Estudios computacionales del receptor Toll-like 4

Tesis de la Universidad Complutense de Madrid, Facultad de Farmacia, Departamento de Química Orgánica y Farmacéutica, leída el 11/10/2017This Thesis is focused on the molecular modeling and computational study of the molecular recognition processes involving Pattern Recognition Receptors (PRRs), in particular, Toll-like receptors (TLRs). TLRs are the main actors in innate immunity and are specialized in the recognition of pathogen associated molecular patterns (PAMPs). In particular, TLR4 is located in the plasma membrane where, together with the MD-2 protein, it binds to lipopolysaccharides, membrane constituents of Gramnegative bacteria, forming a heterodimeric complex. TLR4 agonists can be used as adjuvants in vaccine development and in cancer immunotherapy. TLR4 antagonists have also been studied for their promising application in septic shock, chronic inflammation and autoimmunity. However, the mechanism at atomic level for such activation/inactivation process remains unknown. Our research has been focused on the study of the mechanism of the TLR4/MD-2 system by means of computational approaches. In order to carry out our research objectives, we use a combination of several computational tools: geometry optimization, charges calculations, docking, virtual screening, and molecular dynamics simulations of protein complexes and membranes. The main objective of this Thesis is to elucidate the ligand-protein interactions of TLR4 at atomic detail through computational techniques. Computational methodologies will be applied to the study of the molecular mechanisms involved in the TLRs functionality, and in the recognition of PAMPs. Ligand-protein docking and virtual screening will be used as a source of new compounds able to modulate the TLRs behavior with possible therapeutic applications, and also as biological probes...En esta Tesis Doctoral se han empleado técnicas de modelado molecular y se ha llevado a cabo el estudio computacional de los procesos de reconocimiento molecular que implican Receptores de Reconocimiento de Patrones (PRRs), en particular, los receptores Toll-like (TLRs). Los TLRs son los principales actores en la inmunidad innata y se especializan en el reconocimiento de patrones moleculares asociados a patógenos (PAMPs). En particular, el receptor TLR4 se localiza en la membrana plasmática donde, junto con la proteína MD-2, se une a lipopolisacáridos, constituyentes de membrana de bacterias Gram-negativas, que forman un complejo heterodimérico. Los agonistas de TLR4 pueden ser útiles como coadyuvantes en el desarrollo de la vacuna y en la inmunoterapia contra el cáncer. Los antagonistas de TLR4 también han sido estudiados por su prometedora aplicación en choque séptico, inflamación crónica y autoinmunidad. Sin embargo, el mecanismo a nivel atómico para tal proceso de activación/inactivación sigue siendo desconocido. Nuestra investigación se ha centrado en el estudio del mecanismo del sistema TLR4/MD-2 mediante métodos computacionales. Con el fin de llevar a cabo nuestros objetivos de investigación, hemos utilizado una combinación de varias herramientas computacionales: optimización de la geometría, cálculos de carga, docking, cribado virtual y simulaciones de dinámica molecular de complejos y membranas de proteínas. El objetivo principal de esta Tesis es elucidar las interacciones ligando-proteína del receptor TLR4 a nivel atómico a través de técnicas computacionales. Metodologías computacionales se aplicarán para el estudio de los mecanismos moleculares involucrados en la funcionalidad de los receptores Toll-like, y en el reconocimiento de los PAMPs. Técnicas de acoplamiento ligando-proteína y cribado virtual serán utilizadas, dando lugar a una fuente de nuevos compuestos capaces de modular el comportamiento de los TLRs con posibles aplicaciones terapéuticas, y también como sondas biológicas...Depto. de Química en Ciencias FarmacéuticasFac. de FarmaciaTRUEunpu

Erosion of universal health coverage and trend in the frequency of physician consultations in Spain

Background: We studied the frequency of physician visits in the native and immigrant populations in Spain before and after implementation of a governmental measure to restrict the use of public healthcare services by undocumented immigrants beginning in 2012. Methods: Data were taken from the 2009 and 2014 European Health Surveys carried out in Spain. We investigated any physician consultation in the last 4 weeks before the interview, as well as visits to a family physician, public specialist physician and private specialist physician. We estimated the frequency of visits in 2009 and in 2014 in the native and immigrant populations and the difference in the frequency between the two populations, by calculating the percentage ratio estimated by binomial regression and adjusted for different confounders that are indicators of the need for assistance. Results: The percentage of persons who consulted any physician in 2009 and 2014 was 31.7 and 32.9% in the native population, and 25.6 and 30.1% in the immigrant population, respectively. In the immigrant population, the frequency of visits to the general practitioner and public specialist physician increased, whereas in the native population only public specialist physician visits increased. The frequency of private specialist visits remained stable in both populations. After adjusting for the indicators of need for healthcare, no significant differences between the immigrant and native populations were seen in the frequency of visits, except for private specialist consultations, which were less frequent among immigrants. Conclusion: The restriction of universal healthcare coverage in Spain did not reduce the frequency of physician visits between 2009 and 2014, as the frequency of these consultations was seen to increase in both the native and immigrant populations.This study was supported by a grant from the “Plan Estatal de I + D, Ministry of Science, Innovation and Universities of Spain (no. CSO2017–83180-P)

