Intestinal stem cells promote crypt fission during postnatal growth of the small intestine.

OBJECTIVE: Wnt-ß-catenin signalling is essential for intestinal stem cells. Our aim was to investigate the relationship between intestinal stem cells and crypt fission which peaks during infancy. DESIGN: Duodenal biopsies were obtained during endoscopy to assess the severity of reflux oesophagitis of 15 infants, children and teenagers, which would not affect the duodenum. Samples of small intestine were also obtained from rats 7-72 days of life. Crypt fission was assessed using microdissection of 100 whole crypts and recording the percentage of bifid crypts. Intestinal LGR5+ stem cells were identified by in situ hybridisation. Rats were treated with Dickkopf to block Wnt-ß-catenin signalling. RESULTS: Crypt fission peaked during infancy before declining after 3-4 years in humans and after 21 days of life in rats. Occasional mitotic figures were seen in bifid crypts during early fission. Stem cells were elevated for a greater period during infancy and childhood in humans. Clustering of Paneth cells was present around the stem cells at the crypt base. Dickkopf reduced the number of stem cells and crypt fission to 45% and 29%, respectively, of control values, showing dependence of both crypt fission and Lgr5+ stem cells on Wnt signalling. However, Dickkopf did not decrease mitotic count per crypt, indicating a difference in signalling between stem cells and their progeny in the transit amplifying zone. CONCLUSION: Crypt fission peaks during infancy and is dependent on intestinal stem cells. This is relatively hidden by 'a cloak of invisibility' due to the low proliferation of stem cells.

Active ß-Catenin Signaling in the Small Intestine of Humans During Infancy.

BACKGROUND: Wnt-ß-catenin signaling is essential for homeostasis of intestinal stem cells in mice and is thought to promote intestinal crypt fission. AIMS: The aim of this study was to investigate Wnt-ß-catenin signaling in intestinal crypts of human infants. METHODS: Duodenal biopsies from nine infants (mean, range 0.9 years, 0.3-2 years) and 11 adults (mean, range 43 years, 34-71 years) were collected endoscopically. Active ß-catenin signaling was assessed by cytoplasmic and nuclear ß-catenin, nuclear c-Myc, and cytoplasmic Axin-2 expression in the base of crypts. Tissues were stained by an immunoperoxidase staining technique and quantified as pixel energy using cumulative signal analysis. Data were expressed as mean ± SD and significance assessed by Student's t test. RESULTS: Crypt fission was significantly higher in infants compared to adults (16 ± 8.6% versus 0.7 ± 0.6%, respectively, p < 0.0001). Expression of cytoplasmic and nuclear ß-catenin was 1.8-fold (p < 0.0001) and 2.9-fold (p < 0.0001) higher in infants, respectively, while cytoplasmic Axin-2 was 3.1-fold (p < 0.0001) increased in infants. c-Myc expression was not significantly different between infants and adults. Expression was absent in Paneth cells but present in the transit amplifying zone of crypts. Crypt base columnar cells, which were intercalated between Paneth cells, expressed c-Myc. CONCLUSIONS: Wnt-ß-catenin signaling was active in crypt base columnar cells (i.e., intestinal stem cells) in human infants. This signaling could promote crypt fission during infancy. Wnt-ß-catenin signaling likely acts in concert with other pathways to promote postnatal growth.

A phase 2 study of allogeneic mesenchymal stromal cells for luminal Crohn's disease refractory to biologic therapy.

