Acute Respiratory Distress Research Articles

Curcumol derivatives exhibit ameliorating effects on lipopolysaccharide-induced acute lung injury: Synthesis, biological evaluation, structure–activity relationship and action mechanism

Acute lung injury (ALI) is an intricate clinical disease marked by high mortality and a sudden start. Currently, although there are no specific therapeutics for ALI, the administration of anti-inflammatory drugs is a promising treatment strategy. Curcumol, a terpenoid natural product, has demonstrated significant anti-inflammatory activity. Herein, we designed and synthesised 42 curcumol derivatives using curcumol as the core scaffold. These derivatives underwent in vitro screening for anti-inflammatory activity, and their structure–activity relationship was assessed. Among them, derivative 2 exhibited potent anti-inflammatory potential, inhibiting the expression of inflammatory markers at the nanomolar level. In addition, its water solubility was considerably improved, thereby laying the foundation for enhanced druggability. Derivative 2 also ameliorated lipopolysaccharide (LPS)-induced ALI and reduced pulmonary inflammation at a dose of 5 mg/kg. Proteomics analysis revealed that the anti-inflammatory effect of this compound primarily involved the mTOR signalling pathway. Furthermore, molecular docking and cellular thermal shift assays indicated that GSK3β is a critical target of action of derivative 2, as verified via western blotting. These findings suggest that derivative 2 can be a lead therapeutic compound for ALI, with GSK3β emerging as a promising novel target for the development of specific anti-ALI drugs.

Matrix metalloproteinases mediate influenza A-associated shedding of the alveolar epithelial glycocalyx.

The alveolar epithelium is protected by a heparan sulfate-rich, glycosaminoglycan layer called the epithelial glycocalyx. It is cleaved in patients with acute respiratory distress syndrome (ARDS) and in murine models of influenza A (IAV) infection, shedding fragments into the airspace from the cell surface. Glycocalyx shedding results in increased permeability of the alveolar-capillary barrier, amplifying acute lung injury. The mechanisms underlying alveolar epithelial glycocalyx shedding in IAV infection are unknown. We hypothesized that induction of host sheddases such as matrix metalloproteinases (MMPs) during IAV infection results in glycocalyx shedding and increased lung injury. We measured glycocalyx shedding and lung injury during IAV infection with and without treatment with the pan-MMP inhibitor Ilomastat (ILO) and in an MMP-7 knock out (MMP-7KO) mouse. C57BL/6 or MMP-7KO male and female mice were given IAV A/PR/8/34 (H1N1) at 30,000 PFU/mouse or PBS intratracheally. For some experiments, C56BL/6 mice were infected in the presence of ILO (100mg/kg) or vehicle given daily by IP injection. Bronchoalveolar lavage (BAL) and lung tissue were collected on day 1, 3, and 7 for analysis of glycocalyx shedding (BAL Syndecan-1) and lung injury (histology, BAL protein, BAL cytokines, BAL immune cell infiltrates, BAL RAGE). Expression and localization of the sheddase MMP-7 and its inhibitor TIMP-1 was examined by RNAScope. For in vitro experiments, MLE-12 mouse lung epithelial cells were cultured and treated with active or heat-inactivated heparinase (2.5 U/mL) prior to infection with IAV (MOI 1) and viral load and MMP-7 and TIMP-1 expression analyzed. IAV infection caused shedding of the epithelial glycocalyx into the BAL. Inhibition of MMPs with ILO reduced glycocalyx shedding by 36% (p = 0.0051) and reduced lung epithelial injury by 40% (p = 0.0404). ILO also reduced viral load by 68% (p = 0.027), despite having no significant effect on lung cytokine production. Both MMP-7 and its inhibitor TIMP-1 were upregulated in IAV infected mice: MMP-7 colocalized with IAV, while TIMP-1 was limited to cells adjacent to infection. However, MMP-7KO mice had similar glycocalyx shedding, epithelial injury, and viral load compared to WT littermates, suggesting redundancy in MMP sheddase function in the lung. In vitro, heparinase treatment before infection led to a 52% increase in viral load (p = 0.0038) without altering MMP-7 or TIMP-1 protein levels. Glycocalyx shedding and MMPs play key roles in IAV-induced epithelial injury, with significant impact on IAV viral load. Further studies are needed to understand which specific MMPs regulate lung epithelial glycocalyx shedding.

