Browsing by Subject "Inflamación"

Now showing 1 - 12 of 12
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    Apoptosis-associated speck-like protein containing CARD forms specks but does not activate caspase-1 in the absence of NLRP3 during macrophage swelling
    (The American Association of Immunologists, Inc., 2015) Compan, Vincent; Martín-Sánchez, Fátima; Baroja-Mazo, Alberto; López-Castejón, Gloria; Gomez, Ana I.; Verkhratsky, Alexei; Brough, David; Pelegrin Vivancos, Pablo; Bioquímica y Biología Molecular B e Inmunología
    Apoptosis-associated speck-like protein containing a CARD (ASC) is a key adaptor molecule required for inflammatory processes. ASC acts by bridging NLRP proteins, such as NLRP3, with pro-caspase-1 within the inflammasome complex that subsequently results in the activation of caspase-1 and the secretion of interleukin (IL)-1b and IL-18. In response to bacterial infection, ASC also forms specks by self-oligomerization to activate caspase-1 and induce pyroptosis. Hitherto the role of these specks in NLRP3 inflammasome activation in response to danger signals is largely unexplored. Here we report that under hypotonic conditions, ASC formed specks independently of NLRP3 that did not activate caspase-1. These specks were not associated with pyroptosis and were controlled by Transient Receptor Potential Vanilloid 2 channel mediated signaling. However, interaction with NLRP3 enhanced ASC speck formation leading to fully functional inflammasomes and caspase-1 activation. This study reveals that the ASC speck could present different oligomerization assemblies and represents an essential step in the activation of functional NLRP3 inflammasomes.
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    Cell volume regulation modulates NLRP3 inflammasome activation
    (Cell Press, 2012) Compan, Vincent; Baroja-Mazo, Alberto; Lopez-Castejón, Gloria; Gomez, Ana I.; Martínez, Carlos M.; Angosto, Diego; Montero, María T.; Herranz, Antonio S.; Bazán, Eulalia; Reimers, Diana; Mulero, Victoriano; Pelegrín Vivancos, Pablo; Bioquímica y Biología Molecular B e Inmunología
    Cell volume regulation is a primitive response to alterations in environmental osmolarity. The NLRP3 inflammasome is a multiprotein complex that senses pathogen- and danger-associated signals. Here we report that the basic mechanisms of cell swelling and regulatory volume decrease (RVD) are sensed from fish to mammals by the NLRP3 inflammasome. We found that a decrease in extracellular osmolarity induced (i) a K+-dependent conformational change of the preassembled NLRP3-inactive inflammasome during cell swelling, followed by (ii) activation of the NLRP3 inflammasome and caspase-1, which was controlled by Transient Receptor Potential (TRP) channels during RVD. Both mechanisms were necessary for interleukin-1b processing. Increased extracellular osmolarity prevented caspase-1 activation by different known NLRP3 activators. Collectively, our data place cell volume regulation as a basic conserved homeostatic mechanism associated with the formation of the NLRP3 inflammasome and provides a mechanism for NLRP3 inflammasome activation.
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    Dynamics of macrophage polarization reveal new mechanism to inhibit IL-1beta release through pyrophosphates
    (EMBO Press, 2009) Pelegrin, Pablo; Surprenant, Annmarie; Bioquímica y Biología Molecular B e Inmunología
    In acute inflammation extracellular ATP activates P2X7 ion channel receptors (P2X7R) on M1 polarized macrophages to release pro-inflammatory IL-1bvia activation of the caspase-1/Nucleotide-binding domain and Leucine-rich repeat receptor containing Pyrin domain 3 (NLRP3) inflammasome. In contrast, M2 polarized macrophages are critical to the resolution of inflammation but neither actions of P2X7R on these macrophages, nor mechanisms by which macrophages switch from pro-inflammatory to anti-inflammatory phenotypes, are known. Here we investigated extracellular ATP signaling over a dynamic macrophage polarity gradient from M1 through M2 phenotypes. In macrophages polarized towards, but not at, M2 phenotype, where intracellular IL-1b remains high and the inflammasome is intact, P2X7R activation selectively uncouples to the NLRP3-inflammasome activation but not to upstream ion channel activation. In these intermediate M1/M2 polarized macrophages, extracellular ATP now acts via its pyrophosphate chains, independently of other purine receptors, to inhibit IL-1b release by other stimuli via two independent mechanisms: inhibition of ROS production and trapping of the inflammasome complex via intracellular clustering of actin filaments.
