Browsing by Subject "LPS"
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- PublicationRestrictedAnalysis of key proinflammatory mechanisms in cardiovascular pathology through stimulation with lipopolysaccharide and urban particulate matter in mouse atrial cardiomyocytes(Elsevier, 2025-02-09) Mandaglio-Collados, Darío; Ruiz Alcaraz, Antonio José; Rivera Caravaca, José Miguel; Ramos-Bratos, María Pilar; Marín Ortuño, Francisco; López Gálvez, Raquel; Bioquímica y Biología Molecular B e Inmunología; Facultad de BiologíaAir pollution has emerged as one of the leading causes of mortality, aggravating cardiovascular diseases. Urban-particulate matter (PM) can accumulate in the cardiovascular system and through inflammation, trigger systemic damage. One of the key mechanisms of this process could be related to the activation of the inflammasome through the pre-existence of a low-grade endotoxemia and PM presence in the cells. Herein, we studied the deleterious effects of urban-PM and Lipopolysaccharide (LPS) exposure in a HL-1 mouse cardiomyocyte cell line. Urban-PM induced biological changes, including mRNA expression of pro-inflammatory genes, intracellular reactive oxygen species (ROS) generation and overexpression of inflammasome-related and structural proteins. The results revealed that urban-PM with different ultrastructure, as determined by transmission electron microscopy (TEM), is embedded inside the cardiomyocytes, leading to the recognition and activation of the inflammatory process. The increase of ROS levels and mRNA levels of pro-inflammatory genes were similarly observed in a dose-dependent manner. In addition, components and proteins of the inflammasome such as associated speck-like protein containing a CARD (ASC), caspase-1 and IL-1β were differentially overexpressed in treated HL-1 cells, as well as structural proteins like Connexin 43 (Cx43). These results provide new insights into the mechanisms that mediate innate pro-inflammatory activation in cardiomyocytes in response to air suspension pollutants.
- PublicationOpen AccessAromadendrin alleviates LPS-induced kidney apoptosis and inflammation by inhibiting phosphorylation of MAPK and NF-κB signaling pathways(Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2025) Ma, Xiaohong; Liu, Wenhua; Wang, Bin; Shi, FeizhuangBackground. Excessive inflammation and apoptosis in kidneys are critical players in the pathogenesis of acute kidney injury (AKI). Aromadendrin is a natural flavonoid characterized by anti-inflammatory, anti-apoptotic, and antioxidant actions. Thus, we investigated the roles and mechanisms of aromadendrin in the development of AKI. Methods. Lipopolysaccharide (LPS) was used to induce AKI mice, and one hour after LPS challenge, the mice received oral administration of aromadendrin or vehicle. Renal functions were assessed by measuring blood urea nitrogen and creatinine in serum. Histological changes were determined by hematoxylin and eosin staining. Apoptotic cells of renal tissues were detected by TUNEL staining. Gene expression was measured by western blotting and RT-qPCR. Results. Aromadendrin alleviated LPS-induced renal dysfunctions and histological defects in mice. Additionally, aromadendrin suppressed excessive inflammation and tissue apoptosis in the kidneys of LPS-induced AKI mice. Mechanistically, aromadendrin blocked the activation of NF-κB and MAPK pathways in LPS-induced AKI mice. Conclusion. Aromadendrin alleviates LPS-stimulated inflammation and tissue cell apoptosis in kidneys by inactivating the NF-κB and MAPK pathways
- PublicationRestrictedArtemisia pollen is the main vector for airborne endotoxin(Elsevier, 2018-08-09) Oteros, José; Bartusel, Elke; Alessandrini, Francesca; Núñez, Andrés; Moreno, Diego A.; Behrendt, Heidrun; Schmidt-Weber, Carsten; Traidl-Hoffmann, Claudia; Buters, Jeroen; Genética y MicrobiologíaBackground: Endotoxin (LPS) released from gram-negative bacteria causes strong immunologic and inflammatory effects and, when airborne, can contribute to respiratory conditions, such as allergic asthma. Objectives: We sought to identify the source of airborne endotoxin and the effect of this endotoxin on allergic sensitization. Methods: We determined LPS levels in outdoor air on a daily basis for 4 consecutive years in Munich (Germany) and Davos (Switzerland). Air was sampled as particulate matter (PM) greater than 10 μm (PM > 10) and PM between 2.5 and 10 μm. LPS levels were determined by using the recombinant Factor C assay. Results: More than 60% of the annual endotoxin exposure was detected in the PM > 10 fraction, showing that bacteria do not aerosolize as independent units or aggregates but adhered to large particles. In Munich 70% of annual exposure was detected between June 12th and August 28th. Multivariate modeling showed that endotoxin levels could be explained by phenological parameters (ie, plant growth). Indeed, days with high airborne endotoxin levels correlated well with the amount of Artemisia pollen in the air. Pollen collected from plants across Europe (100 locations) showed that the highest levels of endotoxin were detected on Artemisia vulgaris (mugwort) pollen, with little on other pollen. Microbiome analysis showed that LPS concentrations on mugwort pollen were related to the presence of Pseudomonas species and Pantoea species communities. In a mouse model of allergic disease, the presence of LPS on mugwort pollen was needed for allergic sensitization. Conclusions: The majority of airborne endotoxin stems from bacteria dispersed with pollen of only one plant: mugwort. This LPS was essential for inducing inflammation of the lung and allergic sensitization.
