The pulmonary physician in critical care. 5: Acute lung injury and the acute respiratory distress syndrome: definitions and epidemiology

Evaluation of the effect of enriched hydrogen saline solution on distant organ (lung) damage in skeletal muscle ischemia reperfusion in rats

INTRODUCTION

Ischemia-reperfusion (IR) injury is a major concern that frequently occurs during vascular surgeries. Hydrogen-rich saline (HRS) solution exhibits antioxidant and anti-inflammatory properties. This study aimed to examine the effects of HRS applied before ischemia in the lungs of rats using a lower extremity IR model.

MATERIAL AND METHODS

After approval was obtained from the ethics committee, 18 male Wistar albino rats weighing 250-280 g were randomly divided into three groups: control (C), IR and IR-HRS. In the IR and IR-HRS groups, an atraumatic microvascular clamp was used to clamp the infrarenal abdominal aorta, and skeletal muscle ischemia was induced. After 120 min, the clamp was removed, and reperfusion was achieved for 120 min. In the IR-HRS group, HRS was administered intraperitoneally 30 min before the procedure. Lung tissue samples were examined under a light microscope and stained with hematoxylin-eosin (H&E). Malondialdehyde (MDA) levels, total sulfhydryl (SH) levels, and histopathological parameters were evaluated in the tissue samples.

RESULTS

MDA and total SH levels were significantly higher in the IR group than in the control group (p < 0.0001 and p = 0.001, respectively). MDA and total SH levels were significantly lower in the IR-HRS group than in the IR group (p < 0.0001 and p = 0.013, respectively). A histopathological examination revealed that neutrophil infiltration/aggregation, alveolar wall thickness, and total lung injury score were significantly higher in the IR group than in the control group (p < 0.0001, p = 0.001, and p < 0.0001, respectively). Similarly, alveolar wall thickness and total lung injury scores were significantly higher in the IR-HRS group than in the control group (p = 0.009 and p = 0.004, respectively). A statistically significant decrease was observed in neutrophil infiltration/aggregation and total lung injury scores in the IR-HRS group compared to those in the IR group (p = 0.023 and p = 0.022, respectively).

CONCLUSION

HRS at a dose of 20 mg/kg, administered intraperitoneally 30 min before ischemia in rats, reduced lipid peroxidation and oxidative stress, while also reducing IR damage in lung histopathology. We believe that HRS administered to rats prior to IR exerts a lung-protective effect.

Synthesis and structure-activity relationship studies of fusidic acid derivatives as anti-inflammatory agents for acute lung injury

Acute lung injury (ALI) are severe forms of diffuse lung disease that impose a substantial health burden all over the world. In the United States, approximately 190,000 cases per year of ALI each year, with an associated 74,500 deaths per year. Anti-inflammatory therapy has become a reasonable approach for the treatment of patients with ALI. In this study, fusidic acid derivatives were used to design new anti-inflammatory compounds with high pharmacological activity and low toxicity. A total of 30 new fusidic acid derivatives were discovered, synthesized, and screened for their anti-inflammatory activity against lipopolysaccharide (LPS)-treated RAW264.7 cells. Of them, b2 was found to be the most active, with a higher efficiency compared with fusidic acid and celecoxib in 10 μM. In vitro, we further measured b2 inhibited inflammatory factor NO (IC50 = 5.382 ± 0.655 μM), IL-6 (IC50 = 7.767 ± 0.871 μM), and TNF-α (IC50 = 7.089 ± 0.775 μM) and b2 inhibited inflammatory cytokines COX-2 and iNOS, ROS production, NF-κB/MAPK and Bax/Bcl-2 signaling pathway pathway. In vivo,b2 attenuated ALI pathological changes and inhibited inflammatory cytokines COX-2 and iNOS in lung tissue and NF-κB/MAPK and Bax/Bcl-2 signaling pathway. In conclusion, b2 may be a promising anti-inflammatory lead compound.

Network pharmacology and in vivo and in vitro experiments to determine the mechanism behind the effects of Jiawei Yanghe decoction via TLR4/Myd88/NF-κB against mastitis

Background

In the Qing dynasty, Yanghe decoction was as a therapeutic soup for effectively treating chronic inflammatory disorders. It was used as a therapeutic soup for effectively treating chronic inflammatory disorders. In the clinical use of Yanghe decoction, the adjustment of the medication for a variety of inflammatory diseases have therapeutic effect, including mastitis. Therefore, Jiawei Yanghe decoction (JWYHD) may be used to treat inflammatory breast diseases.

Methods

First, LM- and JWYHD-related components were retrieved from the database and analysis platform. Next, protein-protein interaction networks were constructed to screen the key targets, and gene ontology and Kyoto encyclopedia of gene and genome enrichment analyses were performed to predict the potential biological functions and mechanisms of JWYHD. Simultaneously, the JWYHD samples were collected and analyzed by UPLC-HRMS. Finally, in vivo and in vitro experiments were conducted to construct animal and cellular inflammation models of mastitis with LPS. Pathological changes in the mammary tissues were detected. Enzyme-linked immunosorbent assay, reverse transcription-polymerase chain reaction, and Western blotting was performed to determine the mRNA and protein levels of inflammatory cytokines and toll-like receptor 4/myeloid differentiation primary response 88/nuclear factor kappa B signaling pathway in the breast tissues to elucidate the potential underlying mechanisms of anti-mastitis effects of JWYHD from different aspects.

Results

In total, 103 compounds were detected in JWYHD by UPLC-HRMS. 691 active ingredients of JWYHD were screened by network pharmacology, and 47 LM-related targets were identified. The PPI network analysis of the targets revealed the 5 core targets. The KEGG enrichment results established the NF-κB signaling pathways as the core. After JWYHD intervention, low inflammatory enrichment and mild inflammatory damage in breast tissues were observed. Furthermore, JWYHD treatment affected mammary gland inflammatory cytokines and the TLR4/Myd88/NF-κB signaling pathway by considerably reducing the respective protein levels and gene expression; thus, JWYHD alleviated LM symptoms.

Conclusions

We hypothesized and demonstrated the anti-inflammatory effects of JWYHD by cytokine regulation via the TLR4/Myd88/NF-κB signaling pathway. In conclusion, JWYHD showed its potential in LM treatment and in treating other acute and chronic inflammatory diseases.

Intravascular laser irradiation of blood (ILIB) used to treat lung diseases: a short critical review

Intravascular laser irradiation of blood (ILIB) was developed to treat cardiovascular diseases due to its rheological effects. In its original form, ILIB was applied by an intravenous optical fiber, restricting its application. However, this technique was modified to non-invasive irradiation through the radial artery, now called vascular photobiomodulation (VPBM). Many studies have used both, ILIB and VPBM, to treat lung diseases. It is well established that lung diseases affect more than 300 million people worldwide with high morbidity and mortality rates. In this short critical review, we discuss the potential benefits of photobiomodulation to treat lung diseases using these two approaches. The search was performed in the electronic database of MEDLINE (Medical Literature Analysis and Retrieval System Online) via PubMed. The data search was carried out from 1991 to 2017. We selected a total of 10 clinical studies using either ILIB or VPBM, in addition to 2 experimental studies in animals. The respiratory diseases treated in these studies included bronchitis, asthma, pneumonia, and tuberculosis. The results showed overall beneficial effects on lung diseases, characterized by a reduction in the inflammatory cascade and antioxidant effects, improvement of hemodynamic parameters, the efficiency of gas exchange, and reduction of hospitalization periods. In conclusion, all studies showed promising effects of ILIB in both animal and human studies. The studies did not discuss any disadvantages or contraindications. However, further studies are needed in order to understand the dosimetry, and the literature is lacking in randomized, controlled clinical trials. Thus, this review highlights the need for additional studies using this approach.

