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Morales N, Valdés-Muñoz E, González J, Valenzuela-Hormazábal P, Palma JM, Galarza C, Catagua-González Á, Yáñez O, Pereira A, Bustos D. Machine Learning-Driven Classification of Urease Inhibitors Leveraging Physicochemical Properties as Effective Filter Criteria. Int J Mol Sci 2024; 25:4303. [PMID: 38673888 PMCID: PMC11049951 DOI: 10.3390/ijms25084303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Revised: 04/03/2024] [Accepted: 04/08/2024] [Indexed: 04/28/2024] Open
Abstract
Urease, a pivotal enzyme in nitrogen metabolism, plays a crucial role in various microorganisms, including the pathogenic Helicobacter pylori. Inhibiting urease activity offers a promising approach to combating infections and associated ailments, such as chronic kidney diseases and gastric cancer. However, identifying potent urease inhibitors remains challenging due to resistance issues that hinder traditional approaches. Recently, machine learning (ML)-based models have demonstrated the ability to predict the bioactivity of molecules rapidly and effectively. In this study, we present ML models designed to predict urease inhibitors by leveraging essential physicochemical properties. The methodological approach involved constructing a dataset of urease inhibitors through an extensive literature search. Subsequently, these inhibitors were characterized based on physicochemical properties calculations. An exploratory data analysis was then conducted to identify and analyze critical features. Ultimately, 252 classification models were trained, utilizing a combination of seven ML algorithms, three attribute selection methods, and six different strategies for categorizing inhibitory activity. The investigation unveiled discernible trends distinguishing urease inhibitors from non-inhibitors. This differentiation enabled the identification of essential features that are crucial for precise classification. Through a comprehensive comparison of ML algorithms, tree-based methods like random forest, decision tree, and XGBoost exhibited superior performance. Additionally, incorporating the "chemical family type" attribute significantly enhanced model accuracy. Strategies involving a gray-zone categorization demonstrated marked improvements in predictive precision. This research underscores the transformative potential of ML in predicting urease inhibitors. The meticulous methodology outlined herein offers actionable insights for developing robust predictive models within biochemical systems.
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Affiliation(s)
- Natalia Morales
- Magíster en Ciencias de la Computación, Universidad Católica del Maule, Talca 3460000, Chile
| | - Elizabeth Valdés-Muñoz
- Doctorado en Biotecnología Traslacional, Centro de Biotecnología de los Recursos Naturales, Universidad Católica del Maule, Talca 3480094, Chile
| | - Jaime González
- Magíster en Ciencias de la Computación, Universidad Católica del Maule, Talca 3460000, Chile
| | | | - Jonathan M Palma
- Facultad de Ingeniería, Universidad de Talca, Curicó 3344158, Chile
| | - Christian Galarza
- Departamento de Matemáticas, Facultad de Ciencias Naturales y Matemáticas, Escuela Superior Politécnica del Litoral, Guayaquil EC090903, Ecuador
| | - Ángel Catagua-González
- Departamento de Matemáticas, Facultad de Ciencias Naturales y Matemáticas, Escuela Superior Politécnica del Litoral, Guayaquil EC090903, Ecuador
| | - Osvaldo Yáñez
- Núcleo de Investigación en Data Science, Facultad de Ingeniería y Negocios, Universidad de las Américas, Santiago 7500000, Chile
| | - Alfredo Pereira
- Facultad de Ingeniería, Arquitectura y Diseño, Universidad San Sebastián, Bellavista 7, Santiago 8420524, Chile
| | - Daniel Bustos
- Laboratorio de Bioinformática y Química Computacional, Departamento de Medicina Traslacional, Facultad de Medicina, Universidad Católica del Maule, Talca 3480094, Chile
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Valdes O, Bustos D, Guzmán L, Muñoz-Vera M, Urra G, Castro RI, Morales-Quintana L. The Controlled Release of Abscisic Acid (ABA) Utilizing Alginate-Chitosan Gel Blends: A Synergistic Approach for an Enhanced Small-Molecule Delivery Controller. Gels 2024; 10:185. [PMID: 38534603 DOI: 10.3390/gels10030185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 03/04/2024] [Accepted: 03/05/2024] [Indexed: 03/28/2024] Open
Abstract
The integration of abscisic acid (ABA) into a chitosan-alginate gel blend unveils crucial insights into the formation and stability of these two substances. ABA, a key phytohormone in plant growth and stress responses, is strategically targeted for controlled release within these complexes. This study investigates the design and characterization of this novel controlled-release system, showcasing the potential of alginate-chitosan gel blends in ABA delivery. Computational methods, including molecular dynamics simulations, are employed to analyze the structural effects of microencapsulation, offering valuable insights into complex behavior under varying conditions. This paper focuses on the controlled release of ABA from these complexes, highlighting its strategic importance in drug delivery systems and beyond. This controlled release enables targeted and regulated ABA delivery, with far-reaching implications for pharmaceuticals, agriculture, and plant stress response studies. While acknowledging context dependency, the paper suggests that the liberation or controlled release of ABA holds promise in applications, urging further research and experimentation to validate its utility across diverse fields. Overall, this work significantly contributes to understanding the characteristics and potential applications of chitosan-alginate complexes, marking a noteworthy advancement in the field of controlled-release systems.
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Affiliation(s)
- Oscar Valdes
- Centro de Investigación de Estudios Avanzados del Maule (CIEAM), Vicerrectoría de Investigación y Postgrado, Universidad Católica del Maule, Talca 3460000, Chile
| | - Daniel Bustos
- Laboratorio de Bioinformática y Química Computacional, Departamento de Medicina Traslacional, Facultad de Medicina, Universidad Católica del Maule, Talca 3480094, Chile
| | - Luis Guzmán
- Departamento de Bioquímica Clínica e Inmunohematología, Facultad de Ciencias de la Salud, Universidad de Talca, Avenida Lircay, s/n, Casilla 747-721, Talca 3460000, Chile
| | - Marcelo Muñoz-Vera
- Multidisciplinary Agroindustry Research Laboratory, Universidad Autónoma de Chile, Cinco Pte. N° 1670, Talca 3467987, Chile
| | - Gabriela Urra
- Laboratorio de Bioinformática y Química Computacional, Departamento de Medicina Traslacional, Facultad de Medicina, Universidad Católica del Maule, Talca 3480094, Chile
| | - Ricardo I Castro
- Multidisciplinary Agroindustry Research Laboratory, Instituto de Ciencias Aplicadas, Facultad de Arquitectura, Construcción y Medio Ambiente, Universidad Autónoma de Chile, Cinco Pte. N° 1670, Talca 3467987, Chile
| | - Luis Morales-Quintana
- Multidisciplinary Agroindustry Research Laboratory, Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Cinco Pte. N° 1670, Talca 3467987, Chile
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Valenzuela-Hormazabal P, Sepúlveda RV, Alegría-Arcos M, Valdés-Muñoz E, Rojas-Pérez V, González-Bonet I, Suardíaz R, Galarza C, Morales N, Leddermann V, Castro RI, Benso B, Urra G, Hernández-Rodríguez EW, Bustos D. Unveiling Novel Urease Inhibitors for Helicobacter pylori: A Multi-Methodological Approach from Virtual Screening and ADME to Molecular Dynamics Simulations. Int J Mol Sci 2024; 25:1968. [PMID: 38396647 PMCID: PMC10888695 DOI: 10.3390/ijms25041968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2023] [Revised: 01/20/2024] [Accepted: 01/25/2024] [Indexed: 02/25/2024] Open
Abstract
Helicobacter pylori (Hp) infections pose a global health challenge demanding innovative therapeutic strategies by which to eradicate them. Urease, a key Hp virulence factor hydrolyzes urea, facilitating bacterial survival in the acidic gastric environment. In this study, a multi-methodological approach combining pharmacophore- and structure-based virtual screening, molecular dynamics simulations, and MM-GBSA calculations was employed to identify novel inhibitors for Hp urease (HpU). A refined dataset of 8,271,505 small molecules from the ZINC15 database underwent pharmacokinetic and physicochemical filtering, resulting in 16% of compounds for pharmacophore-based virtual screening. Molecular docking simulations were performed in successive stages, utilizing HTVS, SP, and XP algorithms. Subsequent energetic re-scoring with MM-GBSA identified promising candidates interacting with distinct urease variants. Lys219, a residue critical for urea catalysis at the urease binding site, can manifest in two forms, neutral (LYN) or carbamylated (KCX). Notably, the evaluated molecules demonstrated different interaction and energetic patterns in both protein variants. Further evaluation through ADMET predictions highlighted compounds with favorable pharmacological profiles, leading to the identification of 15 candidates. Molecular dynamics simulations revealed comparable structural stability to the control DJM, with candidates 5, 8 and 12 (CA5, CA8, and CA12, respectively) exhibiting the lowest binding free energies. These inhibitors suggest a chelating capacity that is crucial for urease inhibition. The analysis underscores the potential of CA5, CA8, and CA12 as novel HpU inhibitors. Finally, we compare our candidates with the chemical space of urease inhibitors finding physicochemical similarities with potent agents such as thiourea.
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Affiliation(s)
- Paulina Valenzuela-Hormazabal
- Departamento de Farmacología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción 4030000, Chile;
| | - Romina V. Sepúlveda
- Center for Bioinformatics and Integrative Biology, Facultad de Ciencias de la Vida, Universidad Andres Bello, Av. República 330, Santiago 8370146, Chile;
| | - Melissa Alegría-Arcos
- Núcleo de Investigación en Data Science, Facultad de Ingeniería y Negocios, Universidad de las Américas, Santiago 7500000, Chile;
| | - Elizabeth Valdés-Muñoz
- Doctorado en Biotecnología Traslacional, Facultad de Ciencias Agrarias y Forestales, Universidad Católica del Maule, Talca 3480094, Chile; (E.V.-M.); (V.R.-P.)
| | - Víctor Rojas-Pérez
- Doctorado en Biotecnología Traslacional, Facultad de Ciencias Agrarias y Forestales, Universidad Católica del Maule, Talca 3480094, Chile; (E.V.-M.); (V.R.-P.)
| | - Ileana González-Bonet
- Biomedical Research Labs, Facultad de Medicina, Universidad Católica del Maule, Talca 3480094, Chile;
| | - Reynier Suardíaz
- Departamento de Química Física, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain;
| | - Christian Galarza
- Departamento de Matemáticas, Facultad de Ciencias Naturales y Matemáticas, Escuela Superior Politécnica del Litoral, Guayaquil 090112, Ecuador;
| | - Natalia Morales
- Magíster en Ciencias de la Computación, Universidad Católica del Maule, Talca 3460000, Chile; (N.M.); (V.L.)
| | - Verónica Leddermann
- Magíster en Ciencias de la Computación, Universidad Católica del Maule, Talca 3460000, Chile; (N.M.); (V.L.)
