scholarly journals Endogenous aldehyde accumulation generates genotoxicity and exhaled biomarkers in esophageal adenocarcinoma

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Stefan Antonowicz ◽  
Zsolt Bodai ◽  
Tom Wiggins ◽  
Sheraz R. Markar ◽  
Piers R. Boshier ◽  
...  
Keyword(s):  
Early Diagnosis ◽  
Esophageal Adenocarcinoma ◽  
Clinical Features ◽  
Dna Adducts ◽  
Short Chain ◽  
Adjacent Tissue ◽  
Medium Chain ◽  
Volatile Aldehydes ◽  
Aldehyde Groups

AbstractVolatile aldehydes are enriched in esophageal adenocarcinoma (EAC) patients’ breath and could improve early diagnosis, however the mechanisms of their production are unknown. Here, we show that weak aldehyde detoxification characterizes EAC, which is sufficient to cause endogenous aldehyde accumulation in vitro. Two aldehyde groups are significantly enriched in EAC biopsies and adjacent tissue: (i) short-chain alkanals, and (ii) medium-chain alkanals, including decanal. The short-chain alkanals form DNA-adducts, which demonstrates genotoxicity and confirms inadequate detoxification. Metformin, a putative aldehyde scavenger, reduces this toxicity. Tissue and breath concentrations of the medium-chain alkanal decanal are correlated, and increased decanal is linked to reduced ALDH3A2 expression, TP53 deletion, and adverse clinical features. Thus, we present a model for increased exhaled aldehydes based on endogenous accumulation from reduced detoxification, which also causes therapeutically actionable genotoxicity. These results support EAC early diagnosis trials using exhaled aldehyde analysis.

scholarly journals Characterization of Site-Specific Mutations in a Short-Chain-Length/Medium-Chain-Length Polyhydroxyalkanoate Synthase:In VivoandIn VitroStudies of Enzymatic Activity and Substrate Specificity

2013 ◽  
Vol 79 (12) ◽  
pp. 3813-3821 ◽  
Author(s):  
Jo-Ann Chuah ◽  
Satoshi Tomizawa ◽  
Miwa Yamada ◽  
Takeharu Tsuge ◽  
Yoshiharu Doi ◽  
...  
Keyword(s):  
Chain Length ◽  
Fold Increase ◽  
Short Chain ◽  
Pha Synthase ◽  
Wild Type ◽  
Short Chain Length ◽  
Medium Chain ◽  
Medium Chain Length

ABSTRACTSaturation point mutagenesis was carried out at position 479 in the polyhydroxyalkanoate (PHA) synthase fromChromobacteriumsp. strain USM2 (PhaCCs) with specificities for short-chain-length (SCL) [(R)-3-hydroxybutyrate (3HB) and (R)-3-hydroxyvalerate (3HV)] and medium-chain-length (MCL) [(R)-3-hydroxyhexanoate (3HHx)] monomers in an effort to enhance the specificity of the enzyme for 3HHx. A maximum 4-fold increase in 3HHx incorporation and a 1.6-fold increase in PHA biosynthesis, more than the wild-type synthase, was achieved using selected mutant synthases. These increases were subsequently correlated with improved synthase activity and increased preference of PhaCCsfor 3HHx monomers. We found that substitutions with uncharged residues were beneficial, as they resulted in enhanced PHA production and/or 3HHx incorporation. Further analysis led to postulations that the size and geometry of the substrate-binding pocket are determinants of PHA accumulation, 3HHx fraction, and chain length specificity.In vitroactivities for polymerization of 3HV and 3HHx monomers were consistent within vivosubstrate specificities. Ultimately, the preference shown by wild-type and mutant synthases for either SCL (C4and C5) or MCL (C6) substrates substantiates the fundamental classification of PHA synthases.

scholarly journals In vitro human cell-based TTR-TRβ CALUX assay indicates thyroid hormone transport disruption of short-chain, medium-chain, and long-chain chlorinated paraffins

