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S1: Analysis of p50 NF-κB ablation in myeloid cells (p50Fl/Fl; Lyz2Cre mice) and enterocytes (p50Fl/Fl; VillinCre mice). S2: Analysis of inflammatory gene expression at different phases of colitisassociated CRC (CAC) development. S3: Lack of p50 NF-κB exacerbates DSS-induced colitis. S4: Genetic ablation of p50 unleashes anti-tumor M1-polarized activation of TAMs. S5: Lack of p50 shapes gut associated immune populations in AOM/DSS treated. S6: Lack of p50 selectively impairs lamina propria monocytes/macrophages accumulation in steady state conditions. mice. S7: Wt and p50-/- mice show similar levels of proliferative colonic cancer cells. S8: Nuclear accumulation of p50 in TAM at the inner tumor tissue does not correlate with CRC patients' outcome.

Although tumor-associated macrophages (TAM) display a M2-skewed tumor-promoting phenotype in most cancers, in colorectal cancer, both TAM polarization and its impact remain controversial. We investigated the role of the M2-polarizing p50 NF-κB subunit in orchestrating TAM phenotype, tumor microenvironment composition, and colorectal cancer progression. We first demonstrated, by parallel studies in colitis-associated cancer (CAC) and in genetically driven ApcMin mouse models, that the p50-dependent inhibition of M1-polarized gut inflammation supported colorectal cancer development. In accordance with these studies, p50–/– mice displayed exacerbated CAC with fewer and smaller tumors, along with enhanced levels of M1/Th1 cytokines/chemokines, including IL12 and CXCL10, whose administration restrained CAC development in vivo. The inflammatory profile supporting tumor resistance in colons from p50–/– tumor bearers correlated inversely with TAM load and positively with both recruitment of NK, NKT, CD8+ T cells and number of apoptotic tumor cells. In agreement, myeloid-specific ablation of p50 promoted tumor resistance in mice, whereas in colorectal cancer patients, a high number of p50+ TAMs at the invasive margin was associated with decreased IL12A and TBX21 expression and worse postsurgical outcome. Our findings point to p50 involvement in colorectal cancer development, through its engagement in the protumor activation of macrophages, and identify a candidate for prognostic and target therapeutic intervention. Cancer Immunol Res; 6(5); 578–93. ©2018 AACR.

Systemic delivery of VEGFC induces lymphangiogenesis and TAM recruitment. Related to Figure 2

Supplementary Material and Methods

S5 T cell gating strategy. Related to Figure 3. S6 FACS gating strategy for TAM and tumoral LEC and RNA sequencing validation. Related to Figure 4

Colorectal cancer is a major cause of cancer-related death in Western countries and is associated with increased numbers of lymphatic vessels (LV) and tumor-associated macrophages (TAM). The VEGFC/VEGFR3 pathway is regarded as the principal inducer of lymphangiogenesis and it contributes to metastases; however, no data are available regarding its role during primary colorectal cancer development. We found that both VEGFC and VEGFR3 were upregulated in human nonmetastatic colorectal cancer, with VEGFR3 expressed on both LVs and TAMs. With the use of three different preclinical models of colorectal cancer, we also discovered that the VEGFC/VEGFR3 axis can shape both lymphatic endothelial cells and TAMs to synergistically inhibit antitumor immunity and promote primary colorectal cancer growth. Therefore, VEGFR3-directed therapy could be envisioned for the treatment of nonmetastatic colorectal cancer.Significance:The prolymphangiogenic factor VEGFC is abundant in colorectal cancer and activates VEGFR3 present on cancer-associated macrophages and lymphatic vessels; activation of VEGFR3 signaling fosters cancer immune escape, resulting in enhanced tumor growth.

S7 LEC immunosuppressive function. Related to Figure 5. S8Macrophage depletion strategy. Related to Figure 6

Background: Patients on immunosuppressive drugs have been excluded from COVID-19 vaccines trials, creating concerns regarding their efficacy. Aims: To explore the humoral response to COVID-19 vaccines in patients with inflammatory bowel disease (IBD) Methods: Effectiveness and Safety of COVID-19 Vaccine in Patients with Inflammatory Bowel Disease (IBD) Treated with Immunomodulatory or Biological Drugs (ESCAPE-IBD) is a prospective, multicentre study promoted by the Italian Group for the study of Inflammatory Bowel Disease. We present data on serological response eight weeks after the second dose of COVID-19 vaccination in IBD patients and healthy controls (HCs). Results: 1076 patients with IBD and 1126 HCs were analyzed. Seropositivity for anti-SARS-CoV-2 IgG was reported for most IBD patients, even if with a lesser rate compared with HCs (92.1% vs. 97.9%; p

IntroductionSeveral studies have shown that inflammatory bowel diseases (IBD) patients treated with thiopurines have an increased risk of developing skin cancer.Sources of dataThis review is based on recent published literature regarding the use of thiopurines in IBD and skin malignancies.Areas of agreementExposure to thiopurines is significantly associated with nonmelanoma skin cancer, but not with melanoma. Primary and secondary prevention including sun-protective measures and regular dermatologic screening are recommended in IBD patients, particularly in those exposed to thiopurines.Areas of controversyBoth when and how immunosuppressive therapy should be resumed in patients with a prior history of skin cancer still remain debatable topics.Growing pointsThe benefit–risk balance between thiopurine therapy and risk of skin cancer should be evaluated in the drug decision process.Areas timely for developing researchThe approval of new effective strategies requires the re-evaluation of the positioning of thiopurines within the therapeutic algorithm based on an increasingly individualized approach.

