Interleukin 8 and acute lung injury

Elk1 enhances inflammatory cell infiltration and exacerbates acute lung injury/acute respiratory distress syndrome by suppressing Fcgr2b transcription

OBJECTIVE

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are associated with significant mortality rates. The role of Fcgr2b in the pathogenesis of ALI/ARDS is not fully elucidated. This study aimed to investigate the functions of Fcgr2b in ALI/ARDS and explore its underlying mechanisms.

METHODS

Methods: In this study, rat models of ARDS and pulmonary microvascular endothelial cell (PMVEC) injury models were established through the administration of lipopolysaccharide (LPS). The expression levels of Fcgr2b and Elk1 were quantified in both LPS-induced ARDS rats and PMVECs. Subsequent gain- and loss-of-function experiments were conducted, followed by comprehensive assessments of lung tissue for pathomorphological changes, edema, glycogen storage, fibrosis, and infiltration of inflammatory cells. Additionally, bronchoalveolar lavage fluid was analyzed for T-helper 17 (Th17) cell infiltration, inflammatory response, and microvascular permeability to evaluate lung injury severity in ARDS models. Furthermore, the activity, cytotoxicity, apoptosis, and angiogenic potential of PMVECs were assessed to gauge cell injury. The interaction between Elk1 and Fcgr2b was also examined to confirm their regulatory relationship.

RESULTS

In the context of LPS-induced ARDS and PMVEC injury, Fcgr2b expression was markedly reduced, whereas Elk1 expression was elevated. Overexpression of Fcgr2b led to a decrease in Th17 cell infiltration and mitigated lung tissue damage in ARDS models, in addition to reducing LPS-induced injury in PMVECs. Elk1 was found to suppress Fcgr2b transcription through the recruitment of histone 3 lysine 9 trimethylation (H3K9me3). Knockdown of Elk1 diminished Th17 cell infiltration and lung tissue damage in ARDS models, and alleviated LPS-induced injury in PMVECs, effects that were reversed upon Fcgr2b upregulation.

CONCLUSION

Elk1 negatively regulates Fcgr2b transcription, thereby augmenting the inflammatory response and exacerbating lung injury in LPS-induced ALI/ARDS.

Micromorphological features and interleukin 6, 8, and 18 expressions in post-mortem lung tissue in cases with acute respiratory distress syndrome

The purpose of this study was to analyze the presence of interleukins 6, 8, and 18 in post-mortem lung tissue of subjects deceased due to polytrauma. In addition to this, we have described different micromorphological features of lung tissue in ARDS cases associated with fatal traffic trauma. A total of 18 autopsy cases with ARDS after polytrauma and 15 control autopsy cases were analyzed in this study. From every subject, we collected one sample for each lung lobe. All of the histological sections were analyzed by using light microscopy, and for the purpose of ultrastructural analysis, we used transmission electron microscopy. Representative sections were further processed by way of immunohistochemistry analysis. Quantification of IL-6, IL-8, and IL-18-positive cells was conducted by applying the IHC score. We noticed that all samples of ARDS cases exhibited elements of the proliferative phase. Immunohistochemical analysis of lung tissue in patients with ARDS showed strong positive staining for IL-6 (2.8 ± 0.7), IL-8 (2.2 ± 1.3), and IL-18 (2.7 ± 1.2), while staining of the control samples resulted in no positivity to low/moderate positivity (for IL-6 1.4 ± 0.5; for IL-8 0.1 ± 0.4; for IL-18 0.6 ± 0.9). Only IL-6 correlated negatively with the patients' age (r =  -0.6805, p < 0.01). In this study, we described microstructural changes in lung sections of ARDS cases and control cases, as well as interleukins' expression, demonstrating that autopsy material is as informing as tissue samples collected by performing open lung biopsy.

Function and inhibition of P38 MAP kinase signaling: Targeting multiple inflammation diseases

Inflammation is a natural host defense mechanism that protects the body from pathogenic microorganisms. A growing body of research suggests that inflammation is a key factor in triggering other diseases (lung injury, rheumatoid arthritis, etc.). However, there is no consensus on the complex mechanism of inflammatory response, which may include enzyme activation, mediator release, and tissue repair. In recent years, p38 MAPK, a member of the MAPKs family, has attracted much attention as a central target for the treatment of inflammatory diseases. However, many p38 MAPK inhibitors attempting to obtain marketing approval have failed at the clinical trial stage due to selectivity and/or toxicity issues. In this paper, we discuss the mechanism of p38 MAPK in regulating inflammatory response and its key role in major inflammatory diseases and summarize the synthetic or natural products targeting p38 MAPK to improve the inflammatory response in the last five years, which will provide ideas for the development of novel clinical anti-inflammatory drugs based on p38 MAPK inhibitors.

RNA-Seq profiling of circular RNAs in mice with lipopolysaccharide-induced acute lung injury

Acute lung injury (ALI) is a serious illness that develops suddenly, progresses rapidly, has a poor treatment response and a high mortality rate. Studies have found that circular RNAs (circRNA) play a critical role in several diseases, but their role in ALI remains unclear. The aim of this study was to identify circRNAs that are associated with ALI and investigate their potential molecular mechanisms. A comparison of lung circRNA and microRNA expression profiles in mice with ALI and controls was performed by RNA-sequencing. A bioinformatic analysis was conducted to identify differentially expressed (DE) RNAs, to construct competitive endogenous RNA (ceRNA) networks, and to analyze their function and pathways. Then, a protein-protein interaction (PPI) network was generated by the Search Tool for the Retrieval of Interacting Genes database, and hub genes were identified using Cytoscape. Furthermore, a key ceRNA subnetwork was constructed based on these hub genes. Overall, we found 239 DE circRNAs and 42 DE microRNAs in ALI mice compared to controls. Additionally, the molecular mechanism of ALI was further understood by building ceRNA networks based on these DE genes. ALI-induced circRNAs are mostly function in the inflammatory response and metabolic processes. Moreover, DE circRNAs are primarily involved in the nuclear factor (NF)-kappa B and PI3K-Akt signaling pathways. Seven hub genes were derived from the PPI network of 191 genes, followed by the construction of circRNA-miRNA-hub gene subnetworks. In this study, circRNA profiles are remarkably changed in mice with LPS-triggered ALI, and their potential contribution to the disease is revealed.

