1
|
Awtrey N, Beckstein O. Kinetic Diagram Analysis: A Python Library for Calculating Steady-State Observables of Kinetic Systems Analytically. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.27.596119. [PMID: 38854140 PMCID: PMC11160680 DOI: 10.1101/2024.05.27.596119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Kinetic diagrams are commonly used to represent biochemical systems in order to study phenomena such as free energy transduction and ion selectivity. While numerical methods are commonly used to analyze such kinetic networks, the diagram method by King, Altman and Hill makes it possible to construct exact algebraic expressions for steady-state observables in terms of the rate constants of the kinetic diagram. However, manually obtaining these expressions becomes infeasible for models of even modest complexity as the number of the required intermediate diagrams grows with the factorial of the number of states in the diagram. We developed Kinetic Diagram Analysis (KDA), a Python library that programmatically generates the relevant diagrams and expressions from a user-defined kinetic diagram. KDA outputs symbolic expressions for state probabilities and cycle fluxes at steady-state that can be symbolically manipulated and evaluated to quantify macroscopic system observables. We demonstrate the KDA approach for examples drawn from the biophysics of active secondary transmembrane transporters. For a generic 6-state antiporter model, we show how the introduction of a single leakage transition reduces transport efficiency by quantifying substrate turnover. We apply KDA to a real-world example, the 8-state free exchange model of the small multidrug resistance transporter EmrE of Hussey et al (J General Physiology 152 (2020), e201912437), where a change in transporter phenotype is achieved by biasing two different subsets of kinetic rates: alternating access and substrate unbinding rates. KDA is made available as open source software under the GNU General Public License version 3.
Collapse
Affiliation(s)
- Nikolaus Awtrey
- Arizona State University, Department of Physics, Tempe AZ, USA
| | - Oliver Beckstein
- Arizona State University, Department of Physics, Tempe AZ, USA
- Arizona State University, Center for Biological Physics, Tempe AZ, USA
| |
Collapse
|
2
|
Su-Arcaro C, Liao W, Bieniek K, Constantino MA, Decker SM, Turner BS, Bansil R. Unraveling the Intertwined Effect of pH on Helicobacter pylori Motility and the Microrheology of the Mucin-Based Medium It Swims in. Microorganisms 2023; 11:2745. [PMID: 38004756 PMCID: PMC10673263 DOI: 10.3390/microorganisms11112745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 10/16/2023] [Accepted: 11/03/2023] [Indexed: 11/26/2023] Open
Abstract
The gastric pathogen, Helicobacter pylori bacteria have to swim across a pH gradient from 2 to 7 in the mucus layer to colonize the gastric epithelium. Previous studies from our group have shown that porcine gastric mucin (PGM) gels at an acidic pH < 4, and H. pylori bacteria are unable to swim in the gel, although their flagella rotate. Changing pH impacts both the rheological properties of gastric mucin and also influences the proton (H+)-pumped flagellar motors of H. pylori as well as their anti-pH sensing receptors. To unravel these intertwined effects of acidic pH on both the viscoelastic properties of the mucin-based mucus as well as the flagellar motors and chemo-receptors of the bacterium, we compared the motility of H. pylori in PGM with that in Brucella broth (BB10) at different pH values using phase contrast microscopy to track the motion of the bacteria. The results show that the distribution of swimming speeds and other characteristics of the bacteria trajectories exhibit pH-dependent differences in both media. The swimming speed exhibits a peak at pH 4 in BB10, and a less pronounced peak at a higher pH of 5 in PGM. At all pH values, the bacteria swam faster and had a longer net displacement in BB10 compared to PGM. While the bacteria were stuck in PGM gels at pH < 4, they swam at these acidic pH values in BB10, although with reduced speed. Decreasing pH leads to a decreased fraction of motile bacteria, with a decreased contribution of the faster swimmers to the distributions of speeds and net displacement of trajectories. The body rotation rate is weakly dependent on pH in BB10, whereas in PGM bacteria that are immobilized in the low pH gel are capable of mechano-sensing and rotate faster. Bacteria can be stuck in the gel in various ways, including the flagella getting entangled in the fibers of the gel or the cell body being stuck to the gel. Our results show that in BB10, swimming is optimized at pH4, reflecting the combined effects of pH sensing by anti-pH tactic receptors and impact on H+ pumping of flagellar motors, while the increase in viscosity of PGM with decreasing pH and gelation below pH 4 lead to further reduction in swimming speed, with optimal swimming at pH 5 and immobilization of bacteria below pH 4.