BACKGROUND & AIMS: Transplantation of peripheral blood stem cells has been successful therapy for small numbers of patients with Crohn's disease (CD), but requires prior myeloconditioning. Mesenchymal stromal cells (MSCs) escape immune recognition, so myeloconditioning is not required before their administration. We investigated the efficacy of allogeneic MSCs in patients with luminal CD. METHODS: Our phase 2, open-label, multicenter study included 16 patients (21-55 y old; 6 men) with infliximab- or adalimumab-refractory, endoscopically confirmed, active luminal CD (CD activity index [CDAI], >250). Subjects were given intravenous infusions of allogeneic MSCs (2 × 10(6) cells/kg body weight) weekly for 4 weeks. The primary end point was clinical response (decrease in CDAI >100 points) 42 days after the first MSC administration; secondary end points were clinical remission (CDAI, <150), endoscopic improvement (a CD endoscopic index of severity [CDEIS] value, <3 or a decrease by >5), quality of life, level of C-reactive protein, and safety. RESULTS: Among the 15 patients who completed the study, the mean CDAI score was reduced from 370 (median, 327; range, 256-603) to 203 (median, 129) at day 42 (P < .0001). The mean CDAI scores decreased after each MSC infusion (370 before administration, 269 on day 7, 240 on day 14, 209 on day 21, 182 on day 28, and 203 on day 42). Twelve patients had a clinical response (80%; 95% confidence interval, 72%-88%; mean reduction in CDAI, 211; range 102-367), 8 had clinical remission (53%; range, 43%-64%; mean CDAI at day 42, 94; range, 44-130). Seven patients had endoscopic improvement (47%), for whom the mean CDEIS scores decreased from 21.5 (range, 3.3-33) to 11.0 (range, 0.3-18.5). One patient had a serious adverse event (2 dysplasia-associated lesions), but this probably was not caused by MSCs. CONCLUSIONS: In a phase 2 study, administration of allogeneic MSCs reduced CDAI and CDEIS scores in patients with luminal CD refractory to biologic therapy. ClinicalTrials.gov number, NCT01090817.

Notch signaling promotes intestinal crypt fission in the infant rat.

BACKGROUND: Growth of the small intestine in the infant rat is promoted by crypt fission and later by increased crypt cell proliferation. Notch signaling could promote crypt fission. Hes-1 is a Notch target gene. AIM: We assessed the effect of Notch signaling on intestinal crypt fission and on growth of the intestine in the infant rat. METHODS: Hes-1 expression was determined in the small intestine of litters of Hooded Wistar rats aged between 3 and 72 days. Hes-1 RNA expression was measured by quantitative RT-PCR. Four groups of rats (n = 8 or 9) were injected daily, ip, either with vehicle or with the Notch inhibitor DAPT at doses of 3, 10, and 30 mg/kg, from days 9 to 13 of life, and killed on day 14. A microdissection technique was used to measure crypt fission, mitotic count, and apoptotic count. Data were analyzed by ANOVA and by use of Dunnett's F test. RESULTS: Hes-1 expression and crypt fission peaked on day 14. DAPT reduced Hes-1 immunostaining in proportion to dose. DAPT reduced villous area to 72 % (p < 0.01), 53 % (p < 0.001), and 38 % (p < 0.001) of control values for 3, 10 and 30 mg/kg doses, respectively, and reduced crypt fission to 53 % (p < 0.001) and 38 % (p < 0.001) of control values, respectively, for 10 and 30 mg/kg doses. Crypt mitotic count was not affected by any DAPT dose. DAPT at 10 and 30 mg/kg significantly increased apoptosis in crypts, by 6.5 and 4.8-fold, respectively. CONCLUSIONS: We conclude that Notch signaling promotes crypt fission and growth of the intestine by maintaining low apoptosis of crypt cells.

A simple, cost-effective and flexible method for processing of snap-frozen tissue to prepare large amounts of intact RNA using laser microdissection.

