Role In Mucosal Inflammation Research Articles

Human intestinal stromal cells promote homeostasis in normal mucosa but inflammation in Crohn’s disease in a retinoic acid–deficient manner

Intestinal stromal cells (SCs), which synthesize the extracellular matrix that gives the mucosa its structure, are newly appreciated to play a role in mucosal inflammation. Here we show that human intestinal vimentin+CD90+SMA- SCs synthesize retinoic acid (RA) at levels equivalent to intestinal epithelial cells, a function in the human intestine previously attributed exclusively to epithelial cells. Crohn’s disease SCs (Crohn’s SCs), however, synthesized markedly less RA than SCs from healthy intestine (Normal SCs). We also show that microbe-stimulated Crohn’s SCs, which are more inflammatory than stimulated Normal SCs, induced less RA-regulated differentiation of mucosal DCS (circulating pre-DCs and monocyte-derived DCs), leading to the generation of more potent inflammatory IFN-γhi/IL-17hi T cells than Normal SCs. Explaining these results, Crohn’s SCs expressed more DHRS3, a retinaldehyde reductase that inhibits retinol conversion to retinal, and thus synthesized less RA than Normal SCs. These findings uncover a microbe–SC–DC crosstalk in which luminal microbes induce Crohn’s disease SCs to initiate and perpetuate inflammation through impaired synthesis of RA.

Atovaquone attenuates experimental colitis by reducing neutrophil infiltration of colonic mucosa.

Ulcerative colitis (UC) is a chronic relapsing disease featuring aberrant accumulation of neutrophils in colonic mucosa and the luminal space. Although significant advances in UC therapy have been made with the development of novel biologics and small molecules targeting immune responses, success of most current therapies is still limited, with significant safety concerns. Thus, there is a need to develop additional safe and effective therapies for the treatment of UC. Antimalarial drugs have been safely used for many years to resolve tissue inflammation and the associated pathologies. Atovaquone is a recent FDA-approved antimalarial drug that has shown anti-viral and tumor-suppressive properties in vitro however, its role in mucosal inflammation has not been evaluated. Using pre-clinical murine DSS-induced colitis model combined with complementary in vivo peritonitis and ex vivo human neutrophil activation and chemotaxis assays we investigated functional and mechanistic impacts of atovaquone on disease resolution and neutrophil trafficking. We demonstrate that atovaquone promotes resolution of DSS-induced murine colitis by reducing neutrophil accumulation in the inflamed colonic mucosa. Mechanistically, we show that atovaquone suppressed induction of CD11b expression in neutrophils, reducing their polarization and migratory ability. Thus, our findings identify a new role of atovaquone in promoting resolution of mucosal inflammation, supporting the idea of potential repurposing of this FDA-approved drug as UC therapeutic.

Intestinal SALSA/dmbt1 levels are decreased in prematurely born infants.

The first months of life represent a crucial time period for an infant. Alongside establishing the early microbiome, the mucosal immunological homeostasis is being developed. Both processes may be perturbed in prematurely born infants. The glycoprotein SALSA plays a role in mucosal inflammation and microbial clearance. It is one of the most abundant molecules on the intestinal mucosal surfaces in early life. SALSA binds to many types of microbes and host defence molecules like IgA, C1q and collectin molecules. We here describe the development in faecal SALSA levels during the first three months of life. During these 90days, the median SALSA level in full-term babies decreased from 1100μg/mL (range 49-17000μg/mL) to 450μg/mL (range 33-1000μg/mL). Lower levels of SALSA were observed in prematurely born infants in the same time period. Our novel observation thus indicates an impact of prematurity on an important component of the infant intestinal immune system. Changes in SALSA in early life may have an effect on the early establishment of the human microbiome.

The Role of Eicosanoids in Gynecological Malignancies.