Anti-inflammatory effect and component analysis of Chaihu Qingwen granules

ETHNOPHARMACOLOGICAL RELEVANCE

As prevalent acute respiratory condition in clinical practice, acute lung injury has a quick start and severe symptoms which can harm patients physically. Chaihu Qingwen granules (CHQW) is a classic formula for the treatment of respiratory diseases. Clinical observation shows that CHQW has good efficacy in treating colds, coughs, and fevers.

AIM OF THE STUDY

The aim of this study was to investigate the anti-inflammatory effect of CHQW on lipopolysaccharide (LPS)-induced acute lung injury (ALI) model in rats and to explore its potential mechanism, as well as to clarify its substance composition.

MATERIALS AND METHODS

Male SD rats were randomly divided into the blank group, the model group, the ibuprofen group, the Lianhua Qingwen capsule group and the CHQW group (2, 4 and 8 g/kg, respectively). The LPS-induced acute lung injury (ALI) model in rats was established after pre-administration. The histopathological changes in the lung and the levels of inflammatory factors in bronchoalveolar lavage fluid (BALF) and serum of ALI rats were observed. The inflammation-related proteins toll-like receptor 4 (TLR4), inhibitory kappa B alpha (IκBα), phospho-IκBα (p-IκBα), nuclear-factor-kappa B (NF-κB), and NLR family pyrin domain containing 3(NLRP3) expression levels were measured by western blotting analysis and immunohistochemical analysis. The chemical composition of CHQW was identified by liquid chromatography-quadrupole-time of flight-mass spectrometry (LC-Q-TOF-MS).

RESULTS

CHQW significantly ameliorated lung tissue pathological injury in LPS-induced ALI rats and decreased the release of inflammatory cytokines (interleukin-1β, interleukin-17 and tumor necrosis factor-α) in BALF and serum. In addition, CHQW decreased the expression of TLR4, p-IκBα and NF-κB proteins, increased the level of IκBα, regulated the TLR4/NF-κB signaling pathway, and inhibited the activation of NLRP3. The chemical components of CHQW were analyzed by LC-Q-TOF-MS, and a total of 48 components were identified by combining information from the literature, mainly flavonoids, organic acids, lignans, iridoids and phenylethanoid glycosides.

CONCLUSION

The results of this study showed that the pretreatment of CHQW had a strong protective effect on LPS-induced ALI in rats, reducing lung tissue lesions and decreasing inflammatory cytokines released in BALF and serum. The protective mechanism of CHQW may be related to the inhibition of the TLR4/NF-κB signaling pathway and NLRP3 activation. The main active ingredients of CHQW are flavonoids, organic acids, lignans, iridoids and phenylethanoid glycosides.

Synthetic surfactant with a combined SP-B and SP-C analogue is efficient in rabbit models of adult and neonatal respiratory distress syndrome

Respiratory distress syndrome (RDS) in premature infants is caused by insufficient amounts of endogenous lung surfactant and is efficiently treated with replacement therapy using animal-derived surfactant preparations. On the other hand, adult/acute RDS (ARDS) occurs secondary to for example, sepsis, aspiration of gastric contents, and multitrauma and is caused by alveolar endothelial damage, leakage of plasma components into the airspaces and inhibition of surfactant activity. Instillation of surfactant preparations in ARDS has so far resulted in very limited treatment effects, partly due to inactivation of the delivered surfactants in the airspace. Here, we develop a combined surfactant protein B (SP-B) and SP-C peptide analogue (Combo) that can be efficiently expressed and purified from Escherichia coli without any solubility or purification tag. NMR spectroscopy shows that Combo peptide forms α-helices both in organic solvents and in lipid micelles, which coincide with the helical regions described for the isolated SP-B and SP-C parts. Artificial Combo surfactant composed of synthetic dipalmitoylphosphatidylcholine:palmitoyloleoylphosphatidylglycerol, 1:1, mixed with 3 weights % relative to total phospholipids of Combo peptide efficiently improves tidal volumes and lung gas volumes at end-expiration in a premature rabbit fetus model of RDS. Combo surfactant also improves oxygenation and respiratory parameters and lowers cytokine release in an acid instillation-induced ARDS adult rabbit model. Combo surfactant is markedly more resistant to inhibition by albumin and fibrinogen than a natural-derived surfactant in clinical use for the treatment of RDS. These features of Combo surfactant make it attractive for the development of novel therapies against human ARDS.

