OBJECTIVETo investigate the expression of R-spondin1 (RSpo1) in the intestinal epithelium of mice with intestinal ischemia-reperfusion injury and explore its significance.

METHODSFifty normal male Kunming mice were randomized into sham-operated group (n=10) and intestinal ischemia-reperfusion injury group (n=40), and in the latter group, the mice were subjected to 20-min intestinal mesenteric artery occlusion followed by reperfusion for 6, 12, 24, or 48 h. Enzyme-linked immunosorbent assay (ELISA) and RT-PCR were used to detect intestinal RSpo1 expression of the mice.

RESULTSThe results of RT-PCR and ELISA showed that RSpo1 expression was significantly decreased in mice at 6 h of reperfusion following the intestinal ischemia (P<0.05), and increased gradually with prolonged repersuion time, reaching the peak level at 24 h (P<0.05). The expression underwent rapid decrease afterwards to a significantly lower level than that in the control group at 48 h (P<0.05).

CONCLUSIONIntestinal ischemia-reperfusion injury may inhibit expression of RSpo1 in the early stage, and enhance its expression in the middle stage. RSpo1 can promote proliferation and differentiation of intestinal epithelial stem cells and plays an important role in the repair intestinal mucosal damage.

Animals ; Cell Proliferation ; Intestinal Mucosa ; cytology ; metabolism ; Intestines ; blood supply ; metabolism ; Male ; Mice ; Random Allocation ; Reperfusion Injury ; metabolism ; Stem Cells ; cytology ; Thrombospondins ; genetics ; metabolism

OBJECTIVETo investigate the changes of the goblet cells in the intestine during the restitution process of the gut barrier after hemorrhagic shock.

METHODSForty-nine Sprague-Dawley rats with body weight of 250-300 g were divided into control group (n=7) and experimental group (n=42). Rats in the experimental group was further divided into 6 groups (n=7 each) according to different time point at 1, 3, 6, 12, 24, and 36 hours after hemorrhagic shock resuscitation. The specimens from ileum tissue were taken to observe the morphological chan ges of the intestinal mucosa. The number of goblet cells was determined by light microscope and/or electron microscope. The contents of trefoil factor family 3 (TFF3) of goblet cells were examined using GC-9A gas chromatographic instrument.

RESULTSAfter hemorrhagic shock, mucosal epithelial injury was obvious in the small intestine. Tissue restitution was found after 3 hours, and mostly established after 12 hours. Following tissue restitution,the denuded mucosal surface was covered intensively by goblet cells. The number of goblet cells on the intestinal mucosa was reduced significantly from 243+/- 13 at 1 h to 157+/- 9 at 24 h (r=- 0.910, P< 0.01), and returned to normal level at 36 h. In the experimental group, the content of TFF3 in the intestinal mucosa increased significantly at 12 hours, decreased, but was still higher at 24 hours (t=3.24, P< 0.05).

CONCLUSIONSThe goblet cells play a key role in the restitution of intestinal mucosa. High expression of TFF3 may facilitate the intestinal mucosal restitution in the early phase.

Animals ; Goblet Cells ; metabolism ; Ileum ; cytology ; Intestinal Mucosa ; cytology ; metabolism ; pathology ; Neuropeptides ; metabolism ; Rats ; Rats, Sprague-Dawley ; Shock, Hemorrhagic ; metabolism ; Trefoil Factor-3

