Gut commensals suppress interleukin-2 production through microRNA-200/BCL11B and microRNA-200/ETS-1 axes in lamina propria leukocytes of murine large intestine.

The role of microRNAs (miRNAs) in how microbiota influence the host intestinal immune system is not fully understood. We compared the expression profiles of miRNAs and mRNAs in lamina propria leukocytes (LPL) in the large intestines of germ-free (GF) and specific pathogen-free (SPF) mice. Microarray analysis revealed different expression profiles of miRNAs and mRNAs between GF and SPF mice. Quantitative real time-PCR (qRT-PCR) showed that the level of miR-200 family members was significantly higher in SPF mice than in GF mice. In silico prediction followed by qRT-PCR suggested that Bcl11b, Ets1, Gbp7, Stat5b, and Zeb1 genes were downregulated by the miR-200 family. Western blotting revealed that the expression of BCL11B and ETS-1, but not ZEB1, in large intestinal LPL was significantly lower in SPF mice than in GF mice. Interleukin (IL)-2 production in cultured LPL upon stimulation with phorbol 12-myristate 13-acetate and ionomycin for 24 h was significantly lower in SPF mice than in GF mice. Conventionalization of GF mice substantially recapitulated SPF mice in terms of the expression of miR-200 family members and their target genes and IL-2 production in large intestinal LPL. Considering that BCL11B and ETS-1 reportedly function as transcription factors to activate the Il2 gene, we propose that the presence of gut commensals suppresses IL-2 production in large intestinal LPL, at least in part through post-transcriptional downregulation of Bcl11b and Ets1 genes by miR-200 family members.

Intestinal organoids in farm animals.

In livestock species, the monolayer of epithelial cells covering the digestive mucosa plays an essential role for nutrition and gut barrier function. However, research on farm animal intestinal epithelium has been hampered by the lack of appropriate in vitro models. Over the past decade, methods to culture livestock intestinal organoids have been developed in pig, bovine, rabbit, horse, sheep and chicken. Gut organoids from farm animals are obtained by seeding tissue-derived intestinal epithelial stem cells in a 3-dimensional culture environment reproducing in vitro the stem cell niche. These organoids can be generated rapidly within days and are formed by a monolayer of polarized epithelial cells containing the diverse differentiated epithelial progeny, recapitulating the original structure and function of the native epithelium. The phenotype of intestinal organoids is stable in long-term culture and reflects characteristics of the digestive segment of origin. Farm animal intestinal organoids can be amplified in vitro, cryopreserved and used for multiple experiments, allowing an efficient reduction of the use of live animals for experimentation. Most of the studies using livestock intestinal organoids were used to investigate host-microbe interactions at the epithelial surface, mainly focused on enteric infections with viruses, bacteria or parasites. Numerous other applications of farm animal intestinal organoids include studies on nutrient absorption, genome editing and bioactive compounds screening relevant for agricultural, veterinary and biomedical sciences. Further improvements of the methods used to culture intestinal organoids from farm animals are required to replicate more closely the intestinal tissue complexity, including the presence of non-epithelial cell types and of the gut microbiota. Harmonization of the methods used to culture livestock intestinal organoids will also be required to increase the reproducibility of the results obtained in these models. In this review, we summarize the methods used to generate and cryopreserve intestinal organoids in farm animals, present their phenotypes and discuss current and future applications of this innovative culture system of the digestive epithelium.

Distinct Age-Specific miRegulome Profiling of Isolated Small and Large Intestinal Epithelial Cells in Mice.

The intestinal epithelium serves as a dynamic barrier to protect the host tissue from exposure to a myriad of inflammatory stimuli in the luminal environment. Intestinal epithelial cells (IECs) encompass differentiated and specialized cell types that are equipped with regulatory genes, which allow for sensing of the luminal environment. Potential inflammatory cues can instruct IECs to undergo a diverse set of phenotypic alterations. Aging is a primary risk factor for a variety of diseases; it is now well-documented that aging itself reduces the barrier function and turnover of the intestinal epithelium, resulting in pathogen translocation and immune priming with increased systemic inflammation. In this study, we aimed to provide an effective epigenetic and regulatory outlook that examines age-associated alterations in the intestines through the profiling of microRNAs (miRNAs) on isolated mouse IECs. Our microarray analysis revealed that with aging, there is dysregulation of distinct clusters of miRNAs that was present to a greater degree in small IECs (22 miRNAs) compared to large IECs (three miRNAs). Further, miRNA-mRNA interaction network and pathway analyses indicated that aging differentially regulates key pathways between small IECs (e.g., toll-like receptor-related cascades) and large IECs (e.g., cell cycle, Notch signaling and small ubiquitin-related modifier pathway). Taken together, current findings suggest novel gene regulation pathways by epithelial miRNAs in aging within the gastrointestinal tissues.

