Emerging therapies for the prevention of acute respiratory distress syndrome

Preclinical evidence of the anti-inflammatory effect and toxicological safety of aryl-cyclohexanone in vivo

BACKGROUND

Respiratory distress syndrome is a complex inflammatory condition defined by the presence of acute hypoxemia and cellular infiltration with diffuse alveolar injury following a tissue injury, such as acute lung injury. The inflammatory process involved in this pathology is a defense mechanism of the body against infectious agents and/or tissue injuries. However, when the condition is not reversed, it becomes a significant cause of tissue damage, sometimes leading to loss of function of the affected organ. Therefore, it is essential to understand the mechanisms underlying inflammation, as well as the development of new therapeutic agents that reduce inflammatory damage in these cases. Aryl-cyclohexanone derivatives have previously shown significant anti-inflammatory activity linked to an immunomodulatory capacity in vitro and may be good candidates for therapies in which inflammation plays a central role.

METHODS

Was evaluated the anti-inflammatory capacity of a synthesized molecule aryl-cyclohexanone in the murine model of lipopolysaccharide (LPS)-induced acute lung injury. The assessment of acute oral toxicity follows the Organization for Economic Co-operation and Development (OECD) guideline 423.

RESULTS

The results demonstrated that the studied molecule protects against LPS-induced inflammation. We observed a decrease in the migration of total and differential leukocytes to the bronchoalveolar lavage fluid (BALF), in addition to a reduction in exudation, myeloperoxidase (MPO) activity, nitric oxide metabolites, and the secretion of pro-inflammatory cytokines (alpha tumor necrosis factors [TNF-α], interleukin-6 [IL-6], interferon-gamma [IFN-γ], and monocyte chemoattractant protein-1 [MCP-1]). Finally, aryl cyclohexanone did not show signs of acute oral toxicity (OECD 423).

CONCLUSIONS

The results prove our hypothesis that aryl-cyclohexanone is a promising molecule for developing a new, safe anti-inflammatory drug.

The Alleviation of LPS-Induced Murine Acute Lung Injury by GSH-Mediated PEGylated Artesunate Prodrugs

Acute lung injury (ALI) or its aggravated stage acute respiratory distress syndrome (ARDS) is a common severe clinical syndrome in intensive care unit, may lead to a life-threatening form of respiratory failure, resulting in high mortality up to 30–40% in most studies. Nanotechnology-mediated anti-inflammatory therapy is an emerging novel strategy for the treatment of ALI, has been demonstrated with unique advantages in solving the dilemma of ALI drug therapy. Artesunate (ART), a derivative of artemisinin, has been reported to have anti-inflammatory effects. Therefore, in the present study, we designed and synthesized PEGylated ART prodrugs and assessed whether ART prodrugs could attenuate lipopolysaccharide (LPS) induced ALI in vitro and in vivo. All treatment groups were conditioned with ART prodrugs 1 h before challenge with LPS. Significant increased inflammatory cytokines production and decreased GSH levels were observed in the LPS stimulated mouse macrophage cell line RAW264.7. Lung histopathological changes, lung W/D ratio, MPO activity and total neutrophil counts were increased in the LPS-induced murine model of ALI via nasal administration. However, these results can be reversed to some extent by treatment of ART prodrugs. The effectiveness of mPEG_2k-SS-ART in inhibition of ALI induced by LPS was confirmed. In conclusion, our results demonstrated that the ART prodrugs could attenuate LPS-induced ALI effectively, and mPEG_2k-SS-ART may serve as a novel strategy for treatment of inflammation induced lung injury.

A digital health platform for assisting the diagnosis and monitoring of COVID-19 progression: An adjuvant approach for augmenting the antiviral response and mitigating the immune-mediated target organ damage

Coronavirus disease 2019 (COVID-19), which is a respiratory illness associated with high mortality, has been classified as a pandemic. The major obstacles for the clinicians to contain the disease are limited information availability, difficulty in disease diagnosis, predicting disease prognosis, and lack of disease monitoring tools. Additionally, the lack of valid therapies has further contributed to the difficulties in containing the pandemic. Recent studies have reported that the dysregulation of the immune system leads to an ineffective antiviral response and promotes pathological immune response, which manifests as ARDS, myocarditis, and hepatitis. In this study, a novel platform has been described for disseminating information to physicians for the diagnosis and monitoring of patients with COVID-19. An adjuvant approach using compounds that can potentiate antiviral immune response and mitigate COVID-19-induced immune-mediated target organ damage has been presented. A prolonged beneficial effect is achieved by implementing algorithm-based individualized variability measures in the treatment regimen.

