Cytokines, chemokine receptors, and homing molecule distribution in the rectum and stomach of pediatric patients with ulcerative colitis

Importance of eosinophilic infiltration of the colonic mucosa in ulcerative colitis patients who are refractory to maintenance therapy: A prospective, single-center study

Eosinophilic infiltration is sometimes observed histologically in ulcerative colitis (UC), but the effect of the degree of infiltration on the treatment course for UC is not completely understood. We investigated whether short-term steroid administration in UC patients refractory to maintenance therapy, with high eosinophilic infiltration in the colonic mucosa, contributed to the clinical and endoscopic improvement. Ten patients with endoscopically active and pathologically high eosinophilic infiltration, based on pathological examination using endoscopic biopsy, were examined for the clinical background when starting steroid treatment. The clinical and endoscopic improvement before and after steroid use were assessed prospectively. The average initial steroid dosage and duration of use were 21.0 mg and 102.7 days, respectively. The mean values before and after steroid use of the clinical activity index, the Mayo endoscopic subscore, and the UC endoscopic index of severity were 2.4 and 1.0, 1.8 and 0.7, and 3.9 and 1.1, respectively. All scores improved significantly after steroid use (P = .042, P = .002, P = .002, respectively). Steroids were discontinued in all patients; no patients required steroid re-administration. There may be cases of UC with eosinophilic infiltration into the colonic mucosa and resistance to maintenance treatment, suggesting that short-term steroid administration may contribute to clinical and endoscopic improvements.

Mucosal lesions of the upper gastrointestinal tract in patients with ulcerative colitis: A review

Ulcerative colitis (UC) is a chronic, nonspecific, relapsing inflammatory bowel disease. The colorectum is considered the chief target organ of UC, whereas upper gastrointestinal (UGI) tract manifestations are infrequent. Recently, emerging evidence has suggested that UC presents complications in esophageal, stomachic, and duodenal mucosal injuries. However, UC-related UGI tract manifestations are varied and frequently silenced or concealed. Moreover, the endoscopic and microscopic characteristics of UGI tract complicated with UC are nonspecific. Therefore, UGI involvement may be ignored by many clinicians. In addition, no standard criteria have been established for patients with UC who should undergo fibrogastroduodenoscopy. Furthermore, specific treatment recommendations may be needed for patients with UC-associated UGI lesions. Herein, we review the esophageal, gastric, and duodenal mucosal lesions of the UC-associated UGI tract, as well as the potential pathogenesis and therapy.

Intestinal Mucosal Wound Healing and Barrier Integrity in IBD-Crosstalk and Trafficking of Cellular Players

The intestinal epithelial barrier is carrying out two major functions: restricting the entry of potentially harmful substances while on the other hand allowing the selective passage of nutrients. Thus, an intact epithelial barrier is vital to preserve the integrity of the host and to prevent development of disease. Vice versa, an impaired intestinal epithelial barrier function is a hallmark in the development and perpetuation of inflammatory bowel disease (IBD). Besides a multitude of genetic, molecular and cellular alterations predisposing for or driving barrier dysintegrity in IBD, the appearance of intestinal mucosal wounds is a characteristic event of intestinal inflammation apparently inducing breakdown of the intestinal epithelial barrier. Upon injury, the intestinal mucosa undergoes a wound healing process counteracting this breakdown, which is controlled by complex mechanisms such as epithelial restitution, proliferation and differentiation, but also immune cells like macrophages, granulocytes and lymphocytes. Consequently, the repair of mucosal wounds is dependent on a series of events including coordinated trafficking of immune cells to dedicated sites and complex interactions among the cellular players and other mediators involved. Therefore, a better understanding of the crosstalk between epithelial and immune cells as well as cell trafficking during intestinal wound repair is necessary for the development of improved future therapies. In this review, we summarize current concepts on intestinal mucosal wound healing introducing the main cellular mediators and their interplay as well as their trafficking characteristics, before finally discussing the clinical relevance and translational approaches to therapeutically target this process in a clinical setting.

Ulcerative colitis with mucosal lesions in duodenum: Two case reports

RATIONALE

Ulcerative colitis (UC) is a chronic, nonspecific, inflammatory disease of the colon. Colorectal is the main target organ of UC, while other digestive tract involvement is rare. This report describes 2 rare cases of duodenal mucosa lesions in patients with UC after total colectomy.

PATIENT CONCERNS

In case 1, a patient of 45-year-old with intermittent diarrhea and bloody mucosanguineous feces who was diagnosed as UC, revealed diffuse erosive ulcers in the descending duodenum through gastroscopy after total colectomy. In case 2, a 55-year-old Chinese female with UC, aggravated to colon cancer and received total colectomy. Eighteen months after surgery, the patient was admitted to hospital following upper abdominal pain and acid regurgitation. A gastroscopy found inflammation in the descending part of the duodenum.

