scholarly journals A paradoxical protective role for the proinflammatory peptide substance P receptor (NK1R) in acute hyperoxic lung injury

2009 ◽  
Vol 297 (4) ◽  
pp. L687-L697 ◽  
Author(s):  
Marwan Dib ◽  
Zsuzsanna Zsengeller ◽  
Alex Mitsialis ◽  
Bao Lu ◽  
Stewart Craig ◽  
...  

The neuropeptide substance P manifests its biological functions through ligation of a G protein-coupled receptor, the NK1R. Mice with targeted deletion of this receptor reveal a preponderance of proinflammatory properties resulting from ligand activation, demonstrating a neurogenic component to multiple forms of inflammation and injury. We hypothesized that NK1R deficiency would afford a similar protection from inflammation associated with hyperoxia. Counter to our expectations, however, NK1R−/− animals suffered significantly worse lung injury compared with wild-type mice following exposure to 90% oxygen. Median survival was shortened to 84 h for NK1R−/− mice from 120 h for wild-type animals. Infiltration of inflammatory cells into the lungs was significantly increased; NK1R−/− animals also exhibited increased pulmonary edema, hemorrhage, and bronchoalveolar lavage fluid protein levels. TdT-mediated dUTP nick end labeling (TUNEL) staining was significantly elevated in NK1R−/− animals following hyperoxia. Furthermore, induction of metallothionein and Na+-K+-ATPase was accelerated in NK1R−/− compared with wild-type mice, consistent with increased oxidative injury and edema. In cultured mouse lung epithelial cells in 95% O2, however, addition of substance P promoted cell death, suggesting the neurogenic component of hyperoxic lung injury is mediated by additional mechanisms in vivo. Release of bioactive constituents including substance P from sensory neurons results from activation of the vanilloid receptor, TRPV1. In mice with targeted deletion of the TRPV1 gene, acute hyperoxic injury is attenuated relative to NK1R−/− animals. Our findings thus reveal a major neurogenic mechanism in acute hyperoxic lung injury and demonstrate concerted actions of sensory neurotransmitters revealing significant protection for NK1R-mediated functions.

2003 ◽  
Vol 285 (1) ◽  
pp. L250-L257 ◽  
Author(s):  
Danielle Morse ◽  
Leo E. Otterbein ◽  
Simon Watkins ◽  
Sean Alber ◽  
Zhihong Zhou ◽  
...  

Hyperoxia generates an oxidative stress in the mouse lung, which activates the major stress-inducible kinase pathways, including c-Jun NH2-terminal kinase (JNK). We examined the effect of Jnk1 gene deletion on in vivo responses to hyperoxia in mice. The survival of Jnk1-/- mice was reduced relative to wild-type mice after exposure to continuous hyperoxia. Jnk1- /- mice displayed higher protein concentration in bronchoalveolar lavage (BAL) fluid and increased expression of heme oxygenase-1, a stress-inducible gene, after 65 h of hyperoxia. Contrary to other markers of injury, the leukocyte count in BAL fluid of Jnk1- /- mice was markedly diminished relative to that of wild-type mice. The decrease in BAL leukocyte count was not associated with any decrease in lung myeloperoxidase activity at baseline or after hyperoxia treatment. Pretreatment with inhaled lipopolysaccharide increased BAL neutrophil content and extended hyperoxia survival time to a similar extent in Jnk1- /- and wild-type mice. Associated with increased mortality, Jnk1- /- mice had increased pulmonary epithelial cell apoptosis after exposure to hyperoxia compared with wild-type mice. These results indicate that JNK pathways participate in adaptive responses to hyperoxia in mice.


1999 ◽  
Vol 277 (6) ◽  
pp. L1214-L1223 ◽  
Author(s):  
Funmei Yang ◽  
Jacqueline J. Coalson ◽  
Heather H. Bobb ◽  
Jacqueline D. Carter ◽  
Jameela Banu ◽  
...  

