scholarly journals Lower Oligomeric Form of Surfactant Protein D in Murine Acute Lung Injury Induces M1 Subtype Macrophages Through Calreticulin/p38 MAPK Signaling Pathway

2021 ◽  
Vol 12 ◽  
Author(s):  
Dandan Li ◽  
Linyue Pan ◽  
Xiaoju Zhang ◽  
Zhilong Jiang
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Signaling Pathway ◽  
Surfactant Protein ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Tnf Alpha ◽  
Surfactant Protein D ◽  
Downstream Signaling ◽  
Oligomeric Form

Surfactant protein D (SP-D) plays an important role in innate and adaptive immune responses. In this study, we found that the expression of total and de-oligomerized SP-D was significantly elevated in mice with lipopolysaccharide (LPS)-induced acute lung injury (ALI). To investigate the role of the lower oligomeric form of SP-D in the pathogenesis of ALI, we treated bone marrow-derived macrophages (BMDMs) with ALI-derived bronchoalveolar lavage (BAL) and found that SP-D in ALI BAL predominantly bound to calreticulin (CALR) on macrophages, subsequently increasing the phosphorylation of p38 mitogen-activated protein kinase (MAPK) and expression of interleukin (IL)-6, tumor necrosis factor (TNF)-alpha, IL-10, and CD80. However, anti-SP-D (aSP-D) and anti-calreticulin (aCALR) pretreatment reversed the SP-D binding and activation of macrophages induced by ALI BAL or de-oligomerized recombinant murine SP-D (rSP-D). Lack of signal transducer and activator of transcription (STAT)6 in STAT6-/- macrophages resulted in resistance to suppression by aCALR. Further studies in an ALI mouse model showed that blockade of pulmonary SP-D by intratracheal (i.t.), but not intraperitoneal (i.p.), administration of aSP-D attenuated the severity of ALI, accompanied by lower neutrophil infiltrates and expression of IL-1beta and IL-6. Furthermore, i.t. administration of de-oligomerized rSP-D exacerbated the severity of ALI in association with more pro-inflammatory CD45+Siglec-F(-) M1 subtype macrophages and production of IL-6, TNF-alpha, IL-1beta, and IL-18. The results indicated that SP-D in the lungs of murine ALI was de-oligomerized and participated in the pathogenesis of ALI by predominantly binding to CALR on macrophages and subsequently activating the pro-inflammatory downstream signaling pathway. Targeting de-oligomerized SP-D is a promising therapeutic strategy for the treatment of ALI and acute respiratory distress syndrome (ARDS).

scholarly journals EGCG promotes PRKCA expression to alleviate LPS-induced acute lung injury and inflammatory response

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mian Wang ◽  
Hua Zhong ◽  
Xian Zhang ◽  
Xin Huang ◽  
Jing Wang ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Signaling Pathway ◽  
Weight Ratio ◽  
Mapk Signaling ◽  
Mapk Signaling Pathway ◽  
Protective Mechanism ◽  
High Morbidity ◽  
Inflammatory Factor ◽  
Egcg Treatment

AbstractAcute lung injury (ALI), which could be induced by multiple factors such as lipopolysaccharide (LPS), refer to clinical symptoms of acute respiratory failure, commonly with high morbidity and mortality. Reportedly, active ingredients from green tea have anti-inflammatory and anticancer properties, including epigallocatechin-3-gallate (EGCG). In the present study, protein kinase C alpha (PRKCA) is involved in EGCG protection against LPS-induced inflammation and ALI. EGCG treatment attenuated LPS-stimulated ALI in mice as manifested as improved lung injury scores, decreased total cell amounts, neutrophil amounts and macrophage amounts, inhibited the activity of MPO, decreased wet-to-dry weight ratio of lung tissues, and inhibited release of inflammatory cytokines TNF-α, IL-1β, and IL-6. PRKCA mRNA and protein expression showed to be dramatically decreased by LPS treatment while reversed by EGCG treatment. Within LPS-stimulated ALI mice, PRKCA silencing further aggravated, while PRKCA overexpression attenuated LPS-stimulated inflammation and ALI through MAPK signaling pathway. PRKCA silencing attenuated EGCG protection. Within LPS-induced RAW 264.7 macrophages, EGCG could induce PRKCA expression. Single EGCG treatment or Lv-PRKCA infection attenuated LPS-induced increases in inflammatory factors; PRKCA silencing could reverse the suppressive effects of EGCG upon LPS-stimulated inflammatory factor release. In conclusion, EGCG pretreatment inhibits LPS-induced ALI in mice. The protective mechanism might be associated with the inhibitory effects of PRKCA on proinflammatory cytokine release via macrophages and MAPK signaling pathway.