The influence of sex, age, and body height on the pulmonary vascular permeability index – a prospective observational study

The pulmonary vascular permeability index (PVPI) is a quotient of the extravascular lung water (EVLW) and the pulmonary blood volume (PBV). In acute respiratory distress syndrome (ARDS), the alveolar-capillary membrane integrity is disrupted. The result is a disproportionate increase of EVLW compared to the PBV and, hence, an increase in PVPI. Thus, PVPI has repetitively been discussed to extend the definition of ARDS. Besides sex, the influence of other anthropometric variables on PVPI has not been studied so far. However, since it is known that EVLW depends on body height and sex, we hypothesize that PVPI depends on anthropometric variables as well. This prospective single-center observational study included 1533 TPTD measurements of 251 non-critically ill patients (50.6% men) undergoing elective neuro-, thoracic, or abdominal surgery at the Munich Clinic Bogenhausen of the Technical University of Munich. Multivariate regressions were used to measure the influence of sex, age, and body height on PVPI. In all patients, PVPI was significantly higher in women (P < 0.001), with 34.4% having a PVPI > 2 compared to 15.9% of men. Mean PVPI significantly decreased with height (P < 0.001) and age (P < 0.001). Multivariate regressions allowed the calculation of mean reference surfaces. The 95th percentile surface for PVPI was > 3 for small and young women and well above 2 for all but tall and elderly men. In patients who underwent (lung reduction) thoracic surgery, the PVPI before and after surgery did not differ significantly (P = 0.531), and post-surgical PVPI did not correlate with the amount of lung resected (P = 0.536). Hence, we conclude that PVPI may be independent of the extent of lung volume reduction. However, PVPI is heavily dependent on sex, age, and body height. Anthropometric variables thus have a significant impact on the likelihood of misclassified abnormal PVPI. This warrants further studies since an increased PVPI, e.g. in the context of an ARDS, may be overlooked if anthropometric variables are not considered. We suggest reference surfaces based on the 95th-percentile corrected for sex, age, and height as a novel approach to normalize PVPI.

Imaging of ventilation and lung injury with low-frequency tomographic ultrasound.

Mechanical ventilation in the intensive care unit (ICU) is a life-saving technique for patients with acute respiratory failure, but is also associated with a high incidence of complications in the injured lung. Currently, there is no widely used monitoring technique to guide the ventilator setting to facilitate a precision medicine approach or to provide a real-time alert for developing adverse pulmonary conditions. Conventional ultrasound has been used as a thoracic bedside technology, but the lack of signal penetration into lung tissue results in images that often contain more information in their artifacts than in the images themselves. Perhaps the greatest obstacle to using traditional ultrasound in the ICU is the need for highly skilled technicians to perform the data collection. In contrast, low-frequency ultrasound (50-500 kHz) has been shown to penetrate the lung, and can detect air trapping in patients with chronic obstructive pulmonary disease (COPD). Here, we present a method of collecting low-frequency ultrasound computed tomographic (USCT) data in vivo on a mechanically ventilated porcine model and computing tomographic reconstructions of airflow during tidal breathing and induced lung injuries. We evaluate the ability of the novel low-frequency USCT system to image regional changes in sound speed in the thorax due to changes in airflow during tidal breathing and induced lung injuries. This represents the first study of low-frequency tomographic ultrasound imaging in vivo and the first to produce tomographic images of ventilatory changes invivo. USCT and computed tomography (CT) scan data were collected alternately on a mechanically ventilated Landrace pig weighing approximately 75 kg during tidal breathing, induced pneumothorax, atelectasis, and pleural effusion. The pneumothorax was induced by injecting air through a 5 mm thick intrathoracic tube inserted in the 8th posterior intercostal space. After removing the air, atelectasis was induced by ventilating the animal with a high concentration of oxygen and low tidal volumes. The pleural effusion was induced by injecting a saline solution through the tube. The USCT data were collected at 125 kHz using the USCT low-frequency ultrasound tomography (LUFT) system on a transducer belt placed around the animal's thorax. Tomographic reconstructions were computed from the USCT data using a regularized refraction-corrected Gauss-Newton-based time-of-flight reconstructionalgorithm. Cyclic changes in computed lung area during tidal breathing were demonstrated to agree with the respiratory rate on the mechanical ventilator. Reconstructed images computed at time steps during the procedure demonstrate regional changes consistent with what would be expected during the induced lung injury. No ground truth was available for images during the procedures since CT scans could only be taken before and after each established lunginjury. In this work, we have demonstrated in the first in vivo study using a mechanically ventilated porcine animal model that low-frequency ultrasound tomography has the ability to image regional changes in sound speed in the thorax corresponding to changes in airflow during tidal breathing and induced lung injury. The results show promise for using low-frequency USCT as a bedside imaging technique in the future for patients with acute respiratory distresssyndrome.

