NF-kappaB p65 antisense oligonucleotides may serve as a novel molecular approach for the treatment of patients with ulcerative colitis

Role of moxibustion in inflammatory responses during treatment of rat ulcerative colitis

AIM: To investigate the efficacy of moxibustion in ulcerative colitis (UC) rats from morphological, immunological and molecular biological perspectives.

METHODS: Thirty-two Sprague-Dawley rats were randomly assigned to a blank control group (normal rats, n = 6) and a model replication (MR) group (UC rats, n = 26). A UC model was established by 2,4,6-trinitrobenzenesulfonic acid/dextran sulfate sodium enema. Rats in the MR group were further randomly assigned to a 9-min moxibustion (9M) group (9 moxa-cone, n = 6), 6-min moxibustion (6M) group (6 moxa-cone, n = 6), 3-min moxibustion (3M) group (3 moxa-cone, n = 6), and a waiting list control (WLC) group (no moxibustion treatment, n = 6). Rats in the moxibustion treatment group were treated in 14 sessions over 28 d. Disease activity, local tissue morphology, serum level of interleukin (IL)-8 and IL-10, and expression of Toll-like receptor (TLR)9 as well as nuclear factor (NF)-κB p65 in colonic tissue were determined by disease activity index (DAI), hematoxylin and eosin staining, electron microscopy, enzyme-linked immunosorbent assay and Western blotting, respectively.

RESULTS: DAI was lowest in the 9M group and highest in the WLC group. The differences in DAI between the moxibustion treatment (3M, 6M, 9M) and no treatment groups were significant for all one-to-one comparisons (0.60 ± 0.54 vs 1.20 ± 0.44, 0.60 ± 0.54 vs 1.80 ± 0.45, 0.60 ± 0.54 vs 3.0 ± 0.45, respectively, P < 0.05). Light and electron microscopy showed that the neatness of the glandular arrangement in colonic mucosal epithelia gradually increased in the WLC, 3M, 6M to 9M groups. IL-8 level successively decreased while IL-10 level increased from the WLC to 3M, 6M and 9M groups. The differences among these groups were significant for all comparisons (105.46 ± 8.75 vs 76.61 ± 3.58, 105.46 ± 8.75 vs 69.78 ± 1.87, 105.46 ± 8.75 vs 67.41 ± 1.84, respectively, P < 0.01 for IL-8; and 30.83 ± 1.29 vs 75.64 ± 1.90, 30.83 ± 1.29 vs 80.90 ± 3.16, 30.83 ± 1.29 vs 83.46 ± 2.37, respectively, P < 0.01 for IL-10), except comparison of 6M vs 9M. Expression of TLR9 and NF-κB p65 decreased in order: highest in the WLC group and lowest in the 9M group. In addition, the differences among the WLC, 3M, 6M and 9M groups were significant for all comparisons (0.492 ± 0.026 vs 0.380 ± 0.022, 0.492 ± 0.026 vs 0.355 ± 0.005, 0.492 ± 0.026 vs 0.327 ± 0.015, respectively, P < 0.05 for TLR9; and 0.436 ± 0.041 vs 0.326 ± 0.022, 0.436 ± 0.041 vs 0.293 ± 0.006, 0.436 ± 0.041 vs 0.265 ± 0.017, respectively, P < 0.05 for NF-κB p65).

CONCLUSION: Moxibustion repairs damaged colonic mucosa, suppresses serum IL-8, activates serum IL-10 level, and decreases expression of TLR-9 and NF-κB p65 in UC rats.

Current overview of extrinsic and intrinsic factors in etiology and progression of inflammatory bowel diseases

Inflammatory bowel diseases (IBD) are chronic, relapsing disorders affecting gastrointestinal (GI) tract and associated with intestinal mucosa damage and inflammation. The principal therapeutic goals in IBD include control of the intestinal inflammation and treatment of the major symptoms, mainly abdominal pain and diarrhea. Current therapeutic strategies for IBD rely on the use of non-specific anti-inflammatory agents and immunosuppressive drugs (e.g. aminosalicylates, monoclonal antibodies, and antibiotics), which cause severe side effects, and - in a significant number of patients - do not induce long-term benefits. In this review, we summarize the epidemiology and the most important risk factors of IBD, including genetic, immunological and environmental. Our main focus is to discuss pharmacological targets for current and future treatments of IBD.

