Temporal colonic gene expression profiling in the recurrent colitis model identifies early and chronic inflammatory processes

Desloratadine via its anti-inflammatory and antioxidative properties ameliorates TNBS-induced experimental colitis in rats

BACKGROUND

Intestinal mucosal immune cells, notably mast cells, are pivotal in ulcerative colitis (UC) pathophysiology. Its activation elevates tissue concentrations of histamine. Inhibiting colonic histamine release could be an effective therapeutic strategy for treating UC. Experimental model like 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis in rats mimic human IBD, aiding treatment investigations. Drug repurposing is a promising strategy to explore new indications for established drugs. Desloratadine (DES) is second-generation antihistamine utilized for managing allergies by blocking histamine action in the body. It also has reported anti-inflammatory and antioxidant actions.

OBJECTIVE

DES was investigated for its repurposing potential in UC by preclinical screening in TNBS-induced colitis in Wistar rats.

METHODS

Therapeutic efficacy of DES was evaluated both individually and in combination with standard drug 5-aminosalicylicacid (5-ASA). Rats were orally administered DES (10 mg/kg), 5-ASA (25 mg/kg), and DES + 5-ASA (5 mg + 12.15 mg) following the induction of colitis. Parameters including disease activity score rate (DASR), colon/body weight ratio (CBWR), colon length, diameter, pH, histological injury, and scoring were evaluated. Inflammatory biomarkers such as IL-1β, TNF-α, along with reduced glutathione (GSH), and malondialdehyde (MDA) were assessed.

RESULTS

Significant protective effects of DES, especially in combination with 5-ASA, against TNBS-induced inflammation were observed as evidenced by reduced DASR, CBWR, and improved colon morphology. Drugs significantly lowered plasma and colon histamine and, cytokines levels. GSH restoration, and decreased MDA content were also observed.

CONCLUSION

DES and DES + 5-ASA demonstrated potential in alleviating colonic inflammation associated with TNBS-induced colitis in rats. The effect can be attributed to its antihistamine, anticytokine, and antioxidative properties.

To die or not to die: Gasdermins in intestinal health and disease

Intestinal homeostasis is achieved by the balance among intestinal epithelium, immune cells, and gut microbiota. Gasdermins (GSDMs), a family of membrane pore forming proteins, can trigger rapid inflammatory cell death in the gut, mainly pyroptosis and NETosis. Importantly, there is increasing literature on the non-cell lytic roles of GSDMs in intestinal homeostasis and disease. While GSDMA is low and PJVK is not expressed in the gut, high GSDMB and GSDMC expression is found almost restrictively in intestinal epithelial cells. Conversely, GSDMD and GSDME show more ubiquitous expression among various cell types in the gut. The N-terminal region of GSDMs can be liberated for pore formation by an array of proteases in response to pathogen- and danger-associated signals, but it is not fully understood what cell type-specific mechanisms activate intestinal GSDMs. The host relies on GSDMs for pathogen defense, tissue tolerance, and cancerous cell death; however, pro-inflammatory milieu caused by pyroptosis and excessive cytokine release may favor the development and progression of inflammatory bowel disease and cancer. Therefore, a thorough understanding of spatiotemporal mechanisms that control gasdermin expression, activation, and function is essential for the development of future therapeutics for intestinal disorders.

Inhibiting sorting nexin 10 promotes mucosal healing through SREBP2-mediated stemness restoration of intestinal stem cells

Intestinal stem cell (ISC) is a promising therapeutic target for inflammatory bowel disease. Cholesterol availability is critical for ISC stemness. Low plasma cholesterol is a typical feature of Crohn's disease (CD); however, its impact on mucosal healing remains unclear. Here, we identified an essential role of sorting nexin 10 (SNX10) in maintaining the stemness of ISCs. SNX10 expression in intestinal tissues positively correlates with the severity of human CD and mouse colitis. Conditional SNX10 knockout in intestinal epithelial cells or ISCs promotes intestinal mucosal repair by maintaining the ISC population associated with increased intracellular cholesterol synthesis. Disassociation of ERLIN2 with SCAP by SNX10 deletion enhances the activation of SREBP2, resulting in increased cholesterol biosynthesis. DC-SX029, a small-molecule inhibitor of SNX10, was used to verify the druggable potential of SNX10 for the treatment of patients with CD. Our study provides a strategy for mucosal healing through SREBP2-mediated stemness restoration of ISCs.

