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The intestinal epithelium forms a physical barrier assembled by intercellular junctions, preventing luminal pathogens and toxins from crossing it. The integrity of tight junctions is critical for maintaining intestinal health as the breakdown of tight junction proteins leads to various disorders. Redox reactions are closely associated with energy metabolism. Understanding the regulation of tight junctions by cellular metabolism and redox status in cells may lead to the identification of potential targets for therapeutic interventions. In vitro and in vivo models have been utilized in investigating intestinal barrier dysfunction and in particular the free-living soil nematode, Caenorhabditis elegans, may be an important alternative to mammalian models because of its convenience of culture, transparent body for microscopy, short generation time, invariant cell lineage and tractable genetics.
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Enfermedades Gastrointestinales , Uniones Estrechas , Animales , Uniones Estrechas/metabolismo , Proteínas de Uniones Estrechas/metabolismo , Mucosa Intestinal/metabolismo , Intestinos , Oxidación-Reducción , Enfermedades Gastrointestinales/metabolismo , Mamíferos/metabolismoRESUMEN
When activated by thrombin, the platelets release their granular store of factors. These thrombin-activated platelets (TAPLT) have been shown to be capable of ameliorating pro-inflammatory processes. In this study, we tested if TAPLT could also protect the endothelium against tumor-related pro-inflammatory changes that promote angiogenesis and metastasis. Using endothelial cell (EC) models in vitro, we demonstrated that TAPLT protected EC against tumor conditioned medium (TCM)-induced increases of reactive oxygen species (ROS) production, EC permeability and angiogenesis, and inhibited transendothelial migration that was critical for cancer cell extravasation and metastasis. In vivo observations of TAPLT-mediated inhibition of angiogenesis and pulmonary colonization in a BALB/c nude mouse model were consistent with the in vitro findings. Neutralization of vascular cell adhesion molecule-1 (VCAM-1) binding significantly inhibited the ability of TAPLT to interact with EC and abrogated the TAPLT-mediated protection of EC against tumor angiogenesis and metastasis. Taken together, these findings suggest that VCAM-1-mediated linkage to EC is required for TAPLT to confer protection of EC against tumor-induced permeation and angiogenesis, thereby resisting tumor extravasation and metastasis.
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Endotelio Vascular , Molécula 1 de Adhesión Celular Vascular , Animales , Plaquetas/metabolismo , Adhesión Celular/fisiología , Movimiento Celular , Células Cultivadas , Selectina E/metabolismo , Endotelio Vascular/metabolismo , Ratones , Trombina/metabolismo , Trombina/farmacología , Molécula 1 de Adhesión Celular Vascular/metabolismoRESUMEN
Senescence is a state of cell cycle arrest that plays an important role in embryogenesis, wound healing and protection against cancer. Senescent cells also accumulate during aging and contribute to the development of age-related disorders and chronic diseases, such as atherosclerosis, type 2 diabetes, osteoarthritis, idiopathic pulmonary fibrosis, and liver disease. Molecules that induce apoptosis of senescent cells, such as dasatinib, quercetin, and fisetin, produce health benefits and extend lifespan in animal models. We describe here the mechanism of action of senolytics and senomorphics, many of which are derived from plants and fungi. We also discuss the possibility of using such compounds to delay aging and treat chronic diseases in humans.
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Senescencia Celular , Diabetes Mellitus Tipo 2 , Envejecimiento , Animales , Enfermedad Crónica , Humanos , LongevidadRESUMEN
OBJECTIVES: Endothelial progenitor cells (EPCs) circulate with increased numbers in the peripheral blood of patients with highly-vascularised hepatocellular carcinoma (HCC) and contribute to angiogenesis and neovascularisation. We hypothesised that angiogenic EPCs, that is, colony forming unit-endothelial cells (CFU-ECs), and outgrowth EPCs, that is, endothelial colony-forming cells, may exert paracrine effects on the behaviours and metastatic capacities of human hepatoma cells. DESIGN: Various molecular and functional approaches ranging from in vitro cell culture studies on molecular signalling to in vivo investigations on cell invasion and orthotropic transplantation models in mice and clinical specimens from patients with HCC were used. RESULTS: Monocyte chemotactic protein-1 (MCP-1) was identified as a critical mediator released from CFU-ECs to contribute to the chemotaxis of Huh7 and Hep3B cells by inducing their microRNA-21 (miR-21) biogenesis through the C-C chemokine receptor-2/c-Jun N-terminal kinase/activator protein-1 signalling cascade. CFU-EC-induction of miR-21 in these cells activated their Rac1 and matrix metallopeptidase-9 by silencing Rho GTPase-activating protein-24 and tissue inhibitor of metalloproteinase-3, respectively, leading to increased cell mobility. MCP-1-induction of miR-21 induced epithelial-mesenchymal transformation of Huh7 cells in vitro and their intrahepatic metastatic capability in vivo. Moreover, increased numbers of MCP-1(+) EPCs and their positive correlations with miR-21 induction and metastatic stages in human HCC were found. CONCLUSIONS: Our results provide new insights into the complexity of EPC-HCC interactions and indicate that anticancer therapies targeting either the MCP-1 released from angiogenic EPCs or the miR-21 biogenesis in HCC cells may prevent the malignant progression of primary tumours.
