Simulated Aeromedical Evacuation Exacerbates Burn Induced Lung Injury: Targeting Mitochondrial DNA for Reversal

Abstract Background: Aeromedical evacuation of patients with burn trauma is an important transport method at both wartime and peacetime, which exposes patients to prolonged periods of hypobaric hypoxia. However, the effects of such exposure on burn injury, particularly on burn induced lung injury are largely unexplored. The objective of this study is to investigate the effect of hypobaric hypoxia on burn induced lung injury and to discuss the possible mechanism by using a rat burn model. Methods: Male wistar rats inflicted with 30% total body surface area burn were exposed to hypobaric hypoxia condition (simulated 2000m altitude) or normoxia control for 24 h. Deoxyribonuclease I was systemically administrated as treatment intervention. Systemic inflammatory mediators and mitochondrial deoxyribonucleic acid level were detected. The histopathological examination, and acute lung injury score were determined. Malonaldehyde content, myeloperoxidase activity, and the nucleotide-binding oligomerization domain-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome level in the lung tissue were measured. Data among groups were compared by using analysis of variance followed by the post hoc analysis of Tukey's test. Results: Burn resulted in remarkably higher level of systemic inflammatory cytokines and mitochondrial deoxyribonucleic acid release, which was further heightened by hypobaric hypoxia exposure. Moreover, hypobaric hypoxia exposure gave rise to increased NLRP3 inflammasome expression, elevated malonaldehyde content and myeloperoxidase activity in the lung. Burn induced lung injury was exacerbated as shown by histopathological examination and acute lung injury score. Administration of deoxyribonuclease I markedly reduced mitochondrial deoxyribonucleic acid release and systemic inflammatory cytokines production. Furthermore, NLRP3 inflammasome level in the lung tissue was decreased and burn induced lung injury was ameliorated. Conclusions: Our results suggested that simulated aeromedical evacuation further increased the burn induced mitochondrial deoxyribonucleic acid release and exacerbated burn induced inflammation and lung injury. Deoxyribonuclease I reduced the release of mitochondrial deoxyribonucleic acid and limited the mitochondrial deoxyribonucleic acid-induced systemic inflammation, ameliorated burn-induced acute lung injury. Intervening mitochondrial deoxyribonucleic acid level could be a potential target to protect from burn-induced lung injury during aeromedical conditions and provide with safer air evacuations for severely burned patients.

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Simulated aeromedical evacuation exacerbates burn induced lung injury: targeting mitochondrial DNA for reversal

Military Medical Research ◽

10.1186/s40779-021-00320-9 ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

Meng-Jing Xiao ◽

Xiao-Fang Zou ◽

Bin Li ◽

Bao-Long Li ◽

Shi-Jian Wu ◽

...

Keyword(s):

