To improve treatment compliance and reach sustained and controlled drug release in the colon, we developed a hollow mesoporous silica nano-suppository that responded to both pH and redox stimuli. Firstly, we prepared hollow mesoporous silica nanoparticles containing disulfide bonds (HMSN-SS) and loaded them with 5-ASA. Secondly, we modified the surface of HMSN-SS with polydopamine (PDA) and chitosan (CS) and molded the suppository, which we named 5-ASA@HMSN-SS-PDA-CS (5-ASA@HSPC). By administering 5-ASA@HSPC rectally, it acted directly on the affected area. CS helped the nanoparticles adhere to the colon's surface, while PDA dissociates from HMSN-SS due to protonation in the acidic environment of the ulcerative colon. The disulfide bonds were destroyed by the reducing environment of the colon, leading to a stable and slow release of encapsulated 5-ASA from the pores of HMSN. Finally, in vitro release experiments and in vivo pharmacokinetic and pharmacodynamic experiments had demonstrated that 5-ASA@HSPC exhibited a slow and steady action at the colonic site, with an excellent safety profile. This novel approach showed great potential in the treatment of ulcerative colitis.

In a recent issue of the Lancet, the prevalence of Inflammatory Bowel Disease (IBD) was estimated at 7 million worldwide. Overall, the burden of IBD is rising globally, with direct and indirect healthcare costs ranging between $14.6 and $31.6 billion in the U.S. alone in 2014. There is currently no cure for IBD, and up to 40% of patients do not respond to medical therapy. Although the exact determinants of the disease pathophysiology remain unknown, the prevailing hypothesis involves complex interplay among host genetics, the intestinal microenvironment (primarily bacteria and dietary constituents), and the mucosal immune system. Importantly, multiple chronic diseases leading to high morbidity and mortality in modern western societies, including type II diabetes, IBD and colorectal cancer, have epidemiologically been linked to the consumption of high-calorie, low-fiber, high monosaccharide, and high-fat diets (HFD). More specifically, data from our laboratory and others have shown that repeated consumption of HFD triggers dysbiotic changes of the gut microbiome concomitant with a state of chronic intestinal inflammation and increased intestinal permeability. However, progress in our understanding of the effect of dietary interventions on IBD pathogenesis has been hampered by a lack of relevant animal models. Additionally, current in vitro cell culture systems are unable to emulate the in vivo interplay between the gut microbiome and the intestinal epithelium in a realistic and translatable way. There remains, therefore, a critical need to develop translatable in vitro and in vivo models that faithfully recapitulate human gut-specific physiological functions to facilitate detailed mechanistic studies on the impact of dietary interventions on gut homeostasis. While the study of murine models has been pivotal in advancing genetic and cellular discoveries, these animal systems often lack key clinical signs and temporal pathological changes representative of IBD. Specifically, some limitations of the mouse model are associated with the use of genetic knockouts to induce immune deficiency and disease. This is vastly different from the natural course of IBD developing in immunologically competent hosts, as is the case in humans and dogs. Noteworthily, abundant literature suggests that canine and human IBD share common clinical and molecular features, such that preclinical studies in dogs with naturally occurring IBD present an opportunity to further our understanding on disease pathogenesis and streamline the development of new therapeutic strategies. Using a stepwise approach, in vitro mechanistic studies investigating the contribution of dietary interventions to chronic intestinal inflammation and "gut leakiness" could be performed in intestinal organoids and organoid derived monolayers. The biologic potential of organoids stems from the method's ability to harness hard-wired cellular programming such that the complexity of the disease background can be reflected more accurately. Likewise, the effect of therapeutic drug candidates could be evaluated in organoids prior to longitudinal studies in dog and human patients with IBD. In this review, we will discuss the value (and limitations) of intestinal organoids derived from a spontaneous animal disease model of IBD (i.e., the dog), and how it can heighten understanding of the interplay between dietary interventions, the gut microbiota and intestinal inflammation. We will also review how intestinal organoids could be used to streamline the preclinical development of therapeutic drug candidates for IBD patients and their best four-legged friends.