Small extracellular vesicles derived from Nrf2-overexpressing human amniotic mesenchymal stem cells protect against lipopolysaccharide-induced acute lung injury by inhibiting NLRP3

BACKGROUND

Acute lung injury (ALI) is a major cause of respiratory failure in critically ill patients that results in significant morbidity and mortality. Recent studies indicate that cell-based therapies may be beneficial in the treatment of ALI. We recently demonstrated that Nrf2-overexpressing human amniotic mesenchymal stem cells (hAMSCs) reduce lung injury, fibrosis and inflammation in lipopolysaccharide (LPS)-challenged mice. Here we tested whether small extracellular vesicles (sEVs) derived from Nrf2-overexpressing hAMSCs (Nrf2-sEVs) could protect against ALI. sEVs were isolated from hAMSCs that overexpressed (Nrf2-sEVs) or silenced (siNrf2-sEVs) Nrf2. We examined the effects of sEVs treatment on lung inflammation in a mouse model of ALI, where LPS was administered intratracheally to mice, and lung tissues and bronchoalveolar lavage fluid (BALF) were analyzed 24 h later.

METHODS

Histological analysis, immunofluorescence microscopy, western blotting, RT-PCR and ELISA were used to measure the inflammatory response in the lungs and BALF.

RESULTS

We found that sEVs from hAMSCs are protective in ALI and that Nrf2 overexpression promotes protection against lung disease. Nrf2-sEVs significantly reduced lung injury in LPS-challenged mice, which was associated with decreased apoptosis, reduced infiltration of neutrophils and macrophages, and inhibition of pro-inflammatory cytokine expression. We further show that Nrf2-sEVs act by inhibiting the activation of the NLRP3 inflammasome and promoting the polarization of M2 macrophages.

CONCLUSION

Our data show that overexpression of Nrf2 protects against LPS-induced lung injury, and indicate that a novel therapeutic strategy using Nrf2-sEVs may be beneficial against ALI.

Effects of aerobic exercise on lipopolysaccharide-induced experimental acute lung injury in the animal model of type 1 diabetes mellitus

NEW FINDINGS

What is the central question of this study? We evaluated the effects of diabetes and exercise on lipopolysaccharide-induced acute lung injury. By providing a comprehensive analysis of redox status, blood gases and histological parameters, we aimed to contribute to the ongoing debate in the literature. What are the main findings and its importance? We demonstrated the preventive effect of exercise, but diabetes did not alter the severity of acute lung injury.

ABSTRACT

Acute lung injury (ALI) is a life-threatening respiratory condition. Diabetes (DM) is a metabolic disease characterized by hyperglycaemia. There is an ongoing debate concerning whether there is a protective effect of diabetes in ALI. Exercise is a special type of physical activity that has numerous beneficial effects. The aim of our study was to investigate the effects of diabetes and exercise on the prognosis of ALI. Male Wistar albino rats were divided into two groups (sedentary and exercise). Both groups were divided into four subgroups: Control, ALI, DM, DM+ALI (n = 6 each). Diabetes was induced by injection of streptozotocin (50 mg/kg i.p.). The maximal exercise capacity was determined with the incremental load test. Animals were exercised on a treadmill for 45 min at 70% of maximal exercise capacity, 5 days a week for 12 weeks. Acute lung injury was induced by intratracheal injection of lipopolysaccharide (100 μg/100 g body weight) 24 h before the end of the experiment. We performed arterial blood gas analysis. Redox status was measured in both plasma and lung tissue. Malondialdehyde and 8-hydroxy-2'-deoxyguanosine levels were measured in lung tissue. Lung tissue was evaluated histologically. Acute lung injury caused significant damage in the lung tissue, which was verified histologically, with an increase in oxidative stress parameters. Exercise prevented the lung damage induced by ALI and reduced oxidative stress in the lung tissue. Diabetes did not alter the magnitude of damage done by ALI. Exercise showed a protective effect against DM and ALI in rats. The effect of DM was insignificant for the prognosis of ALI.

Inorganic polyphosphate from the immunobiotic Lactobacillus rhamnosus CRL1505 prevents inflammatory response in the respiratory tract

Lactobacillus (L.) rhamnosus CRL1505 accumulates inorganic polyphosphate (polyP) in its cytoplasm in response to environmental stress. The aim of this study was to evaluate the potential effects of polyP from the immunobiotic CRL1505 on an acute respiratory inflammation murine animal model induced by lipopolysaccharide (LPS).

First, the presence of polyP granules in the cytoplasm of CRL1505 strain was evidenced by specific staining. Then, it was demonstrated in the intracellular extracts (ICE) of CRL1505 that polyP chain length is greater than 45 phosphate residues. In addition, the functionality of the genes involved in the polyP metabolism (ppk, ppx1 and ppx2) was corroborated by RT-PCR. Finally, the possible effect of the ICE of CRL1505 strain containing polyP and a synthetic polyP was evaluated in vivo using a murine model of acute lung inflammation. It was observed that the level of cytokines pro-inflammatory (IL-17, IL-6, IL-2, IL-4, INF-γ) in serum was normalized in mice treated with ICE, which would indicate that polyP prevents the local inflammatory response in the respiratory tract. The potential application of ICE from L. rhamnosus CRL1505 as a novel bioproduct for the treatment of respiratory diseases is one of the projections of this work.

Cryoprecipitate attenuates the endotheliopathy of trauma in mice subjected to hemorrhagic shock and trauma

BACKGROUND

Plasma has been shown to mitigate the endotheliopathy of trauma. Protection of the endothelium may be due in part to fibrinogen and other plasma-derived proteins found in cryoprecipitate; however, the exact mechanisms remain unknown. Clinical trials are underway investigating early cryoprecipitate administration in trauma. In this study, we hypothesize that cryoprecipitate will inhibit endothelial cell (EC) permeability in vitro and will replicate the ability of plasma to attenuate pulmonary vascular permeability and inflammation induced by hemorrhagic shock and trauma (HS/T) in mice.

METHODS

In vitro, barrier permeability of ECs subjected to thrombin challenge was measured by transendothelial electrical resistance. In vivo, using an established mouse model of HS/T, we compared pulmonary vascular permeability among mice resuscitated with (1) lactated Ringer's solution (LR), (2) fresh frozen plasma (FFP), or (3) cryoprecipitate. Lung tissue from the mice in all groups was analyzed for markers of vascular integrity, inflammation, and inflammatory gene expression via NanoString messenger RNA quantification.

RESULTS

Cryoprecipitate attenuates EC permeability and EC junctional compromise induced by thrombin in vitro in a dose-dependent fashion. In vivo, resuscitation of HS/T mice with either FFP or cryoprecipitate attenuates pulmonary vascular permeability (sham, 297 ± 155; LR, 848 ± 331; FFP, 379 ± 275; cryoprecipitate, 405 ± 207; p < 0.01, sham vs. LR; p < 0.01, LR vs. FFP; and p < 0.05, LR vs. cryoprecipitate). Lungs from cryoprecipitate- and FFP-treated mice demonstrate decreased lung injury, decreased infiltration of neutrophils and activation of macrophages, and preserved pericyte-endothelial interaction compared with LR-treated mice. Gene analysis of lung tissue from cryoprecipitate- and FFP-treated mice demonstrates decreased inflammatory gene expression, in particular, IL-1β and NLRP3, compared with LR-treated mice.

CONCLUSION

Our data suggest that cryoprecipitate attenuates the endotheliopathy of trauma in HS/T similar to FFP. Further investigation is warranted on active components and their mechanisms of action.

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

Acute 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.

Can Coagulation System Disorders and Cytokine and Inflammatory Marker Levels Predict the Temporary Clinical Deterioration or Improvement of Septic Patients on ICU Admission?

