G protein-coupled receptor 55 (GPR55) expresses differently in patients with Crohn’s disease and ulcerative colitis

Aim: To investigate the levels of G protein-coupled receptor 55 (GPR55) expression in colonic tissue of inflammatory bowel disease (IBD) patients and healthy controls, and its potential implication in IBD treatment.

Methods: Fifty patients were enrolled in our prospective study: n?=?21 with Crohn’s disease (CD) and n?=?16 with ulcerative colitis (UC); 19 women and 18 men. Control consisted of 13 non-IBD patients. In each subject, two biopsies were taken from different colonic locations. In IBD patients, biopsies both from endoscopically inflamed and non-inflamed areas were drawn and the development of inflammation confirmed in histopathological examination. GPR55 mRNA and protein expression were measured using real-time PCR and Western blot, respectively.

Results: GPR55 expression at mRNA and protein level was detected in all samples tested. The level of GPR55 mRNA expression in non-inflamed colonic areas was comparable in all analyzed groups (p?=?.2438). However, in the inflamed tissues GPR55 mRNA expression was statistically significantly (p?<?.0001) higher (6.9 fold) in CD patients compared to UC. Moreover, CD patients manifested higher (12.5 fold) GPR55 mRNA expression in inflamed compared with non-inflamed colonic tissues (p?<?.0001). Although no significant differences were stated, GPR55 protein level tends to decrease in IBD as compared to control.

Conclusions: Different patterns of GPR55 expression at mRNA level were observed in IBD patients. We speculate that GPR55 is crucial for the mucosal inflammatory processes in IBD, particularly in CD and its expression may affect disease severity, and response to treatment. The GPR55 receptors may become an attractive target for novel therapeutic strategies in IBD.     

Immunohistochemical localization of vascular endothelial growth factor in colonic mucosa of patients with inflammatory bowel disease

BACKGROUND/AIMS: Significantly enhanced serum levels of VEGF (vascular endothelial growth factor) were found in patients with inflammatory bowel disease. Peripheral blood mononuclear cells have been identified as one of the origins of the circulating VEGF. The present investigation examines the localization of VEGF at the site of inflammation in colonic mucosa of patients with Crohn's disease and ulcerative colitis. METHODOLOGY: Immunohistochemical localization of VEGF and immunostaining for leukocytes were performed in colonic mucosal biopsies of 41 patients with Crohn's disease, 26 patients with ulcerative colitis and normal mucosal specimens of 5 patients with irritable bowel syndrome. Measurement of immunohistochemical staining for VEGF and for leukocytes within the epithelium and the lamina propria was performed separately by area morphometry using a computerized cell analysis system. RESULTS: In both patients with Crohn's disease and ulcerative colitis immunohistochemical staining for VEGF within the lamina propria of inflamed colonic mucosa was significantly higher compared with noninflamed mucosa (Crohn's disease: 4.26% vs. 0.07%, P < 0.001; ulcerative colitis: 3.68% vs. 0.32%, P = 0.001). There was a significant correlation between immunostaining for leukocytes and VEGF within the lamina propria in both patients with Crohn's disease (r = 0.73, P < 0.05)) and ulcerative colitis (r = 0.67, P < 0.05). In Crohn's disease immunostaining for VEGF within the epithelium was significantly higher in inflamed mucosa compared with noninflamed mucosa (9.85% vs. 0.63%, P < 0.001). In contrast, strong immunostaining for VEGF has been observed in the epithelium of noninflamed mucosa (7.60%, P < 0.003), as well as in inflamed mucosa of patients with active ulcerative colitis (9.68%, P < 0.002) compared with noninflamed mucosa of patients with inactive ulcerative colitis (1.39%). CONCLUSIONS: The present data indicate, that the increased VEGF expression within the epithelium and the interstitial accumulation of VEGF-producing leukocytes in inflamed mucosa may play an important role in the inflammatory mechanisms of Crohn's disease and ulcerative colitis.     