Protective effect of liriodendrin on IgG immune complex-induced acute lung injury via inhibiting SRC/STAT3/MAPK signaling pathway: a network pharmacology research

The primary objectives of this research were to investigate the protective effects of liriodendrin against IgG immune complex (IgG-IC)-induced acute lung injury (ALI) and to elucidate the underlying mechanisms. This study employed a mouse and cell model of IgG-IC-induced acute lung injury. Lung tissue was stained with hematoxylin-eosin to observe pathological alterations and arterial blood gas analysis was tested. Inflammatory cytokines, including interleukin-6 (IL-6), interleukin-1β (IL-1β), and tumor necrosis factor-alpha (TNF-α), were measured using ELISA. The mRNA expression of inflammatory cytokines was assessed via RT-qPCR. Molecular docking and enrichment analysis were combined to identify the most potential signaling pathways modulated by liriodendrin, which were then verified using western blot analysis in IgG-IC-induced ALI models. We identified 253 shared targets between liriodendrin and IgG-IC-induced acute lung injury from the database. Through network pharmacology, enrichment analysis, and molecular docking, SRC was determined to be the most closely associated target of liriodendrin in IgG-IC-induced ALI. Pretreatment with liriodendrin notably reduced the increased cytokine secretion of IL-1β, IL-6, and TNF-α. Histopathological analysis of lung tissue demonstrated a protective effect of liriodendrin on IgG-IC-induced acute lung injury in mice. Arterial blood gas analysis showed liriodendrin ameliorated acidosis and hypoxemia efficiently. Further studies revealed that liriodendrin pretreatment substantially attenuated the elevated phosphorylation levels of SRC's downstream components (JNK, P38, and STAT3), suggesting that liriodendrin may protect against IgG-IC-induced ALI via the SRC/STAT3/MAPK pathway. Our findings indicate that liriodendrin protects against IgG-IC-induced acute lung injury by inhibiting the SRC/STAT3/MAPK signaling pathway, suggesting that liriodendrin may serve as a potential treatment for acute lung injury caused by IgG-IC.

Silencing ApoC3 alleviates LPS-induced acute lung injury by inhibiting TLR signaling pathway

This study aims to confirm whether apolipoprotein C3 (ApoC3) can regulate the inflammatory response and tissue damage in acute lung injury (ALI) and explore its regulatory pathway. ALI mouse model was established by intraperitoneal injection of lipopolysaccharide (LPS). ApoC3 levels were detected by real-time quantitative polymerase chain reaction, immunohistochemistry, and western blot assays. The levels of various inflammatory factors were detected by enzyme-linked immunosorbent assay and western blot analysis. Finally, the expression of toll-like receptor (TLR)/nuclear factor kappa B (NF-κB) signaling pathway-related protein [TLR2, myeloid differentiation primary response protein 88 (MyD88), IL-1 receptor-associated kinase 1 (IRAK1), NF-κB p65, and inhibitor of kappa B alpha (IκBα)], SLP adaptor and CSK interacting membrane protein (SCIMP), spleen tyrosine kinase (Syk), and phosphorylated (p)-Syk was detected by western blot analysis. ApoC3 was overexpressed in ALI mouse lung tissue and cell inflammation model. Silencing ApoC3 reduced inflammatory factors and alleviated lung tissue damage in ALI mice. Silencing ApoC3 reduced inflammatory factors and downregulated the expression of TLR2, MyD88, IRAK1, NF-κB p65, and increased IκBα expression in LPS-treated RAW264.7 cells. Moreover, co-transfection of si-TLR2 and shApoC3 further enhanced the inhibitory effects on the levels of inflammatory factors induced by silencing ApoC3. ApoC3 overexpression increased the levels of inflammatory factors and protein expression of SCIMP and p-Syk, while silencing TLR2 reversed the promotive effects of ApoC3 overexpression on above factors. In LPS-induced ALI mouse model and inflammatory cell model, downregulation of ApoC3 reduced inflammatory factors and relieved tissue damage. This process might be achieved through the TLR pathway.

Shiwei Qingwen decoction regulates TLR4/NF-κB signaling pathway and NLRP3 inflammasome to reduce inflammatory response in lipopolysaccharide -induced acute lung injury

ETHNOPHARMACOLOGICAL RELEVANCE

Shiwei Qingwen decoction (SWQ), a Chinese herbal formula based on the classic traditional Chinese medicine prescription Yu Ping Feng San, has shown efficacy in preventing and treating early pneumonia with good clinical outcomes. However, its underlying mechanism is yet unclear.

AIM OF THE STUDY

To clarify the preventive and therapeutic effects of SWQ on lipopolysaccharide (LPS)-induced acute lung injury (ALI) and explore the underlying mechanism by which SWQ influences pneumonia.

MATERIALS AND METHODS

First, the chemical composition of SWQ was preliminarily determined by high performance liquid chromatography (HPLC), and the impact of SWQ (3.27, 6.55, and 13.1 g/kg) was assessed in the LPS-induced ALI rat model. Next, its inflammatory pathway was determined via network pharmacology. Finally, the molecular mechanism of SWQ was validated using a rat ALI model and a THP-1 cell inflammation model.

RESULTS

HPLC identified chlorogenic acid, prime-O-glucosylcimifugin, calycosin, and 5-O-methylaminoside in the chemical profile of SWQ. In the ALI model, SWQ alleviated ALI by reducing lung wet/dry weight ratio (W/D) and preventing histopathological damage to the lungs. At the same time, SWQ decreased penetration of inflammatory mediators by upregulating AQP1 and AQP5 and endothelial nitric oxide synthase (eNOS). Pretreatment with SWQ downregulated white blood cells and neutrophils count in BALF and suppressed LPS-induced expression levels of MPO, NE, and pro-inflammatory factors (TNF-α, IL-1β, IL-6, and iNOS). Network pharmacology showed that SWQ was associated with TLR4/NF-κB inflammation pathway. Moreover, pretreatment with SWQ reduced the expression level of TLR4/NF-κB signaling pathway-associated proteins (TLR4, Myd88, p-IκB, and p-p65) and NLRP3 inflammasome (NLRP3, ASC, caspase-1, and cleaved-IL-1β) in vivo and vitro.

CONCLUSIONS

The present study demonstrates that SWQ can reduce inflammation in ALI by inhibiting TLR4/NF-κB and NLRP3 inflammasome activation.

