Enhanced mucosal cytokine production in inflammatory bowel disease

Subclinical Pulmonary Involvement in Active IBD Responds to Biologic Therapy

OBJECTIVE

Increased mortality from respiratory diseases was observed in epidemiological studies of patients with ulcerative colitis [UC] as a potentially underestimated extraintestinal manifestation. We therefore investigated the presence of pulmonary manifestations of inflammatory bowel disease [IBD] and the potential effect of tumour necrosis factor alpha [TNF-α] inhibitors on pulmonary function tests [PFT] in a prospective, longitudinal study.

METHODS

In all, 92 consecutive patients with IBD (49 Crohn´s disease [CD], 43 UC) and 20 healthy controls were recruited. Fifty patients with IBD were in remission, and 42 had active disease with 22 of these being examined before and 6 weeks after initiating anti-TNF therapy. Pulmonary function tests [PFT] were evaluated using the Medical Research Council [MRC] dyspnoea index and a standardized body plethysmography. IBD activity was assessed using Harvey-Bradshaw index for CD and partial Mayo score for UC. Data are presented as mean ± standard error of the mean [SEM].

RESULTS

Patients with active IBD showed significant reduction of PFT. Forced expiration [Tiffeneau index] values [FEV1%] were significantly reduced in IBD patients with active disease [78.8 ± 1.1] compared with remission [86.1 ± 0.9; p = 0.0002] and with controls [87.3 ± 1.3; p = 0.001]. Treatment with anti-TNF induced a significant relief in obstruction [p = 0.003 for FEV1% in comparison with baseline levels]. The level of pulmonary obstruction significantly correlated with clinical inflammation scores [HBI or Mayo].

CONCLUSIONS: PATIENTS

with active IBD present with significant obstructive abnormalities in their PFTs. Obstruction is related to inflammatory activity, with anti-TNF improving PFTs. Pulmonary obstruction and possibly chronic bronchopulmonary inflammation is an overlooked problem in active IBD that is probably obscured by intestinal symptoms.

Magnesium isoglycyrrhizinate suppresses LPS-induced inflammation and oxidative stress through inhibiting NF-κB and MAPK pathways in RAW264.7 cells

Magnesium Isoglycyrrhizinate (MgIG), a novel molecular compound extracted from licorice root, has exhibited greater anti-inflammatory activity and hepatic protection than glycyrrhizin and β-glycyrrhizic acid. In this study, we investigated the anti-inflammatory effect and the potential mechanism of MgIG on Lipopolysaccharide (LPS)-treated RAW264.7 cells. MgIG down-regulated LPS-induced pro-inflammatory mediators and enzymes in LPS-treated RAW264.7 cells, including TNF-α, IL-6, IL-1β, IL-8, NO and iNOS. The generation of reactive oxygen species (ROS) in LPS-treated RAW264.7 cells was also reduced. MgIG attenuated NF-κB translocation by inhibiting IKK phosphorylation and IκB-α degradation. Simultaneously, MgIG also inhibited LPS-induced activation of MAPKs, including p38, JNK and ERK1/2. Taken together, these results suggest that MgIG suppresses inflammation by blocking NF-κB and MAPK signaling pathways, and down-regulates ROS generation and inflammatory mediators.

Anti-inflammatory effect of a standardized triterpenoid-rich fraction isolated from Rubus coreanus on dextran sodium sulfate-induced acute colitis in mice and LPS-induced macrophages

ETHNOPHARMACOLOGICAL RELEVANCE

Rubus coreanus Miquel (Rosaceae), the Korean black raspberry, has traditionally been used to treat inflammatory diseases including diarrhea, asthma, stomach ailment, and cancer. Although previous studies showed that the 19α-hydroxyursane-type triterpenoids isolated from Rubus coreanus exerted anti-inflammatory activities, their effects on ulcerative colitis and mode of action have not been explored. This study was designed to assess the anti-inflammatory effects and the molecular mechanisms involving19α-hydroxyursane-type triterpenoid-rich fraction from Rubus coreanus (TFRC) on a mice model of colitis and lipopolysaccharide (LPS)-induced RAW 264.7 macrophages.

MATERIALS AND METHODS

Experimental colitis was induced by DSS for 7 days in ICR mice. Disease activity indices (DAI) took into account body weight, stool consistency, and gross bleeding. Histological changes and macrophage accumulation were observed by immunohistochemical analysis. Pro-inflammatory markers were determined using immunoassays, RT-PCR, and real time PCR. Signaling pathway involving nuclear factor-κB (NF-κB) and mitogen-activated protein kinases (MAPKs) activation was determined by luciferase assay and Western blotting.

RESULTS

In DSS-induced colitis mice, TFRC improved DAIs and pathological characteristics including colon shortening and colonic epithelium injury. TFRC suppressed tissue levels of pro-inflammatory cytokines and reduced macrophage infiltration into colonic tissues. In LPS-induced RAW 264.7 macrophages, TFRC inhibited the production of NO, PGE2, and pro-inflammatory cytokines by down-regulating the activation of NF-κB and p38 MAPK signaling.

CONCLUSION

The study demonstrates that TFRC has potent anti-inflammatory effects on DSS-induced colonic injury and LPS-induced macrophage activation, and supports its possible therapeutic and preventive roles in colitis.

Not all monoclonals are created equal - lessons from failed drug trials in Crohn's disease

The recent success of the anti-integrin antibody Vedolizumab can barely conceal the fact that the biologics armamentarium in Crohn's disease has barely evolved beyond TNF blockers so far. This contrasts with other immune-related diseases considered mechanistically and genetically closely related, such as psoriasis and rheumatoid arthritis, where approved biologics target a variety of independent biological mechanisms. Several pharmacological assets that entered clinical development have proven ineffective, or less effective than originally anticipated. While blockade of IL-17A and its receptor via Secukinumab and Brodalumab, respectively, worsened Crohn's disease, the beneficial effect of IL-12/23 p40 blockade via Ustekinumab appeared confined to a subpopulation of Crohn's disease patients who have previously failed on TNF blockers. Clinical development of the IFNγ blocker Fontolizumab was stopped despite demonstrating some clinical benefit, while the T cell co-stimulation blocker Abatacept did not exhibit any hint towards efficacy in Crohn's disease. Here I review results from these individual development programmes, and also reflect on the lack of efficacy of the TNF blocker Etanercept. I will discuss aspects of individual trials that might have confounded their interpretation and highlight the evolution in primary and secondary endpoints that have contributed to increasing robustness of results obtained in recent years. Finally, I suggest that mechanistic studies in murine genetic models combined with exploratory immunological studies incorporated in early drug development may represent the key for identifying the next generation of successful pharmacological targets in Crohn's disease.

Myosin light chain kinase expression induced via tumor necrosis factor receptor 2 signaling in the epithelial cells regulates the development of colitis-associated carcinogenesis

It has been suggested that prolonged inflammatory bowel diseases (IBD) may lead to colitis-associated carcinogenesis (CAC). We previously observed that the NF-κB activation in colonic epithelial cells is associated with increased tumor necrosis factor receptor 2 (TNFR2) expression in CAC development. However, the mechanism by which epithelial NF-κB activation leading to CAC is still unclear. Myosin light chain kinase (MLCK) has been reported to be responsible for the epithelial permeability associated with TNF signaling. Therefore we focused on the role of MLCK expression via TNFR2 signaling on CAC development. Pro-tumorigenic cytokines such as IL-1β, IL-6 and MIP-2 production as well as INF-γ and TNF production at the lamina propria were increased in the setting of colitis, and further in tumor tissues in associations with up-regulated TNFR2 and MLCK expressions in the epithelial cells of a CAC model. The up-regulated MLCK expression was observed in TNF-stimulated colonic epithelial cells in a dose-dependent fashion in association with up-regulation of TNFR2. Silencing TNFR2, but not TNFR1, resulted in restoration of epithelial tight junction (TJ) associated with decreased MLCK expression. Antibody-mediated blockade of TNF signaling also resulted in restoration of TJ in association with suppressed MLCK expression, and interestingly, similar results were observed with suppressing TNFR2 and MLCK expressions by inhibiting MLCK in the epithelial cells. Silencing of MLCK also resulted in suppressed TNFR2, but not TNFR1, expression, suggesting that the restored TJ leads to reduced TNFR2 signaling. Such suppression of MLCK as well as blockade of TNFR2 signaling resulted in restored TJ, decreased pro-tumorigenic cytokines and reduced CAC development. These results suggest that MLCK may be a potential target for the prevention of IBD-associated tumor development.