Although coagulation disorders and immune/inflammatory response have been associated with the final outcome of patients with sepsis, their link with thetemporaryclinical deterioration or improvement of patients is unknown. We aimed to investigate this link. We prospectively included consecutive patients admitted to the intensive care unit (ICU) with a suspected diagnosis of infection and evaluated within the first 24 h from admission. Blood levels of many cytokines and inflammatory and coagulation factors were measured and their predictive value was assessed by calculating the Area Under the Receiver Operating Characteristic (AUROC) curves. Patients (n = 102) were allocated in five groups, i.e., sepsis (n = 14), severe sepsis (n = 17), septic shock (n = 28), Systemic Inflammatory Response Syndrome (SIRS) without infection (n = 17), and trauma/surgery without SIRS or infection (n = 26). In septic shock, coagulation factors FVII and FIX and Protein C had AUROCs 0.67-0.78. In severe sepsis, Antithrombin III, Protein C, C-reactive protein, Procalcitonin and Thrombopoietin had AUROCs 0.73-0.75. In sepsis, Tumor Necrosis Factor a, and Interleukins 1β and 10 had AUROCs 0.66-0.72. In patients admitted to the ICU with a suspected diagnosis of infection, coagulation factors and inhibitors, as well as cytokine and inflammatory marker levels, have substantial predictive value in distinct groups of septic patients.

Overview of Research Development on the Role of NF-κB Signaling in Mastitis

Mastitis is the inflammation of the mammary gland. Escherichia coli and Staphylococcus aureus are the most common bacteria responsible for mastitis. When mammary epithelial cells are infected by microorganisms, this activates an inflammatory response. The bacterial infection is recognized by innate pattern recognition receptors (PRRs) in the mammary epithelial cells, with the help of Toll-like receptors (TLRs). Upon activation by lipopolysaccharides, a virulent agent of bacteria, the TLRs further trigger nuclear factor-κB (NF-κB) signaling to accelerate its pathogenesis. The NF-κB has an essential role in many biological processes, such as cell survival, immune response, inflammation and development. Therefore, the NF-κB signaling triggered by the TLRs then regulates the transcriptional expression of specific inflammatory mediators to initiate inflammation of the mammary epithelial cells. Thus, any aberrant regulation of NF-κB signaling may lead to many inflammatory diseases, including mastitis. Hence, the inhibiting of NF-κB signaling has potential therapeutic applications in mastitis control strategies. In this review, we highlighted the regulation and function of NF-κB signaling in mastitis. Furthermore, the role of NF-κB signaling for therapeutic purposes in mastitis control has been explored in the current review.

Dexmedetomidine protects against lung injury induced by limb ischemia-reperfusion via the TLR4/MyD88/NF-κB pathway

Dexmedetomidine (DEX) can protect the lung from ischemia-reperfusion (I/R) injury, but the underlying mechanisms are not fully understood. The aims of this study were to determine whether DEX attenuates lung injury following lower extremity I/R and to investigate the related toll-like receptor 4 (TLR4) signaling pathway. Twenty-eight SD rats were divided into four groups (n = 7): Sham, I/R, I/R + DEX (25 μg/kg prior to ischemia), and I/R + DEX + Atip (250 μg/kg atipamezole before DEX treatment). Lower extremity I/R was induced by left femoral artery clamping for 3 hours and followed by 2 hours reperfusion. Quantitative alveolar damage and the wet/dry (W/D) ratio were calculated. Interleukin (IL)-1, IL-6, and tumor necrosis factor (TNF)-α in the bronchoalveolar lavage fluid (BALF) and serum and myeloperoxidase (MPO) in the lung were measured. The TLR4 and MyD88 mRNA expression levels were measured by RT-PCR, nuclear factor (NF)-κB, and phosphorylated NF-κB by western blot, respectively. Quantitative alveolar damage, W/D ratio, MPO, BALF and serum IL-1, IL-6, and TNF-α, and TLR4, MyD88, NF-κB, and p-NF-κB expression significantly increased in the I/R group relative to the Sham group. DEX preconditioning significantly reduced lung edema, and histological injury relative to the I/R group. Serum and BALF IL-1, IL-6, and TNF-α levels, MPO activity and TLR4, MyD88, NF-κB, and p-NF-κB expression were also significantly reduced in the I/R + DEX group compared with the I/R group. Atipamezole partially reversed all the aforementioned effects. DEX preconditioning protects the lungs against lower extremity I/R injury via α2-adrenoceptor-dependent and α2-adrenoceptor-independent mechanisms. It also suppresses the TLR4 pathway and reduces inflammation.

Umbelliferone Alleviates Lipopolysaccharide-Induced Inflammatory Responses in Acute Lung Injury by Down-Regulating TLR4/MyD88/NF-κB Signaling

This study investigated the protective effect and underlying mechanism of action of umbelliferone (Umb) against lipopolysaccharide (LPS)-induced acute lung injury (ALI). An intragastric Umb injection prior to the administration of LPS dramatically decreased the wet/dry lung weight ratio, attenuated inflammatory cell infiltration in lung tissue, and reduced the LPS-induced production of inflammatory cytokines, including monocyte chemotactic protein-1(MCP-1), interleukin (IL)-6, tumor necrosis factor-α (TNF-α), and IL-1β, in broncheoalveolar lavage fluid (BALF). In addition, Umb resulted in significant anti-oxidative effects as shown by decreased myeloperoxidase (MPO) and malondialdehyde (MDA) activity and increased superoxide dismutase (SOD) activity compared with the LPS group. Finally, the inhibitory effects of Umb on the expression of toll-like receptor 4 (TLR4)/myeloid differentiation protein 88 (MyD88)/nuclear factor-κB (NF-κB) signaling pathway proteins were also measured. Our results clearly indicated that Umb exerted significant protective effects on LPS-induced ALI by inhibiting the activation of the TLR4/MyD88/NF-κB pathway.

Ventilatory pattern variability as a biometric for severity of acute lung injury in rats

We hypothesize that ventilatory pattern variability (VPV) varies with the magnitude of acute lung injury (ALI). In adult male rats, we instilled a low- or high- dose of bleomycin or saline (PBS) intratracheally. While representative samples of pulmonary tissue indicated graded lung injury, coefficient of variation (CV) of TTOT did not differ among the 3 groups. Broncho-alveolar lavage fluid (BALF), respiratory rate (fR), mutual information were greater in ALI than sham rats; but did not differ between bleomycin doses. However, nonlinear complexity index (NLCI), which is the difference in sample entropy between original and surrogate data sets was greater for high- versus low- dose; but did not differ between low-dose and sham groups. Further, NLCI correlated to an injury index based on protein concentration of BALF and failure to gain weight. Finally, Receiver Operator Curves (ROCs) indicated that both mutual information and NLCI had greater sensitivity and specificity than fR and CVTTOT in identifying ALI. Thus, nonlinear analyses of VPV can distinguish ALI and out performs fR as a biometric.

Glycyrrhizic acid ameliorates LPS-induced acute lung injury by regulating autophagy through the PI3K/AKT/mTOR pathway

Acute lung injury (ALI) is a major pathological issue characterized by serious inflammatory response, and a major clinically critical illness with high morbidity and mortality. Glycyrrhizic acid (GA) is a major bioactive constituent isolated from traditional Chinese herb licorice, which has been reported to have positive effects on inflammation. Nevertheless, the effects of GA on lipopolysaccharide (LPS)-treated ALI in mice have not been reported. The purpose of our study is to investigate the inhibitory effects of GA on ALI treated by LPS and to elucidate its possible mechanisms. We found that GA significantly attenuated lung injury and decreased the production of inflammatory factors TNF-α, IL-1β, and HMGB1 with LPS treatment. GA induced autophagy which was showed by enhanced number of autophagosomes through upregulating the protein levels of LC3-II/I and Beclin-1 and downregulating SQSTM1/P62. Moreover, pre-treatment of 3-Methyladenine (3-MA), an autophagy inhibitor, reversed the inhibiting effects of GA on the secretion of inflammatory factors in ALI. The PI3K/AKT/mTOR pathway was associated with GA-induced autophagy under ALI induced by LPS. In conclusion, this study indicated that GA inhibited the production of inflammatory factors in LPS-induced ALI by regulating the PI3K/AKT/mTOR pathway related autophagy, which may provide a novel therapeutic perspective of GA in ameliorating ALI.