Commensal microbiota-induced microRNA modulates intestinal epithelial permeability through the small GTPase ARF4.

The intestinal tract contains many commensal bacteria that modulate various physiological host functions. Dysbiosis of commensal bacteria triggers dysfunction of the intestinal epithelial barrier, leading to the induction or aggravation of intestinal inflammation. To elucidate whether microRNA plays a role in commensal microbiome-dependent intestinal epithelial barrier regulation, we compared transcripts in intestinal epithelial cells (IECs) from conventional and germ-free mice and found that commensal bacteria induced the expression of miR-21-5p in IECs. miR-21-5p increased intestinal epithelial permeability and up-regulated ADP ribosylation factor 4 (ARF4), a small GTPase, in the IEC line Caco-2. We also found that ARF4 expression was up-regulated upon suppression of phosphatase and tensin homolog (PTEN) and programmed cell death 4 (PDCD4), which are known miR-21-5p targets, by RNAi. Furthermore, ARF4 expression in epithelial cells of the large intestine was higher in conventional mice than in germ-free mice. ARF4 suppression in the IEC line increased the expression of tight junction proteins and decreased intestinal epithelial permeability. These results indicate that commensal microbiome-dependent miR-21-5p expression in IECs regulates intestinal epithelial permeability via ARF4, which may therefore represent a target for preventing or managing dysfunction of the intestinal epithelial barrier.

Distribution and characterisation of CCK containing enteroendocrine cells of the mouse small and large intestine.

There is general consensus that enteroendocrine cells, EEC, containing the enteric hormone cholecystokinin (CCK) are confined to the small intestine and predominate in the duodenum and jejunum. Contrary to this, EEC that express the gene for CCK have been isolated from the large intestine of the mouse and there is evidence for EEC that contain CCK-like immunoreactivity in the mouse colon. However, the human and rat colons do not contain CCK cells. In the current study, we use immunohistochemistry to investigate CCK peptide presence in endocrine cells, PCR to identify cck transcripts and chromatography to identify CCK peptide forms in the mouse small and large intestine. The colocalisation of CCK and 5-HT, hormones that have been hypothesised to derive from cells of different lineages, was also investigated. CCK immunoreactivity was found in EEC throughout the mouse small and large intestine but positive cells were rare in the rectum. Immunoreactive EEC were as common in the caecum and proximal colon as they were in the duodenum and jejunum. CCK gene transcripts were found in the mucosa throughout the intestine but mRNA for gastrin, a hormone that can bind some anti-CCK antibodies, was only found in the stomach and duodenum. Characterisation of CCK peptides of the colon by extraction, chromatographic separation and radioimmunoassay revealed bioactive amidated and sulphated forms, including CCK-8 and CCK-33. Moreover, CCK-containing EEC in the large intestine bound antibodies that target the biologically active sulfated form. Colocalisation of CCK and 5-HT occurred in a proportion of EEC throughout the small intestine and in the caecum but these hormones were not colocalised in the colon, where there was CCK and PYY colocalisation. It is concluded that authentic, biologically active, CCK occurs in EEC of the mouse large intestine.

Effect of deoxynivalenol on the levels of toll-like receptors 2 and 9 and their mRNA expression in enterocytes in the porcine large intestine: a preliminary study.

Deoxynivalenol (DON), one of the most prevalent mycotoxins in the world, and is capable of inducing immune disorders in humans and animals. The aim of this study was to determine the effect of feed contaminated with DON on the number of TLR2- and TLR9-positive cells and their mRNA expression in the porcine large intestine. The experiment was conducted on two equal groups of pigs (n=4). The experimental group (E) was administered feed contaminated with DON (1008 µg/kg of feed) for 6 weeks, and the control group (C) was administered non-contaminated feed over the same period of time. A decrease in the expression of TLR2 mRNA was noted in the cecum. The percentage of TLR9-positive enterocytes increased in the ascending colon and decreased in the cecum. The results of this study indicate that DON can modify the local immune response by changing the expression of TLRs.

