Person: Díez Martín, Amalia
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First Name
Amalia
Last Name
Díez Martín
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Veterinaria
Department
Bioquímica y Biología Molecular
Area
Bioquímica y Biología Molecular
Identifiers
19 results
Search Results
Now showing 1 - 10 of 19
Item Microscopic and submicroscopic infection by Plasmodium falciparum: Immunoglobulin M and A profiles as markers of intensity and exposure(Frontiers in Cellular and Infection Microbiology, 2022) Paloma Abad; Patricia Marín-García; Marcos Heras; Julius N. Fobil; Alfred G. Hutchful; Díez Martín, Amalia; Puyet Catalina, Antonio; Reyes Palomares, Armando Adolfo; Isabel G. Azcárate; Bautista Santa Cruz, José ManuelAssessment of serological Plasmodium falciparum-specific antibodies in highly endemic areas provides valuable information about malaria status and parasite exposure in the population. Although serological evidence of Plasmodium exposure is commonly determined by Plasmodium-specific immunoglobulin G (IgG) levels; IgM and IgA are likely markers of malaria status that remain relatively unexplored. Previous studies on IgM and IgA responses have been based on their affinity for single antigens with shortage of immune responses analysis against the whole Plasmodium proteome. Here, we provide evidence of how P. falciparum infection triggers the production of specific IgM and IgA in plasma and its relationship with parasite density and changes in hematological parameters. A total of 201 individuals attending a hospital in Breman Asikuma, Ghana, were recruited into this study. Total and P. falciparum-specific IgM, IgA, and IgG were assessed by ELISA and examined in relation to age (0-5, 14-49, and ≥50 age ranges); infection (submicroscopic vs. microscopic malaria); pregnancy and hematological parameters. Well-known IgG response was used as baseline control. P. falciparum-specific IgM and IgA levels increased in the population with the age, similarly to IgG. These data confirm that acquired humoral immunity develops by repeated infections through the years endorsing IgM and IgA as exposure markers in endemic malaria regions. High levels of specific IgA and IgM in children were associated with microscopic malaria and worse prognosis, because most of them showed severe anemia. This new finding shows that IgM and IgA may be used as diagnostic markers in this age group. We also found an extremely high prevalence of submicroscopic malaria (46.27% on average) accompanied by IgM and IgA levels indistinguishable from those of uninfected individuals. These data, together with the observed lack of sensitivity of rapid diagnostic tests (RDTs) compared to PCR, invoke the urgent need to implement diagnostic markers for submicroscopic malaria. Overall, this study opens the potential use of P. falciparum-specific IgM and IgA as new serological markers to predict malaria status in children and parasite exposure in endemic populations. The difficulties in finding markers of submicroscopic malaria are highlighted, emphasizing the need to explore this field in depth.- Project number: 146
Item Estrategias colaborativas de integración de recursos docentes en línea para la mejora del proceso de enseñanza/aprendizaje del Grado en Veterinaria entre las facultades españolas donde se imparte dicha titulación(2021) Gagete Camargo, María Victoria; García-Cuevas Roque, María Carmen; Martínez Martín, Cesar; Arias Álvarez, María; Cabeza Briales, María Concepción; Castro Madrigal, Teresa; Cambero Rodríguez, María Isabel; Fernández Álvarez, Manuela; Martínez De Merlo, Elena; Pérez Cabal, María De Los Ángeles; Pérez Sen, Raquel; Serres Dalmau, María Consolacion; Díez Martín, AmaliaLa emergencia sanitaria por la pandemia COVID-19 afectó al desarrollo académico del Curso 2019-20 de tal manera que, en un periodo de tiempo escaso, las Universidades tuvieron que virar de forma urgente hacia un modelo de enseñanza-aprendizaje a distancia. Todos los planes de estudio cuidadosamente construidos cambiaron de repente hacia una docencia y una evaluación que se tuvo que desarrollar completamente en línea. La evolución de la pandemia impidió la vuelta a una enseñanza presencial completa para el Curso 2020-21 y nos obligó a plantear la docencia en un nuevo escenario semipresencial en donde el uso de herramientas virtuales para la adquisición de competencias de los estudiantes es necesario. El proyecto pretende compartir experiencias docentes y metodologías didácticas innovadoras desarrolladas por profesorado del Grado en Veterinaria que faciliten la docencia ante distintas eventualidades. Este proyecto brinda una gran oportunidad al profesorado, que tuvo que enfrentarse a una situación académica sin precedentes, para reflexionar, y detectar las debilidades del material docente que se preparó con urgencia y mejorarlas. - Project number: 244
