Polynitroxylated starch/TPL attenuates cachexia and increased epithelial permeability associated with TNBS colitis

High-throughput omics technologies in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic, relapsing intestinal disease. Elucidation of the pathogenic mechanisms of IBD requires high-throughput technologies (HTTs) to effectively obtain and analyze large amounts of data. Recently, HTTs have been widely used in IBD, including genomics, transcriptomics, proteomics, microbiomics, metabolomics and single-cell sequencing. When combined with endoscopy, the application of these technologies can provide an in-depth understanding on the alterations of intestinal microbe diversity and abundance, the abnormalities of signaling pathway-mediated immune responses and functionality, and the evaluation of therapeutic effects, improving the accuracy of early diagnosis and treatment of IBD. This review comprehensively summarizes the development and advancement of HTTs, and also highlights the challenges and future directions of these technologies in IBD research. Although HTTs have made striking breakthrough in IBD, more standardized methods and large-scale dataset processing are still needed to achieve the goal of personalized medicine.

Progress and prospects of modified starch-based carriers in anticancer drug delivery

Recently, the role of starch-based carrier systems in anticancer drug delivery has gained considerable attention. Although there are same anticancer drugs, difference in their formulations account for unique therapeutic effects. However, the exploration on the effect-enhancing of anticancer drugs and their loading system by modified starch from the perspective of carrier regulation is still limited. Moreover, research on the reduced toxicity of the anticancer drugs due to modified starch as the drug carrier mediated by the intestinal microenvironment is lacking, but worth exploring. In this review, we examined the effect of modified starch on the loading and release properties of anticancer drugs, and the effect of resistant starch and its metabolites on intestinal microecology during inflammation. Particularly, the interactions between modified starch and drugs, and the effect of resistant starch on gene expression, protein secretion, and inflammatory factors were discussed. The findings of this review could serve as reference for the development of anticancer drug carriers in the future.

A study of the damage of the intestinal mucosa barrier structure and function of Ctenopharyngodon idella with Aeromonas hydrophila

The aim of this study is to explore the effect of Aeromonas hydrophila on the intestinal mucosal barrier structure and intestinal permeability in grass carp (Ctenopharyngodon idella). Histopathological examinations showed that A. hydrophila induced severe intestinal lesions, including inflammatory cell infiltration and intestinal villus fusion and swelling. Messenger RNA (mRNA) expression of the inflammatory cytokines TNF-α, IL-1β, IL-8, IL-10 and MyD88 was significantly increased after infection with A. hydrophila. The permeability of intestinal mucosa was determined using Evans blue (EB) and D-lactic acid. The results indicated that the levels of EB and serum D-lactic acid were significantly increased after infection with A. hydrophila (p < 0.05). Our results also indicated that the intestinal mucosal barrier injury induced by A. hydrophila infection was closely associated with the expression of the tight junction (TJ) protein zonula occludens-1 (ZO-1), occludin, claudin b and claudin c as well as the activity of Na⁺, K⁺-ATPase and Ca²⁺, Mg²⁺-ATPase. Lower mRNA levels of occludin and lower Na⁺, K⁺-ATPase and Ca²⁺, Mg²⁺-ATPase activity in the intestines were observed after challenge. ZO-1 and claudin c were significantly increased 24 h after infection with A. hydrophila. The most interesting finding was that claudin b also significantly increased 24 h after challenge and then decreased to lower levels at 72, 120 and 168 h post-infection compared to the PBS-treated control group. The results demonstrated that grass carp infection with A. hydrophila induced intestinal inflammation and impaired the structure and function of the intestinal mucosal barrier.

Nutrition Modulation of Cachexia/Proteolysis

Cachexia represents progressive wasting of muscle and adipose tissue and is associated with increased morbidity and mortality. Although anorexia usually accompanies cachexia, cachexia rarely responds to increased food intake alone. Our knowledge of the underlying mechanisms responsible for cachexia remains incomplete. However, most states of cachexia are associated with underlying inflammatory processes and/or cancer. These processes activate protein degradation and lipolytic pathways, resulting in tissue loss. In this article, we briefly review the pathophysiology of cachexia and discuss the role of specific nutrient supplements for the treatment of cachexia. The branched chain amino acid leucine, the leucine metabolite beta-hydroxy-beta-methylbutyrate, arginine, glutamine, omega-3 long chain fatty acids, conjugated linoleic acid, and polyphenols have demonstrated some efficacy in animal and/or human studies. Optimal treatment for cachexia is likely aimed at maximizing muscle and adipose synthesis while minimizing degradation.

