Trefoil factors in inflammatory bowel disease

Targeting the intestinal circadian clock by meal timing ameliorates gastrointestinal inflammation

The expression of clock genes has been observed to be impaired in biopsies from patients with inflammatory bowel disease (IBD). Disruption of circadian rhythms, which occurs in shift workers, has been linked to an increased risk of gastrointestinal diseases, including IBD. The peripheral circadian clock in intestinal epithelial cells (IECs) was previously shown to balance gastrointestinal homeostasis by regulating the microbiome. Here, we demonstrated that the intestinal clock is disrupted in an IBD-relevant mouse model (IL-10-/-). A lack of the intestinal clock gene (Bmal1) in intestinal epithelial cells (IECs) in a chemically and a novel genetically induced colitis model (DSS, Bmal1IEC-/-xIL-10-/-) promoted colitis and dramatically reduced survival rates. Germ-free Bmal1IEC-/- mice colonized with disease-associated microbiota from IL-10-/- mice exhibited increased inflammatory responses, highlighting the importance of the local intestinal clock for microbiota-induced IBD development. Targeting the intestinal clock directly by timed restricted feeding (RF) in IL-10-/- mice restored intestinal clock functions, including immune cell recruitment and microbial rhythmicity; improved inflammatory responses; dramatically enhanced survival rates and rescued the histopathological phenotype. In contrast, RF failed to improve IBD symptoms in Bmal1IEC-/-xIL-10-/- mice, demonstrating the significance of the intestinal clock in determining the beneficial effect of RF. Overall, we provide evidence that intestinal clock dysfunction triggers host immune imbalance and promotes the development and progression of IBD-like colitis. Enhancing intestinal clock function by RF modulates the pathogenesis of IBD and thus could become a novel strategy to ameliorate symptoms in IBD patients.

Diagnostic Procedures for Inflammatory Bowel Disease: Laboratory, Endoscopy, Pathology, Imaging, and Beyond

Diagnosing inflammatory bowel disease (IBD) can often be challenging, and differentiating between Crohn's disease and ulcerative colitis can be particularly difficult. Diagnostic procedures for IBD include laboratory tests, endoscopy, pathological tests, and imaging tests. Serological and stool tests can be easily performed in an outpatient setting and provide critical diagnostic clues. Although endoscopy is an invasive procedure, it offers essential diagnostic information and allows for tissue biopsy and therapeutic procedures. Video capsule endoscopy and device-assisted enteroscopy are endoscopic procedures used to evaluate the small bowel. In addition to endoscopy, magnetic resonance imaging, computed tomography, and ultrasound (US) are valuable tools for small bowel assessment. Among these, US is noninvasive and easily utilized, making its use highly practical in daily clinical practice. Endoscopic biopsy aids in the diagnosis of IBD and is crucial for assessing the histological activity of the disease, facilitating a thorough evaluation of disease remission, and aiding in the development of treatment strategies. Recent advances in artificial intelligence hold promise for enhancing various aspects of IBD management, including diagnosis, monitoring, and precision medicine. This review compiles current procedures and promising future tools for the diagnosis of IBD, providing comprehensive insights.

Emerging strategy towards mucosal healing in inflammatory bowel disease: what the future holds?

For decades, the therapeutic goal of conventional treatment among inflammatory bowel disease (IBD) patients is alleviating exacerbations in acute phase, maintaining remission, reducing recurrence, preventing complications, and increasing quality of life. However, the persistent mucosal/submucosal inflammation tends to cause irreversible changes in the intestinal structure, which can barely be redressed by conventional treatment. In the late 1990s, monoclonal biologics, mainly anti-TNF (tumor necrosis factor) drugs, were proven significantly helpful in inhibiting mucosal inflammation and improving prognosis in clinical trials. Meanwhile, mucosal healing (MH), as a key endoscopic and histological measurement closely associated with the severity of symptoms, has been proposed as primary outcome measures. With deeper comprehension of the mucosal microenvironment, stem cell niche, and underlying mucosal repair mechanisms, diverse potential strategies apart from monoclonal antibodies have been arising or undergoing clinical trials. Herein, we elucidate key steps or targets during the course of MH and review some promising treatment strategies capable of promoting MH in IBD.

Quantitative proteomic screening uncovers candidate diagnostic and monitoring serum biomarkers of ankylosing spondylitis

BACKGROUND

We sought to discover serum biomarkers of ankylosing spondylitis (AS) for diagnosis and monitoring disease activity.

METHODS

We studied biologic-treatment-naïve AS and healthy control (HC) patients' sera. Eighty samples matched by age, gender, and race (1:1:1 ratio) for AS patients with active disease, inactive disease, and HC were analyzed with SOMAscan™, an aptamer-based discovery platform. T-tests tests were performed for high/low-disease activity AS patients versus HCs (diagnosis) and high versus low disease activity (Monitoring) in a 2:1 and 1:1 ratio, respectively, to identify differentially expressed proteins (DEPs). We used the Cytoscape Molecular Complex Detection (MCODE) plugin to find clusters in protein-protein interaction networks and Ingenuity Pathway Analysis (IPA) for upstream regulators. Lasso regression analysis was performed for diagnosis.

RESULTS

Of the 1317 proteins detected in our diagnosis and monitoring analyses, 367 and 167 (317 and 59, FDR-corrected q < .05) DEPs, respectively, were detected. MCODE identified complement, IL-10 signaling, and immune/interleukin signaling as the top 3 diagnosis PPI clusters. Complement, extracellular matrix organization/proteoglycans, and MAPK/RAS signaling were the top 3 monitoring PPI clusters. IPA showed interleukin 23/17 (interleukin 22, interleukin 23A), TNF (TNF receptor-associated factor 3), cGAS-STING (cyclic GMP-AMP synthase, Stimulator of Interferon Gene 1), and Jak/Stat (Signal transducer and activator of transcription 1), signaling in predicted upstream regulators. Lasso regression identified a Diagnostic 13-protein model predictive of AS. This model had a sensitivity of 0.75, specificity of 0.90, a kappa of 0.59, and overall accuracy of 0.80 (95% CI: 0.61-0.92). The AS vs HC ROC curve was 0.79 (95% CI: 0.61-0.96).

CONCLUSION

We identified multiple candidate AS diagnostic and disease activity monitoring serum biomarkers using a comprehensive proteomic screen. Enrichment analysis identified key pathways in AS diagnosis and monitoring. Lasso regression identified a multi-protein panel with modest predictive ability.

Association of GILZ with MUC2, TLR2, and TLR4 in Inflammatory Bowel Disease

Ulcerative colitis (UC) and Crohn's Disease (CD) are chronic relapsing inflammatory diseases that are caused by genetic, environmental, and immune factors. Treatment strategies are currently based on symptomatic control by immunosuppression. The glucocorticoid-induced leucine zipper (GILZ), a mediator of several effects of glucocorticoids, was recently found to be secreted by goblet cells and play a role in inflammatory bowel disease (IBD). This study investigates which genes GILZ is associated with in its role in intestinal barrier functions. We examined datasets from the Gene Expression Omnibus (GEO) and ArrayExpress profiles of the gut of healthy subjects (HSs), as well as UC and CD patients. The human colonic epithelial HT29 cell line was used for in vitro validation experiments. GILZ was significantly correlated with MUC2, TLR2, and TLR4. In particular, an inverse correlation was found between the GILZ and MUC2 in HS and patients with IBD, mostly in those with an active disease. Further, direct pairwise correlations for GILZ/TLR2 and GILZ/TLR4 were found in HSs and UC patients, but not in CD patients. Overall, our results reveal the crosstalk at the transcription level between the GILZ, MUC2, and TLRs in the mucosal barrier through common pathways, and they open up new perspectives in terms of mucosal healing in IBD patients.