Prevalence and Risk Factors of Hypoxemia after Coronary Artery Bypass Grafting: The Time to Change Our Conceptions

Background: Acute hypoxemia is the main characteristic of acute respiratory distress syndrome (ARDS), which is one of the most critical complications of coronary artery bypass grafting (CABG). Given the dearth of data on acute hypoxemia, we sought to determine its prevalence and risk factors among post-CABG patients. Methods: This cross-sectional study was conducted on on-pump CABG patients in Tehran Heart Center in 2 consecutive months in 2012. The effects of arterial blood gas variables, age, gender, the duration of the pump and cross-clamping, the ejection fraction, the creatinine level, and the body mass index on the prevalence of hypoxemia at the cutoff points of ARDS and acute lung injury were assessed. Results: Out of a total of 232 patients who remained in the study, 174 (75.0%) cases were male. The mean age was 60.60±9.42 years, and the mean body mass index was 27.15±3.93 kg/m². None of the patients expired during the current admission. The ratio of partial pressure arterial oxygen to the fraction of inspired oxygen (PaO₂/FiO₂) 1 hour after admission to the intensive care unit (ICU), before extubation, and at 4 hours after extubation was less than 300 mmHg in 66.6%, 72.2%, and 86.6% of the patients and less than 200 mmHg in 20.8% 17.7%, and 30.2% of the patients, respectively. Among the different variables, only a heavier weight was associated with a PaO₂/FiO₂ ratio of less than 300 mmHg at 1 hour after ICU admission and at 4 hours after extubation (P=0.001). A rise in the cross-clamp time showed a significant association with the risk of a PaO₂/FiO₂ ratio of less than 200 mmHg at 4 hours after extubation (P=0.014). Conclusion: This study shows that hypoxemia following CABG is very common in the first 48 postoperative hours, although it is a benign and transient event. The high prevalence may affect the accuracy of the ARDS criteria and their positive or negative predictive value.

Predictors of Initial Smear-Negative Active Pulmonary Tuberculosis with Acute Early Stage Lung Injury by High-Resolution Computed Tomography and Clinical Manifestations: An Auxiliary Model in Critical Patients

This study evaluated the diagnostic use of high-resolution computed tomography (HRCT), chest X-ray (CXR), and clinical manifestations (CM) to identify initial smear-negative (iSN) active pulmonary tuberculosis (aPTB) [iSN-aPTB] in patients with iSN-pulmonary diseases (PD) and acute lung injury (ALI). In the derivation cohort, the [iSN-PD] with ALI patients were divided into the [iSN-aPTB] (G1, n = 26) and [non-aPTB-PD] (G2, n = 233) groups. Lung morphology, number, and lobar (segmental) distribution were evaluated using CXR and HRCT. A multivariate analysis was performed to identify independent variables associated with G1, which were used to generate predictive score models for G1. The predictive model was validated in a separate population of patients (n = 372) with [iSN-PD] and (ALI). The validated model for [HRCT (CXR + Hypoalbuminemia)] had 93.5% (25.8%) sensitivity, 99.5% (89.4%) specificity, and a negative predictive value of 99.5% (93.0%). For [iSN-aPTB], the post-test probability in the derivation cohort (prevalence = 10%), validation cohort (prevalence = 8.3%), and the given prevalence (prevalence = 1%) was 88.7%, 94.4%, and 41.5%, respectively. The HRCT model effectively identified the [iSN-aPTB] subjects among the [iSN-PD] with ALI, regardless of CM. The [non-aPTB-PD] were also correctly classified by the HRCT and [CXR + Hypoalbuminemia] models.

Identification of Key Metabolites for Acute Lung Injury in Patients with Sepsis

BACKGROUND

The study aimed to detect critical metabolites in acute lung injury (ALI).

METHODS

A comparative analysis of microarray profile of patients with sepsis-induced ALI compared with sepsis patients with was conducted using bioinformatic tools through constructing multi-omics network. Multi-omics composite networks (gene network, metabolite network, phenotype network, gene-metabolite association network, phenotype-gene association network, and phenotype-metabolite association network) were constructed, following by integration of these composite networks to establish a heterogeneous network. Next, seed genes, and ALI phenotype were mapped into the heterogeneous network to further obtain a weighted composite network. Random walk with restart (RWR) was used for the weighted composite network to extract and prioritize the metabolites. On the basis of the distance proximity among metabolites, the top 50 metabolites with the highest proximity were identified, and the top 100 co-expressed genes interacted with the top 50 metabolites were also screened out.

RESULTS

Totally, there were 9363 nodes and 10,226,148 edges in the integrated composite network. There were 4 metabolites with the scores > 0.009, including CHITIN, Tretinoin, sodium ion, and Celebrex. Adenosine 5'-diphosphate, triphosadenine, and tretinoin had higher degrees in the composite network and the co-expressed network.

CONCLUSION

Adenosine 5'-diphosphate, triphosadenine, and tretinoin may be potential biomarkers for diagnosis and treatment of ALI.

Corilagin protects the acute lung injury by ameliorating the apoptosis pathway

This study elucidates the protective effect of corilagin in acute lung injury rat model. Lung injury induced by ischemia/reperfusion (I/R) model was established by isolating the lungs from the rats. Ischemia was produced for the duration of 1h and thereafter reperfusion was done for 90min in isolated lung in presence and absence of corilagin (20 and 40mg/ml). Effect of corilagin was evaluated by estimating the pulmonary vein oxygen partial pressure (PaO2), airway compliance and tidal volume. Moreover the level of oxidative stress parameter, pro inflammatory parameters, phosphorylation of JNK and apoptosis rate was estimated in lung tissues. There was significant increase in the PaO2, airway compliance and tidal volume in corilagin treated group than I/R group. Treatment with corilagin significantly increases the activity of superoxide dismutase (SOD) and level of adenosine triphosphate (ATP) and decreases the level of MDA in the tissue homogenate of I/R induced lung injury model. Whereas expressions of proinflammatory gene such as tumor necrosis factor α, interlukin-6, IL-1β and cycloxygenase -2 (COX-2) was found to be reduced in corilagin treated group than I/R group. Posphorylation of JNK and apoptotic rate was also found to be decreased in corilagin treated group than I/R group. Present report concludes that treatment with corilagin attenuates the lung injury in ex vivo I/R induced lung injury rat model by decreasing oxidative stress, pro-inflammatory mediators and its anti apoptotic activity.

Butyrate protects against disruption of the blood-milk barrier and moderates inflammatory responses in a model of mastitis induced by lipopolysaccharide

BACKGROUND AND PURPOSE

Short-chain fatty acids are fermentation end products produced by gut bacteria, which have been shown to ameliorate inflammatory bowel diseases and allergic asthma. However, the mechanism involved remains largely unknown. Here, we investigate the protective effects and mechanisms of sodium butyrate (SB) on LPS-induced mastitis model.

EXPERIMENTAL APPROACH

Effects of increasing doses of SB on blood-milk barrier function and inflammation are studied in BALB/c mice with LPS-induced mastitis. The underlying mechanisms of anti-inflammatory effects of SB were further investigated in LPS-stimulated mouse mammary epithelial cells (mMECs).

KEY RESULTS

The results show that SB decreased LPS-induced disruption in mammary tissues, infiltration of inflammatory cells and the levels of TNF-α, IL-6 and IL-1β. SB up-regulated the tight junction proteins occludin and claudin-3 and reduced blood-milk barrier permeability in LPS-induced mastitis. Studies in vitro revealed that SB inhibited LPS-induced inflammatory response by inhibition of the NF-κB signalling pathway and histone deacetylases in LPS-stimulated mMECs.

CONCLUSIONS AND IMPLICATIONS

In our model, SB protected against LPS-induced mastitis by preserving blood-milk barrier function and depressing pro-inflammatory responses, suggesting the potential use of SB as a prophylactic agent to protect blood-milk barrier function in mastitis.