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    Eficacia de la Cúrcuma Longa (Zingiberacea) vs. Clorhexidina al 0.2% contra bacterias periodontales : estudio in vitro
    (Universidad de Murcia, 2024-11-13) Carpio González, Ana María de las Mercedes; Camacho Alonso, Fabio; Corigliano, Massimo; Escuela Internacional de Doctorado
    En los últimos años, se ha despertado el interés por los agentes antimicrobianos naturales debido a la alta resistencia bacteriana. La Cúrcuma Longa una planta perenne que pertenece a la familia Zingiberaceae, ha generado el interés de la comunidad científica debido a sus propiedades antimicrobianas y antiinflamatorias. Objetivo: Determinar la eficacia antibacteriana de los extractos de Cúrcuma L. a diferentes concentraciones vs. la Clorhexidina al 0.2%, en cepas periodontales in vitro: (Porphyromonas gingivalis ATTC ® 33277, Tanneretta forsythia ATTC 43037, Treponema denticola ATTC ®35405, Peptostreptococcus micros ATTC ®33270 y Aggregatibacter actinomycetemcomitans ®ATTC 3338). Metodología: Se diseñó un estudio experimental de tipo exploratorio, analítico y según su temporalidad, de tipo longitudinal. Se prepararon diferentes tipos de extractos (etanólico, metanólico y acuoso) de Cúrcuma de la India y de la Cúrcuma cultivada en la República Dominicana, y se prepararon soluciones de Cúrcuma a diferentes concentraciones de cada una (100, 50, 25, 12.50, 6.25, 3.125, 1.562, 0.780, 0.390, 0.195 mg/ml). Se realizaron 5 repeticiones con cada grupo para una muestra total de 185 réplicas. Para evaluar la eficacia antibacteriana de la Cúrcuma y la Clorhexidina al 0.2%, se utilizó el método por difusión de discos y se modificó utilizando los medios de cultivos nutritivos y los requerimientos para cada cepa según el Global Bioresource Center (ATTC). Determinamos la eficacia de los extractos de Cúrcuma L. y de la Clorhexidina al 0.2% midiendo el halo de eficacia en mm. Resultados: Se observó que la Cúrcuma L. solamente tuvo eficacia frente a la Peptostreptococcus micros a concentración mínima de 50 mg/ml en los extractos (etanólico y metanólico) y a 100mg/ml en el (acuoso) con un promedio de halo de eficacia de 7mm, mientras que la Clorhexidina al 0.2 % mostró una mayor eficacia de todas las cepas analizadas con un promedio de halo de inhibición de 11.8 mm. Conclusión: Los extractos de los rizomas de la Cúrcuma L. presentaron un efecto antibacteriano frente a la Peptostreptococcus micros a una concentración mínima de 50mg/ml. La eficacia de la Clorhexidina en gel al 0.2% es superior a la de la Cúrcuma L. Se rechaza la hipótesis de igualdad entre ambos productos con un p valor = 0.00 < 0.05. La Clorhexidina sigue siendo el agente antiséptico tópico de uso en la terapia periodontal con una mayor eficacia antibacteriana.
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    Electrólisis percutánea intratisular y calidad de la atención en la epicondilalgia crónica
    (2014-12-15) Minaya Muñoz, Francisco; Medina i Mirapeix, Francesc; Valera Garrido, Fermín; Facultad de Medicina
    Objetivos Desarrollar y evaluar indicadores fiables, válidos y útiles para medir la calidad a pacientes con epicondilalgia lateral. Evaluar la efectividad clínica y ecográfica a corto, medio y largo plazo de la técnica Electrólisis Percutánea Intratisular (EPI®) combinado con un programa de ejercicios excéntricos y estiramientos sobre la epicondilalgia lateral y determinar su coste-efectividad. Material y métodos Estudio de construcción y pilotaje de indicadores para pacientes con epicondilalgia lateral, y estudio clínico experimental con un grupo y medidas repetidas (inicio, alta y a 6, 26 y 52 semanas de seguimiento). Para medir la calidad de la atención prestada a los pacientes con epicondilalgia lateral se llevó a cabo el desarrollo de diferentes indicadores de calidad por un grupo multidisciplinar de expertos en Gestión de la Calidad de los Servicios de la Salud. El proceso se basó en tres pasos bien estructurados. En el estudio clínico a los pacientes se les aplicó una sesión de EPI® a la semana durante 4-6 semanas, asociado a un programa de ejercicios excéntricos y estiramientos. Las principales variables de resultado que se midieron fueron la severidad del dolor (mediante EVA, algometría de presión, test ortopédicos), la discapacidad (cuestionario DASH), los cambios estructurales en el tendón y la hipervascularización (ecografía), y la percepción del paciente de los resultados obtenidos (escala de 4 puntos). Por otro lado, se valoró la relación de coste-efectividad de la intervención terapéutica. El coste por proceso se analizó