Influence of antimicrotubular drugs on the Golgi apparatus of stomach secretory mucoid cells and small intestine absorptive cells

Virchows Archiv B Cell Pathology - The effects of vinblastine and colchicine on the Golgi apparatus of stomach surface mucoid and absorptive intestinal cells were compared by cytochemical analysis....     

Alkaline phosphatase: keeping the peace at the gut epithelial surface

Vertebrate intestinal surfaces are in constant contact with a vast consortium of commensal bacteria. To preserve mutually beneficial host-microbial relationships, gut epithelia have evolved strategies to limit the proinflammatory potential of resident gut microbes. In this issue of Cell Host & Microbe, Bates and colleagues report that intestinal alkaline phosphatase, whose expression is induced during establishment of the microbiota, dephosphorylates lipopolysaccharide and promotes mucosal tolerance to commensal bacteria in zebrafish.     

Guts and glory: balancing microbes and the immune response

Maintaining balance with intestinal flora is an important activity of the immune system in higher metazoans. In this issue of Developmental Cell, Ha et al. demonstrate a central role of a redox balance in microbial interactions in the fruit fly gut.     

LncRNA Bmp1 promotes the healing of intestinal mucosal lesions via the miR-128-3p/PHF6/PI3K/AKT pathway

Intestinal mucosal injuries are directly or indirectly related to many common acute and chronic diseases. Long non-coding RNAs (lncRNAs) are expressed in many diseases, including intestinal mucosal injury. However, the relationship between lncRNAs and intestinal mucosal injury has not been determined. Here, we investigated the functions and mechanisms of action of lncRNA Bmp1 on damaged intestinal mucosa. We found that Bmp1 was increased in damaged intestinal mucosal tissue and Bmp1 overexpression was able to alleviate intestinal mucosal injury. Bmp1 overexpression was found to influence cell proliferation, colony formation, and migration in IEC-6 or HIEC-6 cells. Moreover, miR-128-3p was downregulated after Bmp1 overexpression, and upregulation of miR-128-3p reversed the effects of Bmp1 overexpression in IEC-6 cells. Phf6 was observed to be a target of miR-128-3p. Furthermore, PHF6 overexpression affected IEC-6 cells by activating PI3K/AKT signaling which was mediated by the miR-128-3p/PHF6 axis. In conclusion, Bmp1 was found to promote the expression of PHF6 through the sponge miR-128-3p, activating the PI3K/AKT signaling pathway to promote cell migration and proliferation.Subject terms: Cell growth, Cell migration     

Adherence of Vibrio parahaemolyticus to rabbit intestinal epithelial cells in vitro

Kanagawa positive strains of Vibrio parahaemolyticus showed adherence whereas most of the Kanagawa negative strains were non-adhering to rabbit intestinal epithelial cells. Anti-hemolysin antisera did not inhibit the adherence of V. parahaemolyticus strains. Moreover, the adhesive capacity of non-adhering strains was not enhanced by purified hemolysin. Cell surface hydrophobicity remained the same in both Kanagawa positive and negative strains of V. parahaemolyticus. Fetuin strongly inhibited the adherence to rabbit intestinal epithelial cells followed by -mannose and D-glucose.     

Stem cell fate in proliferating tissues: equal odds in a game of chance

Quantitative lineage tracing reveals stem cell fate in?vivo. A new study in a recent issue of Cell shows intestinal crypt stem cells are functionally equivalent, with equal odds of differentiation. Differentiating stem cells are replaced by the symmetric division of adjacent stem cells.     

Effect of Helicobacter pylori infection and eradication on gastric epithelial cell proliferation and apoptosis.