Understanding the molecular basis of disease requires gene expression profiling of normal and pathological tissue. Although the advent of laser microdissection (LMD) has greatly facilitated the procurement of specific cell populations, often only small amounts of low quality RNA is recovered. This precludes the use of global approaches of gene expression profiling which require sizable amounts of high quality RNA. Here we report a method for processing of snap-frozen tissue to prepare large amounts of intact RNA using LMD. Portions of small intestine from piglets (n = 6) were snap-frozen in Optimum Cutting Temperature compound (experimental) and in RNAlater (control). A randomly selected sample was laser microdissected using the developed protocol in multiple sessions totalling 4 h each day on four consecutive days. RNAs were extracted from these samples and its control and their quality (RIN) determined. RINs of the experimental samples were independent of time (p = 0.12) and day (p = 0.56) of the microdissection thereby suggesting that their RNA quality remained unaltered. These samples exhibited high quality (RIN ≥ 8) with good recovery (81.2%) and excellent yield (1539 ng/1.2 × 10(7) µm(2)). Their overall RIN, 8.029 ± 0.116, was not significantly different from 8.2 (p = 0.123), the value obtained from the control, non-laser microdissected, sample. This indicated that the RNA quality from the laser microdissected and non-microdissected samples was comparable. The method allowed LMD for up to 4 h each day for a total of four days. The microdissected samples can be pooled thereby increasing amount of RNA at least by ten-fold. The procedure did not require any expensive limited-shelf life RNase inhibitors, RNA protectors, staining kits or toxic chemicals. Furthermore, it was flexible and enabled the processing without affecting routine laboratory workflow. The method developed was simple, inexpensive and provided substantial amounts of high quality RNA suitable for gene expression profiling and other cellular and molecular analyses for biology and molecular medicine.

Probiotic factors partially prevent changes to caspases 3 and 7 activation and transepithelial electrical resistance in a model of 5-fluorouracil-induced epithelial cell damage.

The potential efficacy of a probiotic-based preventative strategy against intestinal mucositis has yet to be investigated in detail. We evaluated supernatants (SN) from Escherichia coli Nissle 1917 (EcN) and Lactobacillus rhamnosus GG (LGG) for their capacity to prevent 5-fluorouracil (5-FU)-induced damage to intestinal epithelial cells. A 5-day study was performed. IEC-6 cells were treated daily from days 0 to 3, with 1 mL of PBS (untreated control), de Man Rogosa Sharpe (MRS) broth, tryptone soy roth (TSB), LGG SN, or EcN SN. With the exception of the untreated control cells, all groups were treated with 5-FU (5 µM) for 24 h at day 3. Transepithelial electrical resistance (TEER) was determined on days 3, 4, and 5, while activation of caspases 3 and 7 was determined on days 4 and 5 to assess apoptosis. Pretreatment with LGG SN increased TEER (p < 0.05) compared to controls at day 3. 5-FU administration reduced TEER compared to untreated cells on days 4 and 5. Pretreatment with MRS, LGG SN, TSB, and EcN SN partially prevented the decrease in TEER induced by 5-FU on day 4, while EcN SN also improved TEER compared to its TSB vehicle control. These differences were also observed at day 5, along with significant improvements in TEER in cells treated with LGG and EcN SN compared to healthy controls. 5-FU increased caspase activity on days 4 and 5 compared to controls. At day 4, cells pretreated with MRS, TSB, LGG SN, or EcN SN all displayed reduced caspase activity compared to 5-FU controls, while both SN groups had significantly lower caspase activity than their respective vehicle controls. Caspase activity in cells pretreated with MRS, LGG SN, and EcN SN was also reduced at day 5, compared to 5-FU controls. We conclude that pretreatment with selected probiotic SN could prevent or inhibit enterocyte apoptosis and loss of intestinal barrier function induced by 5-FU, potentially forming the basis of a preventative treatment modality for mucositis.

Wnt blockade with dickkopf reduces intestinal crypt fission and intestinal growth in infant rats.

OBJECTIVES: Intestinal crypt fission peaks during infancy. In human and experimental familial polyposis coli, increased crypt fission is due to activation of Wnt/ß-catenin signalling, but the molecular basis of crypt fission during intestinal growth has not been examined. The aim of this project was to investigate whether crypt fission and intestinal growth are affected by experimental blockade of the Wnt/ß-catenin signalling pathway. METHODS: Hooded Wistar rats were given either the Wnt inhibitor, dickkopf (30 and 100 ng), daily or vehicle control intraperitoneally from days 11 to 15 and were killed at day 16. Intestinal morphometry was used to measure villous area, crypt area, percentage of crypt fission, and crypt mitotic count. Intestinal stem cells were assessed by expression of real time-polymerase chain reaction for Lgr5 (a stem cell marker), and the number of ß-catenin-expressing crypts by immunostaining was determined after 100-ng dickkopf treatment. RESULTS: Dickkopf at 30 and 100 ng/day reduced villous area to 71% (P = 0.013) and 29% (P < 0.0001), crypt area to 42% (P = 0.0026) and 30% (P = 0.0067), and crypt fission to 51% (P = 0.006) and 29% (P < 0.0001), respectively, of control values. Mitotic count per crypt did not change. Lgr5 RNA expression and the number of ß-catenin-expressing crypts decreased in dickkopf-treated animals. CONCLUSIONS: We conclude that intestinal crypt fission during infancy is mediated by Wnt signalling. It is possible that local treatment with Wnt agonists could be used to increase intestinal growth.