Pre-clinical Investigation of Protective Effect of Nutraceutical D-Glucosamine on TNBS-induced Colitis

The level of precursors involved in the biosynthesis of glycosaminoglycan (GAG), glucosamine synthase, and N-acetyl glucosamine (NAG), are significantly reduced in inflammatory bowel disease (IBD). This results in deficient GAG content in mucosa, which eventually disrupts the gut wall integrity, provoking abnormal immunological responses. This is characterized by colossal liberation of inflammatory mediators including tumor necrosis factor-alpha (TNF-α), interleukins (IL), and reactive oxygen species provoking colonic inflammation. D-glucosamine (D-GLU) is reported to suppress oxidative stress, and pro-inflammatory cytokines and acts as a starting material for biosynthesis of NAG. The potential of D-GLU and its combination with mesalamine (5-ASA) was investigated in 2,4,6-trinitrobenzene sulfonic acid (TNBS)-instigated IBD in Wistar rats. Standard and test drugs were given orally for five days to separate groups of rats. Colonic inflammation was evaluated by disease activity score rate (DASR), colon/body weight ratio, colon length, diameter, colon pH, histological injury and score. Inflammatory biomarkers IL-1β, TNF-α, along with reduced glutathione (GSH), and malondialdehyde (MDA) were assessed. Combination of D-GLU +5-ASA significantly ameliorated severity of colonic inflammation by lowering DASR (P < 0.001) and colon/body weight ratio (P < 0.001), restored the colonic architecture and suppressed the histopathological score (P < 0.001), along with the absence of major adverse reactions. The combination suppressed the levels of inflammatory markers (P < 0.001) and MDA (P < 0.001) while enhancing GSH level (P < 0.001). In comparison to individual 5-ASA and D-GLU, combination of drugs significantly diminished colitis severity through their combined anti-inflammatory and antioxidant effects by acting on multiple targets simultaneously. The combination holds remarkable potential in the management of IBD.

Exploring the Potential of IL-1β Inhibitor Diacerein and its Combination with 5-Aminosalicylic Acid for the Possible Ameliorating Effect in TNBS-induced Experimental Colitis in Wistar Rats

Background:

Pro-inflammatory mediators such as tumor necrosis factor-alpha (TNF-α), interleukin (IL), and oxidative stress are crucial players in the pathophysiology of inflammatory bowel disease (IBD) that contribute in perpetuating intestinal inflammation. Targeting them presents a novel approach in disease management. In the present study, the potential of an antiosteoarthritic IL-inhibitor drug, diacerein (DIA) was investigated in 2, 4, 6-trinitrobenzene sulfonic acid (TNBS)- instigated ulcerative colitis (UC) in Wistar rats. A comparative study was also undertaken to investigate the potential of combination therapy of DIA with the standard drug 5-aminosalicylic acid (5-ASA) versus monotherapy.

Methods:

Colitis was developed by single intra-colonic administration of TNBS (100mg/kg); whereas drugs 5-ASA (25.5 mg/kg), DIA (100 mg/kg), and DIA+5-ASA (100+ 25.5 mg/kg) were administered orally for five days post-induction to various groups of rats. Parameters like disease activity score, colon/body weight ratio, colon length, diameter, gut pH were assessed, and histopathological analysis was carried out. Biochemical markers of colonic inflammation such as IL-1β, TNF-α, reduced glutathione (GSH), and malondialdehyde (MDA) were also estimated.

