potential use as model compounds for the study of new therapeutic agents for intestinal inflammations.

  14. Lactobacillus rhamnosus CNCMI-4317 Modulates Fiaf/Angptl4 in Intestinal Epithelial Cells and Circulating Level in Mice.

    Science.gov (United States)

    Jacouton, Elsa; Mach, Núria; Cadiou, Julie; Lapaque, Nicolas; Clément, Karine; Doré, Joël; van Hylckama Vlieg, Johan E T; Smokvina, Tamara; Blottière, Hervé M

    2015-01-01

    Identification of new targets for metabolic diseases treatment or prevention is required. In this context, FIAF/ANGPTL4 appears as a crucial regulator of energy homeostasis. Lactobacilli are often considered to display beneficial effect for their hosts, acting on different regulatory pathways. The aim of the present work was to study the effect of several lactobacilli strains on Fiaf gene expression in human intestinal epithelial cells (IECs) and on mice tissues to decipher the underlying mechanisms. Nineteen lactobacilli strains have been tested on HT-29 human intestinal epithelial cells for their ability to regulate Fiaf gene expression by RT-qPCR. In order to determine regulated pathways, we analysed the whole genome transcriptome of IECs. We then validated in vivo bacterial effects using C57BL/6 mono-colonized mice fed with normal chow. We identified one strain (Lactobacillus rhamnosus CNCMI-4317) that modulated Fiaf expression in IECs. This regulation relied potentially on bacterial surface-exposed molecules and seemed to be PPAR-γ independent but PPAR-α dependent. Transcriptome functional analysis revealed that multiple pathways including cellular function and maintenance, lymphoid tissue structure and development, as well as lipid metabolism were regulated by this strain. The regulation of immune system and lipid and carbohydrate metabolism was also confirmed by overrepresentation of Gene Ontology terms analysis. In vivo, circulating FIAF protein was increased by the strain but this phenomenon was not correlated with modulation Fiaf expression in tissues (except a trend in distal small intestine). We showed that Lactobacillus rhamnosus CNCMI-4317 induced Fiaf expression in human IECs, and increased circulating FIAF protein level in mice. Moreover, this effect was accompanied by transcriptome modulation of several pathways including immune response and metabolism in vitro.

  15. AT1R blocker losartan attenuates intestinal epithelial cell apoptosis in a mouse model of Crohn's disease.

    Science.gov (United States)

    Liu, Tian-Jing; Shi, Yong-Yan; Wang, En-Bo; Zhu, Tong; Zhao, Qun

    2016-02-01

    Angiotensin II, which is the main effector of the renin‑angiotensin system, has an important role in intestinal inflammation via the angiotensin II type 1 receptor (AT1R). The present study aimed to investigate the protective effects of the AT1R blocker losartan on 2,4,6-trinitrobenzenesulphonic acid (TNBS)-induced colitis. Losartan was administered to male adult C57BL/6 J mice 2 weeks prior to the induction of colitis, and images of the whole colon were captured to record changes, scored according to a microscopic scoring system, and reverse transcription-quantitative polymerase chain reaction were performed in order to investigate colonic inflammation. In addition, intestinal epithelial barrier permeability was evaluated, and intestinal epithelial cell (IEC) apoptosis was measured using terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining, and apoptosis-related protein expression levels were detected by western blotting. Losartan was able to attenuate TNBS-induced body weight loss and colonic damage. Furthermore, T helper 1-mediated proinflammatory cytokines were suppressed by losartan, and gut permeability was largely preserved. TUNEL staining revealed reduced IEC apoptosis in the losartan-treated mice. Losartan also increased the B-cell lymphoma 2 (Bcl2)/Bcl-2-associated X protein (Bax) ratio and suppressed caspase-3 induction. These results suggested that the AT1R blocker losartan may attenuate TNBS-induced colitis by inhibiting the apoptosis of IECs. The effects of losartan were partially mediated through increasing the Bcl-2/Bax ratio and subsequently suppressing the induction of the proapoptotic mediator caspase-3.

  16. Thymosin beta-4 knockdown in IEC-6 normal intestinal epithelial cells induces DNA re-replication via downregulating Emi1.