Emu oil increases colonic crypt depth in a rat model of ulcerative colitis.

BACKGROUND: Current treatments for the inflammatory bowel diseases, encompassing Crohn's disease and ulcerative colitis, are variably effective. Emu oil, extracted from emu fat, predominantly comprises fatty acids, with purported claims of anti-inflammatory properties. AIM: We evaluated emu oil for its potential to ameliorate dextran sulphate sodium (DSS)-induced colitis in rats. METHODS: Male Sprague-Dawley Rats were allocated to treatment groups (n = 8). Groups 1 and 2 consumed water and were gavaged (1 ml) daily with water (group 1) or emu oil (group 2) from days 0 to 10. Groups 3-6 ingested 2% DSS in the drinking water from days 5 to 10 and were gavaged from days 0 to 10 with water (group 3), 0.5 ml emu oil (group 4) or 1 ml emu oil (group 5). Group 6 received 1 ml emu oil after commencing DSS treatment (days 6-10). Disease activity index, metabolic parameters, (13)C-sucrose breath test, and histological colonic damage severity and crypt depth were assessed. RESULTS: Emu oil in DSS-treated rats reduced colonic damage severity compared to DSS-controls (up to threefold; P < 0.001). In DSS-treated rats, crypts in the proximal colon were lengthened by 0.5 ml emu oil (373 ± 18 µm), compared with DSS-controls (302 ± 8 µm); whilst in the distal colon (DSS control: 271 ± 17 µm), crypt depth was greater following 0.5 ml emu oil (352 ± 22 µm) and 1 ml emu oil (341 ± 9 µm) and also when emu oil was administered post-DSS commencement (Group 6: 409 ± 16 µm; P < 0.05). Emu oil did not significantly affect other parameters of colonic architecture. CONCLUSIONS: Emu oil improved tissue damage associated with colitis, suggesting its potential as a unique formulation to augment conventional treatment approaches for IBD.

Desmin expression in colorectal cancer stroma correlates with advanced stage disease and marks angiogenic microvessels.

INTRODUCTION: Biomarkers that improve stratification of colorectal cancer patients for adjuvant therapy versus resection alone, or that are predictive of response to therapeutic agents, have the potential to greatly improve patient selection for such therapies. The aim was to determine proteins differentially expressed within the malignant epithelial glands and closely associated stromal elements compared to matched normal mucosa, and to characterise the over-expression of one such protein as a potential biomarker. METHODS: Protein from laser microdissected tumor and normal mucosa was analysed by two dimensional difference gel electrophoresis (2D DIGE) and mass spectrometry to determine differentially over expressed tumor proteins. Tumor over-expression of one such protein, desmin, was quantified using immunofluorescence staining in a larger cohort. Dual staining for desmin and vimentin, or desmin and von Willebrand factor, was performed to determine the cell type of interest. RESULTS: Desmin expression was significantly increased between stage I and III tumors, (P < 0.0001), and stage II and III tumors, (P < 0.0001). Strong focal desmin expression was found in stroma directly adjacent to carcinomatous glands and microvessels. These cells showed co-localisation of desmin and vimentin in close association with cells expressing VWF, indicating they were pericytes. Significantly higher levels of desmin-positive pericytes were observed in late stage tumors, consistent with increased angiogenesis. CONCLUSION: Pericyte coverage of vasculature is a marker of vessel maturation, hence desmin expression may have use as a marker for microvessel maturation. Clinical trials will be needed to determine its use in identifying tumors that will be less responsive to anti-angiogenic therapy.

