Role of the innate immune system in the pathogenesis of inflammatory bowel disease

Triple-Functional Probiotics with Intracellularly Synthesized Selenium Nanoparticles for Colitis Therapy by Regulating the Macrophage Phenotype and Modulating Gut Microbiota

The dysregulated macrophage phenotype, as the main cause of colitis, not only enhanced oxidative stress to exacerbate inflammatory responses but was closely related with gut microbial dysbiosis. It was needed to simultaneously address the three issues for the effective treatment of colitis, but it was not satisfied. Here, we developed "three-birds-one-stone" probiotics, named Se@EcN-C2/A2, for colitis treatment. Escherichia coli Nissle 1917 (EcN), a clinically approved probiotic, was used to intracellularly synthesize selenium (Se) nanoparticles by biomineralization, giving Se@EcN. Coating glycol chitosan and sodium alginate on the surface of Se@EcN (Se@EcN-C2/A2) endowed probiotics with high resistance to the harsh gastrointestinal tract environment and strong adhesion and targeting ability to the inflamed site of the colon to facilitate the uptake by M1 macrophages. Se@EcN-C2/A2 was metabolized to SeCys2 and MetSeCys to be involved in the synthesis of GPX2 and TXNRD1, which led to reaction oxygen species clearance to inhibit Toll-like receptor and nuclear factor κB signaling pathways to suppress inflammatory response and polarize M1 macrophages to M2 phenotypes by activating PI3K/AKT signaling pathways. In DSS-induced colitis mice, Se@EcN-C2/A2 exerted satisfactory therapeutic and prophylactic effects, including scavenging oxidative stress and regulating macrophage phenotypes to suppress inflammatory response and restore gut barrier functions. Moreover, the living probiotic EcN in the colon effectively regulated microbial dysbiosis by decreasing the abundance of Escherichia-Shigella and increasing the abundance of Lactobacillus and Bifidobacterium.

The Combined Administration of Eicosapentaenoic Acid (EPA) and Gamma-Linolenic Acid (GLA) in Experimentally Induced Colitis: An Experimental Study in Rats

Background/Objectives: Ulcerative colitis (UC) is a chronic inflammatory bowel disease with limited effective treatments, prompting the need for investigation of novel therapeutic approaches. Eicosapentaenoic acid (EPA) and gamma-linolenic acid (GLA) have demonstrated potential anti-inflammatory properties, but their combined effects on UC have not been thoroughly investigated. This study aimed to evaluate the effect of the combined administration of EPA and GLA on clinical and histopathologic features of experimental UC models. Methods: Thirty-six male Wistar rats were randomized in three groups (DSS group, Ensure Plus group, and Oxepa group), with twelve rats in each group. Experimental colitis was induced by administrating dextran sulfate sodium (DSS) 8%. The DSS group received tap water, the Ensure Plus group was given a high caloric diet, and the Oxepa group received a special diet containing high levels of EPA and GLA. Disease activity index (DAI) and microscopic activity index (MAI) were measured. Inflammatory markers were calculated both in blood and large intestine, liver, spleen, and lung tissue samples. Neutrophil and macrophage populations were assessed with immunohistochemistry. Results: No significant differences in the DAI index were found between the groups, but the MAI revealed statistically significant differences (p < 0.001). While no significant differences were observed in tumor necrosis factor-alpha (TNF-α) levels, interleukin-17 (IL-17) levels in the large intestine showed statistically significant differences (p = 0.05), with the Ensure Plus and Oxepa groups displaying lower levels compared to the DSS group (p = 0.021 and p = 0.043, respectively). Significant differences in neutrophil infiltration were found in both the large intestine (p < 0.001) and lungs (p = 0.002), with the Oxepa group showing fewer cells. Similarly, significant differences in macrophage infiltration were observed in the large intestine (p = 0.038) and spleen (p < 0.001), with the Oxepa group having lower macrophage counts. Conclusions: In conclusion, the combination of EPA and GLA demonstrates local anti-inflammatory effects and improves the histopathological outcomes in UC.

17β-estradiol promotes myeloid-derived suppressor cells functions and alleviates inflammatory bowel disease by activation of Stat3 and NF-κB signalings

Inflammatory bowel disease (IBD) describes a group of clinically common autoimmune diseases characterized by chronic intestinal inflammation, with gender differences in prevalence. Estrogen has been previously shown to exert anti-inflammatory action in IBD development, however, the mechanisms remain obscure. Recent research has revealed that myeloid-derived suppressor cells (MDSCs) play a protective role in IBD pathogenesis. To investigate the molecular mechanisms of estrogen steroid 17β-estradiol (E2) in IBD progression, we established IBD mouse models (DNB-induced) with or without prior ovariectomy (OVX) and E2 implantation. We found that OVX led to worse IBD symptoms and reduced MDSCs frequency, whereas E2 significantly alleviated these effects in vivo. Moreover, in vitro experiments showed that E2 promoted the proliferation and immunosuppressive function of MDSCs through phosphorylation of Stat3 and p65. Mechanistically, E2-mediated Stat3/p65 phosphorylation depends on the interaction between HOTAIR, a long non-coding RNA that are well-known in MDSCs proliferation, and Stat3/p65 respectively. In conclusion, our study revealed that E2 promotes the expansion and immunosuppressive function of MDSCs, and thus diminished the occurrence and development of IBD.