Donor factors and risk of primary graft dysfunction and mortality post lung transplantation: A proposed conceptual framework

Lung transplantation remains a therapeutic option in end-stage lung disease. However, despite advances in the field, early allograft function can be compromised by the development of primary graft dysfunction (PGD); this being the leading cause of morbidity and mortality immediately following the lung transplant procedure. Several recipient factors have been associated with increased risk of PGD, but less is known about donor factors. Aging, tobacco, and chronic alcohol use are donor factors implicated, but how these factors promote PGD remains unclear. Herein, we discuss the available clinical data that link these donor factors with outcomes after lung transplantation, and how they might render the recipient susceptible to PGD through a two-hit process.

Mechanism of Anti-Inflammatory Activity of TLR4-Interacting SPA4 Peptide

The TLR4-interacting SPA4 peptide suppresses inflammation. We assessed the structural and physicochemical properties and binding of SPA4 peptide to TLR4-MD2. We also studied the changes at the whole transcriptome level, cell morphology, viability, secreted cytokines and chemokines, and cell influx in cell systems and mouse models challenged with LPS and treated with SPA4 peptide. Our results demonstrated that the SPA4 peptide did not alter the cell viability and size and only moderately affected the transcriptome of the cells. Computational docking and rendering suggested that the SPA4 peptide intercalates with LPS-induced TLR4-MD2 complex. Results with alanine mutations of D-2 amino acid and NYTXXXRG-12-19 motif of SPA4 peptide suggested their role in binding to TLR4 and in reducing the cytokine response against LPS stimulus. Furthermore, therapeutically administered SPA4 peptide significantly suppressed the secreted levels of cytokines and chemokines in cells and bronchoalveolar lavage fluids of LPS-challenged mice. The results suggest that the SPA4 peptide intercalates with LPS-induced TLR4 complex and signaling for the suppression of inflammation.

Detection of hypochlorous acid fluctuation via a selective fluorescent probe in acute lung injury cells and mouse models

Acute lung injury (ALI) is a diffuse inflammatory pulmonary damage caused by excessive ROS that break the coordination of normal physiological structures and functions. Hypochlorous acid (HOCl), one kind of ROS, is a hopeful biological marker for inflammation-related diseases. Therefore, the excessive generation of HOCl might be a significant reason for oxidative injury in ALI. Herein, we developed a fluorescent probe, namely BCy-HOCl, for quantitatively monitoring and visualizing HOCl in living cells and in vivo. The probe BCy-HOCl displayed a significant fluorescence signal enhancement towards HOCl with excellent selectivity and sensitivity. The variation of HOCl in the ALI cell model and ALI mouse model was evaluated with BCy-HOCl to clarify the relationship between ALI and HOCl. Our results verified that the HOCl levels conspicuously increased with the severity of the ALI. Thus, HOCl is likely to play a crucial part in the process of ALI, which will probably provide a new strategy for its treatment.

Comprehensive Analysis of LncRNA-mRNA Expression Profiles and the ceRNA Network Associated with Pyroptosis in LPS-Induced Acute Lung Injury

Purpose

To explore the molecular mechanism and search for candidate lncRNA and mRNA associated with pyroptosis in the gene expression profile of LPS-induced acute lung injury (ALI).

Methods

We investigated lncRNA and mRNA expression in lipopolysaccharide (LPS)-induced ALI at an early stage. RNA sequencing (RNA-Seq) was carried out to analyze lncRNA and mRNA expression profiles between the LPS-induced and control groups. We used bioinformatics analysis to predict target genes of early differential lncRNAs among obtained the differential mRNAs.