Eicosanoids, bio-active lipid molecules, evoke a multitude of biological effects that directly affect cancer cells and indirectly affect tumor microenvironment. An emerging role has been shown for eicosanoids in the pathogenesis of gynecological malignancies which include cancers of the vulva, vagina, cervix, uterine, and ovary. Eicosanoid biosynthesis pathways start at the metabolism of phospholipids by phospholipase A2 then proceeding to one of three pathways: the cyclooxygenase (COX), lipoxygenase (LOX), or P450 epoxygenase pathways. The most studied eicosanoid pathways include COX and LOX; however, more evidence is appearing to support further study of the P450 epoxygenase pathway in gynecologic cancers. In this review, we present the current knowledge of the role of COX, LOX and P450 pathways in the pathogenesis of gynecologic malignancies. Vulvar and vaginal cancer, the rarest subtypes, there is association of COX-2 expression with poor disease specific survival in vulvar cancer and, in vaginal cancer, COX-2 expression has been found to play a role in mucosal inflammation leading to disease susceptibility and transmission. Cervical cancer is associated with COX-2 levels 7.4 times higher than in healthy tissues. Additionally, HPV elevates COX-2 levels through the EGFR pathway and HIV promotes elevated COX-2 levels in cervical tissue as well as increases PGE2 levels eliciting inflammation and progression of cancer. Evidence supports significant roles for both the LOX and COX pathways in uterine cancer. In endometrial cancer, there is increased expression of 5-LOX which is associated with adverse outcomes. Prostanoids in the COX pathway PGE2 and PGF2α have been shown to play a significant role in uterine cancer including alteration of proliferation, adhesion, migration, invasion, angiogenesis, and the inflammatory microenvironment. The most studied gynecological malignancy in regard to the potential role of eicosanoids in tumorigenesis is ovarian cancer in which all three pathways have shown to be associated or play a role in ovarian tumorigenesis directly on the tumor cell or through modulation of the tumor microenvironment. By identifying the gaps in knowledge, additional pathways and targets could be identified in order to obtain a better understanding of eicosanoid signaling in gynecological malignancies and identify potential new therapeutic approaches.

Infiltration pattern of gammadelta T cells and its association with local inflammatory response in the nasal mucosa of patients with allergic rhinitis.

gammadelta (γδ) T cells play important roles in allergic lower airway inflammation. However, little is known about their infiltration pattern in the nasal mucosa during upper airway inflammation. This study investigated γδ T cell distribution in nasal tissues of allergic rhinitis (AR) patients and the relationship between γδ T cells and other inflammatory cell types. A total of 30 patients with septal deviation were examined, including 22 with and 8 without AR. The localization of γδ T cells and other cells (eosinophils, neutrophils, mast cells, macrophages, B cells, cluster of differentiation [CD]4+ T cells, CD8+ T cells, regulatory T cells [Tregs], interferon [IFN]-γ+ cells, interleukin [IL]17+ cells, and IL10+ cells) was evaluated by histological analysis and immunohistochemistry. T helper cell (Th)1/Th2/Th17 and Treg gene expression was analyzed by quantitative polymerase chain reaction (PCR). γδ T cells were localized in the epithelium or subepithelial region of nasal mucosa, and their infiltration was higher in AR patients relative to control subjects. The number of γδ T cells was associated with the presence of eosinophils, macrophages, mast cells, B cells, CD8+ T cells, Forkhead box (Fox)p3+ Tregs, IL17+ cells, and IL10+ cells but not of neutrophils or IFN-γ+ cells. The messenger RNA (mRNA) level of a γδ T cell subunit was positively correlated with those of Th1 genes (T-bet and IFN-γ), Th2 cytokine (C-C motif chemokine ligand 18), and Treg genes (Foxp3 and IL10). γδ T cells play multiple roles in mucosal inflammation in AR including immune surveillance and adaptive and innate immune responses.

Role of mucosal inflammation in irritable bowel syndrome

Role of mucosal inflammation in irritable bowel syndrome

Glucocorticoids Inhibit Group 3 Innate Lymphocyte IL-22 Production.