Heme degradation and vascular injury

Heme is an essential molecule in aerobic organisms. Heme consists of protoporphyrin IX and a ferrous (Fe(2+)) iron atom, which has high affinity for oxygen (O(2)). Hemoglobin, the major oxygen-carrying protein in blood, is the most abundant heme-protein in animals and humans. Hemoglobin consists of four globin subunits (alpha(2)beta(2)), with each subunit carrying a heme group. Ferrous (Fe(2+)) hemoglobin is easily oxidized in circulation to ferric (Fe(3+)) hemoglobin, which readily releases free hemin. Hemin is hydrophobic and intercalates into cell membranes. Hydrogen peroxide can split the heme ring and release "free" redox-active iron, which catalytically amplifies the production of reactive oxygen species. These oxidants can oxidize lipids, proteins, and DNA; activate cell-signaling pathways and oxidant-sensitive, proinflammatory transcription factors; alter protein expression; perturb membrane channels; and induce apoptosis and cell death. Heme-derived oxidants induce recruitment of leukocytes, platelets, and red blood cells to the vessel wall; oxidize low-density lipoproteins; and consume nitric oxide. Heme metabolism, extracellular and intracellular defenses against heme, and cellular cytoprotective adaptations are emphasized. Sickle cell disease, an archetypal example of hemolysis, heme-induced oxidative stress, and cytoprotective adaptation, is reviewed.

Balsalazine decreases intestinal mucosal permeability of dextran sulfate sodium-induced colitis in mice

AIM

To investigate the effect of balsalazine treatment on intestinal mucosal permeability in dextran sulfate sodium (DSS)-induced colitis and to determine the mechanism of the balsalazine-induced changes.

METHODS

Experimental colitis was induced in C57BL/6J mice by the administration of 5% DSS. Balsalazine was administered intragastrically at doses of 42, 141, and 423 mg/kg. The disease activity index (DAI) score was evaluated and colon tissue was collected for the assessment of histological changes. The amount of malondialdehyde (MDA) in the colon was determined, along with the activity of myeloperoxidase (MPO), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px). Mucosa from the small intestine was collected to determine the levels of tumor necrosis factor (TNF)-alpha and interferon (IFN)-gamma. The mucosa was ultrastructurally examined with transmission electron microscopy and intestinal permeability was assayed using Evans blue.

RESULTS

Balsalazine was found to reduce the DAI score and the histological index (HI) score, decrease the MDA content and the activity of MPO, and increase the activity of SOD and GSH-Px in colitis mice. At the same time, balsalazine ameliorated microvillus and tight junction structure, resulting in a decrease in the amount of Evans blue permeating into the intestinal wall and the levels of TNF-alpha and IFN-gamma in colitis mice.

CONCLUSION

In colitis mice, the anti-colitis effect of balsalazine results in a decrease in intestinal mucosal permeability. The mechanism of this effect is partly associated with balsalazine's antioxidative and anti-inflammatory effects.Acta Pharmacologica Sinica (2009) 30: 987-993; doi: 10.1038/aps.2009.77.

Anti-Siglec-F antibody inhibits oral egg allergen induced intestinal eosinophilic inflammation in a mouse model

Siglec-F is a sialic acid binding immunoglobulin-superfamily receptor that is highly expressed on eosinophils. We have used a mouse model of oral egg ovalbumin (OVA)-induced eosinophilic inflammation of the gastro-intestinal mucosa associated with diarrhea and weight loss to determine whether administering an anti-Siglec-F antibody would reduce levels of intestinal mucosal eosinophilic inflammation. Mice administered the anti-Siglec-F antibody had significantly lower levels of intestinal eosinophilic inflammation, and this was associated with reduced intestinal permeability changes, normalization of intestinal villous crypt height, and restoration of weight gain. The reduced numbers of intestinal eosinophils in anti-Siglec-F antibody treated mice was associated with significantly reduced numbers of bone marrow and peripheral blood eosinophils, but was not associated with significant changes in the numbers of proliferating or apoptotic jejunal eosinophils. In addition, the anti-Siglec-F Ab reduced Th2 cytokines and IgE levels. Overall, these studies demonstrate that administration of an anti-Siglec-F antibody significantly reduces levels of eosinophilic inflammation in the intestinal mucosa and that this was associated with reduced intestinal permeability changes, normalization of intestinal villous crypt height, and restoration of weight gain.