| | - Ricardo I. Castro
- Multidisciplinary Agroindustry Research Laboratory, Instituto de Ciencias Aplicadas, Facultad de Arquitectura, Construcción y Medio Ambiente, Universidad Autónoma de Chile, Cinco Pte. N°1670, Talca 3467987, Chile;
| | - Bruna Benso
- School of Dentistry, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago 7810000, Chile;
| | - Gabriela Urra
- Laboratorio de Bioinformática y Química Computacional, Departamento de Medicina Traslacional, Facultad de Medicina, Universidad Católica del Maule, Talca 3480094, Chile;
| | - Erix W. Hernández-Rodríguez
- Laboratorio de Bioinformática y Química Computacional, Departamento de Medicina Traslacional, Facultad de Medicina, Universidad Católica del Maule, Talca 3480094, Chile;
- Unidad de Bioinformática Clínica, Centro Oncológico, Facultad de Medicina, Universidad Católica del Maule, Talca 3480094, Chile
| | - Daniel Bustos
- Laboratorio de Bioinformática y Química Computacional, Departamento de Medicina Traslacional, Facultad de Medicina, Universidad Católica del Maule, Talca 3480094, Chile;
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Hormazábal-Abarza F, Bustos D, Rodríguez-Arriaza F, Sáez D, Urra G, Parra-Palma C, Méndez-Yáñez Á, Ramos P, Morales-Quintana L. Structural and transcriptional characterization of pyruvate decarboxylase (PDC) gene family during strawberry fruit ripening process. Plant Physiol Biochem 2024; 207:108417. [PMID: 38354527 DOI: 10.1016/j.plaphy.2024.108417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 01/17/2024] [Accepted: 02/01/2024] [Indexed: 02/16/2024]
Abstract
Strawberry is one of the most popular fruits in the world, because their high fruit quality, especially with respect to the combination of aroma, flavor, color, and nutritional compounds. Pyruvate decarboxylase (PDC) is the first of two enzymes specifically required for ethanolic fermentation and catalyzes the decarboxylation of pyruvate to yield acetaldehyde and CO2. The ethanol, an important alcohol which acts as a precursor for the ester and other alcohols formation in strawberry, is produced by the PDC. The objective was found all different PDCs genes present in the strawberry genome and investigate PDC gene expression and ligand-protein interactions in strawberry fruit. Volatile organic compounds were evaluated during the development of the fruit. After this, eight FaPDC were identified with four genes that increase the relative expression during fruit ripening process. Molecular dynamics simulations were performed to analyze the behavior of Pyr and TPP ligands within the catalytic and regulatory sites of the PDC proteins. Results indicated that energy-restrained simulations exhibited minor fluctuations in ligand-protein interactions, while unrestrained simulations revealed crucial insights into ligand affinity. TPP consistently displayed strong interactions with the catalytic site, emphasizing its pivotal role in enzymatic activity. However, FaPDC6 and FaPDC9 exhibited decreased pyruvate affinity initially, suggesting unique binding characteristics requiring further investigation. Finally, the present study contributes significantly to understanding PDC gene expression and the intricate molecular dynamics underlying strawberry fruit ripening, shedding light on potential targets for further research in this critical biological pathway.
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Affiliation(s)
- Francisca Hormazábal-Abarza
- Multidisciplinary Agroindustry Research Laboratory, Instituto de Ciencias Biomédicas, Facultad de Ciencias de La Salud, Universidad Autónoma de Chile, Cinco Poniente #1670 Talca, Región Del Maule, Chile
| | - Daniel Bustos
- Laboratorio de Bioinformática y Química Computacional, Departamento de Medicina Traslacional, Facultad de Medicina, Universidad Católica Del Maule, Talca, 3480094, Chile; Vicerrectoría de Investigación y Postgrado, Universidad Católica Del Maule, Talca, Chile
| | - Francisca Rodríguez-Arriaza
- Multidisciplinary Agroindustry Research Laboratory, Instituto de Ciencias Biomédicas, Facultad de Ciencias de La Salud, Universidad Autónoma de Chile, Cinco Poniente #1670 Talca, Región Del Maule, Chile
| | - Darwin Sáez
- Multidisciplinary Agroindustry Research Laboratory, Instituto de Ciencias Biomédicas, Facultad de Ciencias de La Salud, Universidad Autónoma de Chile, Cinco Poniente #1670 Talca, Región Del Maule, Chile; Programa de Doctorado en Ciencias Biomédicas, Instituto de Ciencias Biomédicas, Facultad de Ciencias de La Salud, Universidad Autónoma de Chile, Chile
| | - Gabriela Urra
- Vicerrectoría de Investigación y Postgrado, Universidad Católica Del Maule, Talca, Chile
| | - Carolina Parra-Palma
- Multidisciplinary Agroindustry Research Laboratory, Instituto de Ciencias Biomédicas, Facultad de Ciencias de La Salud, Universidad Autónoma de Chile, Cinco Poniente #1670 Talca, Región Del Maule, Chile
| | - Ángela Méndez-Yáñez
- Multidisciplinary Agroindustry Research Laboratory, Instituto de Ciencias Biomédicas, Facultad de Ciencias de La Salud, Universidad Autónoma de Chile, Cinco Poniente #1670 Talca, Región Del Maule, Chile
| | - Patricio Ramos
- Vicerrectoría de Investigación y Postgrado, Universidad Católica Del Maule, Talca, Chile; Plant Microorganism Interaction Laboratory, Instituto de Ciencias Biológicas, Universidad de Talca, Talca, Chile.
| | - Luis Morales-Quintana
- Multidisciplinary Agroindustry Research Laboratory, Instituto de Ciencias Biomédicas, Facultad de Ciencias de La Salud, Universidad Autónoma de Chile, Cinco Poniente #1670 Talca, Región Del Maule, Chile.
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Amaya-Rodriguez CA, Carvajal-Zamorano K, Bustos D, Alegría-Arcos M, Castillo K. A journey from molecule to physiology and in silico tools for drug discovery targeting the transient receptor potential vanilloid type 1 (TRPV1) channel. Front Pharmacol 2024; 14:1251061. [PMID: 38328578 PMCID: PMC10847257 DOI: 10.3389/fphar.2023.1251061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 12/14/2023] [Indexed: 02/09/2024] Open
Abstract
The heat and capsaicin receptor TRPV1 channel is widely expressed in nerve terminals of dorsal root ganglia (DRGs) and trigeminal ganglia innervating the body and face, respectively, as well as in other tissues and organs including central nervous system. The TRPV1 channel is a versatile receptor that detects harmful heat, pain, and various internal and external ligands. Hence, it operates as a polymodal sensory channel. Many pathological conditions including neuroinflammation, cancer, psychiatric disorders, and pathological pain, are linked to the abnormal functioning of the TRPV1 in peripheral tissues. Intense biomedical research is underway to discover compounds that can modulate the channel and provide pain relief. The molecular mechanisms underlying temperature sensing remain largely unknown, although they are closely linked to pain transduction. Prolonged exposure to capsaicin generates analgesia, hence numerous capsaicin analogs have been developed to discover efficient analgesics for pain relief. The emergence of in silico tools offered significant techniques for molecular modeling and machine learning algorithms to indentify druggable sites in the channel and for repositioning of current drugs aimed at TRPV1. Here we recapitulate the physiological and pathophysiological functions of the TRPV1 channel, including structural models obtained through cryo-EM, pharmacological compounds tested on TRPV1, and the in silico tools for drug discovery and repositioning.
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Affiliation(s)
- Cesar A. Amaya-Rodriguez
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
- Departamento de Fisiología y Comportamiento Animal, Facultad de Ciencias Naturales, Exactas y Tecnología, Universidad de Panamá, Ciudad de Panamá, Panamá
| | - Karina Carvajal-Zamorano
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Daniel Bustos
- Centro de Investigación de Estudios Avanzados del Maule (CIEAM), Vicerrectoría de Investigación y Postgrado Universidad Católica del Maule, Talca, Chile
- Laboratorio de Bioinformática y Química Computacional, Departamento de Medicina Traslacional, Facultad de Medicina, Universidad Católica del Maule, Talca, Chile
| | - Melissa Alegría-Arcos
- Núcleo de Investigación en Data Science, Facultad de Ingeniería y Negocios, Universidad de las Américas, Santiago, Chile
| | - Karen Castillo
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
- Centro de Investigación de Estudios Avanzados del Maule (CIEAM), Vicerrectoría de Investigación y Postgrado Universidad Católica del Maule, Talca, Chile
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Stevens-Sostre WA, Flores-Aldama L, Bustos D, Li J, Morais-Cabral JH, Delemotte L, Robertson GA. An intracellular hydrophobic nexus critical for hERG1 channel slow deactivation. Biophys J 2024:S0006-3495(24)00026-2. [PMID: 38219015 DOI: 10.1016/j.bpj.2024.01.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 11/17/2023] [Accepted: 01/09/2024] [Indexed: 01/15/2024] Open
Abstract
Slow deactivation is a critical property of voltage-gated K+ channels encoded by the human Ether-à-go-go-Related Gene 1 (hERG). hERG1 channel deactivation is modulated by interactions between intracellular N-terminal Per-Arnt-Sim (PAS) and C-terminal cyclic nucleotide-binding homology (CNBh) domains. The PAS domain is multipartite, comprising a globular domain (gPAS; residues 26-135) and an N-terminal PAS-cap that is further subdivided into an initial unstructured "tip" (residues 1-12) and an amphipathic α-helical region (residues 13-25). Although the PAS-cap tip has long been considered the effector of slow deactivation, how its position near the gating machinery is controlled has not been elucidated. Here, we show that a triad of hydrophobic interactions among the gPAS, PAS-cap α helix, and the CNBh domains is required to support slow deactivation in hERG1. The primary sequence of this "hydrophobic nexus" is highly conserved among mammalian ERG channels but shows key differences to fast-deactivating Ether-à-go-go 1 (EAG1) channels. Combining sequence analysis, structure-directed mutagenesis, electrophysiology, and molecular dynamics simulations, we demonstrate that polar serine substitutions uncover an intermediate deactivation mode that is also mimicked by deletion of the PAS-cap α helix. Molecular dynamics simulation analyses of the serine-substituted channels show an increase in distance among the residues of the hydrophobic nexus, a rotation of the intracellular gating ring, and a retraction of the PAS-cap tip from its receptor site near the voltage sensor domain and channel gate. These findings provide compelling evidence that the hydrophobic nexus coordinates the respective components of the intracellular gating ring and positions the PAS-cap tip to control hERG1 deactivation gating.
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Affiliation(s)
- Whitney A Stevens-Sostre
- Department of Neuroscience, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - Lisandra Flores-Aldama
- Department of Neuroscience, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - Daniel Bustos
- Centro de Investigación de Estudios Avanzados Del Maule (CIEAM), Vicerrectoría de Investigación y Postgrado, Universidad Católica Del Maule, Talca, Chile; Laboratorio de Bioinformática y Química Computacional (LBQC), Departamento de Medicina Traslacional, Facultad de Medicina, Universidad Católica Del Maule, Talca, Chile
| | - Jin Li
- Department of Neuroscience, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - João H Morais-Cabral
- Instituto de Investigação e Inovação Em Saude da Universidade Do Porto (i3S); Instituto de Biologia Molecular e Celular, Universidade Do Porto, Porto, Portugal
| | - Lucie Delemotte
- KTH Royal Institute of Technology, Science for Life Laboratory, Stockholm, Sweden
| | - Gail A Robertson
- Department of Neuroscience, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin.
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Allam S, Sartaj S, Moquim H, Husnain MA, Bustos D, Lakkimsetti M, Randhawa AK, Gupta I. Role of Liraglutide Use in Patients With Heart Failure. Cureus 2023; 15:e50065. [PMID: 38186489 PMCID: PMC10769535 DOI: 10.7759/cureus.50065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/06/2023] [Indexed: 01/09/2024] Open
Abstract
Heart failure is a clinical condition in which the heart is unable to maintain adequate cardiac output. Liraglutide is a glucagon-like peptide 1 (GLP-1) analogue that is used for the treatment of type 2 diabetes mellitus, but recent evidence suggests that it might have a beneficial role in treating heart failure. We conducted a review of existing literature and found five relevant studies. Data from these studies were extracted and then extrapolated into results following analysis. Four of the five studies found an increase in heart rate in heart failure patients. All five studies reported an increased rate of hospitalization. The five studies also showed an increased risk of adverse effects such as arrhythmia, ventricular tachycardia, atrial fibrillation, and worsening of heart failure. Given the scarcity of evidence in the available literature on liraglutide in heart failure, more research on this population is required.