Evaluating the causal association between bronchiectasis and different types of inflammatory bowel disease: a two-sample Mendelian randomization study

Background and objectives

Previous observational studies have established a connection between bronchiectasis and inflammatory bowel disease (IBD), but none of these studies have provided a clear explanation for the underlying cause of this relationship. The present study thus implemented Mendelian randomization (MR) design to explore possible bidirectional relationships between IBD and bronchiectasis risk, with an additional focus on Crohn's disease (CD) and ulcerative colitis (UC) as IBD subtypes.

Materials and methods

A large genome-wide association study (GWAS)-derived data pool was leveraged to examine the relationships between bronchiectasis and IBD, CD, and UC. Two-sample MR analyses were performed with an inverse variance weighted (IVW) approach supplemented with the MR-Egger and weighted median methods. Sensitivity analyses were used to further assess the reliability of the main MR study findings. The possibility of reverse causation was also evaluated using a reverse MR approach.

Results

The IVW MR analytical approach revealed that IBD (p = 0.074), UC (p = 0.094), and CD (p = 0.644) had no significant impact on the incidence of bronchiectasis, with the converse also being true (p = 0.471, p = 0.700, and p = 0.099, respectively).

Conclusion

This MR analysis demonstrated that the higher occurrence of bronchiectasis in patients with IBD is not caused by genetic predisposition.

Case report: Confusing lung signs - is the source of the disease in the lungs or intestines?

At the time of the spread of the COVID-19 epidemic, blurred lung signs suggested by imaging examination are particularly common. Novel coronavirus infection is mainly caused by respiratory symptoms. In the early stage of imaging examination, multiple small patchy shadows or ground glass shadows and invasive shadows of both lungs are dominant. While the pulmonary involvement in Crohn's disease (CD) is rare and not widely reported. For CD patients, the pulmonary manifestations do not belong to its routine symptoms. The lung involvement of CD patients is difficult to attract clinicians' attention. If CD patients have vague lung manifestations but have no response to routine treatment, they should consider the respiratory diseases related to CD. We describe a rare case of granulomatous inflammation associated with Crohn's disease. The patient do not respond to conventional treatment. The final treatment plan was CD immunomodulatory therapy (oral corticosteroids and azathioprine). After treatment, a review of the lung CT showed focal fibrosis and significant improvement in the lung lesions. It suggests that CD related respiratory diseases should be considered when CD patients have abnormal lung manifestations that do not respond to conventional treatment.

Emerging Role of Extracellular Vesicles in Biomarking the Gastrointestinal Diseases

INTRODUCTION

Extracellular vesicles (EVs) play an important role in cell-cell communication and regulation of various cellular functions under physiological and pathophysiological conditions through transferring their cargo to recipient cells. Molecular constituents of EVs are a fingerprinting profile of secreting cells which can be used as promising prognostic, diagnostic, and drug-response biomarkers in clinical settings.

AREAS COVERED

The present study provides a brief introduction about the biology of EVs and reviews methodologies used for EV isolation and characterization as well as high-throughput strategies to analyze EV contents. Furthermore, this review highlights the importance and unique role of EVs in the development and progression of gastrointestinal (GI) diseases, especially GI cancers, and then discusses their potential use, particularly those isolated from body fluids, in diagnosis and prognosis of GI diseases.

EXPERT OPINION

In-depth analysis of EV content can lead to the identification of new potential biomarkers for early diagnosis and prognosis prediction of GI diseases. The use of a more targeted approach by establishing more reproducible and standardized methods to decrease variations and obtain desired EV population as well as revisiting large pools of identified biomarkers and their evaluation in larger patient cohorts can result in the introduction of more reliable biomarkers in clinic.

Crohn's disease with pulmonary granuloma in a child: a case report and review of the literature

Crohn's disease (CD) is a chronic granulomatous disease that affects the gastrointestinal system. Additionally, CD has multiple extraintestinal manifestations, and bronchopulmonary manifestations are extremely rare. Pulmonary lesions can occur before the diagnosis of CD; thus, pulmonary manifestations are often overlooked, which leads to misdiagnoses. Herein, we present a case with pulmonary nodules being exhibited before the patient was diagnosed with CD. To the best of our knowledge, only a few cases concerning this phenomenon have been reported. We describe an 11-year-old boy with a two-year history of anemia and without any gastrointestinal symptoms. He did not receive any thorough inspection until arthralgia occurred. Multiple nodules were found in his bilateral lungs via computed tomography scan. Combined with the child's medical history, physical examinations, and all of the investigations, the final diagnosis was CD with pulmonary nodules and arthritis. After 2 months of treatment, the patient's symptoms had significantly improved. To summarize the clinical manifestations, auxiliary examination features, and treatments of CD in children with pulmonary involvement, we also review the relevant characteristics of pulmonary involvement in CD patients. This case indicates the importance of recognizing the pulmonary manifestations of CD. Clinicians should be aware of the possibility of CD when their patients have lung nodules, even in children with no typical manifestations of CD.