Lung Injury ◽

Nlrp3 Inflammasome ◽

Hypobaric Hypoxia ◽

Dnase I ◽

Treatment Intervention ◽

Aeromedical Evacuation ◽

Hypoxia Exposure ◽

Histopathological Evaluation ◽

Lung Injuries ◽

Mda Content

Abstract Background Aeromedical evacuation of patients with burn trauma is an important transport method in times of peace and war, during which patients are exposed to prolonged periods of hypobaric hypoxia; however, the effects of such exposure on burn injuries, particularly on burn-induced lung injuries, are largely unexplored. This study aimed to determine the effects of hypobaric hypoxia on burn-induced lung injuries and to investigate the underlying mechanism using a rat burn model. Methods A total of 40 male Wistar rats were randomly divided into four groups (10 in each group): sham burn (SB) group, burn in normoxia condition (BN) group, burn in hypoxia condition (BH) group, and burn in hypoxia condition with treatment intervention (BHD) group. Rats with 30% total body surface area burns were exposed to hypobaric hypoxia (2000 m altitude simulation) or normoxia conditions for 4 h. Deoxyribonuclease I (DNase I) was administered systemically as a treatment intervention. Systemic inflammatory mediator and mitochondrial deoxyribonucleic acid (mtDNA) levels were determined. A histopathological evaluation was performed and the acute lung injury (ALI) score was determined. Malonaldehyde (MDA) content, myeloperoxidase (MPO) activity, and the nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome level were determined in lung tissues. Data among groups were compared using analysis of variance followed by Tukey’s test post hoc analysis. Results Burns resulted in a remarkably higher level of systemic inflammatory cytokines and mtDNA release, which was further heightened by hypobaric hypoxia exposure (P < 0.01). Moreover, hypobaric hypoxia exposure gave rise to increased NLRP3 inflammasome expression, MDA content, and MPO activity in the lung (P < 0.05 or P < 0.01). Burn-induced lung injuries were exacerbated, as shown by the histopathological evaluation and ALI score (P < 0.01). Administration of DNase I markedly reduced mtDNA release and systemic inflammatory cytokine production. Furthermore, the NLRP3 inflammasome level in lung tissues was decreased and burn-induced lung injury was ameliorated (P < 0.01). Conclusions Our results suggested that simulated aeromedical evacuation further increased burn-induced mtDNA release and exacerbated burn-induced inflammation and lung injury. DNase I reduced the release of mtDNA, limited mtDNA-induced systemic inflammation, and ameliorated burn-induced ALI. The intervening mtDNA level is thus a potential target to protect from burn-induced lung injury during aeromedical conditions and provides safer air evacuations for severely burned patients.

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Inhibition of Sphingosine Kinase 1 Attenuates Sepsis-induced Microvascular Leakage via Inhibiting Macrophage NLRP3 Inflammasome Activation in Mice

Anesthesiology ◽

10.1097/aln.0000000000003192 ◽

2020 ◽

Vol 132 (6) ◽

pp. 1503-1515 ◽

Cited By ~ 1

Author(s):

Ming Zhong ◽

Wei Wu ◽

Yingqin Wang ◽

Hailei Mao ◽

Jieqiong Song ◽

...

Keyword(s):

Lung Injury ◽

Healthy Volunteers ◽

Mrna Expression ◽

Nlrp3 Inflammasome ◽

Cecal Ligation ◽

Lung Injury Score ◽

Blue Dye ◽

Inflammasome Activation ◽

Myeloperoxidase Activity ◽

Nlrp3 Inflammasome Activation

Abstract Background Sepsis is the overwhelming inflammatory response to infection, in which nucleotide-binding oligomerization domain-like receptor containing pyrin domain 3 (NLRP3) inflammasome plays a crucial role. Shingosine-1-phosphate is reported to evoke NLRP3 inflammasome activation. Sphingosine kinase 1 (SphK1) is the major kinase that catalyzes bioactive lipid shingosine-1–phosphate formation and its role in sepsis remains uncertain. The authors hypothesize that SphK1 elicits NLRP3 inflammasome activation and exacerbates sepsis. Methods Peripheral blood mononuclear cells were isolated from septic patients and healthy volunteers to measure messenger RNA (mRNA) expression. In mice, sepsis was induced by cecal ligation and puncture. Bone marrow–derived macrophages were prepared from C57BL/6J wild-type, Casp1−/−, Nlrp3−/− and SphK1−/− mice. PF-543 was used as the specific inhibitor of SphK1. Mortality, peripheral perfusion, lung Evan’s blue dye index, lung wet/dry ratio, lung injury score, lung myeloperoxidase activity, NLRP3 activation, and function of endothelial adherens junction were measured. Results SphK1 mRNA expression was higher in cells from septic patients versus healthy volunteers (septic patients vs. healthy volunteers: 50.9 ± 57.0 fold change vs. 1.2 ± 0.1 fold change, P < 0.0001) and was positively correlated with IL-1β mRNA expression in these cells (r = 0.537, P = 0.012) and negatively correlated with PaO2/Fio2 ratios (r = 0.516, P = 0.017). In mice that had undergone cecal ligation and puncture, the 5-day mortality was 30% in PF-543–treated group and 80% in control group (n = 10 per group, P = 0.028). Compared with controls, PF-543–treated mice demonstrated improved peripheral perfusion and alleviated extravascular Evan’s blue dye effusion (control vs. PF-543: 25.5 ± 3.2 ng/g vs. 18.2 ± 1.4 ng/g, P < 0.001), lower lung wet/dry ratio (control vs. PF-543: 8.0 ± 0.2 vs. 7.1 ± 0.4, P < 0.0001), descending lung injury score, and weaker lung myeloperoxidase activity. Inhibition of SphK1 suppressed caspase-1 maturation and interleukin-1β release through repressing NLRP3 inflammasome activation, and subsequently stabilized vascular endothelial cadherin through suppressing interleukin-1β–evoked Src-mediated phosphorylation of vascular endothelial cadherin. Conclusions SphK1 plays a crucial role in NLRP3 inflammasome activation and contributes to lung injury and mortality in mice polymicrobial sepsis. Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New

