Strategy For Inflammatory Bowel Disease Research Articles

Inhibition of proprotein convertase subtilisin/kexin type 9 attenuates 2,4,6-trinitrobenzenesulfonic acid-induced colitis via repressing toll-like receptor 4/nuclear factor-kappa B.

Inflammatory bowel disease (IBD) is characterized by recurring inflammatory disorders in digestive system, and devoid of effective treatment. Proprotein convertase subtilisin/kexin type 9 (PCSK9), stimulated via inflammation whose inhibition could decrease secretion of inflammatory factors. We then determined whether inhibition of PCSK9 could improve the inflammation. First, rats model of colitis was first established via administration of 2,4,6-trinitrobenzenesulfonic acid (TNBS), and then verified via determination of body weight loss, myeloperoxidase (MPO) activity, and histopathological analysis of colonic damage. Results showed that treatment with TNBS induced a great body weight loss, MPO activity increase, and serious colonic damage, showing an obviously character of IBD. PCSK9 was elevated in TNBS-induced rats, and PCSK9 inhibition delivered by adenovirus vector increased the body weight, decreased MPO activity, and ameliorated histological change of colon. Second, the protective effect of PCSK9 inhibition against TNBS-induced colitis was accompanied by decrease of proinflammatory factors secretion, including tumor necrosis factor-α, interleukin-1β, interleukin-6, intercellular adhesion molecule 1, and monocyte chemoattractant protein-1. TNBS could activate toll-like receptor 4 (TLR4)/nuclear factor-kappa B (NF-κB) signaling pathway, while PCSK9 inhibition suppressed activation of TLR4/NF-κB in TNBS-induced rats. In conclusion, PCSK9 inhibition attenuated TNBS-induced rat colitis through anti-inflammatory effect under inactivation of TLR4/NF-κB, suggesting potential therapeutic strategy in IBD.

Harnessing The Biology of Intestinal Organoids To Accelerate Drug Discovery in Inflammatory Bowel Disease: A One Health Approach

Rationale and SignificanceCanine inflammatory bowel disease (IBD) refers to a group of chronic gastrointestinal (GI) disorders of unknown cause and pathogenesis which mimic the spectrum of chronic enteropathies in human patients with IBD. There is currently no cure for IBD and many therapeutic interventions developed over the past 3 decades have consistently failed to demonstrate evidence of efficacy in clinical trials. There is, therefore, a critical need to develop robust drug screening tools to accelerate the availability of effective and safe therapeutic strategies for management of IBD. With the aim of modeling spontaneous GI disease in dogs and humans, intestinal stem cell (ISC)‐derived organoids are emerging as a promising ex vivo tool in the study of IBD pathogenesis. Our working testable hypothesis is that canine organoids will faithfully reproduce structural and functional changes of the intestinal epithelium in dogs with IBD, which will enable more accurate prediction of therapeutic drug efficacy and safety. Long‐term, this model will provide critical information for the design of canine clinical trials, and ultimately generate preclinical data for similar studies in humans with IBD. Altogether, we therefore expect to contribute to decreased morbidity/mortality, and improved quality of life in dogs and patients with IBD.MethodsISCs isolated from endoscopic biopsies of two healthy dogs and two dogs with active IBD were differentiated into intestinal organoids. Ileal organoids and matching tissues were probed by RNA in situ hybridization and immunohistochemistry for phenotypic changes in IBD. A panel of six phenotypic markers identified different epithelial cell lineages (LGR5+: intestinal stem cell, ALP: enterocyte, PAS: goblet cell, NeuroG3: enteroendocrine cell), epithelial barrier integrity (ZO‐1) and cell proliferation (Ki‐67). Functional features of IBD organoids were investigated by cystic fibrosis transmembrane conductance regulator (CFTR) organoid swelling assay to measure Cl− channel‐water conductance.ResultsOur preliminary findings suggest that IBD organoids exhibit increased cell proliferation, intestinal stem cells, enteroendocrine cells, and expression of tight junction protein as compared to healthy organoids. Similar trends were observed when comparing phenotypic marker expression in original intestinal tissues. Forskolin significantly (P < 0.05) increased swelling of IBD organoids after 1 and 4 hr vs. controls indicating functional CFTR in organoids.ConclusionOverall, our data show that ileal organoids derived from dogs with IBD recapitulate both the phenotypic and physiological features of diseased tissue compared to healthy tissue, demonstrating its utility as an ex vivo model for investigating mechanism and therapeutic strategies in IBD. These preliminary results will be further validated by additional intestinal biopsies from 14 dogs with IBD in an ongoing clinical trials.Support or Funding Information Research Support: IG BiosciencesPreliminary phenotypic characterization of IBD organoids.(Left) Representative RNA ISH of ALP and NeuroG3 staining in ileal organoids at x40 magnification (ratio of total area). Scale bar: 50 μm. (Right) Summary box plots of ALP and PAS expression in IBD vs. Control (CTR) organoids. Data from 10 distinct microscopic fields were aggregated per dog.Figure 1

