Budesonide ameliorates lung injury induced by large volume ventilation

Future directions in ventilator-induced lung injury associated cognitive impairment: a new sight

Mechanical ventilation is a widely used short-term life support technique, but an accompanying adverse consequence can be pulmonary damage which is called ventilator-induced lung injury (VILI). Mechanical ventilation can potentially affect the central nervous system and lead to long-term cognitive impairment. In recent years, many studies revealed that VILI, as a common lung injury, may be involved in the central pathogenesis of cognitive impairment by inducing hypoxia, inflammation, and changes in neural pathways. In addition, VILI has received attention in affecting the treatment of cognitive impairment and provides new insights into individualized therapy. The combination of lung protective ventilation and drug therapy can overcome the inevitable problems of poor prognosis from a new perspective. In this review, we summarized VILI and non-VILI factors as risk factors for cognitive impairment and concluded the latest mechanisms. Moreover, we retrospectively explored the role of improving VILI in cognitive impairment treatment. This work contributes to a better understanding of the pathogenesis of VILI-induced cognitive impairment and may provide future direction for the treatment and prognosis of cognitive impairment.

MCC950 Ameliorates Acute Exogenous Lipoid Pneumonia Induced by Sewing Machine Oil in Rats via the NF-κB/NLRP3 Inflammasome Pathway

BACKGROUND/AIM

Acute exogenous lipoid pneumonia (AELP) is a rare disorder caused by intake of lipid formulations and is often underdiagnosed. Meanwhile, the mechanism of AELP is still underlying. MCC950, was previously found to significantly suppress the release of inflammatory cytokines IL-18 and IL-1β. However, the effect of MCC950 on AELP induced by sewing machine oil has not been reported.

MATERIALS AND METHODS

The NLRP3, NF-[Formula: see text]B p65, caspase-1 and IL-1β expression in lung tissues were compared between a rat model of AELP and control rats using western blotting and real-time quantitative assay. Moreover, haematoxylin and eosin (H&E) staining was performed to elucidate the mechanisms by which MCC950 ameliorates sewing machine oil-induced AELP in vivo.

RESULTS

MCC950 reduced the expression of NF-[Formula: see text]B p65 in the lung samples of the treatment group and further down-regulated the NLRP3 and caspase-1 levels while inhibited the production of IL-1β. Besides, decreases in inflammatory cell infiltration in the lung were shown using H&E staining.

CONCLUSION

MCC950 ameliorates sewing machine oil-induced acute exogenous lipoid pneumonia in rats through inhibition of the NF-[Formula: see text]B/NLRP3 inflammasome pathway.

Budesonide-Loaded Bilosomes as a Targeted Delivery Therapeutic Approach Against Acute Lung Injury in Rats

Budesonide (BUD), a glucocorticoids drug, inhibits all steps in the inflammatory response. It can reduce and treat inflammation and other symptoms associated with acute lung injury such as COVID-19. Loading BUD into bilosomes could boost its therapeutic activity, and lessen its frequent administration and side effects. Different bilosomal formulations were prepared where the independent variables were lipid type (Cholesterol, Phospholipon 80H, L-alpha phosphatidylcholine, and Lipoid S45), bile salt type (Na cholate and Na deoxycholate), and drug concentration (10, 20 mg). The measured responses were: vesicle size, entrapment efficiency, and release efficiency. One optimum formulation (composed of cholesterol, Na cholate, and 10 mg of BUD) was selected and investigated for its anti-inflammatory efficacy in vivo using Wistar albino male rats. Randomly allocated rats were distributed into four groups: The first: normal control group and received intranasal saline, the second one acted as the acute lung injury model received intranasal single dose of 2 mg/kg potassium dichromate (PD). Whereas the third and fourth groups received the market product (Pulmicort® nebulising suspension 0.5 mg/ml) and the optimized formulation (0.5 mg/kg; intranasal) for 7 days after PD instillation, respectively. Results showed that the optimized formulation decreased the pro-inflammatory cytokines TNF-α, and TGF-β contents as well as reduced PKC content in lung. These findings suggest the potentiality of BUD-loaded bilosomes for the treatment of acute lung injury with the ability of inhibiting the pro-inflammatory cytokines induced COVID-19.