Results:

Combination of DIA and 5-ASA demonstrated the most significant reduction of the colon to body weight ratio and disease activity score. It prominently restored the colon length, diameter, and gut pH to normal. It attenuated the biochemical alterations induced by TNBS, indicating a highly significant defensive outcome against colonic inflammation. The histopathological report demonstrated the renovating effect of the combination of disrupted colonic histology with minimally distressing liver, stomach, or pancreas compared to individual drugs.

Conclusion:

The combination remarkably downregulated the level of inflammation by suppressing both provocative cytokines and reactive oxygen species production. It can be evaluated further in a clinical setup as a novel and promising drug therapy for UC.

Intraperitoneally Delivered Mesenchymal Stem Cells Alleviate Experimental Colitis Through THBS1-Mediated Induction of IL-10-Competent Regulatory B Cells

Mesenchymal stem cells (MSCs) show promising therapeutic potential in treating inflammatory bowel disease (IBD), and intraperitoneal delivery of MSCs have become a more effective route for IBD treatment. However, the underlying mechanisms are still poorly understood. Here, we found that intraperitoneally delivered MSCs significantly alleviated experimental colitis. Depletion of peritoneal B cells, but not macrophages, clearly impaired the therapeutic effects of MSCs. Intraperitoneally delivered MSCs improved IBD likely by boosting the IL-10-producing B cells in the peritoneal cavity, and a single intraperitoneal injection of MSCs could significantly prevent disease severity in a recurrent mouse colitis model, with lower proinflammation cytokines and high level of IL-10. The gene expression profile revealed that thrombospondin-1 (THBS1) was dramatically upregulated in MSCs after coculture with peritoneal lavage fluid from colitis mice. Knockout of THBS1 expression in MSCs abolished their therapeutic effects in colitis and the induction of IL-10-producing B cells. Mechanistically, THBS1 modulates the activation of transforming growth factor-β (TGF-β), which combines with TGF-β receptors on B cells and contributes to IL-10 production. Blocking the interaction between THBS1 and latent TGF-β or inhibiting TGF-β receptors (TGF-βR) significantly reversed the THBS1-mediated induction of IL-10-producing B cells and the therapeutic effects on colitis. Collectively, our study revealed that intraperitoneally delivered MSCs secreted THBS1 to boost IL-10⁺Bregs and control the progression and recurrence of colitis, providing new insight for the prevention and treatment of IBD.

Epithelial production of elastase is increased in inflammatory bowel disease and causes mucosal inflammation

Imbalance between proteases and their inhibitors plays a crucial role in the development of Inflammatory Bowel Diseases (IBD). Increased elastolytic activity is observed in the colon of patients suffering from IBD. Here, we aimed at identifying the players involved in elastolytic hyperactivity associated with IBD and their contribution to the disease. We revealed that epithelial cells are a major source of elastolytic activity in healthy human colonic tissues and this activity is greatly increased in IBD patients, both in diseased and distant sites of inflammation. This study identified a previously unrevealed production of elastase 2A (ELA2A) by colonic epithelial cells, which was enhanced in IBD patients. We demonstrated that ELA2A hyperactivity is sufficient to lead to a leaky epithelial barrier. Epithelial ELA2A hyperactivity also modified the cytokine gene expression profile with an increase of pro-inflammatory cytokine transcripts, while reducing the expression of pro-resolving and repair factor genes. ELA2A thus appears as a novel actor produced by intestinal epithelial cells, which can drive inflammation and loss of barrier function, two essentials pathophysiological hallmarks of IBD. Targeting ELA2A hyperactivity should thus be considered as a potential target for IBD treatment.

Intestinal Inflammation Modulates the Expression of ACE2 and TMPRSS2 and Potentially Overlaps With the Pathogenesis of SARS-CoV-2-related Disease

BACKGROUND AND AIMS

The presence of gastrointestinal symptoms and high levels of viral RNA in the stool suggest active severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) replication within enterocytes.

