Necrotizing enterocolitis (NEC) is an intestinal inflammatory and necrotic disease seen in premature infants, and remains the leading cause of death resulted from gastrointestinal diseases in premature infants. The specific pathogenesis of NEC is still unclear. In recent years, a lot of studies have reported that Toll-like receptor 4 (TLR4) plays a key role in the pathogenesis of NEC. TLR4, which is abundantly expressed in intestinal epithelial cells of premature infants, binds to bacterial lipopolysaccharide (LPS) to activate downstream signaling pathways, leading to disruption of intestinal epithelial integrity and bacterial translocation, resulting in intestinal ischemic necrosis and inflammatory responses, which may rapidly progress to severe sepsis, multiple organ dysfunction, and death. This paper reviews the mechanism of TLR4-related signaling pathways in intestinal epithelial injury and inflammatory responses in newborns with NEC, providing a reference to study new therapeutic targets for NEC.
Enterocolitis, Necrotizing/pathology* ; Toll-Like Receptor 4/metabolism* ; Humans ; Infant, Newborn ; Signal Transduction ; Inflammation/metabolism* ; Animals ; Intestines/immunology* ; Intestinal Mucosa/pathology* ; Infant, Premature

OBJECTIVETo observe the effects of astragalus polysaccharide (AP) on the intestinal mucosal morphology, level of secretory IgA (s-IgA) in intestinal mucus, and distribution of T lymphocyte subsets in Peyer's patch in rats with severe scald injury.

METHODSOne hundred and thirty SD rats were divided into sham injury group (SI, sham injured, n = 10), scald group (S, n = 30), low dosage group (LD, n = 30), moderate dosage group (MD, n = 30), and high dosage group (HD, n = 30) according to the random number table. Rats in the latter 4 groups were inflicted with 30% TBSA full-thickness scald on the back. From post injury hour 2, rats in groups LD, MD, and HD were intraperitoneally injected with 0.5 mL AP solution with the dosage of 100, 200, and 300 mg/kg each day respectively, and rats in group S were injected with 0.5 mL normal saline instead. Ten rats from group SI immediately after injury and 10 rats from each of the latter 4 groups on post injury day (PID) 3, 7, 14 were sacrificed, and their intestines were harvested. The morphology of ileal mucosa was examined after HE staining; the level of s-IgA in ileal mucus was determined with double-antibody sandwich ELISA method; the proportions of CD3⁺, CD4⁺, CD8⁺ T lymphocytes in Peyer's patches of intestine were determined with flow cytometer, and the proportion of CD4⁺ to CD8⁺ was calculated. Data were processed with one-way analysis of variance, analysis of variance of factorial design, and SNK test.