    Science.gov (United States)

    Chao, Ta-Chung; Chen, Ke-Jay; Tang, Mei-Chuan; Chan, Li-Chuan; Chen, Po-Min; Tzeng, Cheng-Hwai; Su, Yeu

    2014-11-01

    Thymosin β4 (Tβ4 ) is a multifunctional protein already used clinically to treat various diseases; however, the promoting effect of this protein on tumor malignancy should not be neglected. Here, we assessed whether Tβ4 alteration influences normal intestinal epithelial cells because Tβ4 is deemed a novel target for treating colorectal cancer (CRC). For this purpose, we examined the consequences of shRNA-mediated knockdown of Tβ4 in IEC-6 normal rat small intestinal cells and found that inhibiting Tβ4 expression significantly suppressed their growth and induced apoptosis in some cells. Flow cytometric analysis further revealed a marked decrease of G0/G1 population but a drastic increase of polyploid ones in these cells. The increase of polyploidy likely resulted from DNA re-replication because not only the de novo DNA synthesis was greatly increased but also the expression levels of Cdc6 (a replication-licensing factor), cyclin A, and phosphorylated-checkpoint kinase 1 were all dramatically elevated. Moreover, marked reductions in both RNA and protein levels of Emi1 (early mitotic inhibitor 1) were also detected in Tβ4 -downregulated IEC-6 cells which might be accounted by the downregulation of E2F1, a transcription factor capable of inducing Emi1 expression, mediated by glycogen synthase-3β (GSK-3β). To our best knowledge, this is the first report showing that inhibiting Tβ4 expression triggers DNA re-replication in normal intestinal epithelial cells, suggesting that this G-actin sequester may play a crucial role in maintaining genome stability in these cells. More importantly, clinical oncologists should take this novel activity into consideration when design CRC therapy based on targeting Tβ4 . © 2014 Wiley Periodicals, Inc.

  17. Membrane receptor-initiated signaling in 1,25(OH)2D3-stimulated calcium uptake in intestinal epithelial cells.

    Science.gov (United States)

    Khanal, Ramesh C; Peters, Tremaine M Sterling; Smith, Nathan M; Nemere, Ilka

    2008-11-01

    Demonstrating 1,25(OH)2D3-stimulated calcium uptake in isolated chick intestinal epithelial cells has been complicated by simultaneous enhancement of both uptake and efflux. We now report that in intestinal cells of adult birds, or those of young birds cultured for 72 h, 1,25(OH)2D3-stimulates 45Ca uptake to greater than 140% of corresponding controls within 3 min of addition. Such cells have lost hormone-stimulated protein kinase C (PKC) activity, believed to mediate calcium efflux. To further test this hypothesis, freshly isolated cells were preincubated with calphostin C, and calcium uptake monitored in the presence or absence of steroid. Only cells treated with the PKC inhibitor demonstrated a significant increase in 45Ca uptake in response to 1,25(OH)2D3, relative to corresponding controls. In addition, phorbol ester was shown to stimulate efflux, while forskolin stimulated uptake. To further investigate the mechanisms involved in calcium uptake, we assessed the role of TRPV6 and its activation by beta-glucuronidase. beta-Glucuronidase secretion from isolated intestinal epithelial cells was significantly increased by treatment with 1,25(OH)2D3, PTH, or forskolin, but not by phorbol ester. Treatment of cells with beta-glucuronidase, in turn, stimulated 45Ca uptake. Finally, transfection of cells with siRNA to either beta-glucuronidase or TRPV6 abolished 1,25(OH)2D3-enhanced calcium uptake relative to controls transfected with scrambled siRNA. Confocal microscopy further indicated rapid redistribution of enzyme and calcium channel after steroid. 1,25(OH)2D3 and PTH increase calcium uptake by stimulating the PKA pathway to release beta-glucuronidase, which in turn activates TRPV6. 1,25(OH)2D3-enhanced calcium efflux is mediated by the PKC pathway.