METHODS

Here, in multiple, large cohorts of patients with inflammatory bowel disease (IBD), we have studied the intersections between Coronavirus Disease 2019 (COVID-19), intestinal inflammation, and IBD treatment.

RESULTS

A striking expression of ACE2 on the small bowel enterocyte brush border supports intestinal infectivity by SARS-CoV-2. Commonly used IBD medications, both biologic and nonbiologic, do not significantly impact ACE2 and TMPRSS2 receptor expression in the uninflamed intestines. In addition, we have defined molecular responses to COVID-19 infection that are also enriched in IBD, pointing to shared molecular networks between COVID-19 and IBD.

CONCLUSIONS

These data generate a novel appreciation of the confluence of COVID-19- and IBD-associated inflammation and provide mechanistic insights supporting further investigation of specific IBD drugs in the treatment of COVID-19. Preprint doi: https://doi.org/10.1101/2020.05.21.109124.

lncRNACNN3-206 activates intestinal epithelial cell apoptosis and invasion by sponging miR-212, an implication for Crohn's disease

BACKGROUND

Statistics indicate that the incidence of Crohn’s disease (CD) is rising in many countries. The poor understanding on the pathological mechanism has limited the development of effective therapy against this disease. Previous studies showed that long noncoding RNAs (lncRNAs) could be involved in autoimmune diseases including CD, but the detailed molecular mechanisms remain unclear.

AIM

To identify the differentially expressed lncRNAs in the intestinal mucosa associated with CD, and to characterize their pathogenic role(s) and related mechanisms.

METHODS

The differential expression of lncRNAs was screened by high-throughput RNA sequencing, and the top candidate genes were validated in an expanded cohort by real-time PCR. The regulatory network was predicted by bioinformatic software and competitive endogenous RNA analysis, and was characterized in Caco-2 and HT-29 cell culture using methods of cell transfection, real-time PCR, Western blotting analysis, flow cytometry, and cell migration and invasion assays. Finally, these findings were confirmed in vivo using a CD animal model.

RESULTS

The 3' end of lncRNACNN3-206 and the 3’ UTR of Caspase10 contain high-affinity miR212 binding sites. lncRNACNN3-206 expression was found to be significantly increased in intestinal lesions of CD patients. Activation of the lncRNACNN3-206-miR-212-Caspase10 regulatory network led to increased apoptosis, migration and invasion in intestinal epithelial cells. Knockdown of lncRNACNN3-206 expression alleviated intestinal mucosal inflammation and tissue damage in the CD mouse model.

CONCLUSION

lncRNACNN3-206 may play a key role in CD pathogenesis. lncRNACNN3-206 could be a therapeutic target for CD treatment.

Mucus-penetrating budesonide nanosuspension enema for local treatment of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic inflammatory gastrointestinal disorder that affects more than 1 million individuals in the USA. Local therapy with enema formulations, such as micronized budesonide (Entocort®), is a common strategy for treating patients with distally active IBD. However, we hypothesize that micronized particulates are too large to effectively penetrate colorectal mucus, limiting the extent of drug delivery to affected tissues prior to clearance. Here, we describe the development of a budesonide nanosuspension (NS) with the appropriate surface coating and size to enhance penetration of colorectal mucus and ulcerated colorectal tissues. We demonstrate that model fluorescent polystyrene (PS) particles ∼200 nm in size with a muco-inert Pluronic F127 coating provide enhanced mucosal distribution and tissue penetration in mice with trinitrobenzenesulfonic acid (TNBS)-induced IBD compared to model 2 μm PS particles coated with polyvinylpyrollidone (PVP), the stabilizer used in the clinical micronized budesonide formulation. We then used a wet-milling process to develop a budesonide NS formulation with a muco-inert Pluronic F127 coating (particle size ∼230 nm), as well as a budesonide microsuspension (MS) stabilized with PVP (particle size ∼2 μm). Using an acute TNBS mouse model of IBD, we show that daily budesonide NS enema treatment resulted in a significant reduction in the macroscopic (decreased colon weight) and microscopic (histology score) symptoms of IBD compared to untreated controls or mice treated daily with the budesonide MS enema. Further, we show that the budesonide NS enema treated mice had a significantly reduced number of inflammatory macrophages and IL-β producing CD11b + cells in colon tissue compared to untreated controls or mice treated with the budesonide MS enema. We conclude that the nano-size and muco-inert coating allowed for enhanced local delivery of budesonide, and thus, a more significant impact on local colorectal tissue inflammation.