Nonreducing Sugar Scaffold Enables the Development of Immunomodulatory TLR4-specific LPS Mimetics with Picomolar Potency.

Innate immune defense mechanisms against infection and cancer encompass the modulation of pattern recognition receptor (PRR)-mediated inflammation, including upregulation of various transcription factors and the activation of pro-inflammatory pathways important for immune surveillance. Dysfunction of PRRs-mediated signaling has been implicated in cancer and autoimmune diseases, while the overactivation of PRRs-driven responses during infection can lead to devastating consequences such as acute lung injury or sepsis. We used crystal structure-based design to develop immunomodulatory lipopolysaccharide (LPS) mimetics targeting one of the ubiquitous PRRs, Toll-like Receptor 4 (TLR4). Taking advantage of an exo-anomeric conformation and specific molecular shape of synthetic nonreducing β,β-diglucosamine, which was investigated by NMR, we developed two sets of lipid A mimicking glycolipids capable of either potently activating innate immune responses or inhibiting pro-inflammatory signaling. Stereoselective 1,1'-glycosylation towards fully orthogonally protected nonreducing GlcNβ(1↔1')βGlcN followed by stepwise assembly of differently functionalised phosphorylated glycolipids provided biologically active molecules that were evaluated for their ability to trigger or to inhibit cellular innate immune responses. Two LPS mimetics, identified as potent TLR4-specific inducers of the intracellular signaling pathways, serve as vaccine adjuvant- and immunotherapy candidates, while anionic glycolipids with TLR4-inhibitory potential hold therapeutic promise for the management of acute or chronic inflammation.

Impact of airway closure and lung collapse on inhaled nitric oxide effect in acute lung injury: an experimental study

BackgroundEfficacy of inhaled therapy such as Nitric Oxide (iNO) during mechanical ventilation may depend on airway patency. We hypothesized that airway closure and lung collapse, countered by positive end-expiratory pressure (PEEP), influence iNO efficacy. This could support the role of an adequate PEEP titration for inhalation therapy. The main aim of this study was to assess the effect of iNO with PEEP set above or below the airway opening pressure (AOP) generated by airway closure, on hemodynamics and gas exchange in swine models of acute respiratory distress syndrome. Fourteen pigs randomly underwent either bilateral or asymmetrical two-hit model of lung injury. Airway closure and lung collapse were measured with electrical impedance tomography as well as ventilation/perfusion ratio (V/Q). After AOP detection, the effect of iNO (10ppm) was studied with PEEP set randomly above or below regional AOP. Respiratory mechanics, hemodynamics, and gas-exchange were recorded.ResultsAll pigs presented airway closure (AOP > 0.5cmH2O) after injury. In bilateral injury, iNO was associated with an improved mean pulmonary pressure from 49 ± 8 to 42 ± 7mmHg; (p = 0.003), and ventilation/perfusion matching, caused by a reduction in pixels with low V/Q and shunt from 16%[IQR:13–19] to 9%[IQR:4–12] (p = 0.03) only at PEEP set above AOP. iNO had no effect on hemodynamics or gas exchange for PEEP below AOP (low V/Q 25%[IQR:16–30] to 23%[IQR:14–27]; p = 0.68). In asymmetrical injury, iNO improved pulmonary hemodynamics and ventilation/perfusion matching independently from the PEEP set. iNO was associated with improved oxygenation in all cases.ConclusionsIn an animal model of bilateral lung injury, PEEP level relative to AOP markedly influences iNO efficacy on pulmonary hemodynamics and ventilation/perfusion match, independently of oxygenation.