Corticosteroids in ARDS: The Never-Ending Story

This feature examines the impact of pharmacologic interventions on the treatment of the critically ill patient — an area of health care that has become increasingly complex. Recent advances in drug therapy (including evolving and controversial data) for adult intensive-care-unit patients will be reviewed and assessed in terms of clinical, humanistic, and economic outcomes.

[Establishment of a modified rabbit model of acute lung injury induced by cardiopulmonary bypass]

OBJECTIVE

To establish an modified rabbit model of the acute lung injury induced by cardiopulmonary bypass (CPB) with ascending aorta and right atrium catheterization and detect the changes in serum tumor necrosis factor-α (TNF-α) level after modeling.

METHODS

Ten healthy adult male New Zealand rabbits were randomly selected to establish CPB models. The model establishment was deemed successful if the rabbits survived for over 4 h with stable heart beat after termination of CPB. The vital signs of the rabbits were recorded after anesthesia (T₁), before CPB (T₂), at 15 after blocking the ascending aorta and pulmonary artery (T₃), immediately after re-opening of the ascending aorta and pulmonary artery (T₄), and at 1 (T₅) and 4 (T₆) after CPB. Arterial blood gas (ABG) was monitored at T₂, T₄ and T₆ and the serum levels of TNF-α were also detected with ELISA.

RESULTS

Nine rabbit models of CPB with acute lung injury were successfully established. During the operation, the MAP was maintained at a level above 55 mmHg, HCT significantly decreased from (30.18∓2.88)% at T₂ to (17.73∓1.95)% at T₄ (P<0.05), and plasma lactate level increased significantly from 3.65∓1.13 mmol/L at T₂ to 9.36∓1.28 mmol/L at T₄ (P<0.05). The oxygenation index (PaO₂/FiO₂) at T₆ was significantly lower than that at T₂ (281.64∓55.76 vs 468.36∓56.28 mmHg, P<0.05). The serum levels of TNF-α were significantly increased (P<0.05) and obvious lung interstitial edema and inflammatory cell infiltration occurred after CPB establishment.

CONCLUSION

The modified rabbit model of CPB with acute lung injury is stable and reliable and can be used for studying acute lung injury induced by CPB.

Role of carbonyl sulfide in acute lung injury following limb ischemia/reperfusion in rats

OBJECTIVE

To investigate the effect of carbonyl sulfide (COS) on limb ischemia/reperfusion (I/R)-induced acute lung injury (ALI) and the associated mechanism in rats.

METHODS

ALI was induced by bilateral hind limb I/R in Sprague-Dawley (SD) rats. Sixty-four SD rats were randomly divided into the control group, I/R group, I/R + COS group, and I/R + AIR group. We observed the survival rate of the rats and the morphological changes of lung tissues, and we measured the change in the lung coefficient, the expression levels of the intercellular adhesion factor-1 (ICAM-1) protein in lung tissue, the expression of tumor necrosis factor (TNF)-α, interleukin (IL)-lβ, and interleukin (IL)-6 in both lung tissue and serum, and cell apoptosis.

RESULTS

Limb I/R caused significant lung tissue damage. The number of polymorphonuclear neutrophil in alveolar septa, the expression level of the ICAM-1 protein in lung tissue, the expression levels of TNF-α, IL-1, and IL-6 in lung tissue and serum, the lung coefficient, and cell apoptosis all increased. When a low dose of COS gas was administered prior to limb I/R, the variation of the above indicators was significantly reduced, while an increase in the dose of COS did not reduce the lung injury but rather increased the mortality rate.

CONCLUSION

Carbonyl sulfide is another new gaseous signaling molecule, and a low dose of exogenous COS may play a protective role in I/R-induced ALI by acting as an anti-inflammatory agent by promoting the production of antioxidants and by inhibiting the expression of adhesion molecule proteins.

Late-onset moderate to severe acute respiratory distress syndrome is associated with shorter survival and higher mortality: a two-stage association study

PURPOSE

To evaluate the association between acute respiratory distress syndrome (ARDS) onset time and prognosis.

METHODS

Patients with moderate to severe ARDS (N = 876) were randomly assigned into derivation (N = 520) and validation (N = 356) datasets. Both 28-day and 60-day survival times after ARDS onset were analyzed. A data-driven cutoff point between early- and late-onset ARDS was determined on the basis of mortality risk effects of onset times. We estimated the hazard ratio (HR) and odds ratio (OR) of late-onset ARDS using a multivariate Cox proportional hazards model of survival time and a multivariate logistic regression model of mortality rate, respectively.

RESULTS

Late-onset ARDS, defined as onset over 48 h after intensive care unit (ICU) admission (N = 273, 31%), was associated with shorter 28-day survival time: HR = 2.24, 95% CI 1.48-3.39, P = 1.24 × 10^-4 (derivation); HR = 2.16, 95% CI 1.33-3.51, P = 1.95 × 10^-3 (validation); and HR = 2.00, 95% CI 1.47-2.72, P = 1.10 × 10^-5 (combined dataset). Late-onset ARDS was also associated with shorter 60-day survival time: HR = 1.70, 95% CI 1.16-2.48, P = 6.62 × 10^-3 (derivation); HR = 1.78, 95% CI 1.15-2.75, P = 9.80 × 10^-3 (validation); and HR = 1.59, 95% CI 1.20-2.10, P = 1.22 × 10^-3 (combined dataset). Meanwhile, late-onset ARDS was associated with higher 28-day mortality rate (OR = 1.46, 95% CI 1.04-2.06, P = 0.0305) and 60-day mortality rate (OR = 1.44, 95% CI 1.03-2.02, P = 0.0313).

CONCLUSIONS

Late-onset moderate to severe ARDS patients had both shorter survival time and higher mortality rate in 28-day and 60-day observations.

Endocan and the respiratory system: a review

Endocan, formerly called endothelial cell-specific molecule 1, is an endothelial cell-associated proteoglycan that is preferentially expressed by renal and pulmonary endothelium. It is upregulated by proangiogenic molecules as well as by pro-inflammatory cytokines, and since it reflects endothelial activation and dysfunction, it is regarded as a novel tissue and blood-based relevant biomarker. As such, it is increasingly being researched and evaluated in a wide spectrum of healthy and disease pathophysiological processes. Here, we review the present scientific knowledge on endocan, with emphasis on the evidence that underlines its possible clinical value as a prognostic marker in several malignant, inflammatory and obstructive disorders of the respiratory system.

The PI3K/Akt, p38MAPK, and JAK2/STAT3 signaling pathways mediate the protection of SO2 against acute lung injury induced by limb ischemia/reperfusion in rats

Sulfur dioxide (SO2) is naturally synthesized by glutamate-oxaloacetate transaminase (GOT) from L-cysteine in mammalian cells. We found that SO2 may have a protective effect on acute lung injury (ALI) induced by limb ischemia/reperfusion (I/R) in rats. The PI3K/Akt, p38MAPK, and JAK2/STAT3 pathways are crucial in cell signaling transduction. The present study aims to verify the role of SO2 on limb I/R-induced ALI, and investigate whether PI3K/Akt, p38MAPK, and JAK2/STAT3 pathways were involved, as well as the relationship among the three pathways; we used specific inhibitors (LY294002, SB03580, and Stattic) to block them, respectively. The experimental methods of Western, ELISA, TUNEL, etc., were used to test the results. In the I/R group, the parameters of lung injury (MDA, MPO, TUNEL, cytokines) increased significantly, but the administration of Na2SO3/NaHSO3 attenuated the damage in the lung. The Western results showed that the rat's lung exist expression of P-STAT3, P-AKT, and P-p38 proteins. After I/R, P-STAT3, P-Akt, and P-p38 proteins expression all increased. After using Na2SO3/NaHSO3, P-Akt, and P-p38 proteins expression increased, but P-STAT3 protein expression decreased. We also found a strange phenomenon; compared to the I/R + SO2 group, the administration of stattic, P-p38 protein expression showed no change, but P-Akt protein expression increased (p < 0.05). In conclusion, SO2 has a protective effect on rats with limb I/R-induced ALI. The JAK2/STAT3, PI3K/Akt, and p38MAPK pathways are likely all involved in the process, and the JAK2/STAT3 pathway may have an impact on the P13K/Akt pathway.