Endoscopy is currently the gold standard for the diagnosis of inflammatory bowel disease (IBD). The presence of macroscopic lesions along with the microscopic detection of inflammatory infiltration in the terminal ileum often leads the gastroenterologist to the diagnosis of Crohn's disease (CD). However, some of these cases could be, in fact, an infection caused by Yersinia spp., accompanied or not with CD, which could be easily diagnosed with the identification of serum antibodies against Yersinia outer protein antigens (YOP antigens). Since Yersiniosis is considered to be an uncommon situation, food and water are not usually checked for the possibility of contamination by Yersinia. Therefore, it is reasonable to assume that the true prevalence of Yersinia infection in patients with terminal ileitis is probably underestimated. In this article, we review the most important data regarding the various aspects of Yersinia infection with special focus on its pathophysiology and diagnosis. We recommend testing for serum antibodies against YOP antigens in all patients with an endoscopic and histological image of terminal ileitis in order to identify Yersiniosis in conjunction or not with terminal ileum CD.

Crohn's disease (CD) is a highly heritable disease that is particularly common in the Ashkenazi Jewish population. We studied 2 large Ashkenazi Jewish families with a high prevalence of CD in an attempt to identify novel genetic risk variants.

Ashkenazi Jewish patients with CD and a positive family history were recruited from the University College London Hospital. We used genome-wide, single-nucleotide polymorphism data to assess the burden of common CD-associated risk variants and for linkage analysis. Exome sequencing was performed and rare variants that were predicted to be deleterious and were observed at a high frequency in cases were prioritized. We undertook within-family association analysis after imputation and assessed candidate variants for evidence of association with CD in an independent cohort of Ashkenazi Jewish individuals. We examined the effects of a variant in DUOX2 on hydrogen peroxide production in HEK293 cells.

We identified 2 families (1 with >800 members and 1 with >200 members) containing 54 and 26 cases of CD or colitis, respectively. Both families had a significant enrichment of previously described common CD-associated risk variants. No genome-wide significant linkage was observed. Exome sequencing identified candidate variants, including a missense mutation in DUOX2 that impaired its function and a frameshift mutation in CSF2RB that was associated with CD in an independent cohort of Ashkenazi Jewish individuals.

In a study of 2 large Ashkenazi Jewish with multiple cases of CD, we found the genetic basis of the disease to be complex, with a role for common and rare genetic variants. We identified a frameshift mutation in CSF2RB that was replicated in an independent cohort. These findings show the value of family studies and the importance of the innate immune system in the pathogenesis of CD.

Utilization of environmental stimuli for growth is the main factor contributing to the evolution of prokaryotes and eukaryotes, independently and mutualistically. Epigenetics describes an organism's ability to vary expression of certain genes based on their environmental stimuli. The diverse degree of dose-dependent responses based on their variances in expressed genetic profiles makes it difficult to ascertain whether hormesis or oncogenesis has or is occurring. In the medical field this is shown where survival curves used in determining radiotherapeutic doses have substantial uncertainties, some as large as 50% (Barendsen, 1990). Many in-vitro radiobiological studies have been limited by not taking into consideration the innate presence of microbes in biological systems, which have either grown symbiotically or pathogenically. Present in-vitro studies neglect to take into consideration the varied responses that commensal and opportunistic pathogens will have when exposed to the same stimuli and how such responses could act as stimuli for their macro/microenvironment. As a result many theories such as radiation carcinogenesis explain microscopic events but fail to describe macroscopic events (Cohen, 1995). As such, this review shows how microorganisms have the ability to perturb risks of cancer and enhance hormesis after irradiation. It will also look at bacterial significance in the microenvironment of the tumor before and during treatment. In addition, bacterial systemic communication after irradiation and the host's immune responses to infection could explain many of the phenomena associated with bystander effects. Therefore, the present literature review considers the paradigms of hormesis and oncogenesis in order to find a rationale that ties them all together. This relationship was thus characterized to be the microbiome.

One major challenge to studying human microbiome and its associated diseases is the lack of effective tools to achieve targeted modulation of individual species and study its ecological function within multispecies communities. Here, we show that C16G2, a specifically targeted antimicrobial peptide, was able to selectively kill cariogenic pathogen Streptococcus mutans with high efficacy within a human saliva-derived in vitro oral multispecies community. Importantly, a significant shift in the overall microbial structure of the C16G2-treated community was revealed after a 24-h recovery period: several bacterial species with metabolic dependency or physical interactions with S. mutans suffered drastic reduction in their abundance, whereas S. mutans' natural competitors, including health-associated Streptococci, became dominant. This study demonstrates the use of targeted antimicrobials to modulate the microbiome structure allowing insights into the key community role of specific bacterial species and also indicates the therapeutic potential of C16G2 to achieve a healthy oral microbiome.