2021 ◽  
Author(s):  
Jannik Sprengel ◽  
Peter A. Behnisch ◽  
Harrie Besselink ◽  
Abraham Brouwer ◽  
Walter Vetter
Keyword(s):  
Thyroid Hormone ◽  
Structural Similarity ◽  
Short Chain ◽  
Single Chain ◽  
Medium Chain ◽  
Hormone Transport ◽  
Chlorinated Paraffins ◽  
Calux Assay ◽  
Long Chain

AbstractOver the last decades, short-chain chlorinated paraffins (SCCPs), medium-chain chlorinated paraffins (MCCPs), and long-chain chlorinated paraffins (LCCPs) have become the most heavily produced monomeric organohalogen compound class of environmental concern. However, knowledge about their toxicology is still scarce, although SCCPs were shown to have effects on the thyroid hormone system. The lack of data in the case of MCCPs and LCCPs and the structural similarity with perfluoroalkyl substances (PFAS) prompted us to test CPs in the novel TTR-TR CALUX assay for their thyroid hormone transport disrupting potential. Four self-synthesized and additionally purified single chain length CP mixtures (C10-CPs, C11-CPs, C14-CPs and C16-CPs) and two each of industrial MCCP and LCCP products were tested in parallel with PFOA. All CP mixtures influenced the TTR binding of T4, giving activities of 1,300 to 17,000 µg/g PFOA equivalents and lowest observable effect concentrations (LOELs) of 0.95 to 0.029 mM/L incubate. Highest activities and lowest LOELs were observed for C16-CPs (48.3% Cl content, activity 17,000, LOEL 0.047 mM/L) and a LCCP mixture (71.7% Cl content; activity 10,000; LOEL 0.029 mM/L). A trend of higher activities and lower LOELs towards longer chains and higher chlorination degrees was implied, but could not be statistically confirmed. Irrespectively, the less well examined and current-use LCCPs showed the highest response in the TTR-TRβ CALUX assay.

Short-Chain Fatty Acids Prevent Diabetic Nephropathy In Vivo and In Vitro

Diabetes ◽  
2018 ◽  
Vol 67 (Supplement 1) ◽  
pp. 92-OR ◽  
Author(s):  
WEI HUANG ◽  
YONG XU ◽  
YOUHUA XU ◽  
LUPING ZHOU ◽  
CHENLIN GAO
Keyword(s):  
Fatty Acids ◽  
Diabetic Nephropathy ◽  
Short Chain Fatty Acids ◽  
Short Chain ◽  
Chain Fatty Acids

In-vitro bactericidal activity of a novel plant source Plumeria pudica against some human and fish pathogenic bacteria

2020 ◽  
Vol 17 ◽  
Author(s):  
Shubhaisi Das ◽  
Sunanda Burman ◽  
Goutam Chandra
Keyword(s):  
Ethyl Acetate ◽  
Bioactive Compounds ◽  
Pathogenic Bacteria ◽  
Ethyl Acetate Extract ◽  
Positive Control ◽  
Leaf Extracts ◽  
Ms Analysis ◽  
Ft Ir ◽  
Aldehyde Groups

