VEGF promotes malaria-associated acute lung injury in mice.
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ABSTRACT:
SUBMITTER: Epiphanio S
PROVIDER: S-EPMC2873913 | biostudies-other | 2010 May
REPOSITORIES: biostudies-other
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Project description:Malaria remains one of the greatest burdens to global health, causing nearly 500,000 deaths in 2014. When manifesting in the lungs, severe malaria causes acute lung injury/acute respiratory distress syndrome (ALI/ARDS). We have previously shown that a proportion of DBA/2 mice infected with Plasmodium berghei ANKA (PbA) develop ALI/ARDS and that these mice recapitulate various aspects of the human syndrome, such as pulmonary edema, hemorrhaging, pleural effusion and hypoxemia. Herein, we investigated the role of neutrophils in the pathogenesis of malaria-associated ALI/ARDS. Mice developing ALI/ARDS showed greater neutrophil accumulation in the lungs compared with mice that did not develop pulmonary complications. In addition, mice with ALI/ARDS produced more neutrophil-attracting chemokines, myeloperoxidase and reactive oxygen species. We also observed that the parasites Plasmodium falciparum and PbA induced the formation of neutrophil extracellular traps (NETs) ex vivo, which were associated with inflammation and tissue injury. The depletion of neutrophils, treatment with AMD3100 (a CXCR4 antagonist), Pulmozyme (human recombinant DNase) or Sivelestat (inhibitor of neutrophil elastase) decreased the development of malaria-associated ALI/ARDS and significantly increased mouse survival. This study implicates neutrophils and NETs in the genesis of experimentally induced malaria-associated ALI/ARDS and proposes a new therapeutic approach to improve the prognosis of severe malaria.
| S-EPMC5142790 | biostudies-literature
Project description:Although respiratory distress is a common complication of severe malaria, little is known about the underlying molecular basis of lung dysfunction. Animal models have provided powerful insights into the pathogenesis of severe malaria syndromes such as cerebral malaria; however, no model of malaria-induced lung injury has been definitively established. This work used bronchoalveolar lavage (BAL), histopathology and gene expression analysis to examine the development of acute lung injury (ALI) in mice infected with Plasmodium berghei ANKA (PbA). BAL fluid of PbA-infected C57BL/6 mice revealed a significant increase in IgM and total protein prior to the development of cerebral malaria (CM), indicating disruption of the alveolar-capillary membrane barrier â the physiological hallmark of acute lung injury (ALI). In contrast to sepsis-induced ALI, BAL fluid cell counts remained constant with no infiltration of neutrophils. Histopathology showed septal inflammation without cellular transmigration into the alveolar spaces. Microarray analysis comparing malaria-induced ALI with sepsis-induced ALI identified several common gene ontology groups characterizing ALI in these models, including defense and immune response. Severity of malaria-induced ALI varied in a panel of inbred mouse strains, and development of ALI correlated with peripheral parasite burden but not CM susceptibility. CD36-/- mice, which have decreased parasite lung sequestration, were relatively protected from ALI. In summary, parasite burden and CD36-mediated sequestration in the lung are primary determinants of ALI in experimental murine malaria. Furthermore, differential susceptibility of mouse strains to malaria-induced ALI and CM indicate that distinct genetic determinants likely regulate susceptibility to these two important causes of malaria-associated morbidity and mortality. Keywords: Time course Lungs were excised immediately following euthanasia, snap-frozen in liquid nitrogen and stored at â80°C until use. Total RNA was extracted using Trizol reagent (Invitrogen) according to the manufacturerâs instructions, and mRNA was purified using an Oligo-dT cellulose column (NEB, Mississauga, ON) as described previously [54]. cDNA with incorporated 5-(3-aminoallyl)-2âdeoxyuridine-5â-triphosphate (AAdUTP; Sigma, Oakville ON) was reverse-transcribed from 1-2 µg mRNA. Purified cDNA was coupled with N-hydroxysuccinimide esters of Cy3 or Cy5 (GE Lifesciences, Baie d'Urfe QC). Cy3 and Cy5-labeled cDNA pairs and Agilent control spots were added to a final volume of 0.5ml hybridization buffer (1 M NaCl, 0.5% sodium sarcosine, 50 mM methyl ethane sulfonate (MES), pH 6.5, 33% formamide and 40µg salmon sperm DNA (Invitrogen)). Hybridizations were performed in Agilent hybridization (Agilent, Palo Alto CA) chambers at 42°C with rotation for 18-24 hours. Slides were washed in 6X SSPE, 0.005% sarcosine, followed by 0.06X SSPE, allowed to dry and scanned with a 4000A microarray scanner (Axon Instruments, Union City CA). TIFF images were quantified with GenePix (Axon Instruments). Variance stabilizing normalization [55] and loess smoothing were applied in Bioconductor [56] and the data were transformed to log2 scale. Each array was hybridized with cDNA transcribed from an RNA pool of 5 C57BL/6 mice per timepoint (Day 0 and 6) and technical replicates (dye-swap) experiments were performed for both time points.