Crohn's disease (CD) and ulcerative colitis (UC) are immune-mediated disorders characterized by a chronic inflammation, with intermittent exacerbations of symptoms and inflammation. In both diseases, medical treatment has made revolutionary steps forward. Nevertheless, surgery is still required in many cases due to inefficacy of multiple medical therapies. It is not clear whether surgery rates in inflammatory bowel diseases (IBD) are currently decreasing despite all improvements.Multidisciplinary management is critical in surgical patients to improve long-term outcomes. Endoscopy plays a crucial role, both before and after surgery, in planning therapeutic strategies and stratifying risk of recurrence. Aim of this review is to provide a deeper insight into the central role of endoscopy in the postoperative management of IBD patients, focusing on recent research advances, future challenges and unresolved questions.Both UC and CD surgical patients need endoscopy to define the correct therapeutic choice, predict subsequent disease course and adopt the correct surveillance strategy. In the next future, newer endoscopic techniques could be systematically applied in IBD patients after surgery, to assess early postoperative inflammation, response to treatment, or, regarding UC, to provide enhanced pouch surveillance, allowing for early detection of inflammation and dysplasia.

Introduction: Ulcerative colitis (UC) is a chronic relapsing disorder of the colonic tract. Dysregulated innate and adaptive immune pathways contribute to intestinal inflammation in IBD, and cytokines, including IL-12 and IL-23, play a key role. The blockade of both IL-12 and IL-23 may have an impact on different pathways of inflammation and could be effective for the treatment of inflammatory bowel diseases.Ustekinumab is a fully human IgG1kappa monoclonal antibody which binds to the shared p40 protein subunit of IL-12 and -23. It is currently approved for several immune-mediated diseases such as moderate to severe plaque psoriasis, psoriatic arthritis, and Crohn's disease, and has shown promising results in UC.Areas covered: A review of the literature was performed to understand several aspects including the role of IL-12 and -23 in UC, the potential therapeutic role of ustekinumab in inflammatory bowel disease, and the positioning of ustekinumab in the therapeutic algorithm of UC, based on extrapolated data from available randomized clinical trials.Expert opinion: Ustekinumab is effective and safe in UC, and shows potential advantages compared to other drugs in moderate-to-severe UC.

Microsatellite instability (MSI) is the landmark feature of DNA mismatch repair deficiency, which can be found in 15–20% of all colorectal cancers (CRC). This specific set of tumors has been initially perceived as a niche for geneticists or gastroenterologists focused on inherited predispositions. However, over the years, MSI has established itself as a key biomarker for the diagnosis, then extending to forecasting the disease behavior and prognostication, including the prediction of responsiveness to immunotherapy and eventually to kinase inhibitors, and possibly even to specific biological drugs. Thanks to the contribution of the characterization of MSI tumors, researchers have first acknowledged that a strong lymphocytic reaction is associated with a good prognosis. This understanding supported the prognostic implications in terms of the low metastatic potential of MSI-CRC and has led to modifications in the indications for adjuvant treatment. Furthermore, with the emergence of immunotherapy, this strong biomarker of responsiveness has exemplified the capability of re-activating an effective immune control by removing the brakes of immune evasion. Lately, a subset of MSI-CRC emerged as the ideal target for kinase inhibitors. This therapeutic scenario implies a paradox in which appropriate treatments for advanced disease are effective in a set of tumors that seldom evolve towards metastases.

Background and aims The role of new psychological factors such as psychopathological patterns and defense mechanisms in the care of inflammatory bowel disease (IBD) has been poorly investigated. We aimed to assess the psychological characteristics and defense mechanisms of IBD patients. Methods This was a single-center, observational, cross-sectional study. Consecutive adult IBD patients were enrolled and stratified according to disease activity. Sociodemographic and clinical data were collected, and validated questionnaires (Symptom Checklist-90-R [SCL-90-R]) for psychological distress, Defense Mechanism Inventory (DMI) for psychological defense mechanisms, and Inflammatory Bowel Disease Questionnaire (IBDQ) for quality of life (QoL) were administered. Results Two hundred one patients were enrolled: 101 in remission and 100 with active disease. The mean score for IBDQ was below the cutoff level (156.8 ± 37.8), with a significantly greater impairment of QoL in subjects with flares (136.5 vs 177.5, P < 0.001). Lower scores were associated with female gender. No patients had psychological scores above the cutoff for normality. Statistically higher SCL-90-R scores were found in active patients for obsessive-compulsive disorder (P = 0.026), depression (P = 0.013), anxiety (P = 0.013), phobic anxiety (P = 0.002), psychoticism (P = 0.007), global severity index (GSI) (P = 0.005) and positive symptom total (PST) (P = 0.001). A significantly increased probability of higher global indexes was associated with Crohn’s disease and disease flares. None of the defensive Defense Mechanism Inventory (DMI) styles resulted above the cutoff in our cohort. Conclusions Further data are needed to demonstrate the potential key role of psychological intervention in the therapeutic strategies utilized for IBD patients, and the identification of specific psychological patterns based on the patients profile is necessary to optimize psychological intervention.