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Carcinoma Hepatocelular/patología , Carcinoma Hepatocelular/fisiopatología , Quimiocina CCL2/fisiología , Células Progenitoras Endoteliales/fisiología , Neoplasias Hepáticas/patología , Neoplasias Hepáticas/fisiopatología , MicroARNs/fisiología , Línea Celular Tumoral , Quimiotaxis/fisiología , Técnicas de Cocultivo , Humanos , Sistema de Señalización de MAP Quinasas/fisiología , Metaloproteinasa 9 de la Matriz/metabolismo , Proteína de Unión al GTP rac1/fisiologíaRESUMEN
BACKGROUND: Autoimmune hepatitis (AIH) is an immune-mediated hepatic disease associated with intense complications. AIH is more common in females and needs effective drugs to treat. Guizhi Fuling Wan (GZFLW) is a traditional Chinese herbal formula used to treat various gynecologic diseases. In this study, we aim to extend the new use of GZFLW for AIH. METHODS: The tandem MS-based analysis was used to identify secondary metabolites in GZFLW. Therapeutic effects of GZFLW were tested in a concanavalin A (Con A)-induced AIH model in mice. Ethnopharmacological mechanisms underlying the antiapoptotic, antioxidant, and immunomodulatory protective effects were determined. RESULTS: Oral administration of GZFLW attenuates AIH in a Con A-induced hepatotoxic model in vivo. The tandem MS-based analysis identified 15 secondary metabolites in GZFLW. The Con A-induced AIH syndromes, including hepatic apoptosis, inflammation, reactive oxygen species accumulation, function failure, and mortality, were significantly alleviated by GZFLW in mice. Mechanistically, GZFLW restrained the caspase-dependent apoptosis, restored the antioxidant system, and decreased pro-inflammatory cytokine production in the livers of Con A-treated mice. Besides, GZFLW repressed the Con A-induced hepatic infiltration of inflammatory cells, splenic T cell activation, and splenomegaly in mice. CONCLUSIONS: Our findings demonstrate the applicable potential of GZFLW in treating AIH. It prompts further investigation of GZFLW as a treatment option for AIH and possibly other hepatic diseases.
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Recent studies indicate that mineral nanoparticles (NPs) form spontaneously in human body fluids. These biological NPs represent mineral precursors that are associated with ectopic calcifications seen in various human diseases. However, the parameters that control the formation of mineral NPs and their possible effects on human cells remain poorly understood. Here a nanomaterial approach to study the formation of biomimetic calcium phosphate NPs comparable to their physiological counterparts is described. Particle sizing using dynamic light scattering reveals that serum and ion concentrations within the physiological range yield NPs below 100 nm in diameter. While the particles are phagocytosed by macrophages in a size-independent manner, only large particles or NP aggregates in the micrometer range induce cellular responses that include production of mitochondrial reactive oxygen species, caspase-1 activation, and secretion of interleukin-1ß (IL-1ß). A comprehensive proteomic analysis reveals that the particle-bound proteins are similar in terms of their identity and number, regardless of particle size, suggesting that protein adsorption is independent of particle size and curvature. In conclusion, the conditions underlying the formation of mineralo-protein particles are similar to the ones that form in vivo. While mineral NPs do not activate immune cells, they may become pro-inflammatory and contribute to pathological processes once they aggregate and form larger mineral particles.