CCR5 expression in inflammatory bowel disease and its correlation with inflammatory cells and β-arrestin2 expression

Objective: To elucidate the correlation of expression of CC chemokine receptor 5 (CCR5) with degrees of inflammatory cells infiltration and expression of β-arrestin2 in biopsic intestinal mucosa of the patients with inflammatory bowel disease (IBD).

Methods: Paraffin sections were derived from 53 patients with active IBD, 26 patients with remissive IBD and 30 healthy people. Immunohistochemical envision two-step method was used to test the expression of CCR5 and β-arrestin2 in biopsic intestinal mucosa. HE and toluidine blue staining were used to detect the pathological cytological analysis and classification in lamina propria of colonic mucosa.

Results: The positive rate, strong positive rate and immunohistochemical score of CCR5 expression in active IBD were significantly higher than that in normal controls and remissive IBD (p?<?.05). CCR5 expression had no obvious correlation with clinical severity, lesion distribution and endoscopic classification of active IBD. Neutrophils, eosinophils and lymphocytes in active IBD were significantly higher than that in normal controls and remissive IBD (p?<?.05), while the lymphocyte grade had a positive correlation with CCR5 expression (p?=?.042, r?=?.286). Mastocytes in active IBD, remissive IBD and normal controls had no obvious difference (p?>?.05). β-arrestin2 expression was significantly lower in active IBD than that in remissive IBD and normal controls, and it had a negative correlation with CCR5 expression (p?=?.01, r?=??.247).

Conclusions: CCR5 is highly expressed in active IBD, and it has positive correlation with lymphocyte grade and negative correlation with expression of β-arrestin2.     

Expression of platelet-derived endothelial cell growth factor and vascular endothelial growth factor in hepatocellular carcinoma and portal vein tumor thrombus

Purpose: Both platelet-derived endothelial cell growth factor (PD-ECGF) and vascular endothelial growth factor (VEGF) are known to promote the development of new blood vessels, which are fundamental to tumor growth and metastasis. We aimed at evaluating the gene expression of PD-ECGF and VEGF in hepatocellular carcinoma (HCC) and portal vein tumor thrombus (PVTT). Patients and methods: Surgical specimens (28 HCC, 28 nontumorous liver tissues and 18 PVTT) were studied by Northern blot analysis. The levels of PD-ECGF mRNA and VEGF mRNA expression were measured by densitometric scanning of the autoradiographs, and they were normalized to the level of expression of an internal control (glyceraldehyde-phosphate dehydrogenase) mRNA. Results: The expression rates of PD-ECGF mRNA in PVTT, HCC and nontumorous liver tissues were 77.8% (14/18), 67.9% (19/28) and 35.7% (10/28), being 88.9% (16/18), 75.0% (21/28) and 17.9% (5/28) respectively for VEGF mRNA. The expressions of PD-ECGF mRNA and VEGF mRNA were higher in HCC with PVTT than when PVTT was absent (P < 0.05). The PVTT was more often seen in patients with positive expression of both PD-ECGF mRNA and VEGF mRNA in HCC than in patients who were positive for only one of these factors or negative for both (P < 0.05). Conclusion: Both PD-ECGF and VEGF correlated well with the formation of PVTT of HCC. Received: 20 June 1999 / Accepted: 20 July 1999     

Human tissue transglutaminase ELISA and an old study: a revision of the blood donor screening study for coeliac disease in the USA