Background and Aims Peroral endoscopic myotomy (POEM) has been recommended for achalasia treatment. To prevent the potential of infective risk, antibiotic prophylaxis is usually administered, whereas the additional need of antibiotic therapy after POEM is uncertain. The primary endpoint was to determine whether prophylaxis versus prophylaxis plus short therapy was needed after POEM. Methods Consecutive patients scheduled for POEM were randomly assigned (1:1) to group A (prophylactic cefazolin 2 g IV) or group B (prophylaxis + cefazolin 2 g IV × 3 followed by oral amoxicillin/clavulanate 3 g/day). Infective risk was assessed by means of host response, namely body temperature and serum levels of white blood cells and C-reactive protein; immune response (the cytokines interleukin [IL]-6, IL-1β, and tumor necrosis factor-α and microbial translocation mediators lipopolysaccharide binding protein and soluble CD14); and blood cultures at time points before (t0) and after (t1, t2) POEM. Results After POEM, none of the 124 enrolled patients (54.6 ± 12.6 years old; 64 men) developed any fever (body temperature: t0, 36.56± .49°C; t1, 36.53± .52°C; t2, 36.48± .41°C), without any differences between groups at any time point. Regarding systemic inflammation, no difference was reported between groups in serum levels of C-reactive protein and white blood cells. Considering microbial translocation mediated response, lipopolysaccharide binding protein (group A: t0, 1539 ± 168.6 pg/mL; t1, 1321 ± 149.1 pg/mL; t2, 2492 ± 283.2 pg/mL; group B: t0, 1318 ± 115.9 pg/mL; t1, 1492 ± 163.8 pg/mL; t2, 2600 ± 328.2 pg/mL) and soluble CD14 (group A: t0, 2.16 ± .15 μg/mL; t1, 1.89 ± .15 μg/mL; t2, 2.2 ± .15 μg/mL; group B: t0, 2.1 ± .13 μg/mL; t1, 2 ± .13 μg/mL; t2, 2.5 ± .2 μg/mL) were similar between the 2 groups; the immune response cytokines IL-6, IL-1β, and tumor necrosis factor-α also were similar in the 2 groups. In relation to blood cultures, at t1 the group B bacteremia rate was 3.2% (2/62) and group A was 1.6% (1/62) with no difference (P = .6). All subsequent blood cultures were negative at t2. Conclusions According to our study, postprophylactic short-term antimicrobial therapy after POEM is not required because of a very low residual infective risk. (Clinical trial registration number: NCT03587337 .)

Inflammatory bowel diseases, Crohn’s disease and ulcerative colitis, are life-long disorders characterized by the chronic relapsing inflammation of the gastrointestinal tract with the intermittent need for escalation treatment and, eventually, even surgery. The total proctocolectomy with ileal pouch–anal anastomosis (IPAA) is the surgical intervention of choice in subjects affected by ulcerative colitis (UC). Although IPAA provides satisfactory functional outcomes, it can be susceptible to some complications, including pouchitis as the most common. Furthermore, 10–20% of the pouchitis may develop into chronic pouchitis. The etiology of pouchitis is mostly unclear. However, the efficacy of antibiotics in pouchitis suggests that the dysbiosis of the IPAA microbiota plays an important role in its pathogenesis. We aimed to review the role of the microbiota in the pathogenesis and as a target therapy in subjects who develop pouchitis after undergoing the surgical intervention of total proctocolectomy with IPAA reconstruction.

Inflammatory bowel diseases (IBD), including ulcerative colitis (UC) and Crohn’s disease (CD), are chronic inflammatory diseases of the gastrointestinal tract. In the last few years, the development of biological agents targeting cytokines and receptors involved in IBD pathogenesis has led to better outcomes and has improved the course of the disease. Despite their effectiveness, drugs such as tumor necrosis factor (TNF) inhibitors, anti-Interleukin-12/23 and anti-integrins, do not induce a response in about one-third of patients, and 40% of patients lose response over time. Therefore, more efficient therapies are required. Recent studies showed that TL1A (Tumor necrosis factor-like cytokine 1A) acts as a regulator of mucosal immunity and participates in immunological pathways involved in the IBD pathogenesis. In this review article, we analyze the role of TL1A as a new potential target therapy in IBD patients.