Collapse
Affiliation(s)
- Clover Su-Arcaro
- Department of Physics, Boston University, Boston, MA 02215, USA; (C.S.-A.); (W.L.); (K.B.); (M.A.C.); (S.M.D.)
| | - Wentian Liao
- Department of Physics, Boston University, Boston, MA 02215, USA; (C.S.-A.); (W.L.); (K.B.); (M.A.C.); (S.M.D.)
| | - Katarzyna Bieniek
- Department of Physics, Boston University, Boston, MA 02215, USA; (C.S.-A.); (W.L.); (K.B.); (M.A.C.); (S.M.D.)
| | - Maira A. Constantino
- Department of Physics, Boston University, Boston, MA 02215, USA; (C.S.-A.); (W.L.); (K.B.); (M.A.C.); (S.M.D.)
| | - Savannah M. Decker
- Department of Physics, Boston University, Boston, MA 02215, USA; (C.S.-A.); (W.L.); (K.B.); (M.A.C.); (S.M.D.)
| | - Bradley S. Turner
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA;
| | - Rama Bansil
- Department of Physics, Boston University, Boston, MA 02215, USA; (C.S.-A.); (W.L.); (K.B.); (M.A.C.); (S.M.D.)
| |
Collapse
|
3
|
Wang CM, Fernez MT, Woolston BM, Carrier RL. Native gastrointestinal mucus: Critical features and techniques for studying interactions with drugs, drug carriers, and bacteria. Adv Drug Deliv Rev 2023; 200:114966. [PMID: 37329985 DOI: 10.1016/j.addr.2023.114966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 06/09/2023] [Accepted: 06/12/2023] [Indexed: 06/19/2023]
Abstract
Gastrointestinal mucus plays essential roles in modulating interactions between intestinal lumen contents, including orally delivered drug carriers and the gut microbiome, and underlying epithelial and immune tissues and cells. This review is focused on the properties of and methods for studying native gastrointestinal mucus and its interactions with intestinal lumen contents, including drug delivery systems, drugs, and bacteria. The properties of gastrointestinal mucus important to consider in its analysis are first presented, followed by a discussion of different experimental setups used to study gastrointestinal mucus. Applications of native intestinal mucus are then described, including experimental methods used to study mucus as a barrier to drug delivery and interactions with intestinal lumen contents that impact barrier properties. Given the significance of the microbiota in health and disease, its impact on drug delivery and drug metabolism, and the use of probiotics and microbe-based delivery systems, analysis of interactions of bacteria with native intestinal mucus is then reviewed. Specifically, bacteria adhesion to, motility within, and degradation of mucus is discussed. Literature noted is focused largely on applications of native intestinal mucus models as opposed to isolated mucins or reconstituted mucin gels.
Collapse
Affiliation(s)
- Chia-Ming Wang
- Department of Bioengineering, Northeastern University, Boston, MA, USA
| | - Matthew T Fernez
- Department of Chemical Engineering, Northeastern University, Boston, MA, USA
| | - Benjamin M Woolston
- Department of Chemical Engineering, Northeastern University, Boston, MA, USA
| | - Rebecca L Carrier
- Department of Bioengineering, Northeastern University, Boston, MA, USA; Department of Chemical Engineering, Northeastern University, Boston, MA, USA; Department of Biology, Northeastern University, Boston, MA, USA.