Validation of the DNA Methylation Landscape of TFF1/TFF2 in Gastric Cancer

As one of the most frequently occurring tumor types, the increasing incidence of gastric cancer (GC) has been observed in the past decades. The recent studies have illustrated that epigenetic modifications mediated by DNA methyltransferases (DNMTs) are the major epigenetic hallmark in GC progression. Nowadays, DNA methylation was considered to be necessary for inducing the silence of tumor suppressor genes (TSGs). As an important group of peptides, the TFF family has been confirmed to function as a TSG in various kinds of cancers. However, whether TFFs could be modified by DNA methylation in gastric cancer remains unknown. Here, we initially screened out two transcriptional sequencing profiles about GC from Gene Expression Omnibus (GEO) database. The lower expression levels of TFF1 and TFF2 were observed in GC tumor tissues as compared to those in normal tissues. Additionally, utilizing the Kaplan-Meier analysis, the expressions of TFF1 and TFF2 were identified to be associated with the prognosis of GC patients. Subsequently, the integrative analysis was performed to estimate the DNA methylation level of each site in TFF1/TFF2 CpG islands. Importantly, our findings indicated that hyper-methylation of cg01886855 and cg26403416 were separately responsible for the downregulation of TFF1 and TFF2 in GC samples. In addition, utilizing the experiments in vitro, we demonstrated that TFF1/TFF2 could suppress the proliferation of GC cells. Based on these results, we suspected that TFF1/TFF2 could potentially act as the putative tumor suppressor in GC, and these two TFFs were of great value for predicting the overall survival (OS) status in the gastric cancer cohort. Totally, our findings revealed a potential therapeutic method for targeting the TFFs for the treatment of GC.

Surrogate markers of gut dysfunction are related to heart failure severity and outcome-from the BIOSTAT-CHF consortium

BACKGROUND

The contribution of gut dysfunction to heart failure (HF) pathophysiology is not routinely assessed. We sought to investigate whether biomarkers of gut dysfunction would be useful in assessment of HF (eg, severity, adverse outcomes) and risk stratification.

METHODS

A panel of gut-related biomarkers including metabolites of the choline/carnitine- pathway (acetyl-L-carnitine, betaine, choline, γ-butyrobetaine, L-carnitine and trimethylamine-N-oxide [TMAO]) and the gut peptide, Trefoil factor-3 (TFF-3), were investigated in 1,783 patients with worsening HF enrolled in the systems BIOlogy Study to TAilored Treatment in Chronic Heart Failure (BIOSTAT-CHF) cohort and associations with HF severity and outcomes, and use in risk stratification were assessed.

RESULTS

Metabolites of the carnitine-TMAO pathway (acetyl-L-carnitine, γ-butyrobetaine, L-carnitine, and TMAO) and TFF-3 were associated with the composite outcome of HF hospitalization or all-cause mortality at 3 years (hazards ratio [HR] 2.04-2.93 [95% confidence interval {CI} 1.30-4.71] P≤ .002). Combining the carnitine-TMAO metabolites with TFF-3, as a gut dysfunction panel, showed a graded association; a greater number of elevated markers was associated with higher New York Heart Association class (P< .001), higher plasma concentrations of B-type natriuretic peptide (P< .001), and worse outcome (HR 1.90-4.58 [95% CI 1.19-6.74] P≤ 0.008). Addition of gut dysfunction biomarkers to the contemporary BIOSTAT HF risk model also improved prediction for the aforementioned composite outcome (C-statistics P≤ .011, NRI 13.5-21.1 [95% CI 2.7-31.9] P≤ .014).

CONCLUSIONS

A panel of biomarkers of gut dysfunction showed graded association with severity of HF and adverse outcomes. Biomarkers as surrogate markers are potentially useful for assessment of gut dysfunction to HF pathophysiology and in risk stratification.

Advances of Heat Shock Family in Ulcerative Colitis

Ulcerative Colitis (UC) is a non-specific and chronic inflammatory disease of colonic mucosa whose exact etiology and mechanisms remain unclear. The incidence rate of UC is increasing year by year worldwide. What followed is that the medical costs are also rising rapidly. Therefore, it is urgent to understand the pathogenesis and find promising therapeutic targets for UC. Intestinal mucosal homeostasis is essential for normal bowel function, and its imbalance may be an important pathogenesis of UC. Endogenous homeostatic regulators play roles in repairing intestinal mucosa injury after stress. Heat shock family proteins are essential endogenous homeostasis factors. They can inhibit inflammation, regulate intestinal epithelial cells’ survival and death, and promote mucosal healing. Thus, they play important roles in sustaining intestinal mucosal homeostasis and protecting against UC progression. However, the heat shock family may promote UC carcinogenesis. Here, we summarize the advances in the research of the functions of the heat shock family in UC. And this review is an attempt to light on the etiopathogenesis of UC, highlighting the endogenous protective mechanisms, hoping to provide a novel therapeutic target for UC treatment.

Enhanced therapeutic effect on colitis with powder formulations of Painong San associated with the promotion of intestinal adhesion and absorption

ETHNOPHARMACOLOGICAL RELEVANCE

Painong San is a prescription composed of traditional Chinese medicine, which has been used to treat colitis. The Painong San's usage recorded in "Jingui Yaolve" by Zhongjing Zhang in the Later Han Dynasty is powder. However, the decoction is often used in reality. It's unclear which dosage form of Painong San is more suitable for colitis treatment and why?

AIM OF THE STUDY

This study aims to evaluate the different therapeutic effects of Painong San (a powder of Painong San) and Painong Decoction (a decoction of Painong San) on a dextran sulfate sodium salt-induced colitis model and the possible reasons of these different effects.

MATERIALS AND METHODS

The contents of paeoniflorin, naringin, heperidin and neohesperidin in Painong San and Painong decoction were determined by an ultra-performance liquid chromatography system. The therapeutic effect on colitis was evaluated by intragastric administration of Painong San or Painong Decoction in dextran sulfate sodium salt-induced mouse model. The accumulated release rate of Painong San in vitro was analyzed with artificial gastric juice, artificial intestinal juice, and artificial colon juice. The concentrations of four compounds in the blood, intestinal contents, and intestinal fluids were detected by an-ultra performance liquid chromatography-tandem quadrupole mass spectrometry system. In situ intestinal perfusion experiments were used to observe the adhesion of Painong San to the intestine's surface. The expression of Mucin-2 and Trefoil Factor 3 in the colon was studied by immunohistochemistry.

RESULTS

There was no significant difference in the contents of the four compounds in Painong San and Painong Decoction. In vivo, Painong San has a better therapeutic effect than Painong Decoction in the treatment of colitis. Painong San could be released slowly in the simulated human digestion environment in vitro, and more Painong San particles were released on the intestinal surface in the colitis state in the healthy state. Painong San could increase the bioavailability of hesperidin and neohesperidin, and their concentrations in local intestinal tissue, intestinal fluid and intestinal contents. The expression of trefoil Factor 3 protein on the surface of the colon tended to be in the intestinal cavity and overlapped with the expression of mucin-2. Trefoil Factor 3 accumulates in the intestinal cavity of the colon in the state of colitis, which may increase the adhesion of Painong San particles.

CONCLUSION

In conclusion, this experiment proved that Painong San is a more suitable dosage form for the treatment of dextran sulfate sodium salt-induced colitis than Painong Decoction, which may be related to the enhancement of Painong San particle adhesion to the intestine in colitis. This study provides a reference for the selection of clinical dosage forms for traditional Chinese medicine.

The Role and Function of Mucins and Its Relationship to Inflammatory Bowel Disease

Mucus is present throughout the gastrointestinal tract and is essential for regulating gut microbiota homeostasis and preventing disease by protecting the gastrointestinal barrier from microorganisms, pathogens and toxins or other irritants. Mucin (MUC)-2 is a secreted protein produced by epithelial goblet cells as the main component of mucus. Defects in the gastrointestinal tract, such as inflammation and ulcers, cause damage to the mucus barrier, which can worsen mucus quality and reduce mucus production. Therefore, we would like to review the characteristics of MUC2 and its role in intestinal disorders and highlight the importance of further studies. We also investigated whether the role of MUC2 differs between children and adults, ulcerative colitis (UC) and Crohn's disease (CD).

Biomarkers of Necrotizing Enterocolitis: The Search Continues

Necrotizing enterocolitis (NEC) is the most common gastrointestinal (GI) emergency in the neonatal intensive care unit. Despite advances in medical care, mortality and morbidity from NEC have not changed. This is likely due to the lack of a clear understanding of this multifactorial disease, and reliable biomarkers for accurate diagnosis of NEC. Currently, the diagnosis of NEC is made by a combination of nonspecific clinical signs, symptoms, and radiological findings. Though biomarkers have been studied extensively, none offer an acceptable sensitivity or specificity to be used. This review will focus on the available literature on biomarkers for preterm NEC, acknowledging the limitations in studies including the variability of inclusion criteria, and most importantly, the lack of gold standard case definition for NEC.