Results

A total of 78 lncRNAs and 248 mRNAs were upregulated at 2 hours and downregulated at 9 hours, and 21 lncRNAs and 107 mRNAs were downregulated at 2 and upregulated at 9 hours in early ALI models. We predicted 7 cis-and trans-regulated target genes of the top 20 lncRNAs. Gene Ontology (GO) analysis indicated that the target genes for the screened lncRNAs were most enriched in three-terms: regulation of protein serine/threonine kinase activity, pertussis, and cellular response to LPS. Additionally, target genes of lncRNAs were the top three enriched in pertussis, osteoclast differentiation, and cAMP signaling pathways with Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. We also identified vital mRNAs and lncRNAs. Protein-protein interaction (PPI) network analysis suggested that Tnf, Jun, and Atf3 were the top three key genes. Hub lncRNA4344 (NONRATT004344.2) and cis-regulated target mRNA (NLRP3) were validated in vitro. Finally, luciferase assay results confirmed that lncRNA4344 sponged miR‐138-5p to promote pyroptosis in inflammatory responses to LPS‐induced acute lung injury by targeting NLRP3.

Conclusion

Based on analysis of lncRNA and mRNA expression profiles by RNA-Seq and experimental verification, this study is the first to reveal that lncRNA4344 sponged miR‐138-5p to promote pyroptosis in inflammatory responses of LPS‐induced acute lung injury by targeting NLRP3. These newly identified lncRNA, miRNA, and mRNA might be novel potential targets for early treatment and prevention in early ALI.

Are losartan and imatinib effective against SARS-CoV2 pathogenesis? A pathophysiologic-based in silico study

Proposing a theory about the pathophysiology of cytokine storm in COVID19, we were to find the potential drugs to treat this disease and to find any effect of these drugs on the virus infectivity through an in silico study. COVID-19-induced ARDS is linked to a cytokine storm phenomenon not explainable solely by the virus infectivity. Knowing that ACE2, the hydrolyzing enzyme of AngII and SARS-CoV2 receptor, downregulates when the virus enters the host cells, we hypothesize that hyperacute AngII upregulation is the eliciting factor of this ARDS. We were to validate this theory through reviewing previous studies to figure out the role of overzealous activation of AT1R in ARDS. According to this theory losartan may attenuate ARDS in this disease. Imatinib, has previously been elucidated to be promising in modulating lung inflammatory reactions and virus infectivity in SARS and MERS. We did an in silico study to uncover any probable other unconsidered inhibitory effects of losartan and imatinib against SARS-CoV2 pathogenesis. Reviewing the literature, we could find that over-activation of AT1R could explain precisely the mechanism of cytokine storm in COVID19. Our in silico study revealed that losartan and imatinib could probably: (1) decline SARS-CoV2 affinity to ACE2. (2) inhibit the main protease and furin, (3) disturb papain-like protease and p38MAPK functions. Our reviewing on renin-angiotensin system showed that overzealous activation of AT1R by hyper-acute excess of AngII due to acute downregulation of ACE2 by SARS-CoV2 explains precisely the mechanism of cytokine storm in COVID-19. Besides, based on our in silico study we concluded that losartan and imatinib are promising in COVID19.

Basic Critical Care for Management of COVID-19 Patients: Position Paper of Indian Society of Critical Care Medicine, Part-I

With more than 23 million infections and more than 814,000 deaths worldwide, the coronavirus disease-2019 (COVID-19) pandemic is still far from over. Several classes of drugs including antivirals, antiretrovirals, anti-inflammatory, immunomodulatory, and antibiotics have been tried with varying levels of success. Still, there is lack of any specific therapy to deal with this infection. Although less than 30% of these patients require intensive care unit admission, morbidity and mortality in this subgroup of patients remain high. Hence, it becomes imperative to have general principles to guide intensivists managing these patients. However, as the literature emerges, these recommendations may change and hence, frequent updates may be required. How to cite this article: Juneja D, Savio RD, Srinivasan S, Pandit RA, Ramasubban S, Reddy PK, et al. Basic Critical Care for Management of COVID-19 Patients: Position Paper of Indian Society of Critical Care Medicine, Part-I. Indian J Crit Care Med 2020;24(Suppl 5):S244-S253.