OBJECTIVES: the effect of Helicobacter pylori infection on gastric epithelial cell proliferation and apoptosis is still controversial. Our aim was to evaluate the effect of H. pylori infection on cell kinetic parameters in normal gastric epithelium, gastritis with/without intestinal metaplasia and gastric cancer. PATIENTS AND METHODS: antral biopsies were taken from 121 patients (61 women, 60 men, mean age 58.5+/-14.3 years of age) who underwent routine gastroscopy for upper gastrointestinal symptoms. Sections were scored for normal epithelia (n=15), gastritis without intestinal metaplasia (n=74), gastritis with intestinal metaplasia (n=24), and gastric adenocarcinoma (n=8). Fifty-two patients had H. pylori positive gastritis, and success of H. pylori eradication therapy was controlled in 12 cases, all with intestinal metaplasia. To characterize cell proliferation and assess apoptosis, immunohistochemistry [Proliferating Cell Nuclear Antigen (PCNA)], histochemistry [Argyrophil Nucleolar Organizer Regions (AgNOR)], and terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridinetriphosphate (dUTP) nick end-labeling (TUNEL) were used, respectively. RESULTS: both cell proliferation and apoptosis is was higher in chronic gastritis when compared with normal epithelia, but neither PCNA LI (54.79+/-19.1 vs. 53.20+/-20.7) nor AgNOR counts (291.43+/-44.3 vs. 277.8+/-57.54) were different in H. pylori positive versus negative chronic gastritis. A significant positive correlation (P<0.05) was found in this group between PCNA and AgNOR techniques. Apoptosis was significantly higher (P<0.05) in H. pylori positive cases only when intestinal metaplasia was not present. Cell proliferation in intestinal metaplasia decreased to the activity of normal epithelium after successful eradication of H. pylori but remained high if eradication therapy failed. CONCLUSIONS: epithelial cell proliferation does not depend on H. pylori status in chronic gastritis. H. pylori increases apoptosis only in the absence of intestinal metaplasia.     

Regulation of Human (Caco-2) Intestinal Epithelial Cell Differentiation by Extracellular Matrix Proteins

Extracellular matrix regulation of intestinal epithelial differentiation may affect development, differentiation during migration to villus tips, healing, inflammatory bowel disease, and malignant transformation. Cell culture studies of intestinal epithelial biology may also depend on the matrix substrate used. We evaluated matrix effects on differentiation and proliferation in human intestinal Caco-2 epithelial cells, a model for intestinal epithelial differentiation. Proliferation, brush border enzyme specific activity, and spreading were compared in cells cultured on tissue culture plastic with interstitial collagen I and the basement membrane constituents collagen IV and laminin. Each matrix significantly increased alkaline phosphatase, dipeptidyl peptidase, lactase, sucrase-isomaltase, and cell spreading in comparison to plastic. However, the basement membrane proteins collagen IV and laminin further promoted all four brush border enzymes but inhibited spreading compared to collagen I. Proliferation was most rapid on type I collagen and slowest on laminin and tissue culture plastic. Basement membrane matrix proteins may promote intestinal epithelial differentiation and inhibit proliferation compared with interstitial collagen I.     

THE ENDOCRINE CELLS IN THE EPITHELIUM OF THE GASTROINTESTINAL MUCOSA OF THE RAT : An Electron Microscope Study

The authors of this study examine the question of whether the so-called enterochromaffin or argentaffin cells of the gastrointestinal tract should be considered as a single cell type. The systematic application of purely morphologic methods has led to the conclusion that the epithelium of the gastrointestinal mucosa comprises endocrine cells of several types. This conclusion is primarily based on the uneven and characteristic distribution of the various cell types along the intestinal tract, an observation precluding the interpretation that the different types correspond to diverse functional stages of the same cell. A specific endocrine function may be attributed to each of the given cell types recognized so far on account of their appearance and their localization in characteristic areas of the gastrointestinal tract. It is acknowledged, however, that a purely morphological study leaves room for doubt. The first cell type is probably responsible for the formation of 5-hydroxytryptamine. Cells of type II are morphologically comparable to the pancreatic A cells and may, therefore, be called intestinal A cells. Cell type III comprises intestinal D cells since their appearance corresponds to that of pancreatic D cells. Cell type IV might well be responsible for catecholamine production, whereas gastrin is in all probability produced in endocrine cell type V. As yet, the thorough morphological study of the gastrointestinal epithelium does not provide information as to additional distinct cellular sites of production of the several other hormones isolated from different parts of the gut.     

