Effects of R-salbutamol on the inflammatory response and acute lung injury in endotoxemic mice.

Salbutamol, which consists of an R-isomer and S-isomer, is an effective and widely used ß2 adrenoreceptor agonist that may possess anti-inflammatory properties in addition to its bronchodilator activity. Whether the salbutamol R-isomer has advantages over its racemic mixture and effectiveness in treating endotoxemia and endotoxin-induced lung injury has not been well studied. In this study, we investigated the preventive and therapeutic effects of R-salbutamol (R-sal), S-salbutamol (S-sal), and their racemic mixture (Rac-sal) on a mouse model of lipopolysaccharide (LPS)-induced endotoxemia. Dexamethasone (Dex) was used for comparison. The results showed that R-sal markedly improved the 7-day survival rate of endotoxic mice when administered before and after LPS treatment. Dex was toxic and accelerated the death of endotoxic mice when administered before LPS injection. Histological examination of the lungs revealed that the LPS challenge resulted in acute lung damage, including inflammatory cell infiltration, thickened alveolar septa, and congestion. R-sal pre-treatment effectively inhibited these changes, accompanied by markedly reduced lung myeloperoxidase levels, serum cytokine levels, and lactate release, significant restoration of lymphocyte count, and reduction of monocyte count. This may have occurred through inhibition of M1 macrophage inflammatory responses by enhancement of ß-arrestin2 expression and suppression of NF-κB activation. Rac-sal exhibited diminished effects compared to that of R-sal, while S-sal showed enhanced release of some inflammatory cytokines. In addition, R-sal pre-treatment showed a better improvement in prognostic pulmonary function on day 4 compared to that by Rac-sal. Collectively, our results indicate the potential benefits of R-sal in regulating inflammatory responses to endotoxemia and endotoxin-induced lung injury.

Endogenous Sulfur Dioxide Improves the Survival Rate of Sepsis by Improving the Oxidative Stress Response during Lung Injury.

Objective: To explore the regulation of endogenous sulfur dioxide on oxidative stress in lung injury induced by sepsis. Method: Forty male Sprague Dawley rats were divided into control, sepsis, sepsis + SO2, and SO2 group randomly used to observe survival rate. The other group of twenty-eight rats were randomly divided as the same manner for mechanism research. The number of WBCS and the percentage of PMN cells were calculated. The microphotographs of morphological changes and the index of quantitative assessment (IQA) of lung tissues were calculated. The ratio of wet/dry (W/D) of lung tissues was calculated. Levels of H2O2, MDA, NO, MPO, SOD, GSH-px, and TNF-α in plasma and lung tissues were measured. Result: The number of WBCS and the percentage of PMN cells decreased in sepsis (p all < 0.05), and rebound in sepsis+SO2 (p all < 0.05). The IQA and W/D of lung tissues increased in sepsis (p for W/D < 0.05), and decreased in sepsis+SO2 (p all < 0.05). H2O2 and MDA of plasma and lung tissues increased in sepsis (p all < 0.05) and rebound in sepsis+SO2 (p for H2O2 of plasma and lung tissues <0.05). NO and MPO of plasma and lung tissues increased in sepsis (p for NO and MPO of lung tissues <0.05) and rebound in sepsis+SO2 (p all < 0.05). SOD of plasma and lung tissues in sepsis group decreased (p all <0.05) and increased in sepsis+SO2 (p all < 0.05). GSH-px of plasma and lung tissues decreased in sepsis (p for plasma <0.05) and increased in sepsis+SO2 (p for GSH-px of lung tissues <0.05). TNF-α of plasma and lung tissues increased in sepsis (p all<0.05) and decreased in sepsis+SO2 (p for lung tissue <0.05). Conclusion: Endogenous sulfur dioxide improves the survival rate of sepsis by improving the oxidative stress response during lung injury.

The Value of Pulmonary Bedside Ultrasound System in the Evaluation of Severity and Prognosis of Acute Lung Injury.