Objective. Growing evidence indicates that innate immunity, including toll-like receptor (TLR) signalling, plays a role in inflammatory bowel disease (IBD). This may also apply in the case of TLR-8, which has recently been shown to reverse the immunosuppressive function of regulatory T cells. However, the role of TLR-8 in IBD is currently unknown, and therefore we investigated the expression of TLR-8 and its natural antagonist, Tollip, in normal and inflamed human gut, and examined whether the receptor is functionally active. Methods. TLR-8 and Tollip mRNA expression were measured in colonic epithelial cells (CEC) and lamina propria mononuclear cells (LPMNC) by quantitative polymerase chain reaction. TLR-8 protein expression was visualized in whole biopsy specimens by indirect immunofluorescence microscopy. Cellular localization of TLR-8 protein was assessed by immuno-electron microscopy. IL-8 secretion was measured by ELISA after stimulation with TLR-8 ligand. Results. TLR-8 mRNA and protein expression were substantially up-regulated in CEC from inflamed mucosa from patients with ulcerative colitis (～350-fold, p<0.01) and Crohn's disease (～45-fold, p<0.05) compared to controls. TLR-8 proteins resided on the luminal surface membrane and in intracellular organelles. Tollip was not increased in CEC from IBD patients. CEC from normal mucosa responded to TLR-8 stimulation by secreting IL-8. TLR-8 was expressed only on the mRNA level in LPMNC with no differences between IBD patients and controls. Conclusion. Expression of TLR-8, but not Tollip, is highly up-regulated in the colonic epithelium from patients with active IBD. Since the receptor is functionally active, our data suggest that TLR-8 signalling is important in the pathogenesis of IBD.     

Specific Enhanced Expression of Platelet-Derived Endothelial Cell Growth Factor in Submucosa of Human Colorectal Cancer

PURPOSE Platelet-derived endothelial cell growth factor, identified to be an angiogenic factor, has been implicated in metastases of colorectal cancer. This study aimed to clarify the role and localization of platelet-derived endothelial cell growth factor associated with human colorectal cancer invasion.METHODS Thirty-two patients with colorectal cancer who had undergone surgery were analyzed. Platelet-derived endothelial cell growth factor enzyme activities in the colorectal cancer specimens were measured. Cells that expressed platelet-derived endothelial cell growth factor were identified and localized by immunohistochemical analysis with anti-human platelet-derived endothelial cell growth factor antibody and by in situ hybridization with specific RNA probe.RESULTS Platelet-derived endothelial cell growth factor enzyme activity increased significantly in cancer tissues compared with normal colonic mucosa at various distances from the cancer. Immunohistochemical analysis and in situ hybridization demonstrated platelet-derived endothelial cell growth factor expression in stromal macrophages and fibroblasts located in cancer tissues and surrounding noncancerous tissues, although the tumor cells and normal colonic mucosa were negative. The value of platelet-derived endothelial cell growth factor expression was highest at the border of the colorectal cancer (35.3 ± 8.9 percent), followed by the cancer nest (15.2 ± 9.2 percent) and normal mucosa (7.7 ± 3.4 percent). In the border area, the highest value of platelet-derived endothelial cell growth factor expression was observed in the submucosa (35.3 ± 8.9 percent), followed by the muscular propria (21.9 ± 7.7 percent) and the subserosa (14.9 ± 5.5 percent).CONCLUSIONS Stromal macrophages and fibroblasts are responsible for elevated platelet-derived endothelial cell growth factor activity in colorectal cancer. The significance of enhanced expression of platelet-derived endothelial cell growth factor in the submucosa at the cancer border remains unclear. Cancer stroma may be an important factor for cancer angiogenesis and may serve as a treatment target through specific modulation of angiogenic factors.Presented at the meeting of the Japan Surgical Society, Sendai, Japan, April 11 to 13, 2001.     

