Clinical relevance of advances in genetics and pharmacogenetics of IBD

Colon-Targeted Oral Delivery of Hydroxyethyl Starch-Curcumin Microcapsules Loaded with Multiple Drugs Alleviates DSS-Induced Ulcerative Colitis in Mice

Combination therapy through colon-targeted oral delivery of multiple drugs presents a promising approach for effectively treating ulcerative colitis (UC). However, the codelivery of drugs with diverse physicochemical properties in a single formulation remains a formidable challenge. Here, microcapsules are designed based on hydroxyethyl starch-curcumin (HES─CUR) conjugates to enable the simultaneous delivery of hydrophobic dexamethasone acetate (DA) and hydrophilic cefazolin sodium (CS), yielding multiple drug-loaded microcapsules (CS/DA-loaded HES─CUR microcapsules, CDHC-MCs) tailored for colon-targeted therapy of UC. Thorough characterization confirms the successful synthesis and exceptional biocompatibility of CDHC-MCs. Biodistribution studies demonstrate that the microcapsules exhibit an impressive inflammatory targeting effect, accumulating preferentially in inflamed colons. In vivo experiments employing a dextran-sulfate-sodium-induced UC mouse model reveal that CDHC-MCs not only arrest UC progression but also facilitate the restoration of colon length and alleviate inflammation-related splenomegaly. These findings highlight the potential of colon-targeted delivery of multiple drugs within a single formulation as a promising strategy to enhance UC treatment, and the CDHC-MCs developed in this study hold great potential in developing novel oral formulations for advanced UC therapy.

IBD and Motherhood: A Journey through Conception, Pregnancy and Beyond

Inflammatory Bowel Disease (IBD) presents distinct challenges during pregnancy due to its influence on maternal health and pregnancy outcomes. This literature review aims to dissect the existing scientific evidence on pregnancy in women with IBD and provide evidence-based recommendations for clinical management. A comprehensive search was conducted across scientific databases, selecting clinical studies, systematic reviews, and other pertinent resources. Numerous studies have underscored an increased risk of complications during pregnancy for women with IBD, including preterm birth, low birth weight, neonates small for gestational age, and congenital malformations. Nevertheless, it's evident that proactive disease management before and throughout pregnancy can mitigate these risks. Continuation of IBD treatment during pregnancy and breastfeeding is deemed safe with agents like thiopurines, anti-TNF, vedolizumab, or ustekinumab. However, there's a call for caution when combining treatments due to the heightened risk of severe infections in the first year of life. For small molecules, their use is advised against in both scenarios. Effective disease management, minimizing disease activity, and interdisciplinary care are pivotal in attending to women with IBD. The emphasis is placed on the continual assessment of maternal and infant outcomes and an expressed need for further research to enhance the understanding of the ties between IBD and adverse pregnancy outcomes.

A Phenomenological Investigation of Trauma in 18 Adults Living With Inflammatory Bowel Disease

While trauma is recognized as being common in Inflammatory Bowel Disease (IBD) cohorts, limited research has explored how trauma impacts the lived experience of IBD. The aim of this study was to develop an understanding of how trauma impacts the experience of living with IBD and its subsequent management. An interpretative phenomenological analysis with thematic analysis was conducted. Eighteen adults with IBD participated in this qualitative research study. Key themes identified included: (1) Trauma was associated with the journey of IBD; (2) the impact of IBD and trauma, and (3) coping strategies. Pre-existing non-IBD trauma was prevalent, with several participants reporting links between traumatic events and their IBD diagnosis. Experiences of IBD trauma were described by participants across all stages of their illness journey. The study can assist healthcare professionals to better understand the experience of living with IBD and trauma and the factors that can contribute to traumatic responses.

Cyanidin-3-O-Glucoside Supplement Improves Sperm Quality and Spermatogenesis in a Mice Model of Ulcerative Colitis

Impaired fertility and low sperm quality are the global health problem with high attention. It has been noted that inflammation may impact fertility by affecting testicular spermatogenesis. Cyanidin-3-O-glucoside is a natural functional pigment with various health benefits. Nevertheless, studies on the mechanism by which C3G protects male reproduction in mice with ulcerative colitis remain scarce. The purpose of this study is to illustrate the potential mechanism of C3G for improving impaired fertility caused by colitis. A DSS-induced colitis model was applied to assess the effects of sperm quality with colitis and the health benefit role of C3G. Results indicated that C3G-treated mice exhibited higher body weight, longer colon length, less crypt damage and focal inflammation infiltration. Being consistent with that, low sperm count, low testis weight, high inflammation levels and abnormal thickness of seminiferous epithelium also observed in the DSS group were significantly recovered upon C3G treatment. These findings suggested that colitis has a close link to impaired fertility. Further analysis found that C3G could significantly suppress the inflammatory mediators in serum. Results conjointly indicated that C3G might improve the impaired fertility of mice with colitis by inhibiting inflammatory cytokines through the blood–testis barrier. C3G could be a promising daily supplement for ameliorating impaired fertility caused by colitis.

GBP4 is an immune-related biomarker for patients with ileocolonic Crohn’s disease by comprehensive analysis

Background: Extensive evidence has shown that immune cell infiltration is associated with the pathogenesis of Crohn’s disease (CD).

Methods: Differentially expressed genes (DEGs) from the GSE179285 dataset in the intestinal mucosa of CD patients and healthy individuals were then identified. The infiltration pattern of 22 immune cell types was assessed using the CIBERSORT algorithm. The DEGs and 22 immune cell types were combined to find the key gene network using weighted gene co-expression network analysis (WGCNA). A linear regression model for the relationship between the expression of the hub genes in CD patients and infiltration of immune cells was also developed. The utility and accuracy of the hub genes for CD diagnosis were assessed using receiver operating characteristic (ROC) analysis. The accuracy of the model was validated using the GSE20881 dataset.

Results: There were 1135 DEGs between the intestinal mucosal tissue of CD patients and healthy individuals. Of these DEGs, 711 genes were upregulated, whereas 424 of them were downregulated. There was also a significant difference in the infiltration of immune cells to the intestinal mucosal between the CD patients and healthy individuals. WGCNA revealed that the turquoise module genes were strongly correlated with the infiltration of M1 macrophages (cor =0.68, p = 10−16). Finally, the expression of GBP4, the identified hub gene, strongly correlated with the infiltration of M1 macrophages (adjusted r-squared =0.661, p < 2×10−16), and is a relatively good marker for CD diagnostic prediction (AUC =0.736). The relationship between GBP4 expression and infiltration of M1 macrophages (adjusted r-squared =0.435, p < 2×10−16) and diagnostic value of the gene (AUC =0.702) were verified using the GSE20881 validation dataset.

Conclusion: The expression of GBP4 is associated with the infiltration of M1 macrophages to the intestinal mucosa of CD patients.

Pharmacogenetics-based personalized treatment in patients with inflammatory bowel disease: A review

The development of treatment options has revolutionized the prognosis of inflammatory bowel disease (IBD). However, a particular group of patients still experience therapeutic failure or drug side effects. Although the high inter-patient variability in therapy is associated with clinical factors, including age, disease behavior, and disease duration, they attribute only a small proportion of inter-individual variability. Thus, pharmacogenetics evaluating associations between specific genetic variations and drug responses or side effects have focused on optimizing therapeutic efficacy and minimizing toxicity in IBD treatment. Thiopurine S-methyltransferase (TPMT) and nudix hydrolase 15 (NUDT15) are well-established predictive markers of thiopurine-induced myelosuppression. Low TPMT activity is related to increased 6-thioguanine nucleotide levels, subsequently leading to myelotoxicity. NUDT15 variants are strongly associated with thiopurine-induced early leukopenia in Asians, with a lower incidence of TPMT-deficient allele. The Korean Association for the Study of Intestinal Diseases guidelines recommend pretreatment determination of NUDT15 genotypes, especially in East Asians, and NUDT15 R139C measurement has been approved for clinical use since 2019. Several studies have attempted to identify powerful genetic markers for personalized medicine. In this article, we review the identified pharmacogenetics of currently available drugs, focusing on 5-aminosalicylic acid, glucocorticosteroids, thiopurines, and anti-tumor necrosis factor-alpha agents.