Structural analogs of pulmonary surfactant phosphatidylglycerol inhibit toll-like receptor 2 and 4 signaling

The pulmonary surfactant phospholipid, 1-palmitoyl-2-oleoylphosphatidylglycerol (POPG), potently inhibits toll-like receptor (TLR)2 and TLR4 signaling from the cell surface of macrophages. Analogs of POPG that vary in polar head group length, hydroxylation, and alkyl branching were synthesized using a phospholipase D-catalyzed transphosphatidylation reaction and a 1-palmitoyl-2-oleoyl phosphatidylcholine substrate. Lipid analogs with C3 and C4 alkyl head group length (POP-propanol and POP-butanol) are less effective than POPG as TLR2 and TLR4 antagonists. However, adding a hydroxyl group at the alkyl chain 3- or 4-position (POP-propanediols or POP-butanediols) greatly increased their inhibitory effects against TLR2 and TLR4. POP-2',2'-dimethylpropanediol is a weak inhibitor of TLR2 and TLR4 activation that results in arachidonic acid release, but an effective inhibitor of TLR4 activation that results in TNF-α production. Addition of an amino group at the alkyl-2 position (POP-2'-aminopropanediol) completely abolished the antagonism of TLRs 2 and 4. Multiple analogs strongly bind to the TLR4 coreceptors, cluster of differentiation 14 (CD14) and myeloid differentiation 2, but competition for di[3-deoxy-D-manno-octulosonyl]-lipid A binding to CD14 is the best predictor of biological activity at the cellular level. Collectively, these findings identify new compounds for antagonizing TLR2 and TLR4 activation and define structural properties of POPG analogs for discriminating between two TLR systems.

Clausena anisata-mediated protection against lipopolysaccharide-induced acute lung injury in mice

Clausena anisata (Willd.) Hook.f. ex Benth. (CA), which is widely used in traditional medicine, reportedly exerts antitumor, anti-inflammatory and other important therapeutic effects. The aim of the present study was to investigate the potential therapeutic effects of CA in a mouse model of lipopolysaccharide (LPS)-induced acute lung injury (ALI) and in LPS-stimulated RAW 264.7 cells. Male C57BL/6 mice were administered treatments for 3 days by oral gavage. On day 3, the mice were instilled intranasally with LPS or PBS followed 3 h later by oral CA (30 mg/kg) or vehicle administration. In vitro, CA decreased nitric oxide (NO) production and pro-inflammatory cytokines, such as interleukin (IL)-6 and prostaglandin E2 (PGE2), in LPS-stimulated RAW 264.7 cells. CA also reduced the expression of pro-inflammatory mediators, such as cyclooxygenase-2. In vivo, CA administration significantly reduced inflammatory cell numbers in the bronchoalveolar lavage fluid (BALF) and suppressed pro-inflammatory cytokine levels, including tumor necrosis factor-α (TNF-α), IL-6, and IL-1β, as well as reactive oxygen species production in the BALF. CA also effectively reduced airway inflammation in mouse lung tissue of an LPS-induced ALI mouse model, in addition to decreasing inhibitor κB (IκB) and nuclear factor-κB (NF-κB) p65 phosphorylation. Taken together, the findings demonstrated that CA inhibited inflammatory responses in a mouse model of LPS-induced ALI and in LPS-stimulated RAW 264.7 cells. Thus, CA is a potential candidate for development as an adjunctive treatment for inflammatory disorders, such as ALI.

Selenium Deficiency Facilitates Inflammation Through the Regulation of TLR4 and TLR4-Related Signaling Pathways in the Mice Uterus

Selenium (Se) is an essential nutritional trace element that affects the development and function of the reproductive system. Endometritis is a reproductive obstacle disease that can seriously reduce the reproductive capacity of animal. To study the effects of dietary Se deficiency on lipopolysaccharide (LPS)-induced mice endometritis, we generated a model of LPS-induced mice endometritis. The Se content in uterine tissues was detected by fluorescence spectrophotometry. The levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, and IL-6 were measured by enzyme-linked immunosorbent assay (ELISA) and quantitative real-time polymerase chain reaction (qRT-PCR). The extent of phosphorylation of IκBα, NF-κB p65, ERK, JNK, and p38 and the expression of Toll-like receptor 4 (TLR4) were detected with Western blots. The TLR4 messenger RNA (mRNA) was analyzed with qRT-PCR. The results indicated that dietary Se intake significantly influenced Se levels in uterine tissues. The Se-deficient mice model was successfully replicated, and Se deficiency exacerbated uterine tissue histopathology; increased the expression of TNF-α, IL-1β, and IL-6; facilitated the activation of TLR4; and enhanced the phosphorylation of IκBα, p65, ERK, JNK, and p38 in LPS-induced mice endometritis. Also, the effects were inhibited by a supplement of Se. In conclusion, our studies demonstrated that Se deficiency makes mice uterus more prone to inflammation. An appropriate Se supplement could enhance the immune condition of the uterus.

Bergenin Plays an Anti-Inflammatory Role via the Modulation of MAPK and NF-κB Signaling Pathways in a Mouse Model of LPS-Induced Mastitis

Mastitis is a major disease in humans and other animals and is characterized by mammary gland inflammation. It is a major disease of the dairy industry. Bergenin is an active constituent of the plants of genus Bergenia. Research indicates that bergenin has multiple biological activities, including anti-inflammatory and immunomodulatory properties. The objective of this study was to evaluate the protective effects and mechanism of bergenin on the mammary glands during lipopolysaccharide (LPS)-induced mastitis. In this study, mice were treated with LPS to induce mammary gland mastitis as a model for the disease. Bergenin treatment was initiated after LPS stimulation for 24 h. The results indicated that bergenin attenuated inflammatory cell infiltration and decreased the concentration of NO, TNF-α, IL-1β, and IL-6, which were increased in LPS-induced mouse mastitis. Furthermore, bergenin downregulated the phosphorylation of nuclear factor-kappaB (NF-κB) and mitogen-activated protein kinases (MAPK) signaling pathway proteins in mammary glands with mastitis. In conclusion, bergenin reduced the expression of NO, TNF-α, IL-1β, and IL-6 proinflammatory cytokines by inhibiting the activation of the NF-κB and MAPKs signaling pathways, and it may represent a novel treatment strategy for mastitis.

Soyasaponin Ab inhibits lipopolysaccharide-induced acute lung injury in mice

Soyasaponin Ab (SA) has been reported to have anti-inflammatory effect. However, the effects of SA on lipopolysaccharide (LPS)-induced acute lung injury (ALI) have not been reported. The aim of this study was to investigate the anti-inflammatory effects of SA on LPS-induced ALI and clarify the possible mechanism. The mice were stimulated with LPS to induce ALI. SA was given 1h after LPS treatment. 12h later, lung tissues were collected to assess pathological changes and edema. Bronchoalveolar lavage fluid (BALF) was collected to assess inflammatory cytokines and nitric oxide (NO) production. In vitro, mice alveolar macrophages were used to investigate the anti-inflammatory mechanism of SA. Our results showed that SA attenuated LPS-induced lung pathological changes, edema, the expression of cycloxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) in lung tissues, as well as TNF-α, IL-6, IL-1β, and NO production in mice. Meanwhile, SA up-regulated the activities of superoxide dismutase (SOD) and catalase decreased by LPS in mice. SA also inhibited LPS-induced TNF-α, IL-6 and IL-1β production as well as NF-κB activation in alveolar macrophages. Furthermore, SA could activate Liver X Receptor Alpha (LXRα) and knockdown of LXRα by RNAi abrogated the anti-inflammatory effects of SA. In conclusion, the current study demonstrated that SA exhibited protective effects against LPS-induced acute lung injury and the possible mechanism was involved in activating LXRα, thereby inhibiting LPS-induced inflammatory response.