A computational and in silico system level framework was developed to identify and prioritize the antibacterial drug targets in Clostridium botulinum (Clb), the causative agent of flaccid paralysis in humans that can be fatal in 5 to 10% of cases. This disease is difficult to control due to the emergence of drug-resistant pathogenic strains and the only available treatment antitoxin which can target the neurotoxin at the extracellular level and cannot reverse the paralysis. This study framework is based on comprehensive systems-scale analysis of genomic sequence homology and phylogenetic relationships among Clostridium, other infectious bacteria, host and human gut flora. First, the entire 2628-annotated genes of this bacterial genome were categorized into essential, non-essential and virulence genes. The results obtained showed that 39% of essential proteins that functionally interact with virulence proteins were identified, which could be a key to new interventions that may kill the bacteria and minimize the host damage caused by the virulence factors. Second, a comprehensive comparative COGs and blast sequence analysis of these proteins and host proteins to minimize the risks of side effects was carried out. This revealed that 47% of a set of C. botulinum proteins were evolutionary related with Homo sapiens proteins to sort out the non-human homologs. Third, orthology analysis with other infectious bacteria to assess broad-spectrum effects was executed and COGs were mostly found in Clostridia, Bacilli (Firmicutes), and in alpha and beta Proteobacteria. Fourth, a comparative phylogenetic analysis was performed with human microbiota to filter out drug targets that may also affect human gut flora. This reduced the list of candidate proteins down to 131. Finally, the role of these putative drug targets in clostridial biological pathways was studied while subcellular localization of these candidate proteins in bacterial cellular system exhibited that 68% of the proteins were located in the cytoplasm, out of which 6% was virulent. Finally, this framework may serve as a general computational strategy for future drug target identification in infectious diseases.

T cell proliferation and T helper (TH ) cells that make IL-17 (TH 17 cells) and IFN-γ (TH 1 cells) have been shown to be inhibited by 1,25(OH)2 D3 . Previous work has shown that immune-mediated diseases, where TH 1 and TH 17 cells are pathogenic, are ameliorated with 1,25(OH)2 D3 treatment. Paradoxically, infectious diseases that require TH 1 and TH 17 responses for host resistance are unaffected by 1,25(OH)2 D3 treatment. Resting T cells are not responsive to vitamin D because they do not express the vitamin D receptor (VDR) until late after activation. T cells activated following an infection help clear the infection, and since the antigen is eliminated, vitamin D is not needed to dampen the immune response. Conversely, in immune-mediated disease, there is chronic T cell activation, and in this scenario, vitamin D and 1,25(OH)2 D3 are critical for inhibiting T cell proliferation and cytokine production. Vitamin D is a late regulator of T cell function and acts to turn off T cells. This paper will review these data.

Although a substantial number of T cells may escape depletion following in vivo mAb treatment in patients undergoing immunosuppression, their specific tissue location and phenotypic characteristics in different peripheral lymphoid tissues have not been analyzed in detail. Here we investigated the survival of CD4(+) T cells immediately following anti-Thy-1 mAb treatment in mice. We found a preferential survival of CD4(+) T cells expressing Thy-1 antigen in the Peyer's patches (PP) and also in mesenteric lymph nodes (MLN), where the relative majority of the surviving CD4(+) T cells displayed CD44(high)/CD62L(-) phenotype corresponding to effector memory T-cell features. These CD4(+) T cells also expressed CXCR5 and PD-1 (programmed cell death-1) markers characteristic for follicular Th cells (TFH). We also demonstrate that the immediate survival of these cells does not involve proliferation and is independent of IL-7. Induction of germinal center formation in spleen enhanced while the dissolution of follicular architecture by lymphotoxin-β receptor antagonist treatment slightly reduced TFH survival. Our results thus raise the possibility that the follicles within PP and MLN may create natural support niches for the preferential survival of TFH cells of the memory phenotype, thus allowing their escape during T-cell depletion.