Progress in research of vedolizumab in treatment of inflammatory bowel disease

Inflammatory bowel disease is a kind of chronic inflammatory disease of the gastrointestinal tract with unclear etiology. At present, its main therapeutic drugs include aminosalicylates, glucocorticoids, immunosuppressive agents, and biological agents. With the deepening study of the disease and the progress of science and technology, there have been more and more studies on the targets for biological agents, including tumor necrosis factor-α, Janus kinase, interleukin, intestinal integrin, etc. As a humanized integrin antagonist, vedolizumab can selectively inhibit the interaction between integrin α4β7 and mucosal addressin cell adhesion molecule-1, and block the migration of lymphocytes to the intestinal tract to alleviate the intestinal inflammation, so as to achieve the therapeutic effect. This article reviews the mechanism, clinical efficacy, and application of vedolizumab in the treatment of inflammatory bowel disease.

Gastroenterology and Neurology

PURPOSE OF REVIEW

Just as gastrointestinal dysfunction may develop in the setting of neurologic disease, neurologic dysfunction may become evident in the setting of gastrointestinal disease. This article describes the range of neurologic features that have been described in three primary gastrointestinal diseases: celiac disease and gluten-related disorders, inflammatory bowel disease, and Whipple disease. Particular emphasis is placed on the controversial and evolving clinical picture of neurologic dysfunction in disorders of gluten sensitivity.

RECENT FINDINGS

Gluten-related disorders, including both the traditional autoimmune-based celiac disease and the more recently recognized nonautoimmune, nonallergic gluten sensitivity, have been the source of much attention in both medical and lay publications. The possible association between Crohn disease and neurologic disorders also is receiving attention. The recognition that, although Whipple disease is an exceedingly rare disorder, a surprising percentage of the population may be asymptomatic stool carriers of the causative organism makes it important to always be cognizant of the disorder.

SUMMARY

The range of neurologic dysfunction in gastrointestinal diseases is broad and spans the spectrum from peripheral to central processes. Peripheral neuropathy, myopathy, myelopathy, cerebrovascular events, epilepsy, encephalopathy, and cerebellar dysfunction have all been described. Neurologists should be aware of the possibility that an underlying gastrointestinal disease process may be present in and responsible for the neurologic dysfunction that has prompted referral of an individual for evaluation.

Maternal exposure to low levels of corticosterone during lactation protects adult rat progeny against TNBS-induced colitis: A study on GR-mediated anti-inflammatory effect and prokineticin system

The early phase of life represents a critical period for the development of an organism. Interestingly, early life experiences are able to influence the development of the gastrointestinal tract and the reactivity to colonic inflammatory stress. We recently demonstrated that adult male rats exposed to low doses of corticosterone during lactation (CORT-nursed rats) are protected against experimental colitis induced by the intracolonic infusion of 2,4,6-trinitrobenzenesulfonic acid (TNBS). Based on these interesting results, we wanted to better investigate which cellular actors could be involved in the protection of CORT-nursed rats from TNBS-induced experimental colitis. Therefore, in the present work, we focused our attention on different factors implicated in GR-mediated anti-inflammatory effect. To address this issue, colonic tissues, collected from control and CORT-nursed healthy animals and from control and CORT-nursed colitic rats, were processed and the following inflammatory factors were evaluated: the expression of (i) glucocorticoid receptors (GR), (ii) glucocorticoid-induced leucine zipper (GILZ), (iii) phospho-p65NF-κB, (iv) the pro-inflammatory cytokines IL-1β and TNF-α, (v) the prokineticins PK2 and PK2L and (vi) their receptors PKR1 and PKR2. We found that adult CORT-nursed rats, in comparison to controls, showed increased expression of colonic GR and reduced expression of pro-inflammatory molecules (IL-1β, TNF-α, PK2 and PK2L) in response to inflammatory colitis. The observed changes were associated with an increase in GILZ colonic expression and with a reduction in phospo-p65NF-κB colonic expression.

Genetic Markers Associated with Clinical Outcomes in Patients with Inflammatory Bowel Disease

Genetic factors play a significant role in determining inflammatory bowel disease (IBD) susceptibility. Epidemiologic data support genetic contribution to the pathogenesis of IBD, which include familial aggregation, twin studies, and racial and ethnic differences in disease prevalence. Recently, several new genes have been identified to be involved in the genetic susceptibility to IBD. The characterization of novel genes potentially will lead to the identification of therapeutic agents and clinical assessment of phenotype and prognosis in patients with IBD. The development of genetic markers associated with clinical outcomes in patients with IBD will be very important in the future. The progress of molecular biology tools (microarrays, proteomics, and epigenetics) have progressed the field of the genetic markers discovery. The advances in bioinformatics coupled with cross-disciplinary collaborations have greatly enhanced our ability to retrieve, characterize, and analyze large amounts of data generated by the technological advances. The techniques available for markers development are genomics (single nucleotide polymorphism genotyping, pharmacogenetics, and gene expression analyses) and proteomics. This could be a potential great benefit in predicting the course of disease in individual patients and in guiding appropriate medical therapy.

Species-specific engagement of human nucleotide oligomerization domain 2 (NOD)2 and Toll-like receptor (TLR) signalling upon intracellular bacterial infection: role of Crohn's associated NOD2 gene variants

Recognition of bacterial peptidoglycan-derived muramyl-dipeptide (MDP) by nucleotide oligomerization domain 2 (NOD2) induces crucial innate immune responses. Most bacteria carry the N-acetylated form of MDP (A-MDP) in their cell membranes, whereas N-glycolyl MDP (G-MDP) is typical for mycobacteria. Experimental murine studies have reported G-MDP to have a greater NOD2-stimulating capacity than A-MDP. As NOD2 polymorphisms are associated with Crohn's disease (CD), a link has been suggested between mycobacterial infections and CD. Thus, the aim was to investigate if NOD2 responses are dependent upon type of MDP and further to determine the role of NOD2 gene variants for the bacterial recognition in CD. The response pattern to A-MDP, G-MDP, Mycobacterium segmatis (expressing mainly G-MDP) and M. segmatisΔnamH (expressing A-MDP), Listeria monocytogenes (LM) (an A-MDP-containing bacteria) and M. avium paratuberculosis (MAP) (a G-MDP-containing bacteria associated with CD) was investigated in human peripheral blood mononuclear cells (PBMCs). A-MDP and M. segmatisΔnamH induced significantly higher tumour necrosis factor (TNF)-α protein levels in healthy wild-type NOD2 PBMCs compared with G-MDP and M. segmatis. NOD2 mutations resulted in a low tumour necrosis factor (TNF)-α protein secretion following stimulation with LM. Contrary to this, TNF-α levels were unchanged upon MAP stimulation regardless of NOD2 genotype and MAP solely activated NOD2- and Toll-like receptor (TLRs)-pathway with an enhanced production of interleukin (IL)-1β and IL-10. In conclusion, the results indicate that CD-associated NOD2 deficiencies might affect the response towards a broader array of commensal and pathogenic bacteria expressing A-MDP, whereas they attenuate the role of mycobacteria in the pathogenesis of CD.

Organic cation transporter Octn1-mediated uptake of food-derived antioxidant ergothioneine into infiltrating macrophages during intestinal inflammation in mice

OCTN1/SLC22A4 is expressed on apical membranes of small intestine, and is involved in gastrointestinal absorption of its substrates, including the food-derived antioxidant ergothioneine (ERGO). ERGO concentration in circulating blood of patients with inflammatory bowel disease (Crohn's disease) is lower than that in healthy volunteers; thus, circulating ERGO is a potential diagnostic marker, although the mechanisms underlying low ERGO concentration in patients are unknown. Here, we focused on intestinal macrophages, which infiltrate sites of inflammation, and examined possible first-pass uptake of ERGO by macrophages. ERGO concentration in blood was lower in mice with dextran sodium sulfate (DSS)-induced colitis than in controls. On the other hand, expression of octn1 gene product and ERGO concentration in intestinal tissues of DSS-treated mice were higher than in controls. Interestingly, lamina propria mononuclear cells (LPMCs) isolated from DSS-treated mice contained ERGO and showed [(3)H]ERGO uptake and Octn1 expression, whereas ERGO was undetectable in LPMCs of control mice. Functional expression of OCTN1 was also confirmed in LPS-stimulated human macrophage-like cell line, THP-1. In conclusion, OCTN1 is functionally expressed on activated intestinal macrophages, and ERGO uptake into these immune cells could contribute at least in part to the altered disposition of ERGO in intestinal inflammation.