Assessment of Occult Pulmonary Involvement in Ulcerative Colitis

INTRODUCTION

Nearly 50% of patients with inflammatory bowel disease (IBD) experience at least one extraintestinal manifestation. Bronchopulmonary involvement is rare in IBD. Pulmonary function test (PFT) abnormality in cases of ulcerative colitis (UC) has been reported to be 17-55%. Occult pulmonary disease may be diagnosed using variables of the PFT. Hence, we aim to evaluate the frequency and type of pulmonary dysfunction in patients with UC in remission.

METHODS

Eighty-three patients of UC in remission and 48 controls underwent the PFT including forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), Tiffeneau value (FEV1/FVC), and midexpiratory flow (MEF 25-75%) rate with a spirometer. The patients were divided based on the age of onset of UC into A1 (<16 years), A2 (16-40 years), and A3 (>40 years) and based on the extent of disease into E1 (proctitis), E2 (left-sided colitis), and E3 (extensive colitis).

RESULTS

Patients with UC had significantly abnormal PFT compared with controls (51 [61.5%] vss. 8 [16.67%]; p = 0.000). Patients with UC commonly had a restrictive pattern (33 [64.47%]) of PFT followed by small airway disease (11 [21.56%]) and obstructive pattern (7 [13.72%]). Pulmonary involvement in cases of UC was more in E3 followed by E2 and E1. Pulmonary involvement was more in the late age of onset of disease. BMI was positively and significantly correlated with FEV1 and FVC. Hemoglobin had a positive and significant correlation with FEV1 while a negative correlation with FEV1/FVC and MEF 25-75%. All predictors except for age were found to contribute in higher risk (OR > 1) for PFT abnormality.

CONCLUSION

Patients with UC have chronic pulmonary inflammation leading to different patterns of lung involvement in the form of restrictive, obstructive airway, and small airway disease. Patients with UC commonly have a restrictive pattern of pulmonary involvement. Impairment of the PFT is related to the disease extent and the age of onset of disease. Assessment of the PFT using a spirometer is a noninvasive, simple, cost-effective, and reliable method for early detection of occult pulmonary involvement in patients of UC.

Paediatric and adult bronchiectasis: Specific management with coexisting asthma, COPD, rheumatological disease and inflammatory bowel disease

Bronchiectasis, conventionally defined as irreversible dilatation of the bronchial tree, is generally suspected on a clinical basis and confirmed by means of chest high-resolution computed tomography. Clinical manifestations, including chronic productive cough and endobronchial suppuration with persistent chest infection and inflammation, may deeply affect quality of life, both in children/adolescents and adults. Despite many cases being idiopathic or post-infectious, a number of specific aetiologies have been traditionally associated with bronchiectasis, such as cystic fibrosis (CF), primary ciliary dyskinesia or immunodeficiencies. Nevertheless, bronchiectasis may also develop in patients with bronchial asthma; chronic obstructive pulmonary disease; and, less commonly, rheumatological disorders and inflammatory bowel diseases. Available literature on the development of bronchiectasis in these conditions and on its management is limited, particularly in children. However, bronchiectasis may complicate the clinical course of the underlying condition at any age, and appropriate management requires an integration of multiple skills in a team of complementary experts to provide the most appropriate care to affected children and adolescents. The present review aims at summarizing the current knowledge and available evidence on the management of bronchiectasis in the other conditions mentioned and focuses on the new therapeutic strategies that are emerging as promising tools for improving patients' quality of life.

Pulmonary Involvement in Crohn's Disease: A Rare Case Report

Crohn’s disease (CD) is a granulomatous inflammatory disease that can involve any part of the gastrointestinal tract, from mouth to anus. In most cases, it remits and relapses in the terminal ileum, requiring treatment via steroid boluses. In rare cases, however, CD can involve the pulmonary system presenting as dyspnea on exertion and dry cough. We present a case of a 38-year-old man who developed shortness of breath, cough, and wheezing for one month after a colectomy procedure due to recurrent toxic megacolon. He recovered and tolerated extubation successfully and was prescribed mesalamine as maintenance therapy for CD. His pulmonary symptoms after the colectomy, along with his imaging and pulmonary function tests, indicated pulmonary involvement in the lungs as a progression of the primary inflammatory bowel disease. After confirming this diagnosis, he was treated with oral high-dose steroids after successful diagnosis, and the patient’s symptoms improved dramatically. This case highlights often overlooked CD bronchopulmonary involvement in the postoperative period.