Sodium 4-phenylbutyrate suppresses the development of dextran sulfate sodium-induced colitis in mice

Sodium 4-phenylbutyrate (PBA) exhibits anti-inflammatory effects by suppressing nuclear factor-κB (NF-κB) activation. In the present study, the effects of PBA on a mouse model of dextran sulfate sodium (DSS)-induced colitis were investigated. The therapeutic efficacy of PBA (150 mg/kg body weight) in DSS-induced colitis was assessed based on the disease activity index (DAI), colon length, the production of inflammatory cytokines and histopathological examination. The results showed an increase in the median survival time in the PBA-treated group compared with that of the untreated DSS control group. DAI scores were lower in the PBA-treated group than in the DSS control group during the 12 days of the experiment. Additionally, PBA treatment inhibited shortening of the colon and the production of the inflammatory cytokines tumor necrosis factor-α, interleukin-1β and IL-6, which were measured in the colonic lavage fluids. Histopathological examination of the DSS control group showed diffused clusters of chronic inflammatory cells infiltrating the lamina propria, partial exfoliation of the surface epithelium and decreased numbers of mature goblet cells. By contrast, in the PBA-treated group the histopathological findings were the same as those of the normal healthy controls. These results suggest that PBA strongly prevents DSS-induced colitis by suppressing the mechanisms involved in its pathogenesis.

Intestinal anti-inflammatory activity of lentinan: influence on IL-8 and TNFR1 expression in intestinal epithelial cells

Inflammatory bowel disease (IBD) is characterized by chronic inflammation of the gastrointestinal tract. It is unknown whether β-1,3;1,6-glucan can induce immune suppressive effects. Here, we study intestinal anti-inflammatory activity of Lentinula edodes-derived β-1,3;1,6-glucan, which is known as lentinan. Dextran sulfate sodium (DSS)-induced colitis mice were used to elucidate effects of lentinan in vivo. In the cellular level assessment, lentinan was added into a co-culture model consisting of intestinal epithelial Caco-2 cells and LPS-stimulated macrophage RAW264.7 cells. Ligated intestinal loop assay was performed for assessing effects of lentinan on intestinal epithelial cells (IECs) in vivo. Oral administration of lentinan (100 µg/mouse) significantly ameliorated DSS-induced colitis in body weight loss, shortening of colon lengths, histological score, and inflammatory cytokine mRNA expression in inflamed tissues. Lentinan reduced interleukin (IL)-8 mRNA expression and nuclear factor (NF)-κB activation in Caco-2 cells without decreasing of tumor necrosis factor (TNF)-α production from RAW264.7 cells. Flow cytometric analysis revealed that surface levels of TNF receptor (TNFR) 1 were decreased by lentinan treatment. A clathrin-mediated endocytosis inhibitor, monodansylcadaverine, canceled lentinan inhibition of IL-8 mRNA expression. Moreover, lentinan inhibited TNFR1 expression in Caco-2 cells in both protein and mRNA level. Lentinan also inhibited TNFR1 mRNA expression in mouse IECs. These results suggest that lentinan exhibits intestinal anti-inflammatory activity through inhibition of IL-8 mRNA expression associated with the inhibition of NF-κB activation which is triggered by TNFR1 endocytosis and lowering of their expression in IECs. Lentinan may be effective for the treatment of gut inflammation including IBD.

Bone cells from patients with quiescent Crohn's disease show a reduced growth potential and an impeded maturation

Patients with Crohn's disease (CD) are at increased risk of developing osteoporosis. The mechanism underlying bone loss in CD patients is only partly understood. Inflammation is thought to contribute by causing a disturbed bone remodeling. In this study, we aimed to compare functional characteristics of osteoblasts from CD patients and controls, as osteoblasts are one of the effector cells in bone remodeling. The study included 18 patients with quiescent CD and 18 healthy controls. Bone cells obtained from iliac crest biopsies were cultured in the absence and presence of the inflammatory cytokines IL-1α, IL-1β, IL-6, TNF-α, IL-10, and TGF-β. At various time points, cell proliferation and differentiation were analyzed. Bone cells from CD patients showed a prolonged culture period to reach confluence and a decreased cell number at confluence. CD patient-derived bone cell cultures produced higher alkaline phosphatase levels, whereas osteocalcin levels were considerably reduced compared to control cultures. At the proliferation level, the responsiveness to inflammatory cytokines was similar in bone cells from CD patients and controls. At the differentiation level, CD cultures showed an increased responsiveness to IL-6 and a decreased responsiveness to TGF-β. Responsiveness to the other cytokines tested was unaffected. In summary, we show a reduced growth potential and impeded maturation of bone cells from quiescent CD patients in vitro. These disease-related alterations combined with an unchanged sensitivity of CD patient-derived bone cells to inflammatory cytokines, provide a new insight in the understanding of CD-associated bone loss.

Orally administered aqueous extract of Inonotus obliquus ameliorates acute inflammation in dextran sulfate sodium (DSS)-induced colitis in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Chaga mushroom (Inonotus obliquus) has been used in folk medicine to treat several disorders through its various biological functions. I. obliquus is claimed to produce general immune-potentiating and strengthening, antiinflammatory, and antitumor properties, but its effects on intestinal inflammation (ulcerative colitis) are clearly not understood.

AIM OF THE STUDY

To determine the effects and mode of action of an aqueous extract of I. obliquus (IOAE) on experimental colitis in mice induced by dextran sulfate sodium (DSS).

MATERIALS AND METHODS

Female 5-week-C57BL/6 mice were randomized into groups differing in treatment conditions (prevention and treatment) and doses of IOAE (50 and 100mg/kg body weight). Mice were exposed to DSS (2%) in their drinking water over 7 day to induce acute intestinal inflammation. In colon tissues, we evaluated histological changes by hematoxylin and eosin staining, levels of iNOS by immuno-histochemical staining, and neutrophil influx by myeloperoxidase assay. mRNA expression of pro-inflammatory mediators TNF-α, IL-1β, IL-6, and IFN-γ was determined by RT-PCR.

RESULTS

Histological examinations indicated that IOAE suppressed edema, mucosal damage, and the loss of crypts induced by DSS. IOAE markedly attenuated DSS-induced iNOS levels and myeloperoxidase accumulation in colon tissues, demonstrating its suppressive effect on infiltration of immune cells. In addition, IOAE significantly inhibited mRNA expression of pro-inflammatory cytokines induced by DSS in colon tissues.

CONCLUSION

Our results suggest anti-inflammatory effect of IOAE at colorectal sites due to down-regulation of the expression of inflammatory mediators. Suppression of TNF-α and iNOS together with IL-1β by IOAE denotes that it might be a useful supplement in the setting of inflammatory bowel disease.

The role of cytokines in inflammatory bowel disease

Cytokines play an important role in the development and persistence of the inflammatory lesions seen in Crohn's disease and ulcerative colitis. This review discusses the current thinking of the role of cytokines in chronic intestinal inflammation including the involvement of immunoregulatory cytokines within the Th1 and Th2 subsets.