Long-term exposure to house dust mites accelerates lung cancer development in mice

BACKGROUND

Individuals with certain chronic inflammatory lung diseases have a higher risk of developing lung cancer (LC). However, the underlying mechanisms remain largely unknown. Here, we hypothesized that chronic exposure to house dust mites (HDM), a common indoor aeroallergen associated with the development of asthma, accelerates LC development through the induction of chronic lung inflammation (CLI).  METHODS: The effects of HDM and heat-inactivated HDM (HI-HDM) extracts were evaluated in two preclinical mouse models of LC (a chemically-induced model using the carcinogen urethane and a genetically-driven model with oncogenic KrasG12D activation in lung epithelial cells) and on murine macrophages in vitro. Pharmacological blockade or genetic deletion of the Nod-like receptor family pyrin domain-containing protein 3 (NLRP3) inflammasome, caspase-1, interleukin-1β (IL-1β), and C-C motif chemokine ligand 2 (CCL2) or treatment with an inhaled corticosteroid (ICS) was used to uncover the pro-tumorigenic effect of HDM.  RESULTS: Chronic intranasal (i.n) instillation of HDM accelerated LC development in the two mouse models. Mechanistically, HDM caused a particular subtype of CLI, in which the NLRP3/IL-1β signaling pathway is chronically activated in macrophages, and made the lung microenvironment conducive to tumor development. The tumor-promoting effect of HDM was significantly decreased by heat treatment of the HDM extract and was inhibited by NLRP3, IL-1β, and CCL2 neutralization, or ICS treatment.

CONCLUSIONS

Collectively, these data indicate that long-term exposure to HDM can accelerate lung tumorigenesis in susceptible hosts (e.g., mice and potentially humans exposed to lung carcinogens or genetically predisposed to develop LC).

Annexin A1 peptide Ac2-26 mitigates ventilator-induced lung injury in acute respiratory distress syndrome rats and partly depended on the endothelial nitric oxide synthase pathway

PURPOSE

Although mechanical ventilation is an essential support for acute respiratory distress syndrome (ARDS), ventilation also leads to ventilator-induced lung injury (VILI). This study aimed to estimate the effect and mechanism of Annexin A1 peptide (Ac2-26) on VILI in ARDS rats.

METHODS

Thirty-two rats were randomized into the sham (S), mechanical ventilation (V), mechanical ventilation/Ac2-26 (VA), and mechanical ventilation/Ac2-26/L-NIO (VAL) groups. The S group only received anesthesia, and the other three groups received endotoxin and then ventilation for 4 h. Rats in the V, VA and VAL groups received saline, Ac2-26, and A c2-26/N5-(1-iminoethyl)-l-ornithine (L-NIO), respectively.

RESULTS

All indexes deteriorated in the V, VA and VAL groups compared with the S group. Compared with V group, the PaO2/FiO2 ratio was increased, but the wet-to-dry weight ratio and protein levels in bronchoalveolar lavage fluid were decreased in the VA group. The inflammatory cells and proinflammatory factors were reduced by Ac2-26. The oxidative stress response, lung injury and apoptosis were also decreased by Ac2-26 compared to V group. All improvements of Ac2-26 were partly reversed by L-NIO.

CONCLUSIONS

Ac2-26 mitigates VILI in ARDS rats and partly depended on the endothelial nitric oxide synthase pathway.

Acinetobacter baumannii among Patients Receiving Glucocorticoid Aerosol Therapy during Invasive Mechanical Ventilation, China

Acinetobacter baumannii is a nosocomial pathogen associated with severe illness and death. Glucocorticoid aerosol is a common inhalation therapy in patients receiving invasive mechanical ventilation. We conducted a prospective cohort study to analyze the association between glucocorticoid aerosol therapy and A. baumannii isolation from ventilator patients in China. Of 497 enrolled patients, 262 (52.7%) received glucocorticoid aerosol, and A. baumannii was isolated from 159 (32.0%). Glucocorticoid aerosol therapy was an independent risk factor for A. baumannii isolation (hazard ratio 1.5, 95% CI 1.02-2.28; p = 0.038). Patients receiving glucocorticoid aerosol had a higher cumulative hazard for A. baumannii isolation and analysis showed that glucocorticoid aerosol therapy increased A. baumannii isolation in most subpopulations. Glucocorticoid aerosol was not a direct risk factor for 30-day mortality, but A. baumannii isolation was independently associated with 30-day mortality in ventilator patients. Physicians should consider potential A. baumannii infection when prescribing glucocorticoid aerosol therapy.