The emerging role of ferroptosis in intestinal disease

Ferroptosis is a newly recognised type of regulated cell death (RCD) characterised by iron-dependent accumulation of lipid peroxidation. It is significantly distinct from other RCDs at the morphological, biochemical, and genetic levels. Recent reports have implicated ferroptosis in multiple diseases, including neurological disorders, kidney injury, liver diseases, and cancer. Ferroptotic cell death has also been associated with dysfunction of the intestinal epithelium, which contributes to several intestinal diseases. Research on ferroptosis may provide a new understanding of intestinal disease pathogenesis that benefits clinical treatment. In this review, we provide an overview of ferroptosis and its underlying mechanisms, then describe its emerging role in intestinal diseases, including intestinal ischaemia/reperfusion (I/R) injury, inflammatory bowel disease (IBD), and colorectal cancer (CRC).Subject terms: Cell death, Intestinal diseases     

Intestinal absorption and metabolism of carotenoids: insights from cell culture

Cell culture models are useful for studying intestinal absorption and metabolism of carotenoids. The human intestinal cell line, Caco-2, has been the most widely used model for these studies. The PF11 and TC7 clones of Caco-2 exhibit beta-carotene-15,15'-oxygenase activity, a key enzyme in the conversion of carotenoids to vitamin A. Studies on the recent cloning of this enzyme are discussed. An in vitro cell culture system used to study intestinal absorption of carotenoids is presented. Under conditions mimicking the postprandial state, Caco-2 cells on membranes take up carotenoids and secrete them incorporated into chylomicrons. Both the cellular uptake and secretion of beta-carotene are saturable, concentration-dependent processes. The selective absorption of all-trans beta-carotene versus its cis isomers, the differential absorption of individual carotenoids, and the specific interactions between carotenoids during their absorption are discussed. The participation of a specific epithelial transporter in the intestinal absorption of carotenoids is proposed.     

Enteric infection and inflammation alter gut microbial ecology

The complex microbial community residing within the intestine plays important roles in host defense. However, the impact of enteric infection and inflammation on this resident community has not been fully explored. In this issue of Cell Host & Microbe, Lupp and coworkers reveal that the composition of the intestinal microbiota changes in distinctive ways in response to infection and inflammation.     

Generation of Mouse Small Intestinal Epithelial Cell Lines That Allow the Analysis of Specific Innate Immune Functions

Cell lines derived from the small intestine that reflect authentic properties of the originating intestinal epithelium are of high value for studies on mucosal immunology and host microbial homeostasis. A novel immortalization procedure was applied to generate continuously proliferating cell lines from murine E19 embryonic small intestinal tissue. The obtained cell lines form a tight and polarized epithelial cell layer, display characteristic tight junction, microvilli and surface protein expression and generate increasing transepithelial electrical resistance during in vitro culture. Significant up-regulation of Cxcl2 and Cxcl5 chemokine expression upon exposure to defined microbial innate immune stimuli and endogenous cytokines is observed. Cell lines were also generated from a transgenic interferon reporter (Mx2-Luciferase) mouse, allowing reporter technology-based quantification of the cellular response to type I and III interferon. Thus, the newly created cell lines mimic properties of the natural epithelium and can be used for diverse studies including testing of the absorption of drug candidates. The reproducibility of the method to create such cell lines from wild type and transgenic mice provides a new tool to study molecular and cellular processes of the epithelial barrier.     

Establishment of primary bovine intestinal epithelial cell culture and clone method

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.     

Open sesame! Coxsackieviruses conspire to trespass the tight junctional gate

In the January 13 issue of Cell, Coyne and Bergelson describe an "Open sesame!" strategy developed by coxsackieviruses to invade the organism through the intestinal epithelium. The strategy involves coopting intrinsic signaling abilities of the apical GPI-anchored protein DAF to open the tight junction barrier, gain access to the primary receptor CAR, and activate virus internalization by a caveolin-dependent pathway.     

Does heme oxygenase-1 have a role in Caco-2 cell cycle progression?