RESULTS(1) Villi in normal form and intact villus epithelial cells were observed in rats of group SI immediately after injury, while edema of villi and necrosis and desquamation of an enormous amount of villi were observed in groups with scalded rats on PID 3, with significant infiltration of inflammatory cells. On PID 7, no obvious improvement in intestinal mucosal lesion was observed in groups with scalded rats. On PID 14, the pathology in intestinal mucosa of rats remained nearly the same in group S, and it was alleviated obviously in groups LD and MD, and the morphology of intestinal mucosa of rats in group HD was recovered to that of group SI. (2) On PID 3, 7, and 14, the level of s-IgA in intestinal mucus significantly decreased in groups S, LD, MD, and HD [(43 ± 5), (45 ± 5), (46 ± 5) µg/mL; (47 ± 5), (48 ± 5), (49 ± 6) µg/mL; (50 ± 6), (51 ± 5), (52 ± 5) µg/mL; (53 ± 6), (54 ± 5), (55 ± 5) µg/mL] as compared with that of rats in group SI immediately after injury [(69 ± 4) µg/mL, with P values below 0.05]. The level of s-IgA in intestinal mucus of rats in group MD was significantly higher than that in group S at each time point (with P values below 0.05), and that of group HD was significantly higher than that in groups S and LD at each time point (with P values below 0.05). (3) Compared with those of rats in group SI immediately after injury, the proportions of CD3⁺ T lymphocytes and CD4⁺ T lymphocytes significantly decreased in groups with scalded rats at each time point (with P values below 0.05), except for those in group HD on PID 14. The proportion of CD4⁺ T lymphocytes of rats in group LD was significantly higher than that in group S on PID 3 (P < 0.05). The proportions of CD3⁺ T lymphocytes and CD4⁺ T lymphocytes were significantly higher in groups MD and HD than in groups S and LD (except for the proportion of CD4⁺ T lymphocytes in group MD on PID 3 and 14) at each time point (with P values below 0.05). The proportion of CD3⁺ T lymphocytes on PID 7 and 14 and that of CD4⁺ T lymphocytes on PID 3 were significantly higher in group HD than in group MD (with P values below 0.05). Compared with that of rats in group SI immediately after injury, the proportion of CD8⁺ T lymphocytes significantly increased in the other 4 groups at each time point (with P values below 0.05). The proportion of CD8⁺ T lymphocytes was significantly lower in rats of group LD on PID 7 and 14 and groups MD and HD at each time point than in group S (with P values below 0.05). The proportion of CD8⁺ T lymphocytes was significantly lower in rats of group MD on PID 7 and 14 and group HD at each time point than in group LD (with P values below 0.05). The proportion of CD8⁺ T lymphocytes was significantly lower in rats of group HD on PID 7 and 14 than in group MD (with P values below 0.05). On PID 3, 7, and 14, the proportion of CD4⁺ to CD8⁺ was significantly lower in groups S, LD, MD, and HD (0.65 ± 0.11, 0.68 ± 0.13, 0.73 ± 0.22; 0.76 ± 0.15, 0.78 ± 0.14, 0.90 ± 0.10; 0.85 ± 0.21, 0.89 ± 0.18, 1.08 ± 0.19; 0.99 ± 0.20, 1.05 ± 0.21, 1.25 ± 0.23) as compared with that of rats in group SI immediately after injury (1.74 ± 0.20, with P values below 0.05). The proportion of CD4⁺ to CD8⁺ was significantly higher in rats of group HD than in group MD on PID 7 (P < 0.05), and the proportion was significantly higher in these two groups than in group S at each time point (with P values below 0.05). The proportion of CD4⁺ to CD8⁺ was significantly higher in rats of group MD on PID 14 and group HD at each time point than in group LD (with P values below 0.05). Compared within each group, the proportions of CD3⁺, CD4⁺, CD8⁺ T lymphocytes and the proportion of CD4⁺ to CD8⁺ of rats in groups LD, MD, and HD showed a trend of gradual elevation along with passage of time.

CONCLUSIONSAP can improve the injury to intestinal mucosa and modulate the balance of T lymphocyte subsets in Peyer's patch in a time- and dose-dependent manner, and it can promote s-IgA secretion of intestinal mucosa in a dose-dependent manner.

Animals ; Astragalus Plant ; adverse effects ; Burns ; immunology ; pathology ; physiopathology ; Dose-Response Relationship, Drug ; Immunity, Mucosal ; Immunoglobulin A ; metabolism ; Intestinal Mucosa ; metabolism ; physiology ; Intestine, Small ; metabolism ; Peyer's Patches ; immunology ; physiopathology ; Polysaccharides ; Rats ; Rats, Sprague-Dawley ; Soft Tissue Injuries ; T-Lymphocyte Subsets ; immunology

Inflammatory bowel disease (IBD) is a chronic progressive idiopathic inflammatory disorder that involves the digestive tract from the mouth to the anus. Over the past decades, many therapeutic strategies have been developed to manage IBD, but therapeutic strategies based only on relief of clinical symptoms have not changed the natural history of this disease entity. This underlines the importance of understanding the natural history of IBD itself. When we look at the natural history of Crohn's disease (CD), it first begins with inflammation of the intestinal mucosa and this inflammatory reaction proceeds to stenosing or penetrating reaction if not adequately controlled. However, it takes a considerable amount of time before mucosal inflammation proceeds to stenosis of the intestinal lumen or penetration into the adjacent bowel. Therefore, it can be expected that if proper care is given during that period, progression of CD to such a complicated disease could be prevented. Even though the concept of mucosal healing was introduced in the early 1990s, no correlation could be observed between healing of mucosal lesions and relief of clinical symptoms. However, the introduction of biologic agents targeting tumor necrosis factor has changed the way to treat IBD that is refractory to standard medications and has allowed us to aim for a new therapeutic goal, 'deep remission'. Further advances in biologic agents have provided highly effective treatments for IBD, making deep remission a realistic goal. Whether IBD patients may benefit by experiencing a 'deep' remission beyond the control of clinical symptoms need to be evaluated in further investigation. Nevertheless, it can be anticipated that attaining deep remission might ultimately have an impact on important outcomes such as the need for surgery and the quality of life.
Anti-Inflammatory Agents, Non-Steroidal/therapeutic use ; Antibodies, Monoclonal/therapeutic use ; Colitis, Ulcerative/drug therapy/metabolism/pathology ; Crohn Disease/drug therapy/metabolism/pathology ; Humans ; Inflammatory Bowel Diseases/drug therapy/metabolism/*pathology ; Intestinal Mucosa/metabolism/pathology ; Mesalamine/therapeutic use ; Tumor Necrosis Factor-alpha/immunology/metabolism