Association between Promotor hypomethylation of TFF1 and Crohn's Disease

BACKGROUND AND AIM

Epigenetic modifications exhibit promising evidence in etiology and prognosis of important diseases such as inflammatory bowel diseases (IBD). In addition to complex factors involved in IBD, a trend toward better prognosis have been reported in older ages of disease onset. Gastrointestinal mucous layer is one of the important components which is disturbed in the disease course. Integrity of this layer is maintained with an anti-inflammatory factor called trefoil factors (TFF). We investigated the methylation status of TFF1 gene in IBD patients alongside with correlation of its alteration level with age of disease onset.

METHODS

We analyzed the promoter methylation status of TFF1 gene, using the real-time quantitative multiplex methylation specific PCR (QM-MSP). DNA was extracted from colorectal biopsies of 15 Crohn disease cases and 15 healthy controls. Correlation analysis was performed between unmethylated DNA level and age through Pearson correlation coefficient (PPC) test and simple linear regression models.

RESULTS

… Our data didn't provide significant positive correlation of age and TFF1 hypomethylation in Crohn patients (r = .518, p = .058).

CONCLUSIONS

In conclusion, our case-control study didn't show significant alteration in TFF1 methylation status in CD patients. (www.actabiomedica.it).

Mechanisms of Dendrobium officinale polysaccharides in repairing gastric mucosal injuries based on mitogen-activated protein kinases (MAPK) signaling pathway

The present study aimed to investigate the protective effects and molecular mechanisms of Dendrobium officinale polysaccharides on gastric mucosal injuries. Following one week of continuous intragastric administration, a gastric mucosal injury model was established using intragastric administration of anhydrous ethanol. The area of gastric ulcer was measured, the contents of interleukin- 6 (IL-6), epidermal growth factor receptor (EGFR), and thyroid transcription factor 1 (TFF-1) in serum were detected by enzyme linked immunosorbent assay (ELISA), and the expressions of EGFR, TFF-1, IL-6, Raf-2, MAP kinase kinase 1 (MEK1), MEK2, and ERK1 in the gastric tissue were determined utilizing qPCR, Western blotting and immunohistochemistry. Simultaneously, Dendrobium officinale polysaccharides and anhydrous ethanol were added to the gastric mucosal cells (GES1) cultured in vitro, and the protective effects of Dendrobium officinale polysaccharides on cell viability was detected using Cell Counting Kit (CCK)-8. The addition of Dendrobium officinale polysaccharides markedly improved the gastric epithelial defect, inflammatory cell infiltration, and redness and swelling stemmed from gastric mucosal injuries and greatly reduced the area of gastric ulcer. The inhibition rates of gastric ulcer were 48.12 ± 2.98, 42.95 ± 1.52, and 27.96 ± 2.05% in the high, medium, and low concentration Dendrobium officinale polysaccharide groups, respectively. Dendrobium officinale polysaccharides could increase the expressions of EGFR and TFF-1 and decrease the expressions of IL-6, Raf-2, MEK1, MEK2, and ERK1. Dendrobium officinale polysaccharides could reduce the level of inflammatory factors and protect gastric mucosa by inhibiting the expression of MAPK pathway genes and proteins.

Epithelial wound healing in inflammatory bowel diseases: the next therapeutic frontier

Patients with one of the many chronic inflammatory disorders broadly classified as inflammatory bowel disease (IBD) now have a diverse set of immunomodulatory therapies at their disposal. Despite these recent medical advances, complete sustained remission of disease remains elusive for most patients. The full healing of the damaged intestinal mucosa is the primary goal of all therapies. Achieving this requires not just a reduction of the aberrant immunological response, but also wound healing of the epithelium. No currently approved therapy directly targets the epithelium. Epithelial repair is compromised in IBD and normally facilitates re-establishment of the homeostatic barrier between the host and the microbiome. In this review, we summarize the evidence that epithelial wound healing represents an important yet underdeveloped therapeutic modality for IBD. We highlight 3 general approaches that are promising for developing a new class of epithelium-targeted therapies: epithelial stem cells, cytokines, and microbiome engineering. We also provide a frank discussion of some of the challenges that must be overcome for epithelial repair to be therapeutically leveraged. A concerted approach by the field to develop new therapies targeting epithelial wound healing will offer patients a game-changing, complementary class of medications and could dramatically improve outcomes.

Role of MicroRNA in Inflammatory Bowel Disease: Clinical Evidence and the Development of Preclinical Animal Models

The dysregulation of microRNA (miRNA) is implicated in cancer, inflammation, cardiovascular disorders, drug resistance, and aging. While most researchers study miRNA's role as a biomarker, for example, to distinguish between various sub-forms or stages of a given disease of interest, research is also ongoing to utilize these small nucleic acids as therapeutics. An example of a common pleiotropic disease that could benefit from miRNA-based therapeutics is inflammatory bowel disease (IBD), which is characterized by chronic inflammation of the small and large intestines. Due to complex interactions between multiple factors in the etiology of IBD, development of therapies that effectively maintain remission for this disease is a significant challenge. In this review, we discuss the role of dysregulated miRNA expression in the context of clinical ulcerative colitis (UC) and Crohn's disease (CD)-the two main forms of IBD-and the various preclinical mouse models of IBD utilized to validate the therapeutic potential of targeting these miRNA. Additionally, we highlight advances in the development of genetically engineered animal models that recapitulate clinical miRNA expression and provide powerful preclinical models to assess the diagnostic and therapeutic promise of miRNA in IBD.

LINGO3 regulates mucosal tissue regeneration and promotes TFF2 dependent recovery from colitis

Aim: Recovery of damaged mucosal surfaces following inflammatory insult requires diverse regenerative mechanisms that remain poorly defined. Previously, we demonstrated that the reparative actions of Trefoil Factor 3 (TFF3) depend upon the enigmatic receptor, leucine rich repeat and immunoglobulin-like domain containing nogo receptor 2 (LINGO2). This study examined the related orphan receptor LINGO3 in the context of intestinal tissue damage to determine whether LINGO family members are generally important for mucosal wound healing and maintenance of the intestinal stem cell (ISC) compartment needed for turnover of mucosal epithelium.Methods and Results: We find that LINGO3 is broadly expressed on human enterocytes and sparsely on discrete cells within the crypt niche, that contains ISCs. Loss of function studies indicate that LINGO3 is involved in recovery of normal intestinal architecture following dextran sodium sulfate (DSS)-induced colitis, and that LINGO3 is needed for therapeutic action of the long acting TFF2 fusion protein (TFF2-Fc), including a number of signaling pathways critical for cell proliferation and wound repair. LINGO3-TFF2 protein-protein interactions were relatively weak however and LINGO3 was only partially responsible for TFF2 induced MAPK signaling suggesting additional un-identified components of a receptor complex. However, deficiency in either TFF2 or LINGO3 abrogated budding/growth of intestinal organoids and reduced expression of the intestinal ISC gene leucine-rich repeat-containing G-protein coupled receptor 5 (LGR5), indicating homologous roles for these proteins in tissue regeneration, possibly via regulation of ISCs in the crypt niche.Conclusion: We propose that LINGO3 serves a previously unappreciated role in promoting mucosal wound healing.

Chemical Synthesis of TFF3 Reveals Novel Mechanistic Insights and a Gut-Stable Metabolite

TFF3 regulates essential gastro- and neuroprotective functions, but its molecular mode of action remains poorly understood. Synthetic intractability and lack of reliable bioassays and validated receptors are bottlenecks for mechanistic and structure–activity relationship studies. Here, we report the chemical synthesis of TFF3 and its homodimer via native chemical ligation followed by oxidative folding. Correct folding was confirmed by NMR and circular dichroism, and TFF3 and its homodimer were not cytotoxic or hemolytic. TFF3, its homodimer, and the trefoil domain (TFF3_10-50) were susceptible to gastrointestinal degradation, revealing a gut-stable metabolite (TFF3_7-54; t_1/2 > 24 h) that retained its trefoil structure and antiapoptotic bioactivity. We tried to validate the putative TFF3 receptors CXCR4 and LINGO2, but neither TFF3 nor its homodimer displayed any activity up to 10 μM. The discovery of a gut-stable bioactive metabolite and reliable synthetic accessibility to TFF3 and its analogues are cornerstones for future molecular probe development and structure–activity relationship studies.