Intrarectal administration of mCRAMP-encoding plasmid reverses exacerbated colitis in Cnlp(-/-) mice

Cathelicidin is a pleiotropic host defense peptide secreted by epithelial and immune cells. Whether endogenous cathelicidin is protective against ulcerative colitis, however, is unclear. Here we sought to delineate the role of endogenous murine cathelicidin (mCRAMP) and the therapeutic efficacy of intrarectal administration of mCRAMP-encoding plasmid in ulcerative colitis using dextran sulfate sodium (DSS)-challenged cathelicidin-knockout (Cnlp(-/-)) mice as a model. Cnlp(-/-) mice had more severe symptoms and mucosal disruption than the wild-type mice in response to DSS challenge. The tissue levels of interleukin-1β and tumor necrosis factor-α, myeloperoxidase activity and the number of apoptotic cells were increased in the colon of DSS-challenged Cnlp(-/-) mice. Moreover, mucus secretion and mucin gene expression were impaired in Cnlp(-/-) mice. All these abnormalities were reversed by the intrarectal administration of mCRAMP or mCRAMP-encoding plasmid. Taken together, endogenous cathelicidin may protect against ulcerative colitis through modulation of inflammation and mucus secretion.

Gastrointestinal lymphatics in health and disease

Lymphatics perform essential transport and immune regulatory functions to maintain homeostasis in the gastrointestinal (GI) system. Although blood and lymphatic vessels function as parallel and integrated systems, our understanding of lymphatic structure, regulation and functioning lags far behind that of the blood vascular system. This chapter reviews lymphatic flow, differences in lymphangiogenic and hemangiogenic factors, lymphatic fate determinants and structural features, and examines how altered molecular signaling influences lymphatic function in organs of the GI system. Innate errors in lymphatic development frequently disturb GI functioning and physiology. Expansion of lymphatics, a prominent feature of GI inflammation, may also play an important role in tissue restitution following injury. Destruction or dysregulation of lymphatics, following injury, surgery or chronic inflammation also exacerbates GI disease activity. Understanding the physiological roles played by GI lymphatics is essential to elucidating their underlying contributions to forms of congenital and acquired forms of GI pathology, and will provide novel approaches for therapy.

Anti-inflammatory effects of methanol extract of Patrinia scabiosaefolia in mice with ulcerative colitis

ETHNOPHARMACOLOGICAL RELEVANCE

Patrinia scabiosaefolia Fisch is used in folk medicines to treat intestinal abscesses, acute appendicitis, and dysentery in Asia. Although recent reports indicate that Patrinia scabiosaefolia has sedative and anti-tumor effects, its effects on ulcerative colitis have not been previously explored.

AIM OF THE STUDY

To determine the effects and the mode of action of the methanol extract of the roots of Patrinia scabiosaefolia (PME) on a model of colitis in mice induced by dextran sulfate sodium (DSS).

MATERIALS AND METHODS

We induced colitis using DSS in 5-week-ICR mice over 7 days and estimated disease activity index (DAI), which took into account body weight, stool consistency, gross bleeding, and tissue myeloperoxidase (MPO) accumulation. Colon lengths and spleen weights were measured. Histological changes were observed by H&E staining. Pro-inflammatory mediators, namely, nitric oxide (NO), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6), were determined using Griess assays, immunoassays, and by quantitative real-time reverse-transcriptase polymerase chain reaction (qRT-PCR), respectively.

RESULTS

PME significantly attenuated DSS-induced DAI scores and tissue MPO accumulation, which implied that it suppressed weight loss, diarrhea, gross bleeding, and the infiltrations of immune cells. PME administration also effectively and dose-dependently prevented shortening of colon length and enlargement of spleen size. Histological examinations indicated that PME suppressed edema, mucosal damage, and the loss of crypts induced by DSS. Furthermore, PME inhibited the abnormal secretions and mRNA expressions of pro-inflammatory cytokines, such as, TNF-α, IL-1β, and IL-6.

CONCLUSION

These results suggest that PME has an anti-inflammatory effect at colorectal sites that is due to the down-regulations of the productions and expressions of inflammatory mediators, and that it may have therapeutic value in the setting of inflammatory bowel disease (IBD).

Embelin ameliorates dextran sodium sulfate-induced colitis in mice

Embelin has been used to treat fever, inflammatory diseases, and a variety of gastrointestinal ailments for thousands of years. Although reports indicate that embelin has anti-inflammatory and anti-tumor effects, its effects on ulcerative colitis have not been previously explored. The purpose of the present work was to evaluate the anti-inflammatory effect of embelin on dextran sulfate sodium (DSS)-induced colitis. Experimental colitis was induced in BALB/c mice by dissolving 5% DSS in their drinking water for 7days. Embelin (10, 30 or 50mg/kg body weight) was administrated daily per oral route for 7days. Embelin significantly attenuated DSS-induced DAI scores and tissue MPO accumulation, which implied that it suppressed weight loss, diarrhea, gross bleeding, and the infiltrations of immune cells. Embelin administration also effectively and dose-dependently prevented shortening of colon length and enlargement of spleen size. Histological examinations indicated that embelin suppressed edema, mucosal damage, and the loss of crypts induced by DSS. Furthermore, embelin inhibited the abnormal secretions and mRNA expressions of pro-inflammatory cytokines, such as, TNF-α, IL-1β, and IL-6. These results suggest that embelin has an anti-inflammatory effect at colorectal sites that is due to the down-regulations of the productions and expressions of inflammatory mediators, and that it may have therapeutic value in the setting of inflammatory bowel disease (IBD).

The multifaceted effects of granulocyte colony-stimulating factor in immunomodulation and potential roles in intestinal immune homeostasis

The three colony-stimulating factors, granulocyte/macrophage colony-stimulating factor (GM-CSF), macrophage colony-stimulating factor (M-CSF), and granulocyte colony-stimulating factor (G-CSF), have been regarded as immunostimulators because of their role in granulocyte and myeloid hematopoiesis and immune function. However, unlike GM-CSF and M-CSF, G-CSF possesses immunosuppressive effects on other immune cells including monocytes/macrophages, dendritic cells, and T lymphocytes when exogenously administered. Given the immunomodulatory effects of exogenous G-CSF, endogenous G-CSF may also play an important role in maintaining local immune homeostasis in tissue in which it is highly and constitutively produced. This review highlights the potential role of G-CSF in immunomodulation and intestinal immune homeostasis.

Emerging roles of lymphatics in inflammatory bowel disease

The mobilization and recruitment of blood and lymphatic vasculatures are widely described in inflammatory bowel diseases (IBDs). Although angiogenesis contributes to intense gut inflammation, it remains unclear whether and when lymphangiogenesis amplifies or protects in IBD. The prolonged maintenance of lymphatic (over blood vessels) in inflammation indicates that lymphatic-blood vessel interactions may regulate IBD pathogenesis and restitution. Although lymphatic expansion helps to restore fluid balance and clear cytokines and immune cells, lymphatic failure results in accumulation of these factors and exacerbates IBD. Lymphatic obstruction and remodeling may impair lymphatic pumping, leading to repeated rounds of lymphangiogenesis. Early descriptions of Crohn's disease and ulcerative colitis describe colon lymphatic congestion, remodeling, expansion, and many other features that are recapitulated in experimental IBD and also by intestinal lymphatic obstruction, supporting lymphangitis as a cause and consequence of IBD. Growth factors, cytokines, gut flora, Toll receptors, and leukocytes all regulate inflammation and gut lymphatic remodeling in IBD. This review summarizes the importance of lymphatics and lymphangiogenesis in IBD etiology that may be useful in diagnosis and therapy of gut inflammation.