Expression of p38 MAPK in Acute Lung Injury Induced by LPS in Mice

2014 ◽  
Vol 522-524 ◽  
pp. 332-336 ◽  
Author(s):  
Kai Xiu Qin ◽  
Yong Wang ◽  
Hua Gang Jian
Keyword(s):  
Endothelial Cells ◽  
Acute Lung Injury ◽  
Lung Injury ◽  
P38 Mapk ◽  
Inflammatory Cells ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Control Group ◽  
Mitogen Activated Protein ◽  
Set Up

Objective To investigate the expression and roles of p38 mitogen-activated protein kinase (p38 MAPK) in LPS-induced acute lung injury (ALI) in mice. Methods The ALI mice models were set up by intraperineal injection of lipopolysaccharide (LPS). The expressions of p38 MAPK in lung tissues were detected by immunohistochemistry and Western-blot. Results The positive expressions of p38 MAPK distribute mainly in infiltrative inflammatory cells, epithelial cells and endothelial cells. And the level of expression of phosphated p38 MAPK in ALI group were higher obviously than that in the control group, and it reached a peak after two hours. Conclusion p38 MAPK signaling pathway was triggered by ALI induced by endotoxin.

Differential modulation of surfactant protein D under acute and persistent hypoxia in acute lung injury

2012 ◽  
Vol 303 (1) ◽  
pp. L43-L53 ◽  
Author(s):  
Koji Sakamoto ◽  
Naozumi Hashimoto ◽  
Yasuhiro Kondoh ◽  
Kazuyoshi Imaizumi ◽  
Daisuke Aoyama ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Molecular Mechanisms ◽  
De Novo ◽  
Acute Hypoxia ◽  
Surfactant Protein ◽  
Surfactant Protein D ◽  
Alveolar Cells ◽  
Mesenchymal Transition ◽  
Twist Expression

Hypoxia contributes to the development of fibrosis with epithelial-mesenchymal transition (EMT) via stimulation of hypoxia-inducible factor 1α (HIF-1α) and de novo twist expression. Although hypoxemia is associated with increasing levels of surfactant protein D (SP-D) in acute lung injury (ALI), the longitudinal effects of hypoxia on SP-D expression in lung tissue injury/fibrosis have not been fully evaluated. Here, the involvement of hypoxia and SP-D modulation was evaluated in a model of bleomycin-induced lung injury. We also investigated the molecular mechanisms by which hypoxia might modulate SP-D expression in alveolar cells, by using a doxycycline (Dox)-dependent HIF-1α expression system. Tissue hypoxia and altered SP-D levels were present in bleomycin-induced fibrotic lesions. Acute hypoxia induced SP-D expression, supported by the finding that Dox-induced expression of HIF-1α increased SP-D expression. In contrast, persistent hypoxia repressed SP-D expression coupled with an EMT phenotype and twist expression. Long-term expression of HIF-1α caused SP-D repression with twist expression. Ectopic twist expression repressed SP-D expression. The longitudinal observation of hypoxia and SP-D levels in ALI in vivo was supported by the finding that HIF-1α expression stabilized by acute hypoxia induced increasing SP-D expression in alveolar cells, whereas persistent hypoxia induced de novo twist expression in these cells, causing repression of SP-D and acquisition of an EMT phenotype. Thus this is the first study to demonstrate the molecular mechanisms, in which SP-D expression under acute and persistent hypoxia in acute lung injury might be differentially modulated by stabilized HIF-1α expression and de novo twist expression.

scholarly journals The Disruption of the Endothelial Barrier Contributes to Acute Lung Injury Induced by Coxsackievirus A2 Infection in Mice

2021 ◽  
Vol 22 (18) ◽  
pp. 9895
Author(s):  
Wangquan Ji ◽  
Qiang Hu ◽  
Mengdi Zhang ◽  
Chuwen Zhang ◽  
Chen Chen ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Acute Lung Injury ◽  
Lung Injury ◽  
Pulmonary Edema ◽  
Foot And Mouth Disease ◽  
Epidemiological Studies ◽  
Mapk Signaling ◽  
Lung Damage ◽  
Mitogen Activated Protein Kinase ◽  
Endothelial Barrier

