The appendix orchestrates T-cell mediated immunosurveillance in colitis-associated cancer

Objective. While appendectomy may reduce colorectal inflammation in patients with ulcerative colitis (UC), appendectomy has been suggested to be associated with an increased risk of colitis-associated cancer (CAC). The aim of this study was to explore the mechanism underlying the appendectomy-associated increased risk of CAC. Design. Five-week-old male BALB/c mice underwent appendectomy, appendicitis induction or sham laparotomy. They were then exposed to azoxymethane/dextran sodium sulfate (AOM/DSS) to induce CAC. Mice were sacrificed 12 weeks later, and colons were taken for pathological analysis and immunohistochemistry (CD3 and CD8 staining). Human colonic tumors from 21 UC patients who underwent surgical resection for CAC were immunophenotyped and stratified according to the appendectomy status. Results. While appendectomy significantly reduced colitis severity and increased CAC number, appendicitis induction without appendectomy led to opposite results. Intra-tumor CD3+ and CD8+ T-cell densities were lower after appendectomy and higher after appendicitis induction compared to the sham laparotomy group. Blocking lymphocyte trafficking to the colon with the anti-alpha4-beta7 integrin antibody or a sphingosine-1-phosphate receptor agonist suppressed the inducing effect of the appendectomy on tumors′ number and on CD3+/CD8+ intra-tumoral density. CD8+ or CD3+ T cells isolated from inflammatory neo-appendix and intravenously injected into AOM/DSS-treated recipient mice increased CD3+/CD8+ T-cell tumor infiltration and decreased tumor number. In UC patients with a history of appendectomy, intra-tumor CD3+ and CD8+ T-cell densities were decreased compared to UC patients without history of appendectomy. Conclusions. In UC, appendectomy could suppress a major site of T-cell priming resulting in a less efficient CAC immunosurveillance.

Autophagy Decreases Alveolar Epithelial Cell Injury by Suppressing the NF-κB Signaling Pathway and Regulating the Release of Inflammatory Mediators

To research the impact of autophagy on alveolar epithelial cell inflammation and its possible mechanism in early stages of hypoxia, we established a cell hypoxia-reoxygenation model and orthotopic left lung ischemia-reperfusion model. Rat alveolar epithelial cells stably expressing GFP-LC3 were treated with an autophagy inhibitor (3-methyladenine, 3-MA) or autophagy promoter (rapamycin), followed by hypoxia-reoxygenation treatment at 2, 4 and 6h in vitro. In vivo, twenty-four male Sprague-Dawley rats were randomly divided into four groups (model group: no blocking of hilum in the left lung; control group: blocking of hilum in the left lung for 1h with DMSO lavage; 3-MA group: blocking of hilum in the left lung for 1h with 100ml/kg of 3-MA (5μmol/L) solution lavage; rapamycin group: blocking of hilum in the left lung for 1h with 100ml/kg of rapamycin (250nmol/L) solution lavage) to establish an orthotopic left lung ischemia model. This study demonstrated that rapamycin significantly suppressed the NF-κB signaling pathway, restrained the expression of pro-inflammatory factors. A contrary result was confirmed by 3-MA pretreatment. These findings indicate that autophagy reduces ischemia-reperfusion injury by repressing inflammatory signaling pathways in the early stage of hypoxia in vitro and in vivo. This could be a new protective method for lung ischemia-reperfusion injury.

Venezuela institutional conflicts foreshadow dead end

Significance Disputes over constitutionality are tense, and similarly between the executive and legislature, with Maduro preparing to cut funding to the opposition-dominated National Assembly. At the same time, regional pressure is mounting with members of the Mercosur group blocking Venezuela from assuming the body's rotating presidency. Impacts Pressure on the CNE will intensify as the opposition and government respectively seek to advance and block next steps in the recall process. For symbolic reasons, the opposition will keep the Assembly open even if funds are cut and the Supreme Court annuls its initiatives. The dispute with Mercosur will put an already pressured Venezuelan Foreign Ministry on a back foot.