Highly pathogenic porcine reproductive and respiratory syndrome virus-induced inflammatory response in porcine pulmonary microvascular endothelial cells and effects of herbal ingredients on main inflammatory molecules

The role of microvascular endothelial cells (MVECs) in viral infection has received increasing attention. Our previous study demonstrated the susceptibility of porcine pulmonary MVECs to highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV), while their responses to the viral infection remain unclear. This study aimed to understand effects of the HP-PRRSV infection on functions of porcine pulmonary MVECs and the intervention effects of Chinese herbal ingredients on them. Highly purified porcine pulmonary MVECs were separated using CD31-immunomagnetic beads and infected with HP-PRRSV JXA1 and HN strain. The virus particles in cells and the ultrastructural pathological changes of cells were revealed by transmission electron microscopy. High-throughput transcriptome sequencing indicated that 104 and 228 genes were differentially expressed at 36 h post-infection, respectively, including many inflammatory molecules such as interleukins, chemokines, and adhesion molecules. The expression kinetics of HP-PRRSV-induced IL-1α, IL-6, IL-8, and VCAM-1 were characterized at the mRNA and protein levels. Luteolin significantly down-regulated HP-PRRSV-induced increase of the four molecules at both levels, and glycyrrhetinic acid and baicalin reduced that of IL-6 and VCAM-1. Our results suggest that porcine pulmonary MVECs play important roles in the inflammatory lung injury caused by HP-PRRSV infection and that herbal ingredients have potential regulatory effects on the HP-PRRSV-induced dysfunction of MVECs.

The protective effects of baicalin for respiratory diseases: an update and future perspectives

Background: Respiratory diseases are common and frequent diseases. Due to the high pathogenicity and side effects of respiratory diseases, the discovery of new strategies for drug treatment is a hot area of research. Scutellaria baicalensis Georgi (SBG) has been used as a medicinal herb in China for over 2000 years. Baicalin (BA) is a flavonoid active ingredient extracted from SBG that BA has been found to exert various pharmacological effects against respiratory diseases. However, there is no comprehensive review of the mechanism of the effects of BA in treating respiratory diseases. This review aims to summarize the current pharmacokinetics of BA, baicalin-loaded nano-delivery system, and its molecular mechanisms and therapeutical effects for treating respiratory diseases.

Method: This review reviewed databases such as PubMed, NCBI, and Web of Science from their inception to 13 December 2022, in which literature was related to “baicalin”, “Scutellaria baicalensis Georgi”, “COVID-19”, “acute lung injury”, “pulmonary arterial hypertension”, “asthma”, “chronic obstructive pulmonary disease”, “pulmonary fibrosis”, “lung cancer”, “pharmacokinetics”, “liposomes”, “nano-emulsions”, “micelles”, “phospholipid complexes”, “solid dispersions”, “inclusion complexes”, and other terms.

Result: The pharmacokinetics of BA involves mainly gastrointestinal hydrolysis, the enteroglycoside cycle, multiple metabolic pathways, and excretion in bile and urine. Due to the poor bioavailability and solubility of BA, liposomes, nano-emulsions, micelles, phospholipid complexes, solid dispersions, and inclusion complexes of BA have been developed to improve its bioavailability, lung targeting, and solubility. BA exerts potent effects mainly by mediating upstream oxidative stress, inflammation, apoptosis, and immune response pathways. It regulates are the NF-κB, PI3K/AKT, TGF-β/Smad, Nrf2/HO-1, and ERK/GSK3β pathways.

Conclusion: This review presents comprehensive information on BA about pharmacokinetics, baicalin-loaded nano-delivery system, and its therapeutic effects and potential pharmacological mechanisms in respiratory diseases. The available studies suggest that BA has excellent possible treatment of respiratory diseases and is worthy of further investigation and development.

Prediction of acute lung injury in severe acute pancreatitis by routine clinical data

AIM

Acute lung injury (ALI) is a common complication of severe acute pancreatitis (SAP) with a high mortality. Early prediction of patients at risk in initial stage can improve the long-term survival.

METHODS

A total of 91 patients with SAP out of 1647 acute pancreatitis patients from January 2015 to December 2020 were considered. A predictive model for SAP-associated ALI was constructed based on the valuable risk factors identified from routine clinical characteristics and plasma biomarkers. The value of the model was evaluated and compared with Lung Injury Prediction Score (LIPS). A nomogram was built to visualize the model.

RESULTS

Diabetes, oxygen supplementation, neutrophil count and D-dimer were found to be associated with ALI in SAP. The predictive model based on these factors had an area under the receiver operating characteristic curve [AUC: 0.88, 95% confidence interval (CI): 0.81-0.95], which was superior to LIPS (AUC: 0.71, 95% CI: 0.60-0.83), also with the higher sensitivity (65%) and specificity (96%) than LIPS (62%, 74%, respectively). Decision curve analysis of the model showed a higher net benefit than LIPS. Visualization by a nomogram facilitated the application of the model.

CONCLUSION

Diabetes, oxygen supplementation, neutrophil count and D-dimer were risk factors for SAP-associated ALI. The combination of these routine clinical data and the model visualization by a nomogram provided a simple and effective way in predicting ALI in the early phase of SAP.

Gastric Aspiration and Ventilator-Induced Model of Acute Respiratory Distress Syndrome in Swine

INTRODUCTION

Mainstays of current treatment for acute respiratory distress syndrome (ARDS) focus on supportive care and rely on intrinsic organ recovery. Animal models of ARDS are often limited by systemic injury. We hypothesize that superimposing gastric aspiration and ventilator-induced injury will induce a lung-specific injury model of severe ARDS.