Background: The only remedy for up surging problem of antibiotic resistance is the discovery of antibacterial agents of natural origin. Objective: The present study was aimed at finding antibacterial potential of crude and solvent extracts of mature leaves of Plumeria pudica. Methods: Antibacterial activity of three different solvent extracts were evaluated in four human and four fish pathogenic bacteria by measuring the zone of inhibition and determining Minimum Inhibitory Concentration and Minimum Bactericidal Concentration values. Standard antibiotics were used as positive control. Preliminary phytochemical screening of most effective extract i.e., ethyl acetate extract, Fourier Transform Infra Red analysis and GC-MS analysis of the Thin Layer Chromatographic (TLC) fraction of ethyl acetate extract were done meticulously. All experiments were done thrice and analyzed statistically. Results: Crude leaf extracts and solvent extracts caused good inhibition of bacterial growth in all selected bacteria. Ethyl acetate extract showed highest inhibition zones in all tested strains with maximum inhibition (19.50±0.29 mm) in Escherichia coli (MTCC 739). MBC/MIC of the extracts indicated that all three solvent extracts were bactericidal. Preliminary phytochemical tests revealed the presence of tannins, steroids and alkaloids and FT-IR analysis revealed presence of many functional groups namely alcoholic, amide, amine salt and aldehyde groups. From the GC-MS analysis of TLC fraction of ethyl acetate extract five different bioactive compounds e.g., 2,4-ditert –butylphenyl 5-hydroxypentanoate, Oxalic acid; allyl nonyl ester, 7,9-Ditert-butyl-1-oxaspiro(4,5)deca-6,9-diene-2,8-dione, Dibutyl phthalate and 2,3,5,8-tetramethyl-decane were identified. Conclusion: Leaf extracts of P. pudica contain bioactive compounds that can be used as broad spectrum bactericidal agent.

scholarly journals Identification of New Markers of Alcohol-Derived DNA Damage in Humans

Biomolecules ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 366
Author(s):  
Valeria Guidolin ◽  
Erik S. Carlson ◽  
Andrea Carrà ◽  
Peter W. Villalta ◽  
Laura A. Maertens ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dna Adducts ◽  
Neutral Loss ◽  
Alcohol Exposure ◽  
Dose Dependence ◽  
Accurate Mass ◽  
Constant Neutral Loss ◽  
Covalent Modifications ◽  
Underlying Mechanisms

Alcohol consumption is a risk factor for the development of several cancers, including those of the head and neck and the esophagus. The underlying mechanisms of alcohol-induced carcinogenesis remain unclear; however, at these sites, alcohol-derived acetaldehyde seems to play a major role. By reacting with DNA, acetaldehyde generates covalent modifications (adducts) that can lead to mutations. Previous studies have shown a dose dependence between levels of a major acetaldehyde-derived DNA adduct and alcohol exposure in oral-cell DNA. The goal of this study was to optimize a mass spectrometry (MS)-based DNA adductomic approach to screen for all acetaldehyde-derived DNA adducts to more comprehensively characterize the genotoxic effects of acetaldehyde in humans. A high-resolution/-accurate-mass data-dependent constant-neutral-loss-MS3 methodology was developed to profile acetaldehyde-DNA adducts in purified DNA. This resulted in the identification of 22 DNA adducts. In addition to the expected N2-ethyldeoxyguanosine (after NaBH3CN reduction), two previously unreported adducts showed prominent signals in the mass spectra. MSn fragmentation spectra and accurate mass were used to hypothesize the structure of the two new adducts, which were then identified as N6-ethyldeoxyadenosine and N4-ethyldeoxycytidine by comparison with synthesized standards. These adducts were quantified in DNA isolated from oral cells collected from volunteers exposed to alcohol, revealing a significant increase after the exposure. In addition, 17 of the adducts identified in vitro were detected in these samples confirming our ability to more comprehensively characterize the DNA damage deriving from alcohol exposures.

scholarly journals Nrf2/Keap1-Pathway Activation and Reduced Susceptibility to Chemotherapy Treatment by Acidification in Esophageal Adenocarcinoma Cells

Cancers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2806
Author(s):  
Lucie Storz ◽  
Philipp Walther ◽  
Olga Chemnitzer ◽  
Orestis Lyros ◽  
Stefan Niebisch ◽  
...  
Keyword(s):  
Esophageal Adenocarcinoma ◽  
Squamous Epithelium ◽  
Acid Reflux ◽  
Cellular Damage ◽  
Pathway Activation ◽  
Cellular Context ◽  
Vitro Model ◽  
Nfκb Pathway ◽  
Eac Cells