- PublicationOpen AccessDifferential severity of LPS-induced lung injury in CD26/DPP4 positive and deficient F344 rats(2019) Zientara, Alicja; Stephan, Michael; von Hörsten, Stephan; Schmied, AndreasBackground. Lipopolysaccharide (LPS) induced inflammation often leads to lung injury, in which pulmonary recruitment of neutrophils plays a pivotal role. Inflammatory processes are influenced by CD26/DPP4, highly expressed in lungs. Asthma induced CD26/DPP4 deficient (CD26/DPP4 - ) Fischer (F) 344 rats suffering from a transport block in the rER caused by a point mutation showed reduced pulmonary inflammation and reduced expression of immuno- modulating surfactant proteins (SP). The degree of LPS induced lung injury in CD26/DPP4 deficient rats has not been investigated so far. Objective. We hypothesize that LPS induced lung injury leads not only to an attenuated inflammation but also to a reduced SP expression and decreased structural damage in CD26/DPP4 - rats. Methods. Both genotypes were intratracheally instilled with 250 μl LPS or with 250 μl 0.9% NaCl. Nine hours later animals were killed and either bronchoalveolar lavage was carried out to determine inflammatory cells and surface tension or lung blocks were removed and processed for histology, immunohistochemistry, electron microscopy or qRt-PCR analyses and Western Blot analyses. Results. Signs of acute lung injury, such as structural damage of the blood gas barrier occurred only sporadically in both genotypes. LPS-induced CD26/DPP4 - rats showed decreased gene expression of SP-A and SP-D and reduced signs of lung inflammation associated with a reduced alveolar influx of macrophages and neutrophils. Conclusions. Less pulmonary inflammation combined with less structural alterations and minor expression of immunomodulating SP may be an indication of the critical role of CD26/DPP4 in regulating lung inflammation
PublicationOpen AccessEvaluación y seguimiento de la carga interna y externa para la monitorización de la fatiga durante la pretemporada en deportistas de élite de deportes colectivos indoor(2025-04-08) Moreno Villanueva, Adrián; Rico González, Markel; Pino Ortega, José; Facultades, Departamentos, Servicios y Escuelas::Departamentos de la UMU::Actividad Física y del Deporte; Facultad de Ciencias del Deporte; Departamento de Actividad F�sica y del DeporteLa evaluación y seguimiento de la carga interna y externa son fundamentales para la monitorización de la fatiga en deportistas de élite, especialmente durante la pretemporada, que es una fase crítica en la preparación para la competencia. En los deportes colectivos indoor, como el balonmano, el voleibol o el baloncesto, los atletas deben enfrentarse a cargas físicas intensas y a un alto volumen de entrenamiento para optimizar su rendimiento. Sin embargo, este proceso puede generar un incremento en el riesgo de fatiga, lesiones y disminución del rendimiento si no se maneja adecuadamente. Para evitarlo, es esencial realizar un seguimiento detallado tanto de la carga externa, que se refiere a la magnitud del esfuerzo físico que el deportista realiza durante las sesiones de entrenamiento, como de la carga interna, que refleja cómo el cuerpo responde a ese esfuerzo. La carga externa se puede cuantificar a través de dispositivos como los monitores de frecuencia cardíaca, los acelerómetros o los sistemas de localización en interiores, los cuales proporcionan datos objetivos sobre el volumen y la intensidad de la actividad realizada. Estos dispositivos permiten medir parámetros como la distancia recorrida, la velocidad, la aceleración, el número de sprints y el tiempo de actividad de alta intensidad. Esta información es crucial para entender las demandas físicas a las que se somete el deportista, así como para planificar el volumen de entrenamiento, evitando tanto el sobreentrenamiento como el subentrenamiento. Por otro lado, la carga interna se refiere a la respuesta fisiológica del cuerpo ante estas demandas, y se evalúa principalmente a