N. Slavova

Expression of catalytic proteasome subunits in the gut of patients with Crohn's disease

Background and purposeActivation of the transcription factor NF-κB by proteasomes and subsequent nuclear translocation of cytoplasmatic complexes play a crucial role in the intestinal inflammation. Proteasomes have a pivotal function in NF-κB activation by mediating degradation of inhibitory IκB proteins and processing of NF-κB precursor proteins. This study aims to analyze the expression of the human proteasome subunits in colonic tissue of patients with Crohn’s disease.Materials and methodsThirteen patients with Crohn’s disease and 12 control patients were studied. The expression of immunoproteasomes and constitutive proteasomes was examined by Western blot analysis, immunoflourescence and quantitative real-time PCR. For real-time PCR, AK2C was used as housekeeping gene.ResultsThe results indicate the influence of the intestinal inflammation on the expression of the proteasomes in Crohn’s disease. Proteasomes from inflamed intestine of patients with Crohn’s disease showed significantly increased expression of immunosubunits on both protein and mRNA levels. Especially, the replacement of the constitutive proteasome subunit β1 by inducible immunosubunit β1i was observed in patients with active Crohn’s disease. In contrast, relatively low abundance of immunoproteasomes was found in control tissue.ConclusionsOur data demonstrate that in contrast to normal colonic tissue, the expression of immunoproteasomes was evidently increased in the inflamed colonic mucosa of patients with Crohn’s disease. Thus, the chronic intestinal inflammation process in Crohn’s disease leads to significant alterations of proteasome subsets.

Predictors of permanent ileostomy after restorative proctocolectomy

Proctocolectomy with ileal pouch–anal anastomosis (IPAA) is a surgical approach for ulcerative colitis and familial adenomatous polyposis. This study evaluated predictors of the need for a permanent ileostomy to identify patients at high risk of IPAA failure.

Differential protein expression and oncogenic gene network link tyrosine kinase ephrin B4 receptor to aggressive gastric and gastroesophageal junction cancers

Transmembrane tyrosine‐kinase Ephrin receptors promote tumor progression and/or metastasis of several malignancies including leukemia, follicular lymphoma, glioma, malignant pleural mesothelioma, papillary thyroid carcinoma, sarcomas and ovarian, breast, bladder and non‐small cell lung cancers. They also drive intestinal stem cell proliferation and positioning, control intestinal tissue boundaries and are involved in liver, pancreatic and colorectal cancers, indicating involvement in additional digestive system malignancies. We investigated the role of Ephrin‐B4 receptor (EPHB4), and its ligand EFNB2, in gastric and gastroesophageal junction cancers in patient cohorts through computational, mathematical, molecular and immunohistochemical analyses. We show that EPHB4 is upregulated in preneoplastic gastroesophageal lesions and its expression further increased in gastroesophageal cancers in several independent cohorts. The closely related EPHB6 receptor, which also binds EFNB2, was downregulated in all tested cohorts, consistent with its tumor‐suppressive properties in other cancers. EFNB2 expression is induced in esophageal cells by acidity, suggesting that gastroesophageal reflux disease (GERD) may constitute an early triggering event in activating EFNB2–EPHB4 signaling. Association of EPHB4 to both Barretts esophagus and to advanced tumor stages, and its overexpression at the tumor invasion front and vascular endothelial cells intimate the notion that EPHB4 may be associated with multiple steps of gastroesophageal tumorigenesis. Analysis of oncogenomic signatures uncovered the first EPHB4‐associated gene network (false discovery rate: 7 × 10−90) composed of a five‐transcription factor interconnected gene network that drives proliferation, angiogenesis and invasiveness. The EPHB4 oncogenomic network provides a molecular basis for its role in tumor progression and points to EPHB4 as a potential tumor aggressiveness biomarker and drug target in gastroesophageal cancers.

NALP expression in Paneth cells provides a novel track in IBD signaling.

