Effective in vivo treatment of acute lung injury with helical, amphipathic peptoid mimics of pulmonary surfactant proteins

Previous in vitro studies have suggested that surfactant protein A (SP-A) may play a role in pulmonary surfactant homeostasis by mediating surfactant secretion and clearance. However, mice made deficient in SP-A [SP-A (−/−) animals] have relatively normal levels of surfactant compared with wild-type SP-A (+/+) animals. We hypothesize that SP-A may play a role in surfactant homeostasis after acute lung injury. Bacterial lipopolysaccharide was instilled into the lungs of SP-A (−/−) mice and SP-A (+/+) mice to induce injury. Surfactant phospholipid levels were increased 1.6-fold in injured SP-A (−/−) animals, although injury did not alter [3H]choline or [14C]palmitate incorporation into dipalmitoylphosphatidylcholine (DPPC), suggesting no change in surfactant synthesis/secretion 12 h after injury. Clearance of [3H]DPPC from the lungs of injured SP-A (−/−) animals was decreased by ∼40%. Instillation of 50 μg of exogenous SP-A rescued both the clearance defect and the increased phospholipid defect in injured SP-A (−/−) animals, suggesting that SP-A may play a role in regulating clearance of surfactant phospholipids after acute lung injury.

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Role of Tilianin against Acute Lung Injury in In Vitro LPS-Induced Alveolar Macrophage Cells and an In Vivo C57BL/6 Mice Model

Journal of Environmental Pathology Toxicology and Oncology ◽

10.1615/jenvironpatholtoxicoloncol.2020035136 ◽

2020 ◽

Vol 39 (4) ◽

pp. 335-344

Author(s):

Yonghong Zhang ◽

Zhenshuai Fu

Keyword(s):

Acute Lung Injury ◽

Lung Injury ◽

Alveolar Macrophage ◽

Mice Model ◽

Macrophage Cells

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In vitro and in vivo assessment of the protective effect of sufentanil in acute lung injury

Journal of International Medical Research ◽

10.1177/0300060520986351 ◽

2021 ◽

Vol 49 (2) ◽

pp. 030006052098635

Author(s):

Qi Gao ◽

Ningqing Chang ◽

Donglian Liu

Keyword(s):

Acute Lung Injury ◽

Lung Injury ◽

Protective Effect ◽

High Mobility ◽

Terminal Deoxynucleotidyl Transferase ◽

Inflammatory Factors ◽

Luciferase Reporter ◽

Hmgb1 Protein

Objectives To investigate the mechanisms underlying the protective effect of sufentanil against acute lung injury (ALI). Material and Methods Rats were administered lipopolysaccharide (LPS) by endotracheal instillation to establish a model of ALI. LPS was used to stimulate BEAS-2B cells. The targets and promoter activities of IκB were assessed using a luciferase reporter assay. Apoptosis of BEAS-2B cells was evaluated by terminal deoxynucleotidyl transferase dUTP nick end labeling. Results Sufentanil treatment markedly reduced pathological changes in lung tissue, pulmonary edema and secretion of inflammatory factors associated with ALI in vivo and in vitro. In addition, sufentanil suppressed apoptosis induced by LPS and activated NF-κB both in vivo and in vitro. Furthermore, upregulation of high mobility group box protein 1 (HMGB1) protein levels and downregulation of miR-129-5p levels were observed in vivo and in vitro following sufentanil treatment. miR-129-5p targeted the 3ʹ untranslated region and its inhibition decreased promoter activities of IκB-α. miR-129-5p inhibition significantly weakened the protective effect of sufentanil on LPS-treated BEAS-2B cells. Conclusion Sufentanil regulated the miR-129-5p/HMGB1 axis to enhance IκB-α expression, suggesting that sufentanil represents a candidate drug for ALI protection and providing avenues for clinical treatment.