través de la frecuencia cardíaca, la percepción del esfuerzo (medida por la escala de Borg) y otros biomarcadores como el lactato sanguíneo. La monitorización de la carga interna permite detectar señales tempranas de fatiga, lo cual es clave durante la pretemporada, ya que una acumulación de fatiga sin el debido control puede llevar a un estado de sobrecarga que afecte negativamente al rendimiento del deportista. Además, la fatiga no solo afecta al plano físico, sino también al plano mental, lo que podría influir en la toma de decisiones tácticas y técnicas durante los partidos. La combinación de ambos tipos de carga, interna y externa, proporciona una visión más completa del estado de fatiga del deportista y de su capacidad para recuperarse de los entrenamientos. El uso de estas herramientas en conjunto permite personalizar los programas de entrenamiento, ajustando la intensidad y el volumen según las necesidades de cada atleta. Esto es especialmente relevante en la pretemporada, cuando se busca optimizar el rendimiento físico sin comprometer la salud del deportista. Además, el seguimiento continuo de la fatiga facilita la identificación de posibles desequilibrios en el entrenamiento, lo que permite realizar ajustes en tiempo real para evitar la fatiga crónica o el riesgo de lesión. En resumen, la evaluación y el seguimiento de la carga interna y externa son elementos clave en la monitorización de la fatiga durante la pretemporada en los deportes colectivos indoor. Estas mediciones no solo ayudan a mejorar el rendimiento físico, sino que también contribuyen a una mejor planificación del ciclo de entrenamiento, garantizando que los deportistas lleguen en su mejor forma posible al inicio de la temporada competitiva. La implementación adecuada de estas metodologías garantiza un enfoque científico y personalizado, maximizando las posibilidades de éxito y minimizando los riesgos de lesiones o fatiga excesiva.- PublicationRestrictedEvolution of Lipopolysaccharide (LPS) Recognition and Signaling: Fish TLR4 Does Not Recognize LPS and Negatively Regulates NF-κB Activation(American Association of Immunologists Oxford University Press, 2009-02-15) Alcaraz-Perez, Francisca; López-Muñoz, Azucena; Meseguer Peñalver, J.; Cayuela Fuentes, Maria Luisa; Mulero Méndez, Victoriano Francisco; Sepulcre Cortés, María Pilar; Roca Soler, Francisco José; Bioquímica y Biología Molecular B e InmunologíaIt has long been established that lower vertebrates, most notably fish and amphibians, are resistant to the toxic effect of LPS. Furthermore, the lack of a TLR4 ortholog in some fish species and the lack of the essential costimulatory molecules for LPS activation via TLR4 (i.e., myeloid differentiation protein 2 (MD-2) and CD14) in all the fish genomes and expressed sequence tag databases available led us to hypothesize that the mechanism of LPS recognition in fish may be different from that of mammals. To shed light on the role of fish TLRs in LPS recognition, a dual-luciferase reporter assay to study NF-κB activation in whole zebrafish embryos was developed and three different bony fish models were studied: 1) the gilthead seabream (Sparus aurata, Perciformes), an immunological-tractable teleost model in which the presence of a TLR4 ortholog is unknown; 2) the spotted green pufferfish (Tetraodon nigroviridis, Tetraodontiformes), which lacks a TLR4 ortholog; and 3) the zebrafish (Danio rerio, Cypriniformes), which possesses two TLR4 orthologs. Our results show that LPS signaled via a TLR4- and MyD88-independent manner in fish, and, surprisingly, that the zebrafish TLR4 orthologs negatively regulated the MyD88-dependent signaling pathway. We think that the identification of TLR4 as a negative regulator of TLR signaling in the zebrafish, together with the absence of this receptor in most fish species, explains the resistance of fish to endotoxic shock and supports the idea that the TLR4 receptor complex for LPS recognition arose after the divergence of fish and tetrapods.