Veno-venous extracorporeal membrane oxygenation in devastating bacterial pneumonia: a case report and review of the literature

BackgroundBacterial pneumonia is one of the most common causes of acute respiratory distress syndrome. In fulminant cases, when mechanical ventilation fails, veno-venous extracorporeal membrane oxygenation is required. However, this method is still associated with significant mortality and a wide range of potential complications. However, there are now many case reports of good outcomes even in patients with prolonged extracorporeal oxygenation, as in our rather complicated case report.Case presentationOur case report describes a complicated but successful treatment of a severe, devastating bacterial pneumonia in a 39-year-old European polymorbid woman with a rare form of diabetes mellitus, which had been poorly compensated for a long time with limited compliance, in the context of a combined immunodeficiency that strongly influenced the course of the disease. The patient’s hospitalization required a total of 30 days of veno-venous extracorporeal membrane oxygenation therapy and more than 50 days of mechanical ventilation. Numerous complications, particularly bleeding, required seven chest drains, two extracorporeal membrane oxygenation circuit changes, and one surgical revision. The patient’s mental state required repeated psychiatric intervention.ConclusionIt is possible that even the initially severely damaged lung parenchyma can develop its regenerative potential if suitable conditions are provided for this process, including a sufficiently long period of extracorporeal membrane oxygenation.We believe that this case report may also contribute to the consideration of the indications and contraindications of extracorporeal support. The authors also discuss the limitations and risks of prolonged veno-venous extracorporeal membrane oxygenation support and periprocedural anticoagulation strategies.

Intratracheal delivery of macrophage targeted Celastrol-loaded PLGA nanoparticles for enhanced anti-inflammatory efficacy in acute lung injury mice

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are common causes of respiratory failure in critically ill patients. There is still a lack of definitive and effective treatment options, and the mortality rate remains as high as 30% to 40%. Effective therapeutics for ALI/ARDS are greatly hindered by the side effects resulting from inefficient delivery to the disease lesions and off-targeting biodistribution of drugs. Macrophages play an integral role in maintaining the steady state of the immune system and are involved in inflammation processes. Thus, nanodrug to accurately target macrophages have the potential to transform disease treatment. Here, we developed an mannosylated drug delivery system to target and deliver celastrol (Cel) to the alveolar macrophages for enhanced alleviating the cytokines in LPS-induce ALI mice. In vitro data demonstrated that the as-synthesized Man@Cel-NPs significantly improved the targeting of Cel into the inflammatory macrophages via mannose receptor-mediated phagocytosis. In vivo experiments further showed that intratracheal delivery of Man@Cel-NPs can improve the dysregulation of inflammatory response in LPS-induced mice by inhibiting the release of inflammatory cytokines and increasing autophagy and decreasing apoptosis in lungs. This work provides a potential NP platform for the locally tracheal delivery of herbal ingredients and exhibits promising clinical potential in the treatment of numerous respiratory diseases, including ALI/ARDS.

The Effects of the Pneumonia Lung Microenvironment on MSC Function.

Despite promise in preclinical models of acute respiratory distress syndrome (ARDS), mesenchymal stem cells (MSC) have failed to translate to therapeutic benefit in clinical trials. The MSC is a live cell medicine and interacts with the patient's disease state. Here, we explored this interaction, seeking to devise strategies to enhance MSC therapeutic function. Human bone-marrow-derived MSCs were exposed to lung homogenate from healthy and E. coli-induced ARDS rat models. Apoptosis and functional assays of the MSCs were performed. The ARDS model showed reduced arterial oxygenation, decreased lung compliance and an inflammatory microenvironment compared to controls. MSCs underwent more apoptosis after stimulation by lung homogenate from controls compared to E. coli, which may explain why MSCs persist longer in ARDS subjects after administration. Changes in expression of cell surface markers and cytokines were associated with lung homogenate from different groups. The anti-microbial effects of MSCs did not change with the stimulation. Moreover, the conditioned media from lung-homogenate-stimulated MSCs inhibited T-cell proliferation. These findings suggest that the ARDS microenvironment plays an important role in the MSC's therapeutic mechanism of action, and changes can inform strategies to modulate MSC-based cell therapy for ARDS.