Biological therapy for ulcerative colitis: An update

Of the diverse biological agents used for patients with ulcerative colitis, the anti-tumor necrosis factor-α agents infliximab and adalimumab have been used in large-scale clinical trials and are currently widely used in the treatment of inflammatory bowel disease patients. Recent studies have indicated that golimumab, oral tofacitinib and vedolizumab reportedly achieved good clinical response and remission rates in ulcerative colitis patients. Thus, we believe that the detailed investigation of various studies on clinical trials may provide important information for the selection of appropriate biological agents, and therefore, we have extensively reviewed such trials in the present study.

Role of genes, the environment and their interactions in the etiology of inflammatory bowel diseases

Few of the studied genes demonstrate association with inflammatory bowel disease (IBD). Three mutations in the nucleotide-binding oligomerization domain 2 gene have consistently shown to be independent risk factors for Crohn's disease, but none of the alleles exhibited high sensitivity or specificity for IBD. Linkage analysis implicated several loci on various chromosomes, and epistasis has been demonstrated. The etiopathogenesis of IBD remains unknown, and environmental contribution to their pathogenesis is evident from genetic studies that demonstrated incomplete monozygotic twins concordandance rate for both Crohn's and ulcerative colitis. Smoking has shown an opposite effect on disease phenotype, with an adverse effect on disease course for Crohn's disease, but a slight beneficial effect in ulcerative colitis. The contribution of infectious agents to susceptibility to IBD appears to be strong. However, the role of nutrition on the etiology and therapy of IBD is not clear. Inconsistencies in environmental risk factors could be due to gene-environment interactions, making it essential to study the role of genetics and environmental contribution to the etiopathology of IBD. Transgenic or knockout mice, such as interleukin-10(-/-), T-cell receptor alpha(-/-), Galphai(2) (-/-) and N-cadherin(-/-), develop colitis-like inflammation similar to humans. Therefore, animal models must be further studied to explore mechanistic interactions.

Role of miR-19a targeting TNF-α in mediating ulcerative colitis

OBJECTIVE

Ulcerative colitis (UC) is a widely studied inflammatory disease associated with differential expression of genes involved in immune function, wound healing, and tissue remodeling. MicroRNAs have been reported to play a role in various cancer types. However, the mechanism of how microRNAs regulate UC remains unclear.

METHODS

In the present study, we investigated the role of miR-19a and tumor necrosis factor (TNF)-α in human colon tissues with UC and dextran sodium sulfate (DSS)-induced experimental colitis.

RESULTS

We identified that the expression of miR-19a was significantly reduced and TNF-α was remarkably increased in human colon tissue with UC. Moreover, this observation of miR-19a and TNF-α was also occurred in DSS-treated mice colitis. Further, we observed that miR-19a directly regulated TNF-α expression because miR-19a can suppress the expression of wild-type TNF-α reporter, but not the mutant form. The expression of inflammatory factors TNF-α, IL-8, and GM-GSF were significantly elevated upon application of miR-19a inhibitor.

CONCLUSION

Taken together, this study determines the levels of miR-19a and TNF-α in both DSS-induced experimental murine colitis and human UC and further demonstrates that miR-19a might directly regulate TNF-α. The findings may provide a new insight in the clinical treatment of UC.

Associations between vitamin D receptor polymorphisms and susceptibility to ulcerative colitis and Crohn's disease: a meta-analysis

BACKGROUND

Several polymorphisms have been identified in the vitamin D receptor (VDR) gene, while their roles in the incidence of ulcerative colitis (UC) and Crohn's disease (CD) are conflicting. This meta-analysis was designed to clarify the impact of these polymorphisms on UC and CD risk.

METHODS

The PubMed, Embase, and Cochrane electronic databases were searched from February 1995 to August 2011 for studies on the four VDR polymorphisms: TaqI, BsmI, FokI, and ApaI. Data were extracted and pooled odd ratios (ORs) and 95% confidence intervals (95% CIs) were calculated.

RESULTS

Nine studies were included. In Asians, the ff genotype of FokI was associated with increased UC risk (OR = 1.65; 95% CI, 1.11- 2.45). The "a" allele carrier status of ApaI appeared to be a protective factor for CD (OR = 0.81; 95% CI, 0.67-0.97). The tt genotype increased the risk of CD in Europeans (OR = 1.23; 95% CI, 1.02-1.49). Moreover, the tt genotype of TaqI in males had a moderate elevated risk of UC (OR = 1.56; 95% CI, 1.02-2.39) and CD (OR = 1.84; 95% CI, 1.19-2.83).

CONCLUSIONS

The meta-analysis reveals a significant increase in CD risk for Europeans carrying TaqI tt genotype and a significant decrease in CD risk for all carriers of the Apal "a" allele. For Asians, the VDR FokI polymorphism appears to confer susceptibility to UC. For males, the TaqI tt genotype is associated with susceptibilities to both UC and CD. Our study explored the genetic risk prediction in UC and CD, and may provide valuable insights into IBD therapy.

Promoter polymorphism of the EED gene is associated with the susceptibility to ulcerative colitis

BACKGROUND

Embryonic ectoderm development (EED) protein is involved in multiple cellular protein complexes. EED mediates the repression of gene activity through histone deacetylation, and it may act as a specific regulator of integrin's function. This gene was identified as a candidate gene for the susceptibility to IBD by our previous cDNA microarray analysis.

AIM

The present study aimed to validate the expression level of the EED gene in patients with IBD by performing RT-PCR, and we investigated whether the polymorphisms in the EED gene are associated with the susceptibility to UC, and whether a functional EED promoter polymorphism is related to UC.

METHODS

Genotype analysis of the EED SNPs was performed by single-base extension analysis. The haplotype frequencies of the EED gene for multiple loci were estimated using the expectation maximization algorithm. The promoter region of the human EED gene, including the g.-1850G>C allele, was isolated by PCR. The amplified PCR products were inserted into the pGL3-basic vector and the luciferase activity was analyzed.

RESULTS

The expression level of the EED gene was significantly decreased in both the UC and CD patients and it was significantly higher in the liver and ileum than in the other tissues of the human digestive system. The genotype and allele frequencies of the g.-1850G>C polymorphism of the EED gene in the UC patients were significantly different from those of the healthy controls (p = 0.018 and 0.017, respectively). The luciferase activity assay showed that the promoter activity was decreased about twofold in the construct containing the g.-1850G allele compared to that of the construct containing the g.-1850C allele, which means that the allele G could produce less EED mRNA.

CONCLUSIONS

These results suggest that the g.-1850G>C polymorphism in the EED gene might be associated with the susceptibility to UC by the change of the EED expression level.

Risk factors for inflammatory bowel diseases according to the "hygiene hypothesis": a case-control, multi-centre, prospective study in Southern Italy

BACKGROUND

Ulcerative colitis (UC) and Crohn's disease (CD) are inflammatory bowel diseases (IBD) of unknown aetiology. The 'hygiene hypothesis' (HH) suggests that several hygiene-related factors may have contributed to the increased incidence of IBD. The aim of the study was to evaluate risk factors for IBD related to HH in a cohort of IBD patients from the south of Italy.

METHODS

We prospectively performed a one-year, questionnaire-based, case-control, multi-centre study focusing on the principal risk factors for IBD according to HH. We investigated the main surrogate markers of HH (helmintic infections and antibiotics in childhood; breastfeeding; family size/sibship;urban upbringing; personal and domestic hygiene in childhood) in UC and CD patients, in comparison with a control group of healthy subjects. In addition, the traditional risk factors for IBD were also recorded.

RESULTS

The study population included 527 cases of UC, 468 CD and 562 controls. None of the surrogate risk factors of HH was significantly associated with IBD. On the contrary, the traditional risk factors confirmed their statistical significance in this IBD population. Familial aggregation: OR 4.07 for UC; OR 4.83 for CD; smoking: OR 0.38 for UC; OR 1.40 for CD; appendectomy: OR 0.28 for UC; OR 1.61 for CD.

CONCLUSION

Even though risk factors associated to the HH have been proposed as a possible explanation for the increasing calendar trend of IBD incidence, their role does not appear to be statistically significant. Familial aggregation, smoking habits and appendectomy still remain the main risk factors associated with IBD.