- PublicationOpen AccessHepatic macrophage activation and the LPS pathway in patients with different degrees of severity and histopathological patterns of drug induced liver injury(Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2021) Du, Hui-juan; Zhao, Su-xian; Zhao, Wen; Fu, Na; Li, Wen-cong; Qin, Xiao-jie; Zhang, Yu-guo; Nan, Yue-min; Zhao, Jing-minBackground. Inflammatory activation of hepatic macrophages plays a primary role in druginduced liver injury (DILI). However, the exact mechanism underlying DILI remains unclear. Methods. A total of 328 DILI patients and 80 healthy individuals were prospectively enrolled in this study. The DILI patients were categorized into subgroups based on either disease severity or histopathological patterns. Plasma soluble CD163 (sCD163) and hepatic CD163 were examined to determine hepatic macrophage activation, and CD8, CD20, and MUM-1 were assessed to determine cellular immunity using immunohistochemistry. The lipopolysaccharide (LPS) pathway proteins [e.g. LPS, soluble CD14 (sCD14), and LPSbinding protein (LBP)] were measured using enzymelinked immunosorbent assay. Results. Plasma sCD163 levels were nine-fold higher in DILI patients than in healthy controls at the baseline, but significantly decreased at the 4-week follow-up visit after treatment. The numbers of hepatic macrophages, B cells, and plasma cells were significantly higher in the liver tissues from DILI patients than those from healthy controls. Furthermore, the baseline levels of LPS pathway proteins in the DILI patients were significantly higher than those in the controls. Notably, these proteins significantly decreased at the 4-week follow-up visit but remained significantly higher than the levels for the controls. Conclusions. Hepatic inflammation in DILI involves the activation of hepatic macrophages and cellular immunity, in which the LPS pathway likely plays a role, at least in part. As such, this study has improved our understanding of the pathological mechanisms for DILI and may facilitate the development of better treatments for patients with DILI.
- PublicationOpen AccessMeasurement of procalcitonin in saliva of pigs: a pilot study(BMC, 2022-04-15) López Martínez, María Jose; Escribano, Damián; Martínez Miró, Silvia; Ramis, Guillermo; Manzanilla, Edgar G.; Tecles, Fernando; Martínez Subiela, Silvia; Cerón, Jose J.; Medicina y Cirugía AnimalBackground: Procalcitonin (PCT) is a widely used biomarker of sepsis in human medicine and can have potential applications in the veterinary field. This study aimed to explore whether PCT could be measured in the saliva of pigs and whether its concentration changes in sepsis. Therefore, a specific assay was developed and analytically validated, and changes in PCT concentration were evaluated in two conditions: a) in an experimental model of sepsis produced by the administration of lipopolysaccharide (LPS) to pigs (n = 5), that was compared with a model of non‑septic inflammation induced by turpentine oil (n = 4), and b) in healthy piglets (n = 11) compared to piglets with meningitis (n = 20), a disease that usually involves sepsis and whose treatment often requires large amounts of antibiotics in farms. Results: The assay showed coefficients of variation within the recommended limits and adequate linearity after serial sample dilutions. The method’s detection limit was set at 68 μg/L, and the lower limit of quantification was 414 μg/L. In the LPS experiment, higher concentrations of PCT were found after 24 h in the animals injected with LPS (mean = 5790 μg/L) compared to those treated with turpentine oil (mean = 2127 μg/L, P = 0.045). Also, animals with meningitis had higher concentrations of PCT (mean = 21515 μg/L) than healthy pigs (mean = 6096 μg/L, P value < 0.0001). Conclusions: According to these results, this assay could be potentially used as a tool for the non‑invasive detection of sepsis in pigs, which is currently a topic of high importance due to antibiotic use restriction.
- PublicationOpen AccessMMP-3 Deficiency Alleviates Endotoxin-Induced Acute Inflammation in the Posterior Eye Segment(MDPI, 2016-11-01) Van Hove, Inge; Lefevere, Evy; De Groef, Lies; Sergeys, Jurgen; Libert, Claude; Vandenbroucke, Rossmarijn; Moons, Lieve; Salinas Navarro, Manuel Ángel; Anatomía Humana y PsicobiologíaMatrix metalloproteinase-3 (MMP-3) is known to mediate neuroinflammatory processes by activating microglia, disrupting blood–central nervous system barriers and supporting neutrophil influx into the brain. In addition, the posterior part of the eye, more specifically the retina, the retinal pigment epithelium (RPE) and the blood–retinal barrier, is affected upon neuroinflammation, but a role for MMP-3 during ocular inflammation remains elusive. We investigated whether MMP-3 contributes to acute inflammation in the eye using the endotoxin-induced uveitis (EIU) model. Systemic administration of lipopolysaccharide induced an increase in MMP-3 mRNA and protein expression level in the posterior part of the eye. MMP-3 deficiency or knockdown suppressed retinal leukocyte adhesion and leukocyte infiltration into the vitreous cavity in mice subjected to EIU. Moreover, retinal and RPE mRNA levels of intercellular adhesion molecule 1 (Icam1), interleukin 6 (Il6), cytokine-inducible nitrogen oxide synthase (Nos2) and tumor necrosis factor α (Tnfα), which are key molecules involved in EIU, were clearly reduced in MMP-3 deficient mice. In addition, loss of MMP-3 repressed the upregulation of the chemokines monocyte chemoattractant protein (MCP)-1 and (C-X-C motif) ligand 1 (CXCL1). These findings suggest a contribution of MMP-3 during EIU, and its potential use as a therapeutic drug target in reducing ocular inflammation.