OBJECTIVE: To explore the molecular mechanisms of colonic epithelial aging related proteins and aged colonic epithelial susceptibility to tumor. METHODS: The proteins of normal human colonic epithelial tissue from young and old people were separated by 2-dimensional gel electrophoresis (2DGE), respectively. Then gels were stained by silver, scanned by imagescanner and analyzed with PDQuest software. The differentially expressed protein spots of colonic epithelium between the old and the young groups were identified by peptide mass fingerprint based on matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) and database searching. RESULTS: Well-resolved and reproducible 2DGE maps of normal human colonic epithelium from the young and the old were acquired. Nineteen more than 2 fold differentially expressed protein spots were identified representing 17 different proteins by MALDI-TOF-MS. The functions of these proteins involve in metabolism, energy generation, transportation, antioxidation, translation and protein folding. CONCLUSION Seventeen aging related proteins of human colonic epithelium identified indicate that injury of mitochondrial function and decline of antioxidant capability are important reasons for the aging of human colonic epithelium. These data provided useful clues for elucidating the mechanisms of colonic epithelial aging and aged colonic epithelial susceptibility to cancer.
Aging ; metabolism ; Cells, Cultured ; Cellular Senescence ; genetics ; Chloride Channels ; biosynthesis ; genetics ; Colon ; cytology ; Electron-Transferring Flavoproteins ; biosynthesis ; genetics ; Epithelial Cells ; cytology ; Humans ; Intestinal Mucosa ; cytology ; Proteins ; metabolism

Dendritic cells (DCs) are key modulators that shape the immune system. In mucosal tissues, DCs act as surveillance systems to sense infection and also function as professional antigen-presenting cells that stimulate the differentiation of naive T and B cells. On the basis of their molecular expression, DCs can be divided into several subsets with unique functions. In this review, we focus on intestinal DC subsets and their function in bridging the innate signaling and adaptive immune systems to maintain the homeostasis of the intestinal immune environment. We also review the current strategies for manipulating mucosal DCs for the development of efficient mucosal vaccines to protect against infectious diseases.
Animals ; Dendritic Cells/*immunology/metabolism ; Humans ; Immunity, Mucosal ; Intestinal Mucosa/cytology/*immunology ; T-Lymphocytes, Helper-Inducer/immunology

OBJECTIVETo observe the effect of SIRT1 on intestinal barrier function of epithelial Caco-2 cells under hypoxia and investigate its mechanism.

METHODSCaco-2 cells were randomly divided into three groups: normoxia group (Nx), hypoxia group (Hx,1%O2 for 6 h) and hypoxia plus 40 μmol/L Resveratrol (agonist of SIRT1) group (Hx+Res). Transepithelial electrical resistance (TER) was determined. mRNA and protein expressions of SIRT1 and tight junctions (ZO-1, Occludin, Claudin-1) were examined by reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting.

RESULTSBoth mRNA and protein expressions of SIRT1 were significantly reduced in Hx group as compared with Nx group (0.40±0.02 vs. 0.70±0.07, P=0.001; 0.37±0.03 vs. 0.76±0.03, P=0.001). The mRNA and protein expressions of SIRT1 were significantly increased in Hx+Res group as compared with Hx group(0.50±0.02 vs. 0.40±0.02, P=0.026; 0.54±0.02 vs. 0.37±0.03, P=0.011). The expression levels of ZO-1, Occludin and Claudin-1 in Hx group were lower than those in Nx group (P<0.05), however, pretreatment with Resveratrol could attenuate the decreased expression of above 3 molecules under hypoxia(P<0.05). TERs of Nx group, Hx group and Hx+Res group were (142±7) Ohm/cm(2), (94±3) Ohm/cm(2) and (119±7) Ohm/cm(2) respectively. Compare with the Nx group, the TER of Hx group was significantly decreased(P<0.05). TER of Hx+Res group was significantly increased compare with Hx group, but it was still significantly lower than that in Nx group(P<0.05).

CONCLUSIONSExpression of SIRT1 is significantly reduced under hypoxia. Activation of SIRT1 can maintain the epithelial barrier function through regulating the expression of tight junctions under hypoxia.

Caco-2 Cells ; Cell Hypoxia ; Claudin-1 ; metabolism ; Epithelial Cells ; metabolism ; Humans ; Intestinal Mucosa ; cytology ; Occludin ; metabolism ; Sirtuin 1 ; metabolism ; Zonula Occludens-1 Protein ; metabolism

OBJECTIVETo predict the absorption of corynanthine (COR), yohimbine (YOH), ajmalicine (AMC) and ajmaline (AML) as chemical constituents of some traditional Chinese medicines in human intestinal epithelial.