NOD2 exonic variations in Iranian Crohn's disease patients

PURPOSE

The NOD2 gene is known to have a strong association with Crohn's disease, but different trends were reported in occurrence of NOD2 variants in distinct ethnicities. The aim of this study was to assess all exonic sequences of the NOD2 gene in Iranian Crohn's disease patients and healthy controls to identify any existing variation and evaluate their association with Crohn's disease.

METHODS

A total of 90 non-related Crohn's disease patients and 120 sex- and age-matched healthy controls of Iranian origin were enrolled in this study. The participants were referred to a tertiary center in a 2-year period (2006-2008). The exonic regions of the NOD2 gene were amplified by polymerase chain reaction and evaluated by direct sequencing.

RESULTS

A total of 21 sequence variations were identified among all exonic regions of the NOD2 gene, of which eight had an allele frequency of more than 5%. Eight new mutations (one in exon 2 and seven in exon 4) were observed. The three main variants (R702W, G908R, and 1007fs) showed allele frequencies of 13.3%, 2.2%, and 1.7%, respectively. Three new variations (P371T, A794P, and Q908H) and R702W mutation were significantly more frequent in Crohn's disease patients compared to controls.

CONCLUSIONS

Eight novel mutations were identified in the NOD2 exons, but the pathophysiological importance of these variants remains unclear. Iranian patients with their different genetic reservoirs may demonstrate some novel characteristics for disease susceptibility.

Contribution of the IBD5 locus to inflammatory bowel disease: a meta-analysis

To evaluate the association of the IBD5 locus to the predisposition of inflammatory bowel diseases (IBDs), a series of meta-analyses between five IBD5 variants (OCTN1 C1672T, OCTN2 G-207C, OCTN1/2 TC haplotype, IGR2096a_1, IGR2198a_1 and IGR2230a_1) and Crohn's disease (CD) and ulcerative colitis (UC) were performed, which included a total of 26 studies. Overall, five IBD5 variants in a per-allele model of inheritance were significantly associated with elevated CD risk (for OCTN1: OR = 1.23, 95% CI = 1.16-1.30, P < 0.001; for OCTN2: OR = 1.20, 95% CI = 1.11-1.30, P < 0.001; for IGR2096a_1: OR = 1.36, 95% CI = 1.24-1.46, P < 0.001; for IGR2198a_1: OR = 1.34, 95% CI = 1.24-1.46, P < 0.001; for IGR2230a_1: OR = 1.35, 95% CI = 1.23-1.48, P < 0.001) and OCTN1/2 TC haplotype (OR = 1.32, 95% CI = 1.22-1.43, P < 0.001). In the subgroup analysis, the statistically significant associations were also observed in adult- and pediatric-onset CD and in Caucasians for five IBD5 variants and the OCTN1/2 TC haplotype. A statistically significant increase in the risk of UC was detected in a recessive model of inheritances for OCTN1 (OR = 1.23, 95% CI = 1.08-1.40, P < 0.001), OCTN2 (OR = 1.18, 95% CI = 1.05-1.33, P = 0.006), IGR2096a_1 (OR = 1.37, 95% CI = 1.15-1.62, P < 0.001) and IGR2198a_1 (OR = 1.35, 95% CI = 1.10-1.66, P = 0.004); the increased risks of UC were maintained in the adult and Caucasian subgroups, but not the pediatric subgroup. In summary, our results suggested that the IBD5 locus contributes to the susceptibility of CD in a per-allele manner in adults, children and Caucasians, and the locus contributes to the susceptibility of UC in a recessive manner in adult and Caucasian populations.

Environmental risk factors in inflammatory bowel diseases. Investigating the hygiene hypothesis: a Spanish case-control study

OBJECTIVE

Environmental factors have been implicated in the etiology of inflammatory bowel disease (IBD), but evidence for the hygiene hypothesis is unclear. We investigated the relationship between early-life infection-related exposures and risk of IBD.

PATIENTS AND METHODS

A hospital-based case-control study was carried out. A total of 124 cases of Crohn's disease (CD) and 146 of ulcerative colitis (UC) were compared with 235 and 278 well-matched control subjects, respectively. A multi-item questionnaire on familial history of IBD, childhood circumstances and familial socioeconomic status was carried out.

RESULTS

In a multivariate model, living in urban areas (odds ratio (OR) 4.58 (95% CI 2.17-10)), high educational level (OR 1.83 (95% CI 14-2.95)) and social status (OR 1.68 (95% CI 1.2-2.35)) were risk factors for CD, whereas childhood respiratory infections (OR 0.35 (95% CI 0.23-0.52)) and gastroenteritis (OR 0.55 (95% CI 0.36-0.85)) were protective factors. Living in urban areas (OR 4.6 (95% CI 2.29-9.9)), a high educational level (OR 10.3 (95% CI 2.54-42.1)) and social status (OR 2.042 (95% CI 1.31-3.17)) were also risk factors for UC, whereas respiratory infections (OR 0.42 (95% CI 0.29-0.6)) and gastroenteritis (OR: 0.6 (95% CI 0.42-0.86)) were protective factors. Appendectomy (OR 0.173 (95% CI 0.06-0.52)) and current smoking (OR 0.75 (95% CI 0.59-0.96)) were also protective for UC.

CONCLUSION

These results further support the hypothesis that better living conditions during childhood are associated with an increased risk for IBD, and reinforce the negative association between smoking and appendectomy and the risk of UC.

Combination of innate and adaptive immune alterations increased the likelihood of fibrostenosis in Crohn's disease

BACKGROUND

Mutations in the nucleotide oligomerization domain-2 (NOD2) gene and positive antibodies to microbial antigens have been found to be associated with the Crohn's disease (CD) phenotype, fibrostenosis. The aim of this study was to confirm these relationships in a large cohort of CD patients and to determine the correlation between the presence of NOD2 variants and antibodies to oligomannan, CBir, outer membrane porin-C (OmpC), and I2 in CD patients with fibrostenosis.

METHODS

Sera and DNA from 731 unrelated CD patients were tested for NOD2 variants (SNP 8, 12, and 13) and the antibodies. The results were correlated with CD phenotypes, fibrostenosis, internal penetrating, perianal penetrating, and ulcerative colitis (UC)-like as well as other clinical features.

RESULTS

The presence of NOD2 allelic variants was primarily associated with fibrostenosis, secondarily with small bowel disease and small bowel surgery, and was inversely associated with UC-like disease. This association was present in patients with a fibrostenosis only (Vienna B2) and those with both stricturing and penetrating disease. The presence and level of antibodies to microbial antigens was also associated with the fibrostenosis phenotype. In the 316 patients with fibrostenosis the prevalence of NOD2 variants was significantly correlated with the antibody titer by quartile sum score. Further, when these patients with fibrostenosis were clustered by quartile sum score, the odds ratio for fibrostenosis was significantly higher in the patients with NOD2 variant alleles within each cluster, indicating synergy.

CONCLUSIONS

Defects of innate (NOD2 variants) and adaptive (antibodies to microbial antigens) immunity act synergistically to increase the risk of the fibrostenosis phenotype.

MicroRNAs in autoimmunity and inflammatory bowel disease: crucial regulators in immune response

MicroRNAs (miRNAs) have recently emerged as a new class of modulators of gene expression at the post-transcriptional level. The function of miRNA is the control of protein production by targeting mRNAs for translational repression or degradation. MiRNAs play a critical role in many biological processes such as cellular proliferation and maturation, apoptosis, regulation of chronic inflammation and development of cancer. It has recently been discovered that miRNAs are differentially expressed in autoimmune diseases (AID) and miRNA regulation may impact in the development or prevention of AID. In this paper we review the importance of miRNAs in AID in particular in inflammatory bowel disease (IBD). IBD is an AID whose pathophysiology remains uncertain. It is generally hypothesized that IBD is caused by the enteric microflora in genetically predisposed patients with an immune dysregulation in the gastrointestinal tract. Knowing the typical miRNA pattern of IBD will improve our knowledge of the pathogenesis of this disease and will lead to future well-focused projects to study the regulatory function of such miRNAs. Furthermore, it is possible that some miRNAs are specific to IBD and could serve as biomarkers with clinical applications for the diagnosis or assessment of disease activity.