Combination of C21 and ARBs with rhACE2 as a therapeutic protocol: A new promising approach for treating ARDS in patients with coronavirus infection

Background: Coronavirus disease 2019 (COVID-19) is caused by a new severe acute respiratory syndrome Coronavirus. COVID-19 patients are at risk for acute respiratory distress syndrome and death from respiratory failure. Methods: In this study the complete genome of the SARS-CoV-2 reference sequence, geologically isolated types, and Coronavirus related to human diseases were compared by the Molecular Phylogenetic Maximum Likelihood method. The secondary and tertiary structures of the main protease of SARS-CoV were defined as the most similar viruses to SARS-CoV-2, aligned with chimera software. Therefore, considering ineffective antiviral medications used for SARS-CoV and the importance of preventing acute respiratory distress syndrome as the main cause of mortality, 2 strategies were adopted to acquire the most effective drug combination. Results: The results of phylogenic analysis showed that SARS-CoV is the most similar virus to SARS-CoV-2. The secondary structure and superimposing of tertiary structure did not show a significant difference between SARS and SARS-CoV-2 3C-like main protease and the root means square deviation between Cα atoms did not support the difference between the 2 protein structures. Thus, these 2 mechanisms were fostered in accordance with the correlation between acute respiratory distress syndrome-related Coronavirus, angiotensin-converting enzyme 2 on one side and the possible treatments for reducing the respiratory side effects on the other. The analysis of renin-angiotensin system as well as the tested drugs applied to acute respiratory distress syndrome cases, indicated that angiotensin II receptor blockers, angiotensin-converting enzyme inhibitors, and C21 as nonpeptide agonist might possess a promising modality of treatment for acute respiratory distress syndrome. Furthermore, implementing recombinant human ACE2 as a competitive receptor might be an effective way to trap and chelate the SARS-CoV-2 particles. Conclusion: The data suggest that combination therapy of angiotensin II receptor blockers and C21 could be a potential pharmacologic regimen to control and reduce acute respiratory distress syndrome. Moreover, rhACE2 can be recommended as an effective protective antiviral therapy in the treatment of COVID-19 and its complications.

Effect of systemic photobiomodulation in the course of acute lung injury in rats

Acute lung injury (ALI) is a severe, multifactorial lung pathology characterized by diffuse alveolar injury, inflammatory cell infiltration, alveolar epithelial barrier rupture, alveolar edema, and impaired pulmonary gas exchange, with a high rate of mortality; and sepsis is its most common cause. The mechanisms underlying ALI due to systemic inflammation were investigated experimentally by systemic lipopolysaccharide (LPS) administration. Photobiomodulation (PBM) has been showing good results for several inflammatory diseases, but there are not enough studies to support the real benefits of its use, especially systemically. Considering that ALI is a pathology with high morbidity and mortality, we studied the effect of systemic PBM with red light-emitting diode (LED) (wavelength 660 nm; potency 100 mW; energy density 5 J/cm; total energy 15 J; time 150 s) in the management of inflammatory parameters of this disease. For this, 54 male Wistar rats were submitted to ALI by LPS injection (IP) and treated or not with PBM systemically in the tail 2 and 6 h after LPS injection. Data were analyzed by one-way ANOVA followed by Student's Newman-Keuls. Our results point to the beneficial effects of systemic PBM on the LPS-induced ALI, as it reduced the number of neutrophils recruited into the bronchoalveolar lavage, myeloperoxidase activity, and also reduced interleukins (IL) 1β, IL-6, and IL-17 in the lung. Even considering the promising results, we highlight the importance of further studies to understand the mechanisms involved, and especially the dosimetry, so that in near future, we can apply this knowledge in clinical practice.

Acute respiratory distress syndrome in acute pancreatitis

Development of organ failure is one of the major determinants of mortality in patients with acute pancreatitis (AP). Acute respiratory distress syndrome (ARDS) is an important cause of respiratory failure in AP and is associated with high mortality. Pathogenesis of ARDS in AP is incompletely understood. Release of various cytokines plays an important role in development of ARDS in AP. Increased gut permeability due to various toxins, inflammatory mediators, and pancreatic enzymes potentiates lung injury by gut-lymph-lung axis leading on to increased translocation of bacterial endotoxins. Various scoring systems, serum levels of various cytokines and lung ultrasound have been evaluated for prediction of development of ARDS in AP with varying results. Various drugs have shown encouraging results in prevention of ARDS in animal models but these encouraging results in animal models are yet to be confirmed in clinical studies. There is no specific effective treatment for ARDS. Treatment of sepsis and local complications of AP should be done according to the standard management strategies. Lung protective ventilatory strategies are of paramount importance to improve outcome of patients of AP with ARDS and therefore effective coordination between gastroenterologists and intensivists is needed for effective management of these patients.