Anti-inflammatory and anti-apoptotic effects of oxysophoridine on lipopolysaccharide-induced acute lung injury in mice

Oxysophoridine (OSR) is an alkaloid with multiple pharmacological activities. This study aimed to investigate the protective effects and underlying mechanisms of OSR on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice. Here, we found that OSR treatment markedly mitigated LPS-induced body weight loss and significant lung injury characterized by the deterioration of histopathology, histologic scores, wet-to-dry ratio, exduate volume, and protein leakage. OSR dramatically attenuated LPS-induced lung inflammation, as evidenced by the reduced levels of total cells, neutrophils, lymphocytes, and macrophages and pro-inflammatory cytokines (i.e., tumor necrosis factor-α, interleukin (IL)-1β, IL-6, and monocyte chemoattractant protein-1) in bronchoalveolar lavage fluid and of their mRNA expression in lung tissues. OSR also inhibited LPS-induced expression and activation of nuclear factor-κB p65 in pulmonary tissue. Additionally, OSR administration markedly prevented LPS-induced pulmonary cell apoptosis in mice, as reflected by the decrease in expression of procaspase-8, procaspase-3, cleaved caspase-8, and cleaved caspase-3, and Bcl-2-associated X/B-cell lymphoma 2 ratio. These results indicate that OSR is a potential therapeutic drug for treating LPS-induced ALI.

Protective effects of patchouli alcohol isolated from Pogostemon cablin on lipopolysaccharide-induced acute lung injury in mice

Patchouli alcohol (PA) is a tricyclic sesquiterpene isolated from Pogostemon cablin, which exerts anti-inflammatory, anti-influenza and cognitive-enhancing bioactivities. The present study aimed to investigate the protective effects of PA on acute lung injury (ALI) induced by intratracheal instillation of lipopolysaccharide (LPS) in mice. Dexamethasone was used as a positive drug for protection against LPS-induced ALI. The results of the present study demonstrated that pretreatment with PA significantly increased survival rate, attenuated histopathologic damage and lung edema, and decreased the protein content in the bronchoalveolar lavage fluid (BALF) of mice with ALI. Furthermore, PA significantly inhibited the expression levels of proinflammatory cytokines, including tumor necrosis factor (TNF)-α and interleukin (IL)-6 in the BALF, downregulated the levels of myeloperoxidase and malondialdehyde, and upregulated the activity levels of superoxide dismutase and glutathione peroxidase in lung tissue. These results indicated that PA may exert potent protective effects against LPS-induced ALI in mice, the mechanisms of which are possibly associated with the anti-inflammatory and antioxidative activities of PA.

Postperfusion lung syndrome: Respiratory mechanics, respiratory indices and biomarkers

Postperfusion lung syndrome is rare but lethal. Secondary inflammatory response was the popularly accepted theory for the underlying etiology. Respiratory index (RI) and arterial oxygen tension/fractional inspired oxygen can be reliable indices for the diagnosis of this syndrome as X-ray appearance is always insignificant at the early stage of the onset. Evaluations of extravascular lung water content and pulmonary compliance are also helpful in the definite diagnosis. Multiorgan failure and triple acid-base disturbances that might develop secondary to postperfusion lung syndrome are responsible for the poor prognosis and increased mortality rather than postperfusion lung syndrome itself. Mechanical ventilation with low tidal volume (TV) and proper positive end-expiratory pressure can be an effective treatment strategy. Use of ulinastatin and propofol may benefit the patients through different mechanisms.

Postperfusion lung syndrome: physiopathology and therapeutic options

Postperfusion lung syndrome is rare but can be lethal. The underlying mechanism remains uncertain but triggering inflammatory cascades have become an accepted etiology. A better understanding of the pathophysiology and the roles of inflammatory mediators in the development of the syndrome is imperative in the determination of therapeutic options and promotion of patients' prognosis and survival. Postperfusion lung syndrome is similar to adult respiratory distress syndrome in clinical features, diagnostic approaches and management strategies. However, the etiologies and predisposing risk factors may differ between each other. The prognosis of the postperfusion lung syndrome can be poorer in comparison to acute respiratory distress syndrome due to the secondary multiple organ failure and triple acid-base imbalance. Current management strategies are focusing on attenuating inflammatory responses and preventing from pulmonary ischemia-reperfusion injury. Choices of cardiopulmonary bypass circuit and apparatus, innovative cardiopulmonary bypass techniques, modified surgical maneuvers and several pharmaceutical agents can be potential preventive strategies for acute lung injury during cardiopulmonary bypass.

Asiaticoside attenuates lipopolysaccharide-induced acute lung injury via down-regulation of NF-κB signaling pathway

Asiaticoside (AS), a triterpene glycoside isolated from Centella asiatica, has been shown to possess potent anti-inflammatory activity. However, the detailed molecular mechanisms of AS on lipopolysaccharide (LPS)-induced acute lung injury (ALI) model in mice are scanty. The purpose of this study was to evaluate the effect of AS on LPS-induced mouse ALI via down-regulation of NF-κB signaling pathway. We investigated the efficacy of AS on cytokine levels induced by LPS in bronchoalveolar lavage fluid (BALF) and RAW 264.7 cells. The production of cytokine (TNF-α and IL-6) was measured by enzyme-linked immunosorbent assay (ELISA). The lung wet-to-dry weight ratios were measured in LPS-challenged mice, and lung histopathologic changes observed via paraffin section were assessed. To further study the mechanism of AS protective effects on ALI, the activation of NF-κB p65 subunit and the degradation of IκBα were tested by western blot assay. We found that AS treatment at 15, 30 or 45mg/kg dose-dependently attenuated LPS-induced pulmonary inflammation by reducing inflammatory infiltration, histopathological changes, descended cytokine production, and pulmonary edema initiated by LPS. Furthermore, our results suggested that AS suppressed inflammatory responses in LPS-induced ALI through inhibition of the phosphorylation of NF-κB p65 subunit and the degradation of its inhibitor IκBα, and might be a new preventive agent of ALI in the clinical setting.

A Standardized Traditional Chinese Medicine Preparation Named Yejuhua Capsule Ameliorates Lipopolysaccharide-Induced Acute Lung Injury in Mice via Downregulating Toll-Like Receptor 4/Nuclear Factor-κB

A standardized traditional Chinese medicine preparation named Yejuhua capsule (YJH) has been clinically used in treatments of various acute respiratory system diseases with high efficacy and low toxicity. In this study, we were aiming to evaluate potential effects and to elucidate underlying mechanisms of YJH against lipopolysaccharide- (LPS-) induced acute lung injury (ALI) in mice. Moreover, the chemical analysis and chromatographic fingerprint study were performed for quality evaluation and control of this drug. ALI was induced by intratracheal instillation of LPS (5 mg/kg) into the lung in mice and dexamethasone (5 mg/kg, p.o.) was used as a positive control drug. Results demonstrated that pretreatments with YJH (85, 170, and 340 mg/kg, p.o.) effectively abated LPS-induced histopathologic changes, attenuated the vascular permeability enhancement and edema, inhibited inflammatory cells migrations and protein leakages, suppressed the ability of myeloperoxidase, declined proinflammatory cytokines productions, and downregulated activations of nuclear factor-κB (NF-κB) and expressions of toll-like receptor 4 (TLR4). This study demonstrated that YJH exerted potential protective effects against LPS-induced ALI in mice and supported that YJH was a potential therapeutic drug for ALI in clinic. And its mechanisms were at least partially associated with downregulations of TLR4/NF-κB pathways.