OBJECTIVE: To evaluate the value of pulmonary bedside ultrasound system in the assessment of severity and prognosis of acute lung injury (ALI). METHOD: Seventy-two ALI patients in the intensive care unit (ICU) of our hospital from April 2019 to April 2021 were selected as subjects. The changes of lung ultrasound score (LUS) and parameters at D1, D2, and D3 after admission were analyzed (LUS, oxygenation index (PaO2/FiO2), Acute Physiology and Chronic Health Evaluation II (APACHE-II), and Sequential Organ Failure Assessment (SOFA) score). Pearson correlation analysis was used to assess the relationship between LUS and PaO2/FiO2, APACHE-II score, and SOFA score at D1, D2, and D3. Logistic regression analysis was used for influencing factors for the prognosis of ALI patients. Receiver operating characteristic (ROC) curve was used to analyze the predictive value of baseline LUS, PaO2/FiO2, APACHE-II score, and SOFA score for the prognosis of ALI patients. RESULT: LUSs at D1, D2 and D3 showed an increasing trend with the increase of disease severity (P < 0.05). From D1 to D3, LUS, PaO2/FiO2, APACHE-II score, and SOFA score showed a downward trend (P < 0.05). LUS was negatively correlated with PaO2/FiO2 at D1, D2, and D3 but positively correlated with APACHE-II score and SOFA score (P < 0.05). Logistic regression analysis showed that after controlling for age, PaO2 and PaCO2, an increase in baseline LUS, APACHE-II score, SOFA score, and a decrease in PaO2/FiO2 were independent risk factors for death at 28 d in ALI patients (P < 0.05). ROC curve showed that LUS, PaO2/FiO2, APACHE-II score, and SOFA score were combined to predict the prognosis of ALI patients with the highest AUC value of 0.920, corresponding sensitivity of 88.89%, and specificity of 95.56%. CONCLUSION: LUS can evaluate the change of pulmonary ventilation area in ALI patients, further evaluate the severity of the disease, and effectively predict the prognosis of patients.

Exploration of the Function of Ginsenoside RD Attenuates Lipopolysaccharide-Induced Lung Injury: A Study of Network Pharmacology and Experimental Validation.

OBJECTIVE: Ginsenoside Rd (GSRd) displays a variety of pharmacological effects. However, the underlying role in acute lung injury (ALI) is not clear. In this study, the protective effect of GSRd on lipopolysaccharide (LPS)-induced ALI is investigated to explore the potential mechanisms. METHODS: GSRd-target-ALI-related gene set was constructed. And bioinformatics tools were used to discover the potential mechanism. We observed the survival of subjects for 72 h. In addition, male BALB/c mice were intraperitoneal injected with GSRd (25 and 50 mg/kg) after received one intratracheal instillation of LPS. Inflammatory changes, oxidative stress, and phosphorylation were assessed to study the biological effects. RESULTS: A total of 245 interaction genes were collected. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were enriched in immune-inflammatory system. Among them, PI3K-Akt signaling pathway was the highest-ranked pathway of inflammatory response. In vivo study, it was found that GSRd improved survival in endotoxemic mice and inhibited the major characteristic of ALI. And the p-PI3K and p-Akt expression was significantly decreased by GSRd treatment. CONCLUSION: GSRd could protect mice against LPS-induced ALI effectively by inhibiting the PI3K-Akt signaling pathway.

Immunosuppressive effect of mesenchymal stem cells on lung and gut CD8+ T cells in lipopolysaccharide-induced acute lung injury in mice.

OBJECTIVES: Acute lung injury (ALI) not only affects pulmonary function but also leads to intestinal dysfunction, which in turn contributes to ALI. Mesenchymal stem cell (MSC) transplantation can be a potential strategy in the treatment of ALI. However, the mechanisms of synergistic regulatory effects by MSCs on the lung and intestine in ALI need more in-depth study. MATERIALS AND METHODS: We evaluated the therapeutic effects of MSCs on the murine model of lipopolysaccharide (LPS)-induced ALI through survival rate, histopathology and bronchoalveolar lavage fluid. Metagenomic sequencing was performed to assess the gut microbiota. The levels of pulmonary and intestinal inflammation and immune response were assessed by analysing cytokine expression and flow cytometry. RESULTS: Mesenchymal stem cells significantly improved the survival rate of mice with ALI, alleviated histopathological lung damage, improved intestinal barrier integrity, and reduced the levels of inflammatory cytokines in the lung and gut. Furthermore, MSCs inhibited the inflammatory response by decreasing the infiltration of CD8+ T cells in both small-intestinal lymphocytes and Peyer's patches. The gut bacterial community diversity was significantly altered by MSC transplantation. Furthermore, depletion of intestinal bacterial communities with antibiotics resulted in more severe lung and gut damages and mortality, while MSCs significantly alleviated lung injury due to their immunosuppressive effect. CONCLUSIONS: The present research indicates that MSCs attenuate lung and gut injury partly via regulation of the immune response in the lungs and intestines and gut microbiota, providing new insights into the mechanisms underlying the therapeutic effects of MSC treatment for LPS-induced ALI.