PurposePaneth cells are part of the innate mucosal immunity of the gut with possible regulatory function. This study intends to identify the gene expression pattern of the orthotopic and metaplastic Paneth cells, searching for differences between metaplastic occurrence between Crohns disease and ulcerative colitis.MethodsPaneth cells were collected in RNAse-free conditions via micro dissection. RNA isolation and super amplification was followed by microarray analysis of whole genome expression activity of the orthotopic and metaplastic Paneth cells. Immunohistology of β-catenin and Frizzled-5 receptor was performed.ResultsHistological analysis showed no morphological or secretory change (Frizzled-5 receptor and β-catenin) in orthotopic and metaplastic Paneth cells. Microarray analysis indicated an increased, but not mutant activation of Wnt/β-catenin signaling and firstly showed expression of NALP 1, 7, 8 and 11 in metaplastic Paneth cells.ConclusionsPaneth cells might play a NALP-mediated role in the pathogenesis of IBD.

[Proctocolectomy in ulcerative colitis : is a multistep procedure in cases of immunosuppression advisable?].

BACKGROUND The coloproctomucosectomy (CPM) is the procedure of the choice for the surgical treatment of ulcerative colitis (UC). In cases with pronounced immunosuppression (IS), a 3-step (3S) procedure [i.e., subtotal colectomy and ileal pouch-anal anastomosis (IPAA) and finally ileostomy reconstruction] is often selected. Fewer perioperative complications can be expected compared to the 2-step (2S) procedure; however, an additional in-hospital stay and surgical intervention are necessary. The aim of the present study was to compare both approaches using the clinical outcome of our patients undergoing IPAA to determine efficacy of these two concepts. PATIENTS AND METHODS From 1997-2010, a total of 225 patients were operated using a 2S or 3S IPAA procedure. Clinical outcomes were evaluated based on the number of surgical steps for the ileoanal pouch procedure and IPAA. The survey was performed within the scope of prospective study. RESULTS Of the 225 patients with CPM, 66 were excluded due to a diagnosis other than UC (familial adenomatous polyposis, indeterminate colitis, Crohns disease) and patients with permanent ILS procedures without the possibility or wish for an IPAA (n =  54). Included were 71 patients with 2S (w = 30, m = 41) and 34 patients with 3S procedures (w = 21, m = 13). Compared to the 2S procedure, the 3S procedure was shown to have shorter operation times (246 versus 296 min; p  = 0.05), shorter hospital stays (15.5 versus 24.6 days; p = 0.05), shorter intensive care unit stays (3.3 versus 7.2 days; p = 0.05), and fewer major complications (5.9 % versus 22.5 %; p = 0.035). Patients with 3S procedures had a higher BMI (26.2 versus 23.1 kg/m²; p = 0.05) and fewer required IS (10 % vs. 62 %; p < 0.05). CONCLUSION The decision for a 3S procedure in UC and pronounced IS is advisable and justified. Using a 3S procedure, immunosuppression and its influence on perioperative morbidity are thus reduced. The IPAA can be performed with shorter operation times, shorter hospital stays and fewer major complications.

