Docosahexaenoic Acid Attenuated Experimental Chronic Colitis in Interleukin 10-Deficient Mice by Enhancing Autophagy Through Inhibition of the mTOR Pathway.

BACKGROUND: In the battle against Crohn's disease, autophagy stimulation is a promising therapeutic option-one both new and newly rediscovered. In experimental models, docosahexaenoic acid (DHA)-a long-chain polyunsaturated fatty acid-has been demonstrated to be useful in the treatment of inflammatory bowel disease through inhibition of the nuclear factor-κB pathway. However, the impact of DHA on autophagy in the colon remains unclear. METHODS: Mice were divided into 3 groups: wild type (placebo), the interleukin 10 knockout group (IL-10-/-, placebo), and the DHA group (IL-10-/-, DHA). DHA was administered to IL-10-/- mice by gavage at a dosage of 35.5 mg/kg/d for 2 weeks. The severity of colitis, expression of proinflammatory cytokines, expression/distribution of LC3B, and mTOR signaling pathway were evaluated in the proximal colon tissues collected from all mice at the end of the experiment. RESULTS: DHA administration ameliorated experimental colitis in the IL-10-/- mice, as demonstrated by decreased proinflammatory cytokines (TNF-α and IFN-γ), reduced infiltration of inflammatory cells, and lowered histologic scores of the proximal colon mucosa. Moreover, in the DHA-treated mice, enhanced autophagy was observed to be associated with (1) increased expression and restoration of the distribution integrity of LC3B in the colon and (2) inhibition of the mTOR signaling pathway. CONCLUSION: This study showed that DHA therapy could attenuate experimental chronic colitis in IL-10-/- mice by triggering autophagy via inhibition of the mTOR pathway.

DHA protects against experimental colitis in IL-10-deficient mice associated with the modulation of intestinal epithelial barrier function.

A defect in the intestinal barrier is one of the characteristics of Crohn's disease (CD). The tight junction (TJ) changes and death of epithelial cells caused by intestinal inflammation play an important role in the development of CD. DHA, a long-chain PUFA, has been shown to be helpful in treating inflammatory bowel disease in experimental models by inhibiting the NF-κB pathway. The present study aimed at investigating the specific effect of DHA on the intestinal barrier function in IL-10-deficient mice. IL-10-deficient mice (IL-10(-/-)) at 16 weeks of age with established colitis were treated with DHA (i.g. 35.5 mg/kg per d) for 2 weeks. The severity of their colitis, levels of pro-inflammatory cytokines, epithelial gene expression, the distributions of TJ proteins (occludin and zona occludens (ZO)-1), and epithelial apoptosis in the proximal colon were measured at the end of the experiment. DHA treatment attenuated the established colitis and was associated with reduced infiltration of inflammatory cells in the colonic mucosa, lower mean histological scores and decreased levels of pro-inflammatory cytokines (IL-17, TNF-α and interferon-γ). Moreover, enhanced barrier function was observed in the DHA-treated mice that resulted from attenuated colonic permeability, rescued expression and corrected distributions of occludin and ZO-1. The results of the present study indicate that DHA therapy may ameliorate experimental colitis in IL-10(-/-) mice by improving the intestinal epithelial barrier function.

Celastrol ameliorates experimental colitis in IL-10 deficient mice via the up-regulation of autophagy.

BACKGROUND: Celastrol had been proved effective in the treatment for IBD, probably with the modulation of oxidative stress, inflammatory cytokines and intestinal homeostasis. This study was aimed to investigate whether celastrol could ameliorate the inflammation of IL-10 deficient mice, a murine model of Crohn's disease (CD) with the induction of autophagy. MATERIAL AND METHODS: The mice included were divided into four groups, ##WT group, IL-10(-/-) group, Cel group and Control group (celastrol+3-Methyladenine). Celastrol (2 mg/kg) treatment by gavage was administered to mice daily over one week. 3-Methyladenine (autophagy inhibitors) was administered at a dose of 30 mg/kg by intraperitoneal injection. The histological evaluation of the colon, tissue myeloperoxidase (MPO), and colon inflammation of mice in the four groups was evaluated and compared. Furthermore, the PI3K/Akt/mTOR pathway and the status of autophagy in intestine affected by celastrol were also assessed. RESULTS: The one-week administration of celastrol ameliorated established colitis in IL-10 deficient mice, associated with a reduction of marked histological inflammation, a decreased colon MPO concentration and suppression of colonic proinflammatory cytokine. Furthermore, the decreased neutrophil infiltration in proximal colon and improvement of inflammation in the Cel group was much more obvious than that in the Control group. The Western blotting analysis of the PI3K/Akt/mTOR pathway and autophagy showed that celastrol treatment up-regulated the autophagy of colon tissue by suppressing the PI3K/Akt/mTOR signaling pathway. CONCLUSIONS: Celastrol ameliorates experimental colitis in IL-10 deficient mice via the up-regulation of autophagy by suppressing the PI3K/Akt/mTOR signaling pathway.

Effectiveness of a clinical pathway for inpatients undergoing ileal/ileocecal resection for chronic radiation enteritis with intestinal obstruction.

Surgery is associated with elevated morbidity and mortality in chronic radiation enteritis (CRE). The objective of this study was to evaluate the effect of a fast-track clinical pathway (CP) on postoperative outcomes in patients undergoing ileal/ileocecal resection for CRE with intestinal obstruction. There were 85 patients with CRE (January 2011 to March 2013) with intestinal obstruction admitted to our department for ileal/ileocecal resection. The patients were divided into a prepathway group and a pathway group. The clinical outcomes were then assessed and compared. The postoperative lengths of hospital stay were 8.52 days for the pathway group and 11.32 days for the prepathway group (P = 0.02). The pathway group had a lower stoma rate (21.6 vs 56%, P = 0.033) and fewer postoperative moderate to severe complications (8.1 vs 25%, P = 0.043) compared with the prepathway group. Implementation of the CP may reduce stoma rate, postoperative moderate to severe complications, and postoperative length of hospital stay for patients undergoing ileal/ileocecal resection for the treatment of CRE with intestinal obstruction.

Impact of enteral nutrition on energy metabolism in patients with Crohn's disease.

AIM: To investigate the impact of enteral nutrition (EN) on the body composition and metabolism in patients with Crohn's disease (CD). METHODS: Sixty-one patients diagnosed with CD were enrolled in this study. They were given only EN (enteral nutritional suspension, TPF, non-elemental diet) support for 4 wk, without any treatment with corticosteroids, immunosuppressive drugs, infliximab or by surgical operation. Body composition statistics such as weight, body mass index, skeletal muscle mass (SMM), fat mass, protein mass and inflammation indexes such as C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) and CD activity index (CDAI) were recorded before and after EN support. RESULTS: The 61 patients were divided into three groups according to CDAI before and after EN support: A (active phase into remission via EN, n=21), B (remained in active phase before and after EN, n=19) and C (in remission before and after EN, n=21). Patients in group A had a significant increase in SMM (22.11±4.77 kg vs 23.23±4.49 kg, P=0.044), protein mass (8.01±1.57 kg vs 8.44±1.45 kg, P=0.019) and decrease in resting energy expenditure (REE) per kilogram (27.42±5.01 kcal/kg per day vs 22.62±5.45 kcal/kg per day, P<0.05). There was no significant difference between predicted and measured REE in active CD patients according to the Harris-Benedict equation. There was no linear correlation between the measured REE and CRP, ESR or CDAI in active CD patients. CONCLUSION: EN could decrease the hypermetabolism in active CD patients by reducing the inflammatory response.