50 research outputs found

    Current Status of Stem Cell Therapy for Sepsis and Acute Respiratory Distress Syndrome

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    Sepsis and acute respiratory distress syndrome (ARDS) are life-threatening diseases with high mortality, around 40%, and morbidity in all the critical care units around the world. After decades of research, and numerous pre-clinical and clinical trials, sepsis and ARDS remain without a specific and effective pharmacotherapy and essentially the management remains supportive. Over the last years, cell therapies gained potential as a therapeutic treatment for ARDS and sepsis. Based on numerous pre-clinical studies, there is a growing evidence of the potential benefits of cell-based therapies for the treatment of sepsis and ARDS. Different cell subtypes have been used for the treatment of both syndromes; however, the major part of the studies is using mesenchymal stem/stromal cells (MSC). Also, other relevant groups performed some pre-clinical studies using induced pluripotent stem cells (iPSC) for the treatment of both syndromes and alveolar type II cells for ARDS treatment. Numerous questions need further study, including determining the best source for the progenitor cells isolation, their large-scale production, and cryopreservation. Also, the heterogeneity of patients with sepsis and ARDS is massive, and the stratification of the patients will help us to determine better the therapeutic effect of these cell therapies. In this review, we are going to describe briefly the different cell types, their potential sources, and characteristics and mechanism of action. We will review several pre-clinical and clinical studies in ARDS and sepsis

    Role of Mesenchymal Stem/Stromal Cells in Coagulation

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    This study was funded by Instituto de Salud Carlos III through the Miguel Servet, contract "CP20/00133 (ISCIII-AES-2019/002067) "and co-funded by the European Regional Development Fund/European Social Fund "A way to make Europe"/"Investing in your future".Mesenchymal stem/stromal cells (MSCs) are widely used in disease models in order to control several phases in the response to injuries, immune reaction, wound healing, and regeneration. MSCs can act upon both the innate and adaptive immune systems and target a broad number of functions, such as the secretion of cytokines, proteolytic enzymes, angiogenic factors, and the regulating of cell proliferation and survival. The role of MSCs in coagulation has been less studied. This review evaluates the properties and main functions of MSCs in coagulation. MSCs can regulate coagulation in a wide range of pathways. MSCs express and release tissue factors (TF), one of the key regulators of the extrinsic coagulation pathways; MSCs can trigger platelet production and contribute to platelet activation. Altogether, MSCs seem to have a pro-thrombotic role and their superior characterization prior to their administration is necessary in order to prevent adverse coagulation events

    Novel experimental model of maintained acute lung injury

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    Trabajo presentado en el 23rd Annual Congress European Respiratory Society (ERS) celebrado del 7 al 11 de septiembre de 2013 en Barcelona (España)Abstract publicado en "European Respiratory Journal" 42 (Suppl 57): 50s-51s (2013)Rationale: Several animal models have been developed to study acute lung injury (ALI); however the majority of these studies are focused on different mechanisms within the acute phase. These models do not allow studying the mechanisms in the later phases or testing any possible long-term treatment. The aim of this study was to develop an experimental ALI model simulating bronchial aspiration of gastric contents with bacterial superinfection with alveolar epithelial damage persisting over time. Methods: Sprague-Dawley rats (200-250g) were anesthetized with isofl uorane. ALI was induced by intratracheal instillation of HCl (1 μl/g, 0.1 mol/L pH=1.4) followed by instillation of LPS from Escherichia coli O55:B5 (0, 10, 20, 30 or 40μg/g b.w.) two hours later. Control rats were treated with intratracheal instillations of saline. After 72h, the animals were sacrifi ced and bronchoalveolar lavage fl uid (BALF) was sampled for further analysis of total protein concentration by bicinchoninic acid method. Results: At 72 h, rats suffered a signifi cant loss of weight proportional to the administered dose of LPS (5.6% with 10μg/g b.w, 12.6% with 20μg/g b.w, 14.2% with 30μg/g b.w and 17.7% with 40μg/g b.w). Control rats gained in weight at 72h. LPS at 10, 20, 30 and 40μg/g b.w induced a 1.7, 2.5, 2.9 and 3.4 fold increase in total protein concentration in BAL fl uid, respectively, refl ecting a substantial increase proportional to the LPS dose. Conclusion: The degree of weight loss and the increase of total protein concentration in BAL fl uid in the current model may refl ect disease severity and progression. This model would be useful in future for new therapeutical optionsGrant acknowledgements: FIS-PI12/02548 and Fundació Parc TaulíPeer Reviewe