Role and Mechanism of Sialic Acid in Alleviating Acute Lung Injury through In Vivo and In Vitro Models.

Excessive inflammatory reactions are the most important pathological injury factor in acute lung injury (ALI). Our recent study found that sialic acid had an anti-colitis effect. In this study, the effect of sialic acid (SA) on acute lung inflammation was investigated. A lipopolysaccharide (LPS)-induced ALI animal model and LPS-stimulated HUVEC cell model were used to evaluate the anti-inflammatory effect of SA and study its molecular mechanisms. Compared with the LPS group, the lung index of the SA group decreased from 0.79 ± 0.05% to 0.58 ± 0.06% (LPS + 50 SA) and 0.62 ± 0.02% (LPS + 100 SA), with p < 0.01, suggesting that SA could improve the pulmonary edema of mice and alleviate LPS-induced lung injury. Transcriptome research identified 26 upregulated genes and 25 downregulated genes involved in the protection of SA against ALI. These genes are mainly related to the MAPK and NF-κB signaling pathways. Our study also proved that SA markedly downregulated the expression of inflammatory factors and blocked the JNK/p38/PPAR-γ/NF-κB pathway. Meanwhile, SA treatment also upregulated the expression of HO-1 and NQO1 in ALI mice. In vitro, SA obviously repressed the expressions of inflammatory cytokines and the JNK/p38-NF-κB/AP-1 pathway. SA also regulated the expression of oxidative stress-related genes through the Nrf2 pathway. Taken together, SA exhibits a protective role by modulating the anti-inflammatory and anti-oxidation pathways in ALI, and it may be a promising candidate for functional foods to prevent ALI.

One case of comprehensive treatment of acute severe ammonia-induced intoxication with extracorporeal membrane oxygenation

Acute ammonia-induced intoxication is a kind of acute irritant gas poisoning, which mainly causes systemic inflammatory reaction and immune dysfunction through direct and indirect lung injury, leading to chemogenic pulmonary edema and acute respiratory distress syndrome (ARDS). The mechanism of its toxic injury is complex, and the fatality rate of patients increases significantly once ARDS occurs. In this paper, the patient with acute and severe ammonia-induced intoxication was successfully treated by extracorporeal membrane oxygenation (ECMO) combined with fiberoptic bronchoscopy and other critical technologies, and achieved good results. By analyzing the diagnosis and treatment process of severe ammonia-induced intoxication complicated with ARDS patients, this paper summarizes the clinical characteristics of ammonia-induced intoxication injury, and the application opportunities of ECMO and various critical medical technologies, so as to facilitate the efficient intervention and treatment of ammonia-induced intoxication according to the clinical opportunity and improve the survival rate of patients.

MicroRNA-451 from Human Umbilical Cord-Derived Mesenchymal Stem Cell Exosomes Inhibits Alveolar Macrophage Autophagy via Tuberous Sclerosis Complex 1/Mammalian Target of Rapamycin Pathway to Attenuate Burn-Induced Acute Lung Injury in Rats.

Our previous studies established that microRNA (miR)-451 from human umbilical cord mesenchymal stem cell-derived exosomes (hUC-MSC-Exos) alleviates acute lung injury (ALI). This study aims to elucidate the mechanisms by which miR-451 in hUC-MSC-Exos reduces ALI by modulating macrophage autophagy. Exosomes were isolated from hUC-MSCs. Severe burn-induced ALI rat models were treated with hUC-MSC-Exos carrying the miR-451 inhibitor. Hematoxylin-eosin staining evaluated inflammatory injury. Enzyme-linked immunosorbnent assay measured lipopolysaccharide (LPS), tumor necrosis factor-α, and interleukin-1β levels. qRT-PCR detected miR-451 and tuberous sclerosis complex 1 (TSC1) expressions. The regulatory role of miR-451 on TSC1 was determined using a dual-luciferase reporter system. Western blotting determined TSC1 and proteins related to the mammalian target of rapamycin (mTOR) pathway and autophagy. Immunofluorescence analysis was conducted to examine exosomes phagocytosis in alveolar macrophages and autophagy level. hUC-MSC-Exos with miR-451 inhibitor reduced burn-induced ALI and promoted macrophage autophagy. MiR-451 could be transferred from hUC-MSCs to alveolar macrophages via exosomes and directly targeted TSC1. Inhibiting miR-451 in hUC-MSC-Exos elevated TSC1 expression and inactivated the mTOR pathway in alveolar macrophages. Silencing TSC1 activated mTOR signaling and inhibited autophagy, while TSC1 knockdown reversed the autophagy from the miR-451 inhibitor-induced. miR-451 from hUC-MSC exosomes improves ALI by suppressing alveolar macrophage autophagy through modulation of the TSC1/mTOR pathway, providing a potential therapeutic strategy for ALI.