2010-05-26 | E-GEOD-9497 | biostudies-arrayexpress
Project description:Severe malaria can manifest itself with a variety of well-recognized clinical phenotypes that are highly predictive of death - severe anaemia, coma (cerebral malaria), multiple organ failure, and respiratory distress. The reasons why an infected individual develops one pathology rather than another remain poorly understood. Here we use distinct rodent models of infection to show that the host microbiota is a contributing factor for the development of respiratory distress syndrome and host mortality in the context of malaria infections (malaria-associated acute respiratory distress syndrome, MA-ARDS). We show that parasite sequestration in the lung results in sustained immune activation. Subsequent production of the anti-inflammatory cytokine IL-10 by T cells compromises microbial control, leading to severe lung disease. Notably, bacterial clearance with linezolid, an antibiotic commonly used in the clinical setting to control lung-associated bacterial infections, prevents MA-ARDS-associated lethality. Thus, we propose that the host's anti-inflammatory response to limit tissue damage can result in loss of microbial control, which promotes MA-ARDS. This must be considered when intervening against life-threatening respiratory complications.
| S-EPMC9243033 | biostudies-literature
Project description:Although respiratory distress is a common complication of severe malaria, little is known about the underlying molecular basis of lung dysfunction. Animal models have provided powerful insights into the pathogenesis of severe malaria syndromes such as cerebral malaria; however, no model of malaria-induced lung injury has been definitively established. This work used bronchoalveolar lavage (BAL), histopathology and gene expression analysis to examine the development of acute lung injury (ALI) in mice infected with Plasmodium berghei ANKA (PbA). BAL fluid of PbA-infected C57BL/6 mice revealed a significant increase in IgM and total protein prior to the development of cerebral malaria (CM), indicating disruption of the alveolar-capillary membrane barrier – the physiological hallmark of acute lung injury (ALI). In contrast to sepsis-induced ALI, BAL fluid cell counts remained constant with no infiltration of neutrophils. Histopathology showed septal inflammation without cellular transmigration into the alveolar spaces. Microarray analysis comparing malaria-induced ALI with sepsis-induced ALI identified several common gene ontology groups characterizing ALI in these models, including defense and immune response. Severity of malaria-induced ALI varied in a panel of inbred mouse strains, and development of ALI correlated with peripheral parasite burden but not CM susceptibility. CD36-/- mice, which have decreased parasite lung sequestration, were relatively protected from ALI. In summary, parasite burden and CD36-mediated sequestration in the lung are primary determinants of ALI in experimental murine malaria. Furthermore, differential susceptibility of mouse strains to malaria-induced ALI and CM indicate that distinct genetic determinants likely regulate susceptibility to these two important causes of malaria-associated morbidity and mortality. Keywords: Time course
2008-01-31 | GSE9497 | GEO
Project description:BackgroundMalaria-associated acute lung injury (MA-ALI) is a well-recognized clinical complication of severe, complicated malaria that is partly driven by sequestrations of infected red blood cells (iRBCs) on lung postcapillary induced impaired blood flow. In earlier studies the mechanosensitive Piezo1 channel emerged as a regulator of mechanical stimuli, but the function and underlying mechanism of Piezo1 impacting MA-ALI severity via sensing the impaired pulmonary blood flow are still not fully elucidated. Thus, the present study aimed to explore the role of Piezo1 in the severity of murine MA-ALI.MethodsHere, we utilized a widely accepted murine model of MA-ALI using C57BL/6 mice with Plasmodium berghei ANKA infection and then added a Piezo1 inhibitor (GsMTx4) to the model. The iRBC-stimulated Raw264.7 macrophages in vitro were also targeted with GsMTx4 to further explore the potential mechanism.ResultsOur data showed an elevation in the expression of Piezo1 and number of Piezo1+-CD68+ macrophages in lung tissues of the experimental MA-ALI mice. Compared to the infected control mice, the blockage of Piezo1 with GsMTx4 dramatically improved the survival rate but decreased body weight loss, peripheral blood parasitemia/lung parasite burden, experimental cerebral malaria incidence, total protein concentrations in bronchoalveolar lavage fluid, lung wet/dry weight ratio, vascular leakage, pathological damage, apoptosis and number of CD68+ and CD86+ macrophages in lung tissues. This was accompanied by a dramatic increase in the number of CD206+ macrophages (M2-like subtype), upregulation of anti-inflammatory cytokines (e.g. IL-4 and IL-10) and downregulation of pro-inflammatory cytokines (e.g. TNF-α and IL-1β). In addition, GsMTx4 treatment remarkably decreased pulmonary intracellular iron accumulation, protein level of 4-HNE (an activator of ferroptosis) and the number of CD68+-Piezo1+ and CD68+-4-HNE+ macrophages but significantly increased protein levels of GPX4 (an inhibitor of ferroptosis) in experimental MA-ALI mice. Similarly, in vitro study showed that the administration of GsMTx4 led to a remarkable elevation in the mRNA levels of CD206, IL-4, IL-10 and GPX-4 but to a substantial decline in CD86, TNF-α, IL-1β and 4-HNE in the iRBC-stimulated Raw264.7 cells.ConclusionsOur findings indicated that blockage of Piezo1 with GsMTx4 alleviated the severity of experimental MA-ALI in mice partly by triggering pulmonary macrophage M2 polarization and subsequent anti-inflammatory responses but inhibited apoptosis and ferroptosis in lung tissue. Our data suggested that targeting Piezo1 in macrophages could be a promising therapeutic strategy for treating MA-ALI.