Intestinal epithelium undergoes a rapid self-renewal process characterized by the proliferation of the crypt cells, their differentiation into mature enterocytes as they migrate up to the villi, followed by their shedding as they become senescent villus enterocytes. The exact mechanism that regulates the intestinal epithelium renewal process is not well understood, but the differential expression of regulatory genes along the crypt-villus axis may have a role. Heme oxygenase-1 (HO-1) is involved in endothelial cell cycle progression, but its role in the intestinal epithelial cell turnover has not been explored. With its effects on cell proliferation and its differential expression along the crypt-villus axis, HO-1 may play a role in the intestinal epithelial cell renewal process. In this study, we examined the role of HO-1 in the proliferation and differentiation of Caco-2 cells, a well-established in vitro model for human enterocytes. After confluence, Caco-2 cells undergo spontaneous differentiation and mimic the crypt to villus maturation observed in vivo. In preconfluent and confluent Caco-2 cells, HO-1 protein expression was determined with the immunoblot. HO-1 activity was determined by the ability of the enzyme to generate bilirubin from hemin. The effect of a HO-1 enzyme activity inhibitor, tin protoporphyrin (SnPP), on Caco-2 cell proliferation and differentiation was examined. In preconfluent cells, cell number was determined periodically as a marker of proliferation. Cell viability was measured with MTT assay. Cell differentiation was assessed by the expression of a brush border enzyme, alkaline phophatase (ALP). HO-1 was expressed in subconfluent Caco-2 cells and remained detectable until 2 days postconfluency. This timing was consistent with cells starting their differentiation and taking the features of normal intestinal epithelial cells. HO-1 was inducible in confluent Caco-2 cells by the enzyme substrate, hemin in a dose- and time-dependent manner. SnPP decreased the cell number and viability of preconfluent cells and delayed the ALP enzyme activity of confluent cells. HO-1 may be involved in intestinal cell cycle progression.     

Effect of myenteric denervation on intestinal epithelium proliferation and migration of suckling and weanling rats

The effects of myenteric denervation on the cell kinetics of the intestinal epithelium of suckling and weanling rats were investigated. The myenteric plexus of an ileal segment was partially ablated by serosal application of benzalkonium chloride (BAC) in three groups of rats: those that underwent surgery at 13 days and were killed 15 (13/28-day-old) or 23 (13/36-day-old) days after treatment, and those that were operated at 21 days (21/36-day-old) and were killed 15 days after treatment. The extent of denervation was assessed in whole-mount preparations. The cell bodies of myenteric neurones were stained by NADH-diaphorase histochemical technique. Cell proliferation was estimated by the mitotic index (MI) and morphometric analysis of villus and crypt lengths using an image analysis system. Thickness of the muscle layers was also assessed by morphometry. Cell migration on the villi was estimated by the position of the leading labelled cell 24 h after tritiated thymidine injection. The number of neurones was reduced by around 80% in rats operated at 13 days, and reduced by 98% in those operated at 21 days. The thickness of the muscle layers was increased in all groups of treated animals. MI was significantly higher 15 days after BAC-treatment in the 13/28 group. Morphological changes in the intestinal mucosa were observed 15 days after BAC-treatment, when there was an increase in villus height (13/28 group) and crypt depth (13/28 and 21/36 groups). Cell migration rate was accelerated in the 21/36 group. No differences where found in the 13/36 group. These results show the strong effect of myenteric ablation on cell proliferation and migration in the ileal epithelium in the first 15 days of treatment in suckling and in weanling rats, and the subsequent recovery of intestinal mucosa homeostasis later on.     

Differences in Survival among 13 Listeria monocytogenes Strains in a Dynamic Model of the Stomach and Small Intestine

Thirteen Listeria monocytogenes strains were compared for the ability to survive in a dynamic gastrointestinal model. Strains displayed various degrees of susceptibility to gastric acidity; however, strain-to-strain variations became evident mainly after 90 min of exposure (pH 2.0). Cell levels transferred to the intestine depended on initial populations, while reductions during intestinal exposure were relatively small for all strains.