Efficacy of Colchicine and Budesonide in Improvement Outcomes of Patients with Coronavirus Infection 2019 in Damascus, Syria: A Randomized Control Trial

COVID-19 was reported in China in 2019 and has spread worldwide. Transmission occurs through respiratory secretions and, less commonly, through contaminated surfaces. The severity of the disease can range from asymptomatic to acute respiratory distress syndrome (ARDS). In this study, we aim to investigate the efficacy of two agents (oral colchicine and budesonide inhaler) in COVID-19 infection management, compared with supportive care alone. 77 patients were admitted to the isolation section of Al Assad University Hospital, between the 1st of August and the 30th of August. A total of 49 patients were included in this randomized control trial, after excluding ineligible patients. The random sample was divided into three groups; the first group was supportive care plus colchicine, the second group was supportive care plus budesonide inhaler, and the control group was supportive care alone. PaO2/FiO2 was improved in the budesonide group, higher than the supportive and colchicine groups. The median hospitalization days were shorter when using colchicine or budesonide, opposed to supportive care alone (8 vs 10 days, respectively). 34 patients (69.3%) were discharged, and 27 patients (55.1%) were followed up until they were weaned from oxygen and made a complete recovery. There was a significant decrease in mortality with colchicine (3 patients; 21.4%) compared with supportive care (7 patients; 33.3%) and the budesonide group (5 patients; 35.7%).

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.

Astragaloside IV Attenuates Polymicrobial Sepsis-Induced Cardiac Dysfunction in Rats via IKK/NF-κB Pathway

OBJECTIVE

To evaluate the protective effects of Astragaloside IV (AST) in a rat model of myocardial injury induced by cecal ligation and puncture (CLP).

METHODS

The model of sepsis-induced cardiac dysfunction was induced by CLP. Using a random number table, 50 specific pathogen free grade of Sprague Dawley rats were randomized into 5 groups: the sham group (sham), the model group (CLP, 18 h/72 h) and AST group (18 h/72 h). Except the sham group, the rats in other groups received CLP surgery to induce sepsis. CLP groups received intragastric administration with normal saline after CLP. AST groups received intragastric administration with AST solution (40 mg/kg) once a day. The levels of inflammatory mediators and oxidative stress markers in the serum of the septic rats were determined via enzyme-linked immunosorbent assay (ELISA) at different time point, such as interleukin 6 (IL-6), IL-10, high mobility group box-1 protein B1 (HMGB-1), superoxide dismutase (SOD), and malondialdehyde (MDA). Cardiac function was determined by echocardiography. Moreover, changes in myocardial pathology were evaluated using hematoxylin and eosin staining. The levels of lactate dehydrogenase (LDH) and creatine kinase-MB (CK-MB) were analysed to determine the status of CLP-induced myocardium. In addition, the apotosis of myocardial cells was analysed by terminal-deoxynucleoitidyl transferase mediated nick end labeling (TUNEL). The protein levels of B-cell lymphoma-2 (Bcl-2), Bcl-2-associated X (Bax), IκB kinase α (IKKα), nuclear factor kappa B p65 (NF-κB p65) were detected by Western blot analysis. Moreover, survival rate was investigated.

RESULTS

AST improved the survival rate of CLP-induced rats by up to 33.3% (P<0.05). The cardioprotective effect of AST was observed by increased ejection fraction, fractional shortening and left ventricular internal diameter in diastole respectively (P<0.01 or P<0.05). Subsequently, AST attenuated CLP-induced myocardial apoptosis and the ratio of Bcl-2/Bax in the myocardium, as well as the histological alterations of myocardium (P<0.01 or P<0.05); the generation of inflammatory cytokines (IL-6, IL-10, HMGB-1) and oxidative stress markers (SOD, MDA) in the serum was significantly alleviated (P<0.01 or P<0.05). On the other hand, AST markedly suppressed CLP-induced accumulation of IKK-α and NF-κB p65 subunit phosphorylation (P<0.01 or P<0.05).