Neural influences on human intestinal epithelium in vitro.

KEY POINTS: We present the first systematic and, up to now, most comprehensive evaluation of the basic features of epithelial functions, such as basal and nerve-evoked secretion, as well as tissue resistance, in over 2200 surgical specimens of human small and large intestine. We found no evidence for impaired nerve-evoked epithelial secretion or tissue resistance with age or disease pathologies (stomach, pancreas or colon cancer, polyps, diverticulitis, stoma reversal). This indicates the validity of future studies on epithelial secretion or resistance that are based on data from a variety of surgical specimens. ACh mainly mediated nerve-evoked and basal secretion in the small intestine, whereas vasoactive intestinal peptide and nitric oxide were the primary pro-secretory transmitters in the large intestine. The results of the present study revealed novel insights into regional differences in nerve-mediated secretion in the human intestine and comprise the basis by which to more specifically target impaired epithelial functions in the diseased gut. ABSTRACT: Knowledge on basic features of epithelial functions in the human intestine is scarce. We used Ussing chamber techniques to record basal tissue resistance (R-basal) and short circuit currents (ISC; secretion) under basal conditions (ISC-basal) and after electrical field stimulation (ISC-EFS) of nerves in 2221 resectates from 435 patients. ISC-EFS was TTX-sensitive and of comparable magnitude in the small and large intestine. ISC-EFS or R-basal were not influenced by the patients' age, sex or disease pathologies (cancer, polyps, diverticulitis). Ion substitution, bumetanide or adenylate cyclase inhibition studies suggested that ISC-EFS depended on epithelial cAMP-driven chloride and bicarbonate secretion but not on amiloride-sensitive sodium absorption. Although atropine-sensitive cholinergic components prevailed for ISC-EFS of the duodenum, jejunum and ileum, PG97-269-sensitive [vasoactive intestinal peptide (VIP) receptor 1 antagonist] VIPergic together with L-NAME-sensitive nitrergic components dominated the ISC-EFS in colonic preparations. Differences in numbers of cholinergic or VIPergic neurons, sensitivity of epithelial muscarinic or VIP receptors, or stimulus frequency-dependent transmitter release were not responsible for the region-specific transmitter contribution to ISC-EFS. Instead, the low atropine-sensitivity of ISC-EFS in the colon was the result of high cholinesterase activity because neostigmine revealed cholinergic components. Colonic ISC-EFS remained unchanged after tachykinin, P2X, P2Y or A1 and A2 receptor blockade. R-basal was smaller and ISC-basal was higher in the small intestine. TTX and bumetanide decreased ISC-basal in all regions, suggesting nerve-dependent secretory tone. ISC-basal was atropine-sensitive in the small intestine and PG97-269-sensitive in the large intestine. This comprehensive study reveals novel insights into region-specific nerve-mediated secretion in the human small and large intestine.

Identification of different functional types of spinal afferent neurons innervating the mouse large intestine using a novel CGRPα transgenic reporter mouse.

Spinal afferent neurons detect noxious and physiological stimuli in visceral organs. Five functional classes of afferent terminals have been extensively characterized in the colorectum, primarily from axonal recordings. Little is known about the corresponding somata of these classes of afferents, including their morphology, neurochemistry, and electrophysiology. To address this, we made intracellular recordings from somata in L6/S1 dorsal root ganglia and applied intraluminal colonic distensions. A transgenic calcitonin gene-related peptide-α (CGRPα)-mCherry reporter mouse, which enabled rapid identification of soma neurochemistry and morphology following electrophysiological recordings, was developed. Three distinct classes of low-threshold distension-sensitive colorectal afferent neurons were characterized; an additional group was distension-insensitive. Two of three low-threshold classes expressed CGRPα. One class expressing CGRPα discharged phasically, with inflections on the rising phase of their action potentials, at low frequencies, to both physiological (<30 mmHg) and noxious (>30 mmHg) distensions. The second class expressed CGRPα and discharged tonically, with smooth, briefer action potentials and significantly greater distension sensitivity than phasically firing neurons. A third class that lacked CGRPα generated the highest-frequency firing to distension and had smaller somata. Thus, CGRPα expression in colorectal afferents was associated with lower distension sensitivity and firing rates and larger somata, while colorectal afferents that generated the highest firing frequencies to distension had the smallest somata and lacked CGRPα. These data fill significant gaps in our understanding of the different classes of colorectal afferent somata that give rise to distinct functional classes of colorectal afferents. In healthy mice, the majority of sensory neurons that respond to colorectal distension are low-threshold, wide-dynamic-range afferents, encoding both physiological and noxious ranges.