Upregulation of Reg 1alpha and GW112 in the epithelium of inflamed colonic mucosa

BACKGROUND AND AIMS: Colonic epithelium is involved in the regulation of intestinal function and mucosal immune responses, and its function is altered in inflammatory bowel disease (IBD). However, a comprehensive analysis of the genetic alterations in inflamed colonic epithelium is not available at present. The aim of our study was to detect genes that are preferentially expressed in inflamed colonic epithelia and clarify the biochemical responses of epithelial cells in inflamed colonic mucosa. METHODS: cDNA representation difference analysis was used to identify candidate genes selectively expressed in inflamed colonic epithelia. Selective expression of these genes in the epithelium of inflamed colonic mucosa, including IBD and non-IBD tissues, was examined by real time polymerase chain reaction and in situ hybridisation. The effect of cell confluence and inflammatory mediators on Reg 1alpha gene expression was examined using a colon cancer cell line (HT29). RESULTS: We identified seven candidate genes that were presumed to be upregulated in the inflamed colonic epithelium. Of these, Reg 1alpha and GW112 were the dominant species and expression of these genes was confined to the crypt epithelium. In vitro studies using a colonic epithelial cell line suggested that cell confluence regulates Reg 1alpha gene expression. CONCLUSIONS: Selective expression of Reg 1alpha and GW112 genes in the crypt epithelium of inflamed colonic mucosa suggests the important regulatory functions of these genes.     

Immunohistochemical study of intestinal eosinophils in inflammatory bowel disease

BACKGROUND: Eosinophil accumulation and activation are characteristic features of inflammation in allergic diseases and in host defense against parasites. GOALS: To investigate the involvement of eosinophils in inflamed and noninflamed mucosa of patients with inflammatory bowel disease (IBD). STUDY: Specimens of inflamed colonic mucosa from 15 patients with ulcerative colitis (UC) and inflamed and noninflamed colonic mucosa from 15 patients with Crohn's disease (CD) were submitted to histologic and immunohistochemical studies. Twelve patients with irritable bowel syndrome were studied as controls. Sirius red was used to label eosinophils in tissue. EG1, EG2, and anti-hIL-5 were used as primary antibodies in an indirect alkaline phosphatase-labeled immunostaining protocol. Both positive and negative lamina propria cells were assessed by a quantitative grading system and the results expressed as cell numbers per mm. RESULTS: Increased proportions of eosinophils stained with Sirius red, EG1, EG2, and anti-hIL-5+ cells were found in the colon of patients with UC and in inflamed and noninflamed colon of CD patients as compared with controls. Crohn's disease patients showed increased proportions of EG1+ and EG2+ cells as compared with those with UC. Increased proportions of IL-5+ cells were detected in UC patients as compared with those with CD. CONCLUSION: Quantitative eosinophil alterations and IL-5+ cells may indicate enhanced cellular activation with degranulation, which is implicated in the pathogenesis of IBD. Increase in IL-5+ cells may reflect a predominant local Th2 response in UC as compared with CD.     

CD99 refers to the activity of inflammatory bowel disease

Background: Inflammatory bowel disease (IBD), composed of Crohn’s disease (CD) and ulcerative colitis (UC), is an inflammatory autoimmune disease. CD99 has been reported to participate in migration of leukocytes and T cell activation. However, the roles of CD99 in IBD are obscure.

Materials and methods: CD99 expression was examined in peripheral blood mononuclear cells (PBMCs) and inflamed mucosa from IBD patients by qRT-PCR. Serum TNF-α and IL-17A levels were detected by ELISA. Correlations of CD99 expression with TNF-α, IL-17A, Crohn’s disease activity index (CDAI), simple endoscopic score for CD (SES-CD), Mayo index, and Truelove grading were performed by Pearson’s correlation.

Results: CD99 expression was increased in PBMCs and inflamed mucosa from active CD and UC patients, and CD99 expression was also increased in the inflamed mucosa compared with unaffected control from the same patients. Serum TNF-α and IL-17A levels were increased in active CD or UC patients, and positively correlated with CD99 expression in PBMCs (CD: r?=?.402, p?=?.009; r?=?.350, p?=?.025. UC: r?=?.289, p?=?.028; r?=?.322, p?=?.014). Moreover, CD99 expression in inflamed mucosa was correlated with CDAI, SES-CD, Mayo index, and Truelove grading (r?=?.410, p?=?.012; r?=?.341, p?=?.005; r?=?.366, p?=?.002; r?=?.312, p?=?.011).