Glucocorticoids (GCs) are commonly prescribed to patients with a variety of inflammatory disorders, including inflammatory bowel disease (IBD). GCs mediate their immunomodulatory effects through many different mechanisms and target multiple signaling pathways. The GC dexamethasone downmodulates innate and adaptive immune cell activation. IBD is the manifestation of a dysregulated immune response involving many different immune cells. Group 3 innate lymphocytes (ILC3s) have critical roles in mucosal inflammation. ILC3s secrete high levels of the cytokine IL-22, promoting epithelial proliferation, antimicrobial peptides, and mucins. In this study, we examined the effects of dexamethasone on IL-22 production by ILC3s. We found that dexamethasone suppressed IL-23-mediated IL-22 production in human and mouse ILC3s. This was mediated in part through dexamethasone modulation of the NF-κB pathway. Inhibition of NF-κB signaling with a small molecule inhibitor also downmodulated IL-23- and IL-1β-mediated IL-22 production in ILC3s. These findings implicate NF-κB as a regulator of IL-22 in ILC3s and likely have repercussions on GC treatment of IBD patients.

Glucocorticoids inhibit group 3 innate lymphocyte IL-22 production

Abstract Glucocorticoids (GCs) are commonly prescribed to patients with a variety of inflammatory disorders, including inflammatory bowel disease (IBD). IBD is the manifestation of a dysregulated mucosal immune response, usually against commensal bacteria, involving many different immune cells. GCs mediate their immunomodulatory effects through many different mechanisms and target multiple signaling pathways. The GC dexamethasone down-modulates both innate and adaptive immune cell activation. Group 3 innate lymphocytes (ILC3s) have critical roles in mucosal inflammation. ILC3s secrete high levels of the cytokine IL-22, promoting epithelial proliferation, antimicrobial peptides and mucins. The effects of dexamethasone on T cell function are well described, however, it is not known if dexamethasone modulates the critical function of ILC3s or if dexamethasone regulates the cytokine IL-22. In this study, we examined the effects of dexamethasone on IL-22 production by ILC3s. We found that dexamethasone suppressed IL-23-mediated IL-22 production in homeostatic and activated human and mouse ILC3s. Dexamethasone did not modulate the IL-23 canonical signaling pathway of JAK2/STAT3, but did suppress phosphorylation of IkBa, an important regulator in NF-kB activation. These findings implicate NF-kB as a regulator of IL-22 production in ILC3s and have likely repercussions on GC treatment of IBD patients.

The Proton-activated Receptor GPR4 Modulates Intestinal Inflammation.

During active inflammation, intraluminal intestinal pH is decreased in patients with inflammatory bowel disease [IBD]. Acidic pH may play a role in IBD pathophysiology. Recently, proton-sensing G-protein coupled receptors were identified, including GPR4, OGR1 [GPR68], and TDAG8 [GPR65]. We investigated whether GPR4 is involved in intestinal inflammation. The role of GPR4 was assessed in murine colitis models by chronic dextran sulphate sodium [DSS] administration and by cross-breeding into an IL-10 deficient background for development of spontaneous colitis. Colitis severity was assessed by body weight, colonoscopy, colon length, histological score, cytokine mRNA expression, and myeloperoxidase [MPO] activity. In the spontaneous Il-10-/- colitis model, the incidence of rectal prolapse and characteristics of lamina propria leukocytes [LPLs] were analysed. Gpr4-/- mice showed reduced body weight loss and histology score after induction of chronic DSS colitis. In Gpr4-/-/Il-10-/- double knock-outs, the onset and progression of rectal prolapse were significantly delayed and mitigated compared with Gpr4+/+/Il-10-/- mice. Double knock-out mice showed lower histology scores, MPO activity, CD4+ T helper cell infiltration, IFN-γ, iNOS, MCP-1 [CCL2], CXCL1, and CXCL2 expression compared with controls. In colon, GPR4 mRNA was detected in endothelial cells, some smooth muscle cells, and some macrophages. Absence of GPR4 ameliorates colitis in IBD animal models, indicating an important regulatory role in mucosal inflammation, thus providing a new link between tissue pH and the immune system. Therapeutic inhibition of GPR4 may be beneficial for the treatment of IBD.