Although tumor-associated macrophages (TAM) display a M2-skewed tumor-promoting phenotype in most cancers, in colorectal cancer, both TAM polarization and its impact remain controversial. We investigated the role of the M2-polarizing p50 NF-κB subunit in orchestrating TAM phenotype, tumor microenvironment composition, and colorectal cancer progression. We first demonstrated, by parallel studies in colitis-associated cancer (CAC) and in genetically driven ApcMin mouse models, that the p50-dependent inhibition of M1-polarized gut inflammation supported colorectal cancer development. In accordance with these studies, p50–/– mice displayed exacerbated CAC with fewer and smaller tumors, along with enhanced levels of M1/Th1 cytokines/chemokines, including IL12 and CXCL10, whose administration restrained CAC development in vivo. The inflammatory profile supporting tumor resistance in colons from p50–/– tumor bearers correlated inversely with TAM load and positively with both recruitment of NK, NKT, CD8+ T cells and number of apoptotic tumor cells. In agreement, myeloid-specific ablation of p50 promoted tumor resistance in mice, whereas in colorectal cancer patients, a high number of p50+ TAMs at the invasive margin was associated with decreased IL12A and TBX21 expression and worse postsurgical outcome. Our findings point to p50 involvement in colorectal cancer development, through its engagement in the protumor activation of macrophages, and identify a candidate for prognostic and target therapeutic intervention. Cancer Immunol Res; 6(5); 578–93. ©2018 AACR.

Background Infliximab (IFX) biosimilars CT-P13 and SB2 have comparable efficacy, safety, and immunogenicity to the originator Remicade (RMC). However, concerns about cross-switching patients between the 3 brands were raised in the absence of cross reactivity data between them. We aimed to determine whether antibodies to infliximab (ATI) in inflammatory bowel disease (IBD) patients cross-react with RMC, CT-P13, and SB2. Methods Based on previous ATI status, samples from 34 patients participating in the BIOSIM01 study (13 RMC, 9 CT-P13, and 12 switchers) were selected. Patients were treated with either RMC only, or CT-P13 only, or with RMC switched to CT-P13. Additionally, 28 IFX-naive patients were assayed as controls. In total, 180 samples were analyzed. ATI trough levels were measured in parallel with 3 different bridging Enzyme Linked Immunosorbent Assays constructed using the 3 drugs. Spearman's coefficient and percentages of agreement were used to study the correlation between each assay. Results In total, 76 samples out of 152 IFX-treated patient samples were ATI-positive (30 RMC, 14 CT-P13, and 32 switchers). All resulted ATI-positive when either CT-P13 or SB2 bridging assays were used. The overall percentage of agreement was 100% when compared either with CT-P13 or SB2 assays. No significant differences were found among ATI levels and coefficients (Spearman's 0.98 to 1.0, P < 0.0001). Conclusions ATI of RMC-treated, CT-P13-treated or RMC to CT-P13 switched patients show full cross-reactivity with CT-P13 and SB2. Findings suggest that immunodominant epitopes in the reference and CT-P13 drugs are equally present in SB2. Data support full interchangeability between biosimilars in regard to immunogenicity.

Prolyl hydroxylase domain-containing proteins (PHDs) regulate the adaptation of cells to hypoxia. Pan-hydroxylase inhibition is protective in experimental colitis, in which PHD1 plays a prominent role. However, it is currently unknown how PHD1 targeting regulates this protection and which cell type(s) are involved. Here, we demonstrated that Phd1 deletion in endothelial and haematopoietic cells (Phd1f/f Tie2:cre) protected mice from dextran sulphate sodium (DSS)-induced colitis, with reduced epithelial erosions, immune cell infiltration, and colonic microvascular dysfunction, whereas the response of Phd2f/+ Tie2:cre and Phd3f/f Tie2:cre mice to DSS was similar to that of their littermate controls. Using bone marrow chimeras and cell-specific cre mice, we demonstrated that ablation of Phd1 in haematopoietic cells but not in endothelial cells was both necessary and sufficient to inhibit experimental colitis. This effect relied, at least in part, on skewing of Phd1-deficient bone marrow-derived macrophages towards an anti-inflammatory M2 phenotype. These cells showed an attenuated nuclear factor-κB-dependent response to lipopolysaccharide (LPS), which in turn diminished endothelial chemokine expression. In addition, Phd1 deficiency in dendritic cells significantly reduced interleukin-1β production in response to LPS. Taken together, our results further support the development of selective PHD1 inhibitors for ulcerative colitis, and identify haematopoietic cells as their primary target. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Background Intestinal epithelial cells (IECs) play a pivotal role in controlling immune responses by activation of suppressive CD8+ T regulatory cells (Treg). In Crohn’s disease (CD) this response is impaired due to a defect in CEACAM5 expression on IECs. We previously identified a small region in CEACAM5 able to restore the impaired suppressive activity of CD8+ Treg cells in CD. Here, we tested the functionality of this small peptide in CD patients and evaluated its conformational structure to understand its interaction with T cells. Methods Suppression assays were done to assess the ability of peripheral blood (PB) CD8+ T cells isolated from healthy individuals and CD patients and stimulated with the small CEACAM5 peptide to suppress proliferation of activated CD4+ T cells. To understand the role of the Asparagine (N)71 residue present in the CEACAM5 small peptide, which has previously been shown to be pivotal for CD8+ T cell binding to CEACAM5, we tested a library of overlapping peptides in the same region as the small CEACAM5 peptide. Cytokine assays were performed to characterise CEACAM5 peptide-activated CD8+ T cells. Results CEACAM5 small peptide activated PB CD8+ T cells from CD patients significantly suppressed CD4+ T-cell proliferation. A new small peptide from the overlapping peptide library containing N71 induced the strongest suppression of proliferation. Peripheral CD8+ T cells produced increased interleukin (IL)-10 upon stimulation with the CEACAM5 peptide. Conclusion Our study offers a new approach for modulating the inflammatory state in CD by enhancing the suppressive function of CD8+ T cells using a CEACAM5 small peptide.