CONCLUSIONS

AST plays a significant protective role in sepsis-induced cardiac dysfunction and survival outcome. The possible mechanism of cardioprotection is dependent on the activation of the IKK/NF-κB pathway in cardiomyocytes.

Attenuation of ventilator-induced lung injury through suppressing the pro-inflammatory signaling pathways: A review on preclinical studies

Mechanical ventilation (MV) is a relatively common medical intervention in ICU patients. The main side effect of MV is the so-called "ventilator-induced lung injury" (VILI). The pathogenesis of VILI is not completely understood; however, it has been reported that MV might be associated with up-regulation of various inflammatory mediators within the lung tissue and that these mediators might act as pathogenic factors in lung tissue injury. One potential mechanism for the generation of inflammatory mediators is through the release of endogenous molecules known as damage associated molecular patterns (DAMPs). These molecules are released from injured tissues and can bind to pattern recognition receptors (PRRs). PRR activation generally leads to the production and release of inflammation-related molecules including innate immune cytokines and chemokines. It has been suggested that blocking DAMP/PRR signaling pathways might diminish the progression of VILI. Herein, we review the latest findings with regard to the effects of DAMP/PRRs and their blockade, as well as the potential therapeutic targets and future research directions in VILI. Results of studies performed on human samples, animal models of disease, as well as relevant in vitro systems will be discussed.

Corticosteroids in Acute Lung Injury: The Dilemma Continues

Acute lung injury (ALI) represents a serious heterogenous pulmonary disorder with high mortality. Despite improved understanding of the pathophysiology, the efficacy of standard therapies such as lung-protective mechanical ventilation, prone positioning and administration of neuromuscular blocking agents is limited. Recent studies have shown some benefits of corticosteroids (CS). Prolonged use of CS can shorten duration of mechanical ventilation, duration of hospitalization or improve oxygenation, probably because of a wide spectrum of potentially desired actions including anti-inflammatory, antioxidant, pulmonary vasodilator and anti-oedematous effects. However, the results from experimental vs. clinical studies as well as among the clinical trials are often controversial, probably due to differences in the designs of the trials. Thus, before the use of CS in ARDS can be definitively confirmed or refused, the additional studies should be carried on to determine the most appropriate dosing, timing and choice of CS and to analyse the potential risks of CS administration in various groups of patients with ARDS.

Endothelial Progenitor Cells Attenuate Ventilator-Induced Lung Injury with Large-Volume Ventilation

Ventilator-induced lung injury (VILI) is a common complication that results from treatment with mechanical ventilation (MV) in acute respiratory distress syndrome (ARDS) patients. The present study investigated the effect of endothelial progenitor cell (EPC) transplantation on VILI. Wistar rats were divided into three groups (n = 8): sham (S), VILI model (V) induced by tidal volume ventilation (17 mL/kg), and VILI plus EPC transplantation (VE) groups. The lung PaO₂/FiO₂ ratio, pulmonary wet-to-dry (W/D) weight ratio, number of neutrophils, total protein, neutrophil elastase level, and inflammatory cytokines in bronchoalveolar lavage fluid (BALF) and serum were examined. Furthermore, the histological and apoptotic analysis, and lung tissue protein expression analysis of Bax, Bcl-2, cleaved caspase-3, matrix metalloproteinase (MMP)-9, total nuclear factor kappa B (total-NF-κB), phosphorylated NF-κB (phospho-NF-κB) and myosin light chain (MLC) were performed. The ventilation-induced decrease in PaO₂/FiO₂ ratio, and the increase in W/D ratio and total protein concentration were prevented by the EPC transplantation. The EPC transplantation (VE group) significantly attenuated the VILI-induced increased expression of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-8, MMP-9, phospho-NF-κB and MLC, neutrophil elastase levels and neutrophil counts in BALF. In addition, the anti-inflammatory factor IL-10 increased in the VE group. Furthermore, pulmonary histological injury and apoptosis (TUNEL-positive cells, increase in Bax and cleaved caspase-3) were considerably diminished by the EPC transplantation. The EPC transplantation ameliorated the VILI. The mechanism may be primarily through the improvement of epithelial permeability, inhibition of local and systemic inflammation, and reduction in apoptosis.