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Materiales Biomiméticos/química , Líquidos Corporales/metabolismo , Calcio/química , Fenómenos Químicos , Nanopartículas/química , Proteínas/metabolismo , Adsorción , Animales , Materiales Biomiméticos/farmacología , Calcio/farmacología , Línea Celular , Humanos , Inflamación/patología , Iones , Macrófagos/efectos de los fármacos , Macrófagos/patología , Macrófagos/ultraestructura , Ratones , Nanopartículas/ultraestructura , Tamaño de la Partícula , Fagocitosis , Proteínas/química , Proteínas/farmacología , Suero , Electricidad EstáticaRESUMEN
RATIONALE: Phenotypic modulation of smooth muscle cells (SMCs), which are located in close proximity to endothelial cells (ECs), is critical in regulating vascular function. The role of flow-induced shear stress in the modulation of SMC phenotype has not been well defined. OBJECTIVE: The objective was to elucidate the role of shear stress on ECs in modulating SMC phenotype and its underlying mechanism. METHODS AND RESULTS: Application of shear stress (12 dyn/cm2) to ECs cocultured with SMCs modulated SMC phenotype from synthetic to contractile state, with upregulation of contractile markers, downregulation of proinflammatory genes, and decreased percentage of cells in the synthetic phase. Treating SMCs with media from sheared ECs induced peroxisome proliferator-activated receptor (PPAR)-alpha, -delta, and -gamma ligand binding activities; transfecting SMCs with specific small interfering (si)RNAs of PPAR-alpha and -delta, but not -gamma, inhibited shear induction of contractile markers. ECs exposed to shear stress released prostacyclin (PGI2). Transfecting ECs with PGI2 synthase-specific siRNA inhibited shear-induced activation of PPAR-alpha/delta, upregulation of contractile markers, downregulation of proinflammatory genes, and decrease in percentage of SMCs in synthetic phase. Mice with PPAR-alpha deficiency (compared with control littermates) showed altered SMC phenotype toward a synthetic state, with increased arterial contractility in response to angiotensin II. CONCLUSIONS: These results indicate that laminar shear stress induces synthetic-to-contractile phenotypic modulation in SMCs through the activation of PPAR-alpha/delta by the EC-released PGI2. Our findings provide insights into the mechanisms underlying the EC-SMC interplays and the protective homeostatic function of laminar shear stress in modulating SMC phenotype.
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Células Endoteliales/metabolismo , Epoprostenol/metabolismo , Proteínas Musculares/biosíntesis , Músculo Liso Vascular/metabolismo , PPAR alfa/metabolismo , PPAR delta/metabolismo , Comunicación Paracrina , Transducción de Señal , Vasoconstricción , Angiotensina II/metabolismo , Animales , Sitios de Unión , Proliferación Celular , Células Cultivadas , Técnicas de Cocultivo , Medios de Cultivo Condicionados/metabolismo , Homeostasis , Humanos , Mediadores de Inflamación/metabolismo , Ligandos , Masculino , Ratones , Ratones Noqueados , Proteínas de Microfilamentos/genética , Proteínas de Microfilamentos/metabolismo , Proteínas Musculares/genética , Proteínas Musculares/metabolismo , Miocitos del Músculo Liso/metabolismo , PPAR alfa/deficiencia , PPAR alfa/genética , PPAR delta/genética , Fenotipo , Regiones Promotoras Genéticas , Interferencia de ARN , Factor de Respuesta Sérica/metabolismo , Estrés Mecánico , Transcripción Genética , TransfecciónRESUMEN
BACKGROUND: The formation of dental plaque and its involvement in the pathogenesis of periodontitis is a topic of intense interest given the high prevalence of periodontitis in humans. Even though calcium-based particles play an active role in both dental plaque formation and periodontitis, few publications describe the physical-chemical properties of these particles. METHODS: Saliva samples were collected from healthy volunteers. From these samples, saliva-derived particles were isolated and stained for calcium using calcein or Fluo-4. The salivary particles were also subjected to characterization by flow cytometry and immunoblotting. Internalization of calcein-labeled salivary particles by gingival epithelial cells was visualized by confocal microscopy. RESULTS: We found that calcium-based salivary particles from healthy volunteers varied greatly in size but were enriched in particles of sizes at or greater than 1.5 µm. Immunoblotting analysis of the salivary particles identified several proteins including albumin, fetuin-A, and statherin, which have been found in calcium phosphate particles from other tissues or are known to modulate calcium homeostasis in saliva. In addition, calcium particles were internalized by both gingival epithelial cells and monocyte-derived macrophages. CONCLUSION: Salivary calcium particles were enriched in the micrometer range, internalized by gingival epithelial cells, and contain albumin, fetuin-A and statherin, regulators of particle formation. These characteristics of the calcium-based salivary particles and their biological activities provide a basis for further studies to understand the molecular basis for pathogenesis of periodontitis.