Cells, cytokines and inflammatory bowel disease: a clinical perspective.

Ulcerative colitis and Crohn's disease are chronic inflammatory disorders of the GI tract. Although the disorders can usually be distinguished on clinical and pathological criteria, there are similarities in natural history and response to therapy. The purpose of this article is to examine the inflammatory infiltrate in both disorders and the cytokine profiles in intestinal mucosa and peripheral blood. For both disorders, the predominant cells in inflamed mucosa are neutrophils and lymphocytes positive for CD4. There are also increases in the number of B cells, macrophages, dendritic cells, plasma cells, eosinophils and perhaps mast cells. Cytokine levels and cytokine expression are also similar for both disorders, with increases in TNF-α and IFN-γ consistent with a Th1 response. As inflammation occurs in a microbial environment, one possibility is that the nature of the inflammatory response is largely independent of initiating factors. One concept that might be useful is that of initiating cells and cytokines and effector cells and cytokines. Persuasive evidence exists for a defect in phagocytic cells in Crohn's disease, perhaps with the expansion of a subset of activated macrophages. There are also possible links to natural killer cells and changes in the regulation of IL-8 and perhaps IL-22. For ulcerative colitis, the cellular events are less clear, but natural killer T cells may be important as initiating cells, and there is some evidence for upregulation of cytokines involved in Th2 responses, including IL-4 and IL-13. For both disorders, proinflammatory cytokines include TNF-α, IL-12, IL-23, and perhaps IL-17 and IFN-γ. Research challenges include the identification, activation and function of subsets of inflammatory cells, as well as new ways to terminate the inflammatory response.

Evidence supporting the use of probiotics for the prevention and treatment of chemotherapy-induced intestinal mucositis.

Although chemotherapy remains the current best practice for the treatment of neoplasia, the severity of its associated side-effects continues to impact detrimentally on the quality of life. Mucositis can affect both the oral cavity and intestine, and represents one of the most common side-effects of chemotherapy. It is characterized by ulceration, inflammation, diarrhoea, and intense abdominal pain. Despite extensive research there remains no definitive therapy for mucositis. This may be due to the multiple factors which contribute to its pathogenesis, including up-regulation of pro-inflammatory cytokines, increased apoptosis of epithelial cells, alteration of the gastrointestinal microbiota, and damage to the epithelium. Although employed increasingly in other gastrointestinal disorders, probiotics are yet to be comprehensively investigated in the treatment or prevention of chemotherapy-induced mucositis. Probiotic-based therapies have been shown to exert beneficial effects, including modulation of the microbiota and inhibition of pro-inflammatory cytokines. This review outlines the current evidence supporting the use of probiotics in intestinal mucositis, and suggests further research directions for the future.

Fatty acids as potential adjunctive colorectal chemotherapeutic agents.

Fatty acids (FA) are bioactive molecules which have potential as adjunctive chemotherapeutic agents. FA are classified as short-, medium; or long-chain on the basis of the number of carbon atoms in the aliphatic chain and have been reported to induce apoptosis in vitro in a range of cancer cell types, including breast, tongue, cervix and colorectal. However, to date the chain length exerting optimal anti-neoplastic properties remains undefined. Short chain fatty acids, such as butyrate (C4:0), have induced high rates of in vitro apoptosis, presumably related to epigenetic modification, cell cycle arrest and activation of pro-apoptotic genes. Medium chain fatty acids have demonstrated in vivo and in vitro cytotoxic and anti-microbial properties; however, scant evidence currently exists on their anti-neoplastic potential. Longer unsaturated fatty acids (C16-24: ω3-9), including conjugated linoleic acid and eicosapentaenoic acid, also exhibit in vitro anti-proliferative actions, including induction of oxidative stress and modification of intracellular signalling pathways. Although incorporation of FA into CRC chemotherapy regimens is in its infancy, evidence is accumulating to allow identification of the FA chain length capable of exerting the most effective anti-neoplastic activity.