| S-EPMC10832208 | biostudies-literature
Project description:The acute respiratory distress syndrome (ARDS) is a major healthcare problem, accounting for significant mortality and long-term disability. Approximately 25% of patients with ARDS will develop an overexuberant fibrotic response, termed fibroproliferative ARDS (FP-ARDS) that portends a poor prognosis and increased mortality. The cellular pathological processes that drive FP-ARDS remain incompletely understood. We have previously shown that the transmembrane receptor-type tyrosine phosphatase protein tyrosine phosphatase-α (PTPα) promotes pulmonary fibrosis in preclinical murine models through regulation of transforming growth factor-β (TGF-β) signaling. In this study, we examine the role of PTPα in the pathogenesis of FP-ARDS in a preclinical murine model of acid (HCl)-induced acute lung injury. We demonstrate that although mice genetically deficient in PTPα (Ptpra-/-) are susceptible to early HCl-induced lung injury, they exhibit markedly attenuated fibroproliferative responses. In addition, early profibrotic gene expression is reduced in lung tissue after acute lung injury in Ptpra-/- mice, and stimulation of naïve lung fibroblasts with the BAL fluid from these mice results in attenuated fibrotic outcomes compared with wild-type littermate controls. Transcriptomic analyses demonstrate reduced extracellular matrix (ECM) deposition and remodeling in mice genetically deficient in PTPα. Importantly, human lung fibroblasts modified with a CRISPR-targeted deletion of PTPRA exhibit reduced expression of profibrotic genes in response to TGF-β stimulation, demonstrating the importance of PTPα in human lung fibroblasts. Together, these findings demonstrate that PTPα is a key regulator of fibroproliferative processes following acute lung injury and could serve as a therapeutic target for patients at risk for poor long-term outcomes in ARDS.
| S-EPMC9255711 | biostudies-literature
Project description:The receptor for advanced glycation end-products (RAGE) is involved in inflammatory response during acute respiratory distress syndrome (ARDS). Growing body of evidence support strategies of RAGE inhibition in experimental lung injury, but its modalities and effects remain underinvestigated. Anesthetised C57BL/6JRj mice were divided in four groups; three of them underwent orotracheal instillation of acid and were treated with anti-RAGE monoclonal antibody (mAb) or recombinant soluble RAGE (sRAGE), acting as a decoy receptor. The fourth group served as a control. Lung injury was assessed by the analysis of blood gases, alveolar permeability, histology, AFC, and cytokines. Lung expression and distribution epithelial channels ENaC, Na,K-ATPase, and aquaporin (AQP)-5 were assessed. Treatment with either anti-RAGE mAb or sRAGE improved lung injury, arterial oxygenation and decreased alveolar inflammation in acid-injured animals. Anti-RAGE therapies were associated with restored AFC and increased lung expression of AQP-5 in alveolar cell. Blocking RAGE had potential therapeutic effects in a translational mouse model of ARDS, possibly through a decrease in alveolar type 1 epithelial cell injury as shown by restored AFC and lung AQP-5 expression. Further mechanistic studies are warranted to describe intracellular pathways that may control such effects of RAGE on lung epithelial injury and repair.