Anti-inflammatory effects of triptolide in LPS-induced acute lung injury in mice

Triptolide is one of the main active components of Chinese herb Tripterygium wilfordii Hook F, which has been demonstrated to have anti-inflammatory properties. The aim of this study was to investigate the effects of triptolide on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice and to clarify the possible mechanisms. Mice were administered intranasally with LPS to induce lung injury. Triptolide was administered intraperitoneally 1 h before LPS challenge. Triptolide-treated mice exhibited significantly reduced leukocyte, myeloperoxidase (MPO) activity, edema of the lung, as well as TNF-α, IL-1β, and IL-6 production in the bronchoalveolar lavage fluid compared with LPS-treated mice. Additionally, Western blot analysis showed that triptolide inhibited the phosphorylation of inhibitor-kappa B kinase-alpha (IκB-α), p65, nuclear factor kappa B (NF-κB), p38, extracellular receptor kinase (ERK), and Jun N-terminal kinase (JNK) and the expression of Toll-like receptor 4 (TLR4) caused by LPS. In conclusion, our results suggested that the promising anti-inflammatory mechanism of triptolide may be that triptolide activates peroxisome proliferation-activated receptor gamma (PPAR-γ), thereby attenuating an LPS-induced inflammatory response. Triptolide may be a promising potential therapeutic reagent for ALI treatment.

Lotus leaf (Nelumbo nucifera) and its active constituents prevent inflammatory responses in macrophages via JNK/NF-κB signaling pathway

Inflammation is a serious health issue worldwide that induces many diseases, such as inflammatory bowel disease (IBD), sepsis, acute pancreatitis and lung injury. Thus, there is a great deal of interest in new methods of limiting inflammation. In this study, we investigated the leaves of Nelumbo nucifera Gaertn, an aquatic perennial plant cultivated in eastern Asia and India, in anti-inflammatory pharmacological effects in the murine macrophage cell line RAW264.7. Results showed that lipopolysaccharide (LPS) increased the protein expression of inducible nitric oxide synthase (iNOS) and COX-2, as well as the mRNA expression and level of IL-6 and TNF-α, while NNE significantly reduced these effects of LPS. LPS also induced phospho-JNK protein expression. The JNK-specific inhibitor SP600125 decreased the proteins expression of phospho-JNK, iNOS, COX-2, and the mRNAs expression and levels of IL-6 and TNF-α. Further, NNE reduced the protein expression of phospho-JNK. LPS was also found to promote the translocation of NF-κB from the cytosol to the nucleus and to decrease the expression of cytosolic IκB. NNE and SP600125 treatment recovered the LPS-induced expression of NF-κB and IκB. While phospho-ERK and phospho-p38 induced by LPS, could not be reversed by NNE. To further investigate the major components of NNE in anti-inflammatory effects, we determined the quercetin and catechin in inflammatory signals. Results showed that quercetin and catechin significantly decreased the proteins expression of iNOS, COX-2 and phospho-JNK. Besides, the mRNAs and levels of IL-6 and TNF-α also decreased by quercetin and catechin treatment in LPS-induced RAW264.7 cells. These results showed that NNE and its major components quercetin and catechin exhibit anti-inflammatory activities by inhibiting the JNK- and NF-κB-regulated pathways and could therefore be an useful anti-inflammatory agent.

Soluble factors from Lactobacillus reuteri CRL1098 have anti-inflammatory effects in acute lung injury induced by lipopolysaccharide in mice

We have previously demonstrated that Lactobacillus reuteri CRL1098 soluble factors were able to reduce TNF-α production by human peripheral blood mononuclear cells. The aims of this study were to determine whether L. reuteri CRL1098 soluble factors were able to modulate in vitro the inflammatory response triggered by LPS in murine macrophages, to gain insight into the molecular mechanisms involved in the immunoregulatory effect, and to evaluate in vivo its capacity to exert anti-inflammatory actions in acute lung injury induced by LPS in mice. In vitro assays demonstrated that L. reuteri CRL1098 soluble factors significantly reduced the production of pro-inflammatory mediators (NO, COX-2, and Hsp70) and pro-inflammatory cytokines (TNF-α, and IL-6) caused by the stimulation of macrophages with LPS. NF-kB and PI3K inhibition by L. reuteri CRL1098 soluble factors contributed to these inhibitory effects. Inhibition of PI3K/Akt pathway and the diminished expression of CD14 could be involved in the immunoregulatory effect. In addition, our in vivo data proved that the LPS-induced secretion of the pro-inflammatory cytokines, inflammatory cells recruitment to the airways and inflammatory lung tissue damage were reduced in L. reuteri CRL1098 soluble factors treated mice, providing a new way to reduce excessive pulmonary inflammation.

Cepharanthine, an alkaloid from Stephania cepharantha Hayata, inhibits the inflammatory response in the RAW264.7 cell and mouse models

The aim of this study was to investigate the protective effects of cepharanthine (CEP) on inflammation in lipopolysaccharide (LPS)-stimulated RAW264.7 cells in vitro and a LPS-induced lung injury model in vivo. RAW264.7 cells were treated with various concentrations of CEP for 1 h followed by incubation with or without 1 μg/ml LPS for 18 h. TNF-α, IL-6, and IL-1β in the supernatants were measured by ELISA. Nuclear factor-κB (NF-κB) and mitogen-activated protein kinase pathways were analyzed by Western blot. Mice were randomly divided into control group, LPS group, CEP + LPS group, and dexamethasone + LPS group. A male BALB/c mouse model of acute lung injury was induced by LPS. Bronchoalveolar lavage fluid was collected for inflammatory cell count and cytokine assays. Histopathologic examination was performed on mice that were not subjected to bronchoalveolar lavage fluid collection. CEP dose-dependently inhibited the release of TNF-α, IL-6, and IL-1β in LPS-stimulated RAW264.7 cells. Significantly, CEP dose-dependently suppressed NF-κB activation, IκBα degradation, and phosphorylation of ERK, JNK, and p38 induced by LPS. In vivo, it was also observed that CEP attenuated lung histopathologic changes and down-regulated the level of pro-inflammatory cytokines, including TNF-α, IL-1β, and IL-6, in the mouse acute lung injury model. These results suggest that CEP potentially decreases inflammation in vitro and in vivo and might be a therapeutic agent against inflammatory diseases.

Gene expression profiles analysis identifies key genes for acute lung injury in patients with sepsis

BACKGROUND

To identify critical genes and biological pathways in acute lung injury (ALI), a comparative analysis of gene expression profiles of patients with ALI + sepsis compared with patients with sepsis alone were performed with bioinformatic tools.

METHODS

GSE10474 was downloaded from Gene Expression Omnibus, including a collective of 13 whole blood samples with ALI + sepsis and 21 whole blood samples with sepsis alone. After pre-treatment with robust multichip averaging (RMA) method, differential analysis was conducted using simpleaffy package based upon t-test and fold change. Hierarchical clustering was also performed using function hclust from package stats. Beisides, functional enrichment analysis was conducted using iGepros. Moreover, the gene regulatory network was constructed with information from Kyoto Encyclopedia of Genes and Genomes (KEGG) and then visualized by Cytoscape.

RESULTS

A total of 128 differentially expressed genes (DEGs) were identified, including 47 up- and 81 down-regulated genes. The significantly enriched functions included negative regulation of cell proliferation, regulation of response to stimulus and cellular component morphogenesis. A total of 27 DEGs were significantly enriched in 16 KEGG pathways, such as protein digestion and absorption, fatty acid metabolism, amoebiasis, etc. Furthermore, the regulatory network of these 27 DEGs was constructed, which involved several key genes, including protein tyrosine kinase 2 (PTK2), v-src avian sarcoma (SRC) and Caveolin 2 (CAV2).

CONCLUSION

PTK2, SRC and CAV2 may be potential markers for diagnosis and treatment of ALI.

VIRTUAL SLIDES

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/5865162912987143.