Alpha 1-antitrypsin for treating ventilator-associated lung injury in acute respiratory distress syndrome rats

Purpose: Mechanical ventilation (MV) is an essential life support tool for patients with acute respiratory distress syndrome (ARDS). However, MV for ARDS can result in ventilator-induced lung injury (VILI). This study aimed to assess whether alpha 1-antitrypsin (AAT) can reduce VILI in ARDS rats. Materials and Methods: Rats were randomly divided into five groups: the sham (S) group, MV (V) group, lipopolysaccharide (LPS) (L) group, MV/LPS (VL) group and MV/AAT (VA) group. Rats in the S group were anesthetized. The rats in the L group received LPS but not ventilation, the rats in the V group received only MV, and the rats in the VL and VA groups received LPS and MV. Additionally, the rats in the VA group were treated with AAT, and the other rats were injected with saline. The PaO₂/FiO₂ ratio and the wet/dry weight were assessed. The total protein and neutrophil elastase concentrations and the neutrophil and macrophage counts in bronchoalveolar lavage fluid (BALF) were evaluated. Proinflammatory factors in BALF and ICAM-1 and MIP-2 in serum were also tested. Furthermore, the oxidative stress response was detected, and histological injury and apoptosis were evaluated. Results: All the rats in the V, L and VL groups had significant lung injury, with the VL group exhibiting the most severe injury. Compared with the findings in the VL group, AAT significantly upregulated the PaO₂/FiO₂ ratio but decreased the wet/dry weight ratio and protein levels in BALF. AAT also reduced proinflammatory cytokine levels and inflammatory cell counts in BALF. Lung tissue injury and cell apoptosis were mitigated by AAT. Conclusions: AAT ameliorated VILI in ARDS rats. The protection conferred by AAT may be associated with the anti-inflammatory, antioxidative stress response and anti-apoptotic effects of AAT.

Intranasal Application of Budesonide Attenuates Lipopolysaccharide-Induced Acute Lung Injury by Suppressing Nucleotide-Binding Oligomerization Domain-Like Receptor Family, Pyrin Domain-Containing 3 Inflammasome Activation in Mice

Aim

To investigate the protective effects of budesonide against lipopolysaccharide- (LPS-) induced acute lung injury (ALI) in a murine model and its underlying mechanism.

Methods

Adult male C57BL/6 mice were divided into three groups: control, ALI, and ALI + budesonide groups. LPS (5 mg/kg) was intratracheally injected to induce ALI in mice. Budesonide (0.5 mg/kg) was intranasally given 1 h before LPS administration in the ALI + budesonide group. Twelve hours after LPS administration, all mice were sacrificed. Hematoxylin-eosin staining and pathological scores were used to evaluate pathological injury. Bronchoalveolar lavage was performed. The numbers of total cells, neutrophils, and macrophages in the bronchoalveolar lavage fluid (BALF) were counted. Enzyme-linked immunosorbent assay was employed to detect the proinflammatory cytokines in BALF and serum, including tumor necrosis factor- (TNF-) α, monocyte chemoattractant protein- (MCP-) 1, and interleukin- (IL-) 1β. The expression of the nucleotide-binding oligomerization domain-like receptor family, pyrin domain-containing 3 (NLRP3) inflammasome was detected by western blotting. A lethal dose of LPS (40 mg/kg, intraperitoneally) was injected to evaluate the effects of budesonide on survival rates.

Results

Budesonide pretreatment dramatically attenuated pathological injury and reduced pathological scores in mice with ALI. Budesonide pretreatment obviously reduced the numbers of total cells, neutrophils, and macrophages in the BALF of mice with ALI. Additionally, budesonide dramatically reduced TNF-α and MCP-1 expression in the BALF and serum of mice with ALI. Budesonide significantly suppressed NLRP3 and pro-caspase-1 expression in the lung and reduced IL-1β content in the BALF, indicating that budesonide inhibited the activation of the NLRP3 inflammasome. Furthermore, we found that budesonide improved the survival rates of mice with ALI receiving a lethal dose of LPS.

Conclusion

Suppression of NLRP3 inflammasome activation in mice via budesonide attenuated lung injury induced by LPS in mice with ALI.

Interleukin-5, interleukin-6, interferon induced protein-10, procalcitonin and C-reactive protein among mechanically ventilated severe community-acquired viral and bacterial pneumonia patients

BACKGROUND

The serum cytokine levels among 45 mechanically ventilated, intensive care unit (ICU)-treated severe community-acquired pneumonia (SCAP) patients with known microbial etiology in three different etiology groups were assessed.