Oxidative stress plays a central role in the pathogenesis of acute and chronic pulmonary diseases. Safe sequestration of iron, which participates in the formation of the hydroxyl radical, is crucial in the lung's defense. We used a mouse line defective in the major iron transport protein transferrin to investigate the effect of aberrant iron metabolism on the lung's defense against oxidative injury. The tolerance to hyperoxic lung injury was greater in the hypotransferrinemic than in wild-type mice as documented by histopathology and biochemical indexes for lung damage. There was no increase in the levels of intracellular antioxidants, inflammatory cytokines, and heme oxygenase-1 in the hypotransferrinemic mouse lung compared with those in wild-type mice. However, there were elevated expressions of ferritin and lactoferrin in the lung of hypotransferrinemic mice, especially in the alveolar macrophages. Our results suggest that pulmonary lactoferrin and ferritin protect animals against oxidative stress, most likely via their capacity to sequester iron, and that alveolar macrophages are the key participants in iron detoxification in the lower respiratory tract.


2017 ◽  
Vol 42 (5) ◽  
pp. 1907-1919 ◽  
Author(s):  
Qiuyue Zhang ◽  
Di Wu ◽  
Yang Yang ◽  
Tingting Liu ◽  
Hongyu Liu

Background/Aims: Dexmedetomidine (Dex), a specific agonist of α2-adrenoceptor, has been reported to have extensive pharmacological effects. In this study, we focused on the protective effect of Dex on hyperoxia-induced acute lung injury and further explored its possible molecular mechanisms. Methods: The model of hyperoxia-induced acute lung injury was established by continuous inhalation of oxygen (FiO2= 0.90) for 7 d in neonatal rats in vivo. The in vitro experiments were carried out in LPS/ATP or hyperoxia-treated RAW264.7 cells. ELISA, western blot, TUNEL staining, and immunohistochemistry staining assays were performed and the commercial kits were used to assess the beneficial effect of Dex on hyperoxia-induced acute lung injury. Results: According to our results, Dex treatment attenuated hyperoxia-induced acute lung injury via decreasing the lung wet/dry(W/D) weight ratio and mitigating pathomorphologic changes. Moreover, the oxidative stress injury, inflammatory reaction, and apoptosis in lung epithelial cells were inhibited by Dex treatment. In addition, the activation of NLRP3 inflammasome was restrained by Dex both in lung tissue in vivo and RAW264.7 cells in vitro. Conclusion: These data provide evidence that Dex may ameliorate hyperoxia-induced acute lung injury, which suggests a potential clinical application of Dex in long-term supplemental oxygen therapy.


Antioxidants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1874
Author(s):  
Hye-Youn Cho ◽  
Laura Miller-DeGraff ◽  
Ligon A. Perrow ◽  
Wesley Gladwell ◽  
Vijayalakshmi Panduri ◽  
...  

NRF2 protects against oxidant-associated airway disorders via cytoprotective gene induction. To examine if NRF2 is an important determinant of respiratory syncytial virus (RSV) susceptibility after neonate lung injury, Nrf2-deficient (Nrf2−/−) and wild-type (Nrf2+/+) mice neonatally exposed to hyperoxia were infected with RSV. To investigate the prenatal antioxidant effect on neonatal oxidative lung injury, time-pregnant Nrf2−/−and Nrf2+/+mice were given an oral NRF2 agonist (sulforaphane) on embryonic days 11.5–17.5, and offspring were exposed to hyperoxia. Bronchoalveolar lavage and histopathologic analyses determined lung injury. cDNA microarray analyses were performed on placenta and neonatal lungs. RSV-induced pulmonary inflammation, injury, oxidation, and virus load were heightened in hyperoxia-exposed mice, and injury was more severe in hyperoxia-susceptible Nrf2−/− mice than in Nrf2+/+ mice. Maternal sulforaphane significantly alleviated hyperoxic lung injury in both neonate genotypes with more marked attenuation of severe neutrophilia, edema, oxidation, and alveolarization arrest in Nrf2−/− mice. Prenatal sulforaphane altered different genes with similar defensive functions (e.g., inhibition of cell/perinatal death and inflammation, potentiation of angiogenesis/organ development) in both strains, indicating compensatory transcriptome changes in Nrf2−/− mice. Conclusively, oxidative injury in underdeveloped lungs NRF2-dependently predisposed RSV susceptibility. In utero sulforaphane intervention suggested NRF2-dependent and -independent pulmonary protection mechanisms against early-life oxidant injury.