| |
Collapse
|
4
|
Sauvaitre T, Van Landuyt J, Durif C, Roussel C, Sivignon A, Chalancon S, Uriot O, Van Herreweghen F, Van de Wiele T, Etienne-Mesmin L, Blanquet-Diot S. Role of mucus-bacteria interactions in Enterotoxigenic Escherichia coli (ETEC) H10407 virulence and interplay with human microbiome. NPJ Biofilms Microbiomes 2022; 8:86. [PMID: 36266277 PMCID: PMC9584927 DOI: 10.1038/s41522-022-00344-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 10/04/2022] [Indexed: 11/09/2022] Open
Abstract
The intestinal mucus layer has a dual role in human health constituting a well-known microbial niche that supports gut microbiota maintenance but also acting as a physical barrier against enteric pathogens. Enterotoxigenic Escherichia coli (ETEC), the major agent responsible for traveler's diarrhea, is able to bind and degrade intestinal mucins, representing an important but understudied virulent trait of the pathogen. Using a set of complementary in vitro approaches simulating the human digestive environment, this study aimed to describe how the mucus microenvironment could shape different aspects of the human ETEC strain H10407 pathophysiology, namely its survival, adhesion, virulence gene expression, interleukin-8 induction and interactions with human fecal microbiota. Using the TNO gastrointestinal model (TIM-1) simulating the physicochemical conditions of the human upper gastrointestinal (GI) tract, we reported that mucus secretion and physical surface sustained ETEC survival, probably by helping it to face GI stresses. When integrating the host part in Caco2/HT29-MTX co-culture model, we demonstrated that mucus secreting-cells favored ETEC adhesion and virulence gene expression, but did not impede ETEC Interleukin-8 (IL-8) induction. Furthermore, we proved that mucosal surface did not favor ETEC colonization in a complex gut microbial background simulated in batch fecal experiments. However, the mucus-specific microbiota was widely modified upon the ETEC challenge suggesting its role in the pathogen infectious cycle. Using multi-targeted in vitro approaches, this study supports the major role played by mucus in ETEC pathophysiology, opening avenues in the design of new treatment strategies.
Collapse
Affiliation(s)
- Thomas Sauvaitre
- Université Clermont Auvergne, INRAE, UMR 454 MEDIS, Microbiologie Environnement Digestif et Santé (MEDIS), CRNH Auvergne, 63000, Clermont-Ferrand, France.,Ghent University, Faculty of Bioscience Engineering, Center for Microbial Ecology and Technology (CMET), Ghent, Belgium
| | - Josefien Van Landuyt
- Ghent University, Faculty of Bioscience Engineering, Center for Microbial Ecology and Technology (CMET), Ghent, Belgium
| | - Claude Durif
- Université Clermont Auvergne, INRAE, UMR 454 MEDIS, Microbiologie Environnement Digestif et Santé (MEDIS), CRNH Auvergne, 63000, Clermont-Ferrand, France
| | - Charlène Roussel
- Université Laval, Nutrition and Functional Foods Institute (INAF), 2440 Bd Hochelaga Suite 1710, Québec, QC, G1V 0A6, Canada
| | - Adeline Sivignon
- Université Clermont Auvergne, UMR 1071 Inserm, USC-INRAE 2018, Microbes, Intestin, Inflammation et Susceptibilité de l'Hôte (M2iSH), 63000, Clermont-Ferrand, France
| | - Sandrine Chalancon
- Université Clermont Auvergne, INRAE, UMR 454 MEDIS, Microbiologie Environnement Digestif et Santé (MEDIS), CRNH Auvergne, 63000, Clermont-Ferrand, France
| | - Ophélie Uriot
- Université Clermont Auvergne, INRAE, UMR 454 MEDIS, Microbiologie Environnement Digestif et Santé (MEDIS), CRNH Auvergne, 63000, Clermont-Ferrand, France
| | - Florence Van Herreweghen
- Ghent University, Faculty of Bioscience Engineering, Center for Microbial Ecology and Technology (CMET), Ghent, Belgium
| | - Tom Van de Wiele
- Ghent University, Faculty of Bioscience Engineering, Center for Microbial Ecology and Technology (CMET), Ghent, Belgium
| | - Lucie Etienne-Mesmin
- Université Clermont Auvergne, INRAE, UMR 454 MEDIS, Microbiologie Environnement Digestif et Santé (MEDIS), CRNH Auvergne, 63000, Clermont-Ferrand, France
| | - Stéphanie Blanquet-Diot
- Université Clermont Auvergne, INRAE, UMR 454 MEDIS, Microbiologie Environnement Digestif et Santé (MEDIS), CRNH Auvergne, 63000, Clermont-Ferrand, France.