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Calcio , Periodontitis , Calcio/análisis , Calcio/metabolismo , Epitelio/metabolismo , Encía/metabolismo , Encía/patología , Humanos , Saliva/químicaRESUMEN
Caloric restriction (CR) mimetics are molecules that produce beneficial effects on health and longevity in model organisms and humans, without the challenges of maintaining a CR diet. Conventional CR mimetics such as metformin, rapamycin and spermidine activate autophagy, leading to recycling of cellular components and improvement of physiological function. We review here novel CR mimetics and anti-aging compounds, such as 4,4'-dimethoxychalcone, fungal polysaccharides, inorganic nitrate, and trientine, highlighting their possible molecular targets and mechanisms of action. The activity of these compounds can be understood within the context of hormesis, a biphasic dose response that involves beneficial effects at low or moderate doses and toxic effects at high doses. The concept of hormesis has widespread implications for the identification of CR mimetics in experimental assays, testing in clinical trials, and use in healthy humans. We also discuss the promises and limitations of CR mimetics and anti-aging molecules for delaying aging and treating chronic diseases.
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Envejecimiento , Restricción Calórica , Autofagia , Hormesis , Humanos , LongevidadRESUMEN
The medicinal fungus Ganoderma lucidum is used as a dietary supplement and health tonic, but whether it affects longevity remains unclear. We show here that a water extract of G. lucidum mycelium extends lifespan of the nematode Caenorhabditis elegans. The G. lucidum extract reduces the level of fibrillarin (FIB-1), a nucleolar protein that correlates inversely with longevity in various organisms. Furthermore, G. lucidum treatment increases expression of the autophagosomal protein marker LGG-1, and lifespan extension is abrogated in mutant C. elegans strains that lack atg-18, daf-16, or sir-2.1, indicating that autophagy and stress resistance pathways are required to extend lifespan. In cultured human cells, G. lucidum increases concentrations of the LGG-1 ortholog LC3 and reduces levels of phosphorylated mTOR, a known inhibitor of autophagy. Notably, low molecular weight compounds (<10 kDa) isolated from the G. lucidum water extract prolong lifespan of C. elegans and the same compounds induce autophagy in human cells. These results suggest that G. lucidum can increase longevity by inducing autophagy and stress resistance.
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Autofagia , Caenorhabditis elegans/citología , Caenorhabditis elegans/fisiología , Longevidad/fisiología , Reishi/química , Animales , Proteínas de Caenorhabditis elegans/metabolismo , Línea Celular Tumoral , Humanos , Transducción de Señal , Serina-Treonina Quinasas TOR/metabolismoRESUMEN
Vascular endothelial (VE)-cadherin is localized to the endothelial borders and the adherens junctions, which are regulated by changes in mitogen-activated protein (MAP) kinases, GTPases, and intracellular calcium. We previously showed that melanoma cells induce VE-cadherin disassembly through contact with human umbilical vein endothelial cells in coculture. However, the exact mechanism by which melanoma cells signal endothelial cells to induce VE-cadherin junction disassembly is not well understood. In this study, VE-cadherin junction disassembly was further examined under fluorescence microscopy. We found that melanoma-induced VE-cadherin junction disassembly and upregulation of p38 MAP kinase in endothelial cells is regulated by both soluble factors from melanomas, particularly interleukin (IL)-8, IL-6, and IL-1beta, and through vascular cell adhesion molecule-1. Neutralizing melanoma-secreted soluble factors reduced endothelial gap formation. Endothelial cells transfected with MAP kinase kinase 6, a direct activator of p38 MAP kinase, increased VE-cadherin-mediated gap formation, facilitating melanoma transendothelial migration. In contrast, endothelial cells transfected with small-interfering RNA against p38 MAP kinase expression largely prevented melanoma transendothelial migration in Boyden chamber experiments. These findings indicate that p38 MAP kinase proteins regulate VE-cadherin junction disassembly, facilitating melanoma migration across endothelial cells.