Identification of the polymorphisms in IFITM3 gene and their association in a Korean population with ulcerative colitis

Interferons play critical roles in tumor pathogenesis by controlling apoptosis and through cellular anti-proliferative and differentiation activities. Interferon inducible transmembrane protein (IFITM) family genes have been implicated in several cellular processes such as the homotypic cell adhesion functions of IFN and cellular anti-proliferative activities. Expression levels of IFITM genes have been found to be up-regulated in gastric cancer cells and colorectal tumors. IFITM3 (also known as 1-8U) is a member of the IFITM family, and has been described as a key player in specification of germ cell fate. IFITM3 was first isolated from a genetic screen aimed at identifying genes involved in acquisition of germ cell competence. It has been proposed that epiblast cells have the highest expression of IFITM3 initiated germ cell specification and that homotypic association can discriminate germ cells from their somatic neighbors. In an attempt to better understand the genetic influences of IFITM3 on ulcerative colitis, we have identified possible variation sites and single nucleotide polymorphisms (SNPs) through two exons and their boundary IFITM3 intron sequences including the approximately 2.1 kb promoter regions. To determine whether or not these IFITM3 SNPs are associated with susceptibility to ulcerative colitis, frequencies of the genotype and allele of IFITM3 polymorphisms were analyzed on genomic DNAs isolated from patients with ulcerative colitis and from healthy controls. We also investigated the haplotype frequencies constructed by these SNPs in both groups. In this study, we also showed that expression level of IFITM3 mRNA was significantly higher in tissues of the ileum and cecum of the digestive system. We identified a total of seven SNPs and multiple variation regions in the IFITM3 gene. The genotype frequency of the g.-204T>G polymorphism in patients with ulcerative colitis was significantly different from that of the control group. Our results strongly suggest that polymorphisms of the IFITM3 gene may be associated with susceptibility to ulcerative colitis.

Dissecting genetic predisposition to inflammatory bowel disease: current progress and prospective application

Over the last 10 years, sensitive advancement has been made in the study of genetic susceptibility to inflammatory bowel disease (IBD). Complementary methodologies of linkage, fine-mapping and candidate-gene studies have led to the identification of a number of susceptibility genes and loci, including caspase activation and recruitment domain 15 (CARD15), major histocompatibility complex (MHC) and IBD5, whereas many other genes (nucleotide oligomerization domain 1 [NOD1], tumor-upregulated CARD-containing antagonist of caspase-9 [TUCAN], Toll-like receptors [TLR], interleukin 23 receptor [IL23R], multidrug resistance 1 [MDR1], myosin IXb [MYO9B], chemokine [C-Cmotif] ligand 20 [CCL20], human beta-defensin 2 [HBD-2], autophagy-related 16-like 1 [ATG16L1]) are still awaiting confirmation. The CARD15 gene is currently the most widely replicated and investigated gene. The exact sequence of events that link CARD15 variants to early pathogenetic changes is unknown. However, the role of the encoded protein confirms the relevance of appropriate responses by the innate immune system to intestinal bacteria, including the production of antimicrobial peptides (defensins). With the implementation of new genomics and proteomics methodologies, genetic research will advance our further understanding of the clinical heterogeneity of IBD and tackle the complex interactions between genetic and environmental risk factors.

Guidance for substantiating the evidence for beneficial effects of probiotics: probiotics in chronic inflammatory bowel disease and the functional disorder irritable bowel syndrome

Ulcerative colitis and Crohn's disease, the 2 distinct idiopathic pathologies of inflammatory bowel diseases, are spontaneously relapsing, immunologically mediated disorders of the gastrointestinal tract. Selected probiotics strains have been proven to be clinically effective in maintaining remission in patients with ulcerative colitis. None of the probiotics thus far tested has been shown to be effective in induction of remission or in maintenance of remission in patients with Crohn's disease. The multispecies probiotics mixture of 8 strains seems effective in the maintenance of remission in pouchitis. Irritable bowel syndrome is a functional bowel disorder manifested by chronic, recurring abdominal pain or discomfort associated with disturbed bowel habit in the absence of structural abnormalities likely to account for these symptoms. Recently conducted appropriately powered studies with different (combinations of) probiotics show positive results on reduction of symptoms, although a considerable placebo effect is also found. Mechanistic studies aimed at pathophysiological mechanisms of inflammatory bowel diseases can identify new targets for probiotic bacteria.

IL-1beta-511 and IL-1RN*2 polymorphisms in inflammatory bowel disease: An Italian population study and meta-analysis of European studies

BACKGROUND

Several studies have tried to find possible associations between genetic polymorphisms and inflammatory bowel disease prevalence and/or phenotype. Our objectives were to test the frequency and phenotypic association of two polymorphisms of the interleukin-1 pathway, IL-1beta-511 and IL-1RN*2, in inflammatory bowel disease patients and controls from an Italian population, and to compare our data with previously published similar studies in Europe.

METHODS

We screened 290 inflammatory bowel disease patients (178 ulcerative colitis and 112 Crohn's disease) and 106 controls for IL-1beta-511 and IL-1RN*2 polymorphisms by polymerase chain reaction (PCR)-based methods. The prevalence of the IL-1beta-511 and IL-1RN*2 polymorphisms in European inflammatory bowel disease patients was calculated by a meta-analysis of previously published studies using the Mantel-Haenszel method.

RESULTS

No correlation between the IL-1 polymorphisms and inflammatory bowel disease prevalence was found in our study population. Crohn's disease patients with the IL-1beta-511 mutation had a higher rate of complicated disease. A trend for an association between the IL-1RN*2 mutation and a higher risk for inflammatory bowel disease has been found only in studies with Northern European populations.

CONCLUSIONS

The IL-1beta-511 mutation can be associated with complex disease behaviour in Italian Crohn's disease patients. The IL-1RN*2 mutation may play a role in Northern European people with inflammatory bowel disease.

Identification of single nucleotide polymorphisms in the TNFRSF17 gene and their association with gastrointestinal disorders

TNFRSF17 is preferentially expressed in mature B lymphocytes, and may be important for the development of B cells. TNFRSF17 is selected as a candidate susceptibility gene to IBD pathogenesis by our cDNA microarray analysis, and we showed the specific expression of TNFRSF17 in resting and activated CD19(+) cells obtained from human blood. We identified four SNPs (g-1729G>A, g.2295T>C, g.2445G>A and g.2493G>A) and one variation site (g.894delT) in the TNFRSF17 gene using direct sequencing analysis. In addition, the association of the genotype and allelic frequencies of these SNPs was studied in healthy controls and in patients with ulcerative colitis (UC) or irritable bowel syndrome (IBS). Although, the genotype and allelic frequencies of these SNPs, in the UC and IBS patients, were not significantly different from those in the healthy controls, the distribution of the AAG, GGA, AGG and AAA haplotypes, of the SNPs (g.-1729G>A, g.2445G> A and g.2493G>A) associated with the TNFRSF17 gene, in the UC patients, were notably different from those of the healthy controls (P = 0.002, 0.002, 4.7E-4 and 3.3E-6, respectively). Moreover, the frequencies of the AAG, AGG, GAG and GAA haplotypes were significantly different in the IBS patients compared to the healthy controls (P = 4.2E-5, 4.4E-17, 1.8E-22 and 1.6E-10, respectively). These results suggest that the haplotypes of the TNFRSF17 polymorphisms might be associated with UC and IBS susceptibility.

Interleukin-27 polymorphisms are associated with inflammatory bowel diseases in a Korean population

BACKGROUND AND AIMS

The cytokine interleukin (IL)-27 is composed of two subunits, Epstein-Barr virus-induced gene 3 (EBI3) and p28, and IL-27 is a novel IL-12 family member that mediates between the innate and adaptive immune systems. We previously identified four polymorphisms in the human IL-27 gene and we suggested that the polymorphism of IL-27 is associated with the susceptibility to asthma. IL-27 transcripts are significantly elevated in active Crohn's disease (CD) but not in ulcerative colitis (UC). To determine whether these IL-27 single nucleotide polymorphisms are associated with the susceptibility to inflammatory bowel disease (IBD), the genotype and allelic frequencies of the IL-27 polymorphisms were analyzed between the IBD patients and the healthy controls.

METHODS

Genotype analysis of the IL-27 gene was performed by the single-base extension (SBE) method. The haplotype frequencies of IL-27 for multiple loci were estimated using the expectation maximization (EM) algorithm.