| |
Collapse
|
5
|
Dubbelboer IR, Barmpatsalou V, Rodler A, Karlsson E, Filipe Nunes S, Holmberg J, Häggström J, A. S. Bergström C. Gastrointestinal mucus in dog: physiological characteristics, composition, and structural properties. Eur J Pharm Biopharm 2022; 173:92-102. [DOI: 10.1016/j.ejpb.2022.02.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 11/17/2021] [Accepted: 02/23/2022] [Indexed: 11/27/2022]
|
6
|
Parrish A, Boudaud M, Kuehn A, Ollert M, Desai MS. Intestinal mucus barrier: a missing piece of the puzzle in food allergy. Trends Mol Med 2021; 28:36-50. [PMID: 34810087 DOI: 10.1016/j.molmed.2021.10.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 10/22/2021] [Accepted: 10/22/2021] [Indexed: 12/13/2022]
Abstract
The prevalence of food allergies has reached epidemic levels but the cause remains largely unknown. We discuss the clinical relevance of the gut mucosal barrier as a site for allergic sensitization to food. In this context, we focus on an important but overlooked part of the mucosal barrier in pathogenesis, the glycoprotein-rich mucus layer, and call attention to both beneficial and detrimental aspects of mucus-gut microbiome interactions. Studying the intricate links between the mucus barrier, the associated bacteria, and the mucosal immune system may advance our understanding of the mechanisms and inform prevention and treatment strategies in food allergy.
Collapse
Affiliation(s)
- Amy Parrish
- Department of Infection and Immunity, Luxembourg Institute of Health, 4354 Esch-sur-Alzette, Luxembourg; Faculty of Science, Technology and Medicine, University of Luxembourg, 4365 Esch-sur-Alzette, Luxembourg
| | - Marie Boudaud
- Department of Infection and Immunity, Luxembourg Institute of Health, 4354 Esch-sur-Alzette, Luxembourg
| | - Annette Kuehn
- Department of Infection and Immunity, Luxembourg Institute of Health, 4354 Esch-sur-Alzette, Luxembourg
| | - Markus Ollert
- Department of Infection and Immunity, Luxembourg Institute of Health, 4354 Esch-sur-Alzette, Luxembourg; Odense Research Center for Anaphylaxis, Department of Dermatology and Allergy Center, Odense University Hospital, University of Southern Denmark, 5000 Odense, Denmark
| | - Mahesh S Desai
- Department of Infection and Immunity, Luxembourg Institute of Health, 4354 Esch-sur-Alzette, Luxembourg; Odense Research Center for Anaphylaxis, Department of Dermatology and Allergy Center, Odense University Hospital, University of Southern Denmark, 5000 Odense, Denmark.
| |
Collapse
|
7
|
Aggarwal M, Cogan NG, Lewis OL. Physiological insights into electrodiffusive maintenance of gastric mucus through sensitivity analysis and simulations. J Math Biol 2021; 83:30. [PMID: 34436680 PMCID: PMC8459737 DOI: 10.1007/s00285-021-01643-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 06/24/2021] [Accepted: 07/18/2021] [Indexed: 11/28/2022]
Abstract
It is generally accepted that the gastric mucosa and adjacent mucus layer are critical in the maintenance of a pH gradient from stomach lumen to stomach wall, protecting the mucosa from the acidic environment of the lumen and preventing auto-digestion of the epithelial layer. No conclusive study has shown precisely which physical, chemical, and regulatory mechanisms are responsible for maintaining this gradient. However, experimental work and modeling efforts have suggested that concentration dependent ion-exchange at the epithelial wall, together with hydrogen ion/mucus network binding, may produce the enormous pH gradients seen in vivo. As of yet, there has been no exhaustive study of how sensitive these modeling results are with respect to variation in model parameters, nor how sensitive such a regulatory mechanism may be to variation in physical/biological parameters. In this work, we perform sensitivity analysis (using Sobol' Indices) on a previously reported model of gastric pH gradient maintenance. We quantify the sensitivity of mucosal wall pH (as a proxy for epithelial health) to variations in biologically relevant parameters and illustrate how variations in these parameters affects the distribution of the measured pH values. In all parameter regimes, we see that the rate of cation/hydrogen exchange at the epithelial wall is the dominant parameter/effect with regards to variation in mucosal pH. By careful sensitivity analysis, we also investigate two different regimes representing high and low hydrogen secretion with different physiological interpretations. By complementing mechanistic modeling and biological hypotheses testing with parametric sensitivity analysis we are able to conclude which biological processes must be tightly regulated in order to robustly maintain the pH values necessary for healthy function of the stomach.