Item Elaboración y desarrollo de materiales accesibles para la formación de jóvenes con discapacidad intelectual en la atención y cuidado de animales, mediante la intervención en el Proyecto Liceo(2022) Encinas Cerezo, María Teresa; Pablo Moreno, Juan Andrés de; Águeda Gómez, Alejandra de; De Las Heras Molina, Ana; Fernández Bravo, Juan Antonio; Fernández de Lys Galván, Gonzalo; Fuertes Recuero, Manuel; Gilabert Santos, Juan Antonio; Marín García, María Del Pilar; Morón Elorza, Pablo; Nieto González, David; Olivos Ore, Luis Alcides; Ortega Moreno, Carlos; Barbacid Yela, Andrea; Maqueda Olivas, Clara María; Arribas Blázquez, Marina; Díez Martín, AmaliaProfesionales especializados en Veterinaria y Educación Especial desarrollarán materiales cognitivamente accesibles para jóvenes con discapacidad intelectual aplicables a los contenidos del itinerario de Cuidado de Animales del Proyecto Liceo. Item Glutathione peroxidase contributes with heme oxygenase-1 to redox balance in mouse brain during the course of cerebral malaria(Biochimica et Biophysica Acta (BBA) - Molecular Basis of Disease, 2013) Linares Gómez, María; Marín-García, Patricia; Martínez-Chacón, Gabriela; Pérez-Benavente, Susana; Puyet Catalina, Antonio; Díez Martín, Amalia; Bautista Santa Cruz, José ManuelOxidative stress has been attributed both a key pathogenic and rescuing role in cerebral malaria (CM). In a Plasmodium berghei ANKA murine model of CM, host redox signaling and functioning were examined during the course of neurological damage. Host antioxidant defenses were early altered at the transcriptional level indicated by the gradually diminished expression of superoxide dismutase-1 (sod-1), sod-2, sod-3 and catalase genes. During severe disease, this led to the dysfunctional activity of superoxide dismutase and catalase enzymes in damaged brain regions. Vitagene associated markers (heat shock protein 70 and thioredoxin-1) also showed a decaying expression pattern that paralleled reduced expression of the transcription factors Parkinson disease 7, Forkhead box O 3 and X-box binding protein 1 with a role in preserving brain redox status. However, the oxidative stress markers reactive oxygen/nitrogen species were not accumulated in the brains of CM mice and redox proteomics and immunohistochemistry failed to detect quantitative or qualitative differences in protein carbonylation. Thus, the loss of antioxidant capacity was compensated for in all cerebral regions by progressive upregulation of heme oxygenase-1, and in specific regions by early glutathione peroxidase-1 induction. This study shows for the first time a scenario of cooperative glutathione peroxidase and heme oxygenase-1 upregulation to suppress superoxide dismutase, catalase, heat shock protein-70 and thioredoxin-1 downregulation effects in experimental CM, counteracting oxidative damage and maintaining redox equilibrium. Our findings reconcile the apparent inconsistency between the lack of oxidative metabolite build up and reported protective effect of antioxidant therapy against CM.Item Proteomic Approaches to Identifying Carbonylated Proteins in Brain Tissue(Journal of Proteome Research (JPR), 2011) Linares Gómez, María; Marín-García, Patricia ; Méndez, Darío ; Puyet Catalina, Antonio; Díez Martín, Amalia; Bautista Santa Cruz, José ManuelOxidative stress plays a critical role in the pathogenesis of a number of diseases. The carbonyl end products of protein oxidation are among the most commonly measured markers of oxidation in biological samples. Protein carbonyl functional groups may be derivatized with 2,4-dinitrophenylhydrazine (DNPH) to render a stable 2,4-dinitrophenylhydrazone-protein (DNP-protein) and the carbonyl contents of individual proteins then determined by two-dimensional electrophoresis followed by immunoblotting using specific anti-DNP antibodies. Unfortunately, derivatization of proteins with DNPH could affect their mass spectrometry (MS) identification. This problem can be overcome using nontreated samples for protein identification. Nevertheless, derivatization could also affect their mobility, which might be solved by performing the derivatization step after the initial electrophoresis. Here, we compare two-dimensional redox proteome maps of mouse cerebellum acquired by performing the DNPH derivatization step before or after electrophoresis and detect differences in protein patterns. When the same approach is used for protein detection