DIAGNOSIS

UC, duodenal mucosa lesions INTERVENTIONS:: In case 1, the patient was treated with oral mesalazine (1 g/tid) and hydrocortisone (0.3 g/d) but symptoms did not improve, and the treatment was changed to oral methylprednisolone (0.6 g/d) and a hydrocortisone enema (0.1 g/late). Finally, the patient underwent a total colectomy and ileostomy. In case 2, the patient was treated with sulfasalazine, mesalazine, and intermittent hormone enemas. A total colectomy and ileostomy were performed with the patient after diagnosed as colon cancer. After surgery, the patient received N1-(2 tetrahydrofuryl)-5-fluorouracil (FT-207), 8 g, 300 mg, and 100 mg oxaliplatin chemotherapy, and biologic therapy.

OUTCOMES

In case 1, the patient presented with duodenal necrosis and died of septic shock. In case 2, the patient recovered well without recurrence by taking proton pump inhibitor.

LESSONS

The occurrence of UC related ulcerative gastroduodenal mucosal lesions may be associated with progressing UC or total colitis that does not respond to hormone therapy, leading to requirement of total colectomy.

Value of upper endoscopic biopsies in predicting medical refractoriness in pediatric patients with ulcerative colitis

Refractory ulcerative colitis (UC) occurs in patients who experience a severe disease manifestation that is unresponsive to medical therapy. The assessment of upper endoscopic microscopic findings and its correlation with refractory UC has not been fully studied in pediatric patients and is the focus of this study. Medical records of UC patients treated at a tertiary pediatric center between 2000 and 2014 were reviewed. Endoscopic biopsies of the upper gastrointestinal (GI) tract of patients meeting a priori inclusion criteria were compared between refractory UC patients and nonrefractory UC patients for active inflammation. Statistically significant differences were determined between groups, and tissues shown to have significant differences were further evaluated for their diagnostic performance. A total of 52 patients were included, 26 in each group. Significant differences were observed in intraepithelial neutrophil infiltration and percentage involvement of crypts/glands for the antrum, body, and duodenal bulb (P ≤ .001, .005, and .01 [intraepithelial neutrophil infiltration] and P = .001, .009, and .015 [% involvement], respectively). Microabscesses of mucosal glands/crypts were also experienced in a greater number of refractory UC patients in the stomach (ie, antrum and/or body of stomach; P = .005) and duodenum (ie, duodenum and/or duodenal bulb; P = .023). The sensitivity and specificity of upper GI tissues to predict refractory UC were moderate, with sensitivities ranging from 38% to 67% and specificities ranging from 81% to 100%. Our results suggest that children with refractory UC are more likely to have active inflammation in the upper GI tract, and thus, this may represent a predictor of responsiveness to current medical therapy.

The Role of T-Cell Subsets in Chronic Inflammation in Celiac Disease and Inflammatory Bowel Disease Patients: More Common Mechanisms or More Differences?

Background

Chronic intestinal inflammation due to noninfectious causes represents a growing health issue all over the world. Celiac disease as well as inflammatory bowel diseases (IBD) like Crohn's disease and ulcerative and microscopic colitis involve uncontrolled T-cell activation and T-cell-mediated damage as common denominators. Therefore, diagnosis and treatment decisions clearly benefit from the knowledge of the intricacies of the systemic and the local T-cell activity.

Summary

Depending on the cytokine milieu, CD4⁺ T cells can differentiate into proinflammatory T helper 1 (Th1), anti-inflammatory Th2, antimicrobial Th17, pleiotropic Th9, tissue-instructing Th22 cells, and in the regulatory compartment forkhead box protein 3⁺ Treg, suppressive Tr1 or Th3 cells. Additionally, follicular Th cells provide B-cell help in antibody class switching; cytotoxic CD8⁺ T cells target virus-infected or tumor cells. This review discusses our current knowledge on the contribution of defined T-cell subpopulations to establishing and maintaining chronic intestinal inflammation in either of the above entities. It also puts emphasis on the differences in the prevalence of these diseases between Eastern and Western countries.

Key Messages

In celiac disease, the driving role of T cells in the lamina propria and in the epithelium mainly specific for two defined antigens is well established. Differences in genetics and lifestyle between Western and Eastern countries were instrumental in understanding underlying mechanisms. In IBD, the vast amount of potential antigens and the corresponding antigen-specific T cells makes it unlikely to find universal triggers. Increased mucosal CD4⁺ regulatory T cells in all four entities fail to control or abrogate local inflammatory processes. Thus, prevailing differences in the functional T-cell subtypes driving chronic intestinal inflammation in celiac disease and IBD at best allow some overlap in the treatment options for either disease.

B cells secrete eotaxin-1 in human inflammatory bowel disease

BACKGROUND

Our previous studies have demonstrated that B cells in human inflammatory bowel disease (IBD) are highly activated and produce copious amounts of chemokines. Here, we showed that B cells produce eotaxin-1, a selective chemokine for acute eosinophilia. Increased levels of activated eosinophils have been found in the intestinal mucosa in patients with IBD, but their role(s) and the regulation of their migration patterns remain poorly defined.