  18. The Bacterial Species Campylobacter jejuni Induce Diverse Innate Immune Responses in Human and Avian Intestinal Epithelial Cells

    Directory of Open Access Journals (Sweden)

    Daniel A. John

    2017-09-01

    Full Text Available Campylobacter remain the major cause of human gastroenteritis in the Developed World causing a significant burden to health services. Campylobacter are pathogens in humans and chickens, although differences in mechanistic understanding are incomplete, in part because phenotypic strain diversity creates inconsistent findings. Here, we took Campylobacter jejuni isolates (n = 100 from multi-locus sequence typed collections to assess their pathogenic diversity, through their inflammatory, cytotoxicity, adhesion, invasion and signaling responses in a high-throughput model using avian and human intestinal epithelial cells. C. jejuni induced IL-8 and CXCLi1/2 in human and avian epithelial cells, respectively, in a MAP kinase-dependent manner. In contrast, IL-10 responses in both cell types were PI 3-kinase/Akt-dependent. C. jejuni strains showed diverse levels of invasion with high invasion dependent on MAP kinase signaling in both cell lines. C. jejuni induced diverse cytotoxic responses in both cell lines with cdt-positive isolates showing significantly higher toxicity. Blockade of endocytic pathways suggested that invasion by C. jejuni was clathrin- and dynamin-dependent but caveolae- independent in both cells. In contrast, IL-8 (and CXCLi1/2 production was dependent on clathrin, dynamin, and caveolae. This study is important because of its scale, and the data produced, suggesting that avian and human epithelial cells use similar innate immune pathways where the magnitude of the response is determined by the phenotypic diversity of the Campylobacter species.

  19. Ephrin-B reverse signaling induces expression of wound healing associated genes in IEC-6 intestinal epithelial cells

    Institute of Scientific and Technical Information of China (English)

    Christian Hafner; Stefanie Meyer; Ilja Hagen; Bernd Becker; Alexander Roesch; Michael Landthaler; Thomas Vogt

    2005-01-01

    AIM: Eph receptors and ephrin ligands play a pivotal role in development and tissue maintenance. Since previous data have indicated an involvement of ephrin-B2 in epithelial healing, we investigated the gene expression and downstream signaling pathways induced by ephrin-B mediated cell-cell signaling in intestinal epithelial cells.METHODS: Upon stimulation of ephrin-B pathways in IFC-6 cells with recombinant rat EphB1-Fc, gene expression was analyzed by Affymetrix(R) rat genome 230 high density arrays at different time points. Differentially expressed genes were confirmed by real-time RT-PCR. In addition, MAP kinase pathways and focal adhesion kinase (FAK) activation downstream of ephrin-B were investigated by immunoblotting and fluorescence microscopy.RESULTS: Stimulation of the ephrin-B reverse signaling pathway in IEC-6 cells induces predominant expression of genes known to be involved into wound healing/cell migration, antiapoptotic pathways, host defense and inflammation. Cox-2, c-Fos, Egr-1, Egr-2, and MCP-1 were found among the most significantly regulated genes.Furthermore, we show that the expression of repairrelated genes is also accompanied by activation of the ERK1/2 MAP kinase pathway and FAK, two key regulators of epithelial restitution.CONCLUSION: Stimulation of the ephrin-B reverse signaling pathway induces a phenotype characterized by upregulation of repair-related genes, which may partially be mediated by ERK1/2 pathways.

  20. Cellular chloride and bicarbonate retention alters intracellular pH regulation in Cftr KO crypt epithelium.

    Science.gov (United States)

    Walker, Nancy M; Liu, Jinghua; Stein, Sydney R; Stefanski, Casey D; Strubberg, Ashlee M; Clarke, Lane L