Abnormal levels of microRNA (miR)-155, which regulate inflammation and immune responses, have been demonstrated in the colonic mucosa of patients with inflammatory bowel diseases (IBD), although its role in disease pathophysiology is unknown. We investigated the role of miR-155 in the acquisition and maintenance of an activated phenotype by intestinal myofibroblasts (IMF), a key cell population contributing to mucosal damage in IBD. IMF were isolated from colonic biopsies of healthy controls, ulcerative colitis (UC) and Crohn's disease (CD) patients. MiR-155 in IMF was quantified by quantitative reverse transcription-PCR in basal condition and following exposure to TNF-alpha, interleukin (IL)-1beta, lipopolysaccharide (LPS) or TGF-beta1. The effects of miR-155 mimic or inhibitor transfection on cytokine release and suppressor of cytokine signaling 1 (SOCS1) expression were assessed by enzyme-linked immunosorbent assay and western blot, respectively. Regulation of the target gene SOCS1 expression by miR-155 was assessed using luciferase reporter construct. We found that miR-155 was significantly upregulated in UC as compared with control- and CD-derived IMF. Moreover, TNF-alpha and LPS, but not TGF-beta1 and IL-1beta, significantly increased miR-155 expression in IMF. Ectopic expression of miR-155 in control IMF augmented cytokines release, whereas it downregulated SOCS1 expression. MiR-155 knockdown in UC-IMF reduced cytokine production and enhanced SOCS1 expression. Luciferase reporter assay demonstrated that miR-155 directly targets SOCS1. Moreover, silencing of SOCS1 in control IMF significantly increased IL-6 and IL-8 release. In all, our data suggest that inflammatory mediators induce miR-155 expression in IMF of patients with UC. By downregulating the expression of SOCS1, miR-155 wires IMF inflammatory phenotype.
Adult ; Aged ; Cells, Cultured ; Colitis, Ulcerative/*genetics/immunology/*pathology ; Cytokines/immunology ; Female ; *Gene Expression Regulation ; Humans ; Intestinal Mucosa/immunology/metabolism/pathology ; Male ; MicroRNAs/*genetics ; Middle Aged ; Myofibroblasts/immunology/metabolism/*pathology ; Suppressor of Cytokine Signaling Proteins/*genetics ; Tumor Necrosis Factor-alpha/immunology ; Up-Regulation ; Young Adult

Abnormal levels of microRNA (miR)-155, which regulate inflammation and immune responses, have been demonstrated in the colonic mucosa of patients with inflammatory bowel diseases (IBD), although its role in disease pathophysiology is unknown. We investigated the role of miR-155 in the acquisition and maintenance of an activated phenotype by intestinal myofibroblasts (IMF), a key cell population contributing to mucosal damage in IBD. IMF were isolated from colonic biopsies of healthy controls, ulcerative colitis (UC) and Crohn's disease (CD) patients. MiR-155 in IMF was quantified by quantitative reverse transcription-PCR in basal condition and following exposure to TNF-alpha, interleukin (IL)-1beta, lipopolysaccharide (LPS) or TGF-beta1. The effects of miR-155 mimic or inhibitor transfection on cytokine release and suppressor of cytokine signaling 1 (SOCS1) expression were assessed by enzyme-linked immunosorbent assay and western blot, respectively. Regulation of the target gene SOCS1 expression by miR-155 was assessed using luciferase reporter construct. We found that miR-155 was significantly upregulated in UC as compared with control- and CD-derived IMF. Moreover, TNF-alpha and LPS, but not TGF-beta1 and IL-1beta, significantly increased miR-155 expression in IMF. Ectopic expression of miR-155 in control IMF augmented cytokines release, whereas it downregulated SOCS1 expression. MiR-155 knockdown in UC-IMF reduced cytokine production and enhanced SOCS1 expression. Luciferase reporter assay demonstrated that miR-155 directly targets SOCS1. Moreover, silencing of SOCS1 in control IMF significantly increased IL-6 and IL-8 release. In all, our data suggest that inflammatory mediators induce miR-155 expression in IMF of patients with UC. By downregulating the expression of SOCS1, miR-155 wires IMF inflammatory phenotype.
Adult ; Aged ; Cells, Cultured ; Colitis, Ulcerative/*genetics/immunology/*pathology ; Cytokines/immunology ; Female ; *Gene Expression Regulation ; Humans ; Intestinal Mucosa/immunology/metabolism/pathology ; Male ; MicroRNAs/*genetics ; Middle Aged ; Myofibroblasts/immunology/metabolism/*pathology ; Suppressor of Cytokine Signaling Proteins/*genetics ; Tumor Necrosis Factor-alpha/immunology ; Up-Regulation ; Young Adult