Insight into the pharmacokinetic behavior of tanshinone IIA in the treatment of Crohn's disease: comparative data for tanshinone IIA and its two glucuronidated metabolites in normal and recurrent colitis models after oral administration

1. Previous reports implied that tanshinone IIA (TSA) may offer potential benefits for Crohn's disease (CD). However, the detailed pharmacokinetic behavior of TSA in the treatment of colitis remain unclear. Herein, a recurrent trinitrobenzene sulfonic acid (TNBS)-colitis mouse model was used to investigate whether TSA possesses favorable pharmacokinetic and colonic distribution profiles to serve as a candidate drug. 2. Although the systemic TSA exposures were low (AUC_0-t approximately 330 ng*h/ml) in both the normal and colitis models after oral administration TSA 20 mg/kg, high levels of TSA were found in the gastrointestinal tract (GI). Such a GI exposure of TSA in colitis mice is adequate to exert anti-inflammatory effects as observed in various in vitro studies. 3. Interestingly, colonic TSA exposure in the colitis mouse model was much lower than that in the normal mice, which may be explained by a significant upregulation of colonic UDP-glucuronosyltransferase (Ugt)1a9 expression and a higher plasma concentration of TSA glucuronides in the model mice at 0.5, 1 and 2 h after TSA administration. 4. Together, these results reveal high accumulation at the site of inflammation and minimal systemic concentration of TSA, which are favorable pharmacokinetic behaviors to meet the requirements for CD treatment.

Lactobacillus plantarum NCIMB8826 ameliorates inflammation of colon and skin in human APOC1 transgenic mice

Genetic predisposition and environmental factors, including the gut microbiota, have been suggested as major factors in the development and progression of atopic dermatitis. Hyperlipidemic human APOC1+/+ transgenic mice display many features of human atopic dermatitis, such as scaling, lichenification, excoriations, and pruritus, along with a disturbed skin barrier function. Cytokine analysis of serum shows an increase of various pro-inflammatory cytokines, including interleukin (IL)-12p40, IL-6, and IL-1α, but lower levels of interferon-γ. These mice also display aspects of colitis evident from macroscopic and histological abnormalities. Genome-wide transcriptome analysis of the intestine shows up-regulation of several genes associated with mast cells and eosinophils and this observation was confirmed by demonstrating increased numbers of IgE+ and FcRε+ mast cells in the colon and in the skin. Oral treatment with Lactobacillus plantarum NCIMB8826 resulted in decreased numbers of mast cells in the colon. Moreover, this L. plantarum strain ameliorated skin pathology, evident from improved skin barrier integrity, absence of skin thickening, and less excoriations. These results suggest that modulation of intestinal immune homeostasis contributes to the suppression of atopic dermatitis.