Tripartite motif-containing (TRIM) 21 negatively regulates intestinal mucosal inflammation through inhibiting TH1/TH17 cell differentiation in patients with inflammatory bowel diseases

Tripartite motif-containing (TRIM) 21 has been implicated in the pathogenesis of several types of autoimmune diseases. We sought to elucidate TRIM21 expression in patients with inflammatory bowel diseases (IBDs) and its role in regulating intestinal mucosal inflammation. TRIM21 expression was analyzed in the inflamed mucosa of patients with IBDs by means of quantitative RT-PCR and immunohistochemistry. Peripheral blood CD4+ T cells were transfected with lentivirus-expressing TRIM21 (LV-TRIM21) or LV-sh-TRIM21, and cytokine expression was determined by using quantitative RT-PCR and ELISA. TRIM21-/- mice were generated, and trinitrobenzene sulfonic acid- and CD45RBhighCD4+ T cell-induced colitis models were established to determine its role in induction of intestinal inflammation. TRIM21 was expressed predominantly in CD4+ T cells and decreased markedly in the inflamed mucosa of patients with IBDs compared with healthy control subjects. Ectopic expression of TRIM21 inhibited IBD CD4+ T cells to differentiate into TH1 and TH17cells, whereas downregulation of TRIM21 had the opposite effects. TRIM21-/- mice had more severe colitis after administration of trinitrobenzene sulfonic acid compared with wild-type mice, which was characterized by increased expression of IFN-γ, TNF-α, and IL-17A in the colon. TRIM21-/-CD45RBhighCD4+ T cells reconstituted into recombination-activating gene (Rag1)-/- mice induced more severe colitis than in wild-type control mice. Mechanistically, interferon regulatory factor 3 was identified as a functional downstream target of TRIM21 in that silencing of interferon regulatory factor 3 suppressed TRIM21-/-CD4+ T-cell differentiation into TH1 and TH17cells. TRIM21 plays a protective role in mucosal inflammation through inhibiting TH1 and TH17cell differentiation. Thus TRIM21 might serve as a potential therapeutic target for the treatment of IBDs.

Bacteroides fragilis Enterotoxin Induces Formation of Autophagosomes in Endothelial Cells but Interferes with Fusion with Lysosomes for Complete Autophagic Flux through a Mitogen-Activated Protein Kinase-, AP-1-, and C/EBP Homologous Protein-Dependent Pathway

Bacteroides fragilis enterotoxin (BFT), a virulence factor of enterotoxigenic B. fragilis (ETBF), plays an essential role in mucosal inflammation. Although autophagy contributes to the pathogenesis of diverse infectious diseases, little is known about autophagy in ETBF infection. This study was conducted to investigate the role of BFT in the autophagic process in endothelial cells (ECs). Stimulation of human umbilical vein ECs (HUVECs) with BFT increased light chain 3 protein II (LC3-II) conversion from LC3-I and protein expression of p62, Atg5, and Atg12. In addition, BFT-exposed ECs showed increased indices of autophagosomal fusion with lysosomes such as LC3-lysosome-associated protein 2 (LAMP2) colocalization and the percentage of red vesicles monitored by the expression of dual-tagged LC3B. BFT also upregulated expression of C/EBP homologous protein (CHOP), and inhibition of CHOP significantly increased indices of autophagosomal fusion with lysosomes. BFT activated an AP-1 transcription factor, in which suppression of AP-1 activity significantly downregulated CHOP and augmented autophagosomal fusion with lysosomes. Furthermore, suppression of Jun N-terminal protein kinase (JNK) mitogen-activated protein kinase (MAPK) significantly inhibited the AP-1 and CHOP signals, leading to an increase in autophagosomal fusion with lysosomes in BFT-stimulated ECs. These results suggest that BFT induced accumulation of autophagosomes in ECs, but activation of a signaling pathway involving JNK, AP-1, and CHOP may interfere with complete autophagy.