Collapse
Affiliation(s)
| | - N G Cogan
- Florida State University, Tallahassee, USA
| | | |
Collapse
|
8
|
Mussel M, Basser PJ, Horkay F. Ion-Induced Volume Transition in Gels and Its Role in Biology. Gels 2021; 7:20. [PMID: 33670826 PMCID: PMC8005988 DOI: 10.3390/gels7010020] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 02/09/2021] [Accepted: 02/11/2021] [Indexed: 12/12/2022] Open
Abstract
Incremental changes in ionic composition, solvent quality, and temperature can lead to reversible and abrupt structural changes in many synthetic and biopolymer systems. In the biological milieu, this nonlinear response is believed to play an important functional role in various biological systems, including DNA condensation, cell secretion, water flow in xylem of plants, cell resting potential, and formation of membraneless organelles. While these systems are markedly different from one another, a physicochemical framework that treats them as polyelectrolytes, provides a means to interpret experimental results and make in silico predictions. This article summarizes experimental results made on ion-induced volume phase transition in a polyelectrolyte model gel (sodium polyacrylate) and observations on the above-mentioned biological systems indicating the existence of a steep response.
Collapse
Affiliation(s)
- Matan Mussel
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA;
| | | | - Ferenc Horkay
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA;
| |
Collapse
|
9
|
Esteban-Fernández de Ávila B, Lopez-Ramirez MA, Mundaca-Uribe R, Wei X, Ramírez-Herrera DE, Karshalev E, Nguyen B, Fang RH, Zhang L, Wang J. Multicompartment Tubular Micromotors Toward Enhanced Localized Active Delivery. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e2000091. [PMID: 32419239 DOI: 10.1002/adma.202000091] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2020] [Revised: 03/28/2020] [Accepted: 04/18/2020] [Indexed: 05/20/2023]
Abstract
A tubular micromotor with spatially resolved compartments is presented toward efficient site-specific cargo delivery, with a back-end zinc (Zn) propellant engine segment and an upfront cargo-loaded gelatin segment further protected by a pH-responsive cap. The multicompartment micromotors display strong gastric-powered propulsion with tunable lifetime depending on the Zn segment length. Such propulsion significantly enhances the motor distribution and retention in the gastric tissues, by pushing and impinging the front-end cargo segment onto the stomach wall. Once the micromotor penetrates the gastric mucosa (pH ≥ 6.0), its pH-responsive cap dissolves, promoting the autonomous localized cargo release. The fabrication process, physicochemical properties, and propulsion behavior are systematically tested and discussed. Using a mouse model, the multicompartment motors, loaded with a model cargo, demonstrate a homogeneous cargo distribution along with approximately four-fold enhanced retention in the gastric lining compared to monocompartment motors, while showing no apparent toxicity. Therapeutic payloads can also be loaded into the pH-responsive cap, in addition to the gelatin-based compartment, leading to concurrent delivery and sequential release of dual cargos toward combinatorial therapy. Overall, this multicompartment micromotor system provides unique features and advantages that will further advance the development of synthetic micromotors for active transport and localized delivery of biomedical cargos.
Collapse
Affiliation(s)
| | | | - Rodolfo Mundaca-Uribe
- Department of Nanoengineering, University of California San Diego, La Jolla, CA, 92093, USA
| | - Xiaoli Wei
- Department of Nanoengineering, University of California San Diego, La Jolla, CA, 92093, USA
| | | | - Emil Karshalev
- Department of Nanoengineering, University of California San Diego, La Jolla, CA, 92093, USA
| | - Bryan Nguyen
- Department of Nanoengineering, University of California San Diego, La Jolla, CA, 92093, USA
| | - Ronnie H Fang
- Department of Nanoengineering, University of California San Diego, La Jolla, CA, 92093, USA
| | - Liangfang Zhang
- Department of Nanoengineering, University of California San Diego, La Jolla, CA, 92093, USA
| | - Joseph Wang
- Department of Nanoengineering, University of California San Diego, La Jolla, CA, 92093, USA
| |
Collapse
|
10
|
van der Sman RGM, Houlder S, Cornet S, Janssen A. Physical chemistry of gastric digestion of proteins gels. Curr Res Food Sci 2020; 2:45-60. [PMID: 32914111 PMCID: PMC7473360 DOI: 10.1016/j.crfs.2019.11.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
In this paper, we present the rich physics and chemistry of the gastric digestion of protein gels. Knowledge of this matter is important for the development of sustainable protein foods that are based on novel proteins sources like plant proteins or insects. Their digestibility is an important question in the design of these new protein foods. As polyelectrolyte gels, they can undergo volume changes upon shifts in pH or ionic strengths, as protein gels experience when entering the gastric environment. We show that these volume changes can be modelled using the Flory-Rehner theory, combined with Gibbs-Donnan theory accounting for the distribution of electrolytes over gel and bath. In-vitro experiments of soy protein gels in simulated gastric fluid indeed show intricate swelling behaviour, at first the gels show swelling but at longer times they shrink again. Simulations performed with the Flory-Rehner/Gibbs-Donnan theory reproduce qualitatively similar behaviour. In the final part of the paper, we discuss how the model must be extended to model realistic conditions existing in the in-vivo gastric environment.