Predictors of Infliximab Trough Concentrations in Inflammatory Bowel Disease Patients Using a Repeated-Measures Design.

Treating patients based on a treat-to-trough approach has been shown to be a cost-effective strategy for inflammatory bowel disease (IBD) patients who have become unresponsive to infliximab (IFX). However, the documented evidence for this is limited, and some controversy remains regarding the use of routine proactive therapeutic drug monitoring (TDM). To support routine TDM of IFX and regimen optimization in IBD patients, more in-depth knowledge of the covariates that affect the pharmacokinetic (PK) variability of IFX is needed. The aim of this study was to identify the characteristics of the patient, disease, and treatments that influence IFX PK and exposure in our cohort of IBD patients using a repeated-measures design. We performed a prospective observational study of adult IBD patients who received IFX between July 2013 and March 2017. We obtained repeated IFX trough concentration (Cmin) measurements and implemented a previously described population pharmacokinetic model to estimate individual clearance (CL). From the individual primary parameters, the area under the curve (AUC), half-life (t1/2), and central elimination rate constant (K10) were estimated. We performed a repeated-measures analysis to evaluate whether patient characteristics, disease status, concomitant immunosuppressive therapy, and immunogenicity are associated with IFX Cmin and PK parameters. We collected 429 Cmin measurements from 112 patients. The median of the Cmin values was 3.62 mg/L (1.47-6.02). Antibodies to IFX (ATI) were detected in 14 patients. The predicted median AUC was 28,421 mg/h/L (22,336-36,903). The median individual predicted CL, K10, and t1/2 values were 4.77 mL/kg/day (3.88-5.90), 0.09 days (0.08-0.12), and 12.22 days (9.49-14.87), respectively. IFX Cmin, AUC, CL, and K10 were significantly influenced by ATI and serum albumin concentrations. Moreover, body weight was significantly associated with AUC, CL, and K10. Patients receiving concurrent immunosuppressive therapy had higher Cmin and AUC values and lower CL and K10 values than those treated with IFX monotherapy. We also observed high intrapatient variability in Cmin values during the study period. In this repeated-measures study in a population of IBD patients, we observed significant associations between ATI, serum albumin concentration, concomitant immunosuppressive therapy, body weight and gender, and IFX Cmin, and CL. The high PK variability observed in this study supports the need for proactive TDM to optimize the use of IFX as early as possible in IBD patients.