| S-EPMC5543147 | biostudies-literature
Project description:BackgroundAcute lung injury/acute respiratory distress syndrome (ALI/ARDS) are clinical syndromes characterized by acute lung inflammation, pulmonary edema and hypoxemia, with up to 50% mortality rate without effective pharmacological therapy. Following the acute inflammation, repair and remodeling occurs which in some cases resulting in lung fibrosis. The pathophysiology of ALI/ARDS remains incompletely understood. Lipopolysaccharide (LPS)-induced ALI in mice have been widely used as a model to study human ALI/ARDS. Isthmin 1 (ISM1) is a secreted protein highly abundant in mouse lung. We have previously reported that upon intratracheal LPS instillation, ISM1 expression in the lung is further upregulated. Recently, we also reported that ISM1 is an anti-inflammatory protein in the lung with Ism1-/- mice presenting spontaneous chronic low-grade lung inflammation and obvious emphysema at young adult stage. However, what role ISM1 plays in ALI/ARDS and lung fibrosis remain unclear.MethodsUsing Ism1-/- mice and intratracheal LPS-induced ALI, and local delivery of recombinant ISM1 (rISM1), we investigated the role ISM1 plays in ALI and post-ALI lung fibrosis using flow cytometry, Western blot, antibody array, immunohistochemistry (IHC), immunofluorescent and other histological staining.ResultsWe reveal that ISM1 deficiency in mice led to an intensified acute lung inflammation upon intratracheal LPS challenge, with a heightened leukocyte infiltration including neutrophils and monocyte-derived alveolar macrophages, as well as upregulation of multiple pro-inflammatory cytokines/chemokines including tumor necrosis factor α (TNF-α). Although innate immune cells largely subsided to the baseline by day 7 post-LPS challenge in both wild-type and Ism1-/- mice, Ism1-/- lung showed increased post-ALI fibrosis from day 9 post-LPS treatment with increased myofibroblasts, excessive collagen accumulation and TGF-β upregulation. The heightened lung fibrosis remained on day 28 post-LPS. Moreover, intranasal delivered recombinant ISM1 (rISM1) effectively suppressed LPS-induced acute lung inflammation and ALI, and rISM1 suppressed LPS-induced NF-κB activation in cultured mouse alveolar macrophages.ConclusionTogether with our previous report, this work further established ISM1 as an endogenous anti-inflammation protein in the lung, restraining excessive host inflammatory response to LPS-triggered ALI and suppressing post-ALI lung fibrosis likely through suppressing NF-κB activation and pro-inflammatory cytokine/chemokine production.
| S-EPMC9233842 | biostudies-literature
Project description:Acute lung injury (ALI) is one of the most common clinical emergencies with limited effective pharmaceutical treatment in the clinic, especially when it progresses to acute respiratory distress syndrome (ARDS). Currently, mesenchymal stem cells (MSCs) exhibit specific superiority for ALI/ARDS treatment. However, stem cells from different sources may result in controversial effects on similar disease conditions. This study aimed to determine the effects of human amnion-derived mesenchymal stem cells (hAMSCs) on two different ALI mice model. The administered hAMSCs effectively accumulated in the lung tissues in all hAMSC-treated groups. Compared with the model and 1% human serum albumin (HSA) groups, high-dose hAMSCs (1.0 × 106 cells) group significantly alleviated alveolar-capillary permeability, oxidative stress, inflammatory factors level and histopathological damage. In addition, the NF-κB signaling pathway is one of the key pathways activated during lipopolysaccharide (LPS) or paraquat (PQ)-induced lung injury. Our results indicated that hAMSCs (1.0 × 106 cells) obviously inhibited the expression of p-IKKα/β, p-IκBα, and p-p65 in the lung tissue (p < 0.05). The high-dose (HD) hAMSC treatment exerted beneficial therapeutic effects on ALI mice models without detectable adverse reactions. The therapeutic effect of hAMSCs might involve NF-κB signaling pathway inhibition. hAMSC treatment is a potential candidate therapy for ALI.
| S-EPMC10304826 | biostudies-literature
Project description:Paraquat is a poisoning herbicide that primarily targets lung, leading to severe acute lung injury characterized by extensive neutrophil infiltration. However, the mechanisms underlying the neutrophil infiltration is not clear. In this study, we demonstrated the significance of the signaling cascade from high-mobility group box 1 (HMGB1), to Toll-like receptor 4 (TLR4), interleukin-23 (IL-23), and lastly to IL-17A during the paraquat-induced neutrophil infiltration and the subsequent lung injury in mice. Paraquat challenge significantly elevated serum levels of IL-17A and IL-23, the percentage of IL-17A-producing γδT cells in the lung, and the level of HMGB1 in bronchoalveolar lavage fluid. Reducing IL-17A production using an anti-γδT antibody, targeting IL-23 with the neutralizing antibody against IL-23p19, and blocking HMGB1 signaling by using glycyrrhizin or TLR4-/- mice all dramatically inhibited the infiltration of neutrophils and attenuated lung injury. These novel findings not only reveal the critical role of HMGB1-TLR4-IL-23-IL-17A axis in the pathogenesis of paraquat-induced acute lung injury, but also provide promising therapeutic targets for treating paraquat poisoning.
| S-EPMC5429653 | biostudies-literature