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Antígenos CD/metabolismo , Cadherinas/metabolismo , Citocinas/metabolismo , Melanoma/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo , Antígenos CD/genética , Cadherinas/genética , Línea Celular Tumoral , Movimiento Celular , Regulación Enzimológica de la Expresión Génica , Regulación Neoplásica de la Expresión Génica/fisiología , Humanos , Molécula 1 de Adhesión Celular Vascular/metabolismoRESUMEN
The nematode Caenorhabditis elegans is a useful model to study aging due to its short lifespan, ease of manipulation, and available genetic tools. Several molecules and extracts derived from plants and fungi extend the lifespan of C. elegans by modulating aging-related pathways that are conserved in more complex organisms. Modulation of aging pathways leads to activation of autophagy, mitochondrial biogenesis and expression of antioxidant and detoxifying enzymes in a manner similar to caloric restriction. Low and moderate concentrations of plant and fungal molecules usually extend lifespan, while high concentrations are detrimental, consistent with a lifespan-modulating mechanism involving hormesis. We review here molecules and extracts derived from plants and fungi that extend the lifespan of C. elegans, and explore the possibility that these natural substances may produce health benefits in humans.
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Polymorphonuclear neutrophils (PMN) facilitate melanoma cell extravasation under dynamic flow conditions by the binding of intercellular adhesion molecule-1 (ICAM-1) on melanoma cells to beta2 integrins on PMNs, which is mediated by endogenously produced chemokine interleukin 8 (IL-8) from the tumor microenvironment. However, little is known about the role of B-Raf, the most mutated gene in malignant melanomas, in this process. In this study, we investigated the functional importance of B-Raf in melanoma extravasation by using short interfering RNA to reduce expression/activity of mutant (V600E)B-Raf in melanoma. Results indicated that knockdown of mutant (V600E)B-Raf inhibited melanoma cell extravasation in vitro and subsequent lung metastasis development in vivo. Mechanistic studies showed that inhibition of (V600E)B-Raf significantly reduced the constitutive secretion of IL-8 from melanoma cells as well as the capacity of endogenous IL-8 production from the melanoma-PMN microenvironment. Furthermore, a reduction in ICAM-1 expression on melanoma cells was detected following mutant (V600E)B-Raf knockdown. Together, these results suggest that targeting mutant (V600E)B-Raf reduces melanoma cell extravasation by decreasing IL-8 production and interrupting ICAM-1-beta2 integrin binding of melanoma cells to the endothelium mediated by PMNs in the microcirculation, which provides a rationale and mechanistic basis for targeting mutant (V600E)B-Raf to inhibit melanoma extravasation and subsequent metastasis development.
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Movimiento Celular/fisiología , Melanoma Experimental/patología , Invasividad Neoplásica/patología , Neutrófilos/metabolismo , Proteínas Proto-Oncogénicas B-raf/metabolismo , Animales , Línea Celular Tumoral , Ensayo de Cambio de Movilidad Electroforética , Endotelio/metabolismo , Humanos , Molécula 1 de Adhesión Intercelular/metabolismo , Interleucina-8/metabolismo , Neoplasias Pulmonares/secundario , Ratones , Ratones Desnudos , Mutación , Trasplante de Neoplasias , Proteínas Proto-Oncogénicas B-raf/genética , ARN Interferente PequeñoRESUMEN
Caloric restriction, intermittent fasting, and exercise activate defensive cellular responses such as autophagy, DNA repair, and the induction of antioxidant enzymes. These processes improve health and longevity by protecting cells and organs against damage, mutations, and reactive oxygen species. Consuming a diet rich in vegetables, fruits, and mushrooms can also improve health and longevity. Phytochemicals such as alkaloids, polyphenols, and terpenoids found in plants and fungi activate the same cellular processes as caloric restriction, fasting, and exercise. Many of the beneficial effects of fruits and vegetables may thus be due to activation of stress resistance pathways by phytochemicals. A better understanding of the mechanisms of action of phytochemicals may provide important insights to delay aging and prevent chronic diseases.