METHODS

To determine how B-cell secretion of eotaxin-1 influences eosinophil activation and migration, we performed immunoepidemiological approaches coupled with in vitro studies. B cells and eosinophils from patients with Crohn's disease and ulcerative colitis were isolated, and responses to Toll-like receptor ligands (TLR) were measured and assessed for the relationship with clinical disease.

RESULTS

Eotaxin-1 from recirculating B cells, and TLR ligands, regulated eosinophil homing mechanisms in IBD. B cells stimulated with hypo-acylated lipopolysaccharide (LPS) produced copious amounts of eotaxin-1, which influenced eosinophil activation profiles in the bloodstream. We also found that hexa-acylated LPS, such Escherichia coli LPS, directly activated TLR2-expressing and TLR4-expressing eosinophils from patients with IBD to express a different repertoire of mucosal homing receptors, namely CCR9 and CCR10. Whereas B-cell production of eotaxin-1 was correlated with reduced disease activity, eosinophil activation by hexa-acylated LPS was associated with increased disease activity.

CONCLUSIONS

These results suggest that systemic TLR ligands influence eosinophil migration patterns, both directly and indirectly, through B cells. Our report uncovers unexpected mechanisms of cross talk between certain immune cells that shed new light on IBD immunology.

Diagnostic yield of upper endoscopy in paediatric patients with Crohn's disease and ulcerative colitis. Subanalysis of the HUPIR registry

BACKGROUND, AIMS

According to Porto Criteria upper gastrointestinal (UGI) endoscopy is recommended in patients with suspected inflammatory bowel disease (IBD). Nevertheless, previous studies revealed frequent involvement of UGI tract even in patients with ulcerative colitis (UC). The aim of the present study was to determine the diagnostic role of esophagogastroduodenoscopy (EGD) and assess the prevalence and different aspects of UGI involvement in children registered in the Hungarian Pediatric IBD Registry (HUPIR) from 1st of January 2007 to 31th of December 2009.

METHODS

Twenty seven institutes provided prospective follow-up data about newly diagnosed IBD patients to HUPIR. The registry was based on detailed questionnaire (76 parameters) involving anamnestic data, laboratory findings, activity indexes, diagnostic procedures, endoscopic examinations (EGD and ileocolonoscopy), and histological data. Localization and phenotype of disease were based on the Montreal classification criteria.

RESULTS

During the 3-year period 420 children were diagnosed with IBD, 265 (63%) of them had Crohn's disease (CD), 130 (31%) UC, and 25 (6%) IBD-unclassified (IBD-U). The mean age at diagnosis was 13.2 years (range: 1.2-18 years). EGD was performed in 237 patients (56%), in most cases in patients suffering from CD. Macroscopic lesions on EGD were noted in 64% of patients with CD and 40% of children with UC. Characteristic lesions for CD (ulcer, erosion, aphthous lesion, and granuloma) were noted in 31% of CD patients, however, EGD helped to establish the final diagnosis in 9% of CD patients (diagnostic yield, 9%).

CONCLUSIONS

There was a high frequency of UGI involvement in children with CD and UC. One third of CD patients showed significant lesions at upper endoscopy and one patient out of ten had real diagnostic help from EGD.

Kalopanaxsaponin A ameliorates experimental colitis in mice by inhibiting IRAK-1 activation in the NF-κB and MAPK pathways

BACKGROUND AND PURPOSE

Kalopanaxsaponin A, a triterpenoid saponin isolated from Kalopanax pictus (family Araliaceae), potently inhibited nuclear factor-kappa B (NF-κB) activation in lipopolysaccharide (LPS)-stimulated peritoneal macrophages during a screening programme for anti-colitis agents from natural products. Its anti-inflammatory mechanism remains unknown. Therefore, we investigated its anti-inflammatory effects in lipopolysaccharide (LPS)- or peptidoglycan-stimulated murine peritoneal macrophages and trinitrobenzene sulphonic acid (TNBS)-induced colitic mice.

EXPERIMENTAL APPROACH

Peritoneal macrophages from male ICR mice were stimulated with LPS or peptidoglycan in vitro and treated with kalopanaxsaponin A. Colitis was induced in vivo by intrarectal administration of TNBS in male ICR mice. Mice were treated daily with kalopanaxsaponin A, sulphasalazine or phosphate-buffered saline. Inflammatory markers, cytokines, enzymes and transcription factors were measured by ELISA, immunoblot, flow cytometry and immunofluorescent confocal microscopy.

KEY RESULTS

Kalopanaxsaponin A potently inhibited the expression of the pro-inflammatory cytokines, interleukin (IL)-1β, tumour necrosis factor (TNF)-α and IL-6, induced by LPS, but not that induced by TNF-α, in peritoneal macrophages. However, it potently increased the expression of the anti-inflammatory cytokine IL-10. Kalopanaxsaponin A inhibited activation of the IL-1 receptor-associated kinase (IRAK)-1, inhibitor of κB kinase-β, NF-κB and mitogen-activated protein kinases (extracellular signal-regulated kinase, c-Jun NH(2) -terminal kinase, p-38), but LPS/Toll-like receptor-4 interaction and IRAK-4 activation were not affected. Oral administration of kalopanaxsaponin A (10 and 20 mg·kg(-1) ) improved the clinical parameters and histology in vivo. Kalopanaxsaponin A inhibited NF-κB and mitogen-activated protein kinase activation induced by TNBS by suppressing IRAK-1 activation.