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Group V Phospholipase A2 Mediates Endothelial Dysfunction and Acute Lung Injury Caused by Methicillin-Resistant Staphylococcus aureus

Cells ◽

10.3390/cells10071731 ◽

2021 ◽

Vol 10 (7) ◽

pp. 1731

Author(s):

Yu Maw Htwe ◽

Huashan Wang ◽

Patrick Belvitch ◽

Lucille Meliton ◽

Mounica Bandela ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Acute Lung Injury ◽

Endothelial Dysfunction ◽

Lung Injury ◽

Phospholipase A2 ◽

Methicillin Resistant Staphylococcus Aureus ◽

Group V ◽

Methicillin Resistant

Lung endothelial dysfunction is a key feature of acute lung injury (ALI) and clinical acute respiratory distress syndrome (ARDS). Previous studies have identified the lipid-generating enzyme, group V phospholipase A2 (gVPLA2), as a mediator of lung endothelial barrier disruption and inflammation. The current study aimed to determine the role of gVPLA2 in mediating lung endothelial responses to methicillin-resistant Staphylococcus aureus (MRSA, USA300 strain), a major cause of ALI/ARDS. In vitro studies assessed the effects of gVPLA2 inhibition on lung endothelial cell (EC) permeability after exposure to heat-killed (HK) MRSA. In vivo studies assessed the effects of intratracheal live or HK-MRSA on multiple indices of ALI in wild-type (WT) and gVPLA2-deficient (KO) mice. In vitro, HK-MRSA increased gVPLA2 expression and permeability in human lung EC. Inhibition of gVPLA2 with either the PLA2 inhibitor, LY311727, or with a specific monoclonal antibody, attenuated the barrier disruption caused by HK-MRSA. LY311727 also reduced HK-MRSA-induced permeability in mouse lung EC isolated from WT but not gVPLA2-KO mice. In vivo, live MRSA caused significantly less ALI in gVPLA2 KO mice compared to WT, findings confirmed by intravital microscopy assessment in HK-MRSA-treated mice. After targeted delivery of gVPLA2 plasmid to lung endothelium using ACE antibody-conjugated liposomes, MRSA-induced ALI was significantly increased in gVPLA2-KO mice, indicating that lung endothelial expression of gVPLA2 is critical in vivo. In summary, these results demonstrate an important role for gVPLA2 in mediating MRSA-induced lung EC permeability and ALI. Thus, gVPLA2 may represent a novel therapeutic target in ALI/ARDS caused by bacterial infection.

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Dexmedetomidine alleviates pulmonary edema through the epithelial sodium channel (ENaC) via the PI3K/Akt/Nedd4-2 pathway in LPS-induced acute lung injury

Immunologic Research ◽

10.1007/s12026-021-09176-6 ◽

2021 ◽

Author(s):

Yuanxu Jiang ◽

Mingzhu Xia ◽

Jing Xu ◽

Qiang Huang ◽

Zhongliang Dai ◽

...

Keyword(s):

Acute Lung Injury ◽

Lung Injury ◽

Sodium Channel ◽

Pulmonary Edema ◽

Cell Injury ◽

A549 Cells ◽

Alveolar Epithelial ◽

Phosphorylated Akt ◽

Epithelial Sodium Channel Enac

AbstractDexmedetomidine (Dex), a highly selective α2-adrenergic receptor (α2AR) agonist, has an anti-inflammatory property and can alleviate pulmonary edema in lipopolysaccharide (LPS)-induced acute lung injury (ALI), but the mechanism is still unclear. In this study, we attempted to investigate the effect of Dex on alveolar epithelial sodium channel (ENaC) in the modulation of alveolar fluid clearance (AFC) and the underlying mechanism. Lipopolysaccharide (LPS) was used to induce acute lung injury (ALI) in rats and alveolar epithelial cell injury in A549 cells. In vivo, Dex markedly reduced pulmonary edema induced by LPS through promoting AFC, prevented LPS-induced downregulation of α-, β-, and γ-ENaC expression, attenuated inflammatory cell infiltration in lung tissue, reduced the concentrations of TNF-α, IL-1β, and IL-6, and increased concentrations of IL-10 in bronchoalveolar lavage fluid (BALF). In A549 cells stimulated with LPS, Dex attenuated LPS-mediated cell injury and the downregulation of α-, β-, and γ-ENaC expression. However, all of these effects were blocked by the PI3K inhibitor LY294002, suggesting that the protective role of Dex is PI3K-dependent. Additionally, Dex increased the expression of phosphorylated Akt and reduced the expression of Nedd4-2, while LY294002 reversed the effect of Dex in vivo and in vitro. Furthermore, insulin-like growth factor (IGF)-1, a PI3K agonists, promoted the expression of phosphorylated Akt and reduced the expression of Nedd4-2 in LPS-stimulated A549 cells, indicating that Dex worked through PI3K, and Akt and Nedd4-2 are downstream of PI3K. In conclusion, Dex alleviates pulmonary edema by suppressing inflammatory response in LPS-induced ALI, and the mechanism is partly related to the upregulation of ENaC expression via the PI3K/Akt/Nedd4-2 signaling pathway.