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Affiliation(s)
- Sanjana Allam
- Internal Medicine, Gandhi Medical College, Secunderabad, IND
| | - Sahil Sartaj
- Internal Medicine, Melmaruvathur Adiparasakthi Institute of Medical Sciences and Research, Melmaruvathur, IND
| | - Hiba Moquim
- Internal Medicine, Shadan Institute of Medical Sciences, Hyderabad, IND
| | - Muhammad Ammar Husnain
- Internal Medicine, Combined Military Hospital Lahore Medical College and Institute of Dentistry, Lahore, PAK
| | - Daniel Bustos
- Internal Medicine, Pontifical Catholic University of Ecuador, Quito, ECU
| | | | - Avneet K Randhawa
- Internal Medicine, Maharishi Markandeshwar Institute of Medical Sciences and Research, Ambala, IND
| | - Ishita Gupta
- Internal Medicine, Dr. Rajendra Prasad Government Medical College, Tanda, Kangra, IND
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Bustos D, Guzmán L, Valdés O, Muñoz-Vera M, Morales-Quintana L, Castro RI. Development and Evaluation of Cross-Linked Alginate-Chitosan-Abscisic Acid Blend Gel. Polymers (Basel) 2023; 15:3217. [PMID: 37571107 PMCID: PMC10420979 DOI: 10.3390/polym15153217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 07/17/2023] [Accepted: 07/21/2023] [Indexed: 08/13/2023] Open
Abstract
Abscisic acid (ABA) has been proposed to play a significant role in the ripening of nonclimacteric fruit, stomatal opening, and response to abiotic stresses in plants, which can adversely affect crop growth and productivity. The biological effects of ABA are dependent on its concentration and signal transduction pathways. However, due to its susceptibility to the environment, it is essential to find a suitable biotechnological approach to coat ABA for its application. One promising approach is to utilize alginate and chitosan, two natural polysaccharides known for their strong affinity for water and their ability to act as coating agents. In this study, an alginate-chitosan blend was employed to develop an ABA cover. To achieve this, an alginate-chitosan-abscisic acid (ALG-CS-ABA) blend was prepared by forming ionic bonds or complexes with calcium ions, or through dual cross-linking. This was done by dripping a homogeneous solution of alginate-chitosan and ABA into a calcium chloride solution, resulting in the formation of the blend. By combining the unique properties of alginate, chitosan, and ABA, the resulting ALG-CS-ABA blend can potentially offer enhanced stability, controlled release, and improved protection of ABA. These characteristics make it a promising biotechnological approach for various applications, including the targeted delivery of ABA in agricultural practices or in the development of innovative plant-based products. Further evaluation and characterization of the ALG-CS-ABA blend will provide valuable insights into its potential applications in the fields of biomedicine, agriculture, and tissue engineering.
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Affiliation(s)
- Daniel Bustos
- Centro de Investigación de Estudios Avanzados del Maule (CIEAM), Vicerrectoría de Investigación y Postgrado, Universidad Católica del Maule, Talca 3460000, Chile; (D.B.); (O.V.)
- Laboratorio de Bioinformática y Química Computacional (LBQC), Escuela de Bioingeniería Médica, Facultad de Medicina, Universidad Católica del Maule, Talca 3460000, Chile
| | - Luis Guzmán
- Departamento de Bioquímica Clínica e Inmunohematología, Facultad de Ciencias de la Salud, Universidad de Talca, Avenida Lircay, s/n, Casilla 747–721, Talca 3460000, Chile;
| | - Oscar Valdés
- Centro de Investigación de Estudios Avanzados del Maule (CIEAM), Vicerrectoría de Investigación y Postgrado, Universidad Católica del Maule, Talca 3460000, Chile; (D.B.); (O.V.)
| | - Marcelo Muñoz-Vera
- Multidisciplinary Agroindustry Research Laboratory, Universidad Autónoma de Chile, Cinco Pte. N°1670, Talca 3467987, Chile;
| | - Luis Morales-Quintana
- Multidisciplinary Agroindustry Research Laboratory, Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Cinco Pte. N°1670, Talca 3467987, Chile
| | - Ricardo I. Castro
- Multidisciplinary Agroindustry Research Laboratory, Instituto de Ciencias Aplicadas, Facultad de Arquitectura, Construcción y Medio Ambiente, Universidad Autónoma de Chile, Cinco Pte. N°1670, Talca 3467987, Chile
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9
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Yáñez O, Alegría-Arcos M, Suardiaz R, Morales-Quintana L, Castro RI, Palma-Olate J, Galarza C, Catagua-González Á, Rojas-Pérez V, Urra G, Hernández-Rodríguez EW, Bustos D. Calcium-Alginate-Chitosan Nanoparticle as a Potential Solution for Pesticide Removal, a Computational Approach. Polymers (Basel) 2023; 15:3020. [PMID: 37514411 PMCID: PMC10383139 DOI: 10.3390/polym15143020] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 07/06/2023] [Accepted: 07/10/2023] [Indexed: 07/30/2023] Open
Abstract
Pesticides have a significant negative impact on the environment, non-target organisms, and human health. To address these issues, sustainable pest management practices and government regulations are necessary. However, biotechnology can provide additional solutions, such as the use of polyelectrolyte complexes to encapsulate and remove pesticides from water sources. We introduce a computational methodology to evaluate the capture capabilities of Calcium-Alginate-Chitosan (CAC) nanoparticles for a broad range of pesticides. By employing ensemble-docking and molecular dynamics simulations, we investigate the intermolecular interactions and absorption/adsorption characteristics between the CAC nanoparticles and selected pesticides. Our findings reveal that charged pesticide molecules exhibit more than double capture rates compared to neutral counterparts, owing to their stronger affinity for the CAC nanoparticles. Non-covalent interactions, such as van der Waals forces, π-π stacking, and hydrogen bonds, are identified as key factors which stabilized the capture and physisorption of pesticides. Density profile analysis confirms the localization of pesticides adsorbed onto the surface or absorbed into the polymer matrix, depending on their chemical nature. The mobility and diffusion behavior of captured compounds within the nanoparticle matrix is assessed using mean square displacement and diffusion coefficients. Compounds with high capture levels exhibit limited mobility, indicative of effective absorption and adsorption. Intermolecular interaction analysis highlights the significance of hydrogen bonds and electrostatic interactions in the pesticide-polymer association. Notably, two promising candidates, an antibiotic derived from tetracycline and a rodenticide, demonstrate a strong affinity for CAC nanoparticles. This computational methodology offers a reliable and efficient screening approach for identifying effective pesticide capture agents, contributing to the development of eco-friendly strategies for pesticide removal.
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Affiliation(s)
- Osvaldo Yáñez
- Núcleo de Investigación en Data Science, Facultad de Ingeniería y Negocios, Universidad de las Américas, Santiago 7500000, Chile
| | - Melissa Alegría-Arcos
- Núcleo de Investigación en Data Science, Facultad de Ingeniería y Negocios, Universidad de las Américas, Santiago 7500000, Chile
| | - Reynier Suardiaz
- Departamento de Química Física, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Luis Morales-Quintana
- Multidisciplinary Agroindustry Research Laboratory, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Talca 3400000, Chile
| | - Ricardo I Castro
- Multidisciplinary Agroindustry Research Laboratory, Carrera de Ingeniería en Construcción, Instituto de Ciencias Químicas Aplicadas, Universidad Autónoma de Chile, Talca 3400000, Chile
| | | | - Christian Galarza
- Escuela Superior Politécnica del Litoral, Guayaquil EC090903, Ecuador
| | | | - Víctor Rojas-Pérez
- Doctorado en Biotecnología Traslacional, Facultad de Ciencias Agrarias y Forestales, Universidad Católica del Maule, Talca 3480094, Chile
| | - Gabriela Urra
- Laboratorio de Bioinformática y Química Computacional, Departamento de Medicina Traslacional, Facultad de Medicina, Universidad Católica del Maule, Talca 3480094, Chile
| | - Erix W Hernández-Rodríguez
- Laboratorio de Bioinformática y Química Computacional, Departamento de Medicina Traslacional, Facultad de Medicina, Universidad Católica del Maule, Talca 3480094, Chile
- Unidad de Bioinformática Clínica, Centro Oncológico, Facultad de Medicina, Universidad Católica del Maule, Talca 3480094, Chile
| | - Daniel Bustos
- Laboratorio de Bioinformática y Química Computacional, Departamento de Medicina Traslacional, Facultad de Medicina, Universidad Católica del Maule, Talca 3480094, Chile
- Centro de Investigación de Estudios Avanzados del Maule (CIEAM), Vicerrectoría de Investigación y Postgrado Universidad Católica del Maule, Talca 3460000, Chile
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10
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Bustos D, Galarza C, Ordoñez W, Brauchi S, Benso B. Cost-Effective Pipeline for a Rational Design and Selection of Capsaicin Analogues Targeting TRPV1 Channels. ACS Omega 2023; 8:11736-11749. [PMID: 37033853 PMCID: PMC10077575 DOI: 10.1021/acsomega.2c05672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 11/25/2022] [Indexed: 06/19/2023]
Abstract
Transient receptor potential (TRP) channels constitute a large group of membrane receptors associated with sensory pathways in vertebrates. One of the most studied is TRPV1, a polymodal receptor tuned for detecting heat and pungent compounds. Specific inhibition of the nociceptive transduction at the peripheral nerve represents a convenient approach to pain relief. While acting as a chemoreceptor, TRPV1 shows high sensitivity and selectivity for capsaicin. In contrast to the drugs available on the market that target the inflammatory system, TRPV1 antagonists act as negative modulators of nociceptive transduction. Therefore, the development of compounds modulating TRPV1 activity has expanded dramatically over time. Experimental data suggest that most agonist and antagonist drugs interact at or near capsaicin's binding site. In particular, the properties of capsaicin's head play an essential role in modulating potency and affinity. Here, we explored a cost-efficient pipeline to predict the effects of introducing chemical modifications into capsaicin's head region. An extensive set of molecules was selected by first considering the geometrical properties of capsaicin's binding site and then molecular docking. Finally, the novel ligands were ranked by combining molecular and pharmacokinetic predictions.