Probiotic factors partially improve parameters of 5-fluorouracil-induced intestinal mucositis in rats.

Certain live bacteria have demonstrated preliminary indications of efficacy for the treatment of chemotherapy-induced intestinal mucositis. However, probiotic derived supernatants (SN) have yet to be investigated in the mucositis setting. We evaluated SN from Escherichia coli Nissle 1917 (EcN) and Lactobacillus fermentum BR11 (BR11) for their capacity to decrease 5-Fluorouracil (5-FU)-induced damage in vivo. Female Dark Agouti rats were gavaged with 1 mL of either SN or vehicle daily (days 0-8) and intraperitoneally injected with 5-FU (150 mg/kg) on day 5 to induce mucositis. On day 9, animals were culled and intestinal tissues collected. Significantly lower histological damage scores were apparent in the jejunum of 5-FU treated rats receiving SN compared to 5-FU controls. Myeloperoxidase levels in the jejunum of 5-FU treated rats were increased in vehicle and BR11 SN treatments compared to untreated controls, whereas no significant increase was observed after EcN SN treatment. 5-FU treatment significantly reduced villus height and crypt depth in the jejunum compared to normal controls; however no significant reduction in these parameters was observed in 5-FU treated rats receiving either SN. We conclude that bacterial SN, especially EcN, partially protect the intestine from 5-FU mucositis. Further studies are required to define specific mechanisms by which SN exert their beneficial effects.

The role of capsule endoscopy in suspected celiac disease patients with positive celiac serology.

BACKGROUND: Endomysial antibody (EMA) and tissue transglutaminase (tTG) antibody testing is used to screen subjects with suspected celiac disease. However, the traditional gold standard for the diagnosis of celiac disease is histopathology of the small bowel. As villous atrophy may be patchy, duodenal biopsies could potentially miss the abnormalities. Capsule endoscopy can obtain images of the whole small intestine and may be useful in the early diagnosis of celiac disease. AIMS: To evaluate suspected celiac disease patients who have positive celiac serology and normal duodenal histology and to determine, with capsule endoscopy, whether these patients have any endoscopic markers of celiac disease. METHODS: Twenty-two subjects with positive celiac serology (EMA or tTG) were prospectively evaluated. Eight of the subjects had normal duodenal histology and 14 had duodenal histology consistent with celiac disease. All subjects underwent capsule endoscopy. Endoscopic markers of villous atrophy such as loss of mucosal folds, scalloping, mosaic pattern, and visible vessels were assessed. RESULTS: Eight subjects with normal duodenal histology had normal capsule endoscopy findings. In the 14 subjects with duodenal histology that was consistent with celiac disease, 13 had celiac disease changes seen at capsule endoscopy. One subject with normal capsule endoscopy findings showed Marsh IIIc on duodenal histology. Using duodenal histology as the gold standard, capsule endoscopy had a sensitivity of 93%, specificity of 100%, PPV of 100%, and NPV of 89% in recognizing villous atrophy. CONCLUSIONS: Capsule endoscopy is useful in the detection of villous abnormalities in untreated celiac disease. Patients with positive celiac serology (EMA or tTG) and normal duodenal histology are unlikely to have capsule endoscopy markers of villous atrophy.

Morphometric evaluation of duodenal biopsies in celiac disease.

OBJECTIVES: The Marsh classification is a semiquantitative method for the diagnosis and monitoring of changes in duodenal biopsies in celiac disease. We have explored the possibility that quantitative changes in villous area and crypt length (morphometry) may provide better information on changes in duodenal morphology, particularly after the introduction of a gluten-free diet. METHODS: We measured villous height, apical and basal villous widths, and crypt length in 57 adults with celiac disease and 83 control subjects. Villous area was calculated as a trapezoid approximation. Serial changes in villous area and crypt length were determined at regular intervals for up to 4 years after the introduction of a gluten-free diet. Morphometric changes were also correlated with Marsh grade, self-reported adherence to a gluten-free diet, and changes in celiac serology. RESULTS: The gluten-free diet resulted in a progressive increase in villous area and a progressive decrease in crypt length. Morphometric improvement reached a plateau after 6-12 months with mean villous area attaining a value approximately half that of control subjects. Morphometric data were more sensitive than Marsh grade. Improvement in morphometric indices was significantly associated with the disappearance of anti-endomysial IgA antibody but not with dietary compliance. CONCLUSIONS: Morphometry is a sensitive way to document changes in duodenal biopsies in celiac disease. In adults treated with a gluten-free diet, it is uncommon for villous area to return to values observed in control subjects, but morphometric improvement is associated with the disappearance of anti-endomysial IgA antibody.