    2016-01-15

    Cystic fibrosis (CF) is caused by mutations in the CF transmembrane conductance regulator (CFTR), an anion channel providing a major pathway for Cl(-) and HCO3 (-) efflux across the apical membrane of the epithelium. In the intestine, CF manifests as obstructive syndromes, dysbiosis, inflammation, and an increased risk for gastrointestinal cancer. Cftr knockout (KO) mice recapitulate CF intestinal disease, including intestinal hyperproliferation. Previous studies using Cftr KO intestinal organoids (enteroids) indicate that crypt epithelium maintains an alkaline intracellular pH (pHi). We hypothesized that Cftr has a cell-autonomous role in downregulating pHi that is incompletely compensated by acid-base regulation in its absence. Here, 2',7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein microfluorimetry of enteroids showed that Cftr KO crypt epithelium sustains an alkaline pHi and resistance to cell acidification relative to wild-type. Quantitative real-time PCR revealed that Cftr KO enteroids exhibit downregulated transcription of base (HCO3 (-))-loading proteins and upregulation of the basolateral membrane HCO3 (-)-unloader anion exchanger 2 (Ae2). Although Cftr KO crypt epithelium had increased Ae2 expression and Ae2-mediated Cl(-)/HCO3 (-) exchange with maximized gradients, it also had increased intracellular Cl(-) concentration relative to wild-type. Pharmacological reduction of intracellular Cl(-) concentration in Cftr KO crypt epithelium normalized pHi, which was largely Ae2-dependent. We conclude that Cftr KO crypt epithelium maintains an alkaline pHi as a consequence of losing both Cl(-) and HCO3 (-) efflux, which impairs pHi regulation by Ae2. Retention of Cl(-) and an alkaline pHi in crypt epithelium may alter several cellular processes in the proliferative compartment of Cftr KO intestine.

  1. Protein Malnutrition Modifies Innate Immunity and Gene Expression by Intestinal Epithelial Cells and Human Rotavirus Infection in Neonatal Gnotobiotic Pigs

    Science.gov (United States)

    Paim, Francine C.; Kandasamy, Sukumar; Alhamo, Moyasar A.; Fischer, David D.; Langel, Stephanie N.; Deblais, Loic; Kumar, Anand; Chepngeno, Juliet; Shao, Lulu; Huang, Huang-Chi; Candelero-Rueda, Rosario A.; Rajashekara, Gireesh

    2017-01-01

    ABSTRACT Malnutrition affects millions of children in developing countries, compromising immunity and contributing to increased rates of death from infectious diseases. Rotavirus is a major etiological agent of childhood diarrhea in developing countries, where malnutrition is prevalent. However, the interactions between the two and their combined effects on immune and intestinal functions are poorly understood. In this study, we used neonatal gnotobiotic (Gn) pigs transplanted with the fecal microbiota of a healthy 2-month-old infant (HIFM) and fed protein-deficient or -sufficient bovine milk diets. Protein deficiency induced hypoproteinemia, hypoalbuminemia, hypoglycemia, stunting, and generalized edema in Gn pigs, as observed in protein-malnourished children. Irrespective of the diet, human rotavirus (HRV) infection early, at HIFM posttransplantation day 3 (PTD3), resulted in adverse health effects and higher mortality rates (45 to 75%) than later HRV infection (PTD10). Protein malnutrition exacerbated HRV infection and affected the morphology and function of the small intestinal epithelial barrier. In pigs infected with HRV at PTD10, there was a uniform decrease in the function and/or frequencies of natural killer cells, plasmacytoid dendritic cells, and CD103+ and apoptotic mononuclear cells and altered gene expression profiles of intestinal epithelial cells (chromogranin A, mucin 2, proliferating cell nuclear antigen, SRY-Box 9, and villin). Thus, we have established the first HIFM-transplanted neonatal pig model that recapitulates major aspects of protein malnutrition in children and can be used to evaluate physiologically relevant interventions. Our findings provide an explanation of why nutrient-rich diets alone may lack efficacy in malnourished children. IMPORTANCE Malnutrition and rotavirus infection, prevalent in developing countries, individually and in combination, affect the health of millions of children, compromising their immunity and increasing

  2. Gut microbiome-derived metabolites modulate intestinal epithelial cell damage and mitigate graft-versus-host disease.

    Science.gov (United States)

    Mathewson, Nathan D; Jenq, Robert; Mathew, Anna V; Koenigsknecht, Mark; Hanash, Alan; Toubai, Tomomi; Oravecz-Wilson, Katherine; Wu, Shin-Rong; Sun, Yaping; Rossi, Corinne; Fujiwara, Hideaki; Byun, Jaeman; Shono, Yusuke; Lindemans, Caroline; Calafiore, Marco; Schmidt, Thomas C; Honda, Kenya; Young, Vincent B; Pennathur, Subramaniam; van den Brink, Marcel; Reddy, Pavan