P676 Faecal monitoring is useful in monitoring treatment response in anti-TNF-treated patients

Abstract Background Faecal drug concentration is not routinely measured as per therapeutic drug monitoring strategies in inflammatory bowel disease (IBD) patients receiving anti-TNF therapy. However, our previous research work suggested the importance of faecal drug monitoring of anti-TNF agents since active disease may be present in spite of normal serum anti-TNF levels. The aim of the present study was to examine the correlation between faecal calprotectin and faecal infliximab (IFX) concentration and to evaluate the cut-off value of faecal drug concentration in the respect of faecal calprotectin in patients treated with maintenance IFX therapy. Methods Consecutive patients with IBD receiving maintenance IFX therapy at 1st Department of Medicine, University of Szeged were enrolled in the present study. Faecal samples were obtained before the subsequent IFX infusion. Faecal calprotectin and IFX concentrations were determined with ELISA. The correlation between faecal calprotectin and faecal IFX concentration was statistically assessed. Results Sixty-seven IBD patients were enrolled. Female/male ratio was 49%–51%. Sixty-five point six% of the patients were diagnosed with Crohn’s disease and 34.3% with ulcerative colitis. Mean disease duration was 14.9 years (SD 9.7) at the time of analysis. Mean duration of IFX therapy was 42.3 month (SD 31.6). Twenty-eight point three% of the patients received escalated IFX therapy. Mean faecal calprotectin concentration was 545.7 µg/g (SD 379.4 µg/g). Mean faecal IFX concentration was 1 ng/ml (SD 1.3). Faecal calprotectin and faecal IFX concentration showed significant correlation (r=0.37, p = 0.002). A cut-off value of faecal IFX level of 0.6 ng/ml was determined at faecal calprotectin concentration of 500 µg/g. Conclusion According to our results IFX is detectable in the faeces at a calprotectin concentration of 500 µg/g. The cut-off value for faecal IFX concentration proved to be 0.6 ng/ml. Simultaneous determination of faecal anti-TNF and faecal calprotectin concentration is supposed to have a higher benefit in the evaluation of response to IFX therapy.

Interleukin-38 is elevated in inflammatory bowel diseases and suppresses intestinal inflammation

There has been no report investigating the role of IL-38 in inflammatory bowel diseases (IBD). Therefore, we investigated the expression of IL-38 in IBD patients and its role in regulating intestinal inflammation. The levels of IL-38 were significantly elevated in the intestine of IBD patients and DSS-induced colitis mice. Immunofluorescence analysis revealed that B cell, not macrophage or T cell, was the source of IL-38 in the intestine. We found that rIL-38 treatment significantly attenuated DSS-induced colitis, including alleviation of weight loss, disease activity index, macroscopic changes and histological damage of colon, along with lower levels of IL-1β and TNF-α. In vitro, rIL-38 significantly decreased the expression of proinflammatory cytokines in LPS-stimulated RAW 264.7 cells and BMDM. This is the first study suggesting that IL-38 may have a protective effect in IBD, which inhibits the production of proinflammatory cytokines from macrophages. IL-38 may represent a promising therapeutic strategy in IBD.

Prevalence of cervical HPV and attitude towards cervical screening in IBD patients under immunomodulatory treatment: a multidisciplinary management experience.

Therapeutic strategies for Inflammatory Bowel Diseases (IBD: Crohn's disease and Ulcerative Colitis) have improved but the risk for HPV infection in patients under immunomodulatory/biologic treatment is unclear. Objective of the study is to identify the attitude of patients and caregivers to cervical screening. To determine the prevalence of HPV and cervical lesions in IBD patients receiving immunomodulatory/biological treatment. IBD patients treated with immunomodulators were enrolled from November 2016 to September 2017, thanks to a multidisciplinary cooperation. A survey was administered to enrolled patients as well as to a selected network of IBD expert physicians. Patients who consented underwent gynecological examination, smear, HPV DNA test, colposcopy, vaginal and cervical microbiological swabs. 294 patients from AMICI Onlus Association, 119 patients from the hospital clinic, 30 doctors from national IBD centers participated to the survey. 19 patients from the IBD clinic underwent cervical screening. More than 90% of doctors consider their patients at risk of cervical cancer. A low prevalence of high-risk genotypes and related HPV lesions and an increased prevalence of bacterial vaginosis emerged in the studied population. Biological drugs could lead to a positive immunomodulation towards HPV infection. In IBD patients an alteration of the vaginal and intestinal microbiota seems to be coexisting.