Light chain deposition disease (LCDD) is a rare disorder associated with a clonal proliferation of plasma cells, which synthesize abnormal monoclonal immunoglobulin light chains. LCDD is characterized by systemic deposition of light chains in various organs, with the kidneys being most commonly affected. There have been few reports of isolated LCDD. We report a rare case of LCDD limited to a duodenal polyp. A 63-yr-old man visited our hospital for health screening without symptoms in 2009. On gastrofiberscopy, a duodenal polyp was observed. The biopsy showed diffuse infiltration by atypical plasma cells, which were positive for kappa-type light chains by immunohistochemistry. While the patient refused further management, we could find no evidence of recurrence until 2 yr after the initial diagnosis. It has been reported that isolated LCDD has relatively good prognosis compared to systemic LCDD. However, treatment for this disease has not been established yet.
Duodenum/pathology ; Endoscopy, Gastrointestinal ; Humans ; Immunoglobulin kappa-Chains/*immunology/metabolism ; Immunohistochemistry ; Intestinal Mucosa/*pathology ; Male ; Middle Aged ; Paraproteinemias/*diagnosis/pathology ; Tomography, X-Ray Computed

Bacterial Translocation ; physiology ; Humans ; Intestinal Mucosa ; pathology ; physiology ; Lipopolysaccharides ; metabolism ; physiology ; Liver Failure, Acute ; etiology ; immunology ; physiopathology ; Lymphocytes ; immunology ; metabolism ; Macrophages ; immunology ; metabolism ; Signal Transduction ; genetics ; physiology ; Toll-Like Receptor 4 ; metabolism ; physiology

Intestinal mucosal layers are colonized by a complex microbiota that provides beneficial effects under normal physiological conditions, but is capable of contributing to chronic inflammatory disease such as inflammatory bowel disease (IBD) in susceptible individuals. Studies have shown that the enteric microbiota may drive the development of the gut immune system and can induce immune homeostasis as well as contribute to the development of IBD although the precise etiology is still unknown. Therefore, intestinal microbes seem to play a key role in the disease pathogenesis. Especially, dysbiosis, which is a shift in the composition of enteric microbiota to a nonphysiologic composition, is associated with one or more defects in mucosal immune functions, including microbe recognition, barrier function, intercellular communication, and anti-microbial effector mechanisms. This review focuses on the impact of enteric microbiota on the development and perpetuation of IBD. In addition, interactions with enteric bacteria and mucosal cells, including intestinal epithelial cells, dendritic cells, and T cells, to induce immune responses at mucosal surfaces have been discussed in the point of IBD pathogenesis. Further extension of the knowledge of enteric microbiota may lead to insights on the pathogenesis and new therapeutic strategies for IBD.
Bacterial Physiological Phenomena ; Host-Pathogen Interactions ; Humans ; Inflammatory Bowel Diseases/*microbiology/pathology ; Intestinal Mucosa/immunology/microbiology ; Intestines/microbiology/pathology ; T-Lymphocytes/immunology/metabolism

