Therapeutic Potential of Curcumin in a Rat Model of Dextran Sulfate Sodium-Induced Ulcerative Colitis by Regulating the Balance of Treg/Th17 Cells.

The pathogenesis of ulcerative colitis (UC) remains unclear, and it is believed that an imbalance of regulatory T (Treg) cells and T helper 17 (Th17) cells is related to the occurrence of UC. Curcumin has been confirmed to exert anti-inflammatory effects in bronchial asthma and osteoarthritis by regulating the balance of Treg/Th17 cells. This study aimed to explore the therapeutic potential of curcumin in dextran sulfate sodium (DSS)-induced UC rats by regulating the balance of Treg/Th17 cells. Disease activity index (DAI) scores were calculated. Changes in colon inflammation were observed using hematoxylin and eosin staining. Treg and Th17 cells in the spleen were detected by flow cytometry, and the levels of interleukin (IL)-10 and IL-17A were determined using enzyme-linked immunosorbent assay. In DSS-induced colitis, curcumin significantly ameliorated colitis symptoms by reducing the DAI and increasing colon length. Additionally, curcumin significantly increased the expression of Treg cells and decreased the expression of Th17 cells and the extent of histopathological damage. Furthermore, curcumin increased the expression of IL-10 and decreased the expression of IL-17A. Curcumin attenuates DSS-induced UC injury by regulating Treg/Th17 balance and related cytokine secretion. Thus, curcumin may be a promising therapeutic drug for treating UC.

The JAK2 inhibitor AG490 regulates the Treg/Th17 balance and alleviates DSS-induced intestinal damage in IBD rats.

The pathogenesis of inflammatory bowel disease (IBD) remains unclear, and it is currently believed that an imbalance in regulatory T (Treg) cells/T helper 17 cells (Th17 cells) is related to the occurrence and development of IBD. Recently, the JAK2 inhibitor AG490 has been used in animal models such as rheumatoid arthritis and bronchial asthma models and shown to exert immunoregulatory functions that improve disorder in the Treg/Th17 cell balance. This study aimed to evaluate the effect of AG490 on the intestinal inflammatory process in an IBD rat model. A dextran sulfate sodium (DSS)-induced IBD rat model was established, and disease activity index (DAI) scores were calculated. The histopathological damage score was determined by haematoxylin-eosin (H&E) staining. Treg/Th17 cells in the spleen were detected by flow cytometry. The levels of interleukin (IL)-10, IL-6 and IL-17A were detected by enzyme-linked immunosorbent assay (ELISA). AG490 attenuated DSS-induced IBD injury by regulating the Treg/Th17 balance and related cytokine secretion to reduce the DAI and colonic tissue damage. Thus, AG490 may be a new method for effective treatment of IBD.

Inhibiting microRNA-7 Expression Exhibited a Protective Effect on Intestinal Mucosal Injury in TNBS-Induced Inflammatory Bowel Disease Animal Model.

This study aimed to explore the expression and correlation of microRNA-7 (miR-7) and trefoil factor 3 (TFF3) genes and proteins in inflammatory bowel disease (IBD) mouse models and to elucidate the effect of miR-7 inhibition in the intestinal mucosa in IBD models. A TNBS-induced IBD mouse model was established. Changes in intestinal inflammation were observed by HE staining, and the expression levels of miR-7 and TFF3 were detected by RT-PCR. After miRNA-antagomir injection, the degree of colonic tissue damage and the expression levels of miR-7 and TFF3 in intestinal tissues were compared. TNBS-induced IBD mice showed significant weight loss, significantly decreased disease activity index (DAI), and a significantly increased pathological damage score. miR-7 was highly expressed in the colon tissue of IBD mice, and TFF3 was downregulated. Inhibition of the expression of miR-7 improved the stool characteristics and fecal occult blood (OB) of IBD mice, significantly increased the expression of TFF3 protein, and decreased the pathological damage scores. In the IBD mouse model, miR-7 posttranscriptionally regulates TFF3. The inhibition of miR-7 expression improves some clinical manifestations of IBD mice, reduces the pathological damage of the intestinal mucosa, and shows a protective effect in IBD.