Capsule endoscopy: a valuable tool in the follow-up of people with celiac disease on a gluten-free diet.

OBJECTIVES: Traditional celiac disease guidelines recommend follow-up endoscopy and duodenal biopsies at 6-12 months after commencing a gluten-free diet (GFD). However, histology may remain abnormal even 1-2 years later. We evaluated the role of capsule endoscopy in patients with celiac disease after treatment with a GFD. METHODS: Twelve adult patients with newly diagnosed celiac disease were prospectively enrolled. All patients had baseline symptom assessment, celiac serology (tissue transglutaminase antibody, tTG), and capsule endoscopy. Twelve months after commencing a GFD, patients underwent repeat symptom assessment, celiac serology, upper gastrointestinal endoscopy, and capsule endoscopy. RESULTS: At baseline, capsule endoscopy detected endoscopic markers of villous atrophy in the duodenum and extending to a variable distance along the small intestine. On the basis of small bowel transit time, the mean±s.e.m. percentage of small intestine with villous atrophy was 18.2±3.7%. After 12 months on a GFD, repeat capsule endoscopy demonstrated mucosal healing from a distal to proximal direction, and the percentage of small intestine with villous atrophy was significantly reduced to 3.4±1.2% (P=0.0014) and this correlated with improvement in the symptom score (correlation 0.69, P=0.01). There was a significant improvement in symptom score (5.2±1.0 vs. 1.7±0.4, P=0.0012) and reduction in immunoglobulin A-tTG levels (81.5±10.6 vs. 17.5±8.2, P=0.0005). However, 42% of subjects demonstrated persistent villous abnormality as assessed by duodenal histology. CONCLUSIONS: After 12 months on a GFD, patients with celiac disease demonstrate an improvement in symptoms, celiac serology, and the extent of disease as measured by capsule endoscopy. Mucosal healing occurs in a distal to proximal direction. The extent of mucosal healing correlates with improvement in symptoms. Duodenal histology does not reflect the healing that has occurred more distally.

Stem cell marker olfactomedin 4: critical appraisal of its characteristics and role in tumorigenesis.

Olfactomedin 4 (OLFM4), a member of the olfactomedin domain-containing proteins, is a glycoprotein with molecular weight of approximately 64 kDa. The protein is a "robust marker" of Lgr5+ stem cells and has been localised to mitochondria, nuclei and cell membranes. The bulk of OLFM4 exists in a polymeric form which is held together by disulfide bonds and carbohydrate interactions. Earlier studies revealed that the protein binds to lectins and cadherins, and facilitates cell-cell adhesion. Recent data demonstrated that the protein possesses several hallmarks of carcinogenesis. OLFM4 has also been purported to be an inducible resistance factor to apoptotic stimuli such as radiation and anticancer drugs. Here, we review its synonyms and classification, gene structure, protein structure, intracellular and tissue distribution, adhesive and antiapoptotic; mitotic; migratory and cell cycle regulatory characteristics. We also critically evaluate recent advances in understanding of the transcriptional regulation of OLFM4 and its upstream signalling pathways with special emphasis on carcinogenesis and outline future perspectives in the field.

Foxp3+ regulatory T cells, Th17 effector cells, and cytokine environment in inflammatory bowel disease.