Nanotechnology involves the creation and manipulation of materials at nanoscale levels (1-100 nm) to create products that exhibit novel properties. While this motivation has driven nanoscience and technology in physics and engineering, it is not the main reason that nanoparticles are useful for systemic applications in the human body. The application of nanotechnology to medicine, known as nanomedicine, concerns the use of precisely engineered materials at this length scale to develop novel therapeutic and diagnostic modalities. A number of nanotherapeutic formulations are already approved for medical use and more are in the approval pipeline currently. This chapter is intended to provide an overview of the toxicity of these therapeutic nanoparticles and to summarize the current state of the field. We begin with background on the sources of exposure to nanoparticles, followed by reviewing different forms of nanosized therapeutic tools as quantum dots, nanoshells, nanocapsules, echogenic bubble, and "nanoshuttles." Moreover, cytotoxic effects of nanoparticles on cell membrane, mitochondrial function, prooxidant/antioxidant status, enzyme leakage, DNA, and other biochemical endpoints were elucidated. We highlight the need for caution during the use and disposal of such manufactured nanomaterials to prevent unintended environmental impacts. Moreover, different strategies which could be used to minimize or eliminate nanotoxicity were also discussed in detail. Understanding of how to tune size and surface properties to provide safety will permit the creation of new, more effective nanomedicines for systemic use.

The gastrointestinal (GI) tract is home to trillions of microbes. Within the same GI tract, substantial differences in the bacterial species that inhabit the oral cavity and intestinal tract have been noted. While the influence of host environments and nutritional availability in shaping different microbial communities is widely accepted, we hypothesize that the existing microbial flora also plays a role in selecting the bacterial species that are being integrated into the community. In this study, we used cultivable microbial communities isolated from different parts of the GI tract of mice (oral cavity and intestines) as a model system to examine this hypothesis. Microbes from these two areas were harvested and cultured using the same nutritional conditions, which led to two distinct microbial communities, each with about 20 different species as revealed by PCR-based denaturing gradient gel electrophoresis analysis. In vitro community competition assays showed that the two microbial floras exhibited antagonistic interactions toward each other. More interestingly, all the original isolates tested and their closely related species displayed striking community preferences: They persisted when introduced into the bacterial community of the same origin, while their viable count declined more than three orders of magnitude after 4 days of coincubation with the microbial flora of foreign origin. These results suggest that an existing microbial community might impose a selective pressure on incoming foreign bacterial species independent of host selection. The observed inter-flora interactions could contribute to the protective effect of established microbial communities against the integration of foreign bacteria to maintain the stability of the existing communities.

ATP binding cassette (ABC) transporters are increasingly recognized for their ability to modulate the absorption, distribution, metabolism, secretion and toxicity of xenobiotics. In addition to their essential function in drug resistance, there is also emerging evidence documenting the important role ABC transporters play in tissue defense. In this respect, the gastrointestinal tract represents a critical vanguard of defense against oral exposure of drugs while at the same time functions as a physical barrier between the lumenal contents (including bacteria) and the intestinal epithelium. Given emerging evidence suggesting that multidrug resistance protein (MDR) plays an important role in host-bacterial interactions in the gastrointestinal tract, this review will discuss the interplay between MDR of the intestinal epithelial cell barrier and gut microbes in health and disease. In particular, we will explore host-microbe interactions involving three apically restricted ABC transporters of the intestinal epithelium; P-glycoprotein (P-gp), multidrug resistance-associated protein 2 (MRP2) and cystic fibrosis transmembrane regulator (CFTR).

To evaluate the role of genetic factors in the pathogenesis of Crohn's disease (CD) and ulcerative colitis (UC), we investigated the single nucleotide polymorphisms (SNPs) of NOD2/CARD15 (R702W, G908R and L1007finsC), and Toll-like receptor 4 (TLR4) genes (D299G and T399I) in a selected inflammatory bowel disease (IBD) population coming from Southern Italy.

Allele and genotype frequencies of NOD2/CARD15 (R702W, G908R and L1007finsC) and TLR4 (D299G and T399I) SNPs were examined in 133 CD patients, in 45 UC patients, and in 103 healthy controls. A genotype-phenotype correlation was performed.

NOD2/CARD15 R702W mutation was significantly more frequent in CD (9.8%) than in controls (2.4%, P = 0.001) and in UC (2.3%, P = 0.03). No significant difference was found between UC patients and control group (P > 0.05). In CD and UC patients, no significant association with G908R variant was found. L1007finsC SNP showed an association with CD (9.8%) compared with controls (2.9%, P = 0.002) and UC patients (2.3%, P = 0.01). Moreover, in CD patients, G908R and L1007finsC mutations were significantly associated with different phenotypes compared to CD wild-type patients. No association of IBD with the TLR4 SNPs was found in either cohort (allele frequencies: D299G-controls 3.9%, CD 3.7%, UC 3.4%, P > 0.05; T399I-controls 2.9%, CD 3.0%, UC 3.4%, P > 0.05).