Aspectos epidemiológicos das doenças intestinais inflamatórias na macrorregião de saúde leste do Estado de Minas Gerais

A doença de Crohn e a colite ulcerativa são entidades clínicas distintas, porém relacionadas, que se incluem no grupo das doenças intestinais inflamatórias. Esse artigo trata-se de um estudo epidemiológico a fim de descrever a produção do conhecimento em doenças inflamatórias intestinais, levando em consideração os casos de internações registrados, decorrentes do agravamento da doença, nas unidades de saúde da macrorregião de saúde leste do Estado de Minas Gerais. As doenças inflamatórias intestinais são consideradas um dos grandes problemas da população moderna, uma vez que geram repercussões importantes na qualidade de vida de seus portadores, acarretando alterações no âmbito social, psicológico e profissional. Durante o período de 1998 a 2005, foram registradas 363 internações hospitalares, em função das doenças intestinais inflamatórias, distribuídas em 184 e 179 casos nos gêneros masculino e feminino, respectivamente. Em função da escassez de estudos e do número de internações na macrorregião leste do Estado de Minas Gerais, pesquisas devem ser conduzidas a fim de delinear o perfil dos pacientes portadores de doenças inflamatórias intestinais, bem como detectar as possíveis alterações biopsicossociais a fim de promover uma assistência multiprofissional, humanizada e baseada em evidências.

Orally administered glucans from the edible mushroom Pleurotus pulmonarius reduce acute inflammation in dextran sulfate sodium-induced experimental colitis

Polysaccharides are one of the most potent mushroom-derived substances exhibiting anti-inflammatory and immunomodulatory properties. The aims of the present study were to determine whether orally administered glucans from the edible mushroom Pleurotus pulmonarius could attenuate or prevent the development of experimental colitis in mice. Colonic inflammation was induced in mice by treatment with 3.5 % dextran sulfate sodium (DSS) for 18 d. Before or after DSS administration, mice were given hot water solubles (HWS) or mycelium extract (ME) (2 or 20 mg per mouse) daily in their food. Colonic damage was macroscopically and histologically evaluated. Inflammation was assessed by changes in colon length, TNF-alpha levels released by colonic samples in organ culture and myeloperoxidase (MPO) activity. mRNA levels of pro-inflammatory (IL-1beta) and anti-inflammatory (IL-10) cytokines in colonic samples were determined by quantitative real-time RT-PCR. P. pulmonarius glucans attenuated and prevented the development of symptoms associated with DSS-induced colitis. High doses of HWS and ME blocked colon shortening, suppressed MPO activity and improved macroscopic score in all treatment groups. In addition, histological damage from colitis was reduced by HWS and ME at all doses. The tissue levels of TNF-alpha protein were significantly decreased and correlated with degree of inflammation and macroscopic score. All treatments significantly attenuated the increased DSS-mediated expression levels of IL-1beta. We conclude that the different glucan preparations (HWS or ME) harvested from P. pulmonarius when orally administered to DSS-treated mice attenuate the development of colonic inflammation, suggesting putative clinical utility for these extracts in the treatment of colitis.

3,3'-diindolylmethane attenuates colonic inflammation and tumorigenesis in mice

BACKGROUND

3,3-Diindolylmethane (DIM) is a major in vivo product of acid-catalyzed oligomerization of indole-3-carbinol (I3C) derived from Brassica food plants. Although DIM is known as a chemopreventive and chemotherapeutic phytochemical, the effects of DIM on inflammation in vivo are still unknown. In the present study we investigated the antiinflammatory effects of DIM on experimental colitis and colitis-associated colorectal carcinogenesis.

METHODS

To determine if DIM has an antiinflammatory effect in vivo, we examined the therapeutic effects of DIM in dextran sodium sulfate (DSS)-induced experimental colitis and colitis-associated colon carcinogenesis induced by azoxymethane (AOM)/DSS in BALB/c mice.

RESULTS

Treatment with DIM significantly attenuated loss of body weight, shortening of the colon, and severe clinical signs in a colitis model. This was associated with a remarkable amelioration of the disruption of the colonic architecture and a significant reduction in colonic myeloperoxidase activity and production of prostaglandin E(2), nitric oxide, and proinflammatory cytokines. Further, DIM administration dramatically decreased the number of colon tumors in AOM/DSS mice.

CONCLUSIONS

These results suggest that DIM-mediated antiinflammatory action at colorectal sites may be therapeutic in the setting of inflammatory bowel disease and colitis-associated colon cancer.

Differential expression of pro-inflammatory cytokines and a pro-apoptotic protein in pelvic ileal pouches for ulcerative colitis and familial adenomatous polyposis

BACKGROUND

Pouchitis after total rectocolectomy is among the most common complications of patients with ulcerative colitis (UC). However, its frequency is quite rare in patients with familial adenomatous polyposis (FAP). We evaluated the inflammatory and pro-apoptotic activity in endoscopically normal mucosa of the ileal pouch in patients with UC and FAP.

METHODS

Twenty patients (10 with UC and 10 with FAP) with "J" pouch after total proctocolectomy were studied as were 10 normal controls. Biopsies were obtained from the mucosa of the pouch of UC and FAP patients and from the normal ileum of controls. The expression levels of TNF-alpha, IL-1beta, IL-6, IL-8 and phospho-BAD were determined by immunoblotting. Activated NFkappaB was evaluated by immuno-precipitation and immunoblotting for IkappaB kinase beta.

RESULTS

Patients with UC had higher levels of IL-1beta, IL-6, IL-8 and TNF-alpha than patients with FAP. The level of TNF-alpha was higher in patients with UC than in patients with FAP; both patient groups had TNF-alpha levels higher than controls. Activation of NFkappaB was similar in all three groups. The expression of phospho-BAD was significantly lower in patients with FAP than in patients with UC.

CONCLUSIONS

As compared with patients with FAP, patients with UC presented increased levels of some pro-inflammatory cytokines, even in the absence of clinical or endoscopic signs of pouchitis. Patients with FAP presented lower levels of pro-inflammatory proteins and of phospho-BAD. These findings may explain the higher rates of progression to pouchitis in UC patients, which could correlate with mucosal atrophy that occurs in inflamed tissue.

Impacts of long-term enteral nutrition on clinical and endoscopic disease activities and mucosal cytokines during remission in patients with Crohn's disease: a prospective study

BACKGROUND

Long-term enteral nutrition may maintain clinical and endoscopic remission in patients with Crohn's disease (CD). The aim of this prospective study was to investigate the impacts of long-term enteral nutrition on clinical and endoscopic disease activities and mucosal tissue cytokines in patients with quiescent CD.

METHODS

Forty patients with CD who achieved clinical remission were included. Of these, 20 received continuous elemental diet (Elental) infusion during the nighttime and a low-fat diet during the daytime (EN group) and 20 received neither nutritional therapy nor food restriction (non-EN group). With these regimens, all 40 patients were monitored for 1 year. Further, ileocolonoscopy was performed at entry, at 6 and 12 months, and mucosal biopsies were taken for cytokine assays.

RESULTS

On an intention-to-treat basis, 5 patients (25%) in the EN group and 13 (65%) in the non-EN group had a clinical relapse during the 1-year observation (P = 0.03). The mean endoscopic inflammation (EI) scores were not significantly different between the groups at both entry and 6 months, but at 12 months EI scores were significantly higher in the non-EN group than in the EN group (P = 0.04). Additionally, the mucosal tissue interleukin (IL)-1beta, IL-6, and tumor necrosis factor (TNF)-alpha levels significantly increased with time in the non-EN group (entry versus 12 months, IL-1beta, P = 0.02; IL-6, P = 0.002; TNF-alpha, P = 0.001). In the EN group these cytokines did not show a significant increase.

CONCLUSIONS

Long-term enteral nutrition in patients with quiescent CD has a clear suppressive effect on clinical and endoscopic disease activities and the mucosal inflammatory cytokine levels.

Inflammation is the main determinant of low bone mineral density in pediatric inflammatory bowel disease

AIMS

To assess bone mineral density (BMD) in children with Crohn's disease (CD) and ulcerative colitis (UC) and to investigate the role of inflammation and steroids on BMD.

METHODS

Lumbar spine areal BMD was measured by DXA, and volumetric BMD was then estimated (BMAD); inflammatory cytokines (TNF-alpha, IL-6, IL-10, and IL-12) were dosed in peripheral blood; and cumulative and daily doses of steroids were calculated. Therapy with infliximab (IFX) was considered for CD patients.