Colorectal cancer (CRC) is one of the most malignant tumors worldwide. Stromal cells residing in the tumor microenvironment strongly contribute to cancer progression through their crosstalk with cancer cells and extracellular matrix. Here we provide the first evidence that CRC-associated lymphatic endothelium displays a distinct matrisome-associated transcriptomic signature, which distinguishes them from healthy intestinal lymphatics. We also demonstrate that CRC-associated human intestinal lymphatic endothelial cells regulate tumor cell growth via growth differentiation factor 11, a soluble matrisome component which in CRC patients was found to be associated with tumor progression. Our data provide new insights into lymphatic contribution to CRC growth, aside from their conventional role as conduits of metastasis.

Introduction: Biosimilars represent great potential in cost saving and re-investment opportunities in healthcare and allow patients greater access to effective mAbs. Infliximab biosimilars are succ...

The potential of endoscopic evaluation in the management of inflammatory bowel diseases (IBD) has undoubtedly grown over the last few years. When dealing with IBD patients, histological remission (HR) is now considered a desirable target along with symptomatic and endoscopic remission, due to its association with better long-term outcomes. Consequently, the ability of endoscopic techniques to reflect microscopic findings in vivo without having to collect biopsies has become of upmost importance. In this context, a more accurate evaluation of inflammatory disease activity and the detection of dysplasia represent two mainstay targets for IBD endoscopists. New diagnostic technologies have been developed, such as dye-less chromoendoscopy, endomicroscopy, and molecular imaging, but their real incorporation in daily practice is not yet well defined. Although dye-chromoendoscopy is still recommended as the gold standard approach in dysplasia surveillance, recent research questioned the superiority of this technique over new advanced dye-less modalities [narrow band imaging (NBI), Fuji intelligent color enhancement (FICE), i-scan, blue light imaging (BLI) and linked color imaging (LCI)]. The endoscopic armamentarium might also be enriched by new video capsule endoscopy for monitoring disease activity, and high expectations are placed on the application of artificial intelligence (AI) systems to reduce operator-subjectivity and inter-observer variability. The goal of this review is to provide an updated insight on contemporary knowledge regarding new endoscopic techniques and devices, with special focus on their role in the assessment of disease activity and colorectal cancer surveillance.

Adaptive immunity in intestinal inflammation may play a key role in the pathogenesis of Crohn's disease. In particular, interleukin (IL)-23 may be a key mediator in chronic intestinal inflammation by inducing the differentiation of naïve CD4 + T cells into Th17, with the production of several pro-inflammatory cytokines. Furthermore, IL-23 induces interferon-γ (IFN- γ) production from activated T cells, a critical cytokine in innate and adaptive immunity against infections. Areas covered: We aim to review the available data from literature regarding the role of IL-23, with a more specific focus on the recent progresses in the therapeutic modulation of this cytokine. Expert commentary: Increased knowledge regarding the role of IL-23 has allowed for the development of effective therapeutic progresses by blocking the IL-23 mediated pathways. Primary or secondary loss of response to anti-TNF therapies in Crohn's disease patients during the first year is widely described in literature: the development of new drugs, with alternative mechanisms of action, is thus a key point to consider for the optimal management of these subjects. Drugs blocking the IL-12/23 pathway showed a good efficacy and safety profile in immune-mediated diseases Further studies are necessary regarding the role of the single blockade of IL-23.