CONCLUSIONS AND IMPLICATIONS

Kalopanaxsaponin A may improve inflammatory diseases, such as colitis, by inhibiting IRAK-1 activation.

Increased expression of chemokine receptor CCR3 and its ligands in ulcerative colitis: the role of colonic epithelial cells in in vitro studies

Human colonic epithelial cells express T helper type 1 (Th1)-associated chemoattractants, yet little is known about the production of Th2-associated chemoattractants. CCL11/eotaxin-1, CCL24/eotaxin-2 and CCL26/eotaxin-3 are known to attract CCR3-expressing, Th2-polarized lymphocytes. We studied constitutive and inflammation-induced expression and production of CCR3 together with its ligands in the colon and peripheral blood of patients with inflammatory bowel disease (IBD) by flow cytometry, reverse transcription–polymerase chain reaction (RT–PCR) and enzyme-linked immunosorbent assay (ELISA). We further defined the regulated expression of these chemokines by RT–PCR and ELISA using cultured human epithelial cell lines. A higher fraction of peripheral T lymphocytes were found to be positive for CCR3 in patients with ulcerative colitis (UC) compared to Crohn’s disease (CD), while almost no CCR3(+) T cells were found in normal controls (NC). Similarly, higher and more frequent expression of CCR3 was observed in colonic biopsies from patients with UC, regardless of the disease activity, when compared to CD or NCs. Serum CCL11/eotaxin-1 was increased significantly in UC (306 ± 87 pg/ml) and less so in CD (257 ± 43 pg/ml), whereas CCL24/eotaxin-2, and CCL26/eotaxin-3 were increased only in UC. Colonic expression of the three chemokines was minimal in NCs but high in inflammatory bowel diseases (especially UC) and was independent of disease activity. Th2, and to a lesser extent Th1, cytokines were able to induce expression and production of all three eotaxins from colonic epithelial cells in culture. CCR3 and ligands over-expression would appear to be a characteristic of UC. The production of CCR3 ligands by human colonic epithelial cells suggests further that epithelium can play a role in modulating pathological T cell-mediated mucosal inflammation.

Effect of probiotics on pro-inflammatory cytokines and NF-kappaB activation in ulcerative colitis

AIM

To demonstrate the therapeutic effect of probiotics in patients with ulcerative colitis (UC), and their effect on inflammatory mediators and nuclear factor (NF)-kappaB activation in these patients.

METHODS

Thirty patients with mild to moderate UC were randomly classified into two groups: sulfasalazine group, who received sulfasalazine 2400 mg/d; and probiotic group, who received sulfasalazine 2400 mg/d with probiotic. The patients were investigated before and after 8 wk of treatment with probiotic (Lactobacillus delbruekii and Lactobacillus fermentum). Colonic activity of myeloperoxidase (MPO) was assayed with UV spectrophotometry, the colonic content of interleukin (IL)-6 was determined by enzyme-linked immunosorbent assay (ELISA), fecal calprotectin was determined by ELISA, and expression of NF-kappaB p65 and tumor necrosis factor (TNF)-alpha proteins in colonic tissue was identified by immunohistochemistry and reverse transcription polymerase chain reaction, respectively.

RESULTS

At the start of the study, colonic mucosal injury and inflammation were demonstrated in UC patients by hematoxylin and eosin staining, and an increase in colonic MPO activity, fecal calprotectin, and expression of colonic TNF-alpha and NF-kappaB p65 proteins. The use of probiotic for 8 wk significantly ameliorated the inflammation by decreasing the colonic concentration of IL-6, expression of TNF-alpha and NF-kappaB p65, leukocyte recruitment, as demonstrated by a decrease in colonic MPO activity, and the level of fecal calprotectin compared to sulfasalazine group and the control group (P < 0.05).

CONCLUSION

Oral supplementation with probiotics could be helpful in maintaining remission and preventing relapse of UC.

Diagnosis and clinical course of ulcerative gastroduodenal lesion associated with ulcerative colitis: possible relationship with pouchitis

BACKGROUND AND AIM

  Ulcerative colitis (UC) is not only characterized by pathological lesions localized to colonic mucosa, but also to various complications involving other organs, including postoperative pouchitis. Among these complications, diffuse gastroduodenitis with lesions resembling colonic lesions has been reported, albeit rarely.The aim of the present study was to attempt to characterize the lesions of the upper gastrointestinal tract occurring as a complication of UC, and to assess the frequency and clinical course of these lesions.

METHODS

  A total of 322 UC patients who had undergone upper gastrointestinal endoscopy were retrospectively analyzed. We assessed the frequency of endoscopic findings, including diffuse gastroduodenal lesions resembling colonic lesions. Ulcerative gastroduodenal lesion (UGDL) associated with UC was diagnosed if lesions satisfied the following criteria: (i) improvement of the lesions with treatment of UC; and/or (ii) resemblance to UC in pathological findings.