Activation of adenosine A3 receptor alleviates TNF-α-induced inflammation through inhibition of the NF-κB signaling pathway in human colonic epithelial cells

To investigate the expression of adenosine A3 receptor (A3AR) in human colonic epithelial cells and the effects of A3AR activation on tumor necrosis factor alpha (TNF-α-) induced inflammation in order to determine its mechanism of action in human colonic epithelial cells, human colonic epithelial cells (HT-29 cells) were treated with different concentrations of 2-Cl-IB-MECA prior to TNF-α stimulation, followed by analysis of NF-κB signaling pathway activation and downstream IL-8 and IL-1β production. A3AR mRNA and protein were expressed in HT-29 cells and not altered by changes in TNF-α or 2-Cl-IB-MECA. Pretreatment with 2-Cl-IB-MECA prior to stimulation with TNF-α attenuated NF-κB p65 nuclear translocation as p65 protein decreased in the nucleus of cells and increased in the cytoplasm, inhibited the degradation of IκB-α, and reduced phosphorylated-IκB-α level significantly, compared to TNF-α-only-treated groups. Furthermore, 2-Cl-IB-MECA significantly decreased TNF-α-stimulated IL-8 and IL-1β mRNA expression and secretion, compared to the TNF-α-only treated group. These results confirm that A3AR is expressed in human colonic epithelial cells and demonstrate that its activation has an anti-inflammatory effect, through the inhibition of NF-κB signaling pathway, which leads to inhibition of downstream IL-8 and IL-1β expression. Therefore, A3AR activation may be a potential treatment for gut inflammatory diseases such as inflammatory bowel disease.

Intervention effect of Compound Sophorae Flavescentis decoction on DOR-β-arrestin1-Bcl-2 signal transduction pathway in rats with ulcerative colitis

AIM: To explore the intervention effect of Compound Sophorae Flavescentis decoction on the DOR-β-arrestin1-Bcl-2 signal transduction pathway in rats with ulcerative colitis.

METHODS: Eighty-four Sprague-Dawley rats were equally and randomly divided into normal control group, model group, mesalazine group, high-, medium-, and low-dose Compound Sophorae Flavescentis decoction groups. Except for the normal control group, ulcerative colitis was induced with trinitrobenzene sulfonic acid (TNBS) in rats of other groups. After induction of ulcerative colitis, bloody stools, mental state and diarrhea were observed and recorded daily. Two rats in the model group were randomly selected and executed on day 3 for observing pathological changes in the colon tissue. Rats in the mesalazine group and Compound Sophorae Flavescentis decoction groups were lavaged with mesalazine solution and Compound Sophorae Flavescentis decoction for 15 d, while those in the normal control group and model group were given equal volume of distilled water for the same duration. On day 16, the remaining rats were executed to detect histopathological changes in the colon tissue and the mRNA and protein expression of DOR, β-arrestin1 and Bcl-2 in the colon tissue by real-time PCR and immunohistochemistry, respectively.

RESULTS: The mRNA and protein expression of DOR, β-arrestin1 and Bcl-2 differed significantly among each group (P < 0.05). Compared to the normal control group, the mRNA and protein expression of DOR, β-arrestin1 and Bcl-2 protein was significantly increased (24.11 ± 12.61 vs 11.88 ± 5.90, 38.90 ± 5.30 vs 14.34 ± 8.97, 23.57 ± 9.96 vs 9.68 ± 3.94, all P < 0.05) in the colon mucosa in the model group. Compared to the model group, the mRNA and protein expression of DOR, β-arrestin1 and Bcl-2 in the colon mucosa was significantly decreased in the mesalazine group and Compound Sophorae Flavescentis decoction groups; however, the mRNA and protein expression of DOR, β-arrestin1 and Bcl-2 did not differ significantly between the mesalazine group and Compound Sophorae Flavescentis decoction groups.

CONCLUSION: The expression of DOR, β-arrestin1 and Bcl-2 is elevated in ulcerative colitis. The DOR-β-arrestin1-Bcl-2 signal transduction pathway may be involved in the pathogenesis of ulcerative colitis, and Compound Sophorae Flavescentis decoction may have a significant therapeutic effect against ulcerative colitis.