Inflammatory bowel disease and the apical junctional complex

A critical function of the intestinal mucosa is to form a barrier that separates luminal contents from the underlying interstitium. This intestinal barrier is primarily regulated by the apical junctional complex (AJC) consisting of tight junctions (TJs) and adherens junctions (AJs) and is compromised in a number of intestinal diseases, including inflammatory bowel disease (IBD). In vitro studies have demonstrated that proinflammatory cytokines, such as interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha), that are increased in the intestinal mucosa of patients with IBD can induce a leaky mucosal barrier. There is a growing evidence that the increased permeability and altered AJC structure observed in IBD are mediated by internalization of junctional proteins. This review summarizes barrier defects observed in IBD and addresses mechanisms by which proinflammatory cytokines, such as IFN-gamma and TNF-alpha, modulate AJC structure and epithelial barrier function.

Polynitroxyl albumin inhibits inflammation and vasoocclusion in transgenic sickle mice

Individuals with sickle-cell disease (SCD) and transgenic sickle mice expressing human betaS globin exhibit enhanced reactive oxygen species (ROS) production, vascular inflammation, and episodic vasoocclusion. We hypothesize that reduction of ROS will reduce endothelial-cell activation and adhesion-molecule expression, thereby inhibiting vasoocclusion. To test this hypothesis, we measured endothelial-cell activation, adhesion-molecule expression, and vasoocclusion in sickle mice after administering i.v. polynitroxyl albumin (PNA), a superoxide dismutase and catalase mimetic. Untreated sickle mice, compared with normal mice, showed increased activation of nuclear factor-kappaB (NF-kappaB), an oxidant-sensitive transcription factor, in their lungs, livers, and skin. NF-kappaB activation was increased further in the livers and skin of sickle but not normal mice after hypoxia-reoxygenation. IV administration of PNA inhibited NF-kappaB activation by 60% (P < .01) in the lungs and by 33% (P < .05) in the livers of sickle mice after hypoxia-reoxygenation. PNA also reduced the expression of vascular cell-adhesion molecule-1 (VCAM-1) by 57% in lung (P < .05) and by 33% in liver (P < .05) and reduced the expression of intercellular-adhesion molecule-1 (ICAM-1) by 40% in lung (P < .05) and by 53% in liver (P < .05). PNA inhibited a hypoxia-reoxygenation-induced increase in leukocyte rolling (P < .01) and adhesion (P < .05) in venules of the dorsal skin. Most importantly, PNA completely inhibited hypoxia-reoxygenation-induced vasoocclusion (P < .001). Control albumin had no effect on NF-kappaB, VCAM-1, ICAM-1, rolling, adhesion, or vasoocclusion. We speculate that therapies to reduce oxidative stress will inhibit inflammation and vasoocclusion in SCD.

TNF-alpha -induced endothelial cell adhesion molecule expression is cytochrome P-450 monooxygenase dependent

It is strongly suspected that cytokine-induced gene expression in inflammation is oxidant mediated; however, the intracellular sources of signaling oxidants remain controversial. In inflammatory bowel disease (IBD) proinflammatory cytokines, such as TNF-alpha, trigger gene expression of endothelial adhesion molecules including mucosal addressin cell adhesion molecule-1 (MAdCAM-1). MAdCAM-1 plays an essential role in gut inflammation by governing the infiltration of leukocytes into the intestine. Several groups suggest that endothelial-derived reduced NADP (NADPH) oxidase produces signaling oxidants that control the expression of adhesion molecules (E-selectin, ICAM-1, VCAM-1). In addition to NADPH oxidase, cytochrome P-450 (CYP450) monooxygenases have also been shown to trigger cytokine responses. We found that in high endothelial venular cells (SVEC4-10), multiple inhibitors of CYP450 monooxygenases (SKF-525a, ketoconazole, troleandomycin, itraconazole) attenuated TNF-alpha induction of MAdCAM-1, whereas NADPH oxidase inhibition (PR-39) did not. Conversely, E-selectin, ICAM-1, and VCAM-1 induction requires both NADPH oxidase and CYP450-derived oxidants. We show here that MAdCAM-1 induction may depend exclusively on CYP450-derived oxidants, suggesting that CYP450 blockers might represent a possible novel therapeutic treatment for human IBD.