Interstitial Lung Disease in a 70-Year-Old Man with Ulcerative Colitis

Interstitial lung disease is a rare but increasingly recognized extraintestinal manifestation of inflammatory bowel disease that can have devastating consequences if left untreated. We report a case of ulcerative colitis–associated interstitial lung disease presenting with acute hypoxic respiratory failure during an ulcerative colitis flare. Gastroenterologists and pulmonologists should be aware of the numerous bronchopulmonary signs and symptoms that can suggest systemic illness in inflammatory bowel disease.

Gynostemma pentaphyllum saponins attenuate inflammation in vitro and in vivo by inhibition of NF-κB and STAT3 signaling

Recent advances in the development of anti-inflammatory agents have improved their therapeutic outcome in inflammatory bowel disease (IBD), however, the presence of side effects and limited effectiveness hinder their widespread use. Therefore, novel compounds with strong anti-inflammatory efficacy are still required. In this study, we investigated the anti-inflammatory effect and potential mechanisms of Gynostemma pentaphyllum (Thunb.) Makino saponins (GpS), a major component of the herbal medicine widely used in Asian countries. In in vitro studies, we demonstrated that GpS dose dependently suppressed activation of macrophages, one of the main effectors in IBD. GpS also suppressed cytokine production and the activation of NF-κB and STAT3 signaling in lipopolysaccharide-induced macrophages, without affecting their viability. Further in vivo studies demonstrated that GpS could ameliorate the weight loss, increased disease activity index, colon shortening and histological damage associated with dextran sulfate sodium (DSS)-induced colitis in mice. In agreement with results from our in vitro experiments, GpS suppressed cytokine production and activation of NF-κB and STAT3 signaling in the colons of DSS-induced mice.

In this study, we present for the first time, evidence of the therapeutic effect of GpS in IBD, highlighting its potential as an effective therapeutic against the disease.

Probiotic Lactobacillus Strains Stimulate the Inflammatory Response and Activate Human Macrophages

Lactobacilli have been shown to promote health functions. In this study, we analyzed the mechanism by which four different strains of probiotics affected innate immunity, such as regulation of ROS, cytokines, phagocytosis, bactericidal activity, signaling by NF-κB pp65, and TLR2 activation. The production of ROS was dependent on the concentration and species of Lactobacillus. The results obtained from the tested strains (Lactobacillus rhamnosus GG, L. rhamnosus KLSD, L. helveticus IMAU70129, and L. casei IMAU60214) showed that strains induced early proinflammatory cytokines such as IL-8,TNF-α, IL-12p70, and IL-6. However, IL-1β expression was induced only by L. helveticus and L. casei strains (after 24 h stimulation). Phagocytosis and bactericidal activity of macrophages against various pathogens, such as S. aureus, S. typhimurium, and E. coli, were increased by pretreatment with Lactobacillus. The nuclear translocation NF-κB pp65 and TLR2-dependent signaling were also increased by treatment with the probiotics. Taken together, the experiments demonstrate that probiotic strains of Lactobacillus exert early immunostimulatory effects that may be directly linked to the initial inflammation of the response of human macrophages.

Ulcerative colitis with acute pleurisy: A case report and review of the literature

RATIONALE

Inflammatory bowel diseases (IBD), including ulcerative colitis (UC) and Crohn's disease, are associated with a large number of extraintestinal manifestations. Pulmonary manifestations are infrequently seen in patients with IBD. Moreover, serositis including pleural and pericardial manifestations in UC is rare.

PATIENT CONCERNS

We report a case of UC with acute pleurisy in a 43-year-old man; review literature; and discuss the diagnosis, differential diagnosis, and treatment.

DIAGNOSES

Active duodenal ulcer was found using gastroscopy. Multiple ulcers in segmented pattern were noticed in the left hemi-colon using colonoscopy. An UC in active stage was confirmed subsequently by histology.

INTERVENTION

The patient was treated with bifidobacterium tetravaccine tablets, oral mesalazine and mesalazine enemas. The omeprazole and mucosal protective agents were given to treat the duodenal ulcer.

OUTCOMES

As follow-up, the therapy including oral mesalazine and infliximab regularly was continued and the patient condition was stabilized.

MAIN LESSON

Pulmonary involvement should be considered in patients who develop pleurisy in UC. Infliximab is considered the better available treatment for patients presenting with pleurisy in UC.

Predictors of vitamin D deficiency in inflammatory bowel disease and health: A Mississippi perspective

AIM

To identify the predictors of vitamin D deficiency in patients with and without inflammatory bowel disease (IBD).

METHODS

Patients with ulcerative colitis (UC) or Crohn's disease (CD) related diagnostic codes who received medical care at University of Mississippi Medical Center between July 2012 and 2015 were identified. After thorough chart review, we identified patients with biopsy proven IBD who had also been tested for serum 25-hydroxyvitamin D [25(OH)D] concentration. We compared these patients to a previously studied cohort of healthy controls who also had vitamin D concentration checked. Logistic regression analysis was performed to determine the association between vitamin d deficiency and UC, CD, race, age, gender and body mass index (BMI).