METHODS

Blood samples for C-reactive protein (CRP), procalcitonin (PCT), interleukin (IL)-5, IL-6, IL-10, human interferon gamma induced protein (IP)-10, and TNF-α (tumor necrosis factor alpha) were collected at time points 0, 12, 24, 48, 72 and 96 h after study inclusion.

RESULTS

There were 21 (43%) pure bacterial infections (bacterial group, BG), 5 (10%) pure viral infections (viral group, VG), and 19 (39%) mixed bacterial-viral infections (mixed group, MG) among 45 mechanically ventilated SCAP patients. CRP and PCT levels were significantly higher in the MG and values decreased with time in all groups. PCT differed also in time and group analysis (P = 0.001), the highest being in the MG. IL-5 levels were significantly higher in the VG compared to others (Ptime = 0.001, Pgroup = 0.051 and Ptimexgroup = 0.016). IL-6 and IP-10 levels decreased over time (Ptime = 0.003 and Ptime = 0.021), but there were no differences between groups.

CONCLUSION

SCAP patients with viral etiology have higher IL-5 levels. Patients with mixed viral and bacterial group have higher PCT compared to other etiologies.

Cross-sectional analysis on publication status and age representation of clinical studies addressing mechanical ventilation and ventilator-induced lung injury in infants and children

OBJECTIVES

We determined the number and time-to-public availability of study results of published and unpublished clinical studies in paediatric mechanical ventilation (MV) and ventilator-induced lung injury (VILI), which were registered as completed on ClinicalTrials.gov. Furthermore, we explored the pattern of represented research study subtopics and the corresponding study populations.

SETTING

Literature search based on ClinicalTrials.gov, PubMed and Google Scholar from 9 July 2017 to 27 September 2017.

PRIMARY AND SECONDARY OUTCOME MEASURES

Assessment, if studies included in our analysis had been published. Assessment of primary research focus, patient enrolment and age representation of the analysed studies.

RESULTS

We identified n=109 registered and completed clinical studies on paediatric MV and VILI (enrolment: 22 233 participants). 71% were published, including data from 18 647 subjects. 29% of studies were unpublished, containing data from 3586 subjects. Median time-to-public availability of study results was 22 (IQR, 12.8-41.5) months. The most important study subtopics were biophysical and technical aspects of MV (32 studies), administration of drugs to mitigate VILI through various mechanisms (40 studies) and diagnostic procedures (16 studies). n=66/109 (61%) studies exclusively focused on children below 1 year of age and n=2/109 (2%) exclusively on children between 1 and 14 years.

CONCLUSIONS

One-third of clinical studies in paediatric MV and VILI registered as completed on ClinicalTrials.gov remained unpublished and contained data on 3586 study participants. The overall median time-to-public availability of study results was longer than the deadline of 12 months mandated by the Food and Drug Administration Amendment Act of 2007. Important and clinically relevant research study subtopics were represented in the research questions investigated in paediatric MV and VILI. The study population was skewed towards children younger than 1 year which indicates, that there is a substantial need for clinical VILI research in older children.

Inhibition of chlorine-induced airway fibrosis by budesonide

Chlorine is a chemical threat agent that can be harmful to humans. Acute inhalation of high levels of chlorine results in the death of airway epithelial cells and can lead to persistent adverse effects on respiratory health, including airway remodeling and hyperreactivity. We previously developed a mouse chlorine exposure model in which animals developed inflammation and fibrosis in large airways. In the present study, examination by laser capture microdissection of developing fibroproliferative lesions in FVB/NJ mice exposed to 240 ppm-h chlorine revealed upregulation of genes related to macrophage function. Treatment of chlorine-exposed mice with the corticosteroid drug budesonide daily for 7 days (30-90 μg/mouse i.m.) starting 1 h after exposure prevented the influx of M2 macrophages and the development of airway fibrosis and hyperreactivity. In chlorine-exposed, budesonide-treated mice 7 days after exposure, large airways lacking fibrosis contained extensive denuded areas indicative of a poorly repaired epithelium. Damaged or poorly repaired epithelium has been considered a trigger for fibrogenesis, but the results of this study suggest that inflammation is the ultimate driver of fibrosis in our model. Examination at later times following 7-day budesonide treatment showed continued absence of fibrosis after cessation of treatment and regrowth of a poorly differentiated airway epithelium by 14 days after exposure. Delay in the start of budesonide treatment for up to 2 days still resulted in inhibition of airway fibrosis. Our results show the therapeutic potential of budesonide as a countermeasure for inhibiting persistent effects of chlorine inhalation and shed light on mechanisms underlying the initial development of fibrosis following airway injury.