Die Proktokolektomie bei Colitis ulcerosa

BACKGROUND The coloproctomucosectomy (CPM) is the procedure of the choice for the surgical treatment of ulcerative colitis (UC). In cases with pronounced immunosuppression (IS), a 3-step (3S) procedure [i.e., subtotal colectomy and ileal pouch-anal anastomosis (IPAA) and finally ileostomy reconstruction] is often selected. Fewer perioperative complications can be expected compared to the 2-step (2S) procedure; however, an additional in-hospital stay and surgical intervention are necessary. The aim of the present study was to compare both approaches using the clinical outcome of our patients undergoing IPAA to determine efficacy of these two concepts. PATIENTS AND METHODS From 1997-2010, a total of 225 patients were operated using a 2S or 3S IPAA procedure. Clinical outcomes were evaluated based on the number of surgical steps for the ileoanal pouch procedure and IPAA. The survey was performed within the scope of prospective study. RESULTS Of the 225 patients with CPM, 66 were excluded due to a diagnosis other than UC (familial adenomatous polyposis, indeterminate colitis, Crohns disease) and patients with permanent ILS procedures without the possibility or wish for an IPAA (n =  54). Included were 71 patients with 2S (w = 30, m = 41) and 34 patients with 3S procedures (w = 21, m = 13). Compared to the 2S procedure, the 3S procedure was shown to have shorter operation times (246 versus 296 min; p  = 0.05), shorter hospital stays (15.5 versus 24.6 days; p = 0.05), shorter intensive care unit stays (3.3 versus 7.2 days; p = 0.05), and fewer major complications (5.9 % versus 22.5 %; p = 0.035). Patients with 3S procedures had a higher BMI (26.2 versus 23.1 kg/m²; p = 0.05) and fewer required IS (10 % vs. 62 %; p < 0.05). CONCLUSION The decision for a 3S procedure in UC and pronounced IS is advisable and justified. Using a 3S procedure, immunosuppression and its influence on perioperative morbidity are thus reduced. The IPAA can be performed with shorter operation times, shorter hospital stays and fewer major complications.

Die Proktokolektomie bei Colitis ulcerosaProctocolectomy in ulcerative colitis

BACKGROUND The coloproctomucosectomy (CPM) is the procedure of the choice for the surgical treatment of ulcerative colitis (UC). In cases with pronounced immunosuppression (IS), a 3-step (3S) procedure [i.e., subtotal colectomy and ileal pouch-anal anastomosis (IPAA) and finally ileostomy reconstruction] is often selected. Fewer perioperative complications can be expected compared to the 2-step (2S) procedure; however, an additional in-hospital stay and surgical intervention are necessary. The aim of the present study was to compare both approaches using the clinical outcome of our patients undergoing IPAA to determine efficacy of these two concepts. PATIENTS AND METHODS From 1997-2010, a total of 225 patients were operated using a 2S or 3S IPAA procedure. Clinical outcomes were evaluated based on the number of surgical steps for the ileoanal pouch procedure and IPAA. The survey was performed within the scope of prospective study. RESULTS Of the 225 patients with CPM, 66 were excluded due to a diagnosis other than UC (familial adenomatous polyposis, indeterminate colitis, Crohns disease) and patients with permanent ILS procedures without the possibility or wish for an IPAA (n =  54). Included were 71 patients with 2S (w = 30, m = 41) and 34 patients with 3S procedures (w = 21, m = 13). Compared to the 2S procedure, the 3S procedure was shown to have shorter operation times (246 versus 296 min; p  = 0.05), shorter hospital stays (15.5 versus 24.6 days; p = 0.05), shorter intensive care unit stays (3.3 versus 7.2 days; p = 0.05), and fewer major complications (5.9 % versus 22.5 %; p = 0.035). Patients with 3S procedures had a higher BMI (26.2 versus 23.1 kg/m²; p = 0.05) and fewer required IS (10 % vs. 62 %; p < 0.05). CONCLUSION The decision for a 3S procedure in UC and pronounced IS is advisable and justified. Using a 3S procedure, immunosuppression and its influence on perioperative morbidity are thus reduced. The IPAA can be performed with shorter operation times, shorter hospital stays and fewer major complications.

Die Proktokolektomie bei Colitis ulcerosa@@@Proctocolectomy in ulcerative colitis: Ist ein mehrzeitiges Vorgehen bei Immunsuppression sinnvoll?@@@Is a multistep procedure in cases of immunosuppression advisable?