Glutamine as A Therapeutic Strategy in Inflammatory Bowel Diseases: A Systematic Review

Glutamine as A Therapeutic Strategy in Inflammatory Bowel Diseases: A Systematic Review

Maggot Extracts Alleviate Inflammation and Oxidative Stress in Acute Experimental Colitis via the Activation of Nrf2.

Ulcerative colitis (UC) is a common chronic remitting disease driven through altered immune responses with production of inflammatory cytokines. Oxidant/antioxidant balance is also suggested to be an important factor for the recurrence and progression of UC. Maggots are known as a traditional Chinese medicine also known as “wu gu chong.” NF-E2-related factor-2 (Nrf2) transcription factor regulates the oxidative stress response and also represses inflammation. The aim of this study was to investigate the effects of maggot extracts on the amelioration of inflammation and oxidative stress in a mouse model of dextran sulfate sodium- (DSS-) induced colitis and evaluate if the maggot extracts could repress inflammation and oxidative stress using RAW 264.7 macrophages stimulated by lipopolysaccharide (LPS). In the present study, we found that the maggot extracts significantly prevented the loss of body weight and shortening of colon length in UC induced by DSS. Furthermore, DSS-induced expression of proinflammatory cytokines at both mRNA and protein levels in the colon was also attenuated by the maggot extracts. In addition, the maggot extracts could significantly suppress the expression of interleukin- (IL-) 1β, IL-6, TNF-α, NFκB p65, p-IκB, p22-phox, and gp91-phox in LPS-stimulated RAW 264.7 cells and colonic tissues. The maggot extracts increased the level of Nrf2 and prevented the degradation of Nrf2 through downregulating the expression of Keap1, which resulted in augmented levels of HO-1, SOD, and GSH-Px and reduced levels of MPO and MDA. However, after administering an Nrf2 inhibitor (ML385) to block the Nrf2/HO-1 pathway, we failed to observe the protective effects of the maggot extracts in mice with colitis and RAW 264.7 cells. Taken together, our data for the first time confirmed that the maggot extracts ameliorated inflammation and oxidative stress in experimental colitis via modulation of the Nrf2/HO-1 pathway. This study sheds light on the possible development of an effective therapeutic strategy for inflammatory bowel diseases.

Disease monitoring strategies in inflammatory bowel diseases: What do we mean by "tight control"?

In recent years, there has been a critical change in treatment paradigms in inflammatory bowel diseases (IBD) triggered by the arrival of new effective treatments aiming to prevent disease progression, bowel damage and disability. The insufficiency of symptomatic disease control and the well-known discordance between symptoms and objective measures of disease activity lead to the need of reviewing conventional treatment algorithms and developing new concepts of optimal therapeutic strategy. The treat-to-target strategies, defined by the selecting therapeutic targets in inflammatory bowel disease consensus recommendation, move away from only symptomatic disease control and support targeting composite therapeutic endpoints (clinical and endoscopical remission) and timely assessment. Emerging data suggest that early therapy using a treat-to-target approach and an algorithmic therapy escalation using regular disease monitoring by clinical and biochemical markers (fecal calprotectin and C-reactive protein) leads to improved outcomes. This review aims to present the emerging strategies and supporting evidence in the current therapeutic paradigm of IBD including the concepts of “early intervention”, “treat-to-target” and “tight control” strategies. We also discuss the real-word experience and applicability of these new strategies and give an overview on the future perspectives and areas in need of further research and potential improvement regarding treatment targets and (“tight”) disease monitoring strategies.