Desflurane Attenuates Ventilator-Induced Lung Injury in Rats with Acute Respiratory Distress Syndrome

Ventilator-induced lung injury aggravates the existing lung injury. This study investigated the effect of desflurane on VILI in a rat model of acute respiratory distress syndrome. Forty-eight rats were randomized into a sham (S) group, control (C) group, lipopolysaccharide/ventilation (LV) group, lipopolysaccharide/ventilation/desflurane (LVD) group, or lipopolysaccharide/low ventilation with and without desflurane (LLV and LLVD) groups. Rats in the S group received anesthesia only. Rats in the LV and LVD groups received lipopolysaccharide and were ventilated with a high tidal volume. Rats in LLV and LLVD groups were treated as the LV and LVD groups and ventilated with a low tidal volume. PaO₂/FiO₂, lung wet-to-dry weight ratios, concentrations of inflammatory factors in serum and BALF, histopathologic analysis of lung tissue, and levels of nuclear factor- (NF-) κB protein in lung tissue were investigated. PaO₂/FiO₂ was significantly increased by desflurane. Total cell count, macrophages, and neutrophils in BALF and proinflammatory factors in BALF and serum were significantly decreased by desflurane, while IL-10 was increased. The histopathological changes and levels of NF-κB protein in lung tissue were decreased by desflurane. The results indicated that desflurane ameliorated VILI in a rat model of acute respiratory distress syndrome.

Preventive Effects of Velvet Antler (Cervus elaphus) against Lipopolysaccharide-Induced Acute Lung Injury in Mice by Inhibiting MAPK/NF-κB Activation and Inducing AMPK/Nrf2 Pathways

Velvet antler (Cervus elaphus) is a typical traditional animal medicine. It is considered to have various pharmacological effects including stimulation of the immune system, increase in the physical strength, and enhancement of sexual function. This paper aims to investigate the aqueous extract of velvet antler (AVA) in the mouse models of LPS-induced ALI. Inhibition of NO, TNF-α, IL-1β, IL-6, and IL-10 productions contributes to the attenuation of LPS-induced lung inflammation by AVA. A 5-day pretreatment of AVA prevented histological alterations and enhanced antioxidant enzyme activity in lung tissues. AVA significantly reduced the material (total number of cells and proteins) in the BALF. Western blot analysis revealed that the expression of iNOS and COX-2 and phosphorylation of IκB-α and MAPKs proteins are blocked in LPS-stimulated macrophages as well as LPS-induced lung injury in mice. Consistent with this concept, the phosphorylation of CaMKKβ, LKB1, AMPK, Nrf2, and HO-1 was activated after AVA treatment. The results from this study indicate AVA has anti-inflammatory effects in vivo and AVA is a potential model for the development of health food. In addition, its pathways may be at least partially associated with inhibiting MAPK/NF-κB activation and upregulating AMPK/Nrf2 pathways and the regulation of antioxidant enzyme activity.

Alpha 1-antitrypsin ameliorates ventilator-induced lung injury in rats by inhibiting inflammatory responses and apoptosis

