Small Intestinal Injury In Mice Research Articles

Staphylococcal Enterotoxin A Induces Intestinal Barrier Dysfunction and Activates NLRP3 Inflammasome via NF-κB/MAPK Signaling Pathways in Mice.

Staphylococcal enterotoxin A (SEA), the toxin protein secreted by Staphylococcus aureus, can cause staphylococcal food poisoning outbreaks and seriously threaten global public health. However, little is known about the pathogenesis of SEA in staphylococcal foodborne diseases. In this study, the effect of SEA on intestinal barrier injury and NLRP3 inflammasome activation was investigated by exposing BALB/c mice to SEA with increasing doses and a potential toxic mechanism was elucidated. Our findings suggested that SEA exposure provoked villi injury and suppressed the expression of ZO-1 and occludin proteins, thereby inducing intestinal barrier dysfunction and small intestinal injury in mice. Concurrently, SEA significantly up-regulated the expression of NLRP3 inflammasome-associated proteins and triggered the mitogen-activated protein kinase (MAPK) and nuclear factor kappa-B (NF-κB) signaling pathways in jejunum tissues. Notably, selective inhibitors of MAPKs and NF-κB p65 ameliorated the activation of NLRP3 inflammasome stimulated by SEA, which further indicated that SEA could activate NLRP3 inflammasome through NF-κB/MAPK pathways. In summary, SEA was first confirmed to induce intestinal barrier dysfunction and activate NLRP3 inflammasome via NF-κB/MAPK signaling pathways. These findings will contribute to a more comprehensive understanding of the pathogenesis of SEA and related drug-screening for the treatment and prevention of bacteriotoxin-caused foodborne diseases via targeting specific pathways.

Role of Sulforaphane in Protection of Gastrointestinal Tract Against H. pylori and NSAID-Induced Oxidative Stress.

Background: Sulforaphane (SFN), a phytochemical found in abundance in broccoli sprouts, potently induces a variety of antioxidant enzymes, and thereby protects cells from injury induced by various kinds of oxidative stresses. It has been suggested that both H. pylori infection and intake of non-steroidal anti-inflammatory drugs (NSAIDs) induce chronic oxidative stress in gastrointestinal (GI) mucosa, thereby causing mucosal injury in the GI tract. Therefore, it would be a reasonable assumption that SFN protects GI mucosa against oxidative injury induced by H. pylori or NSAIDs.Methods: We examined the effects of SFN on H. pylori viability in vitro, levels of gastritis in H.pylori-infected mice in vivo, and in H.pylori-infected human subjects. We also examined the effects of SFN on NSAID-induced small intestinal injury in mice.Results: Our data from the H. pylori infection study clearly demonstrated that SFN inhibited H. pylori viability both in vitro and in vivo, and mitigated H. pylori-induced gastritis in mice and humans. Similar-ly, our study on NSAID-induced small intestinal injury showed that SFN not only mitigated aspirin-induced injury of small intestinal epithelial cells in vitro, but also ameliorated indomethacin-induced small intestinal injury in mice in vivo.Conclusions: These data strongly suggest that SFN contributes to the protection of GI mucosa against oxidative injury induced by H. pylori or NSAIDs.

Preventative Effects of Sodium Alginate on Indomethacin-induced Small-intestinal Injury in Mice.

Recent advances in diagnostic technologies have revealed that nonsteroidal anti-inflammatory drugs (NSAIDs) can cause serious mucosal injury in the upper and lower gastrointestinal tract (including the small intestine). A drug to treat NSAID-induced small-intestinal injury (SII) is lacking. Sodium alginate is a soluble dietary fiber extracted from brown seaweed and its solution has been used as a hemostatic agent to treat gastrointestinal bleeding due to gastric ulcers. Whether sodium alginate has therapeutic effects on NSAID-induced SII and its mechanism of action are not known. Here, we investigated if administration of two forms (high-molecular-weight (HMW) and low-molecular-weight (LMW)) of sodium alginate could ameliorate indomethacin-induced SII. Pretreatment with HMW sodium alginate or LMW sodium alginate before indomethacin administration improved ulceration and the resultant intestinal shortening was associated with reduced histological severity of mucosal injury and ameliorated mRNA expression of inflammation-related molecules in the small intestine. We found that mRNAs of secretory Muc2 and membrane-associated Muc1, Muc3 and Muc4 were expressed in the small intestine. mRNA expression of Muc1-4 was increased in indomethacin-induced SII, and these increases were prevented by sodium alginate. Thus, administration of sodium alginate could be a therapeutic approach to prevent indomethacin-induced SII.