Extracellular Vesicles: A New Nano Tool for the Treatment of Inflammatory Bowel Diseases

The intestinal tract is a complex and important physiological and immunological organ. Intestinal tract homeostasis requires a series of coordinated interactions involving gut microbiota, the crypt intestinal stem cells (ISC) and the surrounding niche, including the intestinal epithelial cells, endothelial cells, dendritic cells, and macrophages. The destruction of intestinal homeostasis leads to autoimmune diseases, such as inflammatory bowel disease (IBD). IBD is a non-specific, and remittent- relapsing inflammatory disorder of the gastrointestinal tract. There is no effective method to keep patients in remission for a long term. It has been reported that extracellular vesicles (EVs) exert immune activation and immunosuppressive effects in the pathogenesis of IBD. In order to explore new therapeutic strategies for IBD, in this review, we summarize the observations on the immune properties and functions of EVs in intestinal mucosal immunity.

Tofacitinib Reprograms Human Monocytes of IBD Patients and Healthy Controls Toward a More Regulatory Phenotype.

The inhibition of Janus kinases (JAKs) and subsequent signal transducers and activators of transcription (STATs) by tofacitinib represents a new therapeutic strategy in inflammatory bowel diseases (IBD) as clinical trials have led to approval of tofacitinib for ulcerative colitis (UC) and hint at a possible efficacy for Crohn`s disease (CD). However, the impact of tofacitinib on cellular response of monocytes, which are key players in inflammatory responses, has not been investigated so far. We aimed to analyze JAK/STAT-inhibition by tofacitinib in monocytes of IBD patients and healthy controls. Primary monocytes of IBD patients with active disease and healthy controls (n = 18) were analyzed for cytokine expression and phenotype after granulocyte macrophage colony-stimulating factor (GM-CSF)/interferon (IFN)γ-stimulation and tofacitinib pretreatment (1-1000 nM) and capacity to induce Foxp3+-regulatory T cells (Tregs) in cocultures. In total, 20 UC patients and 21 CD patients were included. Additionally, dose-dependent inhibition of JAK/STAT-phosphorylation was analyzed in controls. Pro-inflammatory costimulation with GM-CSF/IFNγ resulted in significant tumor necrosis factor (TNFα) and interleukin (IL)-6 increase, whereas IL-10 expression decreased in monocytes. Tofacitinib modulated the responses of activated monocytes toward a regulatory phenotype through reduced TNFα and IL-6 secretion and enhanced Treg induction in cocultures. However, in monocytes from active IBD patients, higher tofacitinib dosages were needed for blockade of pro-inflammatory cytokines. Tofacitinib induced stronger regulatory phenotypes in monocytes of UC patients, including more effective inhibition of pro-inflammatory pathways and better restoration of anti-inflammatory mechanisms as compared with CD-derived monocytes. Tofacitinib dose-dependently reprograms monocytes toward a more regulatory cell type. This beneficial effect possibly results from selective JAK/STAT-blockade by adequate tofacitinib dosage with inhibition of pro-inflammatory responses and permission of a balance-shift toward regulatory pathways.

Abstract LB-290: Telomere dysfunction is a driver of inflammatory bowel disease

Abstract The molecular instigators and therapeutic strategies for inflammatory bowel disease (IBD) are limited. Here, telomere dysfunction is shown to activate pAtm/c-Abl-mediated phosphorylation and stabilization of Yap1 up-regulates pro-IL-18 expression, a major pro-inflammatory factor in IBD. This signaling axis cooperates with gut microbiome which stimulates cytosolic receptors causing activation of caspase-1, which in turn cleaves pro-IL-18 into its mature IL-18 form. Epithelial-derived IL-18 leads to recruitment of IFNγ-secreting T cells and other immunocytes to provoke classical IBD pathology. Consistent with a role for DNA damage signaling as a driver of IBD, newly diagnosed IBD patient samples exhibited elevated expression of pγH2AX, YAP1, Caspase-1 and IL-18 along with significantly reduced telomere lengths compared to healthy tissue controls. Alleviation of IBD pathology can be achieved in mice via telomerase reactivation in intestinal epithelium or pharmacological inhibition of Atm, Yap1, or caspase-1 as well as antibiotic treatment - each intervention dramatically reducing pro-IL-18 cleavage and inflammation. Thus, telomere dysfunction-induced activation of the Atm-Yap1-pro-IL-18 pathway identifies DNA damage signaling as a key instigator and promoter of IBD, illuminating several novel therapeutic strategies for disease interception and management. Note: This abstract was not presented at the meeting. Citation Format: Deepavali Chakravarti, Asha Multani, Prasenjit Dey, Baoli Hu, Di Zhao, Kyle Chang, Mao Xizeng, Guocan Wang, Christoper Terranova, Wen-ting Liao, Denise Spring, Pingping Hou, Jianhua Zhang, Pablo Okhuysen, Eduardo Vilar, Mary K. Estes, Sarah blutt, Alan Wang, Ronald DePinho. Telomere dysfunction is a driver of inflammatory bowel disease [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr LB-290.