25-Hydroxycholesterol protects against acute lung injury via targeting MD-2

Acute lung injury (ALI) is mainly caused by uncontrolled inflammatory response, and it remains without effective therapeutic options. 25‐hydroxycholesterol (25HC) has been reported to be a potent regulator of inflammation. The aim of this study was to investigate the effects of 25HC on lipopolysaccharide (LPS)‐induced ALI. C57BL/6 mice were pretreated with 25HC intraperitoneally before intratracheal exposure to LPS. Our results showed that 25HC pretreatment improved survival rate, attenuated the pathological changes of the lung and decreased the release of inflammatory cytokines in mice. Consistently, 25HC reduced expression of Toll‐like receptor (TLR4)‐mediated inflammatory cytokines in vitro. These effects of 25HC were obtained by preventing LPS binding to TLR4 via interaction with myeloid differentiation protein 2 (MD‐2). Crystal structure analysis suggested that 25HC could bind MD‐2 with high affinity into its hydrophobic pocket. Furthermore, LPS‐induced activation of Akt/NF‐κB pathway was partially down‐regulated by 25HC pretreatment. In summary, this study demonstrates that 25HC could inhibit the overwhelming inflammatory response through MD‐2 interaction, which suppresses Akt/NF‐κB signalling pathway. These findings suggest 25HC may be a promising candidate for ALI prevention.

Inflammation and Monocyte Recruitment due to Aging and Mechanical Stretch in Alveolar Epithelium are Inhibited by the Molecular Chaperone 4-phenylbutyrate

Introduction

Ventilator-Induced lung injury (VILI) is a form of acute lung injury that is initiated or exacerbated by mechanical ventilation. The aging lung is also more susceptible to injury. Harmful mechanical stretch of the alveolar epithelium is a recognized mechanism of VILI, yet little is known about how mechanical stretch affects aged epithelial cells. Disruption to Endoplasmic Reticulum (ER) homeostasis results in a condition known as ER stress that leads to disruption of cellular homeostasis, apoptosis, and inflammation. ER stress is increased with aging and other pathological stimuli. We hypothesized that age and mechanical stretch increase alveolar epithelial cells' proinflammatory responses that are mediated by ER stress. Furthermore, we believed that inhibition of this upstream mechanism with 4PBA, an ER stress reducer, alleviates subsequent inflammation and monocyte recruitment.

Methods

Type II alveolar epithelial cells (ATII) were harvested from C57Bl6/J mice 2 months (young) and 20 months (old) of age. The cells were cyclically stretched at 15% change in surface area for up to 24 hours. Prior to stretch, groups were administered 4PBA or vehicle as a control.

Results

Mechanical stretch and age upregulated ER stress and proinflammatory MCP-1/CCL2 and MIP-1β/CCL4 chemokine expression in ATIIs. Age-matched and mismatched monocyte recruitment by ATII conditioned media was also quantified.

Conclusions

Age increases susceptibility to stretch-induced ER stress and downstream inflammatory gene expression in a primary ATII epithelial cell model. Administration of 4PBA attenuated the increased ER stress and proinflammatory responses from stretch and/or age and significantly reduced monocyte migration to ATII conditioned media.

The preventive effect of antiplatelet therapy in acute respiratory distress syndrome: a meta-analysis

Background

Acute respiratory distress syndrome (ARDS) is a life-threatening condition with high mortality that imposes a serious medical burden. Antiplatelet therapy is a potential strategy for preventing ARDS in patients with a high risk of developing this condition. A meta-analysis was performed to investigate whether antiplatelet therapy could reduce the incidence of newly developed ARDS and its associated mortality in high-risk patients.

Methods

The Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, Embase, Medline, and the Web of Science were searched for published studies from inception to 26 October 2017. We included randomized clinical trials, cohort studies and case-control studies investigating antiplatelet therapy in adult patients presenting to the hospital or ICU with a high risk for ARDS. Baseline patient characteristics, interventions, controls and outcomes were extracted. Our primary outcome was the incidence of newly developed ARDS in high-risk patients. Secondary outcomes were hospital and ICU mortality. A random-effects or fixed-effects model was used for quantitative synthesis.