Araloside A alleviates sepsis-induced acute lung injury via PHD2/HIF-1α in macrophages

BackgroundAcute lung injury (ALI)-induced acute respiratory syndromes is a critical pathological sequala of sepsis. Araloside A (ARA), extracted from Aralia taibaiensis, possesses anti-oxidative and pro-apoptotic effects, as well as a protective effect against inflammatory diseases such as gastric ulcers. However, its impact on progression of ALI remains unknown. This study seeks to assess the therapeutic effect of ARA in sepsis-induced ALI, and to elucidate the underlying mechanism. MethodsSepsis-induced ALI was induced in C57BL/6 mice using lipopolysaccharide (LPS) or cecal ligation and puncture (CLP) along with simultaneous administration of ARA. In vitro, bone marrow-derived macrophages (BMDMs) and RAW264.7 cells were exposed to LPS to activate proinflammatory macrophages in the presence/absence of ARA. RNA sequencing of BMDMs was then conducted to elucidate the detailed mechanism. ResultsTreatment of mice with ARA led to a significant reduction in serum level of inflammatory cytokines, ameliorated sepsis-induced ALI (i.e., impaired barrier integrity, cell apoptosis), and increased survival of septic mice. In vitro, ARA effectively inhibited activation of proinflammatory BMDMs. In addition, RNA sequencing revealed that the PHD2/HIF-1α signaling played a critical role in the anti-inflammatory effects of ARA. ARA suppressed proinflammatory macrophages to ameliorate lung inflammation in septic mice by restoring PHD2/HIF-1α signaling. ConclusionsARA prevented mice from the fatal effects of sepsis by restoring PHD2/HIF-1α signaling, thereby inhibiting activation of proinflammatory macrophages. These findings suggest that ARA could be a promising therapy for sepsis-induced ALI.

RAMP1 Signaling Mitigates Acute Lung Injury by Distinctively Regulating Alveolar and Monocyte-Derived Macrophages.

Acute respiratory distress syndrome (ARDS) is a life-threatening lung injury that induces cytokine hypersecretion. Receptor activity-modifying protein (RAMP) 1, a subunit of the calcitonin gene-related peptide (CGRP) receptor, regulates the production of cytokines. This study examined the role of RAMP1 signaling during lipopolysaccharide (LPS)-induced acute lung injury (ALI). LPS administration to wild-type (WT) mice depleted alveolar macrophages (AMs) and recruited monocyte-derived macrophages (MDMs) and neutrophils. RAMP1-deficient (RAMP1-/-) mice exhibited higher lung injury scores, cytokine levels, and cytokine-producing neutrophil infiltration. RAMP1-deficient AMs produced more cytokines in response to LPS than WT AMs. Adoptive transfer of RAMP1-deficient AMs to RAMP1-/- mice increased cytokine levels and neutrophil accumulation compared to the transfer of WT AMs. RAMP1-/- mice had reduced MDM recruitment and lower pro-inflammatory and reparative macrophage profiles. Cultured bone marrow (BM)-derived RAMP1-deficient macrophages stimulated with LPS showed decreased expression of pro-inflammatory and pro-repairing genes. CGRP administration to WT mice reduced cytokine production and neutrophil accumulation. These findings indicate that RAMP1 signaling mitigates LPS-induced ALI by inactivating AMs and promoting inflammatory and repair activities of MDMs. Targeting RAMP1 signaling presents a potential therapeutic approach for the treatment of ARDS.

