Qiao Mei

Myosin Light Chain Kinase Inhibitor Inhibits Dextran Sulfate Sodium-Induced Colitis in Mice

Background and AimsMyosin light chain kinase (MLCK) plays a central role in the mechanisms of barrier dysfunction, and intestinal epithelial MLCK protein expression is upregulated in active ulcerative colitis (UC). ML-7, a MLCK inhibitor, has been used in many MLCK studies. However, the effect of ML-7 has never been estimated in colitis models. The aim of this study was to determine whether ML-7 can treat UC.MethodsExperimental colitis was induced and ML-7 was administered by intraperitoneal injection. The disease activity index (DAI) scores were evaluated and colon tissue was collected for the assessment of histological changes, myeloperoxidase (MPO) activity, and tumor necrosis factor (TNF)-α, interferon (IFN)-γ, interleukin (IL)-13 and interleukin (IL)-17 levels. The small intestinal mucosa was ultrastructurally examined, epithelial MLCK protein expression and enzymatic activity were determined, and intestinal permeability was assayed using FITC-dextran 4000 (FD-4) and Evans blue (EB).ResultsML-7 was found to be significantly effective in reducing the DAI scores and histological index scores, and decreasing MPO activity and TNF-α, IFN-γ, IL-13 and IL-17 levels. The small intestinal epithelial MLCK protein expression and enzymatic activity were downregulated by ML-7. The epithelial cells and intercellular tight junctions were ameliorated, and the amount of FD-4 in blood and EB permeating into the intestine were decreased by ML-7 in colitis mice.ConclusionsML-7 has a significant anti-colitis effect in colitis mice. It is mainly associated with the inhibition of the epithelial MLCK protein expression, resulting in ameliorated intestinal mucosal permeability.

Effect of homocysteine on intestinal permeability in rats with experimental colitis, and its mechanism

Objective: To investigate the effect of homocysteine (Hcy) on intestinal permeability in rats with TNBS/ethanol-induced colitis and elucidate its mechanism. Methods: Sprague-Dawley rats were divided into four groups: normal, normal + Hcy injection, TNBS model, and TNBS model + Hcy injection. Experimental colitis was induced by trinitrobenzene sulfonic acid (TNBS) in 50% ethanol; rats were injected subcutaneously with Hcy from the first day after the induction of experimental colitis on 30 consecutive days. To determine the severity of colitis, the disease activity index (DAI) was evaluated; colon tissues were collected for the detection of the activity of myeloperoxidase (MPO) and the contents of MDA, IL-1β, IL-6, TNF-α, MMP-2, and MMP-9. Intestinal epithelial permeability was assessed with Evans blue (EB) dye. The levels of Hcy in plasma and colon mucosa were measured by high-performance liquid chromatography-fluorescence detection (HPLC-FD). Results: Compared with the normal group, the DAI scoring and MPO activity, contents of MDA, IL-1β, IL-6, TNF-α, MMP-2, MMP-9 in the colon and EB in the small intestine were significantly increased in the TNBS group (P < 0.01). Compared with the TNBS model group, the DAI scoring, plasma and colonic mucosa Hcy levels, MPO activity and contents of MDA, IL-1β, IL-6, TNF-α, MMP-2, MMP-9 in colon and EB in small intestine were significantly increased in the TNBS-induced colitis rats with simultaneous Hcy injection (P < 0.01). Conclusion: Hcy can increase intestinal permeability and aggravate inflammatory damage in rats with TNBS-induced colitis, the underlying mechanisms of which may be attributed to its effects of promoting the expression of MMP-2 and MMP-9, leading to injury of the intestinal barrier.

Measurement of red blood cell 6-thioguanine nucleotide is beneficial in azathioprine maintenance therapy of Chinese Crohn’s disease patients