Small intestinal injury in mice infected with respiratory influenza A virus: evidence for virus induced gastroenteritis.

Influenza in humans is often accompanied by gastroenteritis-like symptoms such as diarrhea and abdominal pain nausea, but the underlying mechanism remains unclear. Mice infected with three subtypes of respiratory influenza A virus (IAV), particularly H5N1 and H7N2, developed intestinal injury. The avian H5N1 and H7N2 IAV were detected in the small intestine, whereas the human H1N1 was not detected. Section staining with the sialic acid (SA) receptor demonstrated that the small intestine mainly expressed SA α2, 3 Gal instead of SA α2, 6 Gal which preferentially binds to avian IAV. The number of goblet and sIgA cells in the small intestine increased, whereas CD4(+) and CD8(+) T cells decreased in all infected mice except for CD8(+) T cells increased in H7N2 infected mice. Respiratory IAV infection, particularly infected by avian IAV, can cause small intestine structural damage and modify the local immune response, thereby resulting in gastroenteritis-like symptoms.

Impaired skin barrier function in mice with colon carcinoma induced by azoxymethane and dextran sodium sulfate.

We have previously reported that impaired skin barrier function was induced by small intestinal injury in mice. Therefore, we postulated that other intestinal diseases might also influence skin barrier function. In this study, we evaluated the skin barrier function of hairless mice with colon carcinoma that was induced by azoxymethane (AOM) and dextran sodium sulfate (DSS). In mice treated with these drugs, we observed elevated transepidermal water loss and reduced skin hydration levels, compared to those in the control mice. In addition, plasma nitrogen di/trioxide (NO2(-)/NO3(-)) levels were significantly elevated, and expression of type I collagen was significantly reduced in the treated mice, compared to those in control. These results suggest that impaired skin barrier function occurs in mice when colon carcinoma is present.

Preventive effect of agaro-oligosaccharides on non-steroidal anti-inflammatory drug-induced small intestinal injury in mice

Preventive effect of agaro-oligosaccharides on non-steroidal anti-inflammatory drug-induced small intestinal injury in mice

Skin disruption is associated with indomethacin-induced small intestinal injury in mice.

One mechanism by which non-steroidal anti-inflammatory drugs (NSAIDs) cause intestinal injury is by inducing matrix metalloproteinases (MMPs) that degrade and remodel the extracellular matrix. In addition to the intestinal mucosa, MMPs are expressed in the skin and can be activated by mast cell-secreted tryptase. We therefore investigated whether intestinal injury resulting from treatment with the NSAID indomethacin induced MMPs in the skin of mice and caused an associated disruption of skin function. Hairless mice and mast cell-deficient mice were administered indomethacin, after which damage to the jejuna and skin was assessed with immunohistochemistry and Western blotting. The plasma concentration of inflammatory mediators was assessed to evaluate potential pathways for signalling skin disruption in response to intestinal injury. In hairless mice with intestinal injury, transepidermal water loss (TEWL) was higher and skin hydration was lower than in control mice. The expression levels of mast cells, tryptase, MMP-1 and MMP-9 were also increased, with concurrent degradation of types I and IV collagen. In contrast, no changes in skin TEWL or skin hydration were observed in mast cell-deficient mice with indomethacin-induced intestinal injury. In all mice evaluated, the plasma concentrations of IgE, IgA, histamine and TNF-α were increased in response to indomethacin treatment. Skin disruption was strongly associated with indomethacin-induced small intestinal injury, and the activation of mast cells and induction of tryptase, MMP-1 and MMP-9 are critical to this association.

Preventive effect of agaro‐oligosaccharides on non‐steroidal anti‐inflammatory drug‐induced small intestinal injury in mice

Non-steroidal anti-inflammatory drugs (NSAIDs), which are commonly used in clinical medicine, cause erosion, ulcers, and bleeding in the gastrointestinal tract. No effective agent for the prevention and treatment of small intestinal injury by NSAIDs has been established. This study investigates the effects of agaro-oligosaccharides (AGOs) on NSAID-induced small intestinal injury in mice. Mice were treated with indomethacin, an NSAID, to induce intestinal injury. The respective degrees of mucosal injury of mice that received AGO and control mice were compared. Heme oxygenase-1 (HO-1) expression using quantitative real-time polymerase chain reaction (qRT-PCR), Western blotting, and immunohistochemistry were measured. The expression of keratinocyte chemoattractant (KC) was measured using qRT-PCR and enzyme-linked immunosorbent assay. AGO administration induced HO-1 expression in mouse small intestinal mucosa. Induction was observed mainly in F4/80 positive macrophages. The increased ulcers score, myeloperoxidase activity, and KC expression by indomethacin were inhibited by AGO administration. Conversely, HO inhibitor cancelled AGO-mediated prevention of intestinal injury. In mouse peritoneal macrophages, AGOs enhanced HO-1 expression and suppressed lipopolysaccharide-induced KC expression. Furthermore, AGOs enhanced the expressions of alternatively activated macrophage markers arginase-1, mannose receptor-1, and chitinase 3-like 3. Results suggest that oral administration of AGOs prevents NSAID-induced intestinal injury.