[Efficacy of infliximab in the treatment of Crohn's disease in children].

OBJECTIVE: To evaluate the efficacy and safety of infliximab in the treatment of Crohn's disease in children. METHODS: Thirteen children who were diagnosed with Crohn's disease and received routine comprehensive treatment and infliximab (5 mg/kg) between January 2011 and December 2014 were enrolled. The changes in their clinical manifestations, laboratory indices, and Pediatric Crohn's Disease Activity Index (PCDAI) after the 30-week treatment were analyzed retrospectively. Meanwhile, endoscopy was performed to evaluate therapeutic effects. RESULTS: The symptoms such as abdominal pain, diarrhea, and bloody stool were relieved soon after infliximab treatment, with no recurrence observed; after the 30-week treatment, the white blood cell count, erythrocyte sedimentation rate, C-reactive protein, and the PCDAI decreased, while the hemoglobin increased significantly compared with those before treatment (P<0.05). After infliximab treatment, two children underwent endoscopy. The endoscopy showed that one child was cured, and the other child failed to respond to the treatment. No adverse drug reactions were seen in all patients. CONCLUSIONS: Infliximab treatment has significant clinical effects in children with Crohn's disease, with no obvious adverse reactions, and therefore, it can be applied as one of the preferred alternatives for treatment of Crohn's disease in children.

The protective effect of trefoil factor 3 on the intestinal tight junction barrier is mediated by toll-like receptor 2 via a PI3K/Akt dependent mechanism.

Trefoil factor peptides are highly conserved secreted molecules characterized by heat and enzymatic digestion resistance. Intestinal trefoil factor 3 (TFF3) protects and repairs the gastrointestinal mucosa and restores normal intestinal permeability, which is dependent on the integrity of the tight junction (TJ) barrier and the TJ associated proteins claudin-1, zona occludens-1 (ZO-1) and occludin. Despite the important role of intestinal barrier dysfunction in the pathogenesis of inflammatory bowel diseases, the underlying mechanisms and associated molecules remain unclear. In the present study, we show that TFF3 and toll-like receptor 2 (TLR2) are functionally linked and modulate intestinal epithelial permeability via a mechanism that involves the PI3K/Akt pathway. We used the Caco-2 cell model to show that TLR2 and TFF3 inhibit the IL-1ß induced increase in permeability and release of proinflammatory cytokines, and that this effect is mediated by activation of PI3K/Akt signaling. TLR2 silencing downregulated the expression of TFF3 and overexpression of TLR2 and TFF3 increased the levels of phospho-Akt. TFF3 overexpression significantly upregulated the expression of ZO-1, occludin and claudin-1 and this effect was abrogated by inhibition of the PI3K/Akt pathway. Taken together, our results indicate that TLR2 signaling selectively enhances intestinal TJ barrier integrity through a mechanism involving TFF3 and the activation of the PI3K/Akt pathway.

[Screening and identification of high-yield poly(ß-malic acid) bacterial strain].

OBJECTIVE: To isolate and identify the high-yield poly-malic acid (PMLA) bacterial strains from the nature. METHODS: Samples were collected and cultured. The high-yield PMLA bacterial strains were screened through morphological observation, qualitative PMLA tests by HPLC and ITS sequence analysis on the isolated bacterial strains. RESULTS: A high-yield PMLA strain II 04 was isolated, the yield of PMLA of the strain reached to 26.23g/L in the rotary shaker at 25 degree for 7d. From morphological observation and ITS sequences analysis, the strain belonged to Aureobasidium pullulans, and named as Aureobasidium pullulans ZUCC-41. CONCLUSION: A high-yield bacterial strain has been isolated from the nature and identified to be Aureobasidium pullulans.

Protective effect of intestinal trefoil factor on injury of intestinal epithelial tight junction induced by platelet activating factor.