RESULTS

  UGDL satisfying the aforementioned criteria was found in 15 (4.7%) of 322 patients. All the 15 patients had UGDL accompanied by pancolitis or after proctocolectomy. Frequency in 146 patients with pancolitis was 6.2% (nine patients) and that in 81 patients who had undergone proctocolectomy was 7.4% (six patients). Four patients with diffuse ulcerative upper-gastrointestinal mucosal inflammation (DUMI) had pouchitis. In all patients except one, the lesions resolved easily with medical treatment.

CONCLUSIONS

  In more than half of the post-proctocolectomy patients, UGDL was related to the occurrence of pouchitis. The existence of characteristic UGDL must be taken into account in the diagnosis and treatment of UC, and UGDL is possibly related to the occurrence of pouchitis.

Effect of probiotics on pro-inflammatory cytokines and NF-κB activation in ulcerative colitis

AIM: To demonstrate the therapeutic effect of probiotics in patients with ulcerative colitis (UC), and their effect on inflammatory mediators and nuclear factor (NF)-κB activation in these patients.

METHODS: Thirty patients with mild to moderate UC were randomly classified into two groups: sulfasalazine group, who received sulfasalazine 2400 mg/d; and probiotic group, who received sulfasalazine 2400 mg/d with probiotic. The patients were investigated before and after 8 wk of treatment with probiotic (Lactobacillus delbruekii and Lactobacillus fermentum). Colonic activity of myeloperoxidase (MPO) was assayed with UV spectrophotometry, the colonic content of interleukin (IL)-6 was determined by enzyme-linked immunosorbent assay (ELISA), fecal calprotectin was determined by ELISA, and expression of NF-κB p65 and tumor necrosis factor (TNF)-α proteins in colonic tissue was identified by immunohistochemistry and reverse transcription polymerase chain reaction, respectively.

RESULTS: At the start of the study, colonic mucosal injury and inflammation were demonstrated in UC patients by hematoxylin and eosin staining, and an increase in colonic MPO activity, fecal calprotectin, and expression of colonic TNF-α and NF-κB p65 proteins. The use of probiotic for 8 wk significantly ameliorated the inflammation by decreasing the colonic concentration of IL-6, expression of TNF-α and NF-κB p65, leukocyte recruitment, as demonstrated by a decrease in colonic MPO activity, and the level of fecal calprotectin compared to sulfasalazine group and the control group (P < 0.05).

CONCLUSION: Oral supplementation with probiotics could be helpful in maintaining remission and preventing relapse of UC.

Multistep mechanism of probiotic bacterium, the effect on innate immune system

The etiology and pathogenesis of inflammatory bowel disease are still not fully understood. However, evidence from both animal models and clinical observations suggests luminal bacteria as the most probable inducer of this disease. The intestinal bacterial microbiota may be modified by dietary addition of viable probiotic bacteria, thereby constituting an alternative approach to disease prevention and treatment. The aim of this study was to evaluate and compare the effects of two probiotic regiments; Lactobacillus GG and a mixture of Streptococcus thermophilus, Lactobacillus acidophilus, and Bifidobacterium lactis (YO-MIX Y 109 FRO 1000) in both normal and trinitrobenzenesulfonic acid colitis-induced rats. Colon morphology and damage were evaluated histologically; colonic tissues were used for mRNA analysis, using real-time PCR. Administration of both probiotics reduced the expression of proinflammatory cytokines tumor necrosis factor-alpha and IL-6 and increased the expression of mucin 2 in compared with colitis group and reduced the inflammatory response. These results provide additional support for the positive effect of probiotics in the gut and may shed light on the mechanism by which probiotic bacteria exert their action in an animal model.

Lancemaside A ameliorates colitis by inhibiting NF-kappaB activation in TNBS-induced colitis mice

PURPOSE

In a preliminary study, we found that lancemaside A, which is a main constituent of Codonopsis lanceolata used as an herbal medicine for inflammatory diseases, potently inhibits lipopolysaccharide (LPS)-stimulated, TLR-4-linked NF-kappaB activation of NF-kappaB luciferase reporter gene-transfected 293-hTLR4-hemagglutinin (HA) cells. Therefore, we investigated its inhibitory effect in 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis in mice.

METHODS

We measured the ability of lancemaside A to inhibit LPS-stimulated, TLR-4-linked NF-kappaB activation in human embryonic kidney (HEK) cells, as well as to inhibit colitis outcomes in TNBS-induced colitis in mice. We also measured levels of the inflammatory markers, interleukin (IL)-1beta, tumor necrosis factor (TNF)-alpha, and IL-6, and their transcription factor, NF-kappaB, in intestinal mucosa by enzyme-linked immunosorbent assay and immunoblotting.