MATERIALS AND METHODS

Adult swine (n = 8) were subject to a 12 h injury development period followed by 24 h of post-injury monitoring. Lung injury was induced with gastric secretions (3 cc/kg body weight/lung, pH 1-2) instilled to bilateral mainstem bronchi under direct bronchoscopic vision. Ventilator settings within the injury period contradicted baseline settings using high tidal volumes and low positive end-expiratory pressure. Baseline settings were restored following the injury period. Arterial oxygenation and lung compliance were monitored.

RESULTS

At 12 h, PaO2/FiO2 ratio and static and dynamic compliance were significantly reduced from baseline (P < 0.05). During the postinjury period, animals showed no signs of recovery in PaO2/FiO2 ratio and lung compliance. Lung edema (wet/dry weight ratio) of injured lungs was significantly elevated versus noninjured lungs (8.5 ± 1.7 versus 5.6 ± 0.3, P = 0.009). Expression of proinflammatory cytokines IL-6 and IL-8 were significantly elevated in injured lungs (P < 0.05).

CONCLUSIONS

Twelve hours of high tidal volume and low positive end-expiratory pressure in conjunction with low-pH gastric content instillation produces significant acute lung injury in swine. This large animal model may be useful for testing severe ARDS treatment strategies.

Impairment of antiviral immune response and disruption of cellular functions by SARS-CoV-2 ORF7a and ORF7b

SARS-CoV-2, the causative agent of the present COVID-19 pandemic, possesses eleven accessory proteins encoded in its genome, and some have been implicated in facilitating infection and pathogenesis through their interaction with cellular components. Among these proteins, accessory protein ORF7a and ORF7b functions are poorly understood. In this study, A549 cells were transduced to express ORF7a and ORF7b, respectively, to explore more in depth the role of each accessory protein in the pathological manifestation leading to COVID-19. Bioinformatic analysis and integration of transcriptome results identified defined canonical pathways and functional groupings revealing that after expression of ORF7a or ORF7b, the lung cells are potentially altered to create conditions more favorable for SARS-CoV-2, by inhibiting the IFN-I response, increasing proinflammatory cytokines release, and altering cell metabolic activity and adhesion. Based on these results, it is plausible to suggest that ORF7a or ORF7b could be used as biomarkers of progression in this pandemic.

Severe acute pancreatitis exhibits distinct cytokine signatures and trajectories in humans: a prospective observational study

Severe acute pancreatitis (SAP) is associated with substantial morbidity and mortality. Several cytokines have been identified to have pathophysiological significance in SAP, but studies characterizing their early trajectories are lacking. Here we characterize the early trajectories of seven key cytokines associated with SAP and compare them with non-SAP subjects. Five proinflammatory cytokines (angiopoietin-2, interleukin-6, interleukin-8, monocyte chemoattractant protein-1, resistin) and two anti-inflammatory cytokines (hepatocyte growth factor, and soluble tumor necrosis factor-α receptor-1A) were measured in a prospective cohort of acute pancreatitis subjects (2012-2016) at the time of enrollment and then every 24 h for 5 days or until discharge. The cytokines' levels and trajectories were calibrated based on date of pain onset and were compared between healthy controls and three severity categories (mild, moderate, and severe). The cohort (n = 170) consisted of 27 healthy controls, 65 mild, 38 moderate, and 40 SAP. From day 1 of symptom onset, SAP subjects exhibited significantly higher levels of both pro- and anti-inflammatory cytokines compared with non-SAP and healthy subjects. But in SAP subjects, all proinflammatory cytokines' levels trended downward after day 2 (except for a flat slope for angiopoeitin-2) whereas for non-SAP subjects, the trajectory was upward: this trajectory difference between SAP versus non-SAP subjects resulted in narrowing of the differences initially seen on day 1 for proinflammatory cytokines. For anti-inflammatory cytokines, the trajectories were uniformly upward for both SAP and non-SAP subjects. Proinflammatory cytokine response is an early and time-sensitive event in SAP that should be accounted for when designing future biomarker studies and/or therapeutic trials.NEW & NOTEWORTHY In this study, we showed that the proinflammatory cytokine response in SAP is an early event, with subsequent downregulation of proinflammatory cytokines beginning at day 1 of symptom onset. Our findings underscore the importance of enrolling subjects very early in the disease course when conducting studies to investigate early immune events of SAP; this current study also serves as an important reference for the design of future biomarker studies and therapeutic trials in SAP.

Molecular mechanism of Pulmonary diseases caused by exposure to urban PM2.5 in Chengdu-Chongqing Economic Circle, China

Chengdu-Chongqing Economic Circle (CD-CQ Economic Circle) is one of China's four major economic circles and five major urban agglomerations located in Southwest China's Sichuan Basin. The CD-CQ Economic Circle, with its strong economic development and dense population, suffers from severe PM_2.5 pollution, which is known to cause chronic and acute respiratory ailments. This study examined the lung disease-related hub genes, functions, and pathways that are affected by PM_2.5 in summer and winter in the two central megacities of Chengdu and Chongqing. PM_2.5 frequently activates lung disease-associated hub genes, most notably the transcription factor TP53. TP53 interacts with the majority of lung disease-related genes and regulates important and commonly occurring biological functions and pathways, including gland development, aging, reactive oxygen species metabolic process, the response to oxygen levels, and fluid shear stress, among others. Thus, PM_2.5 has been shown to target TP53 for regulating lung disease genes/functions/pathways, thereby influencing the occurrence and progression of lung illnesses. Notably, PM_2.5 may be associated with small cell carcinoma of the lung due to the high number of lung disease genes, hub genes, critical functions, and pathways enriched in this kind of cancer. These findings shed fresh light on the molecular pathophysiology of PM_2.5 pollution on the respiratory system in the CD-CQ Economic Circle and aid in the development of novel techniques for mitigating PM_2.5 pollution-associated respiratory illness.