Rural–urban disparities in the reduction of avoidable mortality and mortality from all other causes of death in Spain, 2003–2019

Aim This study aims to evaluate the trend of avoidable mortality and of mortality from all other causes of death in urban and rural areas in Spain, throughout the first 2 decades of the twenty-first century. Methods Data deaths and population by age and sex, according to the area of residence, were obtained from the National Institute of Statistics. Avoidable mortality refers to premature deaths (≤ 75 years old) for which there is reasonable scientific consensus that they should not occur in the presence of timely health care. In large urban, small urban, and rural areas, annual age-standardized mortality rates from avoidable causes and from all other causes of death were calculated from 2003 to 2019. The annual percentage change (APC) in the mortality rate in each area was estimated using linear regression models and taking age-standardized mortality rates as dependent variable. Results Mortality rates decreased between the beginning and the end of the period analysed. Large urban areas and rural areas showed the largest and smallest reduction in mortality rate respectively. The APC in avoidable mortality was −3.5% in men and −3.0% in women in large urban areas, and −2.7% in men and −2.6% in women in rural areas. The APC in the mortality rate from all other causes of death was −2.4% in men and −1.2% in women in large urban areas, and −1.4% in men and −1.0% in women in rural areas. Conclusion In Spain, avoidable mortality and mortality from other causes of death in rural and urban areas show similar trends, which suggests the presence of a common factor responsible for such findings.Open Access funding provided by Universidad Pública de Navarra. This study was supported by the Universidad Complutense de Madrid (grant No UCM 2022-920743)

Small Molecules as Toll-like Receptor 4 Modulators Drug and In-House Computational Repurposing

The innate immunity toll-like receptor 4 (TLR4) system is a receptor of paramount importance as a therapeutic target. Virtual screening following a “computer-aided drug repurposing” approach was applied to the discovery of novel TLR4 modulators with a non-lipopolysaccharide-like structure. We screened almost 29,000 approved drugs and drug-like molecules from commercial, public, and in-house academia chemical libraries and, after biological assays, identified several compounds with TLR4 antagonist activity. Our computational protocol showed to be a robust approach for the identification of hits with drug-like scaffolds as possible inhibitors of the TLR4 innate immune pathways. Our collaborative work broadens the chemical diversity for inspiration of new classes of TLR4 modulators.This work was financially supported by the Spanish Ministry for Science and Innovation (grants CTQ2014-57141-R, CTQ2017-88353-R, and PID2020-113588RB-I00 for S.M.S.; grants BES-2012-053653 for L.P.R., BES-2015-071588 for J.G.C. and PID2021-124983OB-I00 for J.C.M.), the Spanish Ministry of Economy and Competitiveness and the European Regional Development Fund (MINECO/FEDER; SAF2016-75988-R), and the Community of Madrid (S-2010/BMD-2332) for M.F

Antagonistic pleiotropy in the bifunctional surface protein FadL (OmpP1) during adaptation of Haemophilus influenzae to chronic lung infection associated with Chronic Obstructive Pulmonary Disease