Optimizing neurogenic potential of enteric neurospheres for treatment of neurointestinal diseases.

BACKGROUND: Enteric neurospheres derived from postnatal intestine represent a promising avenue for cell replacement therapy to treat Hirschsprung disease and other neurointestinal diseases. We describe a simple method to improve the neuronal yield of spontaneously formed gut-derived neurospheres. MATERIALS AND METHODS: Enteric neurospheres were formed from the small and large intestines of mouse and human subjects. Neurosphere size, neural crest cell content, cell migration, neuronal differentiation, and neuronal proliferation in culture were analyzed. The effect of supplemental neurotrophic factors, including glial cell line-derived neurotrophic factor (GDNF) and endothelin-3, was also assessed. RESULTS: Mouse small intestine-derived neurospheres contained significantly more P75-expressing neural crest-derived cells (49.9 ± 15.3% versus 21.6 ± 11.9%, P < 0.05) and gave rise to significantly more Tuj1-expressing neurons than colon-derived neurospheres (69.9 ± 8.6% versus 46.2 ± 15.6%, P < 0.05). A similar pattern was seen in neurospheres isolated from human small and large intestine (32.6 ± 17.5% versus 10.2 ± 8.2% neural crest cells, P < 0.05; 29.7 ± 16.4% versus 16.0 ± 13.5% enteric neurons, P < 0.05). The addition of GDNF to the culture media further improved the neurogenic potential of small intestinal neurospheres (75.9 ± 4.0% versus 67.8 ± 5.8%, P < 0.05) whereas endothelin-3 had no effect. CONCLUSIONS: Enteric neurospheres formed from small intestine and supplemented with GDNF yield an enriched population of neural crest-derived progenitor cells and give rise to a high density of enteric neurons.

The role of Hes genes in intestinal development, homeostasis and tumor formation.

Notch signaling regulates intestinal development, homeostasis and tumorigenesis, but its precise downstream mechanism remains largely unknown. Here we found that inactivation of the Notch effectors Hes1, Hes3 and Hes5, but not Hes1 alone, led to reduced cell proliferation, increased secretory cell formation and altered intestinal structures in adult mice. However, in Apc mutation-induced intestinal tumors, inactivation of Hes1 alone was sufficient for reducing tumor cell proliferation and inducing differentiation of tumor cells into all types of intestinal epithelial cells, but without affecting the homeostasis of normal crypts owing to genetic redundancy. These results indicated that Hes genes cooperatively regulate intestinal development and homeostasis and raised the possibility that Hes1 is a promising target to induce the differentiation of tumor cells.

Comprehensive characterization of protein 4.1 expression in epithelium of large intestine.

The protein 4.1 family consists of four members, 4.1R, 4.1N, 4.1B and 4.1G, each encoded by a distinct gene. All 4.1 mRNAs undergo extensive alternative splicing. Functionally, they usually serve as adapters that link actin-based cytoskeleton to plasma membrane proteins. It has been reported that 4.1 proteins are expressed in most animal cell types and tissues including epithelial cells and epithelial tissues. However, the expression of 4.1 proteins in large intestine has not been well characterized. In the present study, we performed RT-PCR, western blot and immunohistochemistry analysis to characterize the transcripts, the protein expression and cellular localization of 4.1 proteins in the epithelia of mouse large intestine. We show that multiple transcripts derive from each gene, including eight 4.1R isoforms, four 4.1N isoforms, four 4.1B isoforms and six 4.1G isoforms. However, at the protein level, only one or two major bands were detected, implying that not all transcripts are translated and/or the proteins do not accumulate at detectable levels. Immunohistochemistry revealed that 4.1R, 4.1N and 4.1B are all expressed at the lateral membrane as well as cytoplasm of epithelial cells, suggesting a potentially redundant role of these proteins. Our findings not only provide new insights into the structure of protein 4.1 genes but also lay the foundation for future functional studies.

Intestinal selenoprotein P in epithelial cells and in plasma cells.