Plasma mitochondrial DNA levels are associated with acute lung injury and mortality in septic patients.

BACKGROUND: Mitochondrial DNA (mtDNA) is a critical activator of inflammation. Circulating mtDNA released causes lung injury in experimental models. We hypothesized that elevated plasma mtDNA levels are associated with acute lung injury (ALI) in septic patients. METHODS: We enrolled 66 patients with sepsis admitted to the Department of Critical Care Medicine of Peking Union Medical College Hospital between January 2019 and October 2019. Respiratory, hemodynamic and bedside echocardiographic parameters were recorded. Plasma mtDNA, procalcitonin, interleukin 6, and interleukin 8 levels were examined. RESULTS: Plasma mtDNA levels within 24 h after admission were significantly increased in the group of septic patients with ALI [5.01 (3.38-6.64) vs 4.13 (3.20-5.07) log copies/µL, p 0.0172]. mtDNA levels were independently associated with mortality (hazard ratio, 3.2052; 95% CI 1.1608-8.8500; p 0.0253) and ALI risk (odds ratio 2.7506; 95% CI 1.1647-6.4959; p 0.0210). Patients with high mtDNA levels had worse outcomes, and post hoc tests showed significant differences in 28-day survival rates. Increased mtDNA levels were seen in patients with abdominal infection. CONCLUSIONS: Increased plasma mtDNA levels within 24 h after admission were significantly associated with ALI incidence and mortality in septic patients.

Oligosaccharides from Polygonatum Cyrtonema Hua: Structural characterization and treatment of LPS-induced peritonitis in mice.

Fructooligosaccharide was isolated from Polygonatum Cyrtonema Hua (PFOS) for the first time. Structure characterized using FT-IR, MALDI-TOF-MS, NMR, AFM, and TEM, indicated that PFOS was graminan-type fructan with a degree of polymerization ranging from 5 to 10. A murine model of lipopolysaccharide (LPS)-induced peritonitis was used to evaluate the in vivo anti-inflammatory and lung protective efficacy of PFOS. The result shown that pretreatment with PFOS (1.0 mg/mL) in peritonitis-induced mice could significantly inhibit the level of pro-inflammatory cytokines (TNF-α, IL-1ß) in serum (P < 0.001), increase mice survival rate from 12.5 % to 54 % (P < 0.05), and alleviated lung injury through ameliorating the damage of the pulmonary cellular architecture and reducing inflammatory monocyte accumulation in lung tissue. This effect of oligosaccharides could explain the traditional usage of P. cyrtonema as a tonic medicine for respiratory problems and it could be used as a potential natural ingredient with anti-inflammatory activity.

GPA Peptide Attenuates Sepsis-Induced Acute Lung Injury in Mice via Inhibiting Oxidative Stress and Pyroptosis of Alveolar Macrophage.

Acute lung injury (ALI) has been known to be a devastating form of respiratory infection and an important contributor to mortality in intensive care, due to its lacking of effective treatment. Inflammation, oxidative stress, and pyroptosis are associated with multiple kinds of inflammatory diseases such as ALI. It is commonly accepted that Gly-Pro-Ala (GPA) peptide regulates oxidative stress and pyroptosis in different kinds of inflammatory diseases. Our study is aimed at exploring the regulatory function and protective effects of GPA peptides on ALI. In the current study, the cecal ligation and puncture (CLP) technique was used to evoke sepsis in mice, and GPA peptide was administered intraperitoneally with different concentrations (50, 100, and 150 mg/kg) after CLP. Histopathological changes and the ratio of wet-to-dry in lung were recorded and analyzed. We also investigated the level of oxidative stress, inflammation, and pyroptosis. Results showed that GPA peptide significantly ameliorated CLP-stimulated lung tissue injury, impeded proinflammatory cytokine release, and reduced inflammatory cell infiltration. Additionally, GPA peptide suppressed oxidative stress and caspase-1-dependent pyroptosis in alveolar macrophages. Furthermore, our study showed that the GPA peptide prevents alveolar macrophage from undergoing pyroptosis by attenuating ROS. In conclusion, results demonstrated that GPA peptide has protective effects in CLP-stimulated ALI by inhibiting oxidative stress as well as pyroptosis of alveolar macrophage.