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Affiliation(s)
- Daniel Bustos
- Centro
de Investigación de Estudios Avanzados del Maule (CIEAM), Vicerrectoría
de Investigación y Postgrado, Universidad
Católica del Maule, Talca 3460000, Chile
- Laboratorio
de Bioinformática y Química Computacional, Departamento
de Medicina Traslacional, Facultad de Medicina, Universidad Católica del Maule, Talca 3480094, Chile
| | - Christian Galarza
- Facultad
de Ciencias Naturales y Matemáticas, Escuela Superior Politécnica del Litoral, ESPOL, Guayaquil 090703, Ecuador
| | - Wilson Ordoñez
- Facultad
de Ciencias Naturales y Matemáticas, Escuela Superior Politécnica del Litoral, ESPOL, Guayaquil 090703, Ecuador
| | - Sebastian Brauchi
- Department
of Physiology, Faculty of Medicine, Universidad
Austral de Chile, Valdivia 5090000, Chile
- Millennium
Nucleus of Ion Channels Associated Diseases (MiNICAD), 8330024, Chile
| | - Bruna Benso
- Millennium
Nucleus of Ion Channels Associated Diseases (MiNICAD), 8330024, Chile
- School of
Dentistry, Faculty of Medicine, Pontificia
Universidad Católica de Chile, Santiago 8330024, Chile
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11
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Arévalo B, Bedoya M, Kiper AK, Vergara F, Ramírez D, Mazola Y, Bustos D, Zúñiga R, Cikutovic R, Cayo A, Rinné S, Ramirez-Apan MT, Sepúlveda FV, Cerda O, López-Collazo E, Decher N, Zúñiga L, Gutierrez M, González W. Selective TASK-1 Inhibitor with a Defined Structure–Activity Relationship Reduces Cancer Cell Proliferation and Viability. J Med Chem 2022; 65:15014-15027. [DOI: 10.1021/acs.jmedchem.1c00378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Bárbara Arévalo
- Centro de Estudios en Alimentos Procesados−CEAP, Conicyt, Programa Regional R19A10001, Gore Maule, 3460000 Talca, Chile
| | - Mauricio Bedoya
- Centro de Investigación de Estudios Avanzados del Maule (CIEAM), Vicerrectoría de Investigación y Postgrado, Universidad Católica del Maule, 3460000 Talca, Chile
- Laboratorio de Bioinformática y Química Computacional, Departamento de Medicina Traslacional, Facultad de Medicina, Universidad Católica del Maule, 3480094 Talca, Chile
| | - Aytug K. Kiper
- Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg, Deutschhausstraße 1-2, 35037 Marburg, Germany
| | - Fernando Vergara
- Centro de Bioinformática, Simulación y Modelado (CBSM), Facultad de Ingeniería, Universidad de Talca, 1 Poniente No. 1141, 3460000 Talca, Chile
| | - David Ramírez
- Departamento de Farmacología, Facultad de Ciencias Biológicas, Universidad de Concepción, 4030000 Concepción, Chile
| | - Yuliet Mazola
- Centro de Bioinformática, Simulación y Modelado (CBSM), Facultad de Ingeniería, Universidad de Talca, 1 Poniente No. 1141, 3460000 Talca, Chile
| | - Daniel Bustos
- Centro de Investigación de Estudios Avanzados del Maule (CIEAM), Vicerrectoría de Investigación y Postgrado, Universidad Católica del Maule, 3460000 Talca, Chile
- Laboratorio de Bioinformática y Química Computacional (LBQC), Escuela de Química y Farmacia, Facultad de Medicina, Universidad Católica del Maule, 3460000 Talca, Chile
| | - Rafael Zúñiga
- Centro de Nanomedicina, Diagnóstico y Desarrollo de Fármacos (ND3), Laboratorio de Fisiología Molecular, Escuela de Medicina, Universidad de Talca, Casilla, 3460000 Talca, Chile
- Instituto de Investigación Interdisciplinaria, Vicerrectoría Académica, Universidad de Talca, 3460000 Talca, Chile
| | - Rocio Cikutovic
- Centro de Nanomedicina, Diagnóstico y Desarrollo de Fármacos (ND3), Laboratorio de Fisiología Molecular, Escuela de Medicina, Universidad de Talca, Casilla, 3460000 Talca, Chile
| | - Angel Cayo
- Centro de Nanomedicina, Diagnóstico y Desarrollo de Fármacos (ND3), Laboratorio de Fisiología Molecular, Escuela de Medicina, Universidad de Talca, Casilla, 3460000 Talca, Chile
| | - Susanne Rinné
- Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg, Deutschhausstraße 1-2, 35037 Marburg, Germany
| | - M. Teresa Ramirez-Apan
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, 04510, Coyoacán, 04510 México, DF, México
| | - Francisco V. Sepúlveda
- Centro de Estudios Científicos (CECs), 5110466 Valdivia, Chile
- Facultad de Medicina y Ciencia, Universidad San Sebastián, 5110466 Valdivia, Chile
| | - Oscar Cerda
- Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, 8380453 Santiago, Chile
- Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Facultad de Medicina, Universidad de Chile, 8380453 Santiago, Chile
| | - Eduardo López-Collazo
- The Innate Immune Response Group and Tumor Immunology Laboratory, IdiPAZ, La Paz University Hospital, 8046 Madrid, Spain
| | - Niels Decher
- Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg, Deutschhausstraße 1-2, 35037 Marburg, Germany
- Marburg Center for Mind, Brain and Behavior−MCMBB, Philipps-University Marburg, 35037 Marburg, Germany
| | - Leandro Zúñiga
- Centro de Nanomedicina, Diagnóstico y Desarrollo de Fármacos (ND3), Laboratorio de Fisiología Molecular, Escuela de Medicina, Universidad de Talca, Casilla, 3460000 Talca, Chile
| | - Margarita Gutierrez
- Laboratorio de Síntesis y Actividad Biológica, Instituto de Química de Recursos Naturales, Universidad de Talca, 1 poniente No. 1141, 3460000 Talca, Chile
| | - Wendy González
- Centro de Bioinformática, Simulación y Modelado (CBSM), Facultad de Ingeniería, Universidad de Talca, 1 Poniente No. 1141, 3460000 Talca, Chile
- Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Universidad de Talca, 1 Poniente No. 1141, 3460000 Talca, Chile
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12
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Bustos D, Hernández-Rodríguez EW, Poblete H, Alzate-Morales J, Challier C, Boetsch C, Vergara-Jaque A, Beassoni P. Structural Insights into the Inhibition Site in the Phosphorylcholine Phosphatase Enzyme of Pseudomonas aeruginosa. J Chem Inf Model 2022; 62:3067-3078. [PMID: 35670773 DOI: 10.1021/acs.jcim.2c00059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Pseudomonas aeruginosa is a highly pathogenic Gram-negative microorganism associated with high mortality levels in burned or immunosuppressed patients or individuals affected by cystic fibrosis. Studies support a colonization mechanism whereby P. aeruginosa can breakdown the host cell membrane phospholipids through the sequential action of two enzymes: (I) hemolytic phospholipase C acting upon phosphatidylcholine or sphingomyelin to produce phosphorylcholine (Pcho) and (II) phosphorylcholine phosphatase (PchP) that hydrolyzes Pcho to generate choline and inorganic phosphate. This coordinated action provides the bacteria with carbon, nitrogen, and inorganic phosphate to support growth. Furthermore, PchP exhibits a distinctive inhibition mechanism by high substrate concentration. Here, we combine kinetic assays and computational approaches such as molecular docking, molecular dynamics, and free-energy calculations to describe the inhibitory site of PchP, which shares specific residues with the enzyme's active site. Our study provides insights into a coupled inhibition mechanism by the substrate, allowing us to postulate that the integrity of the inhibition site is needed to the correct functioning of the active site. Our results allow us to gain a better understanding of PchP function and provide the basis for a rational drug design that might contribute to the treatment of infections caused by this important opportunistic pathogen.
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Affiliation(s)
- Daniel Bustos
- Centro de Investigación de Estudios Avanzados del Maule (CIEAM), Vicerrectoría de Investigación y Postgrado, Universidad Católica del Maule, Talca 3460000, Chile.,Laboratorio de Bioinformática y Química Computacional, Departamento de Medicina Traslacional, Facultad de Medicina, Universidad Católica del Maule, Talca 3480094, Chile
| | - Erix W Hernández-Rodríguez
- Laboratorio de Bioinformática y Química Computacional, Departamento de Medicina Traslacional, Facultad de Medicina, Universidad Católica del Maule, Talca 3480094, Chile.,Escuela de Química y Farmacia, Facultad de Medicina, Universidad Católica del Maule, Talca 3460000, Chile
| | - Horacio Poblete
- Center for Bioinformatics, Simulation and Modeling (CBSM), Faculty of Engineering, Universidad de Talca, 1 Poniente 1141, Talca 3465548, Chile.,Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Universidad de Talca, Talca 3465548, Chile
| | - Jans Alzate-Morales
- Center for Bioinformatics, Simulation and Modeling (CBSM), Faculty of Engineering, Universidad de Talca, 1 Poniente 1141, Talca 3465548, Chile
| | - Cecilia Challier
- Instituto para el Desarrollo Agroindustrial y de la Salud (IDAS), CONICET, Departamento de Química, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto (UNRC), Río Cuarto X5804BYA, Córdoba, Argentina
| | - Cristhian Boetsch
- Instituto de Biotecnología Ambiental y Salud (INBIAS), CONICET, Departamento de Biología Molecular, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto (UNRC), Río Cuarto X5804BYA, Córdoba, Argentina
| | - Ariela Vergara-Jaque
- Center for Bioinformatics, Simulation and Modeling (CBSM), Faculty of Engineering, Universidad de Talca, 1 Poniente 1141, Talca 3465548, Chile.,Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Universidad de Talca, Talca 3465548, Chile
| | - Paola Beassoni
- Instituto de Biotecnología Ambiental y Salud (INBIAS), CONICET, Departamento de Biología Molecular, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto (UNRC), Río Cuarto X5804BYA, Córdoba, Argentina
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13
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Valdés C, Valdés O, Bustos D, Abril D, Cabrera-Barjas G, Pereira A, Villaseñor J, Polo-Cuadrado E, Carreño G, Durán-Lara EF, Marican A. Use of Poly(vinyl alcohol)-Malic Acid (CLHPMA) Hydrogels and Chitosan Coated Calcium Alginate (CCCA) Microparticles as Potential Sorbent Phases for the Extraction and Quantitative Determination of Pesticides from Aqueous Solutions. Polymers (Basel) 2021; 13:3993. [PMID: 34833292 PMCID: PMC8619381 DOI: 10.3390/polym13223993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 11/13/2021] [Accepted: 11/14/2021] [Indexed: 11/16/2022] Open
Abstract
Pesticides are used worldwide to increase crop yields in agriculture. However, their toxicity and accumulation capacity can make them toxic to the environment, animals and humans. In the case of workers chronically exposed to these substances, they must be sampled continuously, so urine is an excellent option. In this sense, this study proposes to use poly(vinyl alcohol)-malic acid hydrogels, and chitosan-coated calcium alginate as new sorbent phases to be used in pesticide determination processes in urine. To better understand the behavior of these materials in the capture and desorption process, molecular dynamics simulations (MDS) were used, and desorption experiments were performed, using mechanical agitation, ultrasound, and pH variation in the desorption process, in order to optimize the parameters to obtain better recoveries. Under the optimal experimental conditions, the maximum recoveries were of the order of 11% (CFN), 3% (KCF), 53% (DMT), 18% (MTD) and 35% (MTL). Although the recoveries were not exhaustive, they are a first approximation for the use of these new sorbent phases in the determination of this type of compound in aqueous solutions and urine.
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Affiliation(s)
- Cristian Valdés
- Centro de Investigación de Estudios Avanzados del Maule (CIEAM), Vicerrectoria de Investigación y Postgrado, Universidad Católica del Maule, Talca 3460000, Chile; (C.V.); (O.V.); (D.B.)
| | - Oscar Valdés
- Centro de Investigación de Estudios Avanzados del Maule (CIEAM), Vicerrectoria de Investigación y Postgrado, Universidad Católica del Maule, Talca 3460000, Chile; (C.V.); (O.V.); (D.B.)
| | - Daniel Bustos
- Centro de Investigación de Estudios Avanzados del Maule (CIEAM), Vicerrectoria de Investigación y Postgrado, Universidad Católica del Maule, Talca 3460000, Chile; (C.V.); (O.V.); (D.B.)
- Laboratorio de Bioinformática y Química Computacional (LBQC), Facultad de Medicina, Universidad Católica del Maule, Talca 3460000, Chile
- Escuela de Bioingeniería Médica, Facultad de Medicina, Universidad Católica del Maule, Talca 3460000, Chile
| | - Diana Abril
- Departamento de Biología y Química, Facultad de Ciencias Básicas, Universidad Católica del Maule, Talca 3460000, Chile;
| | - Gustavo Cabrera-Barjas
- Unidad de Desarrollo Tecnológico (UDT), Universidad de Concepción, Parque Industrial Coronel, Coronel 3349001, Chile;
| | - Alfredo Pereira
- Instituto de Química de Recursos Naturales, Universidad de Talca, Talca 3460000, Maule, Chile; (A.P.); (J.V.); (E.P.-C.); (G.C.)
| | - Jorge Villaseñor
- Instituto de Química de Recursos Naturales, Universidad de Talca, Talca 3460000, Maule, Chile; (A.P.); (J.V.); (E.P.-C.); (G.C.)
| | - Efraín Polo-Cuadrado
- Instituto de Química de Recursos Naturales, Universidad de Talca, Talca 3460000, Maule, Chile; (A.P.); (J.V.); (E.P.-C.); (G.C.)
| | - Gustavo Carreño
- Instituto de Química de Recursos Naturales, Universidad de Talca, Talca 3460000, Maule, Chile; (A.P.); (J.V.); (E.P.-C.); (G.C.)
- Bio and NanoMaterials Lab, Drug Delivery and Controlled Release, Universidad de Talca, Talca 3460000, Maule, Chile
| | - Esteban F. Durán-Lara
- Bio and NanoMaterials Lab, Drug Delivery and Controlled Release, Universidad de Talca, Talca 3460000, Maule, Chile
- Departamento de Microbiología, Facultad de Ciencias de la Salud, Universidad de Talca, Talca 3460000, Maule, Chile
| | - Adolfo Marican
- Instituto de Química de Recursos Naturales, Universidad de Talca, Talca 3460000, Maule, Chile; (A.P.); (J.V.); (E.P.-C.); (G.C.)