The Reaction Pathway of miR-30c-5p Activates Lipopolysaccharide Promoting the Course of Traumatic and Hemorrhagic Shock Acute Lung Injury

Acute lung injury (ALI) is an acute hypoxic respiratory failure caused by diffuse inflammatory injury in alveolar epithelial cells during severe infection, trauma, and shock. Among them, trauma/hemorrhagic shock (T/HS) is the main type of indirect lung injury. Despite a great number of clinical studies, indirect factor trauma/hemorrhagic shock to the function and the mechanism in acute lung injury is not clear yet. Therefore, it is still necessary to carry on relevant analysis in order to thoroughly explore its molecular and cellular mechanisms and the pathway of disease function. In our research, we aimed to identify potential pathogenic genes and do modular analysis by downloading disease-related gene expression profile data. And our dataset is from the NCBI-GEO database. Then, we used the Clusterprofiler R package, GO function, and KEGG pathway enrichment analysis to analyze the core module genes. In addition, we also identified key transcription factors and noncoding RNAs. Based on the high degree of interaction of potential pathogenic genes and their involved functions and pathways, we identified 17 dysfunction modules. Among them, up to 9 modules significantly regulate the response to bacterial-derived molecules, and the response to lipopolysaccharide and other related functional pathways that mediate disease development. In addition, miR-290, miR-30c-5p, miR-195-5p, and miR-1-3p-based ncRNA and Jun, Atf1, and Atf3-based transcription factors have a total of 80 transcription drivers for functional modules. In summary, this study confirmed that miR-30c-5p activates lipopolysaccharide response pathway to promote the pathogenesis of ALI induced by hemorrhagic shock. This result can be an important direction for further research on related deepening diseases such as acute respiratory distress syndrome (ARDS). It further provides a piece of scientific medical evidence for revealing the pathogenic principle and cure difficulty of acute lung injury and also provides important guidance for the design of therapeutic strategies and drug development.

Friend or Foe? The Roles of Antioxidants in Acute Lung Injury

Acute lung injury (ALI) is an acute hypoxic respiratory insufficiency caused by various intra- and extra-pulmonary injury factors. The oxidative stress caused by excessive reactive oxygen species (ROS) produced in the lungs plays an important role in the pathogenesis of ALI. ROS is a "double-edged sword", which is widely involved in signal transduction and the life process of cells at a physiological concentration. However, excessive ROS can cause mitochondrial oxidative stress, leading to the occurrence of various diseases. It is well-known that antioxidants can alleviate ALI by scavenging ROS. Nevertheless, more and more studies found that antioxidants have no significant effect on severe organ injury, and may even aggravate organ injury and reduce the survival rate of patients. Our study introduces the application of antioxidants in ALI, and explore the mechanisms of antioxidants failure in various diseases including it.

Design, synthesis and structure-activity relationship studies of 4-indole-2-arylaminopyrimidine derivatives as anti-inflammatory agents for acute lung injury

Acute lung injury/acute respiratory distress syndrome (ALI/ARDS), a clinically high mortality disease, has not been effectively treated till now, and the development of anti-acute lung injury drugs is imminent. Acute lung injury was efficiently treated by inhibiting the cascade of inflammation, and reducing the inflammatory response in the lung. A series of novel compounds with highly efficient inhibiting the expression of inflammatory factors were designed by using 4-indolyl-2-aminopyrimidine as the core skeleton. Totally eleven 4-indolyl-2-arylaminopyrimidine derivatives were designed and synthesized. As well, the related anti-ALI activity of these compounds was evaluated. Compounds 6c and 6h showed a superior activity among these compounds, and the inhibition rate of IL-6 and IL-8 release ranged from 62% to 77%, and from 65% to 72%, respectively. Furthermore, most of compounds had no significant cytotoxicity in vitro. The infiltration of inflammatory cells into lung tissue significantly reduced by using compound 6h (20 mg/kg) in the ALI mice model, which achieved the effect of protecting lung tissue and improving ALI. In addition, the inflammatory response was inhibited by using compound 6h through inhibiting phosphorylation of p-38 and ERK in MAPK signaling pathway, and resulted in protective effect on ALI. These data indicated that compound 6h showed good anti-inflammatory activity in vitro and in vivo, which was expected to become a leading compound for the treatment of ALI.

Apelin-13-Mediated AMPK ameliorates endothelial barrier dysfunction in acute lung injury mice via improvement of mitochondrial function and autophagy

Maintaining the pulmonary endothelial barrier that prevents the exudation of inflammatory factors and proteins is the key to the treatment of acute lung injury (ALI). Apelin-13 plays an important role in vascular diseases; however, the protective effects of Apelin-13 on ALI with pulmonary endothelial barrier are unknown. Therefore, mice and human umbilical vein endothelial cells (HUVECs) were injured by LPS following Apelin-13 administration. ALI mice showed reduced pulmonary vascular permeability, adhesion junction, mitochondrial function, mitochondrial biogenesis, and autophagy compared to the control group. Apelin-13 administration in ALI mice ameliorated LPS-induced lung injury, pulmonary vascular permeability, mitochondrial function, and promoted autophagic flux in mice and HUVECs. However, the effect of Apelin-13 was reduced after AMPK inhibition using Compound C. These data suggest that Apelin-13 ameliorates pulmonary vascular permeability in mice with ALI induced by LPS, which may be related to enhanced phosphorylation of AMPK to regulate mitochondrial function and autophagy.