The micronutrient selenium and selenium-containing selenoproteins are involved in prevention of inflammation and carcinogenesis in the gut. Selenoprotein P (Sepp1), the plasma selenium transport protein, is secreted primarily from hepatocytes, but Sepp1 mRNA is also abundant in the intestine. By immunofluorescence analysis, we show that Sepp1 levels in epithelial cells of the rat jejunum increase along the crypt-to-villus axis. A different Sepp1 distribution pattern was observed in the rat colon, where the epithelial cells located at the base and at the top of the crypts were similarly positive for Sepp1. In addition, we found pronounced Sepp1 immunoreactivity in CD138-positive plasma cells scattered within the lamina propria of the colon. This hitherto unrecognized presence in terminally differentiated B-cells was corroborated by detection of Sepp1 in plasma cells residing in the rat spleen. Following supplementation with dietary selenium compounds, polarized intestinal epithelial Caco-2 cells secreted Sepp1 into the culture medium across the basolateral membrane. Our data suggest that Sepp1 secreted from epithelial cells may support the intestinal immune system by providing immune cells (including plasma cells) with selenium for the biosynthesis of endogenous selenoproteins.

Design of endoscopic micro-robotic end effectors: safety and performance evaluation based on physical intestinal tissue damage characteristics.

During the last several years, legged locomotive mechanism has been considered as one of the main self-propelling mechanisms for future endoscopic microrobots due to its superior propulsion efficiency of an endoscopic microrobot inside the intestinal track. Nevertheless, its clinical application has been largely limited since the legged locomotive mechanism utilizes an end effector which has a sharp tip to generate sufficient traction by physically penetrating and interlocking with the intestinal tissue. This can cause excessive physical tissue damage or even complete perforation of the intestinal wall that can lead to abdominal inflammation. Hence, in this work two types of new end effectors, penetration-limited end effector (PLEE) and bi-material structured end effector (BMEE) were specially designed to acquire high medical safety as well as effective traction generation performance. The microscopic end effector specimens were fabricated with micro-wire electric discharge machining process. Traction generation performance of the end effectors was evaluated by direct measurement of resistance forces during contact-sliding tests using a custom-built contact-sliding tester. The safety of the end effector design was evaluated by examination of microscopic intestinal tissue damage using a scanning electron microscope (SEM). Physical damage characteristics of the intestinal tissue and related contact physics of the end effectors were discussed. From the results, the end effectors were evaluated with respect to their prospects in future medical applications as safe end effectors as well as micro-surgical tools.

The endoplasmic reticulum stress transducer OASIS is involved in the terminal differentiation of goblet cells in the large intestine.

OASIS is a basic leucine zipper transmembrane transcription factor localized in the endoplasmic reticulum (ER) that is cleaved in its transmembrane region in response to ER stress. This novel ER stress transducer has been demonstrated to express in osteoblasts and astrocytes and promote terminal maturation of these cells. Additionally, OASIS is highly expressed in goblet cells of the large intestine. In this study, we investigated the roles of OASIS in goblet cell differentiation in the large intestine. To analyze the functions of OASIS in goblet cells, we examined morphological changes and the expression of goblet cell differentiation markers in the large intestine of Oasis(-/-) mice. By disrupting the Oasis gene, the number of goblet cells and production of mucus were decreased in the large intestine. Oasis(-/-) goblet cells showed abnormal morphology of mucous vesicles and rough ER. The expression levels of mature goblet cell markers were lower, and conversely those of early goblet cell markers were higher in Oasis(-/-) mice, indicating that differentiation from early to mature goblet cells is impaired in Oasis(-/-) mice. To determine the association of OASIS with other factors involved in goblet cell differentiation, in vitro experiments using a cell culture model were performed. We found that OASIS was activated in response to mild ER stress that is induced in differentiating goblet cells. Knockdown of the Oasis transcript perturbed goblet cell terminal differentiation. Together, our data indicate that OASIS plays crucial roles in promoting the differentiation of early goblet cells to mature goblet cells in the large intestine.

Changes in plasma levels of serotonin and 5-hydroxyindoleacetic acid and population of serotonin-secreting cells in small and large intestine of Wistar rats in hypo- and hyperandrogenemia.