Animal models to study acute and chronic intestinal inflammation in mammals

Acute and chronic inflammatory diseases of the intestine impart a significant and negative impact on the health and well-being of human and non-human mammalian animals. Understanding the underlying mechanisms of inflammatory disease is mandatory to develop effective treatment and prevention strategies. As inflammatory disease etiologies are multifactorial, the use of appropriate animal models and associated metrics of disease are essential. In this regard, animal models used alone or in combination to study acute and chronic inflammatory disease of the mammalian intestine paired with commonly used inflammation-inducing agents are reviewed. This includes both chemical and biological incitants of inflammation, and both non-mammalian (i.e. nematodes, insects, and fish) and mammalian (i.e. rodents, rabbits, pigs, ruminants, dogs, and non-human primates) models of intestinal inflammation including germ-free, gnotobiotic, as well as surgical, and genetically modified animals. Importantly, chemical and biological incitants induce inflammation via a multitude of mechanisms, and intestinal inflammation and injury can vary greatly according to the incitant and animal model used, allowing studies to ascertain both long-term and short-term effects of inflammation. Thus, researchers and clinicians should be aware of the relative strengths and limitations of the various animal models used to study acute and chronic inflammatory diseases of the mammalian intestine, and the scope and relevance of outcomes achievable based on this knowledge. The ability to induce inflammation to mimic common human diseases is an important factor of a successful animal model, however other mechanisms of disease such as the amount of infective agent to induce disease, invasion mechanisms, and the effect various physiologic changes can have on inducing damage are also important features. In many cases, the use of multiple animal models in combination with both chemical and biological incitants is necessary to answer the specific question being addressed regarding intestinal disease. Some incitants can induce acute responses in certain animal models while others can be used to induce chronic responses; this review aims to illustrate the strengths and weaknesses in each animal model and to guide the choice of an appropriate acute or chronic incitant to facilitate intestinal disease.

Quality of methods reporting in animal models of colitis

BACKGROUND

Current understanding of the onset of inflammatory bowel diseases relies heavily on data derived from animal models of colitis. However, the omission of information concerning the method used makes the interpretation of studies difficult or impossible. We assessed the current quality of methods reporting in 4 animal models of colitis that are used to inform clinical research into inflammatory bowel disease: dextran sulfate sodium, interleukin-10, CD45RB T cell transfer, and 2,4,6-trinitrobenzene sulfonic acid (TNBS).

METHODS

We performed a systematic review based on PRISMA guidelines, using a PubMed search (2000-2014) to obtain publications that used a microarray to describe gene expression in colitic tissue. Methods reporting quality was scored against a checklist of essential and desirable criteria.

RESULTS

Fifty-eight articles were identified and included in this review (29 dextran sulfate sodium, 15 interleukin-10, 5 T cell transfer, and 16 TNBS; some articles use more than 1 colitis model). A mean of 81.7% (SD = ±7.038) of criteria were reported across all models. Only 1 of the 58 articles reported all essential criteria on our checklist. Animal age, gender, housing conditions, and mortality/morbidity were all poorly reported.

CONCLUSIONS

Failure to include all essential criteria is a cause for concern; this failure can have large impact on the quality and replicability of published colitis experiments. We recommend adoption of our checklist as a requirement for publication to improve the quality, comparability, and standardization of colitis studies and will make interpretation and translation of data to human disease more reliable.

The Probiotic Mixture VSL#3 Has Differential Effects on Intestinal Immune Parameters in Healthy Female BALB/c and C57BL/6 Mice

BACKGROUND

Probiotic bacteria may render mice resistant to the development of various inflammatory and infectious diseases.

OBJECTIVE

This study aimed to identify mechanisms by which probiotic bacteria may influence intestinal immune homeostasis in noninflammatory conditions.

METHODS

The effect of VSL#3, a mixture of 8 probiotic bacteria, on intestinal gene expression was studied in healthy female BALB/c and C57BL/6 mice after prolonged oral treatment (28 d, triweekly) with 3 × 10(8) colony-forming units of VSL#3. In a separate experiment in BALB/c mice, the effects of prolonged administration of VSL#3 and of phosphate-buffered saline (PBS), followed by 1 single dose of VSL#3, on innate and adaptive immune cells were evaluated.