Introduction: Biological agents are effective in ulcerative colitis (UC). Currently, 3 anti-TNF agents (infliximab, adalimumab, and golimumab) and 1 anti-integrin agent (vedolizumab) are approved for the treatment of UC. The mechanism of action of biologic agents can also give rise to several side effects, some even serious. It remains uncertain to what extent biologic treatments may be associated with an increased rate of infections, malignancies and other adverse eventsAreas covered: Our aim is to review the relevant data available in the literature and briefly summarize the safety profile of biological therapy in UC. We performed a literature search using the OVID, MEDLINE, PUBMED and EMBASE databases. Also other relevant sources of safety data were also used.Expert opinion: All biological agents currently used in UC are relatively safe. Accurate prevention measures and screening prior to start such therapies, and regular surveillance programs are strongly recommend to minimize any risk of infections, malignancy and other adverse events related to the use of monoclonal antibodies in UC patients.

Background & Aims Alterations in signaling pathways that regulate resolution of inflammation (resolving pathways) contribute to pathogenesis of ulcerative colitis (UC). The resolution process is regulated by lipid mediators, such as those derived from the ω-3 docosahexaenoic acid (DHA), whose esterified form is transported by the major facilitator superfamily domain containing 2A (MFSD2A) through the endothelium of brain, retina, and placenta. We investigated if and how MFSD2A regulates lipid metabolism of gut endothelial cells to promote resolution of intestinal inflammation. Methods We performed lipidomic and functional analyses of MFSD2A in mucosal biopsies and primary human intestinal microvascular endothelial cells (HIMECs) isolated from surgical specimens from patients with active, resolving UC and healthy individuals without UC (controls). MFSD2A was knocked down in HIMECs with small hairpin RNAs or overexpressed from a lentiviral vector. Human circulating endothelial progenitor cells that overexpress MFSD2A were transferred to CD1 nude mice with dextran sodium sulfate–induced colitis, with or without oral administration of DHA. Results Colonic biopsies from patients with UC had reduced levels of inflammation-resolving DHA-derived epoxy metabolites compared to healthy colon tissues or tissues with resolution of inflammation. Production of these metabolites by HIMECs required MFSD2A, which is required for DHA retention and metabolism in the gut vasculature. In mice with colitis, transplanted endothelial progenitor cells that overexpressed MFSD2A not only localized to the inflamed mucosa but also restored the ability of the endothelium to resolve intestinal inflammation, compared with mice with colitis that did not receive MFSD2A-overexpressing endothelial progenitors. Conclusions Levels of DHA-derived epoxides are lower in colon tissues from patients with UC than healthy and resolving mucosa. Production of these metabolites by gut endothelium requires MFSD2A; endothelial progenitor cells that overexpress MFSD2A reduce colitis in mice. This pathway might be induced to resolve intestinal inflammation in patients with colitis.

International audience; Crohn’s disease (CD) and ulcerative colitis (UC) are chronic inflammatory bowel diseases (IBDs) of unknown etiology that are associated with an aberrant mucosal immune response. Neoangiogenesis and vascular injury are observed in IBD along with increased lymphangiogenesis. While the pathogenic role of angiogenesis in IBD is well characterized, it is not clear how or if increased lymphangiogenesis promotes disease. Here, we determined that enhancing lymphangiogenesis and lymphatic function reduces experimental IBD. Specifically, we demonstrated that adenoviral induction of prolymphangiogenic factor VEGF-C provides marked protection against the development of acute and chronic colitis in 2 different animal models. VEGF-C–dependent protection was observed in combination with increased inflammatory cell mobilization and bacterial antigen clearance from the inflamed colon to the draining lymph nodes. Moreover, we found that the VEGF-C/VEGFR3 pathway regulates macrophage (MΦ) plasticity and activation both in cultured MΦs and in vivo, imparting a hybrid M1-M2 phenotype. The protective function of VEGF-C was meditated by the so-called resolving MΦs during chronic experimental colitis in a STAT6-dependent manner. Together, these findings shed light on the contribution of lymphatics to the pathogenesis of gut inflammation and suggest that correction of defective lymphatic function with VEGF-C has potential as a therapeutic strategy for IBD.

The protein C (PC) pathway is a well-characterized coagulation system. Endothelial PC receptors and thrombomodulin mediate the conversion of PC to its activated form, a potent anticoagulant and anti-inflammatory molecule. Here we show that the PC pathway is expressed on intestinal epithelial cells. The epithelial expression of PC and endothelial PC receptor is down-regulated In patients with inflammatory bowel disease. PC −/− /PC(Tg) mice, expressing only 3% of WT PC, developed spontaneous intestinal inflammation and were prone to severe experimental colitis. These mice also demonstrated spontaneous elevated production of inflammatory cytokines and increased intestinal permeability. Structural analysis of epithelial tight junction molecules revealed that lack of PC leads to decreased JAM-A and claudin-3 expression and an altered pattern of ZO-1 expression. In vitro, treatment of epithelial cells with activated PC led to protection of tight junction disruption induced by TNF-α, and in vivo, topical treatment with activated PC led to mucosal healing and amelioration of colitis. Taken together, these findings demonstrate that the PC pathway is a unique system involved in controlling intestinal homeostasis and inflammation by regulating epithelial barrier function.