Effectiveness and safety of intravenous tocilizumab to treat COVID-19-associated hyperinflammatory syndrome: Covizumab-6 observational cohort.

Although the starting event in COVID-19 is a viral infection some patients present with an over-exuberant inflammatory response, leading to acute lung injury (ALI) and adult respiratory distress syndrome (ARDS). Since IL-6 plays a critical role in the inflammatory response, we assessed the efficacy and safety of tocilizumab (TCZ) in this single-centre, observational study in all Covid-19 in-patient with a proven SARS-CoV-2 rapidly progressing infection to prevent ALI and ARDS. 104 patients with COVID-19 treated with TCZ had a lower mortality rate (5·8%) compared with the regional mortality rate (11%), hospitalized patient's mortality (10%), and slightly lower than hospitalized patients treated with our standard of care alone (6%). We found that TCZ rapidly decreased acute phase reactants, ferritin and liver release of proteins. D-Dimer decreased slowly. We did not observe specific safety concerns. Early administration of IL6-R antagonists in COVID-19 patients with impending hyperinflammatory response, may be safe and effective treatment to prevent, ICU admission and further complications.

A comparative study of a preclinical survival model of smoke inhalation injury in mice and rats.

Smoke inhalation injury increases morbidity and mortality. Clinically relevant animal models are necessary for the continued investigation of the pathophysiology of inhalation injury and the development of therapeutics. The goal of our research was threefold: 1) to develop a reproducible survival model of smoke inhalation injury in rats that closely resembled our previous mouse model, 2) to validate the rat smoke inhalation injury model using a variety of laboratory techniques, and 3) to compare and contrast our rat model with both the well-established mouse model and previously published rat models to highlight our improvements on smoke delivery and lung injury. Mice and rats were anesthetized, intubated, and placed in custom-built smoke chambers to passively inhale woodchip-generated smoke. Bronchoalveolar lavage fluid (BALF) and lung tissue were collected for confirmatory tests. Lung sections were hematoxylin and eosin stained, lung edema was assessed with wet-to-dry (W/D) ratio, and inflammatory cell infiltration and cytokine elevation were evaluated using flow cytometry, immunohistochemistry, and ELISA. We confirmed that our mouse and rat models of smoke inhalation injury mimic the injury seen after human burn inhalation injury with evidence of pulmonary edema, neutrophil infiltration, and inflammatory cytokine elevation. Interestingly, rats mounted a more severe immunological response compared with mice. In summary, we successfully validated a reliable and clinically translatable survival model of lung injury and immune response in rats and mice and characterized the extent of this injury. These animal models allow for the continued study of smoke inhalation pathophysiology to ultimately develop a better therapeutic.

Pulmonary complications in dogs with acute presentation of pancreatitis.

