Structure-based analysis of CysZ-mediated cellular uptake of sulfate

Sulfur, most abundantly found in the environment as sulfate (SO42-), is an essential element in metabolites required by all living cells, including amino acids, co-factors and vitamins. However, current understanding of the cellular delivery of SO42- at the molecular level is limited. CysZ has been described as a SO42- permease, but its sequence family is without known structural precedent. Based on crystallographic structure information, SO42- binding and flux experiments, we provide insight into the molecular mechanism of CysZ-mediated translocation of SO42- across membranes. CysZ structures from three different bacterial species display a hitherto unknown fold and have subunits organized with inverted transmembrane topology. CysZ from Pseudomonas denitrificans assembles as a trimer of antiparallel dimers and the CysZ structures from two other species recapitulate dimers from this assembly. Mutational studies highlight the functional relevance of conserved CysZ residues

KRAS status is associated with metabolic parameters in metastatic colorectal cancer according to primary tumour location

Background: Colorectal cancer (CRC) is characterized by complex interplay between macroenvironmental factors and tumor microenvironment, leading to variable outcomes in CRC patients. To date, there is still a need to identify macroenvironment/microenvironment factors that could define subgroup of patients that would benefit from specific anti-cancer treatment in order to improve patient selection for individualized targeted-based therapy. Aims: Aim of this study was to evaluate associations between metabolic parameters and KRAS status in metastatic CRC (mCRC) according to a new tumour site classification. Methods: Retrospective data were extracted from a total of 201 patients diagnosed with mCRC between 2012 and 2017 extracted from an established CRC database at our tertiary institute. Clinical-pathological data, including age, gender, BMI, hypertension, diabetes, pre-CRC diagnosis serum lipid levels and KRAS status were recorded. Categorical characteristics were compared using chi-squared test. Continuous characteristics were compared using Mann-Whitney U test. Log rank test was used to compare hazards for survival. In all comparisons, a two-sided P value < 0.05 was considered statistically significant. Results: Out of 201 patients, 170 patients with complete serum lipid profile were included in the analysis. In recto-sigmoid cancers there was a statistically significant association between high cholesterol:high-density lipoprotein (chol:HDL) ratio and KRAS mutation (OR 2.69, 95% CI 1.1-6.4, p=0,02). In non recto-sigmoid cancers, high cholesterol was associated with KRAS WT (OR 0.39, CI 0.15-0.97, p=0.04). In 22 patients with KRAS mutated recto-sigmoid cancer stage IV at diagnosis normal chol:HDL ratio was associated with a trend to better survival (p=0.06). Conclusions: High chol:HDL ratio was significantly associated with KRAS mutated metastatic recto-sigmoid cancers. A subgoup of mCRC patients with KRAS mutated recto-sigmoid cancer may benefit from optimal lipid lowering treatment

The versatile role of gliadin peptides in celiac disease

The link between the gluten component of wheat and celiac disease (CD) was discovered in 1952 by a team of physicians from Birmingham, England. Villous atrophy was described by John W. Paulley in 1954. During the 1960s, other features of CD were elucidated; its hereditary nature was recognized in 1965, and in 1966, dermatitis herpetiformis was linked to gluten sensitivity. Following the discovery of a link between gluten and CD, it was demonstrated that gliadin, one of the two principal protein groups comprising gluten, plays a critical role in CD. It has since become clear that the different and crucial roles of gliadin in CD result from its ability to activate multiple signaling pathways that modulate CD pathology. Most of these pathways involve the host innate and adaptive immune responses, but some pathways are activated when gliadin interacts with the intestinal cellular compartment. This review covers the current knowledge of the role of gliadin peptides in CD disorders that are characterized by intraepithelial T-cells infiltration (IEL), production of autoantibodies, endosomal trafficking, alteration of intestinal barrier function and intestinal cell proliferation. In addition, it examines the ability of these characteristics to determine the main clinicopathological features of gluten sensitivity for the purpose of identifying new strategies, other than maintaining a gluten-free diet, to improve the management of CD patients in the future. (C) 2012 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved

Improving detection of celiac disease patients: a prospective study in iron-deficient blood donors without anemia in north Italy