RESULTS

Fifty-six patients with IBD (35 CD, 21 UC) were studied. An inverse correlation was found between BMAD and IL-6 in patients with UC (r = -0.65); no correlation was found between BMAD and serum levels of TNF-alpha, IL-10, and IL-12 in all patients. Disease activity indexes use inversely correlated with BMAD (r = -0.62 in patients with CD and r = -0.64 in patients with UC). Cumulative dose of corticosteroids and duration of therapy did not correlate with BMAD. The 10 patients with CD who were treated with IFX had higher BMAD (-1 +/- 0.8) than those never treated with IFX (-1.8 +/- 0.8). Mean Pediatric Crohn's Disease Activity Index and body mass index in patients with CD (R(2) = 0.48) and IL-6 level in patients with UC (R(2) = 0.43) were found to be independent and significant predictors of BMAD.

CONCLUSIONS

In children with IBD, inflammation is an important determinant of bone loss, as shown by the correlation of BMAD with serum IL-6 and with disease activity indexes as well as by the beneficial effect of IFX on bone density. Corticosteroids seem to be a less important variable in pediatric IBD-related BMD reduction than previously believed.

Transgenic mice rich in endogenous omega-3 fatty acids are protected from colitis

Omega-6 (n-6) and omega-3 (n-3) polyunsaturated fatty acids (PUFA) are the precursors of potent lipid mediators and play an important role in regulation of inflammation. Generally, n-6 PUFA promote inflammation whereas n-3 PUFA have antiinflammatory properties, traditionally attributed to their ability to inhibit the formation of n-6 PUFA-derived proinflammatory eicosanoids. Newly discovered resolvins and protectins are potent antiinflammatory lipid mediators derived directly from n-3 PUFA with distinct pathways of action. However, the role of the n-3 PUFA tissue status in the formation of these antiinflammatory mediators has not been addressed. Here we show that an increased n-3 PUFA tissue status in transgenic mice that endogenously biosynthesize n-3 PUFA from n-6 PUFA leads to significant formation of antiinflammatory resolvins and effective reduction in inflammation and tissue injury in colitis. The endogenous increase in n-3 PUFA and related products did not decrease n-6 PUFA-derived lipid mediators such as leukotriene B4 and prostaglandin E2. The observed inflammation protection might result from decreased NF-kappaB activity and expression of TNFalpha, inducible NO synthase, and IL-1beta, with enhanced mucoprotection probably because of the higher expression of trefoil factor 3, Toll-interacting protein, and zonula occludens-1. These results thus establish the fat-1 transgenic mouse as a new experimental model for the study of n-3 PUFA-derived lipid mediators. They add insight into the molecular mechanisms of inflammation protection afforded by n-3 PUFA through formation of resolvins and protectins other than inhibition of n-6 PUFA-derived eicosanoid formation.

Increased cytokine transcripts in pouchitis reflect the degree of inflammation but not the underlying entity

BACKGROUND AND AIMS

After ileopouch anal anastomosis (IPAA), 10-40% of patients with ulcerative colitis (UC) but only 5% of patients with familial adenomatous polyposis (FAP) develop pouchitis. Immunoregulatory abnormalities might be of importance in the pathogenesis of the disease. Therefore, we characterized cytokine and chemokine transcripts in inflamed and non-inflamed pouches in patients with UC compared to those with FAP and Crohn's disease (CD).

PATIENTS AND METHODS

Mucosal biopsies were taken from 87 patients with IPAA [UC (n=70), CD (n=8) or FAP (n=9)]. Patients with active ileal CD (n=14), active UC (n=17) and non-inflammatory conditions (n=12) served as controls. The expression of 20 gene transcripts was quantified using real-time polymerase chain reaction.

RESULTS AND FINDINGS

Pro-inflammatory cytokines and chemokines are significantly increased in IPAA patients with acute pouchitis. This increase is independent of the underlying disease (UC or CD) and reflects the degree of inflammation. A good correlation between pouchitis activity (using the Pouchitis Disease Activity Index) and the MRP-14, interleukin-8, macrophage inflammatory protein-2alpha and matrix metalloproteinase-1 transcripts was observed.

INTERPRETATIONS AND CONCLUSIONS

Our data support the view that pouchitis reflects an inflammatory process that is different from that of underlying inflammatory bowel diseases, as the cytokine and chemokine patterns in pouchitis are neither typical of CD nor of UC, but maybe due to bacterial intestinal microflora overgrowth in the pouch lumen. Quantification of transcript levels allows an estimation of the extent of mucosal inflammation and may become helpful in the evaluation of the disease, especially in clinical trials.

Preliminary data on the use of apheresis in inflammatory bowel disease

In patients with inflammatory bowel disease (IBD), centrifugation has been attempted to remove leukocyte components from whole blood; however, the use of selective filters has proved to result in more active modification of cellular immunity in that 4 times as many white blood cells are removed, which may result in a greater therapeutic effect. Selective apheresis for treatment of IBD, in particular ulcerative colitis (UC), has been used in Japan and some European countries for several years; pilot studies with Adacolumn, a selective therapeutic granulocyte/monocyte apheresis device, in patients with IBD have recently been completed in the United States with favorable results. Unlike conventional pharmacological treatments, selective apheresis may be associated with a relatively low rate of adverse events. Multiple studies have suggested that selective apheresis may be of benefit as a steroid-sparing treatment. In an unblinded randomized trial in 69 steroid-dependent patients with active UC randomized to selective apheresis with Adacolumn or an increased dose of prednisolone, 83% of patients receiving Adacolumn achieved remission compared with 65% of those receiving an increased dose of prednisolone. In another uncontrolled study of 60 patients with active UC, treatment with Adacolumn selective apheresis enabled nearly 70% of steroid-dependent patients to discontinue prednisolone. An unblinded randomized controlled trial of a different selective apheresis device (Cellsorba) versus high-dose prednisolone in patients with active UC showed a greater therapeutic effect (74%) than high-dose prednisolone (38%) and lower frequency of adverse effects (24% versus 68%).

Immunomodulatory benefits of cyclosporine A in inflammatory bowel disease

Etiopathogenesis of mucosal inflammation in inflammatory bowel disease remains a complex and enigmatic field; various factors (genetic, environmental and microbial) trigger an event that activates intestinal immune and nonimmune systems culminating in inflammation and tissue injury. Specifically, both innate and adaptive immune systems seem to play important roles in the pathophysiology of this disease. Cyclosporine A represents a macrolide immune modulator with primary inhibitory effects on T helper lymphocyte production of interleukin-2, and other cytokines leading to altered T-lymphocyte and B-lymphocyte function. The diversity of its therapeutic outcome reported in inflammatory bowel disease may be due to the intricate immuno-pathogenic profile of the disease and the variety of the applied dose-dependent courses of therapy. Cyclosporine A exerts additional actions on other components of the inflammatory infiltrate, including neutrophils and mast cells, thereby appearing to be a multi-dynamic therapeutic approach, although with potential drawbacks, that may be applied alone or combined with other immunomodulatory agents in inflammatory bowel disease patients. Because cyclosporine A induces apoptosis of T-lymphocytes responsible for perpetuation of the chronic inflammatory process in the disease with potential tumorigenic effect, it may exert a further inhibitory effect on cancer development in inflammatory bowel disease patients, and can be combined with other relative agents, such as rapamycin, which also promotes T-lymphocyte apoptosis. Therefore, recently established multifactorial action of cyclosporine A in relation to the pathogenesis of the disease can open new horizons for prospective, controlled trials in large cohorts, aiming to emphasize cyclosporine A's potential.

Intraperitoneal cytokine productions and their relationship to peritoneal sepsis and systemic inflammatory markers in patients with inflammatory bowel disease

PURPOSE

This prospective, blinded study was designed to assess intraperitoneal cytokine productions and their relationship to clinical presentations and systemic inflammatory markers in patients with inflammatory bowel disease.