- Bio and NanoMaterials Lab, Drug Delivery and Controlled Release, Universidad de Talca, Talca 3460000, Maule, Chile
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14
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Angel M, Blanco A, Losco F, Bustos D. Neoplasias del tracto genitourinario: historia de los grandes avances. Medicina (B Aires) 2021. [DOI: 10.56050/01205498.1568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Se presenta una reseña histórica de los avances en oncología en tumores genitourinarios. Avances que, desde su incorporación al arsenal terapéutico, no se modificaron hasta la actualidad. Y muchos de ellos son usados en otros modelos tumorales.
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15
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Aldama LF, Bustos D, Gonzalez W, Brauchi SE. A Structural Triad That Modulates Fast Inactivation in Calcium-Selective TRP Channels. Biophys J 2020. [DOI: 10.1016/j.bpj.2019.11.2330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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16
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Bustos D, Bedoya M, Ramírez D, Concha G, Zúñiga L, Decher N, Hernández-Rodríguez EW, Sepúlveda FV, Martínez L, González W. Elucidating the Structural Basis of the Intracellular pH Sensing Mechanism of TASK-2 K 2P Channels. Int J Mol Sci 2020; 21:ijms21020532. [PMID: 31947679 PMCID: PMC7013731 DOI: 10.3390/ijms21020532] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 12/25/2019] [Accepted: 01/08/2020] [Indexed: 11/23/2022] Open
Abstract
Two-pore domain potassium (K2P) channels maintain the cell’s background conductance by stabilizing the resting membrane potential. They assemble as dimers possessing four transmembrane helices in each subunit. K2P channels were crystallized in “up” and “down” states. The movements of the pore-lining transmembrane TM4 helix produce the aperture or closure of side fenestrations that connect the lipid membrane with the central cavity. When the TM4 helix is in the up-state, the fenestrations are closed, while they are open in the down-state. It is thought that the fenestration states are related to the activity of K2P channels and the opening of the channels preferentially occurs from the up-state. TASK-2, a member of the TALK subfamily of K2P channels, is opened by intracellular alkalization leading the deprotonation of the K245 residue at the end of the TM4 helix. This charge neutralization of K245 could be sensitive or coupled to the fenestration state. Here, we describe the relationship between the states of the intramembrane fenestrations and K245 residue in TASK-2 channel. By using molecular modeling and simulations, we show that the protonated state of K245 (K245+) favors the open fenestration state and, symmetrically, that the open fenestration state favors the protonated state of the lysine residue. We show that the channel can be completely blocked by Prozac, which is known to induce fenestration opening in TREK-2. K245 protonation and fenestration aperture have an additive effect on the conductance of the channel. The opening of the fenestrations with K245+ increases the entrance of lipids into the selectivity filter, blocking the channel. At the same time, the protonation of K245 introduces electrostatic potential energy barriers to ion entrance. We computed the free energy profiles of ion penetration into the channel in different fenestration and K245 protonation states, to show that the effects of the two transformations are summed up, leading to maximum channel blocking. Estimated rates of ion transport are in qualitative agreement with experimental results and support the hypothesis that the most important barrier for ion transport under K245+ and open fenestration conditions is the entrance of the ions into the channel.
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Affiliation(s)
- Daniel Bustos
- Centro de Bioinformática y Simulación Molecular, Universidad de Talca, Talca 3460000, Chile; (D.B.); (M.B.)
- Departamento de Computación e Industrias, Facultad de Ciencias de la Ingeniería, Universidad Católica del Maule, Talca 3460000, Chile
| | - Mauricio Bedoya
- Centro de Bioinformática y Simulación Molecular, Universidad de Talca, Talca 3460000, Chile; (D.B.); (M.B.)
| | - David Ramírez
- Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Santiago 8380453, Chile;
| | - Guierdy Concha
- Centro de Investigaciones Médicas, Escuela de Medicina, Universidad de Talca, Talca 3460000, Chile; (G.C.); (L.Z.)
- Magíster en Gestión de Operaciones, Facultad de Ingeniería (Campus Los Niches), Universidad de Talca, Talca 3460000, Chile
| | - Leandro Zúñiga
- Centro de Investigaciones Médicas, Escuela de Medicina, Universidad de Talca, Talca 3460000, Chile; (G.C.); (L.Z.)
- Programa de Investigación Asociativa en Cáncer Gástrico (PIA-CG), Universidad de Talca, Talca 3460000, Chile
| | - Niels Decher
- Institute for Physiology and Pathophysiology, Vegetative Physiology, University of Marburg, D-35037 Marburg, Germany;
| | | | - Francisco V. Sepúlveda
- Centro de Estudios Científicos (CECs), Avenida Arturo Prat 514, Valdivia 5110466, Chile
- Correspondence: (F.V.S.); (L.M.); (W.G.)
| | - Leandro Martínez
- Institute of Chemistry and Center for Computing in Engineering & Science, University of Campinas, Campinas 13083-861 SP, Brazil
- Correspondence: (F.V.S.); (L.M.); (W.G.)
| | - Wendy González
- Centro de Bioinformática y Simulación Molecular, Universidad de Talca, Talca 3460000, Chile; (D.B.); (M.B.)
- Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Universidad de Talca, Talca 3460000, Chile
- Correspondence: (F.V.S.); (L.M.); (W.G.)
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17
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Concha G, Bustos D, Zúñiga R, Catalán MA, Zúñiga L. Correction: Concha, G., et al. The Insensitivity of TASK-3 K 2P Channels to External Tetraethylammonium (TEA) Partially Depends on the Cap Structure. Int. J. Mol. Sci. 2018, 19, 2437. Int J Mol Sci 2019; 20:ijms20184651. [PMID: 31546836 PMCID: PMC6770687 DOI: 10.3390/ijms20184651] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 09/15/2019] [Indexed: 11/17/2022] Open
Affiliation(s)
- Guierdy Concha
- Centro de Investigaciones Médicas (CIM), Programa de Investigación Asociativa en Cáncer Gástrico (PIA-CG), Escuela de Medicina, Universidad de Talca, Talca 3460000, Chile.
- Magíster en Gestión de Operaciones, Facultad de Ingeniería (Campus Los Niches), Universidad de Talca, Talca 3460000, Chile.
| | - Daniel Bustos
- Centro de Investigaciones Médicas (CIM), Programa de Investigación Asociativa en Cáncer Gástrico (PIA-CG), Escuela de Medicina, Universidad de Talca, Talca 3460000, Chile.
- CBSM y Doctorado en Ciencias, mención Modelado de Sistemas Químicos y Biológicos, Facultad de Ingeniería, Universidad de Talca, Talca 3460000, Chile.
| | - Rafael Zúñiga
- Centro de Investigaciones Médicas (CIM), Programa de Investigación Asociativa en Cáncer Gástrico (PIA-CG), Escuela de Medicina, Universidad de Talca, Talca 3460000, Chile.
| | - Marcelo A Catalán
- Laboratorio de Fisiología Epitelial, Facultad de Ciencias de la Salud, Universidad Arturo Prat, Iquique 1130000, Chile.
| | - Leandro Zúñiga
- Centro de Investigaciones Médicas (CIM), Programa de Investigación Asociativa en Cáncer Gástrico (PIA-CG), Escuela de Medicina, Universidad de Talca, Talca 3460000, Chile.
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18
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Benso B, Bustos D, Zarraga MO, Gonzalez W, Caballero J, Brauchi S. Chalcone derivatives as non-canonical ligands of TRPV1. Int J Biochem Cell Biol 2019; 112:18-23. [PMID: 31026506 DOI: 10.1016/j.biocel.2019.04.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 04/18/2019] [Accepted: 04/22/2019] [Indexed: 10/27/2022]
Abstract
Transient receptor potential vanilloid 1 (TRPV1) is a polymodal cation channel activated by heat, voltage, and ligands. Also known as the capsaicin receptor, TRPV1 is expressed in numerous tissues by different cell types, including peripheral sensory fibers where acts as a thermal and chemical detector in nociceptive pathways. TRPV1 channels are able to bind a wide range of ligands, including a number of vanilloid derivatives all modulating channel's activity. When expressed by sensory neurons, activation of TRPV1 channels by heat (>40 °C), capsaicin (sub-micromolar), or acid environment (pH < 6), causes depolarization leading to burning pain sensation in mammals. Naturally occurring chalcones (1,3-diaryl-2-propen-1-ones) have been reported as effective inhibitors of TRPV1. Their relatively simple chemical structure and the possibility for handy chemical modification make them attractive ligands for the treatment of peripheral pain. By taking advantage of the structural information available, here we discuss pharmacological properties of chalcones and their putative mechanism of binding to TRPV1 channels.
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Affiliation(s)
- Bruna Benso
- School of Dentistry, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, RM, Chile; Department of Physiology, Faculty of Medicine, Universidad Austral de Chile, Valdivia, Chile; Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Valdivia, Chile
| | - Daniel Bustos
- Center for Bioinformatics and Molecular Simulation (CBSM), Universidad de Talca, Talca, Chile
| | - Miguel O Zarraga
- Department of Organic Chemistry, Faculty of Chemical Sciences, Universidad de Concepcion, Concepcion, Chile
| | - Wendy Gonzalez
- Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Valdivia, Chile; Center for Bioinformatics and Molecular Simulation (CBSM), Universidad de Talca, Talca, Chile
| | - Julio Caballero
- Center for Bioinformatics and Molecular Simulation (CBSM), Universidad de Talca, Talca, Chile
| | - Sebastian Brauchi
- Department of Physiology, Faculty of Medicine, Universidad Austral de Chile, Valdivia, Chile; Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Valdivia, Chile.
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19
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Flores Aldama L, Zavala K, Bustos D, Gonzalez W, Opazo J, Brauchi SE. Approaching to the Molecular Mechanism of the Fast Inactivation of Calcium Selective TRP Channels. Biophys J 2019. [DOI: 10.1016/j.bpj.2018.11.2437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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20
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Concha G, Bustos D, Zúñiga R, Catalán MA, Zúñiga L. The Insensitivity of TASK-3 K₂P Channels to External Tetraethylammonium (TEA) Partially Depends on the Cap Structure. Int J Mol Sci 2018; 19:ijms19082437. [PMID: 30126179 PMCID: PMC6121469 DOI: 10.3390/ijms19082437] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 08/10/2018] [Accepted: 08/13/2018] [Indexed: 01/12/2023] Open
Abstract
Two-pore domain K⁺ channels (K₂P) display a characteristic extracellular cap structure formed by two M1-P1 linkers, the functional role of which is poorly understood. It has been proposed that the presence of the cap explains the insensitivity of K₂P channels to several K⁺ channel blockers including tetraethylammonium (TEA). We have explored this hypothesis using mutagenesis and functional analysis, followed by molecular simulations. Our results show that the deletion of the cap structure of TASK-3 (TWIK-related acid-sensitive K⁺ channel) generates a TEA-sensitive channel with an IC50 of 11.8 ± 0.4 mM. The enhanced sensitivity to TEA displayed by the cap-less channel is also explained by the presence of an extra tyrosine residue at position 99. These results were corroborated by molecular simulation analysis, which shows an increased stability in the binding of TEA to the cap-less channel when a ring of four tyrosine is present at the external entrance of the permeation pathway. Consistently, Y99A or Y205A single-residue mutants generated in a cap-less channel backbone resulted in TASK-3 channels with low affinity to external TEA.
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Affiliation(s)
- Guierdy Concha
- Centro de Investigaciones Médicas (CIM), Programa de Investigación Asociativa en Cáncer Gástrico (PIA-CG), Escuela de Medicina, Universidad de Talca, Talca 3460000, Chile.
| | - Daniel Bustos
- Centro de Investigaciones Médicas (CIM), Programa de Investigación Asociativa en Cáncer Gástrico (PIA-CG), Escuela de Medicina, Universidad de Talca, Talca 3460000, Chile.
| | - Rafael Zúñiga
- Centro de Investigaciones Médicas (CIM), Programa de Investigación Asociativa en Cáncer Gástrico (PIA-CG), Escuela de Medicina, Universidad de Talca, Talca 3460000, Chile.
| | - Marcelo A Catalán
- Laboratorio de Fisiología Epitelial, Facultad de Ciencias de la Salud, Universidad Arturo Prat, Iquique 1130000, Chile.
| | - Leandro Zúñiga
- Centro de Investigaciones Médicas (CIM), Programa de Investigación Asociativa en Cáncer Gástrico (PIA-CG), Escuela de Medicina, Universidad de Talca, Talca 3460000, Chile.