Collapse
Affiliation(s)
- R G M van der Sman
- Wageningen Food Biobased Research, Wageningen University & Research, the Netherlands
- Food Process Engineering, Wageningen University & Research, the Netherlands
| | - Sian Houlder
- Food Process Engineering, Wageningen University & Research, the Netherlands
| | - Steven Cornet
- Wageningen Food Biobased Research, Wageningen University & Research, the Netherlands
- Food Process Engineering, Wageningen University & Research, the Netherlands
| | - Anja Janssen
- Food Process Engineering, Wageningen University & Research, the Netherlands
| |
Collapse
|
11
|
Jiang ZX, Nong B, Liang LX, Yan YD, Zhang G. Differential diagnosis of Helicobacter pylori-associated gastritis with the linked-color imaging score. Dig Liver Dis 2019; 51:1665-1670. [PMID: 31420229 DOI: 10.1016/j.dld.2019.06.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2018] [Revised: 06/23/2019] [Accepted: 06/30/2019] [Indexed: 12/11/2022]
Abstract
BACKGROUND Helicobacter pylori (H. pylori) infection in gastric mucosa is the main risk factor for gastric cancer. The purpose of this study was to assess the value of the linked-color imaging (LCI) score for the identification of H. pylori-associated gastritis. METHODS A total of 358 patients were enrolled in the study. H. pylori was positive in 127 cases and negative in 231 cases. Redness of fundus glands, granular erosion, purple mucus (+) and mucus lake turbidity were investigated by the LCI mode of endoscopy. Logistic regression was used to screen the observation indexes and their relative partial regression coefficients, which were helpful for the differential diagnosis of H. pylori infection. Then, each observation index was scored according to the partial regression coefficient. RESULTS Using a total scores of 3.5 as the cut-off value, the sensitivity and specificity were 83.8% and 99.5%, respectively, for the differential diagnosis of H. pylori gastritis. The area under the curve was 95.3%. CONCLUSIONS The LCI score showed high sensitivity and specificity for the differential diagnosis of H. pylori-associated gastritis and is an effective method for identifying H. pylori infection in gastric mucosa.
Collapse
Affiliation(s)
- Zhang-Xiu Jiang
- Department of Digestion, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, PR China
| | - Bing Nong
- Department of Digestion, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, PR China.
| | - Lie-Xin Liang
- Department of Digestion, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, PR China
| | - Yu-Dong Yan
- Department of Digestion, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, PR China
| | - Guo Zhang
- Department of Digestion, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, PR China
| |
Collapse
|
12
|
The Interaction of Helicobacter pylori with TFF1 and Its Role in Mediating the Tropism of the Bacteria Within the Stomach. Int J Mol Sci 2019; 20:ijms20184400. [PMID: 31500233 PMCID: PMC6769565 DOI: 10.3390/ijms20184400] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 08/27/2019] [Accepted: 09/06/2019] [Indexed: 02/07/2023] Open
Abstract
Helicobacter pylori colonises the human stomach and has tropism for the gastric mucin, MUC5AC. The majority of organisms live in the adherent mucus layer within their preferred location, close to the epithelial surface where the pH is near neutral. Trefoil factor 1 (TFF1) is a small trefoil protein co-expressed with the gastric mucin MUC5AC in surface foveolar cells and co-secreted with MUC5AC into gastric mucus. Helicobacter pylori binds with greater avidity to TFF1 dimer, which is present in gastric mucus, than to TFF1 monomer. Binding of H. pylori to TFF1 is mediated by the core oligosaccharide subunit of H. pylori lipopolysaccharide at pH 5.0–6.0. Treatment of H. pylori lipopolysaccharide with mannosidase or glucosidase inhibits its interaction with TFF1. Both TFF1 and H. pylori have a propensity for binding to mucins with terminal non-reducing α- or β-linked N-acetyl-d-glucosamine or α-(2,3) linked sialic acid or Gal-3-SO42−. These findings are strong evidence that TFF1 has carbohydrate-binding properties that may involve a conserved patch of aromatic hydrophobic residues on the surface of its trefoil domain. The pH-dependent lectin properties of TFF1 may serve to locate H. pylori deep in the gastric mucus layer close to the epithelium rather than at the epithelial surface. This restricted localisation could limit the interaction of H. pylori with epithelial cells and the subsequent host signalling events that promote inflammation.