    2016-05-01

    The effect of alterations in intestinal microbiota on microbial metabolites and on disease processes such as graft-versus-host disease (GVHD) is not known. Here we carried out an unbiased analysis to identify previously unidentified alterations in gastrointestinal microbiota-derived short-chain fatty acids (SCFAs) after allogeneic bone marrow transplant (allo-BMT). Alterations in the amount of only one SCFA, butyrate, were observed only in the intestinal tissue. The reduced butyrate in CD326(+) intestinal epithelial cells (IECs) after allo-BMT resulted in decreased histone acetylation, which was restored after local administration of exogenous butyrate. Butyrate restoration improved IEC junctional integrity, decreased apoptosis and mitigated GVHD. Furthermore, alteration of the indigenous microbiota with 17 rationally selected strains of high butyrate-producing Clostridia also decreased GVHD. These data demonstrate a heretofore unrecognized role of microbial metabolites and suggest that local and specific alteration of microbial metabolites has direct salutary effects on GVHD target tissues and can mitigate disease severity.

  3. Cellular mechanisms underlying the inhibitory effect of flufenamic acid on chloride secretion in human intestinal epithelial cells

    Directory of Open Access Journals (Sweden)

    Pawin Pongkorpsakol

    2017-06-01

    Full Text Available Intestinal Cl− secretion is involved in the pathogenesis of secretory diarrheas including cholera. We recently demonstrated that flufenamic acid (FFA suppressed Vibrio cholerae El Tor variant-induced intestinal fluid secretion via mechanisms involving AMPK activation and NF-κB-suppression. The present study aimed to investigate the effect of FFA on transepithelial Cl− secretion in human intestinal epithelial (T84 cells. FFA inhibited cAMP-dependent Cl− secretion in T84 cell monolayers with IC50 of ∼8 μM. Other fenamate drugs including tolfenamic acid, meclofenamic acid and mefenamic acid exhibited the same effect albeit with lower potency. FFA also inhibited activities of CFTR, a cAMP-activated apical Cl− channel, and KCNQ1/KCNE3, a cAMP-activated basolateral K+ channel. Mechanisms of CFTR inhibition by FFA did not involve activation of its negative regulators. Interestingly, FFA inhibited Ca2+-dependent Cl− secretion with IC50 of ∼10 μM. FFA inhibited activities of Ca2+-activated Cl− channels and KCa3.1, a Ca2+-activated basolateral K+ channels, but had no effect on activities of Na+–K+–Cl− cotransporters and Na+–K+ ATPases. These results indicate that FFA inhibits both cAMP and Ca2+-dependent Cl− secretion by suppressing activities of both apical Cl− channels and basolateral K+ channels. FFA and other fenamate drugs may be useful in the treatment of secretory diarrheas.

  4. Fluorescently labeled methyl-beta-cyclodextrin enters intestinal epithelial Caco-2 cells by fluid-phase endocytosis.

    Directory of Open Access Journals (Sweden)

    Ferenc Fenyvesi

    Full Text Available Cyclodextrins are widely used excipients for increasing the bioavailability of poorly water-soluble drugs. Their effect on drug absorption in the gastrointestinal tract is explained by their solubility- and permeability-enhancement. The aims of this study were to investigate penetration properties of fluorescently labeled randomly methylated-beta-cyclodextrin (FITC-RAMEB on Caco-2 cell layer and examine the cellular entry of cyclodextrins on intestinal cells. The permeability of FITC-RAMEB through Caco-2 monolayers was very limited. Using this compound in 0.05 mM concentration the permeability coefficient was 3.35±1.29×10(-8 cm/s and its permeability did not change in the presence of 5 mM randomly methylated-beta-cyclodextrin. Despite of the low permeability, cellular accumulation of FITC-RAMEB in cytoplasmic vesicles was significant and showed strong time and concentration dependence, similar to the characteristics of the macropinocytosis marker Lucifer Yellow. The internalization process was fully inhibited at 0°C and it was drastically reduced at 37°C applying rottlerin, an inhibitor of macropinocytosis. Notably, FITC-RAMEB colocalized with the early endosome organizer Rab5a. These results have revealed that FITC-RAMEB is able to enter intestinal epithelial cells by fluid-phase endocytosis from the apical side. This mechanism can be an additional process which helps to overcome the intestinal barrier and contributes to the bioavailability enhancement of cyclodextrins.