Mechanical ventilation is extensively used to treat patients with lung injury but may result in ventilator-induced lung injury (VILI). The present study investigated the protective effect of alpha 1-antitrypsin (AAT) on VILI. Adult male rats were subjected to sham, ventilation + saline, or ventilation + AAT treatment and lung injuries were evaluated. Peripheral blood and bronchoalveolar lavage fluid (BALF) were obtained to assess systemic and local inflammatory responses, respectively. Mechanical ventilation resulted in lung injury, as evidenced by histological abnormalities as well as elevations in PaO₂/FiO₂ ratio, the wet-to-dry weight ratio, and the BALF level of proteins. The intravenous administration of AAT significantly improved these parameters of lung function, suggesting a protective role of AAT in VILI. Mechanistically, ventilator-induced inflammation was effectively reduced by AAT, as evidenced by decreases in BALF neutrophil counts, BALF cytokines, and serum adhesion factors. In contrast, anti-inflammatory interleukin-10 in BALF was increased in response to AAT. AAT treatment also inhibited the expression of nuclear factor-κB, Bax, and cleaved caspase-3 while promoting Bcl-2 expression in ventilator-injured lung tissues. AAT treatment can ameliorate VILI by inhibiting inflammatory mediator production and apoptosis. Impact statement Mechanical ventilation has been commonly used to treat patients with lung injury but may result in ventilator-induced lung injury (VILI). Few effective treatment options are currently available to reduce VILI. Alpha 1-antitrypsin (AAT) is an inhibitor of serine protease with anti-inflammatory and antiapoptotic properties, suggesting a possible role in attenuating lung injury. The present study demonstrates that AAT inhibits the development of VILI by modulating inflammation- and apoptosis-related protein expression. Therefore, AAT may be a novel therapeutic agent for acute respiratory distress syndrome patients undergoing mechanical ventilation.

A Pilot Study of Nebulized Heparin for Prevention of Ventilator Induced Lung Injury: Comparative Effects with an Inhaled Corticosteroid

Background:

Ventilator-induced lung injury (VILI) is a side effect of mechanical ventilation. Lung inflammation and pulmonary activation of coagulation are induced by mechanical stress. Clinical and preclinical studies show that heparin possesses anti-inflammatory properties. Therefore, we assessed the effects of nebulized heparin in VILI.

Methods:

Sixty critically ill adult patients who require mechanical ventilation for more than 48 h were included in this prospective, nonrandomized controlled study. Patients received nebulized heparin (10,000 U every 6 h) for 5 days. The matched control group received nebulized budesonide as routine practice in our center. This study assessed changes in partial pressure of oxygen to inspired fraction of oxygen ratio (PaO₂/FiO₂) and rapid shallow breathing index (RSBI) during the study as primary endpoints.

Results:

The average daily PaO₂/FiO₂ ratio was not statistically significant between both groups (187 ± 11.6 vs. 171 ± 11.6, P = 0.35). The RSBI also did not differ between groups (P = 0.58). Heparin administration was associated with a higher number of ventilator-free days among survivors but not significantly (7.7 ± 10.6 vs. 5.1 ± 8, 95% confidence interval − 2.2–7.5, P = 0.28). Successful weaning from mechanical ventilation was higher in the heparin group (P = 0.42). We did not observe any serious or increased adverse effects from nebulized heparin.

Conclusion:

The results of this study show that the overall effectiveness of nebulized heparin is at least as comparable with a potent corticosteroid (budesonide). Heparin could be a safe and effective modality for patients who at risk of VILI.

Endothelial cell signaling and ventilator-induced lung injury: molecular mechanisms, genomic analyses, and therapeutic targets

Mechanical ventilation is a life-saving intervention in critically ill patients with respiratory failure due to acute respiratory distress syndrome (ARDS). Paradoxically, mechanical ventilation also creates excessive mechanical stress that directly augments lung injury, a syndrome known as ventilator-induced lung injury (VILI). The pathobiology of VILI and ARDS shares many inflammatory features including increases in lung vascular permeability due to loss of endothelial cell barrier integrity resulting in alveolar flooding. While there have been advances in the understanding of certain elements of VILI and ARDS pathobiology, such as defining the importance of lung inflammatory leukocyte infiltration and highly induced cytokine expression, a deep understanding of the initiating and regulatory pathways involved in these inflammatory responses remains poorly understood. Prevailing evidence indicates that loss of endothelial barrier function plays a primary role in the development of VILI and ARDS. Thus this review will focus on the latest knowledge related to 1) the key role of the endothelium in the pathogenesis of VILI; 2) the transcription factors that relay the effects of excessive mechanical stress in the endothelium; 3) the mechanical stress-induced posttranslational modifications that influence key signaling pathways involved in VILI responses in the endothelium; 4) the genetic and epigenetic regulation of key target genes in the endothelium that are involved in VILI responses; and 5) the need for novel therapeutic strategies for VILI that can preserve endothelial barrier function.