comparándolo con los casos quirúrgicos y el gasto asociado y se basó sobre criterios de reducción de la intensidad del dolor. Resultados Se desarrollaron 12 indicadores fiables (Kappa>0.8) para medir la valoración y tratamiento. Hubo mejoras clínicas y ecográficas significativas al alta y ausencia de recidivas durante el seguimiento. Se estima que el coste por paciente del tratamiento con EPI® es 16 veces inferior que con cirugía. Conclusiones • Los indicadores de calidad construidos son fiables, basados en la evidencia y aplicables a los pacientes con epicondilalgia lateral. • El tratamiento con EPI® asociado con un programa de ejercicios excéntricos y estiramientos mejora los síntomas y regenera el tejido, con una relación coste-efectividad muy aceptable. ABSTRACT Aims To develop and evaluate reliable, valid and useful clinical quality measures (QMs) which may be used in the process of care of patients with lateral epicondylalgia. To assess the clinical and ultrasonographic effectiveness of Intratissue Percutaneous Electrolysis (the EPI® technique) combined with a program of eccentric exercise (EccEx) and stretching in the short, medium and long term for patients with lateral epicondylalgia and to determine its cost-effectiveness. Material and methods Study of construction and piloting testing of indicators for patients with lateral epicondylalgia was carried out, and experimental clinical design with a group and repeated measures (baseline, discharge and 6, 26 and 52 weeks follow-up). To measure the quality of care provided to patients with lateral epicondylalgia the development of different quality indicators was carried out by a multidisciplinary group of experts in Quality Management of Health Services. The process was based on three well-structured steps. In the clinical design, the patients received one session of US-guided EPI® technique per week over 4-6 weeks, associated with a home program of EccEx and stretching. The main outcome variables measured were pain severity (using EVA, pressure algometry, orthopedic test), disability (DASH questionnaire), structural changes in the tendon and hypervascularity (ultrasound), and patient’s perceptions of overall outcome (4 point scale). On the other hand, the ratio of cost-effectiveness of therapeutic intervention was assessed. The cost per case was analyzed by comparing it with surgical cases and the associated expense and was based on criteria for decreasing pain intensity. Results A set of 12 reliable indicators (Kappa > 0.8) was developed to measure the assessment and treatment. There were significant clinical and ultrasonographic improvements at discharge and no recurrences during follow-up period. It is estimated that the cost per patient of treatment with EPI® technique is 16 times lower than with surgery. Conclusions • The built quality indicators are reliable, evidence-based and applicable to patients with lateral epicondylalgia. • Treatment with the EPI® technique combined with a program of eccentric exercise (EccEx) and stretching improves symptoms and regenerates tissue, with a very acceptable cost-effectiveness ratio.
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    Extracellular ATP activates the NLRP3 inflammasome and is an early danger signal of skin allograft rejection
    (Cell Press, 2017) Amores-Iniesta, Joaquín; Barberá-Cremades, Maria; Martínez, Carlos M.; Pons, José A.; Revilla-Nuín, Beatriz; Martínez-Alarcón, Laura; Di Virgilio, Francesco; Parrilla, Pascual; Baroja-Mazo, Alberto; Pelegrín, Pablo; Bioquímica y Biología Molecular B e Inmunología
    Immune cells are equipped with a number of receptors that recognize sterile injury and pathogens. We find that host immune cells release ATP as an inflammatory signal in response to allogeneic transplantation. ATP then acts via a feedback mechanism on the P2X7 channel to activate the NLRP3 inflammasome and subsequently process and release interleukin (IL)-18. This process is a necessary stage in the deleterious Th1 response against allotransplantation via interferon-g production. Lack of IL-18 resulted in a decrease in graft- infiltrated CD8 cells, but an increase in regulatory T cells. In human liver transplant patients subjected to progressive immunosuppressive drug withdrawal, we found that patients suffering acute rejection had higher levels of the P2X7 receptor in circulating inflammatory monocytes compared to tolerant patients. These data suggest that the pharmacological inhibition of the P2X7 receptor or the NLRP3 inflammasome will aid in inducing transplant tolerance without complete immunoparalysis.