Nebulized Lipopolysaccharide Causes Delayed Cortical Neuroinflammation in a Murine Model of Acute Lung Injury.

Lung injury caused by respiratory infection is a major cause of hospitalization and mortality and a leading origin of sepsis. Sepsis-associated encephalopathy and delirium are frequent complications in patients with severe lung injury, yet the pathogenetic mechanisms remain unclear. Here, 70 female C57BL/6 mice were subjected to a single full-body-exposure with nebulized lipopolysaccharide (LPS). Neuromotor impairment was assessed repeatedly and brain, blood, and lung samples were analyzed at survival points of 24 h, 48 h, 72 h, and 96 h after exposure. qRT-PCR revealed increased mRNA-expression of TNFα and IL-1β 24 h and 48 h after LPS-exposure in the lung, concomitantly with increased amounts of proteins in bronchoalveolar lavage and interstitial lung edema. In the cerebral cortex, at 72 h and/or 96 h after LPS exposure, the inflammation- and activity-associated markers TLR4, GFAP, Gadd45b, c-Fos, and Arc were increased. Therefore, single exposure to nebulized LPS not only triggers an early inflammatory reaction in the lung but also induces a delayed neuroinflammatory response. The identified mechanisms provide new insights into the pathogenesis of sepsis-associated encephalopathy and might serve as targets for future therapeutic approaches.

Human placental mesenchymal stem cells transplantation repairs the alveolar epithelial barrier to alleviate lipopolysaccharides-induced acute lung injury

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are accompanied by high mortality rates and few effective treatments. Transplantation of human placental mesenchymal stem cells (hPMSCs) may attenuate ALI and the mechanism is still unclear. Our study aimed to elucidate the potential protective effect and therapeutic mechanism of hPMSCs against lipopolysaccharide (LPS)-induced ALI, An ALI model was induced by tracheal instillation of LPS into wild-type (WT) and angiotensin-converting enzyme 2 (ACE2) knockout (KO) male mice, followed by injection of hPMSCs by tail vein. Treatment with hPMSCs improved pulmonary histopathological injury, reduced pulmonary injury scores, decreased leukocyte count and protein levels in bronchoalveolar lavage fluid(BALF), protected the damaged alveolar epithelial barrier, and reversed LPS-induced upregulation of pro-inflammatory factors Interleukin-6 (IL-6) and Tumor necrosis factor-α(TNF-α) and downregulation of anti-inflammatory factor Interleukin-6(IL-10) in BALF. Moreover, administration of hPMSCs inhibited Angiotensin (Ang)II activation and promoted the expression levels of ACE2 and Ang (1–7) in ALI mice. Pathological damage, inflammation levels, and disruption of alveolar epithelial barrier in ALI mice were elevated after the deletion of ACE2 gene, and the Renin angiotensin system (RAS) imbalance was exacerbated. The therapeutic effect of hPMSCs was significantly reduced in ACE2 KO mice. Our findings suggest that ACE2 plays a key role in hPMSCs repairing the alveolar epithelial barrier to protect against ALI, laying a new foundation for the clinical treatment of ALI.

Aerosol of Enoximone/Hydroxypropyl-β-Cyclodextrin Inclusion Complex, Biopharmaceutical Evidence for ARDS Applicability.

Phosphodiesterase (PDE) inhibitors are gaining interest in the context of pulmonary pathologies. In particular, the PDE3 inhibitor enoximone (ENXM) has shown potential relative to the cure of asthma, chronic obstructive pulmonary disease (COPD), and acute respiratory distress syndrome (ARDS). Despite its administration via inhalation being planned for use against COVID-19 related ARDS (C-ARDS), presently, no inhalable medicine containing ENXM is available. This study aims to develop a new formulation suitable for pulmonary administration of ENXM. A solution for nebulization, based on the complex between ENXM and Hydroxypropyl-β-Cyclodextrin (HPβCD) (ENXM/HPβCD) is developed. The obtained solution is characterized in terms of aerodynamic distributions and biopharmaceutical features. The evaluation of the aerosol droplets indicates a good bronchi-lung distribution of the drug. Biological evaluations of the air-liquid interface (ALI) in an in vitro lung cell model demonstrates that ENXM/HPβCD is capable of a local direct effect, increasing intracellular cyclic adenosine monophosphate (cAMP) levels and protecting from oxidative stress. This study offers a promising advance in the optimization of enoximone delivery to the lungs.