Deficiency in 1 alpha,25-dihydroxyvitamin D(3) (1,25D(3)) has been suggested as an important environmental factor for immuno-mediated disorders including inflammatory bowel diseases (IBD), comprising Crohn's disease and ulcerative colitis, both characterized by chronic intestinal inflammation. Administration of vitamin D receptor (VDR) agonists can ameliorate spontaneous and induced animal models of colitis, but hypercalcemia is a dose-limiting adverse event. Previous work in our laboratory has identified 1 alpha,25(OH)(2)-16-ene-20-cyclopropyl-vitamin D(3) (BXL-62) as a potent anti-inflammatory VDR agonist with a low calcemic activity. In the present study, we confirm the marked anti-inflammatory properties of BXL-62 and show its capacity to induce VDR primary response genes, like CYP24A1 and CAMP, at lower concentrations than 1,25D(3), in PBMCs from IBD patients. Its higher anti-inflammatory potency compared to 1,25D(3) was demonstrated by the significantly more potent inhibition in PBMCs and in lymphocyte-enriched lamina propria mononuclear cells of the pro-inflammatory cytokines TNF-alpha, IL-12/23p40, IL-6 and IFN-gamma, both at mRNA and protein level. The therapeutic efficacy of intra-rectal administration of BXL-62 in experimental IBD is shown by its beneficial effects, significantly higher than 1,25D(3), to induce recovery of clinical symptoms of colitis at normocalcemic doses in mice undergoing dextran sodium sulfate-induced colitis. These results confirm the therapeutic efficacy of VDR agonists in experimental colitis, and suggest BXL-62 as a promising compound for IBD treatment. (C) 2010 Elsevier B.V. All rights reserved.

Although angiogenesis is viewed as a fundamental component of inflammatory bowel disease (IBD) pathogenesis, we presently lack a thorough knowledge of the cell type(s) involved in its induction and maintenance in the inflamed intestinal mucosa. This study aimed to determine whether platelet (PLT) adhesion to inflamed intestinal endothelial cells of human origin may favour angiogenesis. Unstimulated or thrombin-activated human PLT were overlaid on resting or tumour necrosis factor (TNF)-α-treated human intestinal microvascular endothelial cells (HIMEC), in the presence or absence of blocking antibodies to either vascular cell adhesion molecule (VCAM)-1, intercellular adhesion molecule (ICAM)-1, integrin α(v) β(3) , tissue factor (TF) or fractalkine (FKN). PLT adhesion to HIMEC was evaluated by fluorescence microscopy, and release of angiogenic factors (VEGF and soluble CD40L) was measured by ELISA. A matrigel tubule formation assay was used to estimate PLT capacity to induce angiogenesis after co-culturing with HIMEC. TNF-α up-regulated ICAM-1, α(v) β(3) and FKN expression on HIMEC. When thrombin-activated PLT were co-cultured with unstimulated HIMEC, PLT adhesion increased significantly, and this response was further enhanced by HIMEC activation with TNF-α. PLT adhesion to HIMEC was VCAM-1 and TF independent but ICAM-1, FKN and integrin α(v) β(3) dependent. VEGF and sCD40L were undetectable in HIMEC cultures either before or after TNF-α stimulation. By contrast, VEGF and sCD40L release significantly increased when resting or activated PLT were co-cultured with TNF-α-pre-treated HIMEC. These effects were much more pronounced when PLT were derived from IBD patients. Importantly, thrombin-activated PLT promoted tubule formation in HIMEC, a functional estimate of their angiogenic potential. In conclusion, PLT adhesion to TNF-α-pre-treated HIMEC is mediated by ICAM-1, FKN and α(v) β(3) , and is associated with VEGF and sCD40L release. These findings suggest that inflamed HIMEC may recruit PLT which, upon release of pro-angiogenic factors, actively contribute to inflammation-induced angiogenesis.

Crohn's disease (CD) is a chronic panenteric disease of unknown aethiology tending to progress, inspite medical or surgical treatment. Intestinal fibrosis is among the most common complications of CD, resulting in stricture formation in the small intestine and colon. About 75% of CD patients will undergo surgery at least once over the course of their disease and fibrotic strictures represents the main indication for surgery and the first cause of hospitalization and costs for CD patients. Clinical management of intestinal strictures depends on the type of stricture: inflammatory strictures are treated medically and are usually responsive to treatment, while fibrotic strictures require surgery. Clinical decisions regarding the right treatment choice for such conditions require proper knowledge on what to expect from the emerging drug strategies and surgical techniques. To achieve optimal results in patients management an approach combining the expertise of both gastroenterologist and colorectal surgeon is essential. This review aims at providing clinicians with an overview on fibrotic strictures in CD patients particular focus will be placed on the principal imaging modalities, and the medical, endoscopic and surgical treatment options with relative indications, according to the most recent evidence available.