Conclusion: CD99 expression is increased in patients with active IBD, and positively correlated with disease activity. Therefore, CD99 expression can be used as an index to evaluate the activity of IBD.     

Impaired Synthesis or Cellular Storage of Norepinephrine, Dopamine, and 5-Hydroxytryptamine in Human Inflammatory Bowel Disease

The present study was aimed at evaluating the extent of dysfunction of the enteroendocrine and enteric nervous system, as indicated by changes in tissue levels of monoamines (dopamine, DA; norepinephrine, NE; 5-hydroxytryptamine, 5-HT) and their precursors and metabolites in the colonic mucosa of patients afflicted with ulcerative colitis (UC, N = 21) and Crohn's disease (CD, N = 22). In CD, but not in UC, NE tissue levels in both the noninflamed and inflamed colonic mucosa were markedly lower than in control subjects (N = 16). In the inflamed mucosa of CD and in UC patients levels of l-DOPA were twice those in controls. DA levels in the inflamed mucosa of CD and UC patients were markedly lower than in controls. This resulted in significant reductions in DA/l-DOPA tissue ratios, a rough measure of l-amino acid decarboxylase activity. 5-HT levels in the inflamed mucosa of CD and UC patients were markedly lower than in controls. In conclusion, intestinal cellular structures responsible for the synthesis and storage of DA, NE, and 5-HT may have been affected by the associated inflammatory process in both CD and UC.     

Methylation patterns in dysplasia in inflammatory bowel disease patients

Abstract

Background and aims: Inflammatory Bowel Disease (IBD) with colonic involvement increases colorectal cancer risk. However, the distinction between IBD related and sporadic dysplasia in IBD patients is difficult. Some data favors the importance of abnormal DNA methylation in IBD-related carcinogenesis. We aimed to define methylation patterns in patients with colonic cancer or dysplasia diagnosis following an IBD diagnosis.

Methods: Multicentric cross-sectional study-91 samples from colonic mucosa with/without dysplasia from 9 patients with IBD-related dysplasia/cancer and 26 patients with IBD and sporadic dysplasia/cancer were included. Methylation patterns of CpG islands in the promoter regions of 67 genes were studied by Methylation-specific Multiplex Ligation-dependent Probe Amplification.

Results: Mean age at IBD diagnosis: 42?±?16?years;at dysplasia diagnosis: 56?±?14?years. Twenty-ninepatients had ulcerative colitis. Twenty-five patients had at least 1 lesion endoscopically described as adenoma-like, 4 at least 1 non-adenoma like, 3 had cancer and 3 had dysplasia in flat mucosa. No patient had both adenoma-like and non-adenoma-like lesions. Patients with an IBD-related lesion were significantly younger at IBD diagnosis (p?=?.003) and at dysplasia/cancer diagnosis (p?=?.039). Promoter methylation of IGF2, RARB, ESR1, CHFR, CDH13, WT1, GATA5, WIF1genes was significantly associated to dysplasia/cancer; methylation of MSH6, TIMP3 was significantly associated to IBD-related dysplasia/cancer. Promoter methylation of MSH6, MSH3, RUNX3, CRABP1, TP73, RARB, CDH13, PAX5, WT1, THBS1, TP53, SFRP1, WIF1, APAF1, BCL2 genes was significantly associated to active IBD.

Conclusions: Methylation analysis, namely of MSH6, may contribute to the classification of dysplastic lesions in IBD– to be further tested in prospective studies.     