Systemic Molecular Mediators of Inflammation Differentiate Between Crohn's Disease and Ulcerative Colitis, Implicating Threshold Levels of IL-10 and Relative Ratios of Pro-inflammatory Cytokines in Therapy.

Background and AimsFaecal diversion is associated with improvements in Crohn’s disease but not ulcerative colitis, indicating that differing mechanisms mediate the diseases. This study aimed to investigate levels of systemic mediators of inflammation, including fibrocytes and cytokines, [1] in patients with Crohn’s disease and ulcerative colitis preoperatively compared with healthy controls and [2] in patients with Crohn’s disease and ulcerative colitis prior to and following faecal diversion.MethodsBlood samples were obtained from healthy individuals and patients with Crohn’s disease or ulcerative colitis. Levels of circulating fibrocytes were quantified using flow cytometric analysis and their potential relationship to risk factors of inflammatory bowel disease were determined. Levels of circulating cytokines involved in inflammation and fibrocyte recruitment and differentiation were investigated.ResultsCirculating fibrocytes were elevated in Crohn’s disease and ulcerative colitis patients when compared with healthy controls. Smoking, or a history of smoking, was associated with increases in circulating fibrocytes in Crohn’s disease, but not ulcerative colitis. Cytokines involved in fibrocyte recruitment were increased in Crohn’s disease patients, whereas patients with ulcerative colitis displayed increased levels of pro-inflammatory cytokines. Faecal diversion in Crohn’s disease patients resulted in decreased circulating fibrocytes, pro-inflammatory cytokines, and TGF-β1, and increased IL-10, whereas the inverse was observed in ulcerative colitis patients.ConclusionsThe clinical effect of faecal diversion in Crohn’s disease and ulcerative colitis may be explained by differing circulating fibrocyte and cytokine responses. Such differences aid in understanding the disease mechanisms and suggest a new therapeutic strategy for inflammatory bowel disease.