METHODS

Fifty patients who required abdominal surgery for active inflammatory bowel disease (ulcerative colitis, 27; and Crohn's disease, 23) were investigated. Interleukin-1beta, interleukin-6, and tumor necrosis factor-alpha levels in intraperitoneal fluid (obtained by intraoperative lavage) and plasma were measured by enzyme-linked immunosorbent assay. To compare intraperitoneal cytokine productions between diseases with a different degree of inflammation, intraperitoneal cytokine measurement also was performed for patients who required surgery for colorectal cancer (n = 25) and acute appendicitis (n = 25).

RESULTS

The median intraperitoneal cytokine (interleukin-1beta, interleukin-6, and tumor necrosis factor-alpha) levels were significantly higher in patients with inflammatory bowel disease than in patients with colorectal cancer and acute appendicitis. In patients with inflammatory bowel disease, intraperitoneal cytokine levels were significantly higher in patients with intraperitoneal sepsis (abscess/fistula) than in patients without intraperitoneal sepsis at laparotomy. Intraperitoneal cytokine levels did not correlate with type of disease (ulcerative colitis/Crohn's disease), age, gender, duration of disease before surgery, preoperative medical treatment, and the extent or site of disease. There were no significant correlations between intraperitoneal cytokine levels and the following systemic inflammatory markers: plasma cytokine levels, white blood cell count, platelet count, erythrocyte sedimentation rate, and C-reactive protein levels. Postoperative intraperitoneal septic complications (anastomotic leak/abscess/enterocutaneous fistula) more frequently occurred in patients with higher intraperitoneal cytokine levels.

CONCLUSIONS

Intraperitoneal cytokine productions were greatly elevated in patients with inflammatory bowel disease, and their levels correlated with the presence of intraperitoneal sepsis at laparotomy and development of postoperative intraperitoneal septic complications. Intraperitoneal cytokine levels showed no correlations with systemic inflammatory markers.

Postoperative change of mucosal inflammation at strictureplasty segment in Crohn's disease: cytokine production and endoscopic and histologic findings

PURPOSE

This study was designed to examine postoperative change of mucosal inflammation at strictureplasty segment in Crohn's disease mainly by cytokine measurements.

METHODS

Patients who underwent strictureplasty for Crohn's disease in the terminal ileum were investigated. Mucosal samples at the strictureplasty site were obtained during operation. At 3, 6, and 12 months after operation, biopsy specimens were taken from the strictureplasty site and macroscopically normal ileum at endoscopy. Mucosal cytokine concentrations were measured by enzyme-linked immunosorbent assay.

RESULTS

The mucosal concentrations of proinflammatory cytokines (interleukin-1beta, interleukin-6, interleukin-8, and tumor necrosis factor-alpha) and anti-inflammatory mediator (interleukin-1 receptor antagonist) at the strictureplasty segment greatly increased at the time of operation. Interleukin-1beta, interleukin-1 receptor antagonist, interleukin-6, interleukin-8, and tumor necrosis factor-alpha concentrations at the strictureplasty segment decreased during a 12-month period after operation. Twelve months after operation there was no significant difference in each cytokine concentration between the strictureplasty and macroscopically normal segments. The mucosal interleukin-1 receptor antagonist/interleukin-1beta ratio at the strictureplasty segment increased during a 12-month period after operation. Twelve months after operation there was no significant difference in the ratio between the strictureplasty and macroscopically normal segments. The endoscopic and histologic severities of mucosal inflammation at the strictureplasty site also decreased; however, their findings were not normalized during the study.

CONCLUSIONS

During one year after strictureplasty for Crohn's disease, cytokine production at the strictureplasty segment was decreased to the level of the macroscopically normal ileum and an imbalance between proinflammatory and antiinflammatory cytokines was corrected.

Mucosal cytokine production during remission after resection for Crohn's disease and its relationship to future relapse

AIM

To examine whether mucosal cytokine production during remission after resection for Crohn's disease is a predictor of future relapse.

METHODS

Thirty-six patients who remained in remission after resection for terminal ileal or ileo-caecal Crohn's disease were included. At enrollment, blood and mucosal (ileal and rectal biopsies) samples were collected. All patients were followed up regularly for 1 year after enrollment and the disease activity was assessed according to the Crohn's disease activity index.

RESULTS

Twenty patients remained in remission and 16 patients relapsed during the 1-year follow-up. Interleukin-1 beta, interleukin-6 and tumour necrosis factor-alpha levels in the ileal mucosa were significantly higher in relapsed patients than in patients in remission. These cytokine levels in the rectal mucosa were not associated with relapse. Conventional blood markers and plasma cytokine levels did not correlate with relapse. Amongst the clinical parameters, a younger age, short disease duration before operation and fistulating disease were risk factors for relapse. In multivariate analysis, only the ileal interleukin-6 level was an independent significant predictor for relapse.

CONCLUSIONS

The interleukin-6 level in the ileal mucosa during remission after resection for ileal or ileo-caecal Crohn's disease is an independent significant predictor for future relapse.

The effect of etanercept and infliximab on the production of tumour necrosis factor alpha, interferon-gamma and GM-CSF in in vivo activated intestinal T lymphocyte cultures

BACKGROUND/AIMS

Infliximab (Ifx) is effective in the treatment of Crohn's disease (CD) and rheumatoid arthritis (RA), etanercept (Eta) in RA but not in CD. The mechanisms underlying these clinical differences are not fully understood, but this knowledge could be valuable to identify responders and develop new treatments. This study compares Eta and Ifx in vitro regarding transmembrane tumour necrosis factor alpha (tmb-TNF-alpha) expression and interferon-gamma (IFN-gamma), TNF-alpha and granulocyte macrophage colony stimulating factor (GM-CSF) production in intestinal T lymphocytes.

METHODS

T lymphocyte cultures were established from biopsies from 10 CD patients and three healthy controls. The cytokine production and the expression of tmb-TNF-alpha were measured in the presence of Ifx/Eta.

RESULTS

Eta and Ifx downregulated the production of IFN-gamma and GM-CSF in colonic T lymphocytes from CD patients and healthy controls. Both drugs bound tmb-TNF-alpha on activated T lymphocytes besides neutralising TNF-alpha, Eta less efficiently than Ifx (406 pg/ml (337-475); 133 pg/ml (119-147); p=0.004). TNF-alpha was detectable with the present assay in cell lines cultured in the presence of excess Eta.

CONCLUSIONS

We have established that Eta is just as efficient as Ifx in downregulating IFN-gamma and GM-CSF production in vitro and Eta bound to tmb-TNF-alpha. However, Eta bound the TNF-alpha molecule, important in CD, less efficiently than Ifx.

Perspectives on osteoporosis in pediatric inflammatory bowel disease

Osteoporosis is now recognized as a problem in children with chronic illness. Decreased bone mineral density and increased risk of fracture have been reported in children with inflammatory bowel disease (IBD). Recent studies have led to a better understanding of the pathogenesis of bone loss. There are many risk factors for osteopenia and osteoporosis in children with IBD. Dual-energy x-ray absorptiometry remains the diagnostic procedure of choice for assessment of bone mineral density, but other modalities are being explored. Guidelines for diagnosis and treatment of osteoporosis in children have not been established. This article reviews the current understanding of osteopenia and osteoporosis in children with IBD.