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Inhibition of microsomal prostaglandin E synthase-1 ameliorates acute lung injury in mice

Journal of Translational Medicine ◽

10.1186/s12967-021-03016-9 ◽

2021 ◽

Vol 19 (1) ◽

Author(s):

Malarvizhi Gurusamy ◽

Saeed Nasseri ◽

Dileep Reddy Rampa ◽

Huiying Feng ◽

Dongwon Lee ◽

...

Keyword(s):

Acute Lung Injury ◽

Lung Injury ◽

Cecal Ligation ◽

Experimental Models ◽

Lung Injury Score ◽

Prostaglandin E ◽

Myeloperoxidase Activity ◽

Prostaglandin E Synthase ◽

To Receive ◽

Microsomal Prostaglandin E Synthase

Abstract Background To examine the effects of BI 1029539 (GS-248), a novel selective human microsomal prostaglandin E synthase-1 (mPGES-1) inhibitor, in experimental models of acute lung injury (ALI) and sepsis in transgenic mice constitutively expressing the mPGES1 (Ptges) humanized allele. Methods Series 1: Lipopolysaccharide (LPS)-induced ALI. Mice were randomized to receive vehicle, BI 1029539, or celecoxib. Series 2: Cecal ligation and puncture-induced sepsis. Mice were randomized to receive vehicle or BI 1029539. Results Series 1: BI 1029539 or celecoxib reduced LPS-induced lung injury, with reduction in neutrophil influx, protein content, TNF-ɑ, IL-1β and PGE2 levels in bronchoalveolar lavage (BAL), myeloperoxidase activity, expression of mPGES-1, cyclooxygenase (COX)-2 and intracellular adhesion molecule in lung tissue compared with vehicle-treated mice. Notably, prostacyclin (PGI2) BAL concentration was only lowered in celecoxib-treated mice. Series 2: BI 1029539 significantly reduced sepsis-induced BAL inflammatory cell recruitment, lung injury score and lung expression of mPGES-1 and inducible nitric oxide synthase. Treatment with BI 1029539 also significantly prolonged survival of mice with severe sepsis. Anti-inflammatory and anti-migratory effect of BI 1029539 was confirmed in peripheral blood leukocytes from healthy volunteers. Conclusions BI 1029539 ameliorates leukocyte infiltration and lung injury resulting from both endotoxin-induced and sepsis-induced lung injury.

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Juglone Attenuates Sepsis-Induced Acute Lung Injury via Suppression of the TLR4/Nf-κb Pathway

Current Topics in Nutraceutical Research ◽

10.37290/ctnr2641-452x.18:201-206 ◽

2020 ◽

Vol 18 (2) ◽

pp. 201-206

Author(s):

Qiu Nan ◽

Xu Xinmei ◽

He Yingying ◽

Fan Chengfen

Keyword(s):