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21
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Flores Aldama L, Bustos D, Opazo JG, González W, Brauchi S. Evolutionary Variations in HLH Domain Modulate the Fast Inactivation Phase in Calcium Selective TRP Channels. Biophys J 2018. [DOI: 10.1016/j.bpj.2017.11.2660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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22
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Decher N, Ortiz-Bonnin B, Friedrich C, Schewe M, Kiper AK, Rinné S, Seemann G, Peyronnet R, Zumhagen S, Bustos D, Kockskämper J, Kohl P, Just S, González W, Baukrowitz T, Stallmeyer B, Schulze-Bahr E. Sodium permeable and "hypersensitive" TREK-1 channels cause ventricular tachycardia. EMBO Mol Med 2017; 9:403-414. [PMID: 28242754 PMCID: PMC5376757 DOI: 10.15252/emmm.201606690] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
In a patient with right ventricular outflow tract (RVOT) tachycardia, we identified a heterozygous point mutation in the selectivity filter of the stretch-activated K2P potassium channel TREK-1 (KCNK2 or K2P2.1). This mutation introduces abnormal sodium permeability to TREK-1. In addition, mutant channels exhibit a hypersensitivity to stretch-activation, suggesting that the selectivity filter is directly involved in stretch-induced activation and desensitization. Increased sodium permeability and stretch-sensitivity of mutant TREK-1 channels may trigger arrhythmias in areas of the heart with high physical strain such as the RVOT We present a pharmacological strategy to rescue the selectivity defect of the TREK-1 pore. Our findings provide important insights for future studies of K2P channel stretch-activation and the role of TREK-1 in mechano-electrical feedback in the heart.
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Affiliation(s)
- Niels Decher
- Institute of Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg, Marburg, Germany
| | - Beatriz Ortiz-Bonnin
- Institute of Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg, Marburg, Germany
| | - Corinna Friedrich
- Department of Cardiovascular Medicine, Institute for Genetics of Heart Diseases (IfGH), University Hospital Münster, Münster, Germany
| | - Marcus Schewe
- Institute of Physiology, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Aytug K Kiper
- Institute of Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg, Marburg, Germany
| | - Susanne Rinné
- Institute of Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg, Marburg, Germany
| | - Gunnar Seemann
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg - Bad Krozingen, Medical Center - University of Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Rémi Peyronnet
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg - Bad Krozingen, Medical Center - University of Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Sven Zumhagen
- Department of Cardiovascular Medicine, Institute for Genetics of Heart Diseases (IfGH), University Hospital Münster, Münster, Germany
| | - Daniel Bustos
- Center for Bioinformatics and Molecular Simulation, University of Talca, Talca, Chile
| | - Jens Kockskämper
- Institute of Pharmacology and Clinical Pharmacy, Biochemical and Pharmacological Center (BPC) Philipps-University of Marburg, Marburg, Germany
| | - Peter Kohl
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg - Bad Krozingen, Medical Center - University of Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Steffen Just
- Molecular Cardiology, University Hospital Ulm, Ulm, Germany
| | - Wendy González
- Center for Bioinformatics and Molecular Simulation, University of Talca, Talca, Chile
| | - Thomas Baukrowitz
- Institute of Physiology, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Birgit Stallmeyer
- Department of Cardiovascular Medicine, Institute for Genetics of Heart Diseases (IfGH), University Hospital Münster, Münster, Germany
| | - Eric Schulze-Bahr
- Department of Cardiovascular Medicine, Institute for Genetics of Heart Diseases (IfGH), University Hospital Münster, Münster, Germany
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23
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Schott S, Valdebenito B, Bustos D, Gomez-Porras JL, Sharma T, Dreyer I. Cooperation through Competition-Dynamics and Microeconomics of a Minimal Nutrient Trade System in Arbuscular Mycorrhizal Symbiosis. Front Plant Sci 2016; 7:912. [PMID: 27446142 PMCID: PMC4921476 DOI: 10.3389/fpls.2016.00912] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 06/09/2016] [Indexed: 05/17/2023]
Abstract
In arbuscular mycorrhizal (AM) symbiosis, fungi and plants exchange nutrients (sugars and phosphate, for instance) for reciprocal benefit. Until now it is not clear how this nutrient exchange system works. Here, we used computational cell biology to simulate the dynamics of a network of proton pumps and proton-coupled transporters that are upregulated during AM formation. We show that this minimal network is sufficient to describe accurately and realistically the nutrient trade system. By applying basic principles of microeconomics, we link the biophysics of transmembrane nutrient transport with the ecology of organismic interactions and straightforwardly explain macroscopic scenarios of the relations between plant and AM fungus. This computational cell biology study allows drawing far reaching hypotheses about the mechanism and the regulation of nutrient exchange and proposes that the "cooperation" between plant and fungus can be in fact the result of a competition between both for the same resources in the tiny periarbuscular space. The minimal model presented here may serve as benchmark to evaluate in future the performance of more complex models of AM nutrient exchange. As a first step toward this goal, we included SWEET sugar transporters in the model and show that their co-occurrence with proton-coupled sugar transporters results in a futile carbon cycle at the plant plasma membrane proposing that two different pathways for the same substrate should not be active at the same time.
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24
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Céccoli G, Bustos D, Ortega LI, Senn ME, Vegetti A, Taleisnik E. Plasticity in sunflower leaf and cell growth under high salinity. Plant Biol (Stuttg) 2015; 17:41-51. [PMID: 24942979 DOI: 10.1111/plb.12205] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Accepted: 04/09/2014] [Indexed: 05/21/2023]
Abstract
A group of sunflower lines that exhibit a range of leaf Na(+) concentrations under high salinity was used to explore whether the responses to the osmotic and ionic components of salinity can be distinguished in leaf expansion kinetics analysis. It was expected that at the initial stages of the salt treatment, leaf expansion kinetics changes would be dominated by responses to the osmotic component of salinity, and that later on, ion inclusion would impose further kinetics changes. It was also expected that differential leaf Na(+) accumulation would be reflected in specific changes in cell division and expansion rates. Plants of four sunflower lines were gradually treated with a relatively high (130 mm NaCl) salt treatment. Leaf expansion kinetics curves were compared in leaves that were formed before, during and after the initiation of the salt treatment. Leaf areas were smaller in salt-treated plants, but the analysis of growth curves did not reveal differences that could be attributed to differential Na(+) accumulation, since similar changes in leaf expansion kinetics were observed in lines with different magnitudes of salt accumulation. Nevertheless, in a high leaf Na(+) -including line, cell divisions were affected earlier, resulting in leaves with proportionally fewer cells than in a Na(+) -excluding line. A distinct change in leaf epidermal pavement shape caused by salinity is reported for the first time. Mature pavement cells in leaves of control plants exhibited typical lobed, jigsaw-puzzle shape, whereas in treated plants, they tended to retain closer-to-circular shapes and a lower number of lobes.
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Affiliation(s)
- G Céccoli
- Facultad de Ciencias Agrarias, Instituto de Agrobiotecnología del Litoral (CONICET-Universidad Nacional del Litoral), Esperanza, Argentina; CONICET, Consejo de Investigaciones Científicas y Técnicas de la República Argentina, Córdoba, Argentina
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25
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Begué C, Beratarrechea AG, Varela E, Piccioni HL, Rodota L, Castro ME, Koll MF, Bustos D, Dawidowski A, Langlois E, Marchetti M, De Paula JA. [Celiac disease: diagnosis prevalence in a community hospital]. Acta Gastroenterol Latinoam 2010; 40:317-322. [PMID: 21381406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
INTRODUCTION Celiac disease (CD) is a gluten-sensitive enteropathy characterized by a chronic injury of the small bowel, caused by gluten intolerance in genetically predisposed individuals. The different forms of presentation of CD resemble more a multisystem disorder than a primary gastrointestinal disease and it is frequently underdiagnosed. OBJECTIVE To determine the prevalence of CD diagnosis in the population of affiliates to the HMO of the Hospital Italiano de Buenos Aires. METHODS This is a cross sectional study, using secondary databases of diagnosis and laboratory from the electronic medical record (EMR) in a HMO population between 1998 and 2006. The criteria used to define a case was based on a diagnosis of CD in the EMR and/or a IgA antitransglutaminase antibodies value >15 AU/mL. RESULTS According to these criteria, 283 patients with CD were identified in 128,748 individuals of the HMO. The prevalence of CD was 0.22%. The mean age of this group was of 42.3 years, and 80.2% of them were female. CONCLUSIONS In a primary care HMO setting, using secondary databases from EMR we found 1 case of celiac disease every 470 affiliates, giving a prevalence of 0.22%. The rate between serological prevalence of CD and clinical diagnosis carried out in our center was near 3.3 to 1. Although this level of diagnosis could be considered relatively high, an important proportion of patients are left without diagnosis, considering the local estimated prevalence reported using serological tests. An increased level of awareness and clinical suspicion is needed at the primary care level.
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Affiliation(s)
- Carolina Begué
- Programas Médicos del Plan de Salud, Hospital Italiano, Ciudad Autónoma de Buenos Aires, Argentina.
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26
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Pavan J, Bustos D, Ferreyra L, Biganzoli P, Carricart S, Nates S. 35: Isotype immune response of IgG antibodies at the persistence and reactivation stages of human herpesvirus 6 infection. J Clin Virol 2006. [DOI: 10.1016/s1386-6532(06)70054-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Abstract
PROBLEM To determine the presence or absence of subclinical autoimmunity in Caucasian Argentine healthy women with first trimester recurrent pregnancy loss (RPL), the sera of 118 healthy women with a history of three or more consecutive abortions and 125 fertile control women without abortions and two children were analyzed for the presence of autoantibodies: immunoglobulin (Ig)G and IgM anticardiolipin, antinuclear (ANA), antismooth muscle (ASMA), antimitocondrial (AMA), antiliver-kidney-microsomal fraction (LKM), antigastric parietal cells (GPC), antineutrophil cytoplasmatic (ANCA) and antibodies antigliadin type IgA and IgG and IgA antitransglutaminase related with celiac disease (CD). METHOD OF STUDY ANA, ASMA, AMA, anti-LKM, antibodies to GPC and ANCA were determined by indirect immunofluorescence (IFI) and anticardiolipin, antigliadina and antitransglutaminase antibodies were measured by enzyme-linked immunosorbent assays (ELISA). RESULTS There was no significant difference between controls and patients with ANA, ASMA, AMA, LKM, ANCA and GPC. The prevalence of anticardiolipin antibodies in RPL was significantly higher than controls (P < 0,01) and the prevalence of positive antibodies for antigliadina type IgA and IgG and IgA antitransglutaminase in RPL was significantly higher than controls (P < 0.04). CONCLUSION We show that Caucasian Argentine women with RPL showed significantly higher incidence of anticardiolipin antibodies than normal controls and finally we recommended the screening of IgA and IgG antigliadina and IgA antitransglutaminase antibodies in pregnancy, because of the high prevalence of subclinical CD in RPL and the chance of reversibility through consumption of a gluten free diet.
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Affiliation(s)
- Daniel Bustos
- Central Laboratory, Diagnostic Department, Hospital Italiano de Buenos Aires, Gascón 450, Buenos Aires, Argentina.