RESULTS

We identified 237 patients with confirmed IBD. Of these, only 211 had a serum 25(OH)D concentrations available in the medical record. The group of healthy controls consisted of 98 individuals with available serum 25(OH)D concentration. 43% of IBD patients were African American (AA). Patients with CD were more likely to have vitamin D concentration checked. Bivariate analysis showed that AA (51% vs 21%, P = 0.00001), subjects with BMI >30 kg/m2 (39% vs 23% P = 0.01) and CD (40% vs 26%, P = 0.04) were more likely to be vitamin D deficient than vitamin D sufficient. Those with Age > 65 were more likely to be vitamin D sufficient (46% vs 15%, P = 0.04). Multiple regression showed that only BMI > 30 kg/m2 and AA race are associated with vitamin D deficiency.

CONCLUSION

BMI > 30 kg/m2 and AA race are predictive of vitamin D deficiency. Gender, age and diagnosis of IBD are not predictive of vitamin D deficiency.

Probiotic Lactobacillus Strains Stimulate the Inflammatory Response and Activate Human Macrophages

Lactobacilli have been shown to promote health functions. In this study, we analyzed the mechanism by which four different strains of probiotics affected innate immunity, such as regulation of ROS, cytokines, phagocytosis, bactericidal activity, signaling by NF-κB pp65, and TLR2 activation. The production of ROS was dependent on the concentration and species of Lactobacillus. The results obtained from the tested strains (Lactobacillus rhamnosus GG, L. rhamnosus KLSD, L. helveticus IMAU70129, and L. casei IMAU60214) showed that strains induced early proinflammatory cytokines such as IL-8,TNF-α, IL-12p70, and IL-6. However, IL-1β expression was induced only by L. helveticus and L. casei strains (after 24 h stimulation). Phagocytosis and bactericidal activity of macrophages against various pathogens, such as S. aureus, S. typhimurium, and E. coli, were increased by pretreatment with Lactobacillus. The nuclear translocation NF-κB pp65 and TLR2-dependent signaling were also increased by treatment with the probiotics. Taken together, the experiments demonstrate that probiotic strains of Lactobacillus exert early immunostimulatory effects that may be directly linked to the initial inflammation of the response of human macrophages.

Development of an Antigen-driven Colitis Model to Study Presentation of Antigens by Antigen Presenting Cells to T Cells

Inflammatory bowel disease (IBD) is a chronic inflammation which affects the gastrointestinal tract (GIT). One of the best ways to study the immunological mechanisms involved during the disease is the T cell transfer model of colitis. In this model, immunodeficient mice (RAG(-/-) recipients) are reconstituted with naive CD4(+) T cells from healthy wild type hosts. This model allows examination of the earliest immunological events leading to disease and chronic inflammation, when the gut inflammation perpetuates but does not depend on a defined antigen. To study the potential role of antigen presenting cells (APCs) in the disease process, it is helpful to have an antigen-driven disease model, in which a defined commensal-derived antigen leads to colitis. An antigen driven-colitis model has hence been developed. In this model OT-II CD4(+) T cells, that can recognize only specific epitopes in the OVA protein, are transferred into RAG(-/-) hosts challenged with CFP-OVA-expressing E. coli. This model allows the examination of interactions between APCs and T cells in the lamina propria.

Effect of compound dracorhodin enema on pulmonary and colonic expression of interleukin-6 in mice with distal ulcerative colitis

AIM: To investigate the protective effect of compound dracorhodin enema on the lung and intestine of mice with distal ulcerative colitis (UC).

METHODS: Sixty male BALB/c mice were randomly divided into four groups (n = 15 each): a normal group, a dextran sulfate sodium (DSS) group, a compound dracorhodin enema group, and a DSS + compound dracorhodin enema group. After inducing UC, the normal group and DSS group were given 1 mL saline, and the other two groups were given compound dracorhodin enema [0.075 g/(kg•d), 1 mL] by gavage. After treatment, disease activity index (DAI) score, colonic histopathology score (HI), lung HI score, and hematoxylin-eosin (HE) staining were used to evaluate the severity of inflammation. Enzyme-linked immunosorbent assay (ELISA), immunohistochemistry, and real-time quantitative PCR (RT-QPCR) assay were used to detect the expression of interleukin (IL)-6 in the lung and colon.

RESULTS: Compared with the normal group and compound dracorhodin enema group, DAI score, colonic HI score, and lung HI score were significantly higher in the other two groups (P < 0.05). Compared with the DSS + compound dracorhodin enema group, colonic and pulmonary tissue inflammation was significantly more severe and pulmonary and colonic expression of IL-6 was significantly higher in the DSS group (P < 0.05).

CONCLUSION: Compound dracorhodin enema can decrease the expression of IL-6 and therefore alleviate UC and UC related lung injury in mice.