TNF-alpha is a major cytokine involved in inflammatory bowel disease (IBD). In this study, water extract of Grifola frondosa (GFW) was evaluated for its protective effects against colon inflammation through the modulation of TNF-alpha action. In coculture of HT-29 human colon cancer cells with U937 human monocytic cells, TNF-alpha-induced monocyte adhesion to HT-29 cells was significantly suppressed by GFW (10, 50, 100 microg/ml). The reduced adhesion by GFW correlated with the suppressed expression of MCP-1 and IL-8, the major IBD-associated chemokines. In addition, treatment with GFW significantly suppressed TNF-alpha-induced reactive oxygen species production and NF-kappaB transcriptional activity in HT-29 cells. In differentiated U937 monocytic cells, LPS-induced TNF-alpha production, which is known to be mediated through NF-kappaB activation, was significantly suppressed by GFW. In an in vivo rat model of IBD, oral administration of GFW for 5 days (1 g/kg per day) significantly inhibited the trinitrobenzene sulfonic acid (TNBS)-induced weight loss, colon ulceration, myeloperoxidase activity, and TNF-alpha expression in the colon tissue. Moreover, the effect of GFW was similar to that of intra-peritoneal injection of 5-aminosalicylic acid (5-ASA), an active metabolite of sulfasalazine, commonly used drug for the treatment of IBD. The results suggest that GFW ameliorates colon inflammation by suppressing production of TNF-alpha as well as its signaling through NF-kappaB leading to the expression of inflammatory chemokines, MCP-1 and IL-8. Taken together, the results strongly suggest GFW is a valuable medicinal food for IBD treatment, and thus may be used as an alternative medicine for IBD.
Animals ; Cell Adhesion/drug effects/immunology ; Cell Extracts/administration & dosage/*pharmacology ; Chemokine CCL2/biosynthesis/genetics ; Coculture Techniques ; Colon/drug effects/*metabolism/pathology ; Grifola ; HT29 Cells ; Humans ; Inflammatory Bowel Diseases/chemically induced/*drug therapy/pathology/physiopathology ; Interleukin-8/biosynthesis/genetics ; Intestinal Mucosa/*drug effects/metabolism/pathology ; Monocytes/*drug effects/metabolism/pathology ; NF-kappa B/genetics/metabolism ; Peroxidase/metabolism ; Rats ; Rats, Sprague-Dawley ; Reactive Oxygen Species/metabolism ; Stomach Ulcer ; Transcription, Genetic/drug effects ; Trinitrobenzenesulfonic Acid/administration & dosage ; Tumor Necrosis Factor-alpha/*biosynthesis/genetics ; U937 Cells ; Weight Loss

BACKGROUND/AIMS: Nuclear factor-kappa B p65 (NF-kappa B p65), nuclear factor-kappa B1 p50 (NF-kappa B p50) have been shown to play a role in cell proliferation, apoptosis, cytokine production, and oncogenesis. Recently, p38 mitogen-activated protein kinase (MAPK)/ NF-kappa B/ cyclin D1 signaling pathway has been shown to play an important part in the pathogenesis of human cancers. This study was designed to investigate the expression of NF-kappa B p65, NF-kappa B p50, p38 MAPK alpha, and cyclin D1 proteins in premalignant lesions of colon and colorectal adenocarcinoma. METHODS: Paraffin sections of 20 normal mucosa, 20 low-grade tubular adenoma, 20 high-grade tubular adenoma and 64 adenocarcinoma tissues were analysed immunohistochemically for the expression of NF-kappa B p65, NF-kappa B p50, p38 MAPK alpha, and cyclin D1 proteins. RESULTS: The expression of NF-kappa B p65, NF-kappa B p50, and p38 MAPK alpha proteins were significantly higher in adenocarcinoma tissue in comparison with that in normal mucosa, low-grade tubular adenoma, and high-grade tubular adenoma tissues. Expression of NF-kappa B p50 was more frequent in poorly differentiated histologic grade, presence of nodal metastasis, and advanced stage. Expression of p38 MAPK alpha protein was higher in advanced tumor stage, presence of nodal metastasis and advanced stage. Synchronous expression of NF-kappa B p65, NF-kappa B p50, p38 MAPK alpha, and cyclin D1 proteins were significantly higher in adenocarcinoma tissue. CONCULSIONS: With the increased expression of NF-kappa B p65, NF-kappa B p50, and p38 MAPK alpha proteins, p38 MAPK/ NF-kappa B/ cyclin D1 signaling pathway may play a role in the pathogenesis of colorectal carcinoma.
Adenocarcinoma/enzymology/*metabolism/pathology ; Colorectal Neoplasms/enzymology/*metabolism/pathology ; Cyclin D1/immunology/*metabolism ; Data Interpretation, Statistical ; Female ; Humans ; Immunohistochemistry ; Intestinal Mucosa/metabolism ; Male ; Middle Aged ; NF-kappa B/immunology/*metabolism ; NF-kappa B p50 Subunit/immunology/metabolism ; Neoplasm Staging ; Precancerous Conditions/enzymology/*metabolism ; Transcription Factor RelA/immunology/metabolism ; p38 Mitogen-Activated Protein Kinases/*metabolism