and identification, both methods were found to be useful to identify carbonylated proteins. However, whereas pre-DNPH derivatized proteins were successfully analyzed, high background staining complicated the analysis when the DNPH reaction was performed after transblotting. Comparative data on protein identification using both methods are provided.Item Estandarización de un modelo murino de malaria cerebral en fases clínicas para la evaluación de terapias antimaláricas y de rescate(Anales de la Real Academia de Farmacia, 2013) Martínez, Gabriela; Linares Gómez, María; Marín-García, Patricia; Pérez-Benavente, Susana; Puyet Catalina, Antonio; Bautista Santa Cruz, José Manuel; Díez Martín, AmaliaEntre las enfermedades infecciosas más devastadoras del SNC se incluye la MC, debido a la alta mortalidad y las graves secuelas que ocasiona. Actualmente, no existe tratamiento farmacológico específico, ni de rescate de lesiones neurocognitivas residuales, y su desarrollo está limitado por la inexistencia de modelos experimentales bien definidos. En este trabajo se caracterizó fenotípicamente la infección en un modelo murino de MC evaluando parámetros clínicos que permitieron establecer cuatro estadios de la enfermedad. Este protocolo proporciona el marco experimental adecuado para estudiar terapias coadyuvantes neuroprotectoras que puedan prevenir y/o eliminar las secuelas neurológicas presentes en los individuos que sobreviven.Item Screening for retroviruses and hepatitis viruses using dried blood spots reveals a high prevalence of occult hepatitis B in Ghana(Therapeutic Advances in Infectious Disease, 2019) Carmen de Mendoza; Bautista Santa Cruz, José Manuel; Susana Pérez-Benavente; Roger Kwawu; Julius Fobil; Vicente Soriano; Díez Martín, AmaliaBackground: Recent advances in antiviral therapy show potential for a cure and/or control of most human infections caused by hepatitis viruses and retroviruses. However, medical success is largely dependent on the identification of the large number of people unaware of these infections, especially in developing countries. Dried blood spots (DBS) have been demonstrated to be a good tool for collecting, storing and transporting clinical specimens from rural areas and limited-resource settings to laboratory facilities, where viral infections can be more reliably diagnosed. Methods: The seroprevalence and virological characterization of hepatitis B virus (HBV) and hepatitis C virus (HCV), as well as human retroviruses (HIV-1, HIV-2, human T-cell leukaemia virus type 1 [HTLV-1] and human T-cell leukaemia virus type 2 [HTLV-2]), were investigated in clinical specimens collected from DBS in Ghana. Results: A total of 305 consecutive DBS were collected. A high prevalence of chronic HBV (8.5%) and occult hepatitis B (14.2%) was found, whereas rates were lower for HIV-1, HTLV-1 and HCV (3.2%, 1.3% and 0.6%, respectively). HIV-2 and HTLV-2 were absent. CRF02_AG was the predominant HIV-1 subtype, whereas genotype E was the most frequent HBV variant. Conclusions: DBS are helpful in the diagnosis and virological characterization of hepatitis and retrovirus infections in resource-limited settings. The high rate of hepatitis B in Ghana, either overt or occult, is noteworthy and confirms recent findings from other sub-Saharan countries. This should encourage close clinical follow up and antiviral treatment assessment in this population, as well as universal HBV vaccine campaigns.Item In vitro antiplasmodial activity of selected plants from the Colombian North Coast with low cytotoxicity(Tropical Parasitology, 2022) Saray Vergara; Fredyc Diaz; Díez Martín, Amalia; Bautista Santa Cruz, José Manuel; Carlos MonerizBackground: Plants are an important option in the treatment of malaria, especially in endemic regions, and are a less expensive and more accessible alternative with a lower risk of toxicity. Colombia has a great diversity of plants, and evaluation of natural extracts could result in the discovery of new compounds for the development of antimalarial drugs. The purpose of this work was to evaluate the in vitro antiplasmodial activity and the cytotoxicity of plant extracts from the Colombian North Coast against Plasmodium falciparum. Materials and Methods: The antiplasmodial activity of 12 plant species from the Colombian North Coast that are used in traditional medicine was evaluated through in vitro cultures of P. falciparum, and the cytotoxicity of extracts of these species to human cells was determined. Plant extracts with high antiplasmodial activity were subjected to preliminary phytochemical screening. Results: Extracts from five plants had promising antiplasmodial