    Nebulized Heparin Attenuates Pulmonary Coagulopathy and Inflammation through Alveolar Macrophages in a Rat Model of Acute Lung Injury

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    Objective Alveolar macrophages play a key role in the development and resolution of acute respiratory distress syndrome (ARDS), modulating the inflammatory response and the coagulation cascade in lungs. Anti-coagulants may be helpful in the treatment of ARDS. This study investigated the effects of nebulized heparin on the role of alveolar macrophages in limiting lung coagulation and inflammatory response in an animal model of acute lung injury (ALI). Methods Rats were randomized to four experimental groups. In three groups, ALI was induced by intratracheal instillation of lipopolysaccharide (LPS) and heparin was nebulized at constant oxygen flow: the LPS/Hep group received nebulized heparin 4 and 8 hours after injury; the Hep/LPS/Hep group received nebulized heparin 30 minutes before and 4 and 8 hours after LPS-induced injury; the LPS/Sal group received nebulized saline 4 and 8 hours after injury. The control group received only saline. Animals were exsanguinated 24 hours after LPS instillation. Lung tissue, bronchoalveolar lavage fluid (BALF) and alveolar macrophages isolated from BALF were analysed. Results LPS increased protein concentration, oedema and neutrophils in BALF as well as procoagulant and proinflammatory mediators in lung tissue and alveolar macrophages. In lung tissue, nebulized heparin attenuated ALI through decreasing procoagulant (tissue factor, thrombin-anti-thrombin complexes, fibrin degradation products) and proinflammatory (interleukin 6, tumour necrosis factor alpha) pathways. In alveolar macrophages, nebulized heparin reduced expression of procoagulant genes and the effectors of transforming growth factor beta (Smad 2, Smad 3) and nuclear factor kappa B (p-selectin, CCL-2). Pre-treatment resulted in more pronounced attenuation. Conclusion Nebulized heparin reduced pulmonary coagulopathy and inflammation without producing systemic bleeding, partly by modulating alveolar macrophages

    Comparison of direct and indirect models of early induced acute lung injury

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    The animal experimental counterpart of human acute respiratory distress syndrome (ARDS) is acute lung injury (ALI). Most models of ALI involve reproducing the clinical risk factors associated with human ARDS, such as sepsis or acid aspiration; however, none of these models fully replicates human ARDS. To compare different experimental animal models of ALI, based on direct or indirect mechanisms of lung injury, to characterize a model which more closely could reproduce the acute phase of human ARDS. Adult male Sprague-Dawley rats were subjected to intratracheal instillations of (1) HCl to mimic aspiration of gastric contents; (2) lipopolysaccharide (LPS) to mimic bacterial infection; (3) HCl followed by LPS to mimic aspiration of gastric contents with bacterial superinfection; or (4) cecal ligation and puncture (CLP) to induce peritonitis and mimic sepsis. Rats were sacrificed 24 h after instillations or 24 h after CLP. At 24 h, rats instilled with LPS or HCl-LPS had increased lung permeability, alveolar neutrophilic recruitment and inflammatory markers (GRO/KC, TNF-α, MCP-1, IL-1β, IL-6). Rats receiving only HCl or subjected to CLP had no evidence of lung injury. Rat models of ALI induced directly by LPS or HCl-LPS more closely reproduced the acute phase of human ARDS than the CLP model of indirectly induced ALI

    Palmitoylethanolamide Promotes a Proresolving Macrophage Phenotype and Attenuates Atherosclerotic Plaque Formation