BACKGROUND: Inflammatory bowel disease (IBD) is thought to result from an aberrant immune response. Inflammation in IBD may be caused by the loss of homeostasis between CD4+ CD25high Foxp3+ regulatory cells (Treg) and proinflammatory Th17 cells. The aim of this study was to investigate Treg and Th17 cells in the peripheral blood and intestinal mucosa of IBD patients and to assess the mucosal cytokine environment. METHODS: Treg and Th17 cells were measured in peripheral blood of 63 IBD patients and 28 controls by flow cytometry. Forkhead box p3 (Foxp3), interleukin (IL)-17a, IL-1beta, IL-6, IL-21, IL-23, and transforming growth factor (TGF)-beta mRNA were analyzed using real-time reverse transcription polymerase chain reaction in intestinal biopsies of 24 IBD and 18 control subjects. RESULTS: A decrease in Treg and increase in Th17 cells was observed in the peripheral blood of IBD patients. When measured in the same patient and expressed as a ratio, a significant decrease in Treg/Th17 ratio was observed in IBD. Elevated expression of Foxp3, IL-17a, IL-1beta, and IL-6 was observed in the mucosa of IBD patients, while TGF-beta was only elevated in ulcerative colitis. CONCLUSION: IBD is associated with a reduced ratio of Treg to Th17 cells in peripheral blood and is characterized by a proinflammatory cytokine microenvironment, which supports the continued generation of Th17 cells.

Maternal milk, but not formula, regulates the immune response to beta-lactoglobulin in allergy-prone rat pups.

Controversy exists regarding the timing of the introduction of allergic foods into the diet. We investigated the immune response of rat pups exposed to beta-lactoglobulin (BLG), one of the main allergenic proteins in cow milk. Brown Norway allergy-prone rats were allocated into groups: dam-reared and unchallenged (DR), DR challenged with BLG via gavage (11 mg/d), or rats fed via gastric cannula a formula containing BLG (11 mg/d). BLG was given from d 4 of life. Rats were killed at d 10, 14, or 21. Sera were assayed for total IgE, BLG-specific IgG1, and rat mucosal mast cell protease II (RMCPII; indicator of mucosal mast cell degranulation). Ileum was assessed for cytokine mRNA. Mesenteric lymph nodes (MLN) were assessed for forkhead boxP3 (Foxp3) and chemokine (C-C motif) receptor 7 (CCR7) expression by real-time PCR and immunostained for Foxp3(+) CD4(+) regulatory cells. Formula feeding compared with dam-rearing with or without oral BLG challenge resulted in significantly greater serum IgE, BLG-specific IgG1, RMCPII, and intestinal mast cells but reduced MLN Foxp3(+) cells, Foxp3, and CCR7 expression and ileal cytokines, interleukin (IL)-4, IL-10, and interferon-gamma (P < 0.05). Importantly, giving BLG in the presence of maternal milk resulted in an immune response profile similar to that of unchallenged DR rats but with greater Foxp3 and CCR7 mRNA expression and CD4(+) Foxp3(+) cells (P < 0.05). We conclude that introducing an allergenic food with breast milk reduces immunological indicators of an allergic response, whereas introduction during formula feeding generates an allergic response.

Prevalence of celiac disease in the Asia-Pacific region.

The development of sensitive and specific serological assays for celiac disease has led to a revision of the prevalence of this disease in many countries. In the Asia-Pacific region, prevalence has been determined in only a minority of countries but those with prevalence rates of 1:50-1:500 adults include Australia, Iran, Israel, New Zealand, Syria and Turkey. In contrast, celiac disease appears to be extremely rare in Japan and may be rare in China. In India, prevalence rates are high in the northern states but much lower in the southern states. In individual countries, important determinants of prevalence include the per capita consumption of wheat and the frequency of a specific human leukocyte antigen (HLA) type genetically defined as HLA-DQB1*02 (*0201 or *0202) and serologically defined as HLA-DQ2. These determinants predict low prevalence rates for celiac disease in the Pacific Islands, South-East Asia and eastern China but higher rates in countries west of India and China. There is also the potential for a rising incidence of celiac disease if traditional rice-based diets are replaced by Western-style diets with a higher content of wheat products.