Humulene Inhibits Acute Gastric Mucosal Injury by Enhancing Mucosal Integrity

This study was designed to determine whether α-humulene, a major constituent in many plants used in fragrances, has a protective role against gastric injury in vivo and in vitro. A rat model of hydrochloric acid (HCl)/ethanol-induced gastritis and human mast cells (HMC-1) were used to investigate the mucosal protective effect of α-humulene. α-Humulene significantly inhibited gastric lesions in HCl/ethanol-induced acute gastritis and decreased gastric acid secretion pyloric ligation-induced gastric ulcers in vivo. In addition, α-humulene reduced the amount of reactive oxygen species and malondialdehyde through upregulation of prostaglandin E2 (PGE2) and superoxide dismutase (SOD). In HMC-1 cells, α-humulene decreased intracellular calcium and increased intracellular cyclic adenosine monophosphate (cAMP) levels, resulting in low histamine levels. α-Humulene also reduced the expression levels of cytokine genes such as interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF) by downregulating nuclear factor-κB (NF-κB) nuclear translocation. Finally, α-humulene upregulated the expression levels of mucin 5AC (Muc5ac), Muc6, trefoil factor 1 (Tff1), trefoil factor 2 (Tff2), and polymeric immunoglobulin receptor (pigr). α-Humulene may attenuate HCl/ethanol-induced gastritis by inhibiting histamine release and NF-κB activation and stimulating antioxidants and mucosal protective factors, particularly Muc5ac and Muc6. Therefore, these data suggest that α-humulene is a potential drug candidate for the treatment of stress-induced or alcoholic gastritis.

The expression of P2Y6 receptor promotes the quality of mucus in colitic mice

In the intestine, mucins are expressed and secreted by goblet cells and enterocytes in a constitutive manner and in response to secretagogues to form a protective mucus layer. This protective barrier is often lost in inflammatory bowel disease (IBD). Interestingly, extracellular nucleotides, through P2Y receptors, were identified as mucin secretagogues in mucinous epithelia. These nucleotides are found in the intestine's extracellular milieu under basal conditions and in higher concentrations in pathologies such as IBD. It was observed that the mucus layer was affected in P2ry6 knockout mice suffering from dextran sodium sulfate (DSS)-induced colitis. P2ry6^-/- mice were more sensitive to DSS-induced colitis, resulting in larger ulcers and increased disease activity index. Interestingly, the absence of P2Y₆ receptor expression negatively affected the mucus quality, as shown by a reduction in sulfomucin staining and the absence of a dense internal fucosylated mucin layer in P2ry6^-/- mice. Hence, we cannot rule out that the absence of P2Y₆ receptors in knockout animals could negatively impact mucin secretion. However, we did not measure a reduction in the number of goblet cells, as previously reported. Instead, the results suggest that goblet cells rapidly discharged mucins to compensate for the mucus layer's increased lability, which resulted in empty goblet cells that are less visible to mucin staining. This study's results, along with previous reports, point toward a protective role for the P2Y₆ receptor in IBD.

The trefoil factor family 1 (TFF-1) and 3 (TFF-3) are upregulated in the saliva, gingival crevicular fluid and serum of periodontitis patients

OBJECTIVE

This study aimed to investigate the levels of trefoil factor family (TFF)-1, TFF-3 and interleukin (IL)-1β in gingival crevicular fluid (GCF), saliva and serum of patients with gingivitis, stage 3 periodontitis and healthy individuals.

MATERIALS AND METHODS

A total of 100 individuals consisting of 25 periodontally healthy, 25 gingivitis and 50 stage 3 periodontitis, were enrolled in the study. Clinical periodontal examinations were recorded and GCF, saliva and serum samples were obtained. TFF-1, TFF-3 and IL-1β were measured by ELISA.

RESULTS

TFF-1 and TFF-3 levels in both GCF, saliva and serum were higher in periodontitis patients than healthy controls (p < .001) and gingivitis group (p < .01). The levels of these peptides in all biofluids were similar between gingivitis and healthy control groups (p > .05). GCF, saliva and serum IL-1β levels were also higher in periodontitis patients than the controls (p < .01). Periodontitis patients had elevated GCF and saliva IL-β levels than gingivitis group (p < .001).

CONCLUSION

Elevated TFF-1 and TFF-3 levels both locally and systemically in periodontitis in parallel to increased IL-1β levels might suggest that these peptides are involved in host response during the periodontal tissue destruction.

Epithelial production of elastase is increased in inflammatory bowel disease and causes mucosal inflammation

Imbalance between proteases and their inhibitors plays a crucial role in the development of Inflammatory Bowel Diseases (IBD). Increased elastolytic activity is observed in the colon of patients suffering from IBD. Here, we aimed at identifying the players involved in elastolytic hyperactivity associated with IBD and their contribution to the disease. We revealed that epithelial cells are a major source of elastolytic activity in healthy human colonic tissues and this activity is greatly increased in IBD patients, both in diseased and distant sites of inflammation. This study identified a previously unrevealed production of elastase 2A (ELA2A) by colonic epithelial cells, which was enhanced in IBD patients. We demonstrated that ELA2A hyperactivity is sufficient to lead to a leaky epithelial barrier. Epithelial ELA2A hyperactivity also modified the cytokine gene expression profile with an increase of pro-inflammatory cytokine transcripts, while reducing the expression of pro-resolving and repair factor genes. ELA2A thus appears as a novel actor produced by intestinal epithelial cells, which can drive inflammation and loss of barrier function, two essentials pathophysiological hallmarks of IBD. Targeting ELA2A hyperactivity should thus be considered as a potential target for IBD treatment.

Ulcerative Colitis-Derived Colonoid Culture: A Multi-Mineral-Approach to Improve Barrier Protein Expression

BACKGROUND

Recent studies demonstrated that Aquamin®, a calcium-, magnesium-rich, multi-mineral natural product, improves barrier structure and function in colonoids obtained from the tissue of healthy subjects. The goal of the present study was to determine if the colonic barrier could be improved in tissue from subjects with ulcerative colitis (UC).

METHODS

Colonoid cultures were established with colon biopsies from 9 individuals with UC. The colonoids were then incubated for a 2-week period under control conditions (in culture medium with a final calcium concentration of 0.25 mM) or in the same medium supplemented with Aquamin® to provide 1.5 - 4.5 mM calcium. Effects on differentiation and barrier protein expression were determined using several approaches: phase-contrast and scanning electron microscopy, quantitative histology and immunohistology, mass spectrometry-based proteome assessment and transmission electron microscopy.

RESULTS

Although there were no gross changes in colonoid appearance, there was an increase in lumen diameter and wall thickness on histology and greater expression of cytokeratin 20 (CK20) along with reduced expression of Ki67 by quantitative immunohistology observed with intervention. In parallel, upregulation of several differentiation-related proteins was seen in a proteomic screen with the intervention. Aquamin®-treated colonoids demonstrated a modest up-regulation of tight junctional proteins but stronger induction of adherens junction and desmosomal proteins. Increased desmosomes were seen at the ultrastructural level. Proteomic analysis demonstrated increased expression of several basement membrane proteins and hemidesmosomal components. Proteins expressed at the apical surface (mucins and trefoils) were also increased as were several additional proteins with anti-microbial activity or that modulate inflammation. Finally, several transporter proteins that affect electrolyte balance (and, thereby affect water resorption) were increased. At the same time, growth and cell cycle regulatory proteins (Ki67, nucleophosmin, and stathmin) were significantly down-regulated. Laminin interactions, matrix formation and extracellular matrix organization were the top three up-regulated pathways with the intervention.

CONCLUSION

A majority of individuals including patients with UC do not reach the recommended daily intake for calcium and other minerals. To the extent that such deficiencies might contribute to the weakening of the colonic barrier, the findings employing UC tissue-derived colonoids here suggest that adequate mineral intake might improve the colonic barrier.

Cornelian Cherry Iridoid-Polyphenolic Extract Improves Mucosal Epithelial Barrier Integrity in Rat Experimental Colitis and Exerts Antimicrobial and Antiadhesive Activities In Vitro

Background and Aims

Inflammatory bowel disease pharmacotherapy, despite substantial progress, is still not satisfactory for both patients and clinicians. In view of the chronic and relapsing disease course and not always effective treatment with adverse effects, attempts to search for new, more efficient, and safer substances are essential and reasonable. This study was designed to elucidate the impact of cornelian cherry iridoid-polyphenolic extract (CE) and loganic acid (LA) on adherent-invasive E. coli growth and adhesion in vitro and to assess the effect of pretreatment with CE or LA on the course of intestinal inflammation in rat experimental colitis compared with sulfasalazine.