  5. Direct effect of croton oil on intestinal epithelial cells and colonic smooth muscle cells

    Institute of Scientific and Technical Information of China (English)

    Xin Wang; Mei Lan; Han-Ping Wu; Yong-Quan Shi; Ju Lu; Jie Ding; Kai-Cun Wu; Jian-Ping Jin; Dai-Ming Fan

    2002-01-01

    AIM: To investigate the direct effect of croton oil (CO) onhuman intestinal epithelial cells (HIEC) and guinea pigcolonic smooth muscle cells in vitro.METHODS: Growth curves of HIEC were drawn by MTTcolorimetry. The dynamics of cell proliferation was analyzedwith flow cytometry, and morphological changes wereobserved under light and electron microscopy after long-term (6 weeks) treatment with CO. Expression of cyclo-oxygenase2 (COX-2) mRNA was detected by dot blot inHIEC treated with CO. Genes related to CO were screenedby DD-PCR, and the direct effect of CO on the contractilityof isolated guinea pig colonic smooth muscle cells wasobservedRESULTS: High concentration (20- 40 mg @ L 1) Coinhibited cell growth significantly (1, 3, 5, 7d OD sequence:(20 mg@L 1) 0.040± 0.003, 0.081 ± 0.012, 0.147± 0.022,0.024± 0.016; (40 mg@ L-1) 0.033 ± 0.044, 0.056 ± 0.012,0.104 ± 0.010, 0. 189 ± 0.006; OD eontrol 0.031 ± 0.008, 0.096± 0.012, 0.173 ± 0.009, 0.300 ± 0.016, P < 0.01), whichappeared to be related directly to the dosage. Comparedwith the control, the fraction number of cells in G1 phasedecreased from 0.60 to 0.58, while that in S phase increasedfrom 0.30 to 0.34, and DNA index also increased after 6weeks of treatment with CO (the dosage was increasedgradually from 4 to 40 rg@ L-1 ). Light microscopicobservation revealed that cells had karyomegaly, lessplasma and karyoplasm lopsidedness. Electron microscopyalso showed an increase in cell proliferation and in thequantity of abnormal nuclei with pathologic mitosis.Expression of COX-2 mRNA decreased significantly in HIECtreated with CO. Thirteen differential cDNA fragments werecloned from HIEC treated with CO, one of which was 100percent homologous with human mitochondrial cytochromeC oxidase subunit Ⅱ. The length of isolated guinea pigcolonic smooth muscle cells was significantly shortenedafter treatment with CO ( P < 0.05).CONCLUSION: At a high CO concentration ( > 20 mg@ L 1 ),cell growth and

  6. A study of the effects of pinealectomy on intestinal cell proliferation in infant newborn rats

    Directory of Open Access Journals (Sweden)

    Dalio Marcelo Belini

    2006-01-01

    Full Text Available PURPOSE: Study the proliferation rate of jejunum and large intestine crypt epithelial cells, in rats pinealectomized immediately after borning. METHODS: Twenty-four male Wistar rats were distributed into two groups: Acute group (n=12 and Chronic group (n=12. Six animals of each group were operated for removal of the pineal gland (pinealectomy-PnX, and other six were controls (sham pinealectomy-C. Animals from acute and chronic group were sacrificed 15 and 90 days after the surgery, respectively. RESULTS: In acute group, pinealectomy of new-born rats has not caused significant alteration in cell proliferation (PnX=58,77?1,77 and C=60,88?1,10 in the descending colon/ PnX=31,56?0,45 and C=31,73?0,47 in the proximal jejunum and in crypt cell population (PnX=24,92?4,82 and C=23,60?2,48 in the descending colon/ PnX=39,92?3,49 and C=44,32?5,56 in the proximal jejunum. However, in chronic group there was an uprising crypt cell production per crypt in the proximal jejunum (PnX=57,54?2,19 and C=47,19?7,3and in the descending colon (PnX=37,78?2,22 and C=17,92?2,28. CONCLUSION: As the increase of intestinal crypts epithelial cells in chronic group is a carcinogenesis predetermining factor, the understanding of the interaction between pineal gland and this event has great importance.