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28
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Alessio LA, Carricart SE, Bustos D, Nates SV, Gendelman H, Pavan JV. Loss of maternally derived human herpesvirus-6 immunity and natural infection in Argentinian infants. Int J Infect Dis 2002; 5:202-4. [PMID: 11953217 DOI: 10.1016/s1201-9712(01)90071-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND Human herpesvirus-6 (HHV-6) infection is widespread throughout the world. No data are available in Argentina about the loss of maternally derived HHV-6 immunity and natural infection in infants. METHODS A population of 100 pregnant women and 407 children between 1 and 15 months of age were assayed by indirect immunofluorescence to detect and quantify specific IgG anti-human herpesvirus-6 (anti-HHV-6) antibodies in Córdoba City, Argentina. RESULTS There was no significant difference in the positive rate between infants aged 1 to 9 months (range, 43.6 35.5%) and pregnant women (37%). Seropositive ratio dropped in the 10-month group (23.33% seropositive) and rose sharply in the 11-month group (38.89%), 12-month (60.61%), and 13- to 15-month group (63.46%). The geometric mean titer (GMT) for infants in the 12 to 15 months age group (23.4 41.64) was significantly higher than the GMT for infants 10 months of age (11.04) (P < 0.05 with the Tukey-HSD test). CONCLUSIONS This study shows a significant association between loss of passive HHV-6 antibody and age among infants. The results support evidence that HHV-6 enters the susceptible population at 11 months, leading to a high prevalence of antibodies in children between 13 and 15 months of age.
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Affiliation(s)
- L A Alessio
- School of Medical Sciences, National University of Córdoba, Argentina
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29
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Argibay PF, Di Noia JM, Hidalgo A, Mocetti E, Barbich M, Lorenti AS, Bustos D, Tambutti M, Hyon SH, Frasch ACC, Sánchez DO. Trypanosoma cruzi surface mucin TcMuc-e2 expressed on higher eukaryotic cells induces human T cell anergy, which is reversible. Glycobiology 2002; 12:25-32. [PMID: 11825884 DOI: 10.1093/glycob/12.1.25] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Chagas' disease is a chronic, debilitating, multisystemic disorder that affects millions of people in Latin America. The protozoan parasite Trypanosoma cruzi, the etiological agent of Chagas' disease, has a large number of O-glycosylated Thr/Ser/Pro-rich mucin molecules on its surface (TcMuc). These mucins are the main acceptors of sialic acid and have been suggested to play a role on various host-parasite interactions, such as adhesion to macrophages, protection from complement lysis, and immunomodulation of the immune response mounted by the host. To observe the immunologic effect obtained by the heterologous expression of a TcMuc gene in higher eukaryotic cells exposed to xenogeneic lymphocytes, we developed a strategy based on the transfection of a known T. cruzi mucin gene (TcMuc-e2) into Vero cells. In contrast to the brisk proliferation and activation of human lymphocytes observed at 3, 4, and 5 days induced by normal Vero cells, neither proliferation nor significant activation of human lymphocytes was observed with TcMuc-e2-transfected Vero cells. This TcMuc-e2 mucin-induced suppression of T cell response can be reversed by the addition of exogenous IL-2. In addition it was demonstrated that the immunosuppressive reaction was not related to the induction of an important degree of apoptosis in human lymphocytes. Posttranslational modification are required for the inhibitory effect that TcMuc-e2 exerts when transfected to Vero cells. O-glycosylation and sialylation are required to obtain the immunomodulatory effect as assessed by O-sialoglycoprotease and neuraminidase treatments. These results are consistent with other studies showing that surface glycoconjugates from T. cruzi and mammalian cells can induce an inhibition of the immune response.
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Affiliation(s)
- Pablo F Argibay
- Instituto de Ciencias Básicas y Medicina Experimental, Hospital Italiano de Buenos Aires, Gascón 450, (1181) Buenos Aires, Argentina
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Perrenoud J, Bustos D, Herrmann F, Michel JP. Patent foramen ovale and survival in old age. Age Ageing 2000; 29:460-1. [PMID: 11108425 DOI: 10.1093/ageing/29.5.460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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31
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Bustos D, Greco G, Yapur V, Facente A, Di Carlo M, Bustos F, Dapia L, Ascione A, Negri G. Quantification of fecal neutrophils by MPO determination (myeloperoxidase) in patients with invasive diarrhea. Cuantificación de neutrofilos fecales mediante la determinación de MPO (Mieloperoxidasa) en pacientes con diarrea invasiva. Acta Gastroenterol Latinoam 2000; 30:85-7. [PMID: 10925724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Myeloperoxidase (MPO), a specific polymorphonuclear leukocyte enzyme, has been used previously to quantify the number of neutrophils in tissue. MPO activity was found to be linearly related to the number of neutrophil cells. In an attempt to use this method in leukocytes measuring in stool, fecal MPO was solubilized with hexadecyltrimethylammonium bromide and the MPO activity was measured by a dianisidine-H2O2 assay. Stools from 10 normal subjects and 39 patients with diarrhea produced by enteropathogenic bacteria were examined for leukocytes by MPO activity as well as microscopically using methylene blue stain, MPO activity was positive in 36 patients (92%) and leukocytes were present by microscopic observation in 30 (77%). Fecal leukocytes were not found in healthy controls and the MPO activity was undectable. Stool MPO activity had a range of from 1.6 to 2,830.0 x 10(3) UMPO per gram of feces (median 460.0). The number of neutrophils obtained through MPO activity had a range of 6.0 to 13,216.0/ mm3 (median 1,261.0). Fecal MPO activity is a simple biochemical assay for the detection and quantification of fecal leukocytes.
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Ferraris JR, Tambutti ML, Redal MA, Bustos D, Ramirez JA, Prigoshin N. Conversion from azathioprine [correction of azathioprina] to mycophenolate mofetil in pediatric renal transplant recipients with chronic rejection. Transplantation 2000; 70:297-301. [PMID: 10933152 DOI: 10.1097/00007890-200007270-00010] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Chronic rejection is the leading cause of graft failure. Both nonimmunological and immunological mechanisms contribute to this pathology. METHODS We studied changes in kidney function, mixed lymphocyte culture, cell-mediated lympholysis, serum HLA class I antigens, cytotoxic antibodies, and lymphocyte population before and after 6 months of follow-up in 22 pediatric renal transplanted patients. The immunosuppressive protocol used was: cyclosporine, azathioprine, and corticosteroids. Eight patients demonstrated chronic graft rejection (by biopsy), group I; and eight patients had no clinical evidence of chronic and/or acute rejection, group II. Substitution of mycophenolate mofetil (MMF) (600 mg/m2 bid for azathioprine was done in patients of groups I and II. Another six patients with chronic rejection, did not receive MMF, group III. RESULTS Creatinine clearance increased in group I (44+/-5 vs. 51.1+/- ml/min/1.73 m2, P<0.03) but it decreased in group III (30+/-3 vs. 25+/-2, P<0.01). Urinary protein excretion decreased only in group I (0.3+/-0.03 to 0.06+/-0.03 g/24 hr, P<0.03). During MMF therapy antidonor mixed lymphocyte culture decreased 62 and 70% (P<0.05) in group I and II. Cell-mediated lympholysis against lymphocyte of the donor decreased 65% (P<0.05) in group I. Cell-mediated lympholysis toward control cells decreased 54% (P<0.01) in group II. Serum HLA class I antigens, only decreased from 0.7+/-0.1 to 0.5+/-0.1 microl/ml, P<0.05, in group I. CD19+ decreased from 7.9+/-1.1 to 5.6+/-0.8%, P<0.05, and 7.8+/-1.2 to 5.5+/-0.9%, P<0.05, in groups I and II, respectively. CD16+ increased from 5.7+/-1.1 to 8.6+/-1.3 (P<0.05) only in group I. CONCLUSIONS Our data suggest that substituting MMF for azathioprine therapy leads to an improvement in the immunosuppression and renal function in children with on-going chronic rejection.
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Affiliation(s)
- J R Ferraris
- Department of Pediatrics, Hospital Italiano de Buenos Aires, Argentina
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Tapia A, Egly Feresin G, Bustos D, Astudillo L, Theoduloz C, Schmeda-Hirschmann G. Biologically active alkaloids and a free radical scavenger from Prosopis species. J Ethnopharmacol 2000; 71:241-246. [PMID: 10904169 DOI: 10.1016/s0378-8741(00)00171-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The biological activity of extracts from the aerial parts of five Argentinian Prosopis species and the exudate of P. flexuosa were assessed for DNA binding, beta-glucosidase inhibition and free radical scavenging effect using the DPPH decoloration assay. DNA binding effect was found mainly in the basic fraction. The alkaloids tryptamine as well as piperidine and phenethylamine derivatives were isolated from the basic extracts. At 0.50 mg/ml, DNA binding activities ranged from 28% for tryptamine to 0-27% for the phenethylamine and 47-54% for the piperidine derivatives. Tryptamine and 2-beta-methyl-3-beta-hydroxy-6-beta-piperidinedodecanol showed a moderate inhibition (27-32%) of the enzyme beta-glucosidase at 100 microg/ml. The exudate of P. flexuosa displayed a strong free radical scavenger effect in the DPPH decoloration assay. The main active constituent was identified as catechin.
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Affiliation(s)
- A Tapia
- Instituto de Ciencias Básicas, Universidad Nacional de San Juan, Avda. Ignacio de La Roza 230 Oeste, 5400, San Juan, Argentina
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Bustos D, Hutchinson DBA. Reply. J Infect Dis 2000. [DOI: 10.1086/315218-a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Bustos D, Hutchinson DB. Reply. J Infect Dis 2000; 181:405. [PMID: 10608799 DOI: 10.1086/315218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Affiliation(s)
- D Bustos
- HIV/OI Clinical Development, Glaxo Wellcome, Inc., 5 Moore Dr., Research Triangle Park, NC 27709, USA
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Bustos D, Negri G, De Paula JA, Di Carlo M, Yapur V, Facente A, De Paula A. Colonic proteinases: increased activity in patients with ulcerative colitis. Medicina (B Aires) 1998; 58:262-4. [PMID: 9713093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
In order to study the colonic intraluminal proteinase-antiproteinase imbalance under inflammatory conditions, we determined proteolytic activity (PA), alpha-1-antitrypsin and the activities of trypsin, chymotrypsin and neutrophil elastase in feces from patients with ulcerative colitis (UC) comparing the results with a control group. A fecal sample was obtained from each 25 patients with ulcerative colitis and 10 control subjects were studied. The severity of the disease was assessed by the Truelove index. Proteolytic activity was measured using azocasein as proteolytic substrate. The fecal concentration of alpha-1-antitrypsin was measured by radial immunodiffusion and the activities of the enzymes were measured using specific substrates. We found an increase in fecal PA, alpha-1-antitrypsin and neutrophil elastase in patients with UC and the correlation between the severity of the disease and the PA was statistically significant (r = 0.62, P < 0.05). We conclude that elevated colonic proteinase activity could contribute to the pathophysiology of ulcerative colitis.
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Affiliation(s)
- D Bustos
- Laboratorio de Gastroenterología, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Hospital Italiano
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37
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Vilacosta I, Bustos D, Cigüenza R, Graupner C, Stoermann W, Pérez MA, Sánchez-Harguindey L. Primary mycotic aneurysm of the ascending aorta diagnosed by transesophageal echocardiography. J Am Soc Echocardiogr 1998; 11:216-8. [PMID: 9517563 DOI: 10.1016/s0894-7317(98)70081-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Primary mycotic aneurysms are rare, and they can be difficult to diagnose before rupture. Early diagnosis is the cornerstone to effective management. Preoperative diagnosis has traditionally involved angiography and computed tomography. We report a case of Staphylococcus aureus aortitis with an aortic wall abscess and posterior pseudoaneurysm formation involving the ascending aorta in which transesophageal echocardiography was fundamental in diagnosis and patient management.