Collapse
|
13
|
Abstract
PURPOSE OF REVIEW The gastroduodenal mucosal layer is a complex and dynamic system that functions in an interdependent manner to resist injury. We review and summarize the most updated knowledge about gastroduodenal defense mechanisms and specifically address (a) the mucous barrier, (b) membrane and cellular properties, and vascular, hormonal, and (c) gaseous mediators. RECENT FINDINGS Trefoil factor family peptides play a crucial role in cellular restitution by increasing cellular permeability and expression of aquaporin channels, aiding cellular migration and tissue repair. Additionally, evidence suggests that the symptoms of functional dyspepsia may be attributed to alterations in the duodenum, including low-grade inflammation and increased mucosal permeability. The interaction of the various mucosal protective components helps maintain structural and functional homeostasis. There is increasing evidence suggesting that the upper GI microbiota plays a crucial role in the defense mechanisms. However, this warrants further investigation.
Collapse
Affiliation(s)
- Gian M Galura
- Department of Internal Medicine, Texas Tech University Health Science Center, El Paso, TX, USA
| | - Luis O Chavez
- Department of Internal Medicine, Texas Tech University Health Science Center, El Paso, TX, USA
| | - Alejandro Robles
- Department of Internal Medicine, Texas Tech University Health Science Center, El Paso, TX, USA
| | - Richard McCallum
- Department of Gastroenterology, Texas Tech University Health Science Center, El Paso, TX, USA.
| |
Collapse
|
14
|
Lewis OL, Keener JP, Fogelson AL. Electrodiffusion-Mediated Swelling of a Two-Phase Gel Model of Gastric Mucus. Gels 2018; 4:gels4030076. [PMID: 30674852 PMCID: PMC6209243 DOI: 10.3390/gels4030076] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 08/27/2018] [Indexed: 11/16/2022] Open
Abstract
Gastric mucus gel is known to exhibit dramatic and unique swelling behaviors in response to the ionic composition of the hydrating solution. This swelling behavior is important in the maintenance of the mucus layer lining the stomach wall, as the layer is constantly digested by enzymes in the lumen, and must be replenished by new mucus that swells as it is secreted from the gastric wall. One hypothesis suggests that the condensed state of mucus at secretion is maintained by transient bonds with calcium that form crosslinks. These crosslinks are lost as monovalent cations from the environment displace divalent crosslinkers, leading to a dramatic change in the energy of the gel and inducing the swelling behavior. Previous modeling work has characterized the equilibrium behavior of polyelectrolyte gels that respond to calcium crosslinking. Here, we present an investigation of the dynamic swelling behavior of a polyelectrolytic gel model of mucus. In particular, we quantified the rate at which a globule of initially crosslinked gel swells when exposed to an ionic bath. The dependence of this swelling rate on several parameters was characterized. We observed that swelling rate has a non-monotone dependence on the molarity of the bath solution, with moderate concentrations of available sodium inducing the fastest swelling.
Collapse
Affiliation(s)
- Owen L Lewis
- Department of Mathematics, Florida State University, Tallahassee, FL 32306-4510, USA.
| | - James P Keener
- Departments of Mathematics and Bioengineering, University of Utah, Salt Lake City, UT 84112, USA.
| | - Aaron L Fogelson
- Departments of Mathematics and Bioengineering, University of Utah, Salt Lake City, UT 84112, USA.
| |
Collapse
|