Acute Lung Injury ◽

Lung Injury ◽

Nuclear Factor Kappa B ◽

Cecal Ligation ◽

Myeloperoxidase Activity ◽

Nuclear Factor ◽

Cecal Ligation And Puncture ◽

Toll Like Receptor ◽

Toll Like Receptor 4 ◽

Nuclear Factor Kappa

Sepsis, with high mortality, induces deleterious organ dysfunction and acute lung injury. Natural compounds show protective effect against sepsis-induced acute lung injury. Juglone, a natural naphthoquinone, demonstrates pharmacological actions as a pro-apoptotic substrate in tumor treatment and anti-inflammation substrate in organ injury. In this study, the influence of juglone on sepsis-induced acute lung injury was investigated. First, a septic mice model was established via cecal ligation and puncture, and then verified via histopathological analysis of lung tissues, the wet/dry mass ratio and myeloperoxidase activity was determined. Cecal ligation and puncture could induce acute lung injury in septic mice, as demonstrated by alveolar damage and increase of wet/dry mass ratio and myeloperoxidase activity. However, intragastric administration juglone attenuated cecal ligation and puncture-induced acute lung injury. Secondly, cecal ligation and puncture-induced increase of inflammatory cells in bronchoalveolar lavage fluid was also alleviated by the administration of juglone. Similarly, the protective effect of juglone against cecal ligation and puncture-induced acute lung injury was accompanied by a reduction of pro-inflammatory factor secretion in bronchoalveolar lavage fluid and lung tissues. Cecal ligation and puncture could activate toll-like receptor 4/nuclear factor-kappa B signaling pathway, and administration of juglone suppressed toll-like receptor 4/nuclear factor-kappa B activation. In conclusion, juglone attenuated cecal ligation and puncture-induced lung damage and inflammatory response through inactivation of toll-like receptor 4/nuclear factor-kappa B, suggesting a potential therapeutic strategy in the treatment of sepsis-induced acute lung injury.

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Glycyrrhetinic acid alleviates acute lung injury by PI3K/AKT suppressing macrophagic Nlrp3 inflammasome activation

Biochemical and Biophysical Research Communications ◽

10.1016/j.bbrc.2020.08.044 ◽

2020 ◽

Vol 532 (4) ◽

pp. 555-562

Author(s):

Kai Wang ◽

Yi Zhang ◽

Yue Cao ◽

Zhimian Shi ◽

Yike Lin ◽

...

Keyword(s):

Acute Lung Injury ◽

Lung Injury ◽

Nlrp3 Inflammasome ◽

Glycyrrhetinic Acid ◽

Inflammasome Activation ◽

Nlrp3 Inflammasome Activation

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Vanillin protects lipopolysaccharide-induced acute lung injury by inhibiting ERK1/2, p38 and NF-κB pathway

Future Medicinal Chemistry ◽

10.4155/fmc-2018-0432 ◽

2019 ◽

Vol 11 (16) ◽

pp. 2081-2094 ◽

Cited By ~ 1

Author(s):

Tingting Guo ◽

Zhenzhong Su ◽

Qi Wang ◽

Wei Hou ◽

Junyao Li ◽

...

Keyword(s):

Acute Lung Injury ◽

Lung Injury ◽

Western Blot ◽

Lung Inflammation ◽

Macrophage Activation ◽

Myeloperoxidase Activity ◽

Histopathological Changes ◽

Tnf Α ◽

Anti Inflammatory ◽

Inflammatory Effect

Aim: Thus far, the anti-inflammatory effect of vanillin in acute lung injury (ALI) has not been studied. This study aimed to investigate the effect of vanillin in lipopolysaccharide (LPS)-induced ALI. Results & methodology: Our study detected the anti-inflammatory effects of vanillin by ELISA and western blot, respectively. Pretreatment of mice with vanillin significantly attenuated LPS-stimulated lung histopathological changes, myeloperoxidase activity and expression levels of proinflammatory cytokines by inhibiting the phosphorylation activities of ERK1/2, p38, AKT and NF-κB p65. In addition, vanillin inhibited LPS-induced TNF-α and IL-6 expression in RAW264.7 cells via ERK1/2, p38 and NF-κB signaling. Conclusion: Vanillin can inhibit macrophage activation and lung inflammation, which suggests new insights for clinical treatment of ALI.

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Huangkui Capsule Attenuates Lipopolysaccharide-Induced Acute Lung Injury and Macrophage Activation by Suppressing Inflammation and Oxidative Stress in Mice

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2021/6626483 ◽

2021 ◽

Vol 2021 ◽

pp. 1-11

Author(s):

Jinfang Deng ◽

Zhenpeng He ◽

Xiuru Li ◽

Wei Chen ◽

Ziwen Yu ◽

...