Chronic acid reflux causes cellular damage and inflammation in the lower esophagus. Due to these irritating insults, the squamous epithelium is replaced by metaplastic epithelium, which is a risk factor for the development of esophageal adenocarcinoma (EAC). In this study, we investigated the acid susceptibility in a Barrett’s cell culture in vitro model, using six cell lines, derived from squamous epithelium (EPC1 and EPC2), metaplasia (CP-A), dysplasia (CP-B), and EAC (OE33 and OE19) cells. Cells exposed to acidic pH showed a decreased viability dependent on time, pH, and progression status in the Barrett’s sequence, with the highest acid susceptibility in the squamous epithelium (EPC1 and EPC2), and the lowest in EAC cells. Acid pulsing was accompanied with an activation of the Nrf2/Keap1- and the NFκB-pathway, resulting in an increased expression of HO1—independent of the cellular context. OE33 showed a decreased responsiveness towards 5-FU, when the cells were grown in acidic conditions (pH 6 and pH 5.5). Our findings suggest a strong damage of squamous epithelium by gastroesophageal reflux, while Barrett’s dysplasia and EAC cells apparently exert acid-protective features, which lead to a cellular resistance against acid reflux.

PSIII-12 In vitro Evaluation of Purified Fiber Sources for Production of Short-chain Fatty Acids Using Pig Cecal Content as an Inoculum

2021 ◽  
Vol 99 (Supplement_1) ◽  
pp. 177-177
Author(s):  
Gabriela E Martinez Padilla ◽  
Rajesh Jha ◽  
Vivek Fellner ◽  
Eric van Heugten
Keyword(s):  
Fatty Acids ◽  
Enzymatic Hydrolysis ◽  
Resistant Starch ◽  
Potato Starch ◽  
Short Chain ◽  
Gas Liquid Chromatography ◽  
Citrus Peel ◽  
Starch Potato ◽  
Chain Fatty Acids

Abstract This study evaluated short-chain fatty acid (SCFA) production from purified fiber sources when fermented in vitro using pig cecal contents as an inoculum. Fiber sources of interest were inulin from chicory root (native and long-chain inulin with 90 and 98% fiber, respectively), pectin from citrus peel (high methoxyl pectin), resistant starch (native starch), potato starch (commercial grade), and β-glucan (β-1,3;β-1,6 yeast-derived). Cellulose and cornstarch were used as indigestible and highly digestible carbohydrates, respectively. Triplicate samples of substrates (2 g) were subjected to enzymatic hydrolysis with pepsin and pancreatin for 6 h. Subsequently, hydrolyzed residues (200 mg) were incubated under anaerobic conditions at 39°C with 30 mL solution of cecal inoculum collected from 3 sows fed a standard commercial diet and buffered mineral solution. After 48 h of incubation, solutions from fermented samples were analyzed for pH, SCFA, and branched-chain fatty acids (BCFA) using gas-liquid chromatography. Enzymatic hydrolysis had no effect on digestion of β-glucan, but total SCFA concentration after fermentation was highest (26.13 mmol/g) followed by resistant starch (22.61 mmol/g) and potato starch (22.20 mmol/g) and was lowest for cellulose (13.91 mmol/g). In contrast, native inulin was highly digested during enzymatic hydrolysis, resulting in the lowest substrate available for fermentation (11.84% DM) and the highest pH (5.98). Enzymatic hydrolysis and fermentation of resistant starch increased (P< 0.001) concentrations of acetate (0.60 mg/g), whereas potato starch and β-glucan yielded more butyrate (0.60 and 0.54 mg/g respectively), and β-glucan resulted in greater (P< 0.001) propionate concentrations (0.69 mg/g). Pectin resulted in the highest fermentation (82.38% DM disappearance) and the lowest pH (4.03) compared to the other fiber sources (P< 0.001) and yielded the lowest BCFA concentration (1.89 mM, P< 0.001). Results suggest that fermentation of resistant starch, potato starch, and β-glucan produced higher SCFA concentrations, while pectin resulted in a decreased pH of fermentation solution.

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