Activation of NF-κB in intestinal epithelial cells by<Emphasis Type="Italic"> E. coli</Emphasis> strains isolated from the colonic mucosa of IBD patients

Background and aims The involvement of bacteria in the pathogenesis of inflammatory bowel disease has been discussed for several years. In this study we evaluated the ability of E. coli isolates from inflamed and noninflamed colonic mucosa to activate NF-B.Materials and methods Fifteen bacterial strains from inflamed and six from noninflamed colonic tissues from IBD patients. Their ability to induce NF-B activation was examined in vitro by gel-shift assays. The activation of the TNF- promoter was determined by reporter gene assays. Bacterial isolates were characterized by invasion assays, electron microscopy, and PCR.Results Four of 15 E. coli bacterial isolates from inflamed IBD tissues induced NF-B activity in intestinal epithelial cells as determined by gel-shift assays. NF-B activation was only seen with living bacteria but not with heat-inactivated cells. Isolates from noninflamed tissues and a wild-type E. coli control strain induced a weaker or no activation. Reporter gene assays with a construct comprising a luciferase gene driven by the TNF- promoter revealed that isolates from Crohns disease patients induced a stronger activation of the TNF- gene than isolates from ulcerative colitis patients. The isolated bacteria invaded HT-29 cells, although typical virulence genes for enteropathogenic, enterhemorrhagic, or enteroinvasive E. coli, i.e., eae, tir, EspA, Per (A-C), ipaC, were not detected in these cells. Bacterial invasion was additionally confirmed by electron microscopy examination.Conclusion Our results indicate that E. coli strains can be found in the mucosa of some IBD patients which are able to activate NF-B similar to known pathogenic strains. The absence of several virulence genes in these cells suggests that they are members of the luminal flora which acquire as yet unidentified virulence determinants and are therefore involved in the pathophysiology of IBD.     

Changes in the expression and distribution of the inducible and endothelial nitric oxide synthase in mucosal biopsy specimens of inflammatory bowel disease

Objective The role of nitric oxide (NO) in the pathophysiology of inflammatory bowel disease (IBD) is controversial. The aim of this study was to investigate the expression and localization of nitric oxide synthase isoforms (iNOS, eNOS) in IBD colonic mucosa. Material and methods Forty-four patients with IBD (24 ulcerative colitis (UC), 20 Crohn's disease (CD) and 16 controls) were investigated by colonoscopy. iNOS and eNOS in tissue sections was demonstrated by histochemistry (NADPH-diaphorase reaction) and immunohistochemistry. Cell type analysis and quantitative assessment of the iNOS immunoreactive (IR) cells and densitometry of iNOS in immunoblots were also performed. Results iNOS-IR cells were significantly numerous in inflamed mucosa of UC (64±4 cells/mm²) than in CD (4±2 cells/mm²). iNOS-IR/CD15-IR cells showed significant elevation in inflamed (i) versus uninflamed (u) UC mucosa (UC_u 8±3%, UC_i 85±10%) In CD, the percentage of iNOS-IR/CD68-IR cells was lower in inflamed sites (CD_u 23±8%, CD_i 4±3%). Immunoblot of biopsies revealed significant elevation of iNOS in active UC compared with uninflamed sites, whereas in CD no significant changes were detected. Differences were observed in eNOS and endothelial marker CD31 immunoreactivity. In patients with UC and in controls the ratios of eNOS/CD31-IR vessels were 82.3% and 92.0% respectively, whereas in CD the ratio was 8.3% with a concomitantly significant increase of CD31-IR vessels. The distribution and morphological characteristics of the NOS-IR inflammatory cells and endothelia were similar to those showing NADPH-diaphorase reactivity. Conclusions Differences observed in the expression and distribution of NOS isoforms in immune and endothelial cells may contribute to better understanding of the structural and physiological changes in UC and CD.     