RESULTS

The genotype frequencies of the g.-964A > G polymorphism in the IBD patients were significantly different from those of the healthy control group (P = 0.001). In both the UC and CD patients, the genotype frequencies of the g.-964A > G polymorphism were also significantly different from the frequencies of the healthy control group (P = 0.009). The frequencies of the AGT and GGT haplotypes were significantly different between the healthy control group and the IBD patient group (P = 0.00004 and 0.021, respectively).

CONCLUSION

Our results suggest that the g.-964A > G polymorphism of the IL-27 gene located on the IBD1 locus might be associated with the susceptibility to IBD.

Differential expression of leukocyte functions associated antigen-1 (LFA-1) on peripheral blood mononuclear cells in patients with Crohn's disease

BACKGROUND

The leukocyte function associated antigen-1 (LFA-1) intracellular adhesion molecule-1 pathway is presumed to play a pivotal role in the perpetuation of inflammatory bowel disease. We aimed to elucidate the effect of 2 different therapies on LFA-1 expression in patients with Crohn's disease (CD) and correlate LFA-1 expression with disease activity.

METHODS

In all, 30 patients with active CD were recruited for the present investigation. Eleven patients were treated with infliximab and 19 patients with total parenteral nutrition. The clinical activity and the expression of LFA-1 in peripheral blood mononuclear cells were assessed prior to and 4 weeks after treatment. Clinical activity was determined by measuring the Crohn's Disease Activity Index and LFA-1 expression was measured by mean fluorescence intensity (MFI) under fluorescence-activated cell sorter analysis.

RESULTS

In each treatment group the clinical disease activity index decreased significantly 4 weeks after treatment. In patients treated with infliximab, LFA-1 expression decreased significantly (mean MFI decreased from 1983 to 1487, P < 0.05). However, LFA-1 expression remained unchanged in the total parenteral nutrition group (mean MFI elevated from 1684 to 1902, P > 0.05).

CONCLUSIONS

The mechanism of therapeutic action on CD is different between infliximab and total parenteral nutrition.

[Inflammatory bowel disease: genetic or environmental diseases?]

Pathophysiology of inflammatory bowel diseases depends on the interaction between genetic susceptibility and environmental factors leading to a deregulated immune intestinal response resulting in bowel lesions. Epidemiologic variations of inflammatory bowel diseases with time (incidence, prevalence) and space suggest a role for risk environmental factors, but so far only smoking habits and appendectomy have been identified as influencing the risk of occurrence and the course of the diseases. Studies of monozygotic and dizygotic twins and the existence of familial aggregation are strong evidence for an important, but not exclusive, role for genetic susceptibility. Since the discovery of NOD2/CARD15 mutations, numerous genes have been associated with inflammatory bowel diseases, some of them involved in the regulation of innate immunity and cellular clearance of infectious agents (autophagy). Thus, new hypothesis include a key role of mucosal human microbiota which could be partly influenced by environmental factors generated by modern life. The improvement of life hygiene, the change of food composition and habits, the industrial pollution in developed countries, may influence, directly or by the way of modifying intestinal human microbiota, inflammatory bowel diseases risk occurrence.

Tolllike receptor 4 (TLR4) polymorphisms in Tunisian patients with Crohn's disease: genotype-phenotype correlation

Background

The immune responses to bacterial products through the pattern recognition receptor (PRR) play a pivotal role in pathogenesis of Crohn's disease. A recent study described an association between CD and some gene coding for bacterial receptor like NOD2/CARD15 gene and TLR4. In this study, we sought to determine whether TLR4 gene was associated with Crohn's disease (CD) among the Tunisian population and its correlation with clinical manifestation of the disease.

Methods

90 patients with CD and 80 healthy individuals are genotyped for the Asp299Gly and Thr399Ile polymorphisms by restriction fragment length polymorphism analysis.

Results

The allele and genotype frequency of the TLR4 polymorphisms did not differ between patients and controls. The genotype-phenotype correlation permitted to show that the Thr399Ile polymorphism was associated with early onset disease.

Conclusion

this study reported the absence of association between CD and TLR4 gene in the Tunisian population, but this gene could play a role in clinical expression of the disease.

The natural history of pediatric ulcerative colitis: a population-based cohort study

OBJECTIVES

The natural history of ulcerative colitis (UC) has been poorly described in children.

METHODS

In a geographically derived incidence cohort diagnosed from 1988 to 2002, we identified 113 UC patients (age 0-17 years at diagnosis) with a follow-up of at least 2 years. The cumulative risk of colectomy was estimated by the Kaplan-Meier method. Risk factors for disease extension were assessed with logistic regression models, and risk factors for colectomy with Cox hazards proportional models.

RESULTS

Median follow-up time was 77 months (46-125). At diagnosis, 28% of patients had proctitis, 35% left-sided colitis, and 37% extensive colitis. Disease course was characterized by disease extension in 49% of patients. A delay in diagnosis of more than 6 months and a family history of inflammatory bowel disease were associated with an increased risk of disease extension, with odds ratios of 5.0 (1.2-21.5) and 11.8 (1.3-111.3), respectively. The cumulative rate of colectomy was 8% at 1 year, 15% at 3 years, and 20% at 5 years. The presence of extra-intestinal manifestations (EIMS) at diagnosis was associated with an increased risk of colectomy (hazard ratio (HR)=3.5 (1.2-10.5)). Among the patients with limited disease at diagnosis, the risk of colectomy was higher in those who experienced disease extension than in those who did not (HR=13.3 1.7-101.7).

CONCLUSIONS

Pediatric UC was characterized by widespread localization at diagnosis and a high rate of disease extension. Twenty percent of children had their colon removed after 5 years. The colectomy rate was influenced by disease extension and was associated with the presence of EIMS at diagnosis.

Blockage of the neurokinin 1 receptor and capsaicin-induced ablation of the enteric afferent nerves protect SCID mice against T-cell-induced chronic colitis

BACKGROUND

The neurotransmitter substance P (SP) released by, and the transient receptor potential vanilloid (TRPV1), expressed by afferent nerves, have been implicated in mucosal neuro-immune-regulation. To test if enteric afferent nerves are of importance for the development of chronic colitis, we examined antagonists for the high-affinity neurokinin 1 (NK-1) SP receptor and the TRPV1 receptor agonist capsaicin in a T-cell transfer model for chronic colitis.

METHODS

Chronic colitis was induced in SCID mice by injection of CD4(+)CD25(-) T cells. The importance of NK-1 signaling and TRPV1 expressing afferent nerves for disease development was studied in recipient SCID mice systemically treated with either high-affinity NK-1 receptor antagonists or neurotoxic doses of capsaicin. In addition, we studied the colitis-inducing effect of NK-1 receptor deleted CD4(+)CD25(-) T cells.

RESULTS

Treatment with the NK-1 receptor antagonist CAM 4092 reduced the severity of colitis, but colitis was induced by NK-1 receptor-deleted T cells, suggesting that SP in colitis targets the recipient mouse cells and not the colitogenic donor T cells. Capsaicin-induced depletion of nociceptive afferent nerves prior to CD4(+)CD25(-) T-cell transfer completely inhibited the development of colitis.

CONCLUSIONS

Our data demonstrate the importance of an intact enteric afferent nerve system and NK-1 signaling in mucosal inflammation and may suggest new treatment modalities for patients suffering from inflammatory bowel disease.

Enterococcus faecalis strains differentially regulate Alix/AIP1 protein expression and ERK 1/2 activation in intestinal epithelial cells in the context of chronic experimental colitis

Monoassociation of germfree Interleukin 10 gene deficient (IL-10-/-) 129SvEv but not wild-type mice with Enterococcus faecalis induces severe chronic colitis. Bacterial strain-specific effects on the development of chronic intestinal inflammation are not understood. We investigated the molecular mechanisms of E. faecalis OG1RF (human clinical isolate, colitogenic) and E. faecalis ms2 (endogenous isolate from an IL-10-/- mouse) in initiating chronic experimental colitis using IL-10-/- mice. Monoassociation of IL-10-/- mice for 14 weeks revealed significant differences in colonic inflammation (3.6 +/- 0.2 and 2.4 +/- 0.6 for OG1RF and ms2, respectively) (n = 5 mice in each group) (histological scoring (0-4)). Consistent with the tissue pathology, gene expression of the pro-inflammatory chemokine interferon-gamma inducible protein-10 (IP-10) was significantly higher in intestinal epithelial cells (IEC) derived from E. faecalis OG1RF monoassociated IL-10-/- mice. We further compared the differentially E. faecalis induced colitis on the epithelial level by 2D-SDS PAGE coupled with MALDI-TOF MS. Proteome analysis identified 13 proteins which were differentially regulated during disease progression in the epithelium of E. faecalis-monoassociated IL-10-/- mice. Regulation of Alix/AIP1 protein expression and ERK1/2 phosphorylation was validated in primary IEC and epithelial cell lines, suggesting a protective role for Alix/AIP1 in the process of disease progression. Alix/AIP1 protein expression was further characterized in epithelial cell lines using siRNA-mediated knock-down. Our study demonstrates E. faecalis strain-specific induction of colitis in IL-10-/- mice after 14 weeks of monoassociation. Our study suggests that Alix/AIP1 protein expression and ERK1/2 activation are decreased in severe colitis.