Effect of 18β-glycyrrhetinic acid and hydroxypropyl γcyclodextrin complex on indomethacin-induced small intestinal injury in mice

Non-steroidal anti-inflammatory drugs (NSAIDs)-induced small intestinal injury is a serious clinical event with recent advances of diagnostic technologies, but a successful therapeutic method to treat such injuries is still lacking. Licorice, a traditional herbal medicine, and its derivatives have been widely used for the treatment of a variety of diseases due to their extensive biological actions. However, it is unknown whether these derivatives have an effect on NSAIDs-induced small intestinal damage. Previously, the anti-inflammatory effects of three compounds extracted from the licorice root, glycyrrhizin, 18β-glycyrrhetinic acid, and dipotassium glycyrrhizinate, were compared in vitro cell culture. The most prominent inhibitory effect on the tumor necrosis factor-α (TNF-α) production was observed with the administration of 18β-glycyrrhetinic acid as an active metabolite of glycyrrhizin. In this study, a complex compound of 18β-glycyrrhetinic acid and hydroxypropyl γcyclodextrin was examined to improve the oral bioavailability. After administration of this complex to indomethacin treated mice, a significantly high plasma concentration of 18β-glycyrrhetinic acid was detected using the tandem mass spectrometry coupled with the HPLC. Furthermore, the complex form of 18β-glycyrrhetinic acid and hydroxypropyl γcyclodextrin reduced mRNA expressions of TNF-α, interleukin (IL)-1β, and IL-6, which was histologically confirmed in the improvement of indomethacin-induced small intestinal damage. These results suggest that the complex of 18β-glycyrrhetinic acid and hydroxypropyl γcyclodextrin has the potential therapeutic value for preventing the adverse effects of indomethacin-induced small intestinal injury.

Mo2016 Effect of Ghrelin on Indomethacin-Induced Small Intestinal Injury in Mice

Mo2016 Effect of Ghrelin on Indomethacin-Induced Small Intestinal Injury in Mice

Hemin ameliorates indomethacin‐induced small intestinal injury in mice through the induction of heme oxygenase‐1

Although non-steroidal anti-inflammatory drugs can induce intestinal injury, the mechanisms are not fully understood, and treatment has yet to be established. Heme oxygenase-1 (HO-1) has recently gained attention for anti-inflammatory and cytoprotective effects. This study aimed to investigate the effects of hemin, an HO-1 inducer, on indomethacin-induced enteritis in mice. Enteritis was induced by single subcutaneous administration of indomethacin (10 mg/kg) in male C57BL/6 mice. Hemin (30 mg/kg) was administered by intraperitoneal administration 6 h before indomethacin administration. Mice were randomly divided into four groups: (i) sham + vehicle; (ii) sham + hemin; (iii) indomethacin + vehicle; or (iv) indomethacin + hemin. Enteritis was evaluated by measuring ulcerative lesions. Myeloperoxidase activity was measured as an index of neutrophil accumulation. The mRNA expression of inflammatory cytokines and chemokines, such as tumor necrosis factor-α, monocyte chemoattractant protein-1, macrophage inflammatory protein-1α, and keratinocyte chemoattractant, were analyzed by real-time polymerase chain reaction. The area of ulcerative lesions, myeloperoxidase activity, and mRNA expression of inflammatory cytokines and chemokines were significantly increased in mice administrated with indomethacin compared with vehicle-treated sham mice. Development of intestinal lesions, increased levels of myeloperoxidase activities, and mRNA expressions of inflammatory cytokines and chemokines were significantly suppressed in mice treated with hemin compared with vehicle-treated mice. Protective effects of hemin were reversed by co-administration of tin protoporphyrin, an HO-1 inhibitor. Induction of HO-1 by hemin inhibits indomethacin-induced intestinal injury through upregulation of HO-1. Pharmacological induction of HO-1 may offer a novel therapeutic strategy to prevent indomethacin-induced small intestinal injury.