Pulmonary manifestations of inflammatory bowel disease

Extraintestinal manifestations of inflammatory bowel disease (IBD) are a systemic illness that may affect up to half of all patients. Among the extraintestinal manifestations of IBD, those involving the lungs are relatively rare and often overlooked. However, there is a wide array of such manifestations, spanning from airway disease to lung parenchymal disease, thromboembolic disease, pleural disease, enteric-pulmonary fistulas, pulmonary function test abnormalities, and adverse drug reactions. The spectrum of IBD manifestations in the chest is broad, and the manifestations may mimic other diseases. Although infrequent, physicians dealing with IBD must be aware of these conditions, which are sometimes life-threatening, to avoid further health impairment of the patients and to alleviate their symptoms by prompt recognition and treatment. Knowledge of these manifestations in conjunction with pertinent clinical data is essential for establishing the correct diagnosis and treatment. The treatment of IBD-related respiratory disorders depends on the specific pattern of involvement, and in most patients, steroids are required in the initial management. Corticosteroids, both systemic and aerosolized, are the mainstay therapeutic approach, while antibiotics must also be administered in the case of infectious and suppurative processes, whose sequelae sometimes require surgical intervention.

Granulocyte macrophage colony-stimulating factor and the intestinal innate immune cell homeostasis in Crohn's disease

Current literature consolidates the view of Crohn's disease (CD) as a form of immunodeficiency highlighting dysregulation of intestinal innate immunity in the pathogenesis of CD. Intestinal macrophages derived from blood monocytes play a key role in sustaining the innate immune homeostasis in the intestine, suggesting that the monocyte/macrophage compartment might be an attractive therapeutic target for the management of CD. Granulocyte macrophage colony-stimulating factor (GM-CSF) is a hematopoietic growth factor that also promotes myeloid cell activation, proliferation, and differentiation. GM-CSF has a protective effect in human CD and mouse models of colitis. However, the role of GM-CSF in immune and inflammatory reactions in the intestine is not well defined. Beneficial effects exerted by GM-CSF during intestinal inflammation could relate to modulation of the mucosal barrier function in the intestine, including epithelial cell proliferation, survival, restitution, and immunomodulatory actions. The aim of this review is to summarize potential mechanistic roles of GM-CSF in intestinal innate immune cell homeostasis and to highlight its central role in maintenance of the intestinal immune barrier in the context of immunodeficiency in CD.

Macrophage migration inhibitory factor polymorphism and the risk of ulcerative colitis and Crohn's disease in Asian and European populations: a meta-analysis

OBJECTIVE

To determine whether macrophage migration inhibitory factor (MIF) gene polymorphism is associated with the risk of inflammatory bowel disease (IBD).

DESIGN

System review and meta-analysis.

METHODS

MEDLINE, EMBASE, Web of Science databases, Cochrane Library and the Chinese Biomedical Literature database (CBM) were searched for the case-control trails for MIF and IBD. All the studies included in this manuscript met the inclusion and exclusion criteria. An OR analysis using a 95% CI was employed to assess the association of the MIF-173 G/C polymorphism with IBD susceptibility.

RESULTS

There was a significant association between the MIF-173 G/C gene polymorphism and IBD in the total population under the recessive model (CC vs GC+GG; OR=1.75, CI 1.04 to 2.95, p=0.04 for heterogeneity) and the codominant model (CC vs GG; OR=1.74, CI 1.02 to 2.97, p=0.04 for heterogeneity). In the stratified analysis by ethnicity, significantly increased risks were observed for Asians using the recessive (OR=1.75, CI 1.04 to 2.95, p=0.04 for heterogeneity) and codominant models (OR=1.74, CI 1.02 to 2.97, p=0.04 for heterogeneity). Within the subgroups of UC and CD, significant differences were observed regarding UC using the recessive (OR=1.60, CI 1.09 to 2.35, p=0.02 for heterogeneity) and codominant models (OR=1.64, CI 1.12 to 2.41, p=0.01 for heterogeneity). In the stratified analysis by ethnicity for UC, significant differences were observed regarding CC in Asians vs GC+GG (OR=1.73, CI 1.02 to 2.94, p=0.04 for heterogeneity).

CONCLUSIONS

The meta-analysis suggested that the MIF-173 G/C polymorphism contributed to the susceptibility of IBD. When considering the subgroups of ethnicity and UC and CD, the results suggested that the polymorphism is more significant for UC in Asians.

Murine neonates infected with Yersinia enterocolitica develop rapid and robust proinflammatory responses in intestinal lymphoid tissues

Neonatal animals are generally very susceptible to infection with bacterial pathogens. However, we recently reported that neonatal mice are highly resistant to orogastric infection with Yersinia enterocolitica. Here, we show that proinflammatory responses greatly exceeding those in adults arise very rapidly in the mesenteric lymph nodes (MLN) of neonates. High-level induction of proinflammatory gene expression occurred in the neonatal MLN as early as 18 h postinfection. Marked innate phagocyte recruitment was subsequently detected at 24 h postinfection. Enzyme-linked immunosorbent spot assay (ELISPOT) analyses indicated that enhanced inflammation in neonatal MLN is contributed to, in part, by an increased frequency of proinflammatory cytokine-secreting cells. Moreover, both CD11b(+) and CD11b(-) cell populations appeared to play a role in proinflammatory gene expression. The level of inflammation in neonatal MLN was also dependent on key bacterial components. Y. enterocolitica lacking the virulence plasmid failed to induce innate phagocyte recruitment. In contrast, tumor necrosis factor alpha (TNF-α) protein expression and neutrophil recruitment were strikingly higher in neonatal MLN after infection with a yopP-deficient strain than with wild-type Y. enterocolitica, whereas only modest increases occurred in adults. This hyperinflammatory response was associated with greater colonization of the spleen and higher mortality in neonates, while there was no difference in mortality among adults. This model highlights the dynamic levels of inflammation in the intestinal lymphoid tissues and reveals the protective (wild-type strain) versus harmful (yopP-deficient strain) consequences of inflammation in neonates. Moreover, these results reveal that the neonatal intestinal lymphoid tissues have great potential to rapidly mobilize innate components in response to infection with bacterial enteropathogens.