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    Objective Palmitoylethanolamide is an endogenous fatty acid mediator that is synthetized from membrane phospholipids by N-acyl phosphatidylethanolamine phospholipase D. Its biological actions are primarily mediated by PPAR- (peroxisome proliferator-activated receptors ) and the orphan receptor GPR55. Palmitoylethanolamide exerts potent anti-inflammatory actions but its physiological role and promise as a therapeutic agent in chronic arterial inflammation, such as atherosclerosis remain unexplored. Approach and Results First, the polarization of mouse primary macrophages towards a proinflammatory phenotype was found to reduce N-acyl phosphatidylethanolamine phospholipase D expression and palmitoylethanolamide bioavailability. N-acyl phosphatidylethanolamine phospholipase D expression was progressively downregulated in the aorta of apolipoprotein E deficient (ApoE(-/-)) mice during atherogenesis. N-acyl phosphatidylethanolamine phospholipase D mRNA levels were also downregulated in unstable human plaques and they positively associated with smooth muscle cell markers and negatively with macrophage markers. Second, ApoE(-/-) mice were fed a high-fat diet for 4 or 16 weeks and treated with either vehicle or palmitoylethanolamide (3 mg/kg per day, 4 weeks) to study the effects of palmitoylethanolamide on early established and pre-established atherosclerosis. Palmitoylethanolamide treatment reduced plaque size in early atherosclerosis, whereas in pre-established atherosclerosis, palmitoylethanolamide promoted signs of plaque stability as evidenced by reduced macrophage accumulation and necrotic core size, increased collagen deposition and downregulation of M1-type macrophage markers. Mechanistically, we found that palmitoylethanolamide, by activating GPR55, increases the expression of the phagocytosis receptor MerTK (proto-oncogene tyrosine-protein kinase MER) and enhances macrophage efferocytosis, indicative of proresolving properties. Conclusions The present study demonstrates that palmitoylethanolamide protects against atherosclerosis by promoting an anti-inflammatory and proresolving phenotype of lesional macrophages, representing a new therapeutic approach to resolve arterial inflammation

    GPR55 in B cells limits atherosclerosis development and regulates plasma cell maturation

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    Dissecting the pathways regulating the adaptive immune response in atherosclerosis is of particular therapeutic interest. Here we report that the lipid G-protein-coupled receptor GPR55 is highly expressed by splenic plasma cells (PCs), upregulated in mouse spleens during atherogenesis and human unstable or ruptured compared to stable plaques. Gpr55-deficient mice developed larger atherosclerotic plaques with increased necrotic core size compared to their corresponding controls. Lack of GPR55 hyperactivated B cells, disturbed PC maturation and resulted in IgG overproduction. B-cell-specific Gpr55 depletion or adoptive transfer of Gpr55-deficient B cells was sufficient to promote plaque development and elevated IgG titers. In vitro, the endogenous GPR55 ligand lysophsophatidylinositol (LPI) enhanced PC proliferation, whereas GPR55 antagonism blocked PC maturation and increased their mitochondrial content. Collectively, these discoveries provide previously undefined evidence for GPR55 in B cells as a key modulator of the adaptive immune response in atherosclerosis. Using various mouse models, human plaque data and isolated B cells combined with state-of-the-art imaging and transcriptomic analysis, the authors show that the G-protein-coupled orphan receptor GPR55 regulates B cell activation and plasma cell differentiation during hypercholesterolemia, which crucially affects atherosclerosis

    Local amplifiers of IL-4Rα-mediated macrophage activation promote repair in lung and liver

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    The type 2 immune response controls helminth infection and maintains tissue homeostasis but can lead to allergy and fibrosis if not adequately regulated. We have discovered local tissue-specific amplifiers of type 2-mediated macrophage activation. In the lung, surfactant protein A (SP-A) enhanced interleukin-4 (IL-4)-dependent macrophage proliferation and activation, accelerating parasite clearance and reducing pulmonary injury after infection with a lung-migrating helminth. In the peritoneal cavity and liver, C1q enhancement of type 2 macrophage activation was required for liver repair after bacterial infection, but resulted in fibrosis after peritoneal dialysis. IL-4 drives production of these structurally related defense collagens, SP-A and C1q, and the expression of their receptor, myosin 18A. These findings reveal the existence within different tissues of an amplification system needed for local type 2 responses

    Role of Mesenchymal Stem/Stromal Cells in Coagulation

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    Mesenchymal stem/stromal cells (MSCs) are widely used in disease models in order to control several phases in the response to injuries, immune reaction, wound healing, and regeneration. MSCs can act upon both the innate and adaptive immune systems and target a broad number of functions, such as the secretion of cytokines, proteolytic enzymes, angiogenic factors, and the regulating of cell proliferation and survival. The role of MSCs in coagulation has been less studied. This review evaluates the properties and main functions of MSCs in coagulation. MSCs can regulate coagulation in a wide range of pathways. MSCs express and release tissue factors (TF), one of the key regulators of the extrinsic coagulation pathways; MSCs can trigger platelet production and contribute to platelet activation. Altogether, MSCs seem to have a pro-thrombotic role and their superior characterization prior to their administration is necessary in order to prevent adverse coagulation events
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