Tomatidine Improves Pulmonary Inflammation in Mice with Acute Lung Injury

Tomatidine, which is isolated from green tomato, can ameliorate inflammation and oxidative stress in cells and animal experiments and has been shown to improve airway inflammation in a murine model of asthma. Here, we investigated whether tomatidine can ameliorate acute lung injury in mice. Mice were given tomatidine by intraperitoneal injection for 7 consecutive days, and then, lung injury was induced via intratracheal instillation of lipopolysaccharide (LPS). Tomatidine reduced inflammatory cytokine expressions in bronchoalveolar lavage fluid (BALF), attenuated neutrophil infiltration in the BALF and lung tissue, increased superoxide dismutase activity and glutathione levels, and alleviated myeloperoxidase expression in the lung tissue of mice with lung injury. Tomatidine also decreased inflammatory cytokine and chemokine gene expression in inflammatory lungs and attenuated the phosphorylation of mitogen-activated protein kinase and nuclear factor kappa B. Furthermore, tomatidine enhanced the production of heme oxygenase-1, decreased the secretion of inflammatory cytokines and chemokines in LPS-stimulated lung epithelial cells, and attenuated THP-1 monocyte adhesion. Our findings suggest that tomatidine attenuates oxidative stress and inflammation, improving acute lung injury in mice.

A novel miRNA-762/NFIX pathway modulates LPS-induced acute lung injury

Severe acute lung injury (ALI) cause significant morbidity and mortality worldwide. MicroRNAs (miRNAs) are possible biomarkers and therapeutic targets for ALI. We aimed to explore the role of miR-762, a known oncogenic factor, in the pathogenesis of ALI. Levels of miR-762 in lung tissues of LPS-treated ALI mice and blood cells of patients with lung injury were measured. Injury of human lung epithelial cell line A549 was induced by LPS stimulation. A downstream target of miR-762, NFIX, was predicted using online tools. Their interactions were validated by luciferase reporter assay. Effects of targeted regulation of the miR-762/NFIX axis on cell proliferation, apoptosis, and inflammatory responses were tested in vitro in A549 cells in vivo with an ALI mouse model. We found that upregulation of miR-762 expression and downregulation of NFIX expression were associated with lung injury. Either miR-762 inhibition or NFIX overexpression in A549 lung cells significantly attenuated LPS-mediated impairment of cell proliferation and viability. Notably, increasing expressions of miR-762 inhibitor or NFIX in vivo via airway lentivirus infection alleviated the LPS-induced ALI in mice. Further, targeted downregulation of miR-762 expression or upregulation of NFIX expression in A549 cells markedly down-regulates NF-κB/IRF3 activation, and substantially reduces the production of inflammatory factors, including TNF-α, IL-6, and IL-8. This study reveals a novel role for the miR-762/NFIX pathway in ALI pathogenesis and sheds new light on targeting this pathway for diagnosis, prevention, and therapy.

The Chlamydia psittaci Inclusion Membrane Protein 0556 Inhibits Human Neutrophils Apoptosis Through PI3K/AKT and NF-κB Signaling Pathways

Inclusion membrane proteins (Incs) play an important role in the structure and stability of chlamydial inclusion and the interaction between Chlamydia spp. and their hosts. Following Chlamydia infection through the respiratory tract, human polymorphonuclear neutrophils (hPMN) not only act as the primary immune cells reaching the lungs, but also serve as reservoir for Chlamydia. We have previously identified a Chlamydia psittaci hypothetical protein, CPSIT_0556, as a medium expressed inclusion membrane protein. However, the role of inclusion membrane protein, CPSIT_0556 in regulating hPMN functions remains unknown. In the present study, we found that CPSIT_0556 could not only inhibit hPMN apoptosis through the PI3K/Akt and NF-κB signaling pathways by releasing IL-8, but also delays procaspase-3 processing and inhibits caspase-3 activity in hPMN. Up-regulating the expression of anti-apoptotic protein Mcl-1 and down-regulating the expression of pro-apoptotic protein Bax could also inhibit the translocalization of Bax in the cytoplasm into the mitochondria, as well as induce the transfer of p65 NF-κB from the cytoplasm to the nucleus. Overall, our findings demonstrate that CPSIT_0556 could inhibit hPMN apoptosis through PI3K/Akt and NF-κB pathways and provide new insights towards understanding a better understanding of the molecular pathogenesis and immune escape mechanisms of C. psittaci.

The α2AR/Caveolin-1/p38MAPK/NF-κB axis explains dexmedetomidine protection against lung injury following intestinal ischaemia-reperfusion

Intestinal ischaemia-reperfusion (I/R) injury can result in acute lung injury due to ischaemia and hypoxia. Dexmedetomidine (Dex), a highly selective alpha2-noradrenergic receptor (α2AR) agonist used in anaesthesia, is reported to regulate inflammation in organs. This study aimed to investigate the role and mechanism of Dex in lung injury caused by intestinal I/R. After establishing a rat model of intestinal I/R, we measured the wet-to-dry specific gravity of rat lungs upon treatments with Dex, SB239063 and the α2AR antagonist Atipamezole. Moreover, injury scoring and histopathological studies of lung tissues were performed, followed by ELISA detection on tumour necrosis factor-α (TNF-α), interleukin (IL)-1β and IL-6 expression. Correlation of Caveolin-1 (Cav-1) protein expression with p38, p-p38, p-p65 and p65 in rat lung tissues was analysed, and the degree of cell apoptosis in lung tissues after intestinal I/R injury was detected by TUNEL assay. The lung injury induced by intestinal I/R was a dynamic process. Moreover, Dex had protective effects against lung injury by mediating the expression of Cal-1 and α2A -AR. Specifically, Dex promoted Cav-1 expression via α2A -AR activation and mitigated intestinal I/R-induced lung injury, even in the presence of Atipamezole. The protective effect of Dex on intestinal I/R-induced lung injury was also closely related to α2A -AR/p38 mitogen-activated protein kinases/nuclear factor-kappaB (MAPK/NF-κB) pathway. Dex can alleviate pulmonary inflammation after in intestinal I/R by promoting Cav-1 to inhibit the activation of p38 and NF-κB. In conclusion, Dex can reduce pulmonary inflammatory response even after receiving threats from both intestinal I/R injury and Atipamezole.