BACKGROUND: In humans, respiratory complications in patients with acute pancreatitis (AP) are a common life-threatening comorbidity. Since possible lung impairment has not been individually evaluated in canine AP, the aims of the present study were to: (1) describe the prevalence, types and severity of pulmonary complications in dogs with acute presentation of AP, and (2) evaluate their association with mortality. AP diagnosis was based on compatible clinical and laboratory parameters, abnormal canine pancreatic-lipase test, and positive abdominal ultrasound within 48 h from admission. The canine acute pancreatitis severity score (CAPS) was calculated for each dog at admission. Arterial blood gas analysis and thoracic radiography were performed at admission. Thoracic radiography was classified on the basis of pulmonary pattern (normal, interstitial or alveolar) and a modified lung injury score (mLIS) was applied to the ventrodorsal projections for each dog. VetALI/VetARDS were diagnosed using current veterinary consensus. Dogs were divided into non-survivors or survivors (hospital discharge). Clinical, radiological and blood gas parameters collected at presentation were compared between survivors and non-survivors and associated with mortality. RESULTS: This prospective cohort study included twenty-six client-owned dogs with AP. Twelve out of twenty-six dogs (46%) died or were euthanized. At admission, thirteen dogs showed respiratory distress at physical examination, which was associated with death (P < 0.001). Radiographic abnormalities were found in twenty-one dogs: alveolar (n = 11) and interstitial pattern (n = 10). Radiographic alterations and mLIS score were both associated with death (P = 0.02 and P = 0.0023). The results of the arterial blood-gas evaluation showed that non-survivors had lower PaCO2 and HCO3- levels, and higher A-a gradient than survivors (P = 0.0014, P = 0.019 and P = 0.004, respectively). Specifically, three dogs had aspiration pneumonia, and VetALI was diagnosed in nine dogs (34.6%), and no dogs met the criteria for VetARDS. The presence of VetALI was associated with mortality (P < 0.001). CONCLUSIONS: As with humans, possible lung impairments, such as VetALI, should be investigated in dogs with acute presentation of pancreatitis.

Clinical outcomes of extracorporeal membrane oxygenation in acute traumatic lung injury: a retrospective study.

BACKGROUND: Therapeutic extracorporeal membrane oxygenation (ECMO) is a challenging procedure in patients who have experienced severe trauma. Particularly, patients with traumatic lung injury and posttraumatic acute respiratory distress syndrome (ARDS) have a high risk of bleeding during this procedure. This study aimed to determine the safety and feasibility of ECMO in patients with traumatic ARDS. METHODS: We retrospectively reviewed medical records and investigated the clinical outcomes of ECMO in 42 patients with traumatic ARDS, among whom near-drowning (42.9%) was the most frequent cause of injury. RESULTS: Thirty-four of 42 patients (81%) survived and were discharged after a median hospital stay of 23 days. A multivariate analysis identified a lactate level (odds ratio: 1.493, 95% confidence interval: 1.060-2.103, P = 0.022) and veno-venous (VV) ECMO (odds ratio: 0.075, 95% confidence interval: 0.006-0.901, P = 0.041) as favorable independent predictors of survival in patients with traumatic ARDS who underwent ECMO. The optimal cut off value for pre-ECMO lactate level was 10.5 mmol/L (area under the curve = 0.929, P = 0.001). In Kaplan-Meier analysis, the survival rate at hospital discharge was significant higher among the patients with a pre-ECMO lactate level of 10.5 mmol/L or less compared with patients with pre-ECMO lactate level greater than 10.5 mmol/L (93.8% versus 40.0%, respectively; P = 0.01). CONCLUSIONS: ECMO yielded excellent survival outcomes, particularly in patients with low pre-treatment lactate levels who received VV ECMO. Therefore, ECMO appears safe and highly feasible in a carefully selected population of trauma patients.

Pituitary Adenylate Cyclase-Activating Polypeptide Prevents Mortality Caused by Septic Peritonitis in Mice.

The purpose of this study was to investigate whether pituitary adenylate cyclase-activating polypeptide (PACAP) prevents mortality due to sepsis in mice. Mice were given PACAP at designated time points before or after cecal ligation and puncture (CLP), and organ injury and mortality were investigated. Serum inflammatory and anti-inflammatory cytokine levels were assessed after CLP. Plasma corticosterone and adrenocorticotropic hormone levels were also measured. Isolated tissue macrophages (Mfs) were incubated with or without PACAP, and production of cytokines was measured. Activation of NF-κB was investigated in tissue Mfs isolated from CLP animal in the presence and absence PACAP in vitro. PACAP treatment significantly prevented acute lung injury and mortality after CLP. Plasma endotoxin levels and bacterial load were not different between PACAP-treated and nontreated groups. Increased serum TNF-α and HMGB1 levels in animals treated with vehicle were significantly blunted in PACAP-treated animals after CLP. Furthermore, serum IL-10 levels were significantly greater in the PACAP-treated group compared with the vehicle group. Production of HMGB1 and TNF-α by isolated hepatic Mfs was significantly inhibited in the presence of PACAP, whereas production of IL-10 by isolated hepatic Mfs and interstitial lung Mfs was significantly increased. Plasma corticosterone and adrenocorticotropic hormone levels were significantly greater in the animals treated with PACAP compared with vehicle after CLP. Activation of NF-κB was significantly inhibited by PACAP in the hepatic Mfs compared with other tissue Mfs. PACAP prevents mortality due to septic peritonitis by inhibiting inflammation via NF-κB activation and possible effects on the brain.