activity. Specifically, Bursera simaruba (Burseraceae) (bark), Guazuma ulmifolia Lam. (Malvaceae) (whole plant), Murraya exotica L. (Rutaceae) (leaves), Hippomane mancinella L. (Euphorbiaceae) (seeds), and Capparis odoratissima Jacq. (Capparaceae) (leaves). Extracts presented 50% inhibitory concentration values between 1 and 9 μg/ml. Compared to no extract, these active plant extracts did not show cytotoxic effects on mononuclear cells or hemolytic activity in healthy human erythrocytes. Conclusions: The results obtained from this in vitro study of antiplasmodial activity suggest that active plant extracts from the Colombian North Coast are promising for future bioassay-guided fractionation to allow the isolation of active compounds and to elucidate their mechanism of action against Plasmodium spp.Item Shotgun Characterization of the Circulating IgM Antigenome of an Infectious Pathogen by Immunocapture-LC–MS/MS from Dried Serum Spots(Journal of Proteome Research, 2024) Abad González, Paloma; Coronado Brieva, Montserrat; Vincelle-Nieto, África; Pérez Benavente, Susana; Fobil, Julius N.; Puyet Catalina, Antonio; Díez Martín, Amalia; Reyes Palomares, Armando Adolfo; Azcárate, Isabel G.; Bautista Santa Cruz, José ManuelOne of the main challenges in compiling the complete collection of protein antigens from pathogens for the selection of vaccine candidates or intervention targets is to acquire a broad enough representation of them to be recognized by the highly diversified immunoglobulin repertoire in human populations. Dried serum spot sampling (DSS) retains a large repertoire of circulating immunoglobulins from each individual that can be representative of a population, according to the sample size. In this work, shotgun proteomics of an infectious pathogen based on DSS sampling coupled with IgM immunoprecipitation, liquid chromatography–mass spectrometry (LC–MS/MS), and bioinformatic analyses was combined to characterize the circulating IgM antigenome. Serum samples from a malaria endemic region at different clinical statuses were studied to optimize IgM binding efficiency and antibody leaching by varying serum/immunomagnetic bead ratios and elution conditions. The method was validated using Plasmodium falciparum extracts identifying 110 of its IgM-reactive antigens while minimizing the presence of human proteins and antibodies. Furthermore, the IgM antigen recognition profile differentiated between malaria-infected and noninfected individuals at the time of sampling. We conclude that a shotgun proteomics approach offers advantages in providing a high-throughput, reliable, and clean way to identify IgM-recognized antigens from trace amounts of serum. The mass spectrometry raw data and metadata have been deposited with ProteomeXchange via MassIVE with the PXD identifier PXD043800.Item Brain-derived neurotrophic factor and the course of experimental cerebral malaria(Brain Research, 2013) Linares Gómez, María; Patricia Marín-García; Susana Pérez-Benavente; Jesús Sánchez-Nogueiro; Puyet Catalina, Antonio; Bautista Santa Cruz, José Manuel; Díez Martín, AmaliaThe role of neurotrophic factors on the integrity of the central nervous system (CNS) during cerebral malaria (CM) infection remains obscure, but the long-standing neurocognitive sequelae often observed in rescued children can be attributed in part to the modulation of neuronal survival and synaptic plasticity. To discriminate the contribution of key responses in the time-sequence of the pathogenic events that trigger the development of neurocognitive malaria syndrome we defined four stages (I–IV) of the neurological progression of CM in C57BL/6 mice infected with Plasmodium berghei ANKA. Upregulation of ICAM-1, VCAM-1, e-selectin and p-selectin expression was detected in all cerebral regions before parasitized red blood cells (pRBC) accumulation. As the severity of symptoms increased, BDNF mRNA progressively diminished in several brain regions, earliest in the thalamus–hypothalamus, cerebellum, brainstem and cortex, and correlated with a four-stage disease sequence. Immunohistochemical confocal microscopy revealed changes in the BDNF distribution pattern, suggesting altered axonal transport. During CM progression, molecular markers of neurological infection and inflammation in the parasite and the host, respectively, were accompanied by a switch in the brain constitutive proteasome to the immunoproteasome, which could impede normal protein turnover. In parallel with BDNF downregulation, NCAM expression also diminished with increased CM severity. Together, these data suggest that changes in BDNF availability could be involved in the pathogenesis of CM.