Anti-inflammatory effects of pancreatitis associated protein in inflammatory bowel disease

BACKGROUND AND AIMS: Increased pancreatitis associated protein (PAP) mRNA has been reported in active inflammatory bowel disease (IBD). The aims of the current study were to characterise PAP production in IBD and the effects of PAP on inflammation. PATIENTS AND METHODS: Serum PAP levels were determined in healthy controls (n = 29), inflammatory controls (n = 14), and IBD patients (n = 171). Ex vivo PAP secretion in intestinal tissue was measured in 56 IBD patients and 13 healthy controls. Cellular origin of PAP was determined by immunohistochemistry. The effects of exogenous PAP on nuclear factor kappaB (NFkappaB) activation, proinflammatory cytokine production, and endothelial adhesion molecule expression were also analysed ex vivo. RESULTS: Patients with active IBD had increased serum PAP levels compared with controls, and these levels correlated with clinical and endoscopic disease severity. Ex vivo intestinal PAP synthesis was increased in active IBD and correlated with endoscopic and histological severity of inflammatory lesions. PAP localised to colonic Paneth cells. Incubation of mucosa from active Crohn's disease with PAP dose dependently reduced proinflammatory cytokines secretion. PAP prevented TNF-alpha induced NFkappaB activation in monocytic, epithelial, and endothelial cells and reduced proinflammatory cytokine mRNA levels and adhesion molecule expression. CONCLUSIONS: PAP is synthesised by Paneth cells and is overexpressed in colonic tissue of active IBD. PAP inhibits NFkappaB activation and downregulates cytokine production and adhesion molecule expression in inflamed tissue. It may represent an anti-inflammatory mechanism and new therapeutic strategy in IBD.     

Elevated levels of serum-soluble triggering receptor expressed on myeloid cells-1 in patients with IBD do not correlate with intestinal TREM-1 mRNA expression and endoscopic disease activity

Background & aimsTriggering receptor expressed on myeloid cells-1 (TREM-1) is a potent amplifier of pro-inflammatory responses. We have previously demonstrated a substantial increase in TREM-1-expressing macrophages in the inflamed intestinal mucosa of patients with inflammatory bowel diseases (IBD). TREM-1 is also produced as a soluble receptor (sTREM-1). Here, we aimed to determine whether serum sTREM-1 could be used as a surrogate marker of disease activity in patients with IBD.MethodsIntestinal biopsies and concurrently collected sera from patients with Crohn's disease (CD) and Ulcerative colitis (UC) enrolled in the Swiss IBD cohort study were analyzed for intestinal TREM-1 mRNA and serum sTREM-1 expression. TREM-1 mRNA and sTREM-1 were correlated with the endoscopically determined disease activity. Serum sTREM-1 and TREM-1 mRNA expression levels were further determined in sera and colonic tissues collected at various time-points post disease induction in an experimental mouse model of colitis and correlated with disease activity.ResultsExpression of TREM-1 mRNA was upregulated in intestinal biopsies from patients with active disease but not in patients with quiescent disease. Serum sTREM-1 was elevated in IBD patients compared to normal controls. No substantial differences in sTREM-1 expression levels were found in patients with active versus quiescent disease. In colitic mice, colonic TREM-1 mRNA and serum sTREM-1 were also upregulated. While colonic TREM-1 mRNA expression levels correlated with disease activity, augmented serum sTREM-1 in fact associated with a milder course of disease.ConclusionsAnalysis of sTREM-1 as a surrogate marker of disease activity in patients with IBD warrants caution.     

Interleukin-18 is increased only in a minority of patients with active Crohn’s disease

Background and aims It has been suggested that Crohn’s Disease (CD) is associated with an elevated T helper 1 response as manifested by increased production of interleukin-18 (IL-18). Local concentrations of neutralizing IL-18 binding proteins (IL-18bp) may counteract biological functions of mature IL-18 in mucosal inflammation. Therefore, we investigated the IL-18/IL-18bp system in a large group of patients with active inflammatory bowel disease (IBD) to identify patients that could respond theoretically to IL-18 neutralizing treatment strategies. Patient/methods IL-18 and IL-18bp messenger RNA (mRNA) expression in colonic mucosa from patients with active CD (n = 72), active ulcerative colitis (UC; n = 32), and non-IBD controls (infectious colitis or diverticulitis; n = 19) and normal, non-diseased controls (n = 20) were measured by reverse-transcribed real-time polymerase chain reaction. Mature IL-18 protein and IL-18bp expression in inflamed mucosa were assessed by Western blotting. Results/findings Although IL-18 mRNA was increased in some patients with CD, the increase was not statistically significant. Densitometric evaluation of IL-18/α-actin ratio in patients with active CD (n = 20) and patients with UC (n = 10) demonstrated an increased ratio of IL-18 protein in CD when compared to UC (1.04 vs 0.72 [median]). On closer inspections, only 7/20 CD patients had an increased IL-18 protein expression in inflamed areas compared to noninflamed mucosa. Interpretation/conclusion IL-18 expression in active CD is heterogeneous, only a minority of patients expresses elevated levels. Further treatment strategies targeting IL-18 expression in active CD should be concentrated on this subgroup of patients.     