We studied the effects of hypo- and hyperandrogenemia on the plasma levels of serotonin and its major metabolite 5-hydroxyindoleacetic acid as well as on the size of EC1 cell pool in the small and large intestine of adult male Wistar rats in the control group, after orchiectomy, and after administration of long-acting testosterone Omnadren 250. Orchiectomy did not change the levels of serotonin, 5-hydroxyindoleacetic acid, and the number of AN-1-cells in the epithelium of the small and large intestine. Administration of Omnadren 250 increased serum level of free testosterone and reduced plasma serotonin concentration; the level of 5-hydroxyindoleacetic acid remained unchanged and hence the rate of serotonin metabolism increased. Hyperandrogenemia significantly reduced the number of AN-1- in the jejunum and ileum and did not change this parameter in the duodenum and colon.

The small and large intestine contain related mesenchymal subsets that derive from embryonic Gli1+ precursors.

The intestinal lamina propria contains a diverse network of fibroblasts that provide key support functions to cells within their local environment. Despite this, our understanding of the diversity, location and ontogeny of fibroblasts within and along the length of the intestine remains incomplete. Here we show that the small and large intestinal lamina propria contain similar fibroblast subsets that locate in specific anatomical niches. Nevertheless, we find that the transcriptional profile of similar fibroblast subsets differs markedly between the small intestine and colon suggesting region specific functions. We perform in vivo transplantation and lineage-tracing experiments to demonstrate that adult intestinal fibroblast subsets, smooth muscle cells and pericytes derive from Gli1-expressing precursors present in embryonic day 12.5 intestine. Trajectory analysis of single cell RNA-seq datasets of E12.5 and adult mesenchymal cells suggest that adult smooth muscle cells and fibroblasts derive from distinct embryonic intermediates and that adult fibroblast subsets develop in a linear trajectory from CD81+ fibroblasts. Finally, we provide evidence that colonic subepithelial PDGFRαhi fibroblasts comprise several functionally distinct populations that originate from an Fgfr2-expressing fibroblast intermediate. Our results provide insights into intestinal stromal cell diversity, location, function, and ontogeny, with implications for intestinal development and homeostasis.

Pharmacological differences of endothelin receptors-mediated modulation in cultured interstitial cells of Cajal from the murine small and large intestine.

Interstitial cells of Cajal (ICCs) are pacemaker cells that activate the periodic spontaneous depolarization (pacemaker potentials) responsible for the production of slow waves in gastrointestinal smooth muscle. Under current clamping, ICCs had a mean resting membrane potential of -58 ± 3 mV and externally applied ET produced membrane depolarization in a dosedependent manner. These effects were reduced by intracellular GDP beta S. A comparison of the concentration-dependent membrane depolarizations on pacemaker potentials to ET-1, ET-2 and ET-3 showed a rank order of potency ET-1≥ET-2≥ET-3 in cultured murine small intestinal ICCs. The pretreatment with Ca(2+)-free solution and thapsigargin, a Ca(2+)-ATPase inhibitor in endoplasmic reticulum, abolished the generation of pacemaker potentials and suppressed the ET-1 induced membrane depolarizations. Chelerythrine and calphostin C, protein kinase C inhibitors or naproxen, an inhibitor of cyclooxygenase, did not block the ET-1 induced effects on pacemaker potentials. Pretreatment with BQ-123 (ET(A )receptor antagonist) or BQ-788 (ET(B )receptor antagonist) blocked the ET-1 induced effects on pacemaker potentials in cultured murine small intestinal ICCs. However, pretreatment with BQ-788 selectively did not block the ET-1 induced effects on pacemaker potentials in cultured murine large intestinal ICCs. Also, only externally applied selective ET(B )receptor agonist, IRL 1620 did not show any influence on pacemaker potentials in cultured murine large intestine ICCs. RT-PCR results indicated the presence of the ET(A )and ET(B )receptor in ICCs. These results suggested that ET-1 modulates pacemaker potentials through ET(A )and ET(B )receptor activation in murine small intestinal ICCs and ET(A )receptor activation in murine large intestinal ICCs by external Ca(2+) influx and internal Ca(2+) release via protein kinase C or cyclooxygenase-independent mechanism. Therefore, the ICCs are targets for ET and their interaction can affect intestinal motility.

Protective and restorative effects of sophorolipid on intestinal dystrophy in dextran sulfate sodium-induced colitis mouse model.