RESULT

Intrarectal treatment of TNBS in mice caused colon shortening and also increased colonic expression of IL-1beta, IL-6, and TNF-alpha expression. Oral administration of lancemaside A (10 and 20 mg/kg), inhibited colon shortening and myeloperoxidase activity in TNBS-induced colitic mice and also decreased colonic expression of IL-1beta, IL-6, and TNF-alpha. Lancemaside A inhibited NF-kappaB activation induced by TNBS, as well as the expression of cyclooxygenase 2 and TLR-4. Lancemaside A also reduced the activity of intestinal bacterial beta-glucuronidase that was induced by TNBS.

CONCLUSIONS

Lancemaside A ameliorates colitis via inhibition of TLR-4-linked NF-kappaB activation.

The degradation of glycosaminoglycans by intestinal microflora deteriorates colitis in mice

The biosynthesis and modification of mucopolysaccharides and glycosaminoglycans (GAGs), secreted from gastrointestinal mucosal cells, are increased in colitis and influence the viability of the defense barrier. Therefore, to evaluate the role of GAG-degrading intestinal microflora during the progression of colitis, we investigated the degradation activity of intestinal bacterial GAG, cytotoxicity of GAGs and their metabolites, such as iduronic acid, D: -uronic acid or D: -glucuronic acid and D: -galactosamine or D: -glucosamine, against intestinal cells. We also tested their deteriorative effects against colitis. Colitis was induced using 2,4,6-trinitrobenzene sulfonic acid (TNBS) with and without antibiotics in mice. The TNBS treatment caused colon shortening, increased myeloperoxidase activity, induced IL-1beta, TNF-alpha, and IL-6 expression in the colon, activated NF-kappaB, and potentiated the GAG-degrading activities of intestinal microflora. The antibiotic treatment inhibited colon shortening, decreased myeloperoxidase activity, and reduced proinflammatory cytokine expression, NF-kappaB activation, and GAG degradation, induced by TNBS. Among the GAG metabolites, d-glucosamine and d-galactosamine showed cytotoxicity against intestinal cells, Caco-2 and IEC-18 cells, synergistically deteriorated the cytotoxicity of TNBS as well as the TNBS-induced colitis in mice. Based on these findings, intestinal microflora may degrade GAGs in colitis, their metabolites deteriorate the progress of colitis and antibiotics ameliorate the colitis by the inhibition of GAG-degrading bacterial growth.

Lactobacillus suntoryeus inhibits pro-inflammatory cytokine expression and TLR-4-linked NF-kappaB activation in experimental colitis

OBJECTIVE

Lactic acid bacteria (LAB) can improve disturbances of indigenous microflora as well as inflammatory bowel diseases (IBD) such as ulcerative colitis and Crohn's disease. We examined the anticolitic effect of Lactobacillus suntoryeus HY7801, which inhibited toll-like receptor (TLR)-4-linked NF-kappaB activation in human embryonic kidney (HEK) cells, in 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitic mice.

MATERIALS AND METHODS

We measured the ability of commercial and intestinal LAB to inhibit lipopolysaccharide (LPS)-stimulated, TLR-4-linked NF-kappaB activation in HEK cells, as well as to inhibit colitis outcomes in TNBS-induced colitic mice. We also measured levels of the inflammatory markers, interleukin (IL)-1beta, tumor necrosis factor (TNF)-alpha, and IL-6, and their transcription factor, NF-kappaB, in intestinal mucosa by enzyme-linked immunosorbent assay and immunoblotting.

RESULTS AND DISCUSSION

LAB inhibited TLR-4-linked NF-kappaB activation, and L. suntoryeus HY7801 was the most potent inhibitor. Intrarectal treatment of TNBS in mice caused colon shortening and also increased colonic expression of IL-1beta, IL-6, and TNF-alpha expression. However, oral administration of Lactobacillus HY7801 (100 mg/kg) inhibited colon shortening (p < 0.001) and myeloperoxidase activity in TNBS-induced colitic mice (p < 0.0002) and also decreased colonic expression of IL - 1beta (p < 0.003), IL-6 (p < 0.0001), and TNF-alpha (p < 0.0001). Lactobacillus HY7801 inhibited the NF-kappaB activation and TLR-4 expression induced by TNBS, as well as the expression of cyclooxygenase 2. Lactobacillus HY7801 also reduced the activity of intestinal bacterial glycosaminoglycan degradation and beta-glucuronidase induced by TNBS.

CONCLUSION

L. suntoryeus HY7801 can improve colitis via the inhibition of TLR-4-linked NF-kappaB activation.

Intestinal macrophage/epithelial cell-derived CCL11/eotaxin-1 mediates eosinophil recruitment and function in pediatric ulcerative colitis