Increased expression of VEGF and CD146 in patients with inflammatory bowel disease

BACKGROUND: Angiogenesis has been suggested as an integral part of inflammatory bowel disease pathology. Vascular endothelial growth factor has long been considered to play a central, specific role in angiogenesis. Endothelial junction adhesion molecules, such as CD146, have recently been suggested to play a potent role in angiogenesis. CD34 is expressed on vascular endothelium, and it has been reported to be upregulated on endothelium in IBD. We investigated the expression of tissue vascular endothelial growth factor, CD34 and CD146 in the inflamed mucosa of patients with active inflammatory bowel disease compared with no inflamed mucosa of healthy controls. METHODS: Forty-two IBD patients [23 ulcerative colitis, 19 Crohn's disease] and ten healthy controls were included in the study. In colonoscopically obtained biopsies, CD34, CD146 and vascular endothelial growth factor expression were evaluated by immunohistochemistry. RESULTS: Vascular endothelial growth factor was detected in the mucosa of all groups, and its expression was significantly higher in both Crohn's disease and ulcerative colitis compared with controls (p<0.05). Immunohistochemical staining for CD146 in the inflamed mucosa was significantly higher in both Crohn's disease and ulcerative colitis compared with controls (p=0.002). A trend of higher CD34 expression in Crohn's disease and ulcerative colitis compared with controls was also found, but the difference among the three groups was not statistically significant (p=0.09). CONCLUSIONS: Inflamed mucosa of patients with active Crohn's disease and ulcerative colitis showed a markedly enhanced expression of VEGF and CD146, than normal mucosa of controls, indicating a possible role of angiogenesis in the pathogenesis of inflammatory bowel disease.     

Endoplasmic reticulum stress and unfolded protein response are involved in paediatric inflammatory bowel disease

BackgroundEndoplasmic reticulum stress and unfolded protein response have been recently associated with the development of inflammatory bowel diseases in adults. We aimed at assessing the involvement of these pathways also in paediatric inflammatory bowel disease by analysing the expression of the main genes involved in endoplasmic reticulum stress and correlating them with the degree of intestinal inflammation.MethodsReal-time PCR and Western blot analysis of the expression of the endoplasmic reticulum stress marker HSPA5 and of selected genes representing the three pathways of unfolded protein response (IRE-XBP1, PERK-ATF4, ATF6p90-p50) in inflamed and uninflamed biopsies from 28 inflammatory bowel disease paediatric patients and 10 controls.ResultsHSPA5, PDIA4, as well as unspliced and spliced XBP1 mRNAs were significantly increased in patients’ inflamed colonic mucosa compared to uninflamed mucosa and controls. HSPA5, PDIA4, ATF6, and phospho-IRE proteins were also upregulated, indicating the activation of the IRE-XBP1 and ATF6p90-p50 branches of unfolded protein response. A positive significant correlation between interleukin-8 levels, as a marker of inflammation, and upregulated genes was found in the inflamed colonic mucosa.ConclusionA deregulation of the genes involved in the endoplasmic reticulum stress and unfolded protein response pathways may be a key component of the inflammatory response in paediatric patients with inflammatory bowel disease.