These findings confirm that, in our IBD patients selected from Southern Italy, the NOD2/CARD15, but not TLR4 SNPs, are associated with increased risk of CD.

The purpose was to study the spatial distribution of cases of inflammatory bowel disease (IBD) and characterize municipalities with high incidences in a search for environmental risk factors.

Spatial clustering of patients diagnosed with IBD during 1990-1993 were studied in 4 counties in southeastern Norway, and an ecological analysis was conducted to study the relationship between risk of IBD in the municipalities and their characteristics such as population, health care, urban/rural change, and socioeconomic change.

One cluster consisting of 4 municipalities was identified for IBD in Østfold county (P = 0.011). The ecological analysis showed that the incidence rate of IBD was 33% (95% confidence interval [CI]: 2%-75%) higher in municipalities with the highest level of education compared to the lowest level of education and 35% (2%-78%) higher in urban than rural municipalities. The incidence rate was 11% (1%-20%) lower in municipalities with a high urban/rural change compared to municipalities with low urban/rural change. Individuals living in high-risk municipalities were 3 times (1.57-5.45) more likely to have a first-degree family member with IBD than individuals living in normal-risk municipalities.

The geographic distribution of cases with IBD is not uniformly distributed and is related to urbanization, level of education, and moving pattern. Geographic distribution may be explained by either changes in environment-host relationships or neurobiological mechanisms due to stress and economic frustration. These factors and genetic predisposition might also explain increased familial clustering. Spatial clustering was significant neither for Crohn's disease CD nor ulcerative colitis (UC) but showed a stronger tendency within the CD group.

CARD15 gene mutations may present different frequencies in populations and sometimes surgical interventions may become a necessary therapy for inflammatory bowel disease patients. Mutations of 1007fs, G908R, R702W and polymorphisms of P268S, IVS8+158 of the CARD15 gene and their relation with disease-related surgery were investigated in Turkish inflammatory bowel disease patients in this study.

1007fs, G908R, R702W mutations and P268S, IVS8+158 polymorphisms of CARD15 gene were analyzed in 130 inflammatory bowel disease patients (67 Crohn's disease, 63 ulcerative colitis) and 87 healthy controls. After obtaining DNA samples, genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. Results were evaluated by statistical analysis and accepted as significant if P < 0.05.

R702W gene mutation was significantly lower in the inflammatory bowel disease group (1.5%) than the controls (4.8%) (P < 0.05). The overall allele frequency of mutations in the inflammatory bowel disease group (2.7%) was lower than in controls (6.6%) (P < 0.05). Disease-related surgery history was present in 20 Crohn's and 25 ulcerative colitis patients; familial history was present in four Crohn's and five ulcerative colitis patients. Statistically, no relationship was detected between disease-related surgeries and the investigated genetic tests.

In Turkish patients, no important relationship was detected between the investigated allele frequencies of the CARD15 gene and inflammatory bowel disease nor between disease-related surgeries and inflammatory bowel disease.

Three CAspase Recruitment Domain (CARD15) mutations have shown to predispose to Crohn's disease in Caucasian populations. The aim of this study was to investigate the mutation frequency in patients with inflammatory bowel disease and in healthy controls in Denmark.

Genotyping of the three common CARD15 mutations was carried out on 388 patients with Crohn's disease, 565 patients with ulcerative colitis and 796 healthy controls using real-time PCR. Allele and genotype frequencies in the three groups were compared. A possible additive effect of smoking on CARD15 mutations was also examined.

Carrying at least one CARD15 mutation was significantly more common in patients with Crohn's disease compared with healthy controls (21% versus 10%; p <0.001). A gene-dosage effect was observed (ORadj.smoking 22.2; p <0.001 for carrying two CARD15 mutations versus ORadj.smoking 1.8; p=0.01 for carrying one CARD15 mutation). The 1007insC protein truncating mutation was the major contributing mutation. Ileal involvement was more common in Crohn's disease patients with CARD15 mutations as opposed to patients without CARD15 mutations (ORadj.smoking 3.6; p <0.001). Smoking was independently associated with Crohn's disease (OR 1.8; p <0.001), but no multiplicative effect of smoking on CARD15 genotypes was found.