Lonicerin prevents inflammation and apoptosis in LPS-induced acute lung injury.

Acute lung injury (ALI) is a life-threatening condition caused by severe inflammation of lung tissues. We hypothesized that lipopolysaccharide induced acute lung inflammation and injury in mice might be controlled by lonicerin (LCR), a plant flavonoid that impacts immunity, oxidative stress, and cell proliferation. LCR reduced pathological changes including pulmonary edema, elevation of protein in bronchoalveolar lavage, inflammation, pro-inflammatory gene expression, expression of toll-like receptor 4/nuclear factor-kappa B, apoptosis, and significantly reduced mortality. Together, the results suggest that LCR might be a potential and effective candidate for the treatment of ALI that acts by inhibiting inflammation and apoptosis.

Oxytocin maintains lung histological and functional integrity to confer protection in heat stroke.

Oxytocin (OT) has been reported to have a protective effect in lipopolysaccharide-induced experimental acute lung injury (ALI). However, its role in heat stroke-related ALI has never been investigated. Herein, we aimed to explore the therapeutic effects and potential mechanism of action of OT on heat-induced ALI. Rats were treated with OT 60 min before the start of heat stress (42 °C for 80 min). Twenty minutes after the termination of heat stress, the effects of OT on lung histopathological changes, edema, acute pleurisy and the bronchoalveolar fluid levels of inflammatory cytokines and indicators of ischemia, cellular damage, and oxidative damage were assessed. We also evaluated the influence of OT pretreatment on heat-induced hypotension, hyperthermia, ALI score, and death in a rat model of heat stroke. The results showed that OT significantly reduced heat-induced lung edema, neutrophil infiltration, hemorrhage score, myeloperoxidase activity, ischemia, and the levels of inflammatory and oxidative damage markers in bronchoalveolar lavage fluid. The survival assessment confirmed the pathophysiological and biochemical results. An OT receptor antagonist (L-368,899) was administered 10 min before the OT injection to further demonstrate the role of OT in heat-induced ALI. The results showed that OT could not protect against the aforementioned heat stroke responses in rats treated with L-368,899. Interestingly, OT treatment 80 min after the start of heat shock did not affect survival. In conclusion, our data indicate that OT pretreatment can reduce the ischemic, inflammatory and oxidative responses related to heat-induced ALI in rats.

Challenges and perspectives in porcine model of acute lung injury using oleic acid.

The oleic acid (OA) models of lung injury try to simulate the findings of human Acute Respiratory Distress Syndrome (ARDS). However, these models are difficult to replicate because they vary in terms of animals species, OA doses, time for establishment of lung injury, different observation periods and settings of mechanical ventilation. The objective of this study was to evaluate a protocol of administration of OA in lung injury model, challenges in its development and its effects on respiratory mechanics, hemodynamic changes, histology, gas exchange and mortality. We then submitted ten Large White pigs to acute lung injury through intravenous infusion of acid oleic in the pulmonary artery. The mortality of the model was 50%, due to an intense hemodynamic instability during OA administration, even with early use of vasoactive drugs. Three animals required additional doses of OA to achieve criteria for acute lung injury. Histology showed findings consistent with acute lung injury. However, more pulmonary edema was observed in lower segments than in upper segments of both lungs (p = 0.01). IL-6 and IL-8 were significantly increased compared to normal lungs (p < 0.05), and IL-6 showed higher levels in upper segments compared to lower segments (p = 0.03). Positive cells for Caspase 3 were present in all samples, localized mainly in respiratory epithelial cells and macrophages. In conclusion, this model shows histological findings of acute lung injury and inflammatory response similar to those of clinical ARDS, it presents high mortality, inconsistent reproducibility and hardly controlled hemodynamic instability.

Emodin reactivated autophagy and alleviated inflammatory lung injury in mice with lethal endotoxemia.