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    Inflammasome-dependent IL-1β release depends upon membrane permeabilisation
    (Nature, 2016) Martín-Sáncez, Fátima; Diamon, Catherine; Zeitler, Marcel; Gomez-Sanchez, Ana; Baroja-Mazo, Alberto; Bagnall, James; Spiller, David; White, Michael; Daniels, Michael J. D.; Mortellaro, Alessandra; Peñalver, Marcos; Paszek, Pawel; Steringer, Julia P.; Nickel, Walter; Brough, David; Pelegrin Vivancos, Pablo; Bioquímica y Biología Molecular B e Inmunología
    Interleukin (IL)-1β is a critical regulator of the inflammatory response. IL-1β is not secreted through the conventional ER-Golgi route of protein secretion and to-date its mechanism of release has been unknown. Crucially its secretion depends upon the processing of a precursor form following the activation of the multi-molecular inflammasome complex. Using a novel and reversible pharmacological inhibitor of the IL-1β release process, in combination with biochemical, biophysical and real-time single-cell confocal microscopy with macrophage cells expressing Venus labelled IL-1β, we have discovered that the secretion of IL-1β after inflammasome activation requires membrane permeabilisation, and occurs in parallel with the death of the secreting cell. Thus in macrophages the release of IL-1β in response to inflammasome activation appears to be a secretory process independent of non-specific leakage of proteins during cell death. The mechanism of membrane permeabilisation leading to IL-1β release is distinct from the unconventional secretory mechanism employed by its structural homologues FGF2 or IL-1α, a process that involves the formation of membrane pores but does not result in cell death. These discoveries reveal key processes at the initiation of an inflammatory response and deliver new insights into mechanisms of protein release.
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    Neuroinflammation and gliosis in the injured and contralateral retinas after unilateral optic nerve crush
    (Elsevier, 2023-08-22) Cabrera Maqueda, José María; Boia, Raquel; Lucas Ruiz, Fernando; González Riquelme, María José; Ambrosio, Antonio Francisco; Santiago, Ana Raquel; Vidal Sanz, Manuel; Agudo Barriuso, Marta; Galindo Romero, Caridad; Oftalmología, Optometría, Otorrinolaringología y Anatomía Patológica
    The main purpose of this study is to analyze the effects of unilateral optic nerve crush in the gene expression of pro- and anti-inflammatory mediators, and gliosis markers in injured and contralateral retinas. Retinas from intact, unilaterally optic nerve injured or sham-operated C57BL/6J mice were analyzed 1, 3, 9 and 30 days after the surgery (n = 5/group and time point) and the relative expression of TGF-β1, IL-1β, TNF-α, Iba1, AQP4, GFAP, MHCII, and TSPO was analyzed in injured and contralateral using qPCR. The results indicated that compared with intact retinas, sham-operated animals showed an early (day 1) upregulation of IL-1β, TNF-α and TSPO and a late (day 30) upregulation of TNF-α. In sham-contralateral retinas, TNF-α and TSPO mRNA expression were upregulated and day 30 while GFAP, Iba1, AQP4 and MHCII downregulated at day 9. Compared with sham-operated animals, in retinas affected by optic nerve crush GFAP and TSPO upregulated at day 1 and TNF-α, Iba1, AQP4 and MHCII at day 3. In the crushed-contralateral retinas, TGF-β1, TNF-α, Iba1 and MHCII were upregulated at day 1. TSPO was upregulated up to day 30 whereas TGF-β1 and Iba1 downregulated after day 9. In conclusion, both sham surgery and optic nerve crush changed the profile of inflammatory and gliosis markers in the injured and contralateral retinas, changes that were more pronounced for optic nerve crush when compared to sham.