Tracking bacterial evolution during chronic infection provides insights into how host selection pressures shape bacterial genomes. The human-restricted opportunistic pathogen nontypeable Haemophilus influenzae (NTHi) infects the lower airways of patients suffering chronic obstructive pulmonary disease (COPD) and contributes to disease progression. To identify bacterial genetic variation associated with bacterial adaptation to the COPD lung, we sequenced the genomes of 92 isolates collected from the sputum of 13 COPD patients over 1 to 9years. Individuals were colonized by distinct clonal types (CTs) over time, but the same CT was often reisolated at a later time or found in different patients. Although genomes from the same CT were nearly identical, intra-CT variation due to mutation and recombination occurred. Recurrent mutations in several genes were likely involved in COPD lung adaptation. Notably, nearly a third of CTs were polymorphic for null alleles of ompP1 (also called fadL), which encodes a bifunctional membrane protein that both binds the human carcinoembryonic antigen-related cell adhesion molecule 1 (hCEACAM1) receptor and imports long-chain fatty acids (LCFAs). Our computational studies provide plausible three-dimensional models for FadL's interaction with hCEACAM1 and LCFA binding. We show that recurrent fadL mutations are likely a case of antagonistic pleiotropy, since loss of FadL reduces NTHi's ability to infect epithelia but also increases its resistance to bactericidal LCFAs enriched within the COPD lung. Supporting this interpretation, truncated fadL alleles are common in publicly available NTHi genomes isolated from the lower airway tract but rare in others. These results shed light on molecular mechanisms of bacterial pathoadaptation and guide future research toward developing novel COPD therapeutics.IMPORTANCE Nontypeable Haemophilus influenzae is an important pathogen in patients with chronic obstructive pulmonary disease (COPD). To elucidate the bacterial pathways undergoing in vivo evolutionary adaptation, we compared bacterial genomes collected over time from 13 COPD patients and identified recurrent genetic changes arising in independent bacterial lineages colonizing different patients. Besides finding changes in phase-variable genes, we found recurrent loss-of-function mutations in the ompP1 (fadL) gene. We show that loss of OmpP1/FadL function reduces this bacterium's ability to infect cells via the hCEACAM1 epithelial receptor but also increases its resistance to bactericidal fatty acids enriched within the COPD lung, suggesting a case of antagonistic pleiotropy that restricts DeltafadL strains' niche. These results show how H. influenzae adapts to host-generated inflammatory mediators in the COPD airways

Discourse Analysis and Terminology in Languages for Specific Purposes

Aquest importantíssim recull conté estudis i reflexions sobre temes rellevants en la recerca sobre LSP: anglès mèdic, el llenguatge de la publicitat i periodístic, telecomunicacions i terminologia informàtica, llenguatge comercial i jurídic... Malgrat que gran part dels treballs aplegats es refereixen a l'anglès, també hi ha que tracten l'alemany, francès i altres llengües. Conté textos en anglès, francés, portuguès i castellà

Virtual Screening Approaches towards the Discovery of Toll-Like Receptor Modulators

This review aims to summarize the latest efforts performed in the search for novel chemical entities such as Toll-like receptor (TLR) modulators by means of virtual screening techniques. This is an emergent research field with only very recent (and successful) contributions. Identification of drug-like molecules with potential therapeutic applications for the treatment of a variety of TLR-regulated diseases has attracted considerable interest due to the clinical potential. Additionally, the virtual screening databases and computational tools employed have been overviewed in a descriptive way, widening the scope for researchers interested in the field

Mortality by cause of death and risk behaviors in farmers versus non-farmers: the importance of avoiding the healthy worker effect

Objectives: To compare mortality by cancer sites and by other specific causes of death, and the prevalence of risk behaviors in farmers and non-farmers in Spain. Methods: Mortality by cause of death was calculated based on a longitudinal study with 10-years follow-up of 9.5 million men and 6 million women aged 20–64 years who were employed in 2001. The prevalence of risk behaviors was calculated from the 2001 National Health Survey in the 6464 employed men and 5573 employed women aged 20–64. The study subjects were grouped as farmers and non-farmers. For each cause of death, we estimated the ratio of age-standardized mortality rates, and for each risk behavior we estimated the age-standardized prevalence ratio in farmers versus non-farmers. Results: In men, the mortality rate for most cancer sites did not differ significantly between farmers and non-farmers, except for cancers of the lip, oral cavity, stomach, larynx and skin epidermoid carcinoma—which was higher in farmers—and cancers of the liver, pancreas and mesothelioma—which was lower in farmers. In contrast, farmers had a higher rate of mortality from most other diseases and from external causes of death. In women, farmers showed lower mortality from lung cancer, breast cancer and chronic lower respiratory disease, and higher mortality from external causes. The prevalence of smoking, excessive alcohol consumption, physical inactivity and obesity was higher in farmers than in non-farmers, except smoking and excessive alcohol consumption in women where prevalence was lower in farmers. Conclusions: Findings are different from those found in other studies. In men, greater exposure to the sun and the higher prevalence of risk behaviors in farmers could explain their excess mortality from some cancer sites and the other causes of death. However, other factors may be behind this excess risk of mortality from these causes, given that farmers did not show higher mortality from some cancers related to smoking. In women, no differences were observed in mortality rate for majority of causes of death between farmers and non-farmers