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Fitoquímicos , Envejecimiento/fisiología , Restricción Calórica , Suplementos Dietéticos , Hormesis/fisiología , Humanos , Longevidad/fisiologíaRESUMEN
OBJECTIVES: This study aimed to evaluate the clinical and histopathologic features of gingival lesions containing foreign material (GLFMs). In parallel, the composition of the foreign material and its effects in primary human gingival fibroblasts (HGFs) were investigated. STUDY DESIGN: Eighty-six GLFMs were retrieved from an oral pathology biopsy service. Clinical and microscopic data were analyzed, and the composition of the particles was identified by using energy-dispersive X-ray spectroscopy (EDX). Furthermore, HGFs were stimulated with silica (SiO2) microparticles to investigate the production of collagen type 1 (COL-1), matrix metalloproteinase 2 (MMP2), and inflammatory cytokines. RESULTS: GLFMs were most commonly found in women (60.5%) and most frequently described as white plaques. Histopathologic examination identified verrucous hyperplasia in 59% and epithelial dysplasia in 28% of the cases. EDX microanalysis revealed that Si (94%) was the most frequently detected foreign element. SiO2 microparticles induced higher COL-1 expression; higher levels of proinflammatory cytokines, such as interleukin-6 (IL-6), IL-8, and transforming growth factor-ß, and increased MMP-2 activity in HGFs. CONCLUSIONS: There was a strong association between the presence of foreign material in the gingiva and white verrucous clinical lesions. In addition, the most common element in the foreign material was Si, and our in vitro findings demonstrate the importance of silica-mediated effects on gingival fibroblasts.
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Encía , Células Cultivadas , Femenino , Fibroblastos , Humanos , Interleucina-6 , Masculino , Metaloproteinasa 2 de la Matriz , Dióxido de SilicioRESUMEN
We observed earlier that mineralo-organic nanoparticles form in human body fluids when the concentrations of calcium, carbonate and phosphate exceed saturation. The particles have been shown to represent mineral precursors in developing bones and teeth as well as in ectopic calcification and kidney stones. Recent studies suggest that the mineral particles may also be involved in other physiological processes, including immune tolerance against the gut microbiota and food antigens. We review here the involvement of mineralo-organic nanoparticles in physiological and pathological processes and discuss recent findings that reveal novel and unexpected roles for these particles in the human body.
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CCL5/RANTES, a chemoattractant for myeloid cells, is induced by hepatic ischemia/reperfusion injury (IRI). The roles of CCL5 in hepatic IRI were carried out by means of CCL5 immunodepletion, antagonistic competition by Met-CCL5, and treatment with recombinant murine CCL5 (rmCCL5). Depletion or inhibition of CCL5 reduced severity of hepatic IRI, whereas rmCCL5 treatment aggravated liver IRI as manifested in elevated serum alanine aminotransferase (ALT) and tissue myeloperoxidase (MPO) levels. Moreover, IRI severity was reduced in CCL5-knockout (CCL5-KO) mice versus wildtype (WT) mice, with drops in serum ALT level, intrahepatic MPO activity, and histological pathology. Bone marrow transplantion (BMT) studies show that myeloid cells and tissue cells are both required for CCL5-aggravated hepatic IRI. The profile of liver-infiltrating leukocyte subsets after hepatic reperfusion identified CD11b+ cells as the only compartment significantly reduced in CCL5-KO mice versus WT controls at early reperfusion phase. The role of CCL5 recruiting CD11b+ cells in early reperfusion was validated by in vitro transwell migration assay of murine primary macrophages (broadly characterized by their CD11b expression) in response to liver lysates after early reperfusion. Taken together, our results demonstrate a sequence of early events elicited by CCL5 chemoattracting macrophage that result in inflammatory aggravation of hepatic IRI.