In the Danish population, CARD15 mutations were found to be associated with Crohn's disease, hence supporting the hypothesis of a genetic component contributing to the disease. Further research for other genes possibly involved in Crohn's disease may result in the use of genetic testing for diagnosis or treatment of Crohn's disease in the future.

Inflammatory bowel diseases (IBDs), including Crohn disease (CD) and ulcerative colitis (UC), often affect children and adolescents. Their diagnosis is based on the integration of clinical, biological, endoscopic, histological and radiological data. The paediatric radiologist may help the clinician in many ways. In children presenting with symptoms compatible with IBD, gut exploration by US may identify those who will benefit from more invasive explorations including endoscopy. During the process of diagnosis, small bowel exploration has a crucial role in differentiating CD from UC and in classifying the disease into subphenotypes. Finally, new imaging methods are useful during patient follow-up for assessing disease activity and for the diagnosis of complications.

Zinc (Zn) and its binding protein metallothionein (MT) have been proposed to suppress the disease activity in ulcerative colitis. To determine the role of Zn and MT in the dextran sulfate sodium (DSS)-induced model of colitis in mice, a DSS dose-response study was conducted in male C57BL/6 wild-type (MT+/+) and MT-null (MT-/-) mice by supplementing 2%, 3%, and 4% DSS in the drinking water for 6 days. In the intervention study, colitis was induced with 2% DSS, Zn (24 mg/ml as ZnO) was gavaged (0.1 ml) daily, concurrent with DSS administration, and the disease activity index (DAI) was scored daily. Histology, MT levels, and myeloperoxidase (MPO) activity were determined. DAI was increased (P<0.05) by 16% and 21% with 3% and 4% concentrations of DSS, respectively, compared to 2%, evident after 5 days of DSS administration. MPO activity was increased in MT+/+ compared to MT-/- mice and those receiving DSS. Zn administration had a 50% (P<0.05) lower DAI compared to DSS alone. Zn partially prevented the distal colon of MT+/+ by 47% from DSS-induced damage compared to MT-/- mice. MT did not prevent DSS-induced colitis and Zn was partially effective in amelioration of DSS-induced colitis.

Crohn's disease (CD) is a chronic inflammatory disorder of the gastrointestinal tract with variations in localization and behaviour. Mutations in the NOD2/CARD15 gene on chromosome 16q have been implicated in the pathogenesis of the disease and three main sequence variants, all single nucleotide polymorphisms (SNPs), have been identified in North American and European populations.

As no data exist in the Croatian population, we consecutively collected a cohort of 136 CD patients and 91 healthy controls to determine the prevalence of NOD2/CARD15 mutations and their association with phenotypic expression of the disease. All patients and controls were genotyped for Arg702Trp (Hugot SNP8), Gly908Arg (Hugot SNP12), and Leu1007fsinsC (Hugot SNP13) and allele frequencies were compared between the Crohn's patients and controls. The correlation of NOD2/CARD15 genotypes with the phenotypic expression of Crohn's disease was further assessed by logistic regression analysis.

NOD2/CARD15 variants were found in 38/136 CD patients (27.9%) compared to 10/91 (10.9%) healthy controls (P = 0.0022). Allele frequencies in patients with CD were 13.97%, 4.4% and 11.76%, respectively, for SNP8, 12 and 13, compared to 5.49%, 1.12% and 4.40% in controls (P = 0.041, P = 0.162, P = 0.055). Six CD patients carried double mutations and, remarkably, we identified two homozygous mutants amongst the healthy control group. Surgery over the course of the disease and a younger age at onset of the disease were significantly more frequent in patients who were carriers of NOD2/CARD15 mutations.

This report on NOD2/CARD15 mutations in Croatian patients with CD demonstrates that this gene is also implicated in susceptibility to CD in the Croatian population. Phenotypic association showed a younger age at diagnosis and a higher need for surgery in patients carrying NOD2/CARD15 mutations. However, the prevalence is somewhat lower compared to other reports, likely due to a more prominent colonic inflammation.

Although the association between inflammatory bowel disease and gastrointestinal infections has been suggested, the mechanisms involved in the pathogenesis of Crohn's disease (CD) are still undetermined. We report the case of a man, who presented with mesenteric adenitis initially due to a Yersinia pseudotubercolosis infection, who was later diagnosed with Crohn's disease. This case is in keeping with recent evidence in the literature which suggests that CD is a disease linked to abnormal immune responses to enteric bacteria in genetically susceptible individuals.