Targeting the Eph/Ephrin System as Anti-Inflammatory Strategy in IBD

Besides their long-known critical role in embryonic growth and in cancer development and progression, erythropoietin-producing hepatocellular carcinoma type B (EphB) receptor tyrosine kinases and their ephrin-B ligands are involved in the modulation of immune responses and in remodeling and maintaining the integrity of the intestinal epithelial layer. These processes are critically involved in the pathogenesis of inflammatory-based disorders of the gut, like inflammatory bowel diseases (IBDs). Accordingly, our aim was to investigate the role of the EphB/ephrin-B system in intestinal inflammation by assessing the local and systemic effects produced by its pharmacological manipulation in 2,4,6-trinitrobenzenesulfonic acid (TNBS)- (Th1-dependent model) and dextran sulphate sodium (DSS)- (innate response model) induced colitis in mice. To this purpose, we administered chimeric Fc-conjugated proteins, allegedly able to uni-directionally activate either forward (ephrin-B1-Fc) or reverse (EphB1-Fc) signaling, and the soluble monomeric EphB4 extracellular domain protein, that, simultaneously interfering with both signaling pathways, acts as EphB/ephrin-B antagonist.The blockade of the EphB/ephrin-B forward signaling by EphB4 and EphB1-Fc was ineffective against DSS-induced colitis while it evoked remarkable beneficial effects against TNBS colitis: it counteracted all the evaluated inflammatory responses and the changes elicited on splenic T lymphocytes subpopulations, without preventing the appearance of a splice variant of ephrin-B2 gene elicited by the haptenating agent in the colon. Interestingly, EphB4, preferentially displacing EphB4/ephrin-B2 interaction over EphB1/ephrin-B1 binding, was able to promote Tumor Necrosis Factor alpha (TNFα) release by splenic mononuclear cells in vitro. On the whole, the collected results point to a potential role of the EphB/ephrin-B system as a pharmacological target in intestinal inflammatory disorders and suggest that the therapeutic efficacy of its blockade seemingly works through the modulation of immune responses, independent of the changes at the transcriptional and translational level of EphB4 and ephrin-B2 genes.

Perspectives on Current and Novel Treatments for Inflammatory Bowel Disease.

New therapeutic strategies in inflammatory bowel disease (IBD) have shifted from symptom control towards treat-to-target algorithms in order to optimize treatment results. The treatment of IBD has evolved with the development of tumor necrosis factor-α inhibitors beyond the conventional therapies. In spite of their long-term effectiveness, many patients do not respond to or cannot sustain treatment with these drugs, which have various side effects. Therefore, the development of new drugs targeting specific pathways in the pathogenesis of IBD has become necessary. Some novel biologics and small molecule drugs have shown potential in IBD clinical trials, providing safe and effective results. In addition, clinicians are now trying to target the dysbiotic microbiome of patients with IBD using fecal microbiota transplantation. New tools such as stem cells have also been developed. The available therapeutic options for IBD are expanding rapidly. In the next few years, physicians will face an unprecedented number of options when choosing the best treatments for patients with IBD. This review provides an overview of recent advances in IBD treatment options.

HDAC inhibitors promote intestinal epithelial regeneration via autocrine TGFβ1 signalling in inflammation.

Intact epithelial barrier function is pivotal for maintaining intestinal homeostasis. Current therapeutic developments aim at restoring the epithelial barrier in inflammatory boweldisease. Histone deacetylase (HDAC) inhibitors are known to modulate immune responses and to ameliorate experimental colitis. However, their direct impact on epithelial barrier function and intestinal wound healing is unknown. In human and murine colonic epithelial cell lines, the presence of the HDAC inhibitors Givinostat and Vorinostat not only improved transepithelial electrical resistance under inflammatory conditions but also attenuated the passage of macromolecules across the epithelial monolayer. Givinostat treatment mediated an accelerated wound closure in scratch assays. In vivo, Givinostat treatment resulted in improved barrier recovery and epithelial wound healing in dextran sodium sulphate-stressed mice. Mechanistically, these regenerative effects could be linked to an increased secretion of transforming growth factor beta1 and interleukin 8, paralleled by differential expression of the tight junction proteins claudin-1, claudin-2 and occludin. Our data reveal a novel tissue regenerative property of the pan-HDAC inhibitors Givinostat and Vorinostat in intestinal inflammation, which may have beneficial implications by repurposing HDAC inhibitors for therapeutic strategies for inflammatory bowel disease.

Maggot protein ameliorates dextran sulphate sodium-induced ulcerative colitis in mice.