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Affiliation(s)
- I Vilacosta
- Department of Cardiology, Hospital Universitario de San Carlos, Madrid, Spain
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38
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Gay F, Bustos D, Traore B, Jardinel C, Southammavong M, Ciceron L, Danis MM. In vitro response of Plasmodium falciparum to atovaquone and correlation with other antimalarials: comparison between African and Asian strains. Am J Trop Med Hyg 1997; 56:315-7. [PMID: 9129535 DOI: 10.4269/ajtmh.1997.56.315] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Atovaquone (dihydroxynaphthoquinone 566C80) is a broad-spectrum antiprotozoal compound demonstrating potent antimalarial activity against multidrug-resistant malaria. We present the results of in vitro drug sensitivity tests of 142 Plasmodium falciparum isolates, 108 from 14 countries of West and Central Africa, 32 from the Philippines, and one each from Laos and Myanmar. These were tested in vitro against nine drugs: the classic antimalarials chloroquine, quinine, mefloquine and halofantrine, the four qinghaosu derivatives, artemisinin, artemether, artesunate, and arteether, and the new compound atovaquone. Results showed the Asian strains have a higher median 50% inhibitory concentration (IC50) to almost all drugs compared with those from Africa. This was significantly different for chloroquine, halofantrine, and artemisinin. We used three different approaches to estimate the threshold for resistance of atovaquone to be approximately 5-7 nmol/L. The global median of 96 pooled strains is 1.4 nmol/L and the 90th percentile is 5.5 nmol/L for atovaquone. There were no correlations of atovaquone with the eight other antimalarials among African strains, but significant correlations, except for halofantrine, were observed among Asian strains. The absence of a correlation between atovaquone and the other available drugs indicates the potential of atovaquone as an alternative antimalarial in Africa. The correlation observed among Asian strains, however, suggests that atovaquone has to be used cautiously in Asia. Nevertheless, the association with proguanil in recently concluded clinical trials in Europe, South America, Asia, and Africa has demonstrated its antimalarial efficacy.
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Affiliation(s)
- F Gay
- Departement de Medecine Tropicale, Groupe Hospitalier Pitie-Salpetriere, Paris, France
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Caldarini MI, Pons S, D'Agostino D, DePaula JA, Greco G, Negri G, Ascione A, Bustos D. Abnormal fecal flora in a patient with short bowel syndrome. An in vitro study on effect of pH on D-lactic acid production. Dig Dis Sci 1996; 41:1649-52. [PMID: 8769294 DOI: 10.1007/bf02087915] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
D-Lactic acidosis associated with encephalopathy is a clinical condition that occurs in patients with short bowel syndrome. We studied the fecal flora and the composition of fecal water of a child who developed this unusual disorder. Bacteriological studies showed that the patient's stool contained a marked predominance of gram-positive anaerobes. Two strains were identified, Lactobacillus plantarum and Lactobacillus salivarius, as the main bacteria isolated. Fecal water showed pH 4.8 and total lactic acid (sum of L- and D-lactic acids) was the principal organic anion found in the feces. We also incubated the patient's stool in a continuous culture with a view to determining the effect of the pH on the production of volatile fatty acids (VFA) and L- and D-lactic acids. The culture was maintained at pH 5.0, 5.5, 6.0, and 6.5 for four consecutive periods of four days each. We then studied the culture for a further four days at pH 5.0 once again. This study showed that with the progressive rise of the pH from 5.0 to 6.5 L- and D-lactic acids decreased and VFA production increased. D-Lactic acid formation was inhibited at pH 6.5, but when the culture was returned to pH 5.0, it increased to a high level again. These results suggest that the pH plays an important role in the ecological changes in the colonic bacteria that result in D-lactic acid production.
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Affiliation(s)
- M I Caldarini
- Departamento de Bioquímica Clínica. Facultad de Farmacia y Bioquímica, Buenos Aires, Argentina
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Abstract
Growing morbidity and mortality rates call for research towards more effective methods of preventing asthma. During the last decade several groups have reported the results of natural history and asthma prevention studies. However, the attempt to prevent development of asthma in genetically predisposed children, has not resulted in a generally accepted management scheme. The aim of this study was to evaluate the effectiveness of ketotifen in preventing the onset of asthma in infants considered to be at high risk of developing the disease, but who had no history of respiratory obstruction. These children have been described as preasthmatic. In this double-blind, placebo-controlled, parallel study, 100 infants with a family history of major allergy and elevated serum IgE levels, but with no history of bronchial obstruction, were treated with either ketotifen (n = 50) or placebo (n = 50) over a 3-year period. There were no statistically significant differences between the two groups with regard to age, sex, degree of hereditary allergy, levels of serum IgE upon joining the study, and family smoking habits. At the end of 3 years, only four of the 45 infants who had received ketotifen had developed asthma (9%). Of the 40 children given placebo, 14 had developed asthma (35%) (P = 0.003). These results suggest that ketotifen is effective in preventing the onset of asthma in preasthmatic children.
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Affiliation(s)
- G J Bustos
- Paediatrics Department, Catholic University of Cordoba, Argentina
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Abstract
In patients with short bowel syndrome (SBS), the carbohydrate overload to the colon may disturb the normal pattern of colonic fermentation with production of D-lactic acid and subsequent development of a metabolic D-lactic acidosis. We measured D-lactic acid in blood, urine, and feces, as well as the composition of fecal water and fecal reducing substances from 11 patients with SBS, comparing the results with those from normal subjects. The fecal water from patients with SBS was characterized by low pH, potassium, and volatile fatty acids, high osmotic gap, and high concentration of L- and D-lactic acid. Five of 11 had abnormal amounts of fecal reducing substances. Fecal D-lactic acid was increased in nine of 11 patients. However, none of these patients showed D-lactic acid in urine, and only one had a very low concentration in plasma. These results show that D-lactic acid was overproduced in the colon of most of the patients with SBS. However, other factors such as absorption or impaired D-lactic acid metabolism may be necessary for a plasmatic increase of D-lactic acid.
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Affiliation(s)
- D Bustos
- Instituto de Gastroenterologia Dr. Jorge Perez Companc, Buenos Aires, Argentina
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Bustos D, Tiscornia O, Caldarini MI, Negri G, Pons S, Ogawa K, De Paula JA. Colonic proteolysis following pancreatic duct ligation in the rat. Int J Pancreatol 1994; 16:45-9. [PMID: 7806912 DOI: 10.1007/bf02925609] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Luminal proteolytic activity (PA) of different colonic segments was ascertained in animals subjected to pancreatic duct ligation (PDL) and in control rats. The PDL rats revealed a significant PA reduction in the cecum, proximal colon (P < 0.01), and distal colon (P < 0.005). Proteolytic activity, trypsin, and chymotrypsin activity in control rats diminished progressively from the cecum to the distal colon. Conversely in PDL rats, we found maximal PA in distal colon. The conclusion is drawn that a significant proportion of colonic proteolytic activity can be attributed to pancreatic proteases with a maximal contribution at cecum level.
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Affiliation(s)
- D Bustos
- Instituto de Gastroenterologia, Dr. Jorge Perez Companc, Buenos Aires, Argentina
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Carvajal N, Vega E, Erices A, Bustos D, Torres C. Lactate dehydrogenase, alanopine dehydrogenase and octopine dehydrogenase from the heart of Concholepas concholepas (Gastropoda: Muricidae). ACTA ACUST UNITED AC 1994. [DOI: 10.1016/0305-0491(94)90108-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Cheng Q, Stowers A, Huang TY, Bustos D, Huang YM, Rzepczyk C, Saul A. Polymorphism in Plasmodium vivax MSA1 gene--the result of intragenic recombinations? Parasitology 1993; 106 ( Pt 4):335-45. [PMID: 8100358 DOI: 10.1017/s003118200006707x] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The diversity in a 925 bp portion of the Plasmodium vivax MSA1 gene in isolates from the Philippines, China, the Solomon Islands and Papua New Guinea was investigated. A total of 74 base pair changes was found in the amplified fragment from 18 isolates. Most of these changes were single or double base pair substitutions. In several regions, these point changes were tightly linked with one set always present or always absent in the different isolates. Seven such blocks were identified. These blocks were present in different combinations in the different isolates indicating that extensive intragenic recombination has occurred.
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Affiliation(s)
- Q Cheng
- Queensland Institute of Medical Research, Brisbane, Australia
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Bustos D, Perrenoud JJ, Michel JP, Grab B, McGee W. [Postmortem diagnosis of cardiac amyloidosis in the aged. Anatomoclinical correlation]. Arch Mal Coeur Vaiss 1993; 86:315-9. [PMID: 8215766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The absence of specific clinical signs makes the diagnosis of cardiac amyloidosis difficult. Moreover, it is established that this condition, the prevalence of which increases with age, aggravates the prognosis of cardiac failure. The present study was undertaken to identify the clinical or paraclinical signs enabling more accurate diagnosis of this disease. Analysis of 2589 autopsy reports from the University Institutes of Geriatrics of Geneva between January 1972 and January 1990 recensed 58 cases of microscopic cardiac amyloidosis, but this diagnosis was not made in any of these patients before death. Of the potential indicators, the good specificity but poor sensitivity of atrial fibrillation and low voltage electrocardiogram was confirmed. On the other hand, the author's research found the association of radiological cardiomegaly and a raised erythrocyte sedimentation rate in nearly 70% of cases of cardiac amyloidosis with a false positive rate of only 10% in a control group.
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Affiliation(s)
- D Bustos
- Institutions universitaires de gériatrie, Suisse
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Bustos D, Negri G, Bandi JC, Caldarini MI, Ogawa K, Pons S, De Paula JA. Effects of right hemicolectomy on fecal nitrogen excretion in rats. Ann Nutr Metab 1993; 37:85-9. [PMID: 8517638 DOI: 10.1159/000177754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The influence of right hemicolectomy (RH) on fecal nitrogen excretion was determined with selected protein levels up to 25%. The endogenous fecal N was determined by extrapolating protein intake to zero. Fecal N was higher in RH than in control rats at all protein levels used. However, the slope of regression curves describing fecal nitrogen excretion was greater for RH compared with the control group. The endogenous fecal nitrogen was not significantly different between the two groups of rats. The feces from rats fed with 25% of protein were partitioned into individual fractions by physical separation and a study was made of the distribution of nitrogen in the bacterial, soluble and fiber fractions of the stool. RH decreased the N excreted in the bacterial fraction by 33% (from 1.71 +/- 0.32 to 1.15 +/- 0.18 mmol/day) and increased the N excreted in the soluble fraction by 280% (from 1.60 +/- 0.30 to 6.08 +/- 1.16 mmol/day). These results show that the RH increased the fecal N excretion and that this N is mainly in the soluble fraction.
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Affiliation(s)
- D Bustos
- Instituto de Gastroenterologia Jorge Perez Companc, Seccion Metabolismo Bacteriano, Buenos Aires, Argentina
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Ben RA, Dapia L, Bustos D. Fecal chymotrypsin in infants fed different diets. J Pediatr Gastroenterol Nutr 1993; 16:104. [PMID: 8433229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
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Bustos D, De Paula JA, Tagliabue E, Bandi JC, Fernandez LB. Effects of right hemicolectomy on nitrogen balance in the rat. Ann Nutr Metab 1992; 36:175-80. [PMID: 1530287 DOI: 10.1159/000177714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Rats with right hemicolectomy were divided into two groups. One group was free-fed (RHFF), the other group pair-fed (RHPF) and both were compared with a group of control animals. The nitrogen balance (NB) was studied for 5 days at 2 and 14 weeks after surgery. The two groups of rats with right hemicolectomy excreted significantly more fecal nitrogen than the control group (p less than 0.01) during the two periods of study. At 2 weeks the RHFF group increased N intake so that their NB was similar to that of the control group. In the same period the nitrogen lost in urine and the NB were reduced in the RHPF rats (p less than 0.01). At 14 weeks the results were similar to those for 2 weeks although the increase in food intake for RHFF and the decrease in NB for RHPF were not statistically significant. The rats with right hemicolectomy showed a decreased gain in body weight. This decrease was more pronounced in the RHPF group. The nitrogen content of the carcass and liver was significantly reduced in the RHPF group 4 months after surgery. It is concluded that the rats with right hemicolectomy were characterized by an increment in the nitrogen lost in feces, and when they were only allowed the same intake of food as the control group, the animals showed marked abnormalities in growth and in the nitrogen content of the organism.
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Affiliation(s)
- D Bustos
- Instituto de Gastroenterologia, Dr. Jorge Perez Companc, Buenos Aires, Argentina
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Affiliation(s)
- J Babinet
- Centre de Transfusion Sanguine, Groupe Hospitalier Pitié-Salpêtrière, Paris, France
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50
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