White adipose tissue (WAT) is an important endocrine organ that secretes approximately 30 biologically active peptides and proteins, collectively termed "adipokines". These are either produced exclusively by WAT (mainly adiponectin, leptin and resistin) or also by other tissues [e.g. tumour necrosis factor (TNF)-alpha, interleukin (IL)-6, plasminogen activator inhibitor (PAI)-1, angiotensinogen]. Adipokines play a central role in body homeostasis including the regulation of food intake and energy balance, insulin action, lipid and glucose metabolism, angiogenesis and vascular remodelling, regulation of blood pressure and coagulation. Excess WAT, especially visceral obesity, is linked to obesity-related health problems through insulin resistance (IR) [leading to type 2 diabetes mellitus (T2DM)] and systemic low-grade inflammation [leading to cardiovascular disease (CVD)]. The adipokines are important mediators of these adverse effects. This review describes the role of proinflammatory adipokines in the pathogenesis of IR and of the chronic inflammatory state associated with visceral obesity. Moreover, it summarises treatment options for the normalisation of adipokine levels, which might confer an additional clinical benefit in the effort to prevent or treat obesity-related T2DM and CVD.

The Triggering Receptors Expressed on Myeloid cells (TREM) are a family of cell-surface molecules that control inflammation, bone homeostasis, neurological development and blood coagulation. TREM-1 and TREM-2, the best-characterized receptors so far, play divergent roles in several infectious diseases. In the intestine, TREM-1 is highly expressed by macrophages, contributing to inflammatory bowel disease (IBD) pathogenesis. Contrary to current understanding, TREM-2 also promotes inflammation in IBD by fueling dendritic cell functions. This review will focus specifically on recent insights into the role of TREM proteins in IBD development, and discuss opportunities for novel treatment approaches.

Summary The altered expression of micro-RNA (miRNA) has been associated with Crohn's disease (CD) and ulcerative colitis (UC). The aim of this study was to establish specific miRNA expression patterns in the serum and mucosa of inflammatory bowel disease (IBD) patients (UC and CD with colonic involvement) at different stages of the disease. Serum and biopsies from nine active CD (aCD), nine inactive CD (iCD), nine active UC (aUC) and nine inactive UC (iUC) and serum from 33 healthy subjects were collected. Up to 700 miRNAs were evaluated by the TaqMan® human miRNA array. The ΔCt values were obtained using the mean expression values of all expressed miRNAs in a given sample as a normalization factor for miRNA real-time quantitative polymerase chain reaction data. The levels of serum miRNAs in CD and UC patients were different to healthy subjects. Thirteen serum miRNAs were expressed commonly in CD and UC patients. Two miRNAs were higher and four miRNAs were lower in the serum of aCD than iCD. No serum miRNA was regulated exclusively in aUC compared with iUC patients. Four miRNAs were higher and three miRNAs were lower in the mucosa of aCD than iCD. Two miRNAs were higher and three miRNAs were lower in the mucosa of aUC than iUC. No serum miRNAs coincided with tissue miRNAs in aCD and aUC patients. Our results suggest the existence of specific miRNA expression patterns associated with IBD and their different stages and support the utility of miRNA as possible biomarkers. This pilot study needs to be validated in a large prospective cohort.

BACKGROUND AND AIMS: Triggering receptor expressed on myeloid cells (TREM)-2 is a surface receptor detected on macrophages, dendritic cells, and microglia that binds repeated anionic motifs on yeast and Gram-positive and Gram-negative bacteria. Little is known about TREM-2 expression and function in the intestine or its role in inflammatory bowel disease (IBD). We investigated the expression of TREM-2 in the intestinal lamina propria and its role in the development of colonic inflammation. METHODS: We measured levels of TREM-2 in lamina propria mononuclear cells from surgical specimens collected from patients with IBD or cancer (controls). We analyzed the development of colitis in TREM-2 knockout and wild-type mice. Colon samples were isolated from mice and analyzed for cytokine expression, phagocytosis of bacteria, proliferation in colonic crypts, lamina propria mononuclear cell function, and T-cell activation by ovalbumin. RESULTS: TREM-2 was virtually absent from colon samples of control patients, but levels were significantly higher in within the inflamed mucosa of patients with IBD; it was mainly expressed by CD11c+ cells. Levels of TREM-2 increased as acute or chronic colitis was induced in mice. TREM-2 knockout mice developed less severe colitis than wild-type mice; the knockout mice lost less body weight, had a lower disease activity index, and had smaller mucosal lesions in endoscopic analysis. Colon dendritic cells from TREM-2 knockout mice produced lower levels of inflammatory cytokines and had reduced levels of bacterial killing and T-cell activation than cells from wild-type mice. CONCLUSIONS: TREM-2 contributes to mucosal inflammation during development of colitis in mice. Levels of TREM-2 are increased within the inflamed mucosa of patients with IBD, indicating its potential as a therapeutic target. © 2013 by the AGA Institute.