Keyword(s):

Oxidative Stress ◽

Acute Lung Injury ◽

Lung Injury ◽

Macrophage Activation ◽

Neutrophil Infiltration ◽

Raw 264.7 Cells ◽

Raw 264.7 ◽

Myeloperoxidase Activity ◽

Tnf Α ◽

And Oxidative Stress

Background. Huangkui capsule (HKC) comprises the total flavonoid extract of flowers of Abelmoschus manihot (L.) Medicus. This study aimed to explore the effects of HKC on lipopolysaccharide- (LPS-) induced acute lung injury (ALI) in mice and LPS-stimulated RAW 264.7 cells. Methods. Enzyme-linked immunosorbent assay, histopathology, spectrophotometry, and quantitative real-time polymerase chain reaction were used for the assessments. Statistical analysis was performed using a one-way analysis of variance. Results. LPS significantly increased lung inflammation, neutrophil infiltration, and oxidative stress and downregulated lung miR-451 expression. Treatment with HKC dramatically attenuated the lung wet/dry weight ratio, reduced the total cell count in the bronchoalveolar lavage fluid (BALF), and inhibited myeloperoxidase activity in the lung tissues 24 h after LPS challenge. Histopathological analysis demonstrated that HKC attenuated LPS-induced tissue oedema and neutrophil infiltration in the lung tissues. Additionally, the concentrations of tumour necrosis factor- (TNF-) α and interleukin- (IL-) 6 in BALF and IL-6 in the plasma reduced after HKC administration. Moreover, HKC could enhance glutathione peroxidase and catalase activities and upregulate the expression of miR-451 in the lung tissues. In vitro experiments revealed that HKC inhibited the production of nitric oxide, TNF-α, and IL-6 in LPS-induced RAW 264.7 cells and mouse primary peritoneal macrophages. Additionally, HKC downregulated LPS-induced transcription of TNF-α and IL-6 in RAW 264.7 cells. Conclusions. These findings suggest that HKC has anti-inflammatory and antioxidative effects that may protect mice against LPS-induced ALI and macrophage activation.

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The assessment of severity of lung injury in sepsis

Srpski arhiv za celokupno lekarstvo ◽

10.2298/sarh0412404a ◽

2004 ◽

Vol 132 (11-12) ◽

pp. 404-408

Author(s):

Ljubica Arsenijevic ◽

Nada Popovic ◽

Zvezdana Kojic

Keyword(s):

Acute Lung Injury ◽

Lung Injury ◽

Respiratory Distress Syndrome ◽

Respiratory Distress ◽

Distress Syndrome ◽

Lung Injury Score ◽

Pulmonary Dysfunction ◽

Lethal Outcome ◽

Injury Score ◽

Respiratory Dysfunction

Adult respiratory distress syndrome (ARDS) is an acute and severe pulmonary dysfunction. It is clinically characterized by dyspnea and tachypnea, progressive hypoxemia (within 12-48 hours), reduction of pulmonary compliance and diffuse bilateral infiltrates seen on pulmonary radiogram. Etiological factors giving rise to development of the syndrome are numerous. The acute lung injury (AU) is defined as the inflammation syndrome and increased permeability, which is associated with radiological and physiological disorders. Lung injury score (LIS), which is composed of four components, is used for making a distinction between two separate but rather similar syndromes. The study was aimed at the assessment of the severity of the lung injury in patients who had suffered from sepsis of the gynecological origin and its influence on the outcome of the disease. The total of 43 female patients was analyzed. Twenty patients (46.51%) were diagnosed as having ARDS based on the lung injury score, while 23 patients (53.48%) were diagnosed with acute lung injury. In our series, lung injury score ranged from 0.7 to 3.3 in ARDS patients, and lethal outcome ensued in 11 (55%) cases in this group. As for the patients with the acute lung injury, the score values ranged from 0.3 to 1.3 and only one patient from this group died (4.34%). The obtained results indicate that high values of the lung injury score are suggestive of the severe respiratory dysfunction as well as that lethal outcome is dependent on LIS value.

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