GWAS and polygenic risk score of severe COVID-19 in Eastern Europe.

COVID-19 disease has infected more than 772 million people, leading to 7 million deaths. Although the severe course of COVID-19 can be prevented using appropriate treatments, effective interventions require a thorough research of the genetic factors involved in its pathogenesis. We conducted a genome-wide association study (GWAS) on 7,124 individuals (comprising 6,400 controls who had mild to moderate COVID-19 and 724 cases with severe COVID-19). The inclusion criteria were acute respiratory distress syndrome (ARDS), acute respiratory failure (ARF) requiring respiratory support, or CT scans indicative of severe COVID-19 infection without any competing diseases. We also developed a polygenic risk score (PRS) model to identify individuals at high risk. We identified two genome-wide significant loci (P-value <5 × 10-8) and one locus with approximately genome-wide significance (P-value = 5.92 × 10-8-6.15 × 10-8). The most genome-wide significant variants were located in the leucine zipper transcription factor like 1 (LZTFL1) gene, which has been highlighted in several previous GWAS studies. Our PRS model results indicated that individuals in the top 10% group of the PRS had twice the risk of severe course of the disease compared to those at median risk [odds ratio = 2.18 (1.66, 2.86), P-value = 8.9 × 10-9]. We conducted one of the largest studies to date on the genetics of severe COVID-19 in an Eastern European cohort. Our results are consistent with previous research and will guide further epidemiologic studies on host genetics, as well as for the development of targeted treatments.

Prospects of Natural Polymers based Nano-drug Delivery Systems in the Treatment of Pulmonary Disorders

Numerous lung conditions, including lung cancer, influenza, acute respiratory distress syndrome, chronic obstructive pulmonary disease [COPD], asthma, and pneumonia, present a great threat to people all over the world. A range of pharmaceutical drugs, peptides, antibodies, and genetic therapies have all been used to treat chronic lung illnesses. Unfortunately, the majority of chronic lung disorders cannot be fully cured by medication alone. At the moment, managing the symptoms is the only asthma treatment. This article provides a brief overview of the state-of-the-art understanding of the function of natural polymeric materials and emphasises recent developments in innovative drug delivery systems that may help treat a variety of lung diseases. Furthermore, the paper also discusses the latest application of natural polymeric materials for targeting gene delivery through different approaches.

Blockade of the CCR3 receptor reduces neutrophil recruitment to the lung during acute inflammation

Abstract Neutrophils represent one of the host's first lines of defense against invading pathogens. However, an aberrant activation can cause damage to the host. In the case of respiratory infections with viral or bacterial pathogens, one of the most common complications is the development of acute respiratory distress syndrome (ARDS), in which neutrophil infiltration into the lung is a hallmark. Neutrophils gain expression of chemokine receptors under inflammatory conditions, and their activation can amplify the neutrophil responses. Earlier studies showed that neutrophils recruited to the lung mucosa during bacterial infection upregulate expression of CCR3 and ex vivo stimulation of CCR3 results in an increased neutrophil activation. Therefore, the modulation of effector functions or migration of neutrophils to target sites through chemokine receptors constitutes an opportunity for pharmacological intervention. We aimed to determine whether the blockade of the CCR3 using the specific antagonist SB-328437 reduces neutrophil recruitment and inflammation in the lung in the LPS-induced lung injury model and influenza infection in mice. We found that neutrophils acquire CCR3 expression in the lung alveolar space. The intraperitoneal administration of SB-328437 reduced neutrophil recruitment to the lung alveolar space and reduced tissue damage in both the LPS-induced lung injury model and influenza infection. Moreover, treatment with SB-328437 reduced the percentage of neutrophils producing TNFα and neutrophil activation in the alveolar space. Together, these data suggest that CCR3 blockade might be a pharmacological strategy to prevent the aberrant neutrophil activation that results detrimental for the host but preserves sufficient effector response to control the pathogen.