Connections between psoriasis and Crohn's disease

The prevalence of psoriasis in patients with Crohn's disease (CD) is higher than chance would allow if they were mutually exclusive diseases. A close examination reveals genetic and pathologic connections between these diseases. An appreciation for the role of tumor necrosis factor-alpha in both diseases has proven very important. Increased levels of this inflammatory cytokine have been measured in CD lesions, and in 1997 a clinical trial demonstrated the response of this disease to infliximab, a monoclonal antibody specific for tumor necrosis factor-alpha. A subsequent clinical trial evaluated infliximab in a patient with CD and psoriasis, another disease in which increased levels of tumor necrosis factor-alpha are seen in lesions. Scientists noticed the marked skin improvement of this patient and later demonstrated the efficacy of infliximab for psoriasis in a randomized, double-blind, placebo-controlled trial. Thus, an appreciation for connections between psoriasis and CD can suggest novel therapeutic strategies with ensuing benefits to patients. This article reviews epidemiologic, genetic, and pathologic connections between psoriasis and CD and discusses pharmaceuticals targeting inflammatory mediators common to each disease. (J Am Acad Dermatol 2003;48:805-21.)

LEARNING OBJECTIVE

At the completion of this learning activity, participants should understand how psoriasis and Crohn's disease are related at epidemiologic, genetic, and pathological levels and should appreciate how to use this knowledge to treat these diseases.

Subclinical intestinal inflammation: an inherited abnormality in Crohn's disease relatives?

BACKGROUND & AIMS

One approach to unraveling the genetics of complex inherited disease, such as Crohn's disease, is to search for subclinical disease markers among unaffected family members. We assessed the possible presence, prevalence, and inheritance pattern of subclinical intestinal inflammation in apparently healthy relatives of patients with Crohn's disease.

METHODS

A total of 49 patients with Crohn's disease, 16 spouses, and 151 (58%) of 260 available first-degree relatives underwent a test for intestinal inflammation (fecal calprotectin concentration). The mode of inheritance was assessed from 36 index patients (by variance component analysis) when more than 50% of relatives were studied.

RESULTS

Fecal calprotectin concentrations in patients with Crohn's disease (47 mg/L; confidence interval [CI], 27-95 mg/L) and relatives (11 mg/L; CI, 9-14 mg/L) differed significantly (P < 0.0001) from controls (4 mg/L; CI, 3-5 mg/L), whereas that of the spouses did not (4 mg/L; CI, 3-6 mg/L; P > 0.5). Fecal calprotectin concentration was increased in 49% of all relatives studied. The increased fecal calprotectin concentration among the relatives of the 36 index patients had an inheritance pattern that was most consistent with an additive inheritance pattern.

CONCLUSIONS

There is a high prevalence of subclinical intestinal inflammation in first-degree relatives of patients with Crohn's disease that conforms best to an additive inheritance pattern. The genetic basis for this abnormality may represent a risk factor for Crohn's disease.

Enteral administration of hematopoietic growth factors in the neonatal intensive care unit

By 20 wk of gestation, the human fetal gastrointestinal (GI) tract morphologically resembles that of the term infant, but functional development is limited before 26 wk. By 30 wk of gestation, the fetus has the capacity for limited digestion and enteral absorption. GI growth and development continue postnatally. Trophic factors, including nutrients, peptides, hormones and growth factors, are recognized as having important influences on the morphology and histology of the developing GI tract. Other trophic factors are important in adaptation and repair following injury. Many such factors are provided in utero via amniotic fluid swallowing and later by human colostrum and milk.

CONCLUSION

This review discusses cytokines with known GI trophic effects, either in vitro or in vivo, and focuses on those cytokines that have been used in the neonatal intensive care unit.

IL-10 producing CD14low monocytes inhibit lymphocyte-dependent activation of intestinal epithelial cells by commensal bacteria

Intestinal epithelial cell (IEC) activation by non-pathogenic, commensal bacteria was demonstrated to require the presence of immunocompetent cells. In this study, HT-29 and CaCO-2 transwell cultures, reconstituted with CD4+ and CD8+ T cells, CD19+ B cells and CD14high monocytes, were challenged with non-pathogenic Gram negative Escherichia coli and Gram positive lactobacilli. Cytokine expression was analysed by reverse transcription-polymerase chain reaction (RT-PCR) and enzyme linked immunosorbent assays (ELISA). Expression of tumour necrosis factor alpha (TNF-alpha) and interleukin (IL)-8 mRNA in E. coli or L. sakei challenged IEC was promoted by lymphocyte populations predominantly CD4+ T cells, while monocytes failed to mediate an inflammatory cytokine response. The monocyte phenotype and function were further characterised by flow cytometry and mixed lymphocyte reaction (MLR). During the co-culture with IEC and bacterial stimulated IEC, CD14high peripheral blood monocytes acquired a CD14low CD16low phenotype with reduced expression co-stimulatory (CD80, CD86, CD58) cell surface molecules. Immunosuppressive functions of IEC conditioned CD14low monocytes were demonstrated by the predominant secretion of IL-10 and IL-IRa and their reduced potential to trigger an allogeneic lymphocyte response. In conclusion, IEC contribute to the development of CD14low CD16low monocytes with immunosuppressive function and antagonised a lymphocyte-mediated activation of the intestinal epithelium in response to intestinal and food derived bacteria. These results strengthen the hypothesis that the gut epithelium constitutes an important functional element in the regulation of mucosal immune homeostasis towards commensal bacteria.

Frequency of continuing mucosal inflammation in clinically inactive Crohn's disease

The treatment goal in Crohn's disease is clinical remission, not complete mucosal healing. The incidence of mucosal inflammation in Crohn's disease patients in clinical remission is not known. Whole gut lavage is an objective method of assessing mucosal inflammation. We aimed to assess levels of mucosal inflammatory activity in a group of patients with clinically inactive Crohn's disease. We prospectively assessed 30 patients with inactive Crohn's disease and 28 controls. Inactive disease was defined as Crohn's disease activity index of less than 150. All underwent whole put lavage, with analysis of whole gut lavage fluid IgG, haemoglobin, interleukin-1 beta, interleukin-8 and granulocyte elastase. Serum inflammatory parameters were collected for comparison. Of the 30 patients with Crohn's disease, 10 (33%) had an abnormal immunoglobulin G, 21 (70%) had an elevated interleukin-1 beta 20 (66%) interleukin-8 and 10 (33%) granulocyte elastase in the whole gut lavage fluid. 58% of patients had either 1 or 2 abnormal results. In contrast only 10% had 1 or 2 abnormal serum results. Few abnormalities were present in lavage fluid or serum of the control population. We concluded that ongoing mucosal inflammation is detectable in whole gut lavage fluid of up to 2/3 of Crohn's disease patients in clinical remission.

Peptide growth factors in the intestine

A continuously increasing number of regulatory peptides has been demonstrated to be expressed in the intestine and to modulate several functional properties of various intestinal cell populations, including the intestinal epithelium and lamina propria cell populations. These regulatory peptides include members of the epidermal growth factor (EGF) family, the transforming growth factor beta (TGF-beta) family, the insulin-like growth factor (IGF) family, the fibroblast growth factor (FGF) family, the trefoil factor (TFF) family, the colony-stimulating factor (CSF) family, and a few other seemingly unrelated regulatory peptides, such as hepatocyte growth factor (HGF), platelet-derived growth factor (PDGF), and various interleukins, interferons and tumour necrosis factor-related proteins. In addition to the well-known effects on cell proliferation, these regulatory peptide factors regulate several other functional properties of epithelial and other cell populations, such as differentiation, migration, and extracellular matrix deposition and degradation. This review is designed not to discuss all the identified factors in detail but to highlight some of the basic principles of growth factor action in the intestine. It focuses mainly on classical growth factors rather than interleukins and interferons.

[Importance of serum albumin values in nutritional assessment and inflammatory activity in patients with Crohn's disease]

BACKGROUND

The serum albumin concentration has frequently been regarded as an indicator of nutritional status, although the hypoalbuminemia may reflect an acute phase protein response during inflammation mediated by cytokines. Both hypoalbuminemia and malnutrition are observed in Crohn's disease.

OBJECTIVES

To correlate the serum albumin values to disease activity and also to nutritional status in patients with Crohn's disease.

PATIENTS/METHODS

Thirty six patients were studied. Nutritional status was assessed by anthropometry measures and inflammatory activity determined by Harvey's simple clinical index and erythrocyte sedimentation rate.