Methods

Antibacterial and antiadhesive activities of CE and LA were assessed using microdilution, Int407 cell adherence, and yeast agglutination assays. The colitis model was induced by 2,4,6-trinitrobenzenesulfonic acid. Studied substances were administered intragastrically for 16 days prior to colitis induction. Body weight loss; colon index; histological injuries; IL-23, IL-17, TNF-α, and chemerin levels; and STAT3, Muc2, and TFF3 mRNA expression were evaluated.

Results

Only CE exerted antimicrobial and antiadhesive activities in vitro and alleviated colonic symptoms. CE coadministrated with sulfasalazine was more effective than single compounds in reversing increased concentrations of TNF-α, IL-17, and chemerin and decreased Muc2 mRNA expression.

Conclusions

CE exerted a protective effect against experimental colitis via impaired mucosal epithelial barrier restoration and intestinal inflammatory response attenuation and given concomitantly with sulfasalazine counteracted colitis in a more effective way than sulfasalazine alone, which indicates their synergistic interaction. The beneficial effect of CE may also be due to its bacteriostatic and antiadhesive activities.

Polychemotherapy with Curcumin and Doxorubicin via Biological Nanoplatforms: Enhancing Antitumor Activity

Doxorubicin (DOX) is a well-known chemotherapeutic agent extensively applied in the field of cancer therapy. However, similar to other chemotherapeutic agents such as cisplatin, paclitaxel, docetaxel, etoposide and oxaliplatin, cancer cells are able to obtain chemoresistance that limits DOX efficacy. In respect to dose-dependent side effect of DOX, enhancing its dosage is not recommended for effective cancer chemotherapy. Therefore, different strategies have been considered for reversing DOX resistance and diminishing its side effects. Phytochemical are potential candidates in this case due to their great pharmacological activities. Curcumin is a potential antitumor phytochemical isolated from Curcuma longa with capacity of suppressing cancer metastasis and proliferation and affecting molecular pathways. Experiments have demonstrated the potential of curcumin for inhibiting chemoresistance by downregulating oncogene pathways such as MMP-2, TGF-β, EMT, PI3K/Akt, NF-κB and AP-1. Furthermore, coadministration of curcumin and DOX potentiates apoptosis induction in cancer cells. In light of this, nanoplatforms have been employed for codelivery of curcumin and DOX. This results in promoting the bioavailability and internalization of the aforementioned active compounds in cancer cells and, consequently, enhancing their antitumor activity. Noteworthy, curcumin has been applied for reducing adverse effects of DOX on normal cells and tissues via reducing inflammation, oxidative stress and apoptosis. The current review highlights the anticancer mechanism, side effects and codelivery of curcumin and DOX via nanovehicles.

Trefoil Factor Family Member 2 (TFF2) as an Inflammatory-Induced and Anti-Inflammatory Tissue Repair Factor

Trefoil factor family member 2 (TFF2) is known for its involvement in mucosal repair. Whereas it is overexpressed during inflammatory processes, adding TFF2 leads to an anti-inflammatory effect that would contribute to create the microenvironment required for tissue repair. These properties present TFF2 with a homeostatic pattern during inflammatory processes as illustrated by selected examples.

The protective effect of Bifidobacterium bifidum G9-1 against mucus degradation by Akkermansia muciniphila following small intestine injury caused by a proton pump inhibitor and aspirin

Proton pump inhibitors (PPIs) can alleviate upper gastrointestinal injury but paradoxically exacerbate aspirin (ASA)-induced small intestine injury. In this study, our goal was to simulate this exacerbation by developing an appropriate animal model, which may help in establishing treatments. Methods: Male mice were fed a 60% fructose diet for 9 weeks, then administered 200 mg/kg ASA 3 h before sacrifice. The PPI omeprazole was administered intraperitoneally once daily for 9 weeks. Bifidobacterium bifidum G9-1 was administered orally for the last week. In addition, Akkermansia muciniphila was administered orally for 9 weeks instead of omeprazole. Results: ASA-induced small-intestine injury was observed in high-fructose fed mice. Omeprazole exacerbated ASA-induced intestinal damage, significantly decreased Bifidobacteria levels, and significantly increased A. muciniphila counts in the jejunum. The direct administration of A. muciniphila caused thinning of the jejunum mucus layer, which was also observed in mice that received ASA and omeprazole. On the other hand, the administration of Bifidobacterium bifidum G9-1 inhibited A. muciniphila growth and reduced thinning of the mucus layer. The number of goblet cells in the jejunum was reduced by the administration of ASA and omeprazole, while Bifidobacterium bifidum G9-1 prevented the reduction. Conclusions: These results suggest that omeprazole-induced gut dysbiosis promotes Akkermansia growth and inhibits Bifidobacterium growth, leading to a thinning of the mucus layer through a reduction in goblet cells in the small intestine. Probiotics are, therefore, a promising approach for the treatment of small intestine injury.

Resolution of Inflammation and Gut Repair in IBD: Translational Steps Towards Complete Mucosal Healing

Despite significant recent therapeutic advances, complete mucosal healing remains a difficult treatment target for many patients with inflammatory bowel diseases (IBD) to achieve. Our review focuses on the translational concept of promoting resolution of inflammation and repair as a necessary adjunctive step to reach this goal. We explore the roles of inflammatory cell apoptosis and efferocytosis to promote resolution, the new knowledge of gut monocyte-macrophage populations and their secreted prorepair mediators, and the processes of gut epithelial repair and regeneration to bridge this gap. We discuss the need and rationale for this vision and the tangible steps toward integrating proresolution therapies in IBD.

Comparison of Serum Trefoil Factor-3 to Endoscopy in Diagnosing Helicobacter Pylori Associated Gastric Ulcer

Background and aim of the work:

Helicobacter pylori-associated gastric ulcer (H.pylori-GU) is a serious condition, not only because H.pylori is identified as a grade 1 carcinogen but also because GU is a precancerous condition. Identification and treatment of H.pylori-GU may prevent the sequential progression of dysplasia to carcinoma. Trefoil factor 3 (Tf3) has been implicated in gastric mucosal repair. We compared serum Tf3 to gastric endoscopy in diagnosing H.pylori-GU.

Subjects and methods:

The study included eighty patients suffering from H.pylori induced gastritis, forty of which presented with GU. Gastric endoscopy with slide urease test was used to diagnose H.pylori-GU. Serum Tf3 level was determined using an enzyme immunoassay in all patients as well as thirty healthy volunteers.

Results:

Serum Tf3 showed a significant stepwise decrease among the studied groups. It was significantly lower in patients compared to the control group (p<0.001). Furthermore, it was lower in those with GU compared to those without GU (p=0.023). Based on a receiver operating characteristic curve generated cut off value of 2.4 ng/mL, the diagnostic performance of serum Tf3 as a biomarker of H.pylori-GU revealed a diagnostic specificity of 42.5%, sensitivity of 67.5%, positive and negative predictive values of 54% and 56.67% respectively.

Conclusion:

Although serum Tf3 showed significant variation in H.pylori-GU, further studies are warranted to confirm its role in the pathogenesis of gastric ulcers.

Structure, Function, and Therapeutic Potential of the Trefoil Factor Family in the Gastrointestinal Tract

Trefoil factor family peptides (TFF1, TFF2, and TFF3) are key players in protecting, maintaining, and repairing the gastrointestinal tract. Accordingly, they have the therapeutic potential to treat and prevent a variety of gastrointestinal disorders associated with mucosal damage. TFF peptides share a conserved motif, including three disulfide bonds that stabilize a well-defined three-loop-structure reminiscent of a trefoil. Although multiple functions have been described for TFF peptides, their mechanisms at the molecular level remain poorly understood. This review presents the status quo of TFF research relating to gastrointestinal disorders. Putative TFF receptors and protein partners are described and critically evaluated. The therapeutic potential of these peptides in gastrointestinal disorders where altered mucosal biology plays a crucial role in the underlying etiology is discussed. Finally, areas of investigation that require further research are addressed. Thus, this review provides a comprehensive update on TFF literature as well as guidance toward future research to better understand this peptide family and its therapeutic potential for the treatment of gastrointestinal disorders.