  7. Fasting protects mice from lethal DNA damage by promoting small intestinal epithelial stem cell survival

    OpenAIRE

    2015-01-01

    Cancer patients undergoing chemotherapy experience high rates of dose-limiting morbidity. Recently, short-term fasting prior to chemotherapy was shown to decrease toxicity. Herein we report that fasting protects multiple small intestinal stem cell populations marked by Lgr5, Bmi1, or HopX expression and maintains barrier function to preserve small intestinal architecture from lethal DNA damage. Our findings provide insight into how fasting protects the host from toxicity associated with high-...

  8. Immunobiotic Lactobacillus rhamnosus strains differentially modulate antiviral immune response in porcine intestinal epithelial and antigen presenting cells

    Science.gov (United States)

    2014-01-01

    Background Previous findings suggested that Lactobacillus rhamnosus CRL1505 is able to increase resistance of children to intestinal viral infections. However, the intestinal cells, cytokines and receptors involved in the immunoregulatory effect of this probiotic strain have not been fully characterized. Results We aimed to gain insight into the mechanisms involved in the immunomodulatory effect of the CRL1505 strain and therefore evaluated in vitro the crosstalk between L. rhamnosus CRL1505, porcine intestinal epithelial cells (IECs) and antigen presenting cells (APCs) from swine Peyer’s patches in order to deepen our knowledge about the mechanisms, through which this strain may help preventing viral diarrhoea episodes. L. rhamnosus CRL1505 was able to induce IFN–α and –β in IECs and improve the production of type I IFNs in response to poly(I:C) challenge independently of Toll-like receptor (TLR)-2 or TLR9 signalling. In addition, the CRL1505 strain induced mRNA expression of IL-6 and TNF-α via TLR2 in IECs. Furthermore, the strain significantly increased surface molecules expression and cytokine production in intestinal APCs. The improved Th1 response induced by L. rhamnosus CRL1505 was triggered by TLR2 signalling and included augmented expression of MHC-II and co-stimulatory molecules and expression of IL-1β, IL-6, and IFN-γ in APCs. IL-10 was also significantly up-regulated by CRL1505 in APCs. Conclusions It was recently reviewed the emergence of TLR agonists as new ways to transform antiviral treatments by introducing panviral therapeutics with less adverse effects than IFN therapies. The use of L. rhamnosus CRL1505 as modulator of innate immunity and inductor of antiviral type I IFNs, IFN-γ, and regulatory IL-10 clearly offers the potential to overcome this challenge. PMID:24886142

  9. Cellular zinc is required for intestinal epithelial barrier maintenance via the regulation of claudin-3 and occludin expression.

    Science.gov (United States)

    Miyoshi, Yuka; Tanabe, Soichi; Suzuki, Takuya

    2016-07-01

    Intracellular zinc is required for a variety of cell functions, but its precise roles in the maintenance of the intestinal tight junction (TJ) barrier remain unclear. The present study investigated the essential roles of intracellular zinc in the preservation of intestinal TJ integrity and the underlying molecular mechanisms. Depletion of intracellular zinc in both intestinal Caco-2 cells and mouse colons through the application of a cell-permeable zinc chelator N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN) induced a disruption of the TJ barrier, as indicated by increased FITC-labeled dextran flux and decreased transepithelial electrical resistance. The TPEN-induced TJ disruption is associated with downregulation of two TJ proteins, occludin and claudin-3. Biotinylation of cell surface proteins revealed that the zinc depletion induced the proteolysis of occludin but not claudin-3. Occludin proteolysis was sensitive to the inhibition of calpain activity, and increased calpain activity was observed in the zinc-depleted cells. Although quantitative PCR analysis and promoter reporter assay have demonstrated that the zinc depletion-induced claudin-3 downregulation occurred at transcriptional levels, a site-directed mutation in the egr1 binding site in the claudin-3 prom