Ulcerative colitis (UC) is a common chronic remitting disease but without satisfactory treatment. Maggots are known as a traditional Chinese medicine named as ‘wu gu chong’. The aim of the present study was to investigate the therapeutic effect of the maggot protein on dextran sulphate sodium (DSS)-induced colitis in C57BL/6 mice. In the present study, female C57BL/6 mice were given sterile water containing 3% DSS to establish the model of UC. Mice were randomly divided into five groups: control group (sterile water), model group (DSS), treatment group (DSS + maggot protein), mesalazine group (DSS + mesalazine), and maggot protein group (sterile water + maggot protein). The mental state, defecate traits, and changes in body weights were recorded daily. The disease activity index (DAI) as a disease severity criterion was calculated based on body weights and stool consistency and bleeding. All the mice were killed on the 12th day. Colon length, colon histological changes, and other inflammatory factors were analyzed and evaluated. The results showed that colitis models of mice were established successfully. Administration of maggot protein markedly suppressed the severity of UC compared with the DSS model group. Furthermore, maggot protein potently ameliorated DSS-induced weight loss, colon shortening, and colon histological injury. Moreover, the maggot protein exerted anti-inflammatory effects via inhibition of the activation of the nuclear factor κB (NFκB) signaling pathway. In summary, treatment by maggot protein was able to improve not only the symptoms of colitis, but also the microscopic inflammation in mice with DSS-induced colitis. The present study may have implications for developing an effective therapeutic strategy for inflammatory bowel diseases (IBDs).

Peptides encrypted in the human intestinal microbial-exoproteome as novel biomarkers and immunomodulatory compounds in the gastrointestinal tract

Peptides encrypted in the intestinal microbial-exoproteome mediate the host-microbiota crosstalk, which is disrupted in inflammatory bowel disease (IBD). Here, the MAHMI database was used for the identification of 20 novel intestinal bacterial peptides. Our results revealed that serum IgA levels directed towards the peptides, but not IgG, discriminated healthy controls from IBD patients. Indeed, they also differentiated patients with ulcerative colitis from Crohńs disease and, within them, patients with and without intestinal inflammation. All peptides were immunomodulatory as they changed the intestinal cytokine milieu following human lamina propria mononuclear cells culture (with/out LPS), revealing a Bifidobacterium longum subsp. longum peptide with the highest tolerogenic properties. Therefore, bacterial peptides encrypted in the human gut metaproteome may have utility as non-invasive biomarkers to aid on IBD diagnosis and monitoring. These peptides also display immunomodulatory effects on the intestinal mucosa revealing them as novel functional compounds for non-drug therapeutic strategies in IBD.

Development of the Pediatric Gut Microbiome: Impact on Health and Disease

The intestinal microbiota are important in human growth and development. Microbial composition may yield insights into the temporal development of microbial communities and vulnerabilities to disorders of microbial ecology such as recurrent Clostridium difficile infection. Discoveries of key microbiome features of carbohydrate and amino acid metabolism are lending new insights into possible therapies or preventative strategies for inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS). In this review, we summarize the current understanding of the development of the pediatric gastrointestinal microbiome, the influence of the microbiome on the developing brain through the gut-brain axis, and the impact of dysbiosis on disease development. Dysbiosis is explored in the context of pediatric allergy and asthma, recurrent C. difficile infection, IBD, IBS, and metabolic disorders. The central premise is that the human intestinal microbiome plays a vital role in health and disease, beginning in the prenatal period and extending throughout childhood.

Mucus protectors: Promising therapeutic strategies for inflammatory bowel disease

Inflammatory bowel disease (IBD) is a group of intestinal non-specific inflammatory diseases with unclear pathogenesis, characterized with the impaired intestinal mucosal barriers and the activated immune system. Mucus layer is the vital protector over the intestinal epithelia cells (IECs). Mucus layer with impaired function could not provide isolated protection for IECs and thus proteases and pathogens from the gut lumen attacked and damaged the epithelial layer. Clinical manifestation and histopathology suggest that IBD might be a self-digestive inflammatory disease caused by digestive enzymes. In this review, we specifically focus on the role of intestinal mucosal barriers and aim to summarize the relationship among mucus layer, self-digestion and inflammation in IBD. We also propose a “Two Hits” Self-Digestion theory to explain the role of self-digestion in IBD and assess the application of mucus protectors to treat IBD.