Mucosal Profiling of Pediatric-Onset Colitis and IBD Reveals Common Pathogenics and Therapeutic Pathways

Pediatric-onset colitis and inflammatory bowel disease (IBD) have significant effects on the growth of infants and children, but the etiopathogenesis underlying disease subtypes remains incompletely understood. Here, we report single-cell clustering, immune phenotyping, and risk gene analysis for children with undifferentiated colitis, Crohn's disease, and ulcerative colitis. We demonstrate disease-specific characteristics, as well as common pathogenesis marked by impaired cyclic AMP (cAMP)-response signaling. Specifically, infiltration of PDE4B- and TNF-expressing macrophages, decreased abundance of CD39-expressing intraepithelial T cells, and platelet aggregation and release of 5-hydroxytryptamine at the colonic mucosae were common in colitis and IBD patients. Targeting these pathways by using the phosphodiesterase inhibitor dipyridamole restored immune homeostasis and improved colitis symptoms in a pilot study. In summary, comprehensive analysis of the colonic mucosae has uncovered common pathogenesis and therapeutic targets for children with colitis and IBD.

Hypoxia Inducible Factor-1α: The Curator of Gut Homeostasis

The human gut microbiome is a stratified and resilient ecosystem co-inhabited by a diverse and dynamic pool of microorganisms. Microbial selection, establishment, and colonization are modulated through a complex molecular network of host-microbial interactions. These molecular bioprocesses ensure the taxonomic composition of the mature human gut microbiome. The human gut microbiome plays a vital role in host health; otherwise, any microbial dysbiosis could predispose to the onset of physiological and metabolic disorder/s. Focussed research are being carried out to identify key molecular agents defining gut homeostasis. These molecules hold the potential to develop effective therapeutic solutions for microbial dysbiosis-associated human disorders. Of these, Hypoxia-inducible factor-1α (HIF-1α) is a central player in host-microbial crosstalk to maintain gut homeostasis. Human gut microbial metabolites regulate its cellular stability, which in turn regulates various cellular processes required for the stable gut microbiome. In the present review, an effort has been made to summarize the key role of HIF-1α to maintain gut homeostasis.

Integrated omics profiling of dextran sodium sulfate-induced colitic mice supplemented with Wolfberry (Lycium barbarum)

We used a multi-omics profiling approach to investigate the suppressive effects of 2% Wolfberry (WOL)-enriched diets on dextran sodium sulfate (DSS)-induced colitis in mice. It was observed that in mice fed the WOL diet, the disease activity index, colon shortening, plasma concentrations of matrix metalloproteinase-3 and relative mesenteric fat weight were significantly improved as compared to the DSS group. Results from colon transcriptome and proteome profiles showed that WOL supplementation significantly ameliorated the expression of genes and proteins associated with the integrity of the colonic mucosal wall and colonic inflammation. Based on the hepatic transcriptome, proteome and metabolome data, genes involved in fatty acid metabolism, proteins involved in inflammation and metabolites related to glycolysis were downregulated in WOL mice, leading to lowered inflammation and changes in these molecules may have led to improvement in body weight loss. The integrated nutrigenomic approach thus revealed the molecular mechanisms underlying the ameliorative effect of whole WOL fruit consumption on inflammatory bowel disease.

Engineered E. coli Nissle 1917 for the delivery of matrix-tethered therapeutic domains to the gut

Mucosal healing plays a critical role in combatting the effects of inflammatory bowel disease, fistulae and ulcers. While most treatments for such diseases focus on systemically delivered anti-inflammatory drugs, often leading to detrimental side effects, mucosal healing agents that target the gut epithelium are underexplored. We genetically engineer Escherichia coli Nissle 1917 (EcN) to create fibrous matrices that promote gut epithelial integrity in situ. These matrices consist of curli nanofibers displaying trefoil factors (TFFs), known to promote intestinal barrier function and epithelial restitution. We confirm that engineered EcN can secrete the curli-fused TFFs in vitro and in vivo, and is non-pathogenic. We observe enhanced protective effects of engineered EcN against dextran sodium sulfate-induced colitis in mice, associated with mucosal healing and immunomodulation. This work lays a foundation for the development of a platform in which the in situ production of therapeutic protein matrices from beneficial bacteria can be exploited.

Deoxynivalenol Inhibits Porcine Intestinal Trefoil Factors Expression in Weanling Piglets and IPEC-J2 Cells

Trefoil factors (TFFs) are regulatory peptides playing critical roles in mucosal repair and protection against a variety of insults within the gastrointestinal tract. This work aimed to explore the effects of deoxynivalenol (DON) on intestinal TFFs expression using in vivo and in vitro models. In an animal trial, twenty-four 28-d-old barrows (Duroc × Landrace × Large White; initial body weight = 7.6 ± 0.7 kg) were randomly divided into three treatments for 28 days, including a control diet (0.61 mg DON/kg feed), and two levels of DON-contaminated diets containing 1.28 and 2.89 mg DON/kg feed, respectively. Piglets exposed to DON had lower mRNA expression of TFF1, TFF2, TFF3, as well as Claudin-4 in the intestine (P < 0.05). Dietary DON exposure decreased the protein levels of TFF2 and TFF3 in the jejunum as demonstrated by western blot and immunohistochemistry. In intestinal porcine epithelial cells (IPEC-J2), DON depressed the mRNA expression of TFF2, TFF3, and Claudin-4. Overexpression of sterile alpha motif (SAM) pointed domain E26 transformation-specific (ETS) factor (SPDEF) was found to attenuate DON-induced suppression of TFFs in IPEC-J2 cells. Altogether, our work shows, for the first time, that dietary DON exposure depresses the expression of intestinal TFFs in piglets. Given the fundamental role of TFFs in intestinal mucosal homeostasis, our observations indicate that the DON content in animal feed should be strictly controlled based on the existing regulation for DON.

Inhibition of TFF3 Enhances Sensitivity-and Overcomes Acquired Resistance-to Doxorubicin in Estrogen Receptor-Positive Mammary Carcinoma

Dose-dependent toxicity and acquired resistance are two major challenges limiting the efficacious treatment of mammary carcinoma (MC) with doxorubicin. Herein, we investigated the function of Trefoil Factor 3 (TFF3) in the sensitivity and acquired resistance of estrogen receptor positive (ER+) MC cells to doxorubicin. Doxorubicin treatment of ER+MC cells increased TFF3 expression. The depletion of TFF3 by siRNA or inhibition with a small molecule TFF3 inhibitor (AMPC) synergistically enhanced the efficacy of doxorubicin in ER+MC through the suppression of doxorubicin-induced AKT activation and enhancement of doxorubicin-induced apoptosis. Elevated expression of TFF3 and increased activation of AKT were also observed using a model of acquired doxorubicin resistance in ER+MC cells. AMPC partially re-sensitized the doxorubicin resistant cells to doxorubicin-induced apoptosis. Indeed, doxorubicin resistant ER + MC cells exhibited increased sensitivity to AMPC as a single agent compared to doxorubicin sensitive cells. In vivo, AMPC attenuated growth of doxorubicin sensitive ER+MC xenografts whereas it produced regression of xenografts generated by doxorubicin resistant ER+MC cells. Hence, TFF3 inhibition may improve the efficacy and reduce required doses of doxorubicin in ER+MC. Moreover, inhibition of TFF3 may also be an effective therapeutic strategy to eradicate doxorubicin resistant ER+MC.

Novel potential biomarkers for the diagnosis and monitoring of patients with ulcerative colitis

Unambiguously, great progress has been achieved in the unraveling of more pathological pathways implicated in the development and progression of ulcerative colitis during the last decades. Novel effective drugs that have augmented the management armamentarium have been developed alongside this growing comprehension of the disease, rendering mucosal healing not only a feasible but the optimal goal of every therapy. Clinical evaluation, colonoscopy and biomarkers are the tools used by practitioners for the diagnosis and assessment of the status of the disease in order to achieve clinical remission and mucosal healing for their patients. Among these tools, colonoscopy is the gold method for the cause but is still an invasive, high-cost procedure with possible adverse events such as perforation. While clinical evaluation entails much subjectivity, biomarkers are objective, easily reproducible, non-invasive, cheap and potent surrogate tools of mucosal inflammation. Unfortunately, the well-established, currently in use serum biomarkers, such as C-reactive protein, erythrocyte sedimentation rate and others, do not display sufficiently acceptable sensitivity and specificity rates for the diagnosis of ulcerative colitis and, most importantly, do not represent precisely the mucosal inflammation status of the disease. Therefore, the discovery of new serum biomarkers has been the cause of several studies attempting to discover an "optimal" serum biomarker during the recent years. After thorough research, collection and examination of current data, this review focuses on and selectively presents promising, potential, novel serum biomarkers of ulcerative colitis as they are indicated by studies on the patient over the last years.