Mannan-binding lectin B allele is associated with a risk of developing more severe gastric mucosal atrophy in Helicobacter pylori-infected Japanese patients

OBJECTIVE

Mannan-binding lectin (MBL) is an important constituent of the innate immune system, and deficiency of MBL has been reported to increase the overall susceptibility of an individual to infectious disease. Codon 54 G/A variant of exon 1 (B allele) affects MBL2 gene and alters its activity. We investigated the influence of MBL2 variant on the risk of gastroduodenal diseases and on the severity of Helicobacter pylori-induced gastritis in a Japanese population.

METHODS

One hundred and two gastric ulcers, 48 duodenal ulcers, 275 nonulcer participants were included in this study. B allele of the MBL2 gene was detected by polymerase chain reaction based restriction fragment length polymorphism. The severity of the histological chronic gastritis in antral biopsy specimens were classified according to the updated Sydney system.

RESULTS

MBL2 B allele was significantly associated with severity of gastric mucosal atrophy and intestinal metaplasia (atrophy, G/G vs. G/A vs. A/A; P=0.02, A/A vs. others; P=0.009, intestinal metaplasia; G/G vs. G/A vs. A/A; P=0.03, A/A vs. others; P=0.004). When participants were divided into the following three groups according to the severity of gastric atrophy: the nonatrophic gastritis (NA) group, the severe atrophic gastritis (SA) group, and mild atrophic gastritis (MA) group, the frequency of A/A was significantly higher in the SA group than in others (SA vs. MA; odds ratio=8.42, 95% confidence interval=1.05-67.45, SA vs. others; odds ratio=10.06, 95% confidence interval=1.26-80.45).

CONCLUSION

Our data suggest that the MBL2 codon 54 B allele is associated with a risk of developing more severe gastric mucosal atrophy in H. pylori-infected Japanese patients.

Metabolic assessment of gradual development of moderate experimental colitis in IL-10 deficient mice

Evidence has linked genetic predisposition and environmental exposures to the worldwide pandemic of inflammatory bowel diseases (IBD), but underlying biochemical events remain largely undefined. Here, we studied the gradual development of colitis in Interleukin 10 deficient mice using a combination of (i) histopathological analysis of intestinal sections, (ii) metabolic profiling of blood plasma, and (iii) measurement of plasma inflammatory biomarkers. Data integration using chemometric tools, including Independent Component Analysis, provided a new strategy for measuring and mapping the metabolic effects associated with the development of intestinal inflammation at the age of 1, 8, 16, and 24 weeks. Chronic inflammation appeared at 8 weeks and onward, and was associated with altered cecum and colon morphologies and increased inflammatory cell infiltration into the mucosa and the submucosa. Blood plasma profiles provided additional evidence of loss of energy homeostasis, impaired metabolism of lipoproteins and glycosylated proteins. In particular, IL-10-/-mice were characterized by decreased levels of VLDL and increased concentrations of LDL and polyunsaturated fatty acids, which are related to the etiology of IBD. Moreover, higher levels of lactate, pyruvate, citrate and lowered glucose suggested increased fatty acid oxidation and glycolysis, while higher levels of free amino acids reflected muscle atrophy, breakdown of proteins and interconversions of amino acids to produce energy. These integrated system investigations demonstrate the potential of metabonomics for investigating the mechanistic basis of IBD, and it will provide novel avenues for management of IBD.

Enteropathic spondyloarthropathy: A common genetic background with inflammatory bowel disease?

The association between spondyloarthropathy and inflammatory bowel disease (IBD) is largely established, although prevalence is variable because of different population selection and diagnostic methodologies. Most studies indicate that as many as 10%-15% of cases of IBD are complicated by ankylosing spondylitis (AS) or other forms of spondylarthritis (SpA). Of note, ileal inflammation resembling IBD has been reported in up to two thirds of cases of SpA, and it has been suggested that the presence of ileitis is associated with the chronicity of articular complications. Although this observation is of interest to unravel the pathophysiology of the disease, systematic screening of patients with SpA by ileocolonoscopy is not indicated in the absence of gut symptoms, as only a small proportion of patients with subclinical gut inflammation will develop overt IBD over time. The existence of familial clustering of both IBD and AS, the coexistence of both conditions in a patient, the evidence of an increased risk ratio among first- and second-degree relatives of affected AS or IBD patients and finally, the increased cross-risk ratios between AS and IBD, strongly suggest a shared genetic background. So far, however, IL23R is the only identified susceptibility gene shared by both IBD and AS. Although functional studies are still needed to better understand its pathogenic role, great effort is being spent therapeutically targeting this pathway that may prove effective for both disorders.

Polymorphisms of PTPN11 coding SHP-2 as biomarkers for ulcerative colitis susceptibility in the Japanese population

OBJECTIVE

To identify genetic determinants of inflammatory bowel disease (IBD), we examined an association between polymorphisms of both the programmed cell death 1 gene (PDCD1) and the src homology 2 domain-containing tyrosine phosphatase 2 gene (PTPN11) and susceptibility to IBD.

METHODS

Study subjects comprised 114 patients with ulcerative colitis (UC), 83 patients with Crohn's disease, and 200 healthy control subjects. Five single nucleotide polymorphisms (SNPs) in PDCD1 and PTPN11 were detected by polymerase chain reaction restriction fragment length polymorphism. Subsequently, haplotypes composed of the two SNPs in PTPN11 were constructed.

RESULTS

The frequencies of the Hap 1 haplotype and its homozygous Hap 1/Hap 1 diplotype of PTPN11 were significantly increased in UC patients compared to control subjects (P = 0.011 and P = 0.030, respectively). While no association was found for PDCD1 for UC or CD and none for PTPN11 for CD.

CONCLUSION

PTPN11 is a genetic determinant for the pathogenesis of UC, and haplotyping of PTPN11 may be useful as a genetic biomarker to identify high-risk individuals susceptible to UC.

Alternative medicine products as a novel treatment strategy for inflammatory bowel disease

Inflammatory bowel disease (IBD) affects the mucosal lining of the gastrointestinal tract; the etiology is unknown and treatment is directed at systemic immunosuppression. Natural products, including medicinal herbs, have provided approximately half of the drugs developed for clinical use over the past 20 years. The purpose of our current study was to determine the effects of a novel combination of herbal extracts on intestinal inflammation using a murine model of IBD. Female Swiss-Webster mice were randomized to receive normal water or 5% dextran sulfate sodium (DSS) drinking water to induce colitis. Mice were treated with either a novel combination of herbal aqueous extracts or vehicle control per os (po) or per rectum (pr) every 24 hours for 7-8 days. Disease activity index score (DAI) was determined daily; mice were sacrificed and colons were analyzed by H & E staining, MPO assay, and cytokine (TNF-alpha, IL-6) ELISAs. Mice treated with the combination of herbal extracts, either po or pr, had significantly less rectal bleeding and lower DAI scores compared to the vehicle-treated group. Moreover, colonic ulceration, leukocytic infiltration, and cytokine levels (TNF-alpha and IL-6) were also decreased in the colons of herbal-treated mice, reflected by H & E staining, MPO assay, and cytokine ELISA. Treatment with the combination of medicinal herbs decreases leukocyte infiltration and mucosal ulceration, ameliorating the course of acute colonic inflammation. This herbal remedy may prove to be a novel and safe therapeutic alternative in the treatment of IBD.