Intestinal barrier dysfunction plays an important role in the pathogenesis of inflammatory bowel disease (IBD). To evaluate the effect of intestinal trefoil factor (ITF) on increased intestinal permeability and its association with tight junction proteins, an in vitro intestinal epithelia barrier model was established with Caco-2 cells and treated with platelet-activating factor (PAF). We found that exposing cells to 0.3 M ITF (30 min before or 30 min after PAF treatment) attenuated the PAF-induced changes in transepithelial electrical resistance and Lucifer yellow flux. A quantitative RT-PCR and western blot analysis revealed that ITF suppressed PAF-induced downregulation of tight junction proteins claudin-1 and ZO-1 expression; furthermore, an abnormal localization and distribution of these proteins was inhibited, as assessed by immunofluorescence staining. These results suggest that ITF decreases mucosal permeability and shows potential as a therapy for treating IBD.

Disruption of the F-actin cytoskeleton and monolayer barrier integrity induced by PAF and the protective effect of ITF on intestinal epithelium.

To explore whether platelet-activating factor (PAF) can disrupt the intestinal epithelial barrier directly and is associated with structural alterations of the F-actin-based cytoskeleton, and to observe the protective effect of intestinal trefoil factor (ITF), we establish an intestinal epithelia barrier model using Caco-2 cells in vitro. Transepithelial electrical resistance and unidirectional flux of lucifer yellow were measured to evaluate barrier permeability; immunofluorescent staining and flow cytometry were applied to observe morphological alterations and to quantify proteins of the F-actin cytoskeleton: the tight junction marker ZO-1 and Claudin-1 were observed using immunofluorescent staining. PAF significantly increased paracellular permeability, at the same time, F-actin and tight junction proteins were disrupted. It was thought that ITF could reverse the high permeability by restoring normal F-actin, ZO-1 and Claudin-1 structures. These results collectively demonstrated that PAF plays an important role in the regulation of mucosal permeability and the effects of PAF are correlated with structural alterations of the F-actin-based cytoskeleton and of tight junctions. ITF can protect intestinal epithelium against PAF-induced disruption by restricting the rearrangement of the F-actin cytoskeleton and of tight junctions.

Effects of trefoil peptide 3 on expression of TNF-alpha, TLR4, and NF-kappaB in trinitrobenzene sulphonic acid induced colitis mice.

The trefoil factor (TFF) peptides are major secretory products of mucus cells of the gastrointestinal tract. There were evidences that administration of recombinant human TFF3 is effective in treatment of models of colitis, but the mechanism of the effects of rTFF3 is not fully understood. The main aims of this study is to evaluate effects of intraperitoneal injection recombinant human TFF3 on the expression of tumour necrosis factor alpha (TNF-alpha), toll-like receptor 4(TLR4), and nuclear factor kappaB (NF-kappaB) in trinitrobenzene sulphonic acid (TNBS) induced colitis mice. Distal colitis was induced in BALB/C mice by intracolonic administration of TNBS in ethanol. Treated with administration rhTFF3 for treatment group(5 mg/ml; approximately 0.5 mg/mouse), and normal saline for control for 5 consecutive days. Colonic damage score, tissue myeloperoxidase (MPO) activity, TLR4, NF-kappaB mRNA expression, and tissue TNF-alpha, TLR4, NF-kappaB production were determined, respectively. Once daily application of hTFF3 for 5 days after TNBS/ethanol had been injected, both microscopic and macroscopic injury and inflammatory index had been reduced compared with controls. In addition, decreased tissue TNF-alpha, TLR4, NF-kappaB production, and TLR4, NF-kappaB mRNA expression had been found. This study has shown that hTFF3 may have therapeutic potential in the treatment of inflammatory bowel disease, and one of the mechanisms may related to inhibit the TLR4/NF-kappaB signaling pathways.

[Protective effects of recombinant intestinal trefoil factor against intestinal injuries induced by endotoxin in young rats].