Hypoxic Environment Promotes Barrier Formation in Human Intestinal Epithelial Cells through Regulation of MicroRNA 320a Expression

Intestinal epithelial cells (IECs) are exposed to the low-oxygen environment present in the lumen of the gut. These hypoxic conditions on one hand are fundamental for the survival of the commensal microbiota and, on the other hand, favor the formation of a selective semipermeable barrier, allowing IECs to transport essential nutrients/water while keeping the sterile internal compartments separated from the lumen containing commensals. The hypoxia-inducible factor (HIF) complex, which allows cells to respond and adapt to fluctuations in oxygen levels, has been described as a key regulator in maintaining IEC barrier function by regulating their tight junction integrity. In this study, we sought to better evaluate the mechanisms by which low oxygen conditions impact the barrier function of human IECs. By profiling miRNA expression in IECs under hypoxia, we identified microRNA 320a (miRNA-320a) as a novel barrier formation regulator. Using pharmacological inhibitors and short hairpin RNA-mediated silencing, we could demonstrate that expression of this microRNA (miRNA) was HIF dependent. Importantly, using overexpression and knockdown approaches of miRNA-320a, we could confirm its direct role in the regulation of barrier function in human IECs. These results reveal an important link between miRNA expression and barrier integrity, providing a novel insight into mechanisms of hypoxia-driven epithelial homeostasis.

Deoxynivalenol inhibits the expression of trefoil factors (TFF) by intestinal human and porcine goblet cells

Trefoil factors (TFFs) are bioactive peptides expressed by several epithelia, including the intestine, where they regulate key functions such as tissue regeneration, barrier function and inflammation. Although food-associated mycotoxins, including deoxynivalenol (DON), are known to impact many intestinal functions, modulation of TFFs during mycotoxicosis has never been investigated. Here, we analyzed the effect of DON on TFFs expression using both human goblet cells (HT29-16E cells) and porcine intestinal explants. Results showed that very low doses of DON (nanomolar range) inhibit the secretion of TFFs by human goblet cells (IC₅₀ of 361, 387 and 243 nM for TFF1, 2 and 3, respectively) and prevent wound healing. RT-qPCR analysis demonstrated that the inhibitory effect of DON is related to a suppression of TFFs mRNA expression. Experiments conducted on porcine intestinal explants confirmed the results obtained on cells. Finally, the use of specific inhibitors of signal pathways demonstrated that DON-mediated suppression of TFFs expression mainly involved Protein Kinase R and the MAP kinases (MAPK) p38 and ERK1/2. Taken together, our results show for the first time that at very low doses, DON suppresses the expression and production of intestinal TFFs and alters wound healing. Given the critical role of TFFs in tissue repair, our results suggest that DON-mediated suppression of TFFs contributes to the alterations of intestinal integrity the caused by this toxin.

Differential urinary proteins to diagnose coronary heart disease based on iTRAQ quantitative proteomics

Coronary artery disease (CAD) is a manifestation of systemic atherosclerotic disease. It is assessed by intervention or traditional scoring risk factors. Diagnosis is limited by inaccurate and invasive methods. Developing noninvasive methods to screen for the risk of CAD is a major challenge. We aimed to identify urinary proteins associated with CAD. We utilized iTRAQ labeling followed by 2D LC-MS/MS to compare the urinary proteome of CAD patients to healthy cohorts. The multiple reaction monitoring (MRM) was used to verify the differential proteins. ROC analysis based on MRM data was used to evaluate the diagnostic application. A total of 876 proteins were quantified, and 100 differential proteins were found. Functional analysis revealed that the differential proteins were mainly associated with Liver X Receptor/Retinoid X Receptor (LXR/RXR) pathway activation, atherosclerosis signaling, production of nitric oxide and reactive oxygen species, and the top upstream regulator of the differential proteins by IPA analysis indicated to the APOE. Nineteen differential proteins were verified by MRM analysis. ROC based on MRM data revealed that the combination of two proteins (APOD and TFF1) could diagnose CAD with 85% sensitivity and 99% specificity (AUC 0.95). The urinary proteome might reflect the pathophysiological changes in CAD and be used for the clinical study of CAD.

Macrophages promote epithelial proliferation following infectious and non-infectious lung injury through a Trefoil factor 2-dependent mechanism

Coordinated efforts between macrophages and epithelia are considered essential for wound healing, but the macrophage-derived molecules responsible for repair are poorly defined. This work demonstrates that lung macrophages rely upon Trefoil factor 2 to promote epithelial proliferation following damage caused by sterile wounding, Nippostrongylus brasiliensis or Bleomycin sulfate. Unexpectedly, the presence of T, B, or ILC populations was not essential for macrophage-driven repair. Instead, conditional deletion of TFF2 in myeloid-restricted CD11c^Cre TFF2 ^flox mice exacerbated lung pathology and reduced the proliferative expansion of CD45^- EpCAM⁺ pro-SPC⁺ alveolar type 2 cells. TFF2 deficient macrophages had reduced expression of the Wnt genes Wnt4 and Wnt16 and reconstitution of hookworm-infected CD11c^Cre TFF2^flox mice with rWnt4 and rWnt16 restored the proliferative defect in lung epithelia post-injury. These data reveal a previously unrecognized mechanism wherein lung myeloid phagocytes utilize a TFF2/Wnt axis as a mechanism that drives epithelial proliferation following lung injury.

Renal expression of trefoil factor 3 mRNA in association with tubulointerstitial fibrosis in IgA nephropathy

Aim

Trefoil factor 3 (TFF3) is a small peptide that is involved in mucosal protection. TFF3 is widely expressed in multiple tissues including kidney tissue. Previous studies have reported that the levels of urinary TFF3 are significantly increased in patients with chronic kidney disease. The aim of this study is to detect the TFF3 mRNA in kidney and elucidate the relationship between renal TFF3 mRNA and tubulointerstitial fibrosis in IgA nephropathy (IgAN).

Methods

We investigated the renal mRNA expression of TFF3 by real‐time PCR analysis in biopsy specimens from patients with IgAN, other glomerulonephritis (OGN) and minor glomerular abnormalities (MGA). We also determined the renal localization of TFF3 and the levels of urinary TFF3 by immunostaining and ELISA, respectively.

Results

The renal TFF3 mRNA expression was significantly associated with the urinary TFF3 secretion and the tubulointerstitial fibrosis score in the IgAN group alone. Immunostaining of the renal specimen of IgAN patients revealed that TFF3 is located in the renal tubular epithelial cells. The locations were almost the same as those that showed uromodulin positivity; specifically, the thick ascending limb (TAL) of the loop of Henle and the early portion of the distal tubule. The urinary TFF3 levels were positively correlated with the levels of urinary biomarkers of tubulointerstitial injury in such patients.

Conclusion

Renal TFF3 mRNA is associated with renal tubulointerstitial fibrosis in IgAN patients. The TFF3 located in the renal tubular epithelial cells may play a role in the progression of tubulointerstitial fibrosis in IgAN patients.

Trefoil factor 3 is a peptide that, generally speaking, has protective functions in epithelial biology. This study reports that TFF3 is increased in IgA nephropathy and correlates with injury. Whether TFF3 is functionally a counter‐regulatory, protective factor or whether its overexpression denotes a pathogenic role remains an outstanding question.

Trefoil factor 3 mediation of oncogenicity and chemoresistance in hepatocellular carcinoma is AKT-BCL-2 dependent

The efficacious treatment of hepatocellular carcinoma (HCC) remains a challenge, partially being attributed to intrinsic chemoresistance. Previous reports have observed increased TFF3 expression in HCC. Herein, we investigated the functional role of TFF3 in progression of HCC, and in both intrinsic and acquired chemoresistance. TFF3 expression was observed to be upregulated in HCC and associated with poor clinicopathological features and worse patient survival outcome. Functionally, forced expression of TFF3 in HCC cell lines increased cell proliferation, cell survival, anchorage-independent and 3D matrigel growth, cell invasion and migration, and in vivo tumor growth. In contrast, depleted expression of TFF3 decreased the oncogenicity of HCC cells as indicated by the above parameters. Furthermore, forced expression of TFF3 decreased doxorubicin sensitivity of HCC cells, which was attributed to increased doxorubicin efflux and cancer stem cell-like behavior of Hep3B cells. In contrast, depletion of TFF3 increased doxorubicin sensitivity and decreased cancer stem cell-like behavior of Hep3B cells. Correspondingly, TFF3 expression was markedly increased in Hep3B cells with acquired doxorubicin resistance, while the depletion of TFF3 resulted in re-sensitization of the Hep3B cells to doxorubicin. The increased doxorubicin efflux and enhanced cancer stem cell-like behavior of the doxorubicin-resistant Hep3B cells was observed to be dependent on TFF3 expression. In addition, we determined that TFF3-stimulated oncogenicity and chemoresistance in HCC cells was mediated by AKT-dependent expression of BCL-2. Hence, therapeutic inhibition of TFF3 should be considered to hinder HCC progression and overcome intrinsic and acquired chemoresistance in HCC.