Clinical studies have demonstrated a link between the eosinophil-selective chemokines, eotaxins (eotaxin-1/CCL11 and eotaxin-2/CCL24), eosinophils, and the inflammatory bowel diseases, Crohn's disease and ulcerative colitis (UC). However, the cellular source and individual contribution of the eotaxins to colonic eosinophilic accumulation in inflammatory bowel diseases remain unclear. In this study we demonstrate, by gene array and quantitative PCR, elevated levels of eotaxin-1 mRNA in the rectosigmoid colon of pediatric UC patients. We show that elevated levels of eotaxin-1 mRNA positively correlated with rectosigmoid eosinophil numbers. Further, colonic eosinophils appeared to be degranulating, and the levels positively correlated with disease severity. Using the dextran sodium sulfate (DSS)-induced intestinal epithelial injury model, we show that DSS treatment of mice strongly induced colonic eotaxin-1 and eotaxin-2 expression and eosinophil levels. Analysis of eosinophil-deficient mice defined an effector role for eosinophils in disease pathology. DSS treatment of eotaxin-2(-/-) and eotaxin-1/2(-/-) mice demonstrated that eosinophil recruitment was dependent on eotaxin-1. In situ and immunofluorescence analysis-identified eotaxin-1 expression was restricted to intestinal F4/80(+)CD11b(+) macrophages in DSS-induced epithelial injury and to CD68(+) intestinal macrophages and the basolateral compartment of intestinal epithelial cells in pediatric UC. These data demonstrate that intestinal macrophage and epithelial cell-derived eotaxin-1 plays a critical role in the regulation of eosinophil recruitment in colonic eosinophilic disease such as pediatric UC and provides a basis for targeting the eosinophil/eotaxin-1 axis in UC.

Lymphocyte homing and its role in the pathogenesis of IBD

Inflammatory bowel disease (IBD) is an idiopathic disorder of chronic inflammation of the gastrointestinal tract. Experimental models of IBD and results from human genomewide linkage studies suggest that the primary defect that leads to IBD is an inappropriate mucosal immune response to normal intestinal microbes. Genetic alterations not only confer increased susceptibility to IBD but also appear to determine the nature and location of the intestinal inflammation, as is evident in patients with genetic alterations of NOD2 and their susceptibility for ileal Crohn's disease. IBD has traditionally been classified into 2 subtypes, namely, ulcerative colitis (UC) and Crohn's disease (CD), based on histological appearance and anatomical distribution. However, an increasing body of data supports the concept that IBD is an umbrella diagnosis encompassing a variety of disorders with distinct genetic, microbial, and environmental determinants that cluster either into a UC or CD phenotype. The shared common pathway is uncontrolled intestinal inflammation. A key element in the pathogenesis of intestinal inflammation in both UC and CD is increased leukocyte recruitment from the circulation, and this provides a potential target for pharmaceutical inhibition. In this article we review the current understanding of the molecules that determine leukocyte trafficking to the gut and highlight opportunities where their inhibition could be exploited to treat IBD.(Inflamm Bowel Dis 2008).

Gastroduodenitis associated with ulcerative colitis

BACKGROUND

Ulcerative colitis (UC) is regarded as confined to the colorectum; however, there are several case reports showing upper gastrointestinal involvement. The aim of this study was to examine the prevalence and characteristics of gastroduodenitis associated with UC (GDUC).

METHODS

Esophagogastroduodenoscopy with biopsies was prospectively performed on 250 UC patients (134 men, 116 women; mean age, 42 years; 162 with colectomy, 163 with pancolitis). Criteria for GDUC were created on the basis of endoscopic and histological comparisons with non-UC controls, and the prevalence and characteristics were statistically analyzed.

RESULTS

GDUC was defined endoscopically as friable mucosa (erosive or ulcerative mucosa with contact or spontaneous bleeding), granular mucosa (multiple white spots almost without a red halo), or, conditionally, multiple aphthae (multiple white spots surrounded by a red halo, clinically excluding other disorders such as Crohn's disease). The prevalence of GDUC was 19/250 (7.6%). The clinical characteristics included more extensive colitis, lower dose of prednisolone, higher prevalence of pouchitis, and longer postoperative period. In our population, the presence of pancolitis and a lower dose of prednisolone were significant risk factors for developing GDUC in multivariate analysis.

CONCLUSIONS

The high prevalence of GDUC suggests that the gut inflammatory reaction in UC may not be restricted to the large intestine. Administered steroids might conceal GDUC, and more aggressive UC such as active pancolitis may be related to the development of GDUC.

Lactic acid bacteria inhibit proinflammatory cytokine expression and bacterial glycosaminoglycan degradation activity in dextran sulfate sodium-induced colitic mice

To evaluate the effect of lactic acid bacteria (LAB) in inflammatory bowel diseases (IBD), inhibitory effect of several LAB isolated from intestinal microflora and commercial probiotics against NO production of lipopolysaccharide (LPS)-stimulated RAW264.7 cells was measured and anti-inflammatory effect of NO production-inhibitory LAB, Lactobacillus plantarum HY115 and L. brevis HY7401, in dextran sulfate sodium (DSS)-induced experimental colitic mice was investigated. The oral administration of the LAB to mice inhibited colon shortening and myeloperoxidase productivity in DSS-induced colitic mice. These LABs repressed the mRNA expressions of IL-1beta, TNF-alpha and IFN-gamma, as well as the protein expressions of IL-1beta and IL-6 proteins in the colon. The activation of the transcription factor, NF-kB, induced by DSS, was also inhibited by LAB. The administration of LAB reduced the degradation activities of chondroitin sulfate and hyaluronic acid of intestinal bacteria, induced by DSS, of which could induce the cytotoxic metabolites against intestinal cells. These findings suggest that NO-inhibitory LAB against LPS-stimulated RAW264.7 cells may improve colitis by the regulation of the inflammatory cytokine expression via the activation of transcription factor NF-kB as well as GAGs-degrading intestinal microflora.