Crohn's disease (CD) is a chronic inflammatory bowel disease typified by transmural inflammation affecting any part of the gastrointestinal tract. CD4(+)CD25(+) regulatory T cells (T(reg) cells) play important roles in intestinal homeostasis. Adoptive transfer of regulatory T cells into mice with chronic colitis prevented inflammation and reappearance of normal intestinal architecture. The Foxp3 gene encodes a protein that is a member of the forkhead/winged-helix family of transcriptional regulators and is involved in the regulation of T cell activation. Mutation of Foxp3 gene may lead to development of autoimmune disease and inflammatory bowel disease. We investigated 10 single-nucleotide polymorphisms (SNPs) of the Foxp3 gene in CD patients and assessed allele and genotype frequencies in 93 patients with Crohn's disease (61 female and 32 male), 82 patients with primary biliary cirrhosis (PBC) (all female), and 108 normal controls (51 female and 57 male). We found that 3 SNPs (-6054, -/ATT; -3279, A/C; -924, A/G) in the promoter region and 1 SNP (IVS9+459, T/C) in the intron 9 region existed in CD patients. No significant differences of allele and genotype frequencies of all four SNPs were observed between CD patients and controls (both female and male groups). However, there was a significance difference of the comparison between PBC patients and controls in the IVS9+459 SNP. These data indicate that SNPs of the Foxp3 gene are not significantly associated with CD but are associated with PBC.

The genetic susceptibility of people with certain NOD2/CARD15, NOD1/CARD4, and ICAM-1 gene variants to inflammatory bowel disease is still under investigation. The aim of this study was to investigate polymorphisms in the NOD2/CARD15 (R702W, G908R, and 3020insC), NOD1/CARD4 (E266K, D372N), and ICAM-1 (G241R, K469E) genes, which are known to be associated with inflammation, in Turkish patients with inflammatory bowel disease and healthy control groups.

The genotypes of 70 patients with endoscopically and histopathologically diagnosed Crohn's disease (38 men, 32 women; mean age, 38.8 +/- 1.3), 120 patients with ulcerative colitis (67 men, 53 women; mean age, 41.7 +/- 1.3) and 106 healthy control subjects (37 men, 69 women; mean age, 35.7 +/- 1.4), who stated that they had never had any prior bowel disease history, were compared. A polymerase chain reaction-restriction fragment length polymorphism analysis was performed for two variants of the ICAM-1 gene, the three main variants of the NOD2/CARD15 gene, and the E266K variant of the NOD1/CARD4 gene, and DNA sequencing was used for the D372N polymorphism of the NOD1/CARD4 gene.

In this study, the three previously described Crohn's disease-predisposing variants of the NOD2/CARD15 gene and the polymorphisms examined in the NOD1/CARD4 and ICAM-1 genes were not found to be associated with ulcerative colitis or Crohn's disease.

These findings suggest that the polymorphisms observed in the NOD2/CARD15, NOD1/CARD4, and ICAM-1 genes are not genetic susceptibility factors for Crohn's disease or ulcerative colitis in Turkey.

The pregnane X receptor (PXR) regulates an array of genes involved in the response to xenobiotics. Evidence from several studies suggests that xenobiotic metabolism may play a role in inflammatory bowel disease (IBD) and that low levels of PXR may be associated with disease expression. The aim of this study was to investigate the association of functional polymorphisms of the PXR encoding gene (NR1I2) with disease in IBD populations.

This was a case-control study examining 8 NR1I2 single nucleotide polymorphisms (SNPs) previously associated with altered activity of PXR-regulated genes in an Irish cohort including 422 patients with IBD and 350 ethnically matched controls.

We showed significant associations of NR1I2 with IBD, Crohn's disease (CD), and ulcerative colitis (UC) groups compared with a control population for SNPs -23585 (IBD: P = .000008; odds ratio [OR], 1.62; 95% confidence interval [CI], 1.31-2.00) and -24381 (IBD: P = .0002; OR, 1.50; 95% CI, 1.21-1.84). SNPs 7635 (P = .0008) and 8055 (P = .007) were found to be associated with IBD and CD but not UC. Risk of IBD is strongly correlated to genotype at these sites, especially for the -25385CC genotype (P = .00001; OR, 2.92; 95% CI, 1.87-4.66). We also show specific correlations of IBD phenotype with genotypes and haplotypes in the patient group.