Protective effect of naringenin against experimental colitis via suppression of Toll-like receptor 4/NF-κB signalling

Naringenin, one of the most abundant flavonoids in citrus, grapefruits and tomatoes, has been used as a traditional anti-inflammatory agent for centuries. However, the molecular mechanism of naringenin in intestinal inflammation remains unknown so far. The present study investigated a molecular basis for the protective effect of naringenin in dextran sulphate sodium-induced murine colitis. Pre-administration of naringenin significantly reduced the severity of colitis and resulted in down-regulation of pro-inflammatory mediators (inducible NO synthase (iNOS), intercellular adhesion molecule-1 (ICAM-1), monocyte chemoattractant protein-1 (MCP-1), cyclo-oxygenase-2 (Cox2), TNF-α and IL-6 mRNA) in the colon mucosa. The decline in the production of pro-inflammatory cytokines, specifically TNF-α and IL-6, correlated with a decrease in mucosal Toll-like receptor 4 (TLR4) mRNA and protein. Phospho-NF-κB p65 protein was significantly decreased, which correlated with a similar decrease in phospho-IκBα protein. Consistent with the in vivo results, naringenin exposure blocked lipopolysaccharide-stimulated nuclear translocation of NF-κB p65 in mouse macrophage RAW264.7 cells. In addition, in vitro NF-κB reporter assays performed on human colonic HT-29 cells exposed to naringenin demonstrated a significant inhibition of TNF-α-induced NF-κB luciferase expression. Thus, for the first time, the present study indicates that targeted inhibition of the TLR4/NF-κB signalling pathway might be an important mechanism for naringenin in abrogating experimental colitis.

Progress in understanding the role of interleukins in the pathogenesis of ulcerative colitis

Ulcerative colitis (UC) is a chronic, nonspecific inflammatory bowel disease. The assessment of UC reactiveness can be used to guide clinical treatment. Therefore, it is of important significance to find markers which have sufficient specificity and sensitivity for ease of monitoring UC. In recent years, a intensive study of the relation between interleukins (ILs) and the pathogenesis of UC has revealed changes in the secretion levels of ILs in the progression of UC, which suggests that ILs can be used as markers for monitoring the activity of UC to guide diagnosis and treatment. This paper is a review on the mechanism of action of ILs in the pathogenesis of UC.

Wumeiwan treatment alters the expression of β2AR, β-arrestin 2 and NF-κB p65 in rat ulcerative colitis

AIM: To investigate the effects of Wumeiwan treatment on the expression of β2-adrenergic receptor (β2AR), β-arrestin 2, NF-κB p65 in ulcerative colitis in rats.

METHODS: Sprague-Dawley rats were randomly divided into four groups: control group, model group, mesalazine group and Wumeiwan group. Ulcerative colitis was induced in rats with 2, 4, 6-trinitrobenzenesulfonic acid. The control group and model group were administered intragastrically with 3 mL of normal saline, while the mesalazine group and Wumeiwan group were intragastrically given mesalazine at a dose of 50 mg/100 g body weight and 3 mL of Wumeiwan (0.515 g/mL), respectively. All rats were treated for 15 d. Spleen and colon tissue samples were taken to detect the expression of β2AR, β-arrestin 2 and NF-κB p65 by Western blot and immunohistochemistry.

RESULTS: The expression levels of β2AR and β-arrestin 2 were significantly lower in the model group than in the control group (12.54% ± 1.28% vs 15.28% ± 1.71%, 12.67% ± 1.42% vs 15.28% ± 1.58%). Treatment with either Wumeiwan or mesalazine significantly increased the expression of β2AR and β-arrestin 2 (16.27% ± 1.40%, 16.18% ± 1.12%; 17.05% ± 1.48%, 16.77% ± 1.40%), and there were no significant differences in the expression levels of β2AR and β-arrestin 2 between the Wumeiwan and mesalazine groups. The expression level of NF-κB p65 was significantly higher in the model group than in the control group (17.79% ± 1.24% vs 13.82% ± 1.13%). Treatment with either Wumeiwan or mesalazine significantly decreased the expression of NF-κB p65 (16.61% ± 1.42%, 15.39% ± 1.21%), and there was no significant difference in the expression level of NF-κB p65 between the Wumeiwan and mesalazine groups.

CONCLUSION: Both Wumeiwan and mesalazine have significant efficacy in the treatment of ulcerative colitis in rats.