BACKGROUND The coloproctomucosectomy (CPM) is the procedure of the choice for the surgical treatment of ulcerative colitis (UC). In cases with pronounced immunosuppression (IS), a 3-step (3S) procedure [i.e., subtotal colectomy and ileal pouch-anal anastomosis (IPAA) and finally ileostomy reconstruction] is often selected. Fewer perioperative complications can be expected compared to the 2-step (2S) procedure; however, an additional in-hospital stay and surgical intervention are necessary. The aim of the present study was to compare both approaches using the clinical outcome of our patients undergoing IPAA to determine efficacy of these two concepts. PATIENTS AND METHODS From 1997-2010, a total of 225 patients were operated using a 2S or 3S IPAA procedure. Clinical outcomes were evaluated based on the number of surgical steps for the ileoanal pouch procedure and IPAA. The survey was performed within the scope of prospective study. RESULTS Of the 225 patients with CPM, 66 were excluded due to a diagnosis other than UC (familial adenomatous polyposis, indeterminate colitis, Crohns disease) and patients with permanent ILS procedures without the possibility or wish for an IPAA (n =  54). Included were 71 patients with 2S (w = 30, m = 41) and 34 patients with 3S procedures (w = 21, m = 13). Compared to the 2S procedure, the 3S procedure was shown to have shorter operation times (246 versus 296 min; p  = 0.05), shorter hospital stays (15.5 versus 24.6 days; p = 0.05), shorter intensive care unit stays (3.3 versus 7.2 days; p = 0.05), and fewer major complications (5.9 % versus 22.5 %; p = 0.035). Patients with 3S procedures had a higher BMI (26.2 versus 23.1 kg/m²; p = 0.05) and fewer required IS (10 % vs. 62 %; p < 0.05). CONCLUSION The decision for a 3S procedure in UC and pronounced IS is advisable and justified. Using a 3S procedure, immunosuppression and its influence on perioperative morbidity are thus reduced. The IPAA can be performed with shorter operation times, shorter hospital stays and fewer major complications.

Metaplastische Paneth Zellen bei chronisch-entzündlichen Darmerkrankungen

The pathogenesis of the inflammatory bowel disease comes out to be complex and multifactor event. Pathological changes seem to occur already in gene pool. The existent term of IBD genetics suggest several known susceptibility genes like NOD2, IL23R, PTPN2 for Crohn’s disease (CD), or IBD5 and ARG16L1 for ibd. Recent studies suggest reduced TCF4 expression in paediatric patients with CD [1]. The mucosal wall plays a pivotal role as high immune-competent barrier. Its function depends on the integrity of the epithelia, tide junctions, submucosal macrophages and dendritic cells. Particular interest merits the Paneth cells, as they are able to produce specific constitutive α-5 and α-6 defensins with antimicrobial activity. Next to the secretor function Paneth cells might participate in the regulation mucosal immunity, these functions are poor understood. The β-catenin/TFC signalling way regulates the epithelial cell differentiation in the crypt-villus-axis. The position and orientation of the Paneth cells depends on availability of the WNT-receptor-frizzled-5. In IBD Paneth cells occur in atypical gut segments of colon and show increased count in ileum in Crohn’s disease. The multiprotein complexes NALP are involved in activating MHC and seem to be novel track in the studies of IBD immunity disorder. NALP1 is promoting through caspase-1 activation the building of proinflammatory cytokine IL-1β, well known to be increased in Crohn’s disease and is usually expressed next to NALP3 and NOD2 in antigen presenting cells. NALP 8 is believed to have antiviral activity in reproductive cells, though no further details are known about NAPL’s 7, 8 or 11 [2].

Enhanced activity of immunoproteasomes in patiens with Crohn’s disease

The eukaryotic 20S proteasome is the main protease in the cytoplasm and nucleus composed of seven different α and seven different β subunits which form four rings stacked on top of each other. It is now known that the constitutive proteasome is the predominant form in most tissue. Our current study demonstrates that the second form, inducible immunoproteasome is more abundant in inflamed ileum and colon of Crohn’s disease. Especially, immunosubunit β1 i is increasingly expressed in the inflamed intestinal tissue of patients with Crohn’s disease. We show here that this subunit exchange alters the cleavage pattern of proteasomes in the inflamed intestine of patients with Crohn’s disease contributing directly to the activation of NF-kB by increasing the processing of p105 and degradation of IkBα. Thus, the immunoproteasome is involved in the enhanced activity of NF.-kB which is one of the most important regulators of proinflammatory gene expression in intestinal inflammation.