Association of vitamin D receptor gene polymorphisms in Iranian patients with inflammatory bowel disease

BACKGROUND AND AIMS

The vitamin D receptor (VDR) gene maps to a region on chromosome 12 shown to be linked to inflammatory bowel disease (IBD). Many studies have recognized the relation of VDR gene polymorphisms with inflammatory and autoimmune disorders. Determining the frequency of these polymorphisms and their possible relation with IBD can improve understandings about the genetic background of these diseases. The objective of this study was to assess the association of VDR gene polymorphisms (Apa I, Taq I, Bsm I, Fok I) with IBD in Iran.

METHODS

In this case control designed study 150 patients with ulcerative colitis, 80 patients with Crohn's disease and 150 Age and Sex matched healthy controls from Iranian origin were enrolled. These patients were referred to a tertiary center during a two-year period (2004-2006). Assessment of VDR gene polymorphisms was performed by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The genotype-phenotype association for these polymorphisms was analyzed.

RESULTS

Only the frequency of the Fok I polymorphism was significantly higher in ulcerative colitis and Crohn's groups. The frequency of the polymorphic allele f was higher in ulcerative colitis and Crohn's patients comparing with controls (P = 0.011 and P < 0.001, respectively). The f/f genotype was also significantly more frequent (P < 0.001), while the F/F genotype was less presented in Crohn's patients compared to controls (P < 0.001). No genotype-phenotype association was observed with any mutations.

CONCLUSIONS

This study suggests a probable association of the Fok I polymorphism in VDR receptor gene and Crohn's susceptibility in Iranian population.

Role of major histocompatibility complex class I-related molecules A*A5.1 allele in ulcerative colitis in Chinese patients

The major histocompatibility complex (MHC) class I-related molecules A (MICA) is a stress-inducible cell surface antigen that is recognized by intestinal epithelial Vdelta1 gammadelta T cells, natural killer (NK) cells and CD8(+) T cells with NKG2D receptor participating in the immunological reaction in the intestinal mucosa. The present study aimed to investigate the functions of the MICA*A5.1 allele in the development of ulcerative colitis (UC) in the Chinese population. The microsatellite polymorphisms of MICA were genotyped in 124 unrelated Chinese patients with UC and 172 ethnically matched healthy controls using a semiautomatic fluorescently labelled polymerase chain reaction. MICA*A5.1-expressing Raji cells were generated by gene transfection. Cytotoxicity of NK cells to Raji cells expressing different MICA molecules was detected using the lactate dehydrogenase method. Soluble MICA in the culture supernatant was detected by enzyme-linked immunosorbent assay. The frequency of MICA*A5.1 was significantly higher in UC patients compared with the healthy controls (29.0% versus 17.4%, P = 0.001, corrected P = 0.005, OR = 1.936, 95% CI 1.310-2.863) and the frequency of a MICA*A5.1/A5.1 homozygous genotype was increased in UC patients (18.5% versus 7% in healthy controls, P = 0.0032, corrected P = 0.048, OR = 3.036, 95% CI 1.447-6.372). Raji cells with MICA*A5.1 expression produced more soluble MICA (t = 5.75, P < 0.01) than Raji cells with full-length MICA expression in culture supernatant. Raji cells with MICA*A5.1 expression were more resistant to killing by NK cells than Raji cells with full-length MICA expression. The MICA*A5.1 allele and MICA*A5.1/A5.1 genotype are significantly associated with Chinese UC patients in central China. MICA*A5.1 may play a role in the development of UC by producing more soluble MICA and resistance to NK cells.

Mannan-binding lectin (MBL) polymorphism and gastric cancer risk in Japanese population

BACKGROUND

Mannan-binding lectin (MBL) is believed to be an important constituent of the innate immune system. It has been reported that the codon 54 G/A polymorphism of exon-1 affects the MBL2 gene and alters its activity.

AIMS

We investigated the association between polymorphism of the MBL2 gene and gastric cancer risk as well as Helicobacter pylori infection in a Japanese population.

METHODS

The study cohort comprised 388 gastric cancer patients and 144 healthy volunteers. Polymorphism at codon 54 of exon 1 of the MBL2 gene was investigated by PCR-based restriction fragment length polymorphism analysis.

RESULTS

There was no significant difference in the distribution of the MBL2 genotype among the gastric cancer patients and healthy controls. However, the carrier of the A allele was more prevalent among patients with a more advanced stage gastric cancer [odds ratio (OR) 1.68, 95% confidence interval (CI) 1.05-2.67; P = 0.03] and also had an increased risk of gastric cancer among patients 65 years of age or younger (OR = 1.6, 95%CI = 1.01-2.52, <0.05).

CONCLUSION

The codon 54 polymorphism of the MBL2 gene is associated with more advanced phenotypes of gastric cancer and the risk of gastric cancer in Japanese patients 65 years of age or younger.

CARD15 gene polymorphisms in Serbian patients with Crohn's disease: genotype-phenotype analysis

OBJECTIVE

Genetic heterogeneity and incomplete phenotype penetrance complicate genetic analysis of Crohn's disease (CD). Studies in western Europe have shown that CARD15 polymorphisms increase susceptibility to CD, but frequencies vary within different European populations. The aim here was to evaluate the prevalence of CARD15 mutations and their phenotypic correlation in a Serbian population.

MATERIALS AND METHODS

131 patients with CD, 65 patients with ulcerative colitis, and 88 healthy controls were genotyped for three common mutations (R702W, G908R, Leu1007insC) by PCR-restriction fragment length polymorphism. chi and Student's t-test were used for statistical assessment.

RESULTS

At least one CARD15 disease-associated allele was found in 35.11% patients with CD, 14.77% of healthy controls (P=0.001), and 7.69% patients with ulcerative colitis (P=0.0001). The L1007fs mutation showed a significant association with CD (P<0.0001). The frequency of R702W mutant allele was almost equal in the control group and CD patients Univariate analyses established that CARD15 carriers had a significantly higher risk of isolated ileal location [P=0.042; odds ratio (OR) 2.30; 95% confidence interval (CI): 1.02-5.19], fibrostenotic behavior (P<0.0001; OR 9.86; 95% CI: 4.29-22.62), surgical resection (P=0.036; OR 2.2; CI, 1.046-4.626), and earlier onset of disease (P=0.026).

CONCLUSION

This study confirms that CARD15 carriers, especially L1007fs mutants, in central Europeans have an increased risk of CD and it is associated with earlier onset, ileal, fibrostenotic disease and a higher risk of surgery. Any influence of latitude is not matched by an east-west divide on the genotype frequency and phenotype of CD within Europe.

The V249I polymorphism of the CX3CR1 gene is associated with fibrostenotic disease behavior in patients with Crohn's disease

OBJECTIVES

CX3CR1, the receptor of CX3CL1/fractalkine, is involved in regulation of inflammatory response and the CX3CR1-I249-M280 naturally occurring mutants are associated with altered binding to the ligand. Our aim was to evaluate the frequency of CX3CR1 V249I and T280M polymorphisms and NOD2/CARD15 mutations in Crohn's disease patients and to search for a relationship with phenotype.

METHODS

Clinical data were retrospectively collected. V249I and T280M polymorphisms of CX3CR1 gene and NOD2/CARD15 mutations (R702W, G908R, 3020InsC) were identified.

RESULTS

Two hundred and thirty-nine patients (140 females, 39.7+/-14.1 years) were included. About 37.4% were heterozygous and 8.8% were homozygous for the V249I CX3CR1 polymorphism, 18.1% were heterozygous and 1.3% homozygous for the T280M CX3CR1 polymorphism and 35.9% had at least one of the three mutations of NOD2/CARD15. The T280M CX3CR1 polymorphism was not associated with any phenotype. In univariate analysis, stenosis was significantly associated with both V249I CX3CR1 polymorphism and 3020InsC NOD2/CARD15 mutations. In smoker patients carrying the CX3CR1 allele I249, there was a significant increase in the frequency of fibrostenosing disease [P=0.005, odds ratio (OR): 3.25] whereas this relationship disappeared in the group of nonsmokers (P=0.72). In multivariate analysis, 3020InsC NOD2/CARD15 mutations and the V249I CX3CR1 polymorphism were independent risk factors for intestinal stenosis (P=0.046, OR: 1.8 and P=0.044, OR: 2.4, respectively).

CONCLUSION

In Crohn's disease, V249I CX3CR1 polymorphism is associated with intestinal strictures, particularly in smokers. This association is independent of CARD15 mutations.