Potential role of mucosal inflammation and histone modifications in alcohol-mediated promotion of colonic tumorigenesis in mice

Potential role of mucosal inflammation and histone modifications in alcohol-mediated promotion of colonic tumorigenesis in mice

Proteomic Analysis in Esophageal Eosinophilia Reveals Differential Galectin-3 Expression and S-Nitrosylation

Background Aims: Esophageal eosinophilia (EE) can be caused by gastroesophageal reflux disease (GERD), proton-pump inhibitor-responsive EE (PPI-REE) or eosinophilic esophagitis (EoE). This study quantified protein expression and S-nitrosylation (SNO) post-translational modifications in EE to elucidate potential disease biomarkers. Methods: Proximal and distal esophageal (DE) biopsy proteins in patients with EE and in controls were assayed for protein content and fluorescence-labeled with and without ascorbate treatment. Protein SNO was determined, and selected protein spots were identified by matrix-assisted laser desorption ionization time-of-flight/mass spectrometry. Western blot and ingenuity pathway analysis were performed. Results: Ninety-one of 648 proteins showed differential expression. There were significantly altered levels of abundance for 11 proximal and 14 DE proteins. Hierarchal clustering revealed differential SNO in inflamed tissues, indicating reactive nitrogen/oxygen species involvement. Galectin-3 was upregulated in both proximal (p < 0.04) and distal (p < 0.004) esophageal EE biopsies compared to controls. In distal EE samples, galectin-3 was significantly S-nitrosylated (p < 0.004). Principal component analysis revealed sample group discrimination distally. Conclusion: Proteomic analysis in EE esophageal mucosa revealed a distinct abundance and nitrosylation profile, most prominently in distal biopsies. Galectin-3 was upregulated in expression and SNO, which may indicate its potential role in mucosal inflammation. These results call for more studies to be performed to investigate the role of galectin-3 in GERD, PPI-REE and EoE.

TRPM8 on mucosal sensory nerves regulates colitogenic responses by innate immune cells via CGRP.

TRPM8 is the molecular sensor for cold; however, the physiological role of TRPM8+ neurons at mucosal surfaces is unclear. Here we evaluated the distribution and peptidergic properties of TRPM8+ fibers in naïve and inflamed colons, as well as their role in mucosal inflammation. We found that Trpm8−/− mice were hypersusceptible to DSS-induced colitis, and that Trpm8−/− CD11c+ DCs showed hyperinflammatory responses to TLR stimulation. This was phenocopied in CGRP receptor deficient, but not in substance P receptor deficient mice, suggesting a functional link between TRPM8 and CGRP. The DSS phenotype of CGRP receptor deficient mice could be adoptively transferred to WT mice, suggesting that CGRP suppresses the colitogenic activity of bone marrow-derived cells. TRPM8+ mucosal fibers expressed CGRP in human and mouse colon. Furthermore, neuronal CGRP contents were increased in colons from naïve and DSS treated Trpm8−/− mice, suggesting deficient CGRP release in the absence of TRPM8 triggering. Finally, treatment of Trpm8−/− mice with CGRP reversed their hyperinflammatory phenotype. These results suggest that TRPM8 signaling in mucosal sensory neurons is indispensable for the regulation of innate inflammatory responses via the neuropeptide CGRP.

Tachykinin peptide, substance P, and its receptor NK-1R play an important role in alimentary tract mucosal inflammation during cytotoxic therapy.

The alimentary tract mucosal inflammation has been a topic of concern in oncology; though many modalities of treatment have been proposed for mucosal inflammation, the contributing adverse effects have severely affected the quality of life of patients. This review focuses on the importance of neurogenic peptide, Substance P and its receptor NK-1R in modulating the cascades of events in mucosal inflammation during cytotoxic therapy. There are various preclinical and clinical models showing increased expression of Substance P/NK-1R in ionizing radiation and chemotherapy, but only very few preclinical studies to our knowledge have highlighted or examined its role in mucosal inflammation. Hence, the importance of neuropeptide involved in the inflammatory events in mucosal inflammation in cytotoxic therapy could be a major breakthrough for future research purposes and treatment. The factors contributing to the severity of tissue reactions have been multietiogenic; thus, resultant treatment also has to be directed toward multiple contributing factors. This review also focuses on the significance of care strategy to be adopted in alimentary tract mucositis when multietiogenic factors are taken into consideration.