Immune dysfunction in inflammatory bowel disease

Ulcerative colitis (UC) and Crohn's disease (CD) are idiopathic inflammatory bowel diseases (IBDs) that are characterized by chronic periods of exacerbation and remission. Research into the immunopathogenesis of IBD adds support to the theory that the disease results from a dysfunctional regulation of the immune system that leads to the polarization of intestinal immune cells toward a Th1 (T helper) response. The immunologic factors that mediate alterations in intestinal homeostasis and the development of intestinal mucosal inflammation have been at the forefront of IBD research. Cytokines, which are important regulators of leukocyte trafficking and apoptotic cell death, have emerged as essential immune molecules in the pathogenesis of IBD. In this study, recent advances in the understanding of the dynamism of cytokines and the consequences for mucosal immunity and inflammation in IBD are discussed. Furthermore, this study highlights the potential use of cytokines, anti-cytokine antibodies, and cytokine-related biologic therapies as novel targets for the treatment of IBD.

Simvastatin down regulates mRNA expression of RANTES and CCR5 in posttransplant renal recipients with hyperlipidemia

Chemokines and hyperlipidemia are involved in the mechanism of chronic allograft nephropathy (CAN). In this study, the mRNA expression of RANTES and its receptor CCR5 on peripheral blood mononuclear cells were measured in renal transplant recipients with hyperlipidemia, and the effect of simvastatin treatment observed to investigate the mechanism and prevention of CAN. Sixty recipients selected from 167 renal transplant recipients were divided into two groups: group A without hyperlipidemia (n = 30) and group B with hyperlipidemia (n = 30). The control group consisted of 30 healthy volunteers. The recipients in group B were treated with simvastatin for 3 months. We estimated serum lipid levels and mRNA expressions of RANTES and CCR5. The mRNA expressions of RANTES and CCR5 were significantly higher in renal transplant recipients compared with controls. The expressions were much higher in group B than in group A patients. In group B patients, serum lipid levels decreased dramatically after simvastatin treatment. Meanwhile, the mRNA expressions of RANTES and CCR5 were reduced significantly after 1.5 months of simvastatin treatment to a level significantly lower than that in group A after 3 months of treatment. The increased expressions of RANTES and CCR5 mRNAs in renal transplant recipients with hyperlipidemia might be involved in CAN due to hyperlipidemia. Simvastatin seemed to reduce the chemokine transcripts in renal recipients with hyperlipidemia.

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Protein microarray analysis of disease activity in pediatric inflammatory bowel disease demonstrates elevated serum PLGF, IL-7, TGF-beta1, and IL-12p40 levels in Crohn's disease and ulcerative colitis patients in remission versus active disease

OBJECTIVES

Cytokines and growth factors play a major role in the dysregulated immune response in inflammatory bowel disease (IBD). We hypothesized that significant differences exist between the serum cytokine and growth factor profiles of pediatric IBD patients with active disease (AD) and those in remission, and that levels of some of these soluble mediators may be used to define regulators in IBD and determine disease activity.

METHODS

Eighty-eight consecutive patients with confirmed Crohn's disease (CD) and ulcerative colitis (UC) seen at the Duke Children's Hospital were prospectively enrolled and a serum sample was obtained. Data were recorded at the time of serum collection to calculate disease activity indices. The relative expression of 78 cytokines, growth factors, and soluble receptors was determined using proprietary antibody-based protein microarrays amplified by rolling circle amplification. SPSS 8 (SPSS Inc., Chicago, IL) was used to compare protein profiles for CD and UC patients in clinical remission (CR) versus AD.

RESULTS

Sixty-five CD patients and 23 UC patients were enrolled. Forty-one CD patients had available samples and PCDAI results. Twenty-two patients were in remission PCDAI < or = 12.5 (median 5), 19 patients had disease activity >15 (median 30). Univariate analysis revealed that PLGF, IL-7, IL-12p40, and TGF-beta1 cytokine levels were significantly elevated for patients in CR versus AD (p < 0.01). Twelve UC serum samples had Seo/Truelove Witt AI for analysis. Five patients were in remission by TW AI and Seo AI < or =110 and 7 patients had active mild-to-severe disease by TW and Seo AI >110. Only one cytokine, IL12p40, showed significance between CR versus AD (p < 0.02).

CONCLUSIONS

Surprisingly, we found no differences in circulating levels of proinflammatory cytokines but found that pediatric IBD patients in remission compared to those with AD had higher levels of specific circulating cytokines, including the regulatory cytokines IL-12p40 and TGF-beta1. It may be that these cytokines directly regulate intestinal inflammation in IBD or reflect the activity of T regulatory cells in negatively regulating the inflammatory response. Further studies will be needed to validate our results to define the molecular pathways involved in the intestinal immune response in man.