2011 ◽  
Vol 300 (3) ◽  
pp. L422-L429 ◽  
Author(s):  
Tricia I. Lozon ◽  
Alison J. Eastman ◽  
Gustavo Matute-Bello ◽  
Peter Chen ◽  
Teal S. Hallstrand ◽  
...  

Supplemental O2is commonly employed in patients with respiratory failure; however, hyperoxia is also a potential contributor to lung injury. In animal models, hyperoxia causes oxidative stress in the lungs, resulting in increased inflammation, edema, and permeability. We hypothesized that oxidative stress from prolonged hyperoxia leads to endoplasmic reticulum (ER) stress, resulting in activation of the unfolded protein response (UPR) and induction of CCAAT enhancer-binding protein homologous protein (CHOP), a transcription factor associated with cell death in the setting of persistent ER stress. To test this hypothesis, we exposed the mouse lung epithelial cell line MLE-12 to 95% O2for 8–24 h and evaluated for evidence of UPR induction and CHOP induction. Hyperoxia caused increased CHOP expression without other evidence of UPR activation. Because CHOP expression is preceded by phosphorylation of the α-subunit of the eukaryotic initiation factor-2 (eIF2α), we evaluated the role of double-stranded RNA-activated protein kinase (PKR), a non-UPR-associated eIF2α kinase. Hyperoxia caused PKR phosphorylation, and RNA interference knockdown of PKR attenuated hyperoxia-induced CHOP expression. In vivo, hyperoxia induced PKR phosphorylation and CHOP expression in the lungs without other biochemical evidence for ER stress. Additionally, Ddit3−/−(CHOP-null) mice had increased lung edema and permeability, indicating a previously unknown protective role for CHOP after prolonged hyperoxia. We conclude that hyperoxia increases CHOP expression via an ER stress-independent, PKR-dependent pathway and that increased CHOP expression protects against hyperoxia-induced lung injury.


2005 ◽  
Vol 25 (11) ◽  
pp. 1466-1475 ◽  
Author(s):  
Yan Qu ◽  
Jing Chen ◽  
Luna Benvenisti-Zarom ◽  
Xin Ma ◽  
Raymond F Regan

The heme oxygenase (HO) enzymes catalyze the rate-limiting step in the breakdown of heme to iron, carbon monoxide, and biliverdin. A prior cell culture study demonstrated that deletion of HO-2, the isoform constitutively expressed in neurons, attenuated hemoglobin (Hb) neurotoxicity. The present study tested the hypothesis that HO-2 gene deletion is cytoprotective in a model of Hb toxicity in vivo. Stereotactic injection of 6 μL stroma-free Hb (SFHb) into the striatum significantly increased protein oxidation in wild-type mice at 24 to 72 h, as detected by an assay for carbonyl groups. At 72 h, carbonylation was increased 2.5-fold compared with that in the contralateral striatum. In HO-2 knockout mice, protein oxidation was not increased at 24 h, and was increased by only 1.7-fold at 72 h. Similarly, striatal lipid peroxidation, as detected by the malondialdehyde assay, was significantly greater in the SFHb-injected striata of wild-type mice than in knockout mice. Striatal cell viability, determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, was 45.0%±6.3% of that in contralateral striata in wild-type mice at 72 h; it was increased to 85%±8% in knockouts. Heme oxygenase-2 gene deletion did not alter weight loss or mortality after SFHb injection. Baseline striatal HO-1 expression was similar in knockout and wild-type mice; induction after SFHb injection occurred more rapidly in the latter. These results suggest that HO-2 gene deletion protects striatal cells from the oxidative toxicity of Hb in vivo. Pharmacologic or genetic strategies that target HO-2 may be beneficial after central nervous system hemorrhage, and warrant further investigation.


1996 ◽  
Vol 14 (6) ◽  
pp. 556-568 ◽  
Author(s):  
P J Lee ◽  
J Alam ◽  
S L Sylvester ◽  
N Inamdar ◽  
L Otterbein ◽  
...  

2013 ◽  
Vol 2013 ◽  
pp. 1-14 ◽  
Author(s):  
Hui Wang ◽  
Jing Fan ◽  
Nan-lin Li ◽  
Jun-tang Li ◽  
Shi-fang Yuan ◽  
...  