Role of tumor necrosis factor-α in the pathogenesis of indomethacin-induced small intestinal injury in mice

The pathogenesis of small intestinal damage caused by non-steroidal anti-inflammatory drugs (NSAIDs) such as indomethacin is still unclear. For this reason, there is currently no therapeutic strategy for ameliorating such damage. On the other hand, molecular treatment strategies targeting tumor necrosis factor (TNF)-α exert beneficial effects on intestinal lesions in patients with inflammatory bowel disease (IBD). To clarify the participation of TNF-α in NSAID-induced small intestinal damage, we investigated the effects of indomethacin administration in mice with targeted deletion of the TNF-α gene. Indomethacin (10mg/kg) was administered subcutaneously to male C57BL/6 (wild-type: WT) mice and TNF-α-deficient (TNF-α-/-) mice to induce small intestinal damage. The ulcer score, the tissue-associated myeloperoxidase (MPO) activity as an index of neutrophil infiltration, and the expression of keratinocyte chemoattractant (KC) mRNA in the small intestinal mucosa were measured. In addition, we performed a TUNEL assay to evaluate indomethacin-induced apoptosis of intestinal epithelial cells and measured the expression of caspase-3 protein and Bcl-2 mRNA. The ulcer score, MPO activity, and expression of KC mRNA were significantly increased after indomethacin administration. These increases were significantly inhibited in TNF-α-/- mice compared with WT mice. Apoptotic cells were observed by the TUNEL assay in the area of the ulcerative lesion, and they were significantly fewer in TNF-α-/- mice compared with WT mice. The expression of cleaved caspase-3 protein was induced by indomethacin administration, and significantly inhibited in TNF-α-/- mice compared with that of WT mice. The expression level of Bcl-2 mRNA in indomethacin-treated TNF-α-/- mice was significantly higher than that in WT mice. TNF-α plays an important role in the pathogenesis of indomethacin-induced small intestinal damage. These results suggest that TNF-α could become a new therapeutic target for NSAID-induced small intestinal damage.

Cattle Bile Aggravates Diclofenac Sodium‐Induced Small Intestinal Injury in Mice

Cattle bile (CB) has long been used in Japan as an ingredient of digestive medicines. Bile acids are major chemical constituents of CB, and CB ingestion is assumed to affect small intestinal injury induced by nonsteroidal anti-inflammatory drugs (NSAIDs). Mice were fed a diet supplemented with or without CB for 7 days and treated with diclofenac sodium (DIF) to induce small intestinal injury. Lesion formation was enhanced, and PGE2 content and COX expression levels were elevated in the small intestine of DIF-treated mice fed the CB diet compared with those fed the control diet. The administration of a reconstituted mixture of bile acids found in CB enhanced lesion formation in DIF-treated mice. CB administration elevated the contents of CB-derived bile acids in the small intestine, some of which exhibited a high cytotoxicity to cultured intestinal epithelial cells. These results suggest that the elevated levels of CB-derived cytotoxic bile acids in the small intestine contribute to the aggravation of DIF-induced small intestinal injury. The use of CB may be limited during the therapy of inflammatory diseases with NSAIDs.

M1845 Role of TNF-α in the Pathogenesis of Indomethacin-Induced Small Intestinal Injury in Mice

Role of TNF-α in the Pathogenesis of Indomethacin-Induced Small Intestinal Injury in Mice Kohei Fukumoto, Yuji Naito, Tomohisa Takagi, Shinya Yamada, Ryusuke Horie, Ken Inoue, Akihito Harusato, Ikuhiro Hirata, Tatsushi Omatsu, Etsuko Kishimoto, Katsura Mizushima, Yasuko Hirai, Kazuhiko Uchiyama, Takeshi Ishikawa, Osamu Handa, Hideyuki Konishi, Naoki Wakabayashi, Nobuaki Yagi, Satoshi Kokura, Hiroshi Ichikawa, Masakazu Kita, Toshikazu Yoshikawa

W1580: Geranylgeranylacetone Protects Against NSAIDs-Induced Gastric and Small Intestinal Mucosal Injuries in Healthy Subjects: A Prospective Randomised Study Compared With Famotidine

A variety of factors are involved in the formation of lesions induced by nonsteroidal anti-inflammatory drugs(NSAIDs) in the small intestine, considered unaffected by acid, including intestinal flora, bile, and mucous, and as yet there are no established preventive or therapeutic measures.Geranylgeranylacetone(GGA), a gastric mucosal protective agent, is used in the treatment of gastritis and gastric ulcers. It also induces heat shock proteins, and has been shown to inhibit NSAID-induced gastric mucosal injury in humans and small intestinal injury in mice.