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.

Pulmonary manifestations in inflammatory bowel disease: a prospective study

BACKGROUND

Although pulmonary abnormalities have been recognized in patients with inflammatory bowel diseases (IBD), their prevalence and clinical significance are not known.

AIM

To study the prevalence and clinical significance of pulmonary abnormalities in patients with IBD.

METHODS

Ninety-five non-consecutive patients with IBD (12 Crohn's disease, 83 ulcerative colitis; mean age 41.9 [SD 13] years; 47 women) were prospectively studied from January 2007 to March 2010. Pulmonary function tests (PFT) and high-resolution CT (HRCT) chest were performed in them. PFT were compared to those in 270 healthy (control) subjects matched for age, sex and smoking status.

RESULTS

Twenty-seven (28.5%) patients and 11 (4%) control subjects had abnormal PFT (p < 0.0001). Small airway obstruction was seen in 18 patients, restrictive defect in six and mixed defect in three. Twenty-one (22%) patients had abnormal HRCT findings - bronchiectasis and nodules (nine patients each, including one with nodules who later developed active tuberculosis after infliximab therapy), parenchymal bands (8), mediastinal lymphadenopathy (five, including two with tuberculosis on histology and culture), emphysema (5), brochiolitis (2), pleural effusion or thickening (2), pericardial effusion (2), patchy consolidation (1), ground-glass opacities (1) and lung metastasis (1). Three patients had symptoms (one asthma, two cough).

CONCLUSION

PFT and HRCT chest showed abnormality in about one-quarter of patients with IBD. A majority of patients with these abnormalities were asymptomatic.

Protective effects of Kurozu and Kurozu Moromimatsu on dextran sulfate sodium-induced experimental colitis

BACKGROUND

Kurozu, a traditional Japanese black vinegar made from unpolished rice, and Kurozu Moromimatsu (Kurozu-M), its sediment, are both consumed in Japan as health foods or supplements. However, it is not known whether they have anti-colitis activity.

AIMS

We examined the protective effects of Kurozu and Kurozu-M in an animal model of dextran sulfate sodium (DSS)-induced colitis.

METHODS

DSS-induced colitis was induced in C57 black 6 mice by orally administering 3.5% DSS solution for 12 days. The control group received basal CE-2 diet (n = 10), the Kurozu group received CE-2 containing Kurozu (n = 10), the Kurozu-M group received CE-2 containing Kurozu-M (n = 10), and the acetic acid group received CE-2 containing acetic acid (n = 10), starting a week before DSS administration. Changes of body weight and bloody stool frequency were monitored. At 12 days after DSS administration, mice were killed for pathological examination and measurement of nitrotyrosine levels in rectal tissues.

RESULTS

Kurozu significantly inhibited body weight loss during 6-12 days after DSS administration and reduced bloody stool frequency during 2-12 days, and also significantly decreased nitrotyrosine levels at 12 days, compared to the control group. Kurozu-M significantly inhibited body weight loss during 6-8 days after DSS administration and reduced bloody stool frequency during 2-12 days, but tissue nitrotyrosine level was not significantly different from the control. Acetic acid had no ameliorating effect on DSS-induced colitis compared to the control group.

CONCLUSIONS

Kurozu and Kurozu-M have protective effects against DSS-induced colitis. Kurozu has anti-oxidative and anti-nitration activity.

Aberrant response to commensal Bacteroides thetaiotaomicron in Crohn's disease: an ex vivo human organ culture study

BACKGROUND

Human ex vivo evidence indicating that an inappropriate immune response(s) to nonpathogenic bacteria contributes to disease pathogenesis in pediatric Crohn's disease (CD) is limited. The aim of the present study was to compare and contrast the early innate immune response of pediatric "healthy" versus CD mucosa to pathogenic, probiotic, and commensal bacteria.

METHODS

"Healthy control" and CD pediatric mucosal biopsies (terminal ileum and transverse colon) were cocultured for 8 hours with E. coli O42, Lactobacillus GG (LGG), Bacteroidesthetaiotaomicron (B. theta), or stimulated with interleukin (IL)-1β (positive control). Matched nonstimulated biopsies served as experimental controls. IL-8 was the immune marker of choice. IL-8 mRNA and protein levels were quantified by quantitative polymerase chain reaction and sandwich enzyme-linked immunosorbent assay, respectively.