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    P2X7 receptor differentially couples to distinct release pathways for IL-1b in mouse macrophage
    (The American Association of Immunologists, Inc., 2008) Pelegrin, Pablo; Barroso-Gutierrez, Consuelo; Surprenant, Annmarie; Bioquímica y Biología Molecular B e Inmunología
    The pro-inflammatory IL-1 cytokines, IL-1a, IL-1b and IL-18, are key mediators of the acute immune response to injury and infection. Mechanisms underlying their cellular release remain unclear. Activation of purinergic P2X7 receptors (P2X7R) by extracellular ATP is a key physiological inducer of rapid IL-1brelease from LPS-primed macrophage. We investigated patterns of ATP-mediated release of IL-1 cytokines from three macrophage types in attempts to provide direct evidence for or against distinct release mechanisms. We used peritoneal macrophage from P2X7R-/- mice and found that release of IL-1a, IL-18, as well as IL-1b, by ATP resulted exclusively from activation of P2X7R, that release of all these IL-1 cytokines involved pannexin-1 (panx1), and that there was both a panx1-dependent and independent component to IL-1b release. We compared IL-1 release patterns from LPS-primed peritoneal macrophage, RAW264.7 macrophage and J774A.1 macrophage. We found RAW264.7 macrophage readily release pro-IL- 1b independently of panx1 but do not release mature IL-1b because they do not express apoptotic speck-like protein with a caspase-activating recruiting domain (ASC) and so have no caspase-1 inflammasome activity. We delineated two distinct release pathways: the well-known caspase-1 cascade mediating release of processed IL-1b that was selectively blocked by inhibition of caspase-1 or panx1, and a calcium-independent, caspase-1/panx1-independent release of pro-IL-1b that was selectively blocked by glycine. None of these release responses were associated with cell damage or cytolytic effects. This provides the first direct demonstration of a distinct signaling mechanism responsible for ATP-induced release of pro-IL-1b.
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    P2X7 receptor-stimulation causes fever via PGE2 and IL-1beta release
    (Wiley, 2012) Barbera-Cremades, Maria; Baroja-Mazo, Alberto; Gomez, Ana I.; Machado, Francisco; Di Virgilio, Francesco; Pelegrin Vivancos, Pablo; Bioquímica y Biología Molecular B e Inmunología
    Prostaglandins (PG) are important lipid mediators involved in the development of inflammatory associated pain and fever. PGE2 is a well-established endogenous pyrogen activated by pro-inflammatory cytokine interleukin (IL)-1 . P2X7 receptors (P2X7R) expressed by inflammatory cells are stimulated by the danger signal extracellular ATP to activate the inflammasome and release IL-1 . Here we show that P2X7R activation is required for the release of PGE2 and other autacoids independent of inflammasome activation, with an ATP EC50 for PGE2 and IL-1 release of 1.58 and 1.23 mM, respectively. Furthermore, lack of P2X7R or specific antagonism of P2X7R decreased the febrile response in mice triggered after intra peritoneal (i.p.) LPS or IL-1 inoculation. Accordingly, LPS inoculation caused intraperitoneal ATP accumulation. Therefore, P2X7R antagonists emerge as novel therapeutics for the treatment for acute inflammation, pain and fever, with wider anti-inflammatory activity than currently used cyclooxygenase inhibitors.
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    The inflammasome adaptor protein ASC promotes amyloid deposition in cryopyrin-associated periodic syndromes
    (EMBO Press, 2025) Alarcón-Vila, Cristina; Hurtado-Navarro, Laura; Mateo, Sandra V; Peñín-Franch, Alejandro; Martínez, Carlos M; Molina-López, Cristina; Baños, Maria C; Gómez, Ana I; Gómez-Román, Jorge; Baroja-Mazo, Alberto; Arostegui, Juan I; Palmou-Fontana, Natalia; Martínez-García, Juan J; Pelegrin, P; Bioquímica y Biología Molecular B e Inmunología
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    The NLRP3 inflammasome is released as a particulate danger signal that amplifies the inflammatory response
    (Nature, 2014) Baroja-Mazo, Alberto; Martín-Sánchez, Fátima; Gomez, Ana I.; Martínez, Carlos M.; Amores-Iniesta, Joaquín; Compan, Vincent; Barberá-Cremades, María; Yagüe, Jordi; Ruiz-Ortiz, Estibaliz; Antón, Jordi; Buján, Segundo; Couillin, Isabelle; Brough, David; Arostegui, Juan I.; Pelegrin Vivancos, Pablo; Bioquímica y Biología Molecular B e Inmunología
    NLRP3 inflammasome assembly activates caspase-1 and mediates the processing and release of the leaderless cytokine IL-1β, and thereby plays a central role in the inflammatory response and in diverse human diseases. Here we report that upon caspase-1 activation oligomerized NLRP3-inflammasome particles are released from macrophages. Recombinant oligomeric protein particles composed of the adapter protein ASC or the cryopyrin-associated periodic syndromes (CAPS) mutant NLRP3 p.D303N, stimulate further caspase-1 activation extracellularly, and also intracellularly upon phagocytosis by surrounding macrophages. ASC oligomeric particles were found in the serum of patients with active CAPS, but not in patients with other inherited autoinflammatory diseases. Our findings support a model whereby the NLRP3-inflammasome, acting as an extracellular oligomeric complex, amplifies the inflammatory response.