METHODBy using Caco-2 (the human colonic adenocarcinoma cell lines) cell monolayers as a human intestinal epithelial cell model, the permeability of COR, YOH, AMC and AML were studied from apical side (AP side) to basolateral side (BL side) or from BL side to AP side. The four alkaloids were measured by high performance liquid chromatography (HPLC) coupled with UV detector. Transport parameters and apty) and atenolol (a control substance of poor permeability). The relationship between P(app) and log D values of four alkaloids was investigated by using drugs ADMET predict software.

RESULTThe P(app) values of COR, YOH, AMC and AML were (1.863 +/- 0.055) x 10(-5), (1.540 +/- 0.082) x 10(-5), (2.522 +/- 0.246) x 10(-5) and (1.155 +/- 0.099) x 10(-5) cm x s(-1) from AP side to BL side, and (2.390 +/- 0.017) x 10(-5), (1.987 +/- 0.154) x 10(-5), (1.374 +/- 0.260) x 10(-5) and (2.418 +/- 0.124) x 10(-5) cm x s(-1) from BL side to AP side, respectively, which P(app) values were identical with that of propranolol [(2.23 +/- 0.10) x 10(-5) cm x s(-1) from AP to BL side]. The ratio of P(app B --> A)/P(app A -->B) of COR, YOH, AMC and AML were 1.28, 1.29, 0.54 and 2.09, respectively, which suggested that the efflux transport of AML was 2.09 times higher more than its influx transport.

CONCLUSIONCOR, YOH, AMC and AML can be transported and absorbed across the human Caco-2 cells monolayers, and they belong to completely absorbed compounds. AML may have been involved in efflux mechanism in Caco-2 cells monolayers model from the BL to AP side direction. The oil-water partition coefficient play key roles in the transport and absorption of the four alkaloids.

Ajmaline ; metabolism ; Caco-2 Cells ; Chromatography, High Pressure Liquid ; Epithelial Cells ; metabolism ; Humans ; Intestinal Mucosa ; cytology ; Molecular Structure ; Secologanin Tryptamine Alkaloids ; metabolism ; Yohimbine ; metabolism

OBJECTIVETo study the role of myosin light chain kinase (MLCK) in intestinal epithelial barrier dysfunction after hypoxia.

METHODSThe Caco-2 monolayers developed with Transwell inserts were exposed to hypoxia for 0 h (NC group), 2, 6, 8, 12 and 24 h (H group), and 6 h hypoxic specimens were treated with 100 mol/L ML-9 (T group). The transepithelial electrical resistance (TER) of monolayers was measured with an ohmmeter. The tight junction protein ZO-1 of monolayers was analyzed by immunofluorescence assay. The protein expressions of phosphorylated myosin light chain (p-MLC) and MLCK were detected by Western blotting.

RESULTSThe TER of monolayers in H group at 6, 8, 12 and 24 h was 422 +/- 17, 427 +/- 27, 403 +/- 40 and 426 +/- 22 ohms respectively, which was significantly lower than that of NC group (451 +/- 27 ohms, P < 0.05). The TER of monolayers in T group was 558 +/- 110 ohms, which was significantly higher than that in H group at each time point ( P < 0.01). The ZO-1 of monolayers in H group at 6 h was irregular in arrangement, with interruptions and rugae, and sawtooth. These abnormalities were ameliorated in T group (regular in arrangement, with little or without ruga and sawtooth). The protein expressions of p-MLC and MLCK in H group at each time point were higher than those in NC group.

CONCLUSIONSIntestinal epithelial barrier dysfunction after hypoxia can be mediated by MLCK.