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H2S in acute lung injury: a therapeutic dead end(?)

Intensive Care Medicine Experimental ◽

10.1186/s40635-020-00324-0 ◽

2020 ◽

Vol 8 (S1) ◽

Author(s):

Tamara Merz ◽

Nicole Denoix ◽

Martin Wepler ◽

Holger Gäßler ◽

David A. C. Messerer ◽

...

Keyword(s):

Hydrogen Sulfide ◽

Acute Lung Injury ◽

Lung Injury ◽

Circulatory Shock ◽

Therapeutic Window ◽

Pharmacokinetics And Pharmacodynamics ◽

Clinical Reality ◽

Dead End

AbstractThis review addresses the plausibility of hydrogen sulfide (H2S) therapy for acute lung injury (ALI) and circulatory shock, by contrasting the promising preclinical results to the present clinical reality. The review discusses how the narrow therapeutic window and width, and potentially toxic effects, the route, dosing, and timing of administration all have to be balanced out very carefully. The development of standardized methods to determine in vitro and in vivo H2S concentrations, and the pharmacokinetics and pharmacodynamics of H2S-releasing compounds is a necessity to facilitate the safety of H2S-based therapies. We suggest the potential of exploiting already clinically approved compounds, which are known or unknown H2S donors, as a surrogate strategy.

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Protectin conjugates in tissue regeneration 1 restores lipopolysaccharide-induced pulmonary endothelial glycocalyx loss via ALX/SIRT1/NF-kappa B axis

Respiratory Research ◽

10.1186/s12931-021-01793-x ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Xin-Yang Wang ◽

Xin-Yu Li ◽

Cheng-Hua Wu ◽

Yu Hao ◽

Pan-Han Fu ◽

...

Keyword(s):

Acute Lung Injury ◽

Lung Injury ◽

Inflammatory Cytokines ◽

Tissue Regeneration ◽

Umbilical Vein ◽

Endothelial Glycocalyx ◽

Lipid Mediator ◽

Protective Effects ◽

Pulmonary Vascular Permeability

Abstract Background Endothelial glycocalyx loss is integral to increased pulmonary vascular permeability in sepsis-related acute lung injury. Protectin conjugates in tissue regeneration 1 (PCTR1) is a novel macrophage-derived lipid mediator exhibiting potential anti-inflammatory and pro-resolving benefits. Methods PCTR1 was administrated intraperitoneally with 100 ng/mouse after lipopolysaccharide (LPS) challenged. Survival rate and lung function were used to evaluate the protective effects of PCTR1. Lung inflammation response was observed by morphology and inflammatory cytokines level. Endothelial glycocalyx and its related key enzymes were measured by immunofluorescence, ELISA, and Western blot. Afterward, related-pathways inhibitors were used to identify the mechanism of endothelial glycocalyx response to PCTR1 in mice and human umbilical vein endothelial cells (HUVECs) after LPS administration. Results In vivo, we show that PCTR1 protects mice against lipopolysaccharide (LPS)-induced sepsis, as shown by enhanced the survival and pulmonary function, decreased the inflammatory response in lungs and peripheral levels of inflammatory cytokines such as tumor necrosis factor-α, interleukin-6, and interleukin-1β. Moreover, PCTR1 restored lung vascular glycocalyx and reduced serum heparin sulphate (HS), syndecan-1 (SDC-1), and hyaluronic acid (HA) levels. Furthermore, we found that PCTR1 downregulated heparanase (HPA) expression to inhibit glycocalyx degradation and upregulated exostosin-1 (EXT-1) protein expression to promote glycocalyx reconstitution. Besides, we observed that BAY11-7082 blocked glycocalyx loss induced by LPS in vivo and in vitro, and BOC-2 (ALX antagonist) or EX527 (SIRT1 inhibitor) abolished the restoration of HS in response to PCTR1. Conclusion PCTR1 protects endothelial glycocalyx via ALX receptor by regulating SIRT1/NF-κB pathway, suggesting PCTR1 may be a significant therapeutic target for sepsis-related acute lung injury.

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