Immunopathophysiology of inflammatory bowel disease: how genetics link barrier dysfunction and innate immunity to inflammation

Inflammatory bowel diseases (IBD) comprise a distinct set of clinical symptoms resulting from chronic or relapsing immune activation and corresponding inflammation within the gastrointestinal (GI) tract. Diverse genetic mutations, encoding important aspects of innate immunity and mucosal homeostasis, combine with environmental triggers to create inappropriate, sustained inflammatory responses. Recently, significant advances have been made in understanding the interplay of the intestinal epithelium, mucosal immune system, and commensal bacteria as a foundation of the pathogenesis of inflammatory bowel disease. Complex interactions between specialized intestinal epithelial cells and mucosal immune cells determine different outcomes based on the environmental input: the development of tolerance in the presence of commensal bacterial or the promotion of inflammation upon recognition of pathogenic organisms. This article reviews key genetic abnormalities involved in inflammatory and homeostatic pathways that enhance susceptibility to immune dysregulation and combine with environmental triggers to trigger the development of chronic intestinal inflammation and IBD.

Modulating bacterial and gut mucosal interactions with engineered biofilm matrix proteins

Extracellular appendages play a significant role in mediating communication between bacteria and their host. Curli fibers are a class of bacterial fimbria that is highly amenable to engineering. We demonstrate the use of engineered curli fibers to rationally program interactions between bacteria and components of the mucosal epithelium. Commensal E. coli strains were engineered to produce recombinant curli fibers fused to the trefoil family of human cytokines. Biofilms formed from these strains bound more mucins than those producing wild-type curli fibers, and modulated mucin rheology as well. When treated with bacteria producing the curli-trefoil fusions mammalian cells behaved identically in terms of their migration behavior as when they were treated with the corresponding soluble trefoil factors. Overall, this demonstrates the potential utility of curli fibers as a scaffold for the display of bioactive domains and an untapped approach to rationally modulating host-microbe interactions using bacterial matrix proteins.

Production of Monoclonal Antibodies against Human Trefoil Factor 3 and Development of a Modified-Sandwich ELISA for Detection of Trefoil Factor 3 Homodimer in Saliva

Background

Human trefoil factor (TFF) peptides consist of three members: TFF1, TFF2 and TFF3. TFF3 is the most abundant TFF peptide in saliva. TFF3 homodimer was suggested to be involved in apoptosis inhibition and malignancy. Determination of TFF3 homodimer expression profiles in saliva may lead to new information about oral biology and diseases. The objective of this study was to generate monoclonal antibodies (mAbs) against TFF3 and apply the produced mAbs for the establishment of ELISA for quantification of dimeric TFF3 in saliva.

Results

With our modified hybridoma technique, three hybridoma clones producing anti-TFF3 mAbs having IgG isotype were generated. The mAbs were specific for TFF3 with no cross-reactivity to other TFFs. Using the generated mAbs, a modified-sandwich ELISA with high sensitivity for the quantification of dimeric TFF3 in saliva was developed. Using this ELISA, the amount of dimeric TFF3 in saliva could be measured.

Conclusions

A modified-sandwich ELISA for the quantification of TFF3 dimeric form was established. The established ELISA will be a valuable tool for facilitating the investigation of the physiological roles and the diagnostic values of TFF3 in oral diseases. The concept of this modified-sandwich ELISA may be applied for the determination of other homodimeric peptides of interest.

Genetic and Transcriptomic Bases of Intestinal Epithelial Barrier Dysfunction in Inflammatory Bowel Disease

BACKGROUND

Intestinal barrier defects are common in patients with inflammatory bowel disease (IBD). To identify which components could underlie these changes, we performed an in-depth analysis of epithelial barrier genes in IBD.

METHODS

A set of 128 intestinal barrier genes was selected. Polygenic risk scores were generated based on selected barrier gene variants that were associated with Crohn's disease (CD) or ulcerative colitis (UC) in our study. Gene expression was analyzed using microarray and quantitative reverse transcription polymerase chain reaction. Influence of barrier gene variants on expression was studied by cis-expression quantitative trait loci mapping and comparing patients with low- and high-risk scores.

RESULTS

Barrier risk scores were significantly higher in patients with IBD than controls. At single-gene level, the associated barrier single-nucleotide polymorphisms were most significantly enriched in PTGER4 for CD and HNF4A for UC. As a group, the regulating proteins were most enriched for CD and UC. Expression analysis showed that many epithelial barrier genes were significantly dysregulated in active CD and UC, with overrepresentation of mucus layer genes. In uninflamed CD ileum and IBD colon, most barrier gene levels restored to normal, except for MUC1 and MUC4 that remained persistently increased compared with controls. Expression levels did not depend on cis-regulatory variants nor combined genetic risk.

CONCLUSIONS

We found genetic and transcriptomic dysregulations of key epithelial barrier genes and components in IBD. Of these, we believe that mucus genes, in particular MUC1 and MUC4, play an essential role in the pathogenesis of IBD and could represent interesting targets for treatment.

Localization of trefoil factor family peptide 3 (TFF3) in epithelial tissues originating from the three germ layers of developing mouse embryo

Trefoil factor family (TFF) peptides are involved in the maintenance of epithelial integrity and epithelial restitution. Mature epithelial tissues originate from different embryonic germ layers. The objective of this research was to explore the presence and localization of TFF3 peptide in mouse embryonic epithelia and to examine if the occurrence of TFF3 peptide is germ layer-dependent. Mouse embryos (14-18 days old) were fixed in 4% paraformaldehyde and embedded in paraffin. Immunohistochemistry was performed with affinity purified rabbit anti-TFF3 antibody, goat anti-rabbit biotinylated secondary antibody and streptavidin-horseradish peroxidase, followed by 3,3'-diaminobenzidine. TFF3 peptide was present in the gastric and intestinal mucosa, respiratory mucosa in the upper and lower airways, pancreas, kidney tubules, epidermis, and oral cavity. The presence and localization of TFF3 peptide was associated with the embryonic stage and tissue differentiation. TFF3 peptide distribution specific to the germ layers was not observed. The role of TFF3 peptide in cell migration and differentiation, immune response, and apoptosis might be associated with specific embryonic epithelial cells. TFF3 peptide may also be considered as a marker for mucosal maturation.

Proteolytic effects of gingipains on trefoil factor family peptides

OBJECTIVES

The present study was aimed to determine whether trefoil factor family (TFF) peptides which were generally considered to be resistant to proteolysis could be digested by gingipains, a major proteinases produced by Porphyromonas gingivalis.

MATERIALS AND METHODS

Recombinant human TFF1, TFF2, and TFF3 peptides were used as substrates. Gingipains including arginine gingipain (RgpB) and lysine gingipain (Kgp) were used as enzymes. Trypsin was used as a control protease. Matrix-assisted laser desorption/ionization with time-of-flight / time-of-flight (MALDI-TOF/TOF) and liquid chromatography mass spectrometry (LC-MS) were used for analyzing peptide mass signals and amino acid sequences of digested TFF peptides.

RESULTS

MALDI-TOF/TOF analyses demonstrated that Kgp, RgpB, and trypsin were able to cleave TFF1 and TFF2 peptides, resulting in different patterns of digested fragments. However, impurity in recombinant TFF3 peptide substrates affected the interpretations of enzymatic reaction by MALDI-TOF/TOF. LC-MS analyses demonstrated that identified fragments of TFF1, TFF2, and TFF3 from digestion by gingipains were similar to those by trypsin.

CONCLUSIONS

Using MALDI-TOF/TOF and LC-MS, the present study provides new information that gingipains containing trypsin-like activities are able to digest TFF peptides.

CLINICAL RELEVANCE

The proteolytic effects of gingipains on TFF peptides may be responsible for reduction of salivary TFF peptides in chronic periodontitis patients. Further investigations to determine the pathological effects of gingipains on TFF peptides in saliva and periodontal tissues of patients with chronic periodontitis would be of interest.