RESULTS

Microarray analysis of the intestines of mice treated with PBS confirmed well-established differences in the expression of immune-related genes between C57BL/6 and BALB/c mice. Prolonged administration of VSL#3 was associated with downregulation of Il13 [fold change (FC) = 0.46] and Eosinophil peroxidase (Epx) (FC = 0.44) and upregulation of Il12rb1 (FC = 2.1), C-C chemokine receptor type 5 (Ccr5) (FC = 2.6), chemokine (C-X-C motif) receptor 3 (Cxcr3) (FC = 1.6), and C-X-C motif chemokine 10 (Cxcl10) (FC = 2.8) in BALB/c mice but not in C57BL/6 mice. In BALB/c mice, it was shown that 28 d of treatment with VSL#3 affected the Peyer's patches (PPs) and mesenteric lymph nodes (MLNs), which was evident from an increase in B cells (26% and 8%, respectively), a decrease in T cells (21% and 8%, respectively), and an increase in cluster of differentiation (CD) 11c(+) cells (57% in PPs) compared with PBS-treated mice. This treatment was also associated with increased frequencies of T helper 17 (13%) and regulatory T cells (11%) in the MLNs. Treatment with PBS followed by 1 single dose of VSL#3, 18 h before killing, was associated with a 2-fold increase in CD103(+)CD11c(+) dendritic cells in MLNs and PPs.

CONCLUSION

VSL#3 treatment mediates mouse strain-specific alterations in immunologic phenotype in conditions of homeostasis, suggesting that the effects of probiotic bacteria depend on the genetic background of the host.

The probiotic mixture VSL#3 mediates both pro- and anti-inflammatory responses in bone marrow-derived dendritic cells from C57BL/6 and BALB/c mice

Probiotic bacteria express a wide range of molecular structures that bind to receptors on innate immune cells and mediate health-promoting effects in the host. We have recently demonstrated in a colitis model that favourable effects of the probiotic mixture VSL#3 may in part be due to the suppression of intestinal chemokine expression. To obtain more insights into the underlying mechanisms, in the present study, we analysed the modulation of bone marrow-derived dendritic cells (BM-DC) from BALB/c (T helper (Th)2 biased) v. C57BL/6 (Th1 biased) mice. Our findings showed that VSL#3 differed from pure Toll-like receptor (TLR) ligands by inducing the production of various cytokines, including IL-12 p70 subunit (IL-12p70), IL-23 and IL-10. Dedicated TLR arrays were employed to profile mRNA from BM-DC cultured with lipopolysaccharide (LPS), VSL#3, or a combination of both. This approach led to the identification of (1) a cluster of genes that were up- or down-regulated, irrespective of the stimulus, (2) a cluster of genes that were synergistically up-regulated by LPS and VSL#3 in BM-DC from C57BL/6 mice, but not in those from BALB/c mice, and (3) a cluster of LPS-induced genes that were suppressed by VSL#3, in particular chemokine genes. These data show that this probiotic mixture has both pro- and anti-inflammatory effects on BM-DC and suggest that their immune-modulating properties in vivo may depend on the genetic background of the host.

Animal models of inflammatory bowel disease: a review

Inflammatory bowel disease (IBD) represents a group of idiopathic chronic inflammatory intestinal conditions associated with various areas of the GI tract, including two types of inflammatory conditions, i.e., ulcerative colitis (UC) and Crohn's disease (CD). Both UC and CD are chronic inflammatory disorders of the intestine; in UC, inflammation starts in the rectum and generally extends proximally in a continuous manner through the entire colon. Bloody diarrhea, presence of blood and mucus mixed with stool, accompanied by lower abdominal cramping, are the characteristic symptoms of the disease. While in CD, inflammatory condition may affect any part of the GI tract from mouth to anus. It mainly causes abdominal pain, diarrhea, vomiting and weight loss. Although the basic etiology of IBD is unknown, there are several factors that may contribute to the pathogenesis of this disease, such as dysregulation of immune system or commensal bacteria, oxidative stress and inflammatory mediators. In order to understand these different etiological factors, a number of experimental models are available in the scientific research, including chemical-induced, spontaneous, genetically engineered and transgenic models. These models represent a major source of information about biological systems and are clinically relevant to the human IBD. Since there is less collective data available in one single article discussing about all these models, in this review an effort is made to study the outline of pathophysiology and various types of animal models used in the research study of IBD and other disease-related complications.