An uncontrolled inflammation induced critical health problems with serious morbidity and death, which namely acute lung injury (ALI). Recently researchs have found the anti-inflammatory effects of emodin. Here, we investigated the potential effects of emodin on a mouse model with a lethal dose of the potential mechanisms and lipopolysaccharide (LPS)-induced inflammatory lung injury in mice. The pulmonary histological abnormalities, the Evans blue's leakage, the myeloperoxidase (MPO) activity, the grades of TNF-α, IL-6, nitric oxide (NO), lactic acid (LA) in lung tissues were determined 18 h post exposure of LPS. Based on the expression of LC3-II with BECN1 was determined using Western blotting. Besides, the LPS-exposed mice for survival rate was monitored. The results indicated that intervention with emodin was important for mitigating LPS-induced pulmonary histological change and LPS-induced leakage of Evans blue, which were associated with suppressed elevation of MPO activity and inhibited up-regulation of TNF-α, IL-6, NO with LA in lung tissues. Moreover, intervention with emodin enhanced the survival rate of LPS-exposed mice. Finally, therapy with emodin increased the LC3 and BECN1 in lungs of LPS-exposed mice. Treatment with 3-MA (the autophagy inhibitor) reversed the beneficial effects of emodin. In conclusion, emodin might provide pharmacological benefits in LPS-induced inflammatory lung injury, and the mechanisms might be related to the restoration of autophagy.

Innovative in vitro method to study ventilator induced lung injury.

Mechanical ventilation (MV) is a life-saving therapy for critically ill patients, alleviating the work of breathing and supporting adequate gas exchange. However, MV can cause ventilator induced lung injury (VILI) by baro/volu- and atelectrauma, even lead to acute respiratory distress syndrome (ARDS), and substantially augment mortality. There is a need for specific biomarkers and novel research platforms for VILI/ARDS research to study these detrimental disorders and seek ways to avoid or prevent them. Previous in vitro studies on bronchial epithelium, cultured in air-liquid interface (ALI) conditions, have generally utilized static or constant pressure.  We have developed a Cyclical Pressure ALI Device (CPAD) that enables cyclical stress on ALI cultured human bronchial cells, with the aim of mimicking the effects of MV. Using CPAD we were able to analyze differentially expressed VILI/ARDS and innate immunity associated genes along with increased expression of associated proteins. CPAD provides an easy and accessible way to analyze functional and phenotypic changes that occur during VILI and may provide a platform for future drug testing.

A Peptide Inhibitor of NADPH Oxidase (NOX2) Activation Markedly Decreases Mouse Lung Injury and Mortality Following Administration of Lipopolysaccharide (LPS).

We have previously derived three related peptides, based on a nine-amino acid sequence in human or rat/mouse surfactant protein A, that inhibit the phospholipase A2 activity of peroxiredoxin 6 (Prdx6) and prevent the activation of lung NADPH oxidase (type 2). The present study evaluated the effect of these Prdx6-inhibitory peptides (PIP) in a mouse (C57Bl/6) model of acute lung injury following lipopolysaccharide (LPS) administration. All three peptides (PIP-1, 2 and 3) similarly inhibited the production of reactive O2 species (ROS) in isolated mouse lungs as detected by the oxidation of Amplex red. PIP-2 inhibited both the increased phospholipase A2 activity of Prdx6 and lung reactive oxygen species (ROS) production following treatment of mice with intratracheal LPS (5 µg/g body wt.). Pre-treatment of mice with PIP-2 prevented LPS-mediated lung injury while treatment with PIP-2 at 12 or 16 h after LPS administration led to reversal of lung injury when evaluated 12 or 8 h later, respectively. With a higher dose of LPS (15 µg/g body wt.), mortality was 100% at 48 h in untreated mice but only 28% in mice that were treated at 12-24 h intervals, with PIP-2 beginning at 12 h after LPS administration. Treatment with PIP-2 also markedly decreased mortality after intraperitoneal LPS (15 µg/g body wt.), used as a model of sepsis. This study shows the dramatic effectiveness of a peptide inhibitor of Prdx6 against lung injury and mouse mortality in LPS models. We propose that the PIP nonapeptides may be a useful modality to prevent or to treat human ALI.