Anesthetic isoflurane (ISO) has immunomodulatory effects. In the present study, we investigated whether a subanesthetic dose of ISO (0.7%) protected against zymosan (ZY) induced inflammatory responses in the murine lung and isolated neutrophils. At 1 and 6 hrs after ZY administration intraperitoneally, ISO was inhaled for 1 hr, and 24 hrs later, lung inflammation and injury were assessed. We found that ISO improved the survival rate of mice and mitigated lung injury as characterized by the histopathology, wet-to-dry weight ratio, protein leakage, and lung function index. ISO significantly attenuated ZY-induced lung neutrophil recruitment and inflammation. This was suggested by the downregulation of (a) endothelial adhesion molecule expression and myeloperoxidase (MPO) activity in lung tissue and polymorphonuclear neutrophils (b) chemokines, and (c) proinflammatory cytokines in BALF. Furthermore, ZY-induced nuclear translocation and DNA-binding activity of NF-κB p65 were also reduced by ISO. ISO treatment inhibited iNOS expression and activity, as well as subsequent nitric oxide generation. Consistent with thesein vivoobservations,in vitrostudies confirmed that ISO blocked NF-κB and iNOS activation in primary mouse neutrophils challenged by ZY. These results provide evidence that 0.7% ISO ameliorates inflammatory responses in ZY-treated mouse lung and primary neutrophils.


2020 ◽  
Author(s):  
Jun Wu ◽  
Dingyun Song ◽  
Zhongwen Li ◽  
Baojie Guo ◽  
Yani Xiao ◽  
...  

AbstractLung injury and fibrosis represent the most significant outcomes of severe and acute lung disorders, including COVID-19. However, there are still no effective drugs to treat lung injury and fibrosis. In this study, we report the generation of clinical-grade human embryonic stem cells (hESCs)-derived immunity- and matrix-regulatory cells (IMRCs) produced under good manufacturing practice (GMP) requirements, that can treat lung injury and fibrosis in vivo. We generate IMRCs by sequentially differentiating hESCs with serum-free reagents. IMRCs possess a unique gene expression profile distinct from umbilical cord mesenchymal stem cells (UCMSCs), such as higher levels of proliferative, immunomodulatory and anti-fibrotic genes. Moreover, intravenous delivery of IMRCs inhibits both pulmonary inflammation and fibrosis in mouse models of lung injury, and significantly improves the survival rate of the recipient mice in a dose-dependent manner, likely through paracrine regulatory mechanisms. IMRCs are superior to both primary UCMSCs and FDA-approved pirfenidone, with an excellent efficacy and safety profile in mice and monkeys. In light of public health crises involving pneumonia, acute lung injury (ALI) and acute respiratory distress syndrome (ARDS), our findings suggest that IMRCs are ready for clinical trials on lung disorders.


2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Jiali Li ◽  
Shichao Li ◽  
Yang Li ◽  
Guanjie Yuan ◽  
Yaqi Shen ◽  
...  

Abstract Background Immunochemotherapy is a potent anti-tumor strategy, however, how to select therapeutic drugs to enhance the combined therapeutic effect still needs to be explored. Methods and results Herein, a magnetic resonance nanoprobe (MnP@Lip) with STING (Stimulator of INterferon Genes) activation character was synthesized and co-administered with platinum-based chemotherapeutics for enhanced immunochemotherapy. MnP@Lip nanoparticles was prepared by simple fabrication process with good reproducibility, pH-sensitive drug release behavior and biocompatibility. In vitro experiments elucidated that Mn2+ can promote the polarization of M0 and/or M2 macrophages to M1 phenotype, and promote the maturation of BMDC cells. Upon Mn2+ treatment, the STING pathway was activated in tumor cells, mouse lung epithelial cells, and immune cells. More importantly, anti-tumor experiments in vivo proved that MnP@Lip combined with platinum-based chemotherapeutics increased T cells infiltration in the tumor microenvironment, and inhibited tumor growth in the orthotopic therapeutic and postoperative tumor models. Conclusions This kind of therapeutic strategy that combined MnP@Lip nanoparticles with platinum-based chemotherapeutics may provide a novel insight for immunochemotherapy. Graphical Abstract


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