Objective To evaluate the prevalence of celiac disease in asymptomatic iron-deficient blood donors without anemia. Material and methods Between the period February 2004 and January 2006, iron-deficient male donors with serum ferritin less than 30 ng/ml and female donors with serum ferritin less than 10 ng/ml were screened for immunoglobulin A (IgA) and IgG antitissue transglutaminase antibodies and donors with positive antibody titers were referred for endoscopy with multiple biopsies of the second/third part of duodenum. The frequency of celiac disease in iron-deficient blood donors without anemia and the predictive value of ferritin levels were analyzed. Results Of the 1679 blood donors, 579 (34.4%) were identified as iron deficient and screened for celiac disease. 290 (50%) were men (mean age: 39 years; range: 19-65) and 289 (50%) were women (mean age: 37 years; range: 19-63). Thirteen donors (2.2%) were positive for serum IgA antitissue transglutaminase antibodies, of whom six were men (2.0%) and seven were women (2.4%). 10 donors of 13 (1.7%) at histology presented alterations in the mucosal architecture according to the modified Marsh classification (Marsh I-III). Low ferritin level was not predictive for celiac disease (median serum ferritin level in celiac donors 14.7 ng/ml and in nonceliac donors 15.8 ng/ml, Wilcoxon test: P not significant). The prevalence of celiac disease among iron-deficient blood donors without anemia was 1.7%. Conclusion The prevalence of celiac disease in our population of asymptomatic iron-deficient blood donors without anemia was 1.7%. We suggest screening for celiac disease in iron-deficient individuals without anemia to increase diagnosis of asymptomatic celiac disease. (C) 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins

Fibrotic phenotype of peritumour mesenteric adipose tissue in human colon cancer: a potential hallmark of metastatic properties

The impact of tumour associated stroma on cancer metastasis is an emerging field. However, cancer associated genes in peritumoral adipose tissue (pAT) in human colon cancer have not been explored. The aim of this study was to identify differentially expressed genes (DEGs) associated with cancer pathways in mesenteric pAT compared with adjacent adipose tissue. In total, nine patients with colon cancer pathological stage T2/T4 were employed in this study. DEGs were identified in 6 patients employing Nanostring PanCancer Pathway Panel and pathway enrichment analyses were performed. Differential expression of the 5 most up-regulated and 2 down regulated genes was validated with qRT-PCR. Results showed collagen type I alpha 1 chain (COL1A1) p = 0.007; secreted frizzled related protein (SFRP2) p = 0.057; fibroblast growth factor 7 (FGF7) not significant (ns); phospholipase A2, group IIA (PLA2G2A) ns; nerve growth factor receptor (NGFR) ns; lymphoid enhancer binding factor 1 (LEF1) p = 0.03; cadherin 1, Type 1, E-cadherin (epithelial) (CDH1) 0.09. Results have highlighted down-regulation of the Wingless/Integrated (Wnt) pathway in mesenteric pAT compared to distal adipose tissue. Highly upregulated genes in mesenteric pAT were involved in extracellular matrix (ECM)-receptor interactions and focal adhesion. Highly down regulated genes were involved in the cell cycle. Immunohistochemistry revealed differential distribution of COL1A1 showing maximum levels in tumour tissue and gradually decreasing in distant adipose tissue. COL1A1 and down regulation of Wnt pathway may have a role in local invasion and distant metastasis. COL1A1 may represent a stromal prognostic biomarker and therapeutic target in colon cancer