Bacteroides fragilis enterotoxin upregulates lipocalin-2 expression in intestinal epithelial cells

Enterotoxigenic Bacteroides fragilis (ETBF) produces an ∼20 kDa B. fragilis enterotoxin (BFT), which plays an essential role in mucosal inflammation. Lipocalin (Lcn)-2, a siderophore-binding antimicrobial protein, is critical for control of bacterial infection; however, expression of Lcn-2 in BFT-exposed intestinal epithelial cells has not been elucidated. In the present study, stimulation of human intestinal epithelial cells with BFT resulted in the upregulation of Lcn-2 expression that was a relatively late response of intestinal epithelial cells compared with human β-defensin (hBD)-2 expression. The upregulation of Lcn-2 was dependent on AP-1 but not on NF-κB signaling. Lcn-2 induction via AP-1 was regulated by mitogen-activated protein kinases (MAPKs) including ERK and p38. Lcn-2 was secreted from the apical and basolateral surfaces in BFT-treated cells. These results suggest that a signaling pathway involving MAPKs and AP-1 is required for Lcn-2 induction in intestinal epithelial cells exposed to BFT, after which the secreted Lcn-2 may facilitate antimicrobial activity within ETBF-infected mucosa.

A novel role for the Rho-associated kinase, ROCK, in IL-1-stimulated intestinal epithelial cell responses

Intestinal epithelial cells (IEC) play a role in mucosal inflammation by producing pro-inflammatory chemokines that may initiate or amplify local responses. IL-1 is a potent activator of IEC and its receptor localizes to focal adhesions. Since the Rho-associated kinase, ROCK, also localizes to focal adhesions, we examined the role of ROCK in IL-1-induced chemokine responses in IEC cell lines. Suppressing ROCK with the Y27632 inhibitor suppressed IL-1-stimulated Caco-2 cell CXCL8/IL-8 and IEC-6 cell CCL2/MCP-1 secretion and mRNA levels. ROCK inhibition also suppressed IL-1-induced JNK phosphorylation in both cell lines, but high levels of the inhibitor had no significant effect on IL-1-stimulated Caco-2 IκBα phosphorylation and degradation or IKK phosphorylation and kinase activity. Therefore, ROCK may exert an effect on IL-1-stimulated JNK signaling to AP-1 activation, with little effect on IKK/IκBα signaling, defining a potentially important mechanism for regulating IL-1 signaling in IEC that may be essential for optimal cytokine responses.

Cellular methylation plays an anti-inflammatory role in Mucosal Inflammation

The inflammatory bowel diseases (IBD), including both Crohn's disease and ulcerative colitis, are debilitating diseases of unknown etiology. Intestinal epithelial cells are a crucial cell type in the maintenance of colonic tissue homeostasis and IBD is characterized by a breakdown of the intestinal epithelial barrier leading to increased exposure of the mucosal immune system to antigenic luminal material. It is now appreciated that inflammatory responses in IBD are accompanied by striking shifts in tissue metabolism. These shifts result, at least in part, from perturbation of the vasculature leading to the decreased supply of oxygen and nutrients. IBD almost certainly elicits changes in a number of cellular metabolic pathways, however, the metabolic shifts induced in the colonic epithelia during the inflammatory process have not been elucidated in a systematic manner. Here we examined global metabolic consequences of mucosal inflammation employing both in vitro and in vivo models of disease. Initial analysis of the metabolic signature elicited by inflammation in epithelial models and in colonic tissue isolated from murine colitis demonstrated that levels of specific metabolites associated with cellular methylation reactions are significantly altered by model inflammatory systems. Furthermore, expression of enzymes central to all cellular methylation, SAM synthetase and SAH hydrolase, are increased in response to inflammation. Subsequent studies showed that DNA methylation is substantially increased during inflammation and that epithelial NF-kB activity is significantly inhibited following treatment with a reversible SAH hydrolase inhibitor, DZ2002. Finally, these studies demonstrated that inhibition of cellular methylation in a murine model of colitis results in disease exacerbation while administration of a methyl donor ameliorated disease. Taken together, these studies provide a new and compelling role for methylation as an endogenously protective mechanism for mucosal inflammation. Additionally, the findings herein provide tractable and potentially new therapeutic opportunities for methylation-dependent targets in mucosal diseases such as IBD.