Abstract Objective: It remains controversial whether 6-thioguanine nucleotide (6-TGN)-based dose adjusting can be beneficial in azathioprine (AZA) therapy. This study is designed to assess the role of 6-TGN concentrations in maintaining clinical remission in Chinese patients with Crohn’s disease (CD). Material and method: We performed a prospective observational study and collected data of CD patients in the First Affiliated Hospital of Anhui Medical University from June 2013 to April 2014. Demographic material, CD activity index, 6-TGN concentration, and laboratory tests were recorded at baseline and at each visit. In addition, 6-TGN was measured when drug adverse effects occurred. All patients achieved maintenance stage were administered a stable AZA dose at least 3 months before enrollment and were followed up at least 12 months. Thiopurine S-methyltransferase (TPMT) genotype was measured before AZA treatment. Results: Sixty-nine patients receiving maintenance therapy were analyzed. A positive correlation was found between 6-TGN levels and AZA dose (r = 0.258, p = 0.032). The mean 6-TGN concentration was 302.06 ± 115.84 in the remission group vs. 264.94 ± 164.53 pmol/8 × 108 RBC in those with active disease (t = 0.847, p = 0.40), and 197.74 ± 66.54 pmol/8 × 108 RBC in patients who relapsed vs. 310.26 ± 122.38 pmol/8 × 108 RBC for those in sustained remission (t= −2.541, p = 0.013). In the leukopenia group, the 6-TGN concentration was 469.11 ± 115.53 pmol/8 × 108 RBC vs. 257.31 ± 83.74 pmol/8 × 108 RBC in the non-leukopenia group (t = 7.622, p < 0.001). There was a significant negative correlation between leukocyte count and 6-TGN concentration (r= −0.326, p = 0.006). Conclusions: 6-TGN measurement is a helpful method of preventing disease relapse and avoiding leukopenia in individual azathioprine maintenance therapy.

Early predictors of responses and clinical outcomes of corticosteroid treatment for severe ulcerative colitis.

Abstract Background. Patients with severe ulcerative colitis (SUC) have a high risk of requiring colectomy or resorting to a second-line treatment. However, neither clinical outcomes nor factors predictive of poor response have been clearly established in the treatment of SUC. Objective. To assess prospectively the effects and predictors of corticosteroids (CS) use in clinical outcomes of SUC during 1 year of follow-up. Material and methods. Consecutive inpatients with SUC, who had been treated with intravenous CS, were enrolled. Patients were monitored by clinical, laboratory, and endoscopic examinations, and the data were recorded for 1 year. Univariate and multivariate analyses were performed at 1 week. Results. There were 22.6% (14/62) nonresponders at 7 days. Several predictors were associated with nonresponse to CS. These included Mayo Score at baseline (p = 0.007), partial Mayo Score, number of bowel movements, blood presence in stool, abdominal pain, and levels of C-reactive protein (CRP), hemoglobin (Hgb), platelet count (PLT), and erythrocyte sedimentation rate (ESR) on day 3 (p < 0.05). Multiple logistic regression analysis identified the Partial Mayo Score at day 3 as an independent predictor of outcome (p = 0.012). A total of 12 patients underwent colectomy within 1 year. The short-term response rates to intravenous cyclosporin (CsA) and infliximab (IFX) in SUC were 71.4% (5/7) and 77.8% (7/9), respectively. Conclusions. Many patients with SUC eventually became refractory to or dependent on CS. The Mayo score and laboratory characteristics were factors useful in predicting short-term outcome of CS treatment. Secondary medical therapy can help avoid emergency surgery.

Resolvin D1 Resolve Inflammation in Experimental Acute Pancreatitis by Restoring Autophagic Flux

BackgroundAcute pancreatitis (AP) is a common acute gastrointestinal disorders. Increasing evidence indicated that autophagy is involved in the development of AP. Resolvin D1 is an endogenous pro-resolving lipid mediator, which can protect mice from cerulein-induced acute pancreatitis and facilitate autophagy in macrophage, but its mechanism remians unclear.AimsTo investigate the effect of resolvin D1 on autophagy in mouse models of cerulein-induced AP.MethodsC57BL/6 mice were randomly divided into control group, AP group and resolvin D1 group. The models of cerulein-induced AP were constructed by intraperitoneally cerulein. Resolvin D1 group was established by intraperitoneally resolvin D1 based on AP models, simultaneously, control group received normal saline. The severity of AP, the level of inflammatory cytokines, the number of autophagic vacuoles, and the expression of autophagy-related markers were evaluated among three groups.ResultsThe AP models were established successfully. Compared to control group, the number of autophagic vacuoles and expressions of autophagy-related markers including Beclin-1, p62 and LC3-II were increased in AP models, In contrast, the degree of inflammation and levels of inflammatory cytokines in AP models were reduced after resolvin D1 treatment. Moreover, resolvin D1 attenuated the number of autophagic vacuoles and expressions of autophagy-related markers.ConclusionsAutophagic flux is impaired in cerulein-induced AP. Resolvin D1 ameliorate the severity of mice with cerulein-induced acute pancreatitis, possible attributing to its reducing impaired autophagy and restoring autophagic flux.