Screening of important metabolites and KRAS

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) is an imaging-based analytical technique that can characterize the surfaces of biomaterials. We used TOF-SIMS to identify important metabolites and oncogenic KRAS mutation expressed in human colorectal cancer (CRC). We obtained 540 TOF-SIMS spectra from 180 tissue samples by scanning cryo-sections and selected discriminatory molecules using the support vector machine (SVM) algorithm. Each TOF-SIMS spectrum contained nearly 860,000 ion profiles and hundreds of spectra were analyzed; therefore, reducing the dimensionality of the original data was necessary. We performed principal component analysis after preprocessing the spectral data, and the principal components (20) of each spectrum were used as the inputs of the SVM algorithm using the R package. The performance of the algorithm was evaluated using the receiver operating characteristic (ROC) area under the curve (AUC) (0.9297). Spectral peaks (m/z) corresponding to discriminatory molecules used to classify normal and tumor samples were selected according to p-value and were assigned to arginine, α-tocopherol, and fragments of glycerophosphocholine. Pathway analysis using these discriminatory molecules showed that they were involved in gastrointestinal disease and organismal abnormalities. In addition, spectra were classified according to the expression of KRAS somatic mutation, with 0.9921 AUC. Taken together, TOF-SIMS efficiently and simultaneously screened metabolite biomarkers and performed KRAS genotyping. In addition, a machine learning algorithm was provided as a diagnostic tool applied to spectral data acquired from clinical samples prepared as frozen tissue slides, which are commonly used in a variety of biomedical tests. © 2020 The Authors. Bioengineering &amp; Translational Medicine published by Wiley Periodicals LLC on behalf of American Institute of Chemical Engineers.1

Assessment, endoscopy, and treatment in patients with acute severe ulcerative colitis during the COVID-19 pandemic (PROTECT-ASUC): a multicentre, observational, case-control study

BackgroundThere is a paucity of evidence to support safe and effective management of patients with acute severe ulcerative colitis during the COVID-19 pandemic. We sought to identify alterations to established conventional evidence-based management of acute severe ulcerative colitis during the early COVID-19 pandemic, the effect on outcomes, and any associations with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and severe COVID-19 outcomes. MethodsThe PROTECT-ASUC study was a multicentre, observational, case-control study in 60 acute secondary care hospitals throughout the UK. We included adults (≥18 years) with either ulcerative colitis or inflammatory bowel disease unclassified, who presented with acute severe ulcerative colitis and fulfilled the Truelove and Witts criteria. Cases and controls were identified as either admitted or managed in emergency ambulatory care settings between March 1, 2020, and June 30, 2020 (COVID-19 pandemic period cohort), or between Jan 1, 2019, and June 30, 2019 (historical control cohort), respectively. The primary outcome was the proportion of patients with acute severe ulcerative colitis receiving rescue therapy (including primary induction) or colectomy. The study is registered with ClinicalTrials.gov, NCT04411784. FindingsWe included 782 patients (398 in the pandemic period cohort and 384 in the historical control cohort) who met the Truelove and Witts criteria for acute severe ulcerative colitis. The proportion of patients receiving rescue therapy (including primary induction) or surgery was higher during the pandemic period than in the historical period (217 [55%] of 393 patients vs 159 [42%] of 380 patients; p=0·00024) and the time to rescue therapy was shorter in the pandemic cohort than in the historical cohort (p=0·0026). This difference was driven by a greater use of rescue and primary induction therapies with biologicals, ciclosporin, or tofacitinib in the COVID-19 pandemic period cohort than in the historical control period cohort (177 [46%] of 387 patients in the COVID-19 cohort vs 134 [36%] of 373 patients in the historical cohort; p=0·0064). During the pandemic, more patients received ambulatory (outpatient) intravenous steroids (51 [13%] of 385 patients vs 19 [5%] of 360 patients; p=0·00023). Fewer patients received thiopurines (29 [7%] of 398 patients vs 46 [12%] of 384; p=0·029) and 5-aminosalicylic acids (67 [17%] of 398 patients vs 98 [26%] of 384; p=0·0037) during the pandemic than in the historical control period. Colectomy rates were similar between the pandemic and historical control groups (64 [16%] of 389 vs 50 [13%] of 375; p=0·26); however, laparoscopic surgery was less frequently performed during the pandemic period (34 [53%] of 64] vs 38 [76%] of 50; p=0·018). Five (2%) of 253 patients tested positive for SARS-CoV-2 during hospital treatment. Two (2%) of 103 patients re-tested for SARS-CoV-2 during the 3-month follow-up were positive 5 days and 12 days, respectively, after discharge from index admission. Both recovered without serious outcomes. InterpretationThe COVID-19 pandemic altered practice patterns of gastroenterologists and colorectal surgeons in the management of acute severe ulcerative colitis but was associated with similar outcomes to a historical cohort. Despite continued use of high-dose corticosteroids and biologicals, the incidence of COVID-19 within 3 months was low and not associated with adverse COVID-19 outcomes