Sporadic occurrences and outbreaks of hand, foot, and mouth disease (HFMD) caused by Coxsackievirus A2 (CVA2) have frequently reported worldwide recently, which pose a great challenge to public health. Epidemiological studies have suggested that the main cause of death in critical patients is pulmonary edema. However, the pathogenesis of this underlying comorbidity remains unclear. In this study, we utilized the 5-day-old BALB/c mouse model of lethal CVA2 infection to evaluate lung damage. We found that the permeability of lung microvascular was significantly increased after CVA2 infection. We also observed the direct infection and apoptosis of lung endothelial cells as well as the destruction of tight junctions between endothelial cells. CVA2 infection led to the degradation of tight junction proteins (e.g., ZO-1, claudin-5, and occludin). The gene transcription levels of von Willebrand factor (vWF), endothelin (ET), thrombomodulin (THBD), granular membrane protein 140 (GMP140), and intercellular cell adhesion molecule-1 (ICAM-1) related to endothelial dysfunction were all significantly increased. Additionally, CVA2 infection induced the increased expression of inflammatory cytokines (IL-6, IL-1β, and MCP-1) and the activation of p38 mitogen-activated protein kinase (MAPK). In conclusion, the disruption of the endothelial barrier contributes to acute lung injury induced by CVA2 infection; targeting p38-MAPK signaling may provide a therapeutic approach for pulmonary edema in critical infections of HFMD.

scholarly journals Surfactant Protein D Protects Against Hyperoxia‐Induced Acute Lung Injury In A Murine Model

2006 ◽  
Vol 20 (5) ◽  
Author(s):  
Deepika Jain ◽  
Elena N. Atochina‐Vasserman ◽  
Helchem Kadire ◽  
Yaniv Tomer ◽  
Adam Inch ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Murine Model ◽  
Surfactant Protein ◽  
Surfactant Protein D

scholarly journals Nicorandil Attenuates LPS-Induced Acute Lung Injury by Pulmonary Endothelial Cell Protection via NF-κB and MAPK Pathways

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Mengyu He ◽  
Wen Shi ◽  
Min Yu ◽  
Xiang Li ◽  
Jian Xu ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Endothelial Cell ◽  
Lung Injury ◽  
Adherens Junction ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Protein Accumulation ◽  
Myeloperoxidase Activity ◽  
Cell Protection

Acute lung injury (ALI) is a devastating critical disease characterized by diffuse inflammation and endothelial dysfunction. Increasing evidence, including from our laboratory, has revealed that the opening of ATP-sensitive potassium (KATP) channels has promising anti-inflammation and endothelial protection activities in various disorders. However, the impacts of KATP channels on ALI remain obscure. In this study, we used nicorandil (Nico), a classic KATP channel opener, to investigate whether opening of KATP channels could alleviate ALI with an emphasis on human pulmonary artery endothelial cell (HPAEC) modulation. The results showed that Nico inhibited lipopolysaccharide- (LPS-) induced inflammatory response, protein accumulation, myeloperoxidase activity, and endothelial injury. In vitro, Nico reduced LPS-induced HPAEC apoptosis and the expression of cleaved-caspase-3, caspase-9, and CCAAT/enhancer-binding protein homologous protein (CHOP). Additionally, Nico inhibited inflammation by suppressing monocyte-endothelial adhesion and decreasing the expression of proinflammatory proteins. Moreover, Nico restored the expression and the distribution of adherens junction vascular endothelial- (VE-) cadherin. Further, Nico abolished the increase in intracellular reactive oxygen species (ROS) and the activation of NF-κB and mitogen-activated protein kinase (MAPK) in HPAECs. Glibenclamide (Gli), a nonselective KATP channel blocker, abrogated the effects of Nico, implying that opening of KATP channels contributes to the relief of ALI. Together, our findings indicated that Nico alleviated LPS-induced ALI by protecting ECs function via preventing apoptosis, suppressing endothelial inflammation and reducing oxidative stress, which may be attributed to the inhibition of NF-κB and MAPK signaling pathways.

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