Bacteroides fragilis Enterotoxin Upregulates Intercellular Adhesion Molecule-1 in Endothelial Cells via an Aldose Reductase-, MAPK-, and NF-κB–Dependent Pathway, Leading to Monocyte Adhesion to Endothelial Cells

Enterotoxigenic Bacteroides fragilis (ETBF) produces a ∼ 20-kDa heat-labile enterotoxin (BFT) that plays an essential role in mucosal inflammation. Although a variety of inflammatory cells is found at ETBF-infected sites, little is known about leukocyte adhesion in response to BFT stimulation. We investigated whether BFT affected the expression of ICAM-1 and monocytic adhesion to endothelial cells (ECs). Stimulation of HUVECs and rat aortic ECs with BFT resulted in the induction of ICAM-1 expression. Upregulation of ICAM-1 was dependent on the activation of IκB kinase (IKK) and NF-κB signaling. In contrast, suppression of AP-1 did not affect ICAM-1 expression in BFT-stimulated cells. Suppression of NF-κB activity in HUVECs significantly reduced monocytic adhesion, indicating that ICAM-1 expression is indispensable for BFT-induced adhesion of monocytes to the endothelium. Inhibition of JNK resulted in a significant attenuation of BFT-induced ICAM-1 expression in ECs. Moreover, inhibition of aldose reductase significantly reduced JNK-dependent IKK/NF-κB activation, ICAM-1 expression, and adhesion of monocytes to HUVECs. These results suggest that a signaling pathway involving aldose reductase, JNK, IKK, and NF-κB is required for ICAM-1 induction in ECs exposed to BFT, and may be involved in the leukocyte-adhesion cascade following infection with ETBF.

Expression of GH/IGF-1 Axis Compounds in Moderate-Severe Crohn's Disease: Role of Mucosal Inflammation and Anti TNF-α Treatment

AIM: Growth failure in children and adolescents, weight loss and catabolism in adults, are well known features of active Crohn's disease (CD). Increasing evidence shows that these features may be due to growth hormone (GH) resistance caused by persistent chronic inflammation. Aim of this study was to evaluate, in CD patients, a possible peripheral GHresistance (intestinal mucosa), and eventual modifications following anti TNF-α treatment. MATERIALS AND METHODS: 9 patients (5 F, median age 42.2 years, range 19-67) with moderate-severe active CD (CDAI>220), consecutively scheduled to receive three infliximab infusions at a dose of 5 mg/kg for induction of remission, were studied. Biopsy specimens from normal appearing duodenal mucosa were collected, in the 2 weeks prior to the first and after the third infusion. Confocal and real time PCR analysis of insulin-like growth factor 1 (IGF-1), activated signal transducer and activator of transcription protein 5 (phosphoSTAT5) and suppressor of cytokine signalling protein 3 (SOCS-3) were carried out and normalised to GAP, 18S and H3 referring genes. Four dyspeptic patients (2 F, median age 39 years, range 24-57), who underwent upper endoscopy with duodenal biopsy sampling, represented our control group. Differences between CD patients and controls were analysed by one-way ANOVA and REST-coupled ANOVA analysis. RESULTS: In CD patients, a significant inverse correlation was found when comparing phospho-STAT5 levels with CDAI (r=-0.71; p=0.003). Confocal analysis showed a significant decrease in phospho-STAT5 immunoreactivity in sections from CD patients, compared to controls (p<0.001). After treatment, phospho-STAT5 levels significantly increased (p<0.001). Molecular data for phospho-STAT5 were in keeping with biochemical findings. At baseline, compared with controls, in CD patients, the PCR analysis of IGF-1, showed a trend towards a decrease, while SOCS3 showed a trend towards an increase. Following treatment, SOCS-3 and IGF-1 target genes showed a trend toward a decrease and an increase, respectively. Nevertheless, following infliximab induction treatment, IGF-1, phospho-STAT5 and SOCS-3 levels did not reach those of the control group. CONCLUSION: The present study underline the effect of inflammation on the growth hormone axis not only at the level of hepatic metabolism, but also in the intestinal mucosa, since biologic agents able to inhibit pro-inflammatory cytokines, in particular TNF-α, the main inflammatory mediator, reverse growth hormone resistance. These therapeutic approaches could prevent the onset of those clinical conditions with a negative impact on child growth and quality of life of adults.