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Quimiocina CCL5/genética , Insuficiencia Hepática/etiología , Insuficiencia Hepática/metabolismo , Isquemia/metabolismo , Macrófagos/metabolismo , Daño por Reperfusión/etiología , Daño por Reperfusión/metabolismo , Animales , Biomarcadores , Antagonistas de los Receptores CCR5/farmacología , Proliferación Celular , Quimiocina CCL5/metabolismo , Modelos Animales de Enfermedad , Citometría de Flujo , Insuficiencia Hepática/tratamiento farmacológico , Insuficiencia Hepática/patología , Inmunohistoquímica , Inmunofenotipificación , Pruebas de Función Hepática , Macrófagos/inmunología , Macrófagos/patología , Masculino , Ratones , Ratones Noqueados , Receptores CCR5/genética , Receptores CCR5/metabolismo , Daño por Reperfusión/tratamiento farmacológico , Daño por Reperfusión/patologíaRESUMEN
Calcium phosphate-based mineralo-organic particles form spontaneously in the body and may represent precursors of ectopic calcification. We have shown earlier that these particles induce activation of caspase-1 and secretion of IL-1ß by macrophages. However, whether the particles may produce other effects on immune cells is unclear. Here, we show that these particles induce the release of neutrophil extracellular traps (NETs) in a size-dependent manner by human neutrophils. Intracellular production of reactive oxygen species is required for particle-induced NET release by neutrophils. NETs contain the high-mobility group protein B1 (HMGB1), a DNA-binding protein capable of inducing secretion of TNF-α by a monocyte/macrophage cell line and primary macrophages. HMGB1 functions as a ligand of Toll-like receptors 2 and 4 on macrophages, leading to activation of the MyD88 pathway and TNF-α production. Furthermore, HMGB1 is critical to activate the particle-induced pro-inflammatory cascade in the peritoneum of mice. These results indicate that mineral particles promote pro-inflammatory responses by engaging neutrophils and macrophages via signaling of danger signals through NETs.
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Trampas Extracelulares/inmunología , Proteína HMGB1/metabolismo , Inmunidad Innata , Inmunomodulación , Minerales/inmunología , Neutrófilos/inmunología , Neutrófilos/metabolismo , Animales , Línea Celular , Femenino , Proteína HMGB1/genética , Humanos , Activación de Macrófagos , Macrófagos/inmunología , Macrófagos/metabolismo , Masculino , Ratones , Modelos Moleculares , Factor 88 de Diferenciación Mieloide/metabolismo , Especies Reactivas de Oxígeno , Transducción de Señal , Receptor Toll-Like 2/metabolismo , Receptor Toll-Like 4/metabolismo , Factor de Necrosis Tumoral alfa/biosíntesisRESUMEN
In this study, we report a phospholipase C (PLC)-mediated mechanism for the redistribution of interendothelial adherens junctions in response to melanoma cell contacts with the endothelium. We demonstrated that contact of melanoma cells to human umbilical vein endothelial cells (HUVEC) triggered rapid endothelial [Ca2+]i response through PLC-IP3 pathway. In addition, alternation of endothelial adherens junctions following contact of melanoma cells was evidenced by the changes in immunological staining patterns of vascular endothelial (VE)-cadherin. A PLC inhibitor, U73122 was shown to significantly diminish [Ca2+]i response and reduce the occurrence of melanoma cell-induced VE-cadherin reorganization. Moreover, inhibition of PLC attenuated melanoma cell transendothelial migration. However, melanoma cell-associated VE-cadherin breakdown was not sensitive to Ly294002, an inhibitor of phosphatidylinositol-3-kinase (PI3K), whereas inhibition of PI3K resulted in a reduction of melanoma cell transmigration. Taken together, our findings implicate that by inducing the PLC-Ca2+ signaling pathway, melanoma cells disrupt EC junctions to breach the endothelium and promote transvascular homing of tumor cells.
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Endotelio Vascular/metabolismo , Uniones Intercelulares/patología , Melanoma/patología , Transducción de Señal/fisiología , Fosfolipasas de Tipo C/fisiología , Antígenos CD , Cadherinas/metabolismo , Calcio/metabolismo , Movimiento Celular/fisiología , Endotelio Vascular/patología , Humanos , Fosfatidilinositol 3-Quinasas/metabolismo , Células Tumorales CultivadasRESUMEN
AIMS: Mineralo-organic nanoparticles (NPs) detected in biological fluids have been described as precursors of physiological and pathological calcifications in the body. Our main objective was to examine the early stages of mineral NP formation in body fluids. MATERIALS & METHODS: A nanomaterial approach based on atomic force microscopy, dynamic light scattering, electron microscopy and spectroscopy was used. RESULTS: The mineral particles, which contain the serum proteins albumin and fetuin-A, initially precipitate in the form of round amorphous NPs that gradually grow in size, aggregate and coalesce to form crystalline mineral films similar to the structures observed in calcified human arteries. CONCLUSION: Our study reveals the early stages of particle formation and provides a platform to analyze the role(s) of mineralo-organic NPs in human tissues.