- PublicationRestrictedP2X7 receptor differentially couples to distinct release pathways for IL-1b in mouse macrophage(The American Association of Immunologists, Inc., 2008) Barroso-Gutierrez, Consuelo; Surprenant, Annmarie; Pelegrín Vivancos, Pablo; Bioquímica y Biología Molecular B e InmunologíaThe 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.
- PublicationOpen AccessThe regulation mechanism of apoptosis by visfatin in the mesenteric lymph nodes of LPS-treated rats(Universidad de Murcia. Departamento de Biología Celular e Histología, 2016) Xiao, Ke; Zhou, Ying; Yuan, Huai Rui; Cui, Lu; Rehman, Zia ur; Ansari, Abdur Rahman; Yang, Zhi; Peng, Ke Mei; Song, HuiVisfatin is an adipocytokine displaying multiple functional properties, which plays a role in the regulation of cell apoptosis and inflammation by an as yet unidentified mechanism. The aim of the present study was to determine if visfatin is involved in apoptosis pathway induced by LPS in rat Mesenteric lymph nodes (MLNs). Experimental rats were divided into four groups and MLNs samples were collected from each group. The morphological changes of the MLNs were examined by histological imaging. CD68 and ENPP1 were detected with immunohistochemistry and Western Blot. Apoptosis was evaluated with TUNEL and Flow Cytometry, the mRNA levels of the apoptosisrelated genes were detected by qRT-PCR, and the protein levels of the apoptotic-related factors were detected by western blot. The main results showed that visfatin could significantly increase the macrophages in MLNs and prevent cell apoptosis from LPS-induced mesenteric lymph nodes, activate apoptotic signaling pathways and regulate the mRNA levels of the apoptosis-related genes. Visfatin had a pro-apoptotic effect on normal MLNs, whereas it exerted an anti-apoptotic effect during LPSinduced cell apoptosis in rat MLNs. In short, visfatin plays a dual role in the apoptosis in rat MLNs, which is mediated by both the mitochondrial apoptotic pathway and the death-receptor apoptotic pathway.
- PublicationOpen AccessThe role and mechanism of PKM2 in the development of LPS-induced acute kidney injury(Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2021) Wu, Jiajun; Rong, Shu; Zhou, Jing; Yuan, WeijieA previous study suggested that pyruvate kinase M2 (PKM2) plays a vital role of metabolic reprogramming in the regulation of the innate inflammatory response, while PKM2 is a sensitive biomarker for nephrotoxicity. In this study, we investigated the role and mechanism of PKM2 in development of LPS-induced acute kidney injury. The AKI model of mice was established using LPS. The serum levels of blood urea nitrogen (Bun), creatinine (Cr), and Cystatin C (CysC) were identified using the enzyme-linked immunosorbent assay (ELISA). Hematoxylin and Eosin staining (H&E) was employed to assess pathological changes in kidney tissues of LPSinduced AKI model. Immunohistochemical staining and Western blot analysis were carried out to determine the expression of apoptosis-related factors at protein levels. We found that Bun, CysC, and Cr were significantly increased in the LPS group compared with the control group. The histopathological assay showed model swollen tubular epithelial cells and the presence of vacuolar degeneration in the LPS-induced AKI. In addition, expression levels of PKM2 significantly increased in the LPS group compared with the control group at both protein and mRNA levels (P<0.01). The inhibition of PKM2 by shikonin notably suppressed the expression of HIF-1α and apoptosis-related factors such as BNIP3, Bax, and Caspase-3, while the inhibition of PKM2 by shikonin significantly improved the histopathological symptoms of LPS-induced AKI. This study demonstrated the potential role of PKM2 in LPSinduced AKI and identified PKM2 as a promising therapeutic target in the treatment of AKI.