RESULTS

IL-8 secretion was observed when control, ileal biopsies were exposed to pathogenic O42 and probiotic LGG, with no response noted to commensal B. theta. In comparison, Crohn's ileal biopsies showed impaired ability to induce IL-8 in response to O42 and LGG. Control colonic tissue showed a limited response to O42 or B. theta and LGG significantly reduced IL-8 secretion. Unlike control tissue, however, Crohn's ileal and colonic tissue did respond to B. theta, with more enhanced expression in the colon.

CONCLUSIONS

We provide the first ex vivo data to support the notion that aberrant mucosal recognition of commensal bacteria may contribute to pediatric CD. While IL-8 responses to O42 and LGG varied with disease status and anatomical location, B. theta consistently induced significant IL-8 both in ileal and colonic CD tissue, which was not seen in control, healthy tissue.

Immune phenotype in children with therapy-naïve remitted and relapsed Crohn's disease

AIM

To characterize the prevalence of subpopulations of CD4+ cells along with that of major inhibitor or stimulator cell types in therapy-naïve childhood Crohn's disease (CD) and to test whether abnormalities of immune phenotype are normalized with the improvement of clinical signs and symptoms of disease.

METHODS

We enrolled 26 pediatric patients with CD. 14 therapy-naïve CD children; of those, 10 children remitted on conventional therapy and formed the remission group. We also tested another group of 12 children who relapsed with conventional therapy and were given infliximab; and 15 healthy children who served as controls. The prevalence of Th1 and Th2, naïve and memory, activated and regulatory T cells, along with the members of innate immunity such as natural killer (NK), NK-T, myeloid and plasmocytoid dendritic cells (DCs), monocytes and Toll-like receptor (TLR)-2 and TLR-4 expression were determined in peripheral blood samples.

RESULTS

Children with therapy-naïve CD and those in relapse showed a decrease in Th1 cell prevalence. Simultaneously, an increased prevalence of memory and activated lymphocytes along with that of DCs and monocytes was observed. In addition, the ratio of myeloid /plasmocytoid DCs and the prevalence of TLR-2 or TLR-4 positive DCs and monocytes were also higher in therapy-naïve CD than in controls. The majority of alterations diminished in remitted CD irrespective of whether remission was obtained by conventional or biological therapy.

CONCLUSION

The finding that immune phenotype is normalized in remission suggests a link between immune phenotype and disease activity in childhood CD. Our observations support the involvement of members of the adaptive and innate immune systems in childhood CD.

Toward cell therapy using placenta-derived cells: disease mechanisms, cell biology, preclinical studies, and regulatory aspects at the round table

Among the many cell types that may prove useful to regenerative medicine, mounting evidence suggests that human term placenta-derived cells will join the list of significant contributors. In making new cell therapy-based strategies a clinical reality, it is fundamental that no a priori claims are made regarding which cell source is preferable for a particular therapeutic application. Rather, ongoing comparisons of the potentiality and characteristics of cells from different sources should be made to promote constant improvement in cell therapies, and such comparisons will likely show that individually tailored cells can address disease-specific clinical needs. The principle underlying such an approach is resistance to the notion that comprehensive characterization of any cell type has been achieved, neither in terms of phenotype nor risks-to-benefits ratio. Tailoring cell therapy approaches to specific conditions also requires an understanding of basic disease mechanisms and close collaboration between translational researchers and clinicians, to identify current needs and shortcomings in existing treatments. To this end, the international workshop entitled "Placenta-derived stem cells for treatment of inflammatory diseases: moving toward clinical application" was held in Brescia, Italy, in March 2009, and aimed to harness an understanding of basic inflammatory mechanisms inherent in human diseases with updated findings regarding biological and therapeutic properties of human placenta-derived cells, with particular emphasis on their potential for treating inflammatory diseases. Finally, steps required to allow their future clinical application according to regulatory aspects including good manufacturing practice (GMP) were also considered. In September 2009, the International Placenta Stem Cell Society (IPLASS) was founded to help strengthen the research network in this field.

Mucosal immunology, eosinophilic esophagitis, and other intestinal inflammatory diseases

The gastrointestinal mucosa constitutes the largest host-environment interface of the body. It uses both innate and adaptive immune mechanisms to provide protection from the diverse onslaught of foods, microbes, and other ingested products. The innate immune system is genetically encoded and evolutionarily ancient, possesses no memory, and lacks diversity. In contrast, the adaptive immune system is quite diverse, develops memory, and undergoes expansion after stimulation. The gastrointestinal mucosa is charged with the difficult task of mounting protective responses against invading microorganisms while simultaneously maintaining an overall state of nonresponsiveness or tolerance to innocuous substances, such as commensal bacteria and food antigens. Perturbation or malfunction of these complex protective mechanisms results in diseases, such as inflammatory bowel diseases, celiac disease, or eosinophilic gastrointestinal diseases.