SARS-CoV-2 Induces Lymphocytopenia by Promoting Inflammation and Decimates Secondary Lymphoid Organs

While lymphocytopenia is a common characteristic of coronavirus disease 2019 (COVID-19), the mechanisms responsible for this lymphocyte depletion are unclear. Here, we retrospectively reviewed the clinical and immunological data from 18 fatal COVID-19 cases, results showed that these patients had severe lymphocytopenia, together with high serum levels of inflammatory cytokines (IL-6, IL-8 and IL-10), and elevation of many other mediators in routine laboratory tests, including C-reactive protein, lactate dehydrogenase, α-hydroxybutyrate dehydrogenase and natriuretic peptide type B. The spleens and hilar lymph nodes (LNs) from six additional COVID-19 patients with post-mortem examinations were also collected, histopathologic detection showed that both organs manifested severe tissue damage and lymphocyte apoptosis in these six cases. In situ hybridization assays illustrated that SARS-CoV-2 viral RNA accumulates in these tissues, and transmission electronic microscopy confirmed that coronavirus-like particles were visible in the LNs. SARS-CoV-2 Spike and Nucleocapsid protein (NP) accumulated in the spleens and LNs, and the NP antigen restricted in angiotensin-converting enzyme 2 (ACE2) positive macrophages and dendritic cells (DCs). Furthermore, SARS-CoV-2 triggered the transcription of Il6, Il8 and Il1b genes in infected primary macrophages and DCs in vitro, and SARS-CoV-2-NP⁺ macrophages and DCs also manifested high levels of IL-6 and IL-1β, which might directly decimate human spleens and LNs and subsequently lead to lymphocytopenia in vivo. Collectively, these results demonstrated that SARS-CoV-2 induced lymphocytopenia by promoting systemic inflammation and direct neutralization in human spleen and LNs.

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.

Exploration and validation of related hub gene expression during SARS-CoV-2 infection of human bronchial organoids

Background

In the novel coronavirus pandemic, the high infection rate and high mortality have seriously affected people’s health and social order. To better explore the infection mechanism and treatment, the three-dimensional structure of human bronchus has been employed in a better in-depth study on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Methods

We downloaded a separate microarray from the Integrated Gene Expression System (GEO) on a human bronchial organoids sample to identify differentially expressed genes (DEGS) and analyzed it with R software. After processing with R software, Gene Ontology (GO) and Kyoto PBMCs of Genes and Genomes (KEGG) were analyzed, while a protein–protein interaction (PPI) network was constructed to show the interactions and influence relationships between these differential genes. Finally, the selected highly connected genes, which are called hub genes, were verified in CytoHubba plug-in.

Results

In this study, a total of 966 differentially expressed genes, including 490 upregulated genes and 476 downregulated genes were used. Analysis of GO and KEGG revealed that these differentially expressed genes were significantly enriched in pathways related to immune response and cytokines. We construct protein-protein interaction network and identify 10 hub genes, including IL6, MMP9, IL1B, CXCL8, ICAM1, FGF2, EGF, CXCL10, CCL2, CCL5, CXCL1, and FN1. Finally, with the help of GSE150728, we verified that CXCl1, CXCL8, CXCL10, CCL5, EGF differently expressed before and after SARS-CoV-2 infection in clinical patients.

Conclusions

In this study, we used mRNA expression data from GSE150819 to preliminarily confirm the feasibility of hBO as an in vitro model to further study the pathogenesis and potential treatment of COVID-19. Moreover, based on the mRNA differentiated expression of this model, we found that CXCL8, CXCL10, and EGF are hub genes in the process of SARS-COV-2 infection, and we emphasized their key roles in SARS-CoV-2 infection. And we also suggested that further study of these hub genes may be beneficial to treatment, prognostic prediction of COVID-19.

BIO 300: a promising radiation countermeasure under advanced development for acute radiation syndrome and the delayed effects of acute radiation exposure

INTRODUCTION

There are no radioprotectors currently approved by the United States Food and Drug Administration (US FDA) for either the hematopoietic acute radiation syndrome (H-ARS) or for the acute radiation gastrointestinal syndrome (GI-ARS). There are currently, however, three US FDA-approved medicinals that serve to mitigate acute irradiation-associated hematopoietic injury.

AREA COVERED

We present the current status of a promising radiation countermeasure, BIO 300 (a genistein-based agent), that has been extensively investigated in murine models of H-ARS and models of the delayed effects of acute radiation exposure (DEARE) and is currently being evaluated in large animal models. It is also being developed for the prevention of radiation-induced toxicities associated with solid tumor radiotherapy and is the subject of two active Investigational New Drug (IND) applications. We have included a listing and brief review of significant investigations of this promising medical countermeasure.

EXPERT OPINION

BIO 300 is a leading radioprotector under advanced development for H-ARS and DEARE, as well as for select oncologic indication(s). Efficacy following oral administration (po), lack of clinical side effects, storage at ambient temperature, and intended dual use makes BIO 300 an ideal candidate for military and civilian use as well as for storage in the Strategic National Stockpile.

Possible Mechanisms and Special Clinical Considerations of Curcumin Supplementation in Patients with COVID-19

The novel coronavirus outbreak caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was recognized in late 2019 in Wuhan, China. Subsequently, the World Health Organization declared coronavirus disease 2019 (COVID-19) as a pandemic on 11 March 2020. The proportion of potentially fatal coronavirus