Recognition of Double-Stranded RNA by TLR3 Induces Severe Small Intestinal Injury in Mice

The role of TLRs on intestinal epithelial cells (IECs) is controversial, and the mechanisms by which TLRs influence mucosal homeostasis are obscure. In this study, we report that genomic dsRNA from rotavirus, and its synthetic analog polyinosinic-polycytidylic acid (poly(I:C)), induce severe mucosal injury in the small intestine. Upon engaging TLR3 on IECs, dsRNA triggers IECs to secrete IL-15, which functions to increase the percentage of CD3+NK1.1+ intestinal intraepithelial lymphocytes (IELs) and enhances the cytotoxicity of IELs. Moreover, The CD3+NK1.1+ IELs are proved as CD8alphaalpha+ IELs. These results provide direct evidence that abnormal TLR3 signaling contributes to breaking down mucosal homeostasis and the first evidence of pathogenic effects mediated by CD8alphaalpha+ IELs. The data also suggest that genomic dsRNA may be involved in the pathogenesis of acute rotavirus gastroenteritis.

Mechanisms of Intestinal Epithelial Cell Regeneration from Radiation-Induced Small Intestinal Injury in Mice

Background: Signaling by IL-4 and IL-13 is transduced via a receptor complex of IL-13Rα1 and IL-4Rα chains. However, contribution of a putative decoy receptor of IL-13, IL-13Rα2, is not clear. The aim of this study was to determine the significance of Th2-type cytokines in the gastrointestinal (GI) epithelial cell repair system. Methods: We compared the tissue recovery in wild type (WT) and IL-4 receptor α deficient (IL-4R KO) mice following mucosal damage induced by 3 Gy-whole body γ-irradiation. The expression of IL-4, IL-13 and related molecules in the regenerative process were assessed. Results: Expression of IL-13Rα2 dramatically increased in myofibroblasts and fibroblasts on day 3. In contrast, in IL-4R KO mice, intestinal tissue repair after irradiation was delayed, and the transient upregulation of IL-13Rα2 was not seen. Injection of a soluble IL-13Rα2-immunoglobulin chimeric protein to both of WT and IL-4R KO mice resulted in the improvement of tissue recovery. Addition of IL-13 into primary tissue culture of the jejunum induced epithelial cell damage with decreased expression of membrane bound β-catenin. Conclusions: Our study demonstrated that IL-13 has a potential to induce epithelial cell damage, and IL-13Rα2 functions as a regulatory factor in the regeneration of intestinal epithelial cells.

IL-13 Receptor α2 Promotes Epithelial Cell Regeneration From Radiation–Induced Small Intestinal Injury in Mice

The cytokines interleukin (IL)-4 and IL-13 have pleiotropic effects on a variety of cell types and impact both pathologic changes and tissue remodeling. The aim of this study was to clarify the roles of IL-13 receptor alpha2 (IL-13Ralpha2), which is the high-affinity decoy receptor for IL-13, in gastrointestinal tract epithelial cell turnover and repair. We have compared the regenerative process following mucosal damage induced by whole-body 3-Gy X-ray irradiation of wild-type (WT) and IL-4 receptor alpha gene-deficient (IL-4R(-/-)) mice. Then we treated mice with IL-13Ralpha2 human immunoglobulin (Ig) chimeric protein. Up-regulation of mRNA levels for IL-13 in NK cells in the lamina propria was seen after irradiation of WT mice. Concomitant with vigorous epithelial cell division in the jejunum following irradiation, expression of the IL-13Ralpha2 dramatically increased in myofibroblasts and fibroblasts. In contrast, epithelial cell repair was delayed in IL-4R(-/-) mice, which did not show transient up-regulation of IL-13Ralpha2, although up-regulation of IL-13 was seen. Addition of IL-13 but not IL-4 to primary cultures of small intestine from both WT and IL-4R(-/-) mice induced epithelial cell damage. Treatment of IL-4R(-/-) mice with IL-13Ralpha2-Ig resulted in increased numbers of dividing epithelial cells and improved tissue repair after irradiation. Further, treatment with IL-13Ralpha2-Ig increased numbers of microcolonies of regenerating epithelial cells in the intestine of WT mice after severe damage induced by 12-Gy irradiation. The IL-13Ralpha2 is a major regulatory factor involved in the regeneration of epithelial cells in the gastrointestinal tract.