The public has gradually begun to regard inflammatory bowel disease (IBD) as a crucial health issue; however, its mode of action has not been fully elucidated. Sophorolipid (SPL), a glycolipid-type biosurfactant, could be used as a potential treatment in physical intestinal dystrophy. We conducted a 2 × 2 factorial experiment to investigate the protective effect of SPL in a dextran sulfate sodium (DSS)-induced colitis mouse model (first factor, presence of SPL in feed; second factor, presence of DSS in water). Forty C57BL/6 mice (8-week-old) were used, and they were allocated to treatments according to their initial body weight. After a 7 d adjustment period, the DSS treatment was initiated in specific groups. At day 14, DSS was withdrawn from mice, and half of the mice were randomly selected and euthanized to collect colon and colon content samples. Three days after the end of DSS treatment, the rest of the mice were euthanized to investigate the therapeutic effect of SPL. Dietary SPL improved the growth performance in 3 d after DSS treatment, and the histopathological score was lower in the DSS-treated SPL group than in the DSS-treated control group. Mucosal thickness and goblet cell numbers significantly increased in the SPL-supplemented groups compared to in the control group. Similarly, SPL supplementation upregulated the gene expression levels of mucin-2, interleukin-10, and transforming growth factor-ß, and increased the concentration of short chain fatty acid compared to the control groups. In conclusion, dietary supplementation with SPL attenuated the pathological response against acute and chronic inflammation by the maintenance of the mucosal barrier and wound healing capacity.

Rapid dendritic cell mobilization to the large intestinal epithelium is associated with resistance to Trichuris muris infection.

The large intestine is a major site of infection and disease, yet little is known about how immunity is initiated within this site and the role of dendritic cells (DCs) in this process. We used the well-established model of Trichuris muris infection to investigate the innate response of colonic DCs in mice that are inherently resistant or susceptible to infection. One day postinfection, there was a significant increase in the number of immature colonic DCs in resistant but not susceptible mice. This increase was sustained at day 7 postinfection in resistant mice when the majority of the DCs were mature. There was no increase in DC numbers in susceptible mice until day 13 postinfection. In resistant mice, most colonic DCs were located in or adjacent to the epithelium postinfection. There were also marked differences in the expression of colonic epithelial chemokines in resistant mice and susceptible mice. Resistant mice had significantly increased levels of epithelium-derived CCL2, CCL3, CCL5, and CCL20 compared with susceptible mice. Furthermore, administering neutralizing CCL5 and CCL20 Abs to resistant mice prevented DC recruitment. This study provides clear evidence of differences in the kinetics of DC responses in hosts inherently resistant and susceptible to infection. DC responses in the colon correlate with resistance to infection. Differences in the production of DC chemotactic chemokines by colonic epithelial cells in response to infection in resistant vs susceptible mice may explain the different kinetics of the DC response.

Henoch-Schönlein purpura complicated by appendicitis, intussusception and ureteritis.

Henoch-Schönlein purpura (HSP) is the most common childhood systemic small-vessel vasculitis with skin, joint, gastrointestinal (GI) and renal involvement. Uncommon GI complications are intussusception, bowel perforation and rarely reported appendicitis. HSP-associated stenosing ureteritis represents a rare and potentially serious complication. We present a 5-year-old boy with severe and prolonged course of HSP and three very rare complications that occurred sequentially: appendicitis, intussusception and ureteritis. Only three days after admission, he developed clinical signs of acute appendicitis indicating surgical intervention. Histological analysis of excised appendix showed inflammation but without signs typical for vasculitis. Two weeks later, with the reccurence of HSP he again developed clinical picture of acute abdomen. Ultrasound and radiologic evaluation demonstrated ileo-ileal intussusception and the second laparotomy was undertaken. Histological analysis of the resected bowel tissue showed typical signs of leucocytoclastic vasculitis. In the fourth week of his illness, serial urinalysis showed nephritic urinary sediment indicative of renal involvement. Unexpectedly, control abdominal ultrasound demonstrated mild hydronephrosis of the left kidney, not seen on previous ultrasound evaluations. Undertaken excretory urography and computed tomography (CT) scan showed stenosis of upper/ midureter with mild dilation of upper part of the left ureter suggesting unilateral HSP-associated stenosing ureteritis. Eventually, the patient was discharged and closely followed-up for the next two years. He had no further reccurence of HSP, the urinalysis normalized after six months, while mild unilateral hydronephrosis remained unchanged. Our search of the literature did not show reports of HSP complicated by appendicitis, intussusception and ureteritis, and to our knowledge this is the first case with three different illness events that occured sequentially. We emphasize the necessity of repeated ultrasound evaluations in the course of HSR especially in cases with severe GI and renal invovement.