These results show that genetic variation in the PXR encoding gene, which has been associated with altered activity of PXR, is strongly associated with susceptibility to IBD, CD, and UC.

Limited data exist on the specific association between gastroduodenal Crohn's disease (GDCD) and NOD2/CARD15 gene polymorphisms. The aim of this study was to assess the association between NOD2 polymorphisms and GDCD, and to assess the specific association between each of the 3 major allelic variants G908R, L1007P, and R702W and the clinical features of Crohn's disease. We retrospectively reviewed the records of 202 patients with confirmed Crohn's disease and complete data was performed. Seventy-one patients (35%) had at least 1 allelic variant: 55 had 1 variant, 4 were homozygous for L1007fs, 2 homozygous for R702W, and 10 were compound heterozygous. Eighteen patients with confirmed GDCD were identified; 10 (56%) had wild type, 4 (22%) had 1 variant, and 4 (22%) had 2 allelic variants (2 were L1007P homozygous and 2 compound heterozygous). Compared to patients without gastroduodenal involvement, those with GDCD were more likely to have 2 allelic variants (22% vs. 6%; odds ratio [OR] 2.7; 95% confidence interval [CI] 1.6-7.3) and to be homozygous for L1007P (11% vs. 1%; OR 5.2; 95% CI 2.5-9.4). G908R heterozygosity was associated with ileal involvement (OR 1.4; 95% CI 1.1-2.9) and smoking habits (OR 2.4; 95% CI 1.2-3.8), whereas L1007P homozygosity was associated with GDCD (OR 5.8; 95% CI 2.6-10.8). L1007P variation was associated with younger age at diagnosis as well. There was no specific association between R702W homo- or heterozygosity and any of the characteristics examined. In conclusion, GDCD is associated with double dose of the NOD2/CARD15 gene variants, particularly L1007P homozygosity. There is evidence of specific variant-phenotype associations. G908R heterozygosity is associated with ileal involvement and smoking, whereas L1007P homozygosity is strongly associated with GDCD and younger age at diagnosis.

Inflammatory bowel diseases (IBD) encompass Crohn's disease and ulcerative colitis, which are diseases characterized by chronic intestinal inflammation. IBD is believed to result from predisposing genetic and environmental factors (specific antigens and pathogen-associated molecular patterns) acting on the immunoregulatory system and causing inflammation of the gastrointestinal mucosa. IBD may be the result of an imbalance of effector (proinflammatory) and regulatory T-cell responses. Three scenarios indicative of the outcome of this balance exist in animal models: balanced effector and regulatory T cells resulting in a normal controlled inflammation; overactive effector T cells resulting in inflammation and disease; and an absence of regulatory T cells resulting in uncontrolled inflammation and severe, aggressive disease. The number of products under study for the treatment of IBD has increased from 3 products and 1 target in 1993 to more than 30 products and more than 10 targets in 2005. The number of products under development and continued investigations into the pathogenesis of IBD emphasize the need to expand clinical research efforts in IBD.

VIP exerts a spectrum of effects as a potent anti-inflammatory factor. In addition, VIP increases expression of MUC2, a major intestinal secretory mucin. We therefore investigated the effects of VIP on the promoter activity of the 5'-flanking region of the MUC2 gene. VIP activated MUC2 transcription in human colonic epithelial cells via cAMP signaling to ERK and p38. cAMP/Epac/Rap1/B-Raf signaling was not involved in MUC2 reporter activation. Furthermore, activation of MUC2 transcription was independent of many of the reported downstream effectors of G protein-coupled receptors, such as PKC, Ras, Raf, Src, calcium, and phosphoinositide 3-kinase. VIP induced cAMP response element-binding protein (CREB)/ATF1 phosphorylation, and this was prevented by treatment with inhibitors of either MEK or p38 and by PKA and MSK1 inhibitor H89. CREB/ATF1 and c-Jun were shown to bind to an oligonucleotide encompassing a distal, conserved CREB/AP1 site in the 5'-flanking region of the MUC2 gene, and this cis element was shown to mediate promoter reporter activation by VIP. This study has identified a new, functional cis element within the MUC2 promoter and also a new pathway regulating MUC2 expression, thus providing further insight into the molecular mechanism of VIP action in the colon. These findings are relevant to the normal biology of the colonic mucosa as well as to the development of VIP as a therapeutic agent for treatment of inflammatory bowel disease.