RESULTS

No correlation was found between malnutrition and hypoalbuminemia. The serum albumin levels correlated inversely with the disease activity. Hypoalbuminemia was 100% sensitive for detection of disease activity.

CONCLUSION

This study suggests that serum albumin concentration is a very sensitive marker of inflammatory activity and not good indicator of the nutritional status in Crohn's disease. It is necessary a suitable laboratorial parameter for routine nutrition assessment in patients with this inflammatory bowel disease.

Gut luminal neutrophil migration is influenced by the anatomical site of Crohn's disease

BACKGROUND

Clinical differences between small- and large-bowel Crohn's disease have been demonstrated. Neutrophil migration and degranulation are important effector mechanisms in gut damage. Granulocyte elastase, a neutrophil-bound enzyme, interleukin 8 and 1beta can be detected in whole-gut lavage fluid. We aimed to assess differences between large- and small-bowel Crohn's disease.

METHODS

A total of 167 patients with active inflammatory bowel disease (118 Crohn's disease, 49 ulcerative colitis) underwent whole-gut lavage with a polyethylene glycol electrolyte solution. Granulocyte elastase was assayed using an enzyme substrate reaction, IL-8 and IL-1beta by ELISA.

RESULTS

Twenty-seven of 36 patients with isolated colonic Crohn's disease had detectable granulocyte elastase (median 0.259 pKat/l, range < 0.039-2.742 microKat/l), whereas 3 of 15 with small-bowel involvement alone had detectable granulocyte elastase (median < 0.039 microKat/l, range < 0.039-0.266 microKat/l; P < 0.0001). Granulocyte elastase levels were significantly higher in patients with ileocolonic disease and post-ileocaecal resection compared with small-bowel disease alone. IL-8 (P< 0.0001) and IL-1beta (P < 0.04) levels differed between colonic and ileal distributions. No variations were seen in ulcerative colitis.

CONCLUSIONS

Neutrophil migration to the gut lumen in Crohn's disease is a feature of colonic disease irrespective of associated ileal lesions. This suggests that bacterial-derived chemo-attractants may play a role. High levels of IL-8 in colonic disease are consistent with this hypothesis.

Patients with inflammatory bowel disease (IBD) reveal increased induction capacity of intracellular interferon-gamma (IFN-gamma) in peripheral CD8+ lymphocytes co-cultured with intestinal epithelial cells

Intestinal epithelial cells seem to play a key role during IBD. The network of cellular interactions between epithelial cells and lamina propria mononuclear cells is still incompletely understood. In the following co-culture model we investigated the influence of intestinal epithelial cells on cytokine expression of T cytotoxic and T helper cells from patients with IBD and healthy controls. Peripheral blood mononuclear cells (PBMC) were purified by a Ficoll-Hypaque gradient followed by co-incubation with epithelial cells in multiwell cell culture insert plates in direct contact as well as separated by transwell filters. We used Caco-2 cells as well as freshly isolated colonic epithelia obtained from surgical specimens. Three-colour immunofluorescence flow cytometry was performed after collection, stimulation and staining of PBMC with anti-CD4, anti-CD8, anti-IFN-gamma and anti-IL-4. Patients with IBD (Crohn's disease (CD), n = 12; ulcerative colitis (UC), n = 16) and healthy controls (n = 10) were included in the study. After 24 h of co-incubation with Caco-2 cells we found a significant increase of IFN-gamma-producing CD8+ lymphocytes in patients with IBD. In contrast, healthy controls did not respond to the epithelial stimulus. No significant differences could be found between CD and UC or active and inactive disease. A significant increase of IFN-gamma+/CD8+ lymphocytes in patients with UC was also seen after direct co-incubation with primary cultures of colonic crypt cells. The observed epithelial-lymphocyte interaction seems to be MHC I-restricted. No significant epithelial cell-mediated effects on cytokine expression were detected in the PBMC CD4+ subsets. Patients with IBD-even in an inactive state of disease-exert an increased capacity for IFN-gamma induction in CD8+ lymphocytes mediated by intestinal epithelial cells. This mechanism may be important during chronic intestinal inflammation, as in the case of altered mucosal barrier function epithelial cells may become targets for IFN-gamma-producing CD8+ lymphocytes.

Mesalazine inhibits activation of transcription factor NF-kappaB in inflamed mucosa of patients with ulcerative colitis

OBJECTIVES

The salicylate mesalazine is commonly used for the treatment of inflammatory bowel diseases, yet its precise mechanism of action is unknown. Because transcription factor NF-kappaB plays an important role in inflammatory bowel diseases, we investigated the effects of mesalazine therapy on NF-kappaB activation in patients with ulcerative colitis.

METHODS

A total of 20 patients with moderately active ulcerative colitis received mesalazine for 8 wk. Biopsies were taken before and after drug administration and analyzed for NF-kappaB activation using an antibody specific for active NF-kappaB.

RESULTS

In biopsies of active ulcerative colitis but not in noninflamed mucosa, activation of NF-kappaB was detected predominantly in macrophages. Mesalazine therapy resulted, in a strong abrogation of NF-kappaB activation in situ.

CONCLUSIONS

Our results suggest that the therapeutic properties of mesalazine rely at least in part on the inhibition of NF-kappaB activation, resulting in the suppression of proinflammatory gene expression in the inflamed mucosa.

Recombinant human interleukin 10 in the treatment of patients with mild to moderately active Crohn's disease. The Interleukin 10 Inflammatory Bowel Disease Cooperative Study Group

BACKGROUND & AIMS

Interleukin 10 (IL-10) is an anti-inflammatory, immunomodulatory cytokine that regulates mucosal inflammation. This study evaluated the safety, tolerance, and efficacy of recombinant human IL-10 (rhuIL-10) for mild to moderately active Crohn's disease.

METHODS

We conducted a 24-week multicenter, prospective, randomized, double-blind, placebo-controlled, and sequential-escalating-dose study. Ninety-five patients with Crohn's Disease Activity Index of 200-350, not presently undergoing corticosteroid, mesalamine, or immunosuppressive therapy, were treated with subcutaneous rhuIL-10 (1, 5, 10, or 20 microg/kg) or placebo once daily for 28 consecutive days. Patients were followed up for 20 weeks after treatment. Evaluation of safety and tolerance was the first objective, and efficacy was the second objective.

RESULTS

Adverse effects were dose-related, mild-to-moderate in severity, and reversible. Asymptomatic and reversible anemia and thrombocytopenia were observed at higher doses. No withdrawal or delayed adverse effects were evident during 20 weeks of follow-up. At the end of treatment (day 29), intent-to-treat analysis showed that 23.5% (confidence interval [CI], 6.8%-49.9%) of patients receiving 5 micro/kg rhuIL-10 experienced clinical remission and endoscopic improvement; 0% (CI, 0%-14.8%) of patients in the placebo group did. Higher doses of recombinant human IL-10 were less effective than 5 microg/kg. No rhuIL-10 serum accumulation and no antibody against IL-10 were detected after 4 weeks.

CONCLUSIONS

Subcutaneous rhuIL-10 administered daily for 28 days to patients with mild to moderately active Crohn's disease is safe, well-tolerated, and shows clinical and endoscopic improvement.

Necrotizing enterocolitis and hematopoietic cytokines

The names of the hematopoietic cytokines are misleading because in addition to their effects on bone marrow and bone marrow-derived cells, they have many diverse effects, including effects on the gastrointestinal tract. These effects may be directly mediated by interaction with specific receptors on gastrointestinal epithelial cells, or they may result from their effects on circulating or bowel wall leukocytes and the cytokines these cells produce. As might be expected of factors largely defined by their effects on inflammatory cells, the hematopoietic cytokines are intimately involved in the processes of bowel injury. Further investigations are needed to define the role of hematopoietic cytokines in the human neonate's balance between local gastrointestinal host defense and bowel wall injury. This could lead to effective strategies for the treatment and prevention of NEC.