OBJECTIVE: This study aimed to investigate the protective effects of recombinant intestinal trefoil factor (rITF) against intestinal injuries and the possible mechanism by examining the changes of diamine oxidase (DAO) and TNF-alpha and the intestinal ultrastructural changes in lipopolysaccharide (LPS) induced intestinal injuries. METHODS: Ninety-six ten-day-old Wistar rats were randomly injected with either normal saline (1 mL/kg, Control group), LPS (1 mL/kg) or LPS (1 mL/kg) + rITF (0.1 mL) intraperioneally. At 2, 6, 24 and 72 hrs after administration plasma DAO activity was determined using absorption spectrometry; and the intestinal protein and mRNA expression of TNF-alpha were measured using immunohistochemistry and RT-PCR methods. The intestinal ultrastructural changes were observed by electron microscopy. RESULTS: The plasma DAO activity in the LPS group began to increase at 2 hrs, peaked at 6 hrs and remained at significantly higher levels until 72 hrs after administration compared with the Control group (P < 0.01). The plasma DAO activity in the LPS + rITF group decreased noticeably compared with the LPS group at all time points (P < 0.01 or 0.05). A significant difference in the plasma DAO activity was only observed at 6 hrs after administration between the LPS + rITF and the Control group. The expression of TNF-alpha protein in the LPS group significantly increased at each time point, peaking at 6 hrs after LPS administration, with the IODT of TNF-alpha of 37,247.64 +/- 3,387.59 vs 6,191.02 +/- 482.32 (P < 0.01) compared with the Control group. rITF treatment decreased the expression of TNF-alpha protein although it remained significantly higher than in the Control group (P < 0.01). The TNF-alpha mRNA was weakly expressed in the Control group but strikingly increased after LPS injection (P < 0.01). Compared with the LPS group, the TNF-alpha mRNA expression in the LPS + rITF group decreased at all time points (P < 0.01 or 0.05). Vacuole changes of mitochodrium, cell nucleus condense, break and depletion of part of microvilli, and widen and disrupted tight junction were observed in the LPS group. The ultrastructural changes of intestinal tissues were improved in the LPS + rITF group. CONCLUSIONS: rITF can decrease the plasma DAO activity and inhibit the expression of TNF-alpha, resulting in a protective effect against intestinal injuries induced by LPS in young rats.

Expression of intestinal trefoil factor, proliferating cell nuclear antigen and histological changes in intestine of rats after intrauterine asphyxia.

AIM: To study the expressions of intestinal trefoil factor (ITF) and proliferating cell nuclear antigen (PCNA) and histologic changes in intestine, to investigate the relationship between ITF and intestinal damage and repair after intrauterine hypoxia so as to understand the mechanism of intestinal injury and to find a new way to prevent and treat gastrointestinal diseases. METHODS: Wistar rats, pregnant for 21 d, were used to establish animal models of intrauterine asphyxia by clamping one side of vessels supplying blood to uterus for 20 min, another side was regarded as sham operation group. Intestinal tissues were taken away at 0, 24, 48 and 72 h after birth and stored in different styles. ITF mRNA was detected by RT-PCR. PCNA expression was measured by immunohistochemistry. Intestinal tissues were studied histologically by HE staining in order to observe the areas and degree of injury and to value the intestinal mucosa injury index (IMDI). RESULTS: ITF mRNA appeared in full-term rats and increased with age. After ischemia, ITF mRNA was decreased to the minimum (0.59+/-0.032) 24 h after birth, then began to increase higher after 72 h than it was in the control group (P<0.01). PCNA positive staining located in goblet cell nuclei. The PCNA level had a remarkable decline (53.29+/-1.97) 48 h after ischemia. Structure changes were obvious in 48-h group, IMDI (3.40+/-0.16) was significantly increased. Correlation analyses showed that IMDI had a negative correlation with ITF mRNA and PCNA (r = -0.543, P<0.05; r = -0.794, P<0.01, respectively). CONCLUSION: Intrauterine ischemia can result in an early decrease of ITF mRNA expression. ITF and PCNA may play an important role in the damage and repair of intestinal mucosa.