Results

We identified nine eligible studies including 7660 high-risk patients who received antiplatelet therapy. Based on seven observational studies, antiplatelet therapy was associated with a decreased incidence of ARDS (odds ratio (OR) 0.68, 95% confidence interval (CI) 0.52–0.88; I² = 68.4%, p = 0.004). In two randomized studies, no significant difference was found in newly developed ARDS between the antiplatelet groups and placebo groups (OR 1.32, 95% CI 0.72–2.42; I² = 0.0%, p = 0.329). Antiplatelet therapy did not reduce hospital mortality in randomized studies (OR 1.15, 95% CI 0.58–2.27; I² = 0.0%; p = 0.440) or observational studies (OR 0.80, 95% CI 0.62–1.03; I² = 31.9%, p = 0.221).

Conclusions

Antiplatelet therapy did not significantly decrease hospital mortality in high-risk patients. However, whether antiplatelet therapy is associated with a decreased incidence of ARDS in patients at a high risk of developing the condition remains unclear.

Electronic supplementary material

The online version of this article (10.1186/s13054-018-1988-y) contains supplementary material, which is available to authorized users.

The peroxisome proliferator-activated receptor agonist pioglitazone and 5-lipoxygenase inhibitor zileuton have no effect on lung inflammation in healthy volunteers by positron emission tomography in a single-blind placebo-controlled cohort study

Background

Anti-inflammatory drug development efforts for lung disease have been hampered in part by the lack of noninvasive inflammation biomarkers and the limited ability of animal models to predict efficacy in humans. We used ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography (PET) in a human model of lung inflammation to assess whether pioglitazone, a peroxisome proliferator-activated receptor-γ (PPAR-γ) agonist, and zileuton, a 5-lipoxygenase inhibitor, reduce lung inflammation.

Methods

For this single center, single-blind, placebo-controlled cohort study, we enrolled healthy volunteers sequentially into the following treatment cohorts (N = 6 per cohort): pioglitazone plus placebo, zileuton plus placebo, or dual placebo prior to bronchoscopic endotoxin instillation. ¹⁸F-FDG uptake pre- and post-endotoxin was quantified as the Patlak graphical analysis-determined K_i (primary outcome measure). Secondary outcome measures included the mean standard uptake value (SUV_mean), post-endotoxin bronchoalveolar lavage (BAL) cell counts and differentials and blood adiponectin and urinary leukotriene E₄ (LTE₄) levels, determined by enzyme-linked immunosorbent assay, to verify treatment compliance. One- or two-way analysis of variance assessed for differences among cohorts in the outcome measures (expressed as mean ± standard deviation).

Results

Ten females and eight males (29±6 years of age) completed all study procedures except for one volunteer who did not complete the post-endotoxin BAL. K_i and SUV_mean increased in all cohorts after endotoxin instillation (K_i increased by 0.0021±0.0019, 0.0023±0.0017, and 0.0024±0.0020 and SUV_mean by 0.47±0.14, 0.55±0.15, and 0.54±0.38 in placebo, pioglitazone, and zileuton cohorts, respectively, p<0.001) with no differences among treatment cohorts (p = 0.933). Adiponectin levels increased as expected with pioglitazone treatment but not urinary LTE₄ levels as expected with zileuton treatment. BAL cell counts (p = 0.442) and neutrophil percentage (p = 0.773) were similar among the treatment cohorts.

Conclusions

Endotoxin-induced lung inflammation in humans is not responsive to pioglitazone or zileuton, highlighting the challenge in translating anti-inflammatory drug efficacy results from murine models to humans.

Trial registration

ClinicalTrials.gov NCT01174056.

Clinical Implications of Single-Cell Microfluidic Devices for Hematological Disorders

Single-cell microfluidic devices are poised to substantially impact the hematology field by providing a high-throughput and rapid device to analyze disease-mediated biophysical cellular changes in the clinical setting in order to diagnose patients and monitor disease prognosis. In this Feature, we cover recent advances of single-cell microfluidic devices for studying and diagnosing hematological dysfunctions and the clinical impact made possible by these advances.