Caco-2 Cells ; Epithelium ; metabolism ; physiopathology ; Humans ; Hypoxia ; metabolism ; physiopathology ; Intestinal Absorption ; Intestinal Mucosa ; metabolism ; physiopathology ; Intestines ; cytology ; metabolism ; physiopathology ; Myosin Light Chains ; metabolism ; Myosin-Light-Chain Kinase ; metabolism

OBJECTIVETo study the effect of berberine on the release of nitric oxide (NO) by rat intestinal mucous microvascular endothelial cells (RIMECs) cultured in vitro for exploring the pharmacological mechanism of berberine in treating intestinal disease.

METHODSCultured RIMECs in vitro were identified adopting immunofluorescent stain with factor VIII-related antigen. NO level in the supernatant of normal cell culture or cell culture treated with different concentrations of berberine was detected with colorimetry at the 3rd, 6th, 9th and 12th h and compared.

RESULTSCompared with that in the normal control group, NO level increased more obviously in the berberine treated groups, and the best effect was shown in the 5 microg/mL berberine treated group.

CONCLUSIONOne of the important pharmacological mechanisms of berberine might be through promoting the endogenous NO release to induce endothelium-dependent dilatation of microvascular in intestinal mucosa, thus to improve the local microcirculation of intestine.

Animals ; Berberine ; pharmacology ; Cells, Cultured ; Colorimetry ; Endothelial Cells ; cytology ; drug effects ; metabolism ; Intestinal Mucosa ; blood supply ; cytology ; Nitric Oxide ; biosynthesis ; Rats ; Time Factors

OBJECTIVETo investigate the distribution of mast cells (MC) in colon tissue of Hirschsprung disease (HD) and explore the role of mast cells in the pathogenesis of HD.

METHODSForty-one cases of HD (male 23, female 18), age from 2 months to 15 years, and eight age-matched normal cases were enrolled in this study. The distribution of MC in all layers of colon was examined by immunohistochemistry with mouse antihuman mast cell tryptase monoclonal antibody.

RESULTSThe count of MC in all layers of colon aganglionic segments of HD was significantly higher as compared with colon ganglionic segments of HD and normal controls (21.47+/-3.59 vs 3.18+/-0.87, 2.75+/-0.51). The average optical density values(A) of MC in aganglionic and ganglionic segments significantly decreased as compared to normal control (0.38+/-0.10,0.31+/-0.11 vs 0.51+/-0.08).

CONCLUSIONMast cells may play an important role in the pathogenesis of HD.

Adolescent ; Child ; Child, Preschool ; Female ; Hirschsprung Disease ; metabolism ; pathology ; Humans ; Infant ; Intestinal Mucosa ; pathology ; Male ; Mast Cells ; cytology ; metabolism ; pathology ; Tryptases ; metabolism

The objective of this study is to investigate the permeabilities of rebamipide across the jejunal, ileal and colonic membranes in rat. The permeability (Papp) of rebamipide via rat intestinal membranes at concentration of 80 micromol L(-1) was evaluated by an in vitro diffusion chamber system after the membranes were isolated from the rat intestine. And the concentration of rebamipide in the receptor was determined by HPLC. As a result, the permeability of rebamipide across the jejunal or ileal membrane was higher than that across the colonic membrane, and the permeability of rebamipide in the ileal tissue from the serosal to mucosal direction was greater than that from the mucosal to serosal direction. Therefore, there was a regional difference in the permeability of rabamipide across the jejunum, ileum and the colon in rat. Also, the transporters in the intestinal mucosa as p-glycoprotein may not be involved in the transport of rebamipide.
Alanine ; analogs & derivatives ; pharmacokinetics ; Animals ; Antioxidants ; pharmacokinetics ; Biological Transport ; Cell Membrane Permeability ; Colon ; metabolism ; Female ; Humans ; Ileum ; metabolism ; Intestinal Absorption ; Intestinal Mucosa ; metabolism ; Intestines ; cytology ; metabolism ; Jejunum ; metabolism ; Male ; Permeability ; Quinolones ; pharmacokinetics ; Rats ; Rats, Wistar