Beneficial effects of Red Light-Emitting Diode treatment in experimental model of acute lung injury induced by sepsis

Sepsis is a severe disease with a high mortality index and it is responsible for the development of acute lung injury (ALI). We evaluated the effects of light-emitting diode (LED) on ALI induced by sepsis. Balb-c mice were injected with lipopolysaccharide or saline and then irradiated or not with red LED on their tracheas and lungs for 150 s, 2 and 6 h after LPS injections. The parameters were investigated 24 h after the LPS injections. Red LED treatment reduced neutrophil influx and the levels of interleukins 1β, 17 A and, tumor necrosis factor-α; in addition to enhanced levels of interferon γ in the bronchoalveolar fluid. Moreover, red LED treatment enhanced the RNAm levels of IL-10 and IFN-γ. It also partially reduced the elevated oxidative burst and enhanced apoptosis, but it did not alter the translocation of nuclear factor κB, the expression of toll-like receptor 4 (TLR4), as well as, oedema or mucus production in their lung tissues. Together, our data has shown the beneficial effects of short treatment with LED on ALI that are caused by gram negative bacterial infections. It is suggested that LED applications are an inexpensive and non-invasive additional treatment for sepsis.

Acute respiratory distress syndrome

Since its first description, the acute respiratory distress syndrome (ARDS) has been acknowledged to be a major clinical problem in respiratory medicine. From July 2015 to July 2016 almost 300 indexed articles were published on ARDS. This review summarises only eight of them as an arbitrary overview of clinical relevance: definition and epidemiology, risk factors, prevention and treatment. A strict application of definition criteria is crucial, but the diverse resource-setting scenarios foster geographic variability and contrasting outcome data. A large international multicentre prospective cohort study including 50 countries across five continents reported that ARDS is underdiagnosed, and there is potential for improvement in its management. Furthermore, epidemiological data from low-income countries suggest that a revision of the current definition of ARDS is needed in order to improve its recognition and global clinical outcome. In addition to the well-known risk-factors for ARDS, exposure to high ozone levels and low vitamin D plasma concentrations were found to be predisposing circumstances. Drug-based preventive strategies remain a major challenge, since two recent trials on aspirin and statins failed to reduce the incidence in at-risk patients. A new disease-modifying therapy is awaited: some recent studies promised to improve the prognosis of ARDS, but mortality and disabling complications are still high in survivors in intensive care.

Lugrandoside attenuates LPS-induced acute respiratory distress syndrome by anti-inflammation and anti-apoptosis in mice

This study aimed to investigate the protective effects and specific mechanisms of lugrandoside (LG) on lipopolysaccharides (LPS)-induced acute respiratory distress syndrome (ARDS). LG is a novel phenylpropanoid glycoside with many biological properties, isolated from the culinary leaves of Digitalis lutea L. and Digitalis grandiflora Miller. The primary indicators to assess the lung injury were infiltration of inflammatory cells; pulmonary edema; expression of proinflammatory cytokines, cyclo-oxygenase 2, and intracellular adhesion molecule 1; activation of nuclear factor-κB pathways; and cellular apoptosis. The results showed that LG evidently alleviated the inflammatory response, decreased the apoptosis of alveolar macrophages, and improved the lung injury in mice with LPS-induced ARDS. In conclusion, LG improved LPS-induced ARDS by anti-inflammation and anti-apoptosis and might be a promising pharmacological therapy for ARDS.

Acute Lung Injury: A Clinical and Molecular Review

CONTEXT

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are a continuum of lung changes arising from a wide variety of lung injuries, frequently resulting in significant morbidity and frequently in death. Research regarding the molecular pathophysiology of ALI/ARDS is ongoing, with the aim toward developing prognostic molecular biomarkers and molecular-based therapy.

OBJECTIVE

To review the clinical, radiologic, and pathologic features of ALI/ARDS; and the molecular pathophysiology of ALI/ARDS, with consideration of possible predictive/prognostic molecular biomarkers and possible molecular-based therapies.

DATA SOURCES

Examination of the English-language medical literature regarding ALI and ARDS.

CONCLUSIONS

ARDS is primarily a clinicoradiologic diagnosis; however, lung biopsy plays an important diagnostic role in certain cases. A significant amount of progress has been made in the elucidation of ARDS pathophysiology and in predicting patient response, however, currently there is no viable predictive molecular biomarkers for predicting the severity of ARDS, or molecular-based ARDS therapies. The proinflammatory cytokines TNF-α (tumor necrosis factor α), interleukin (IL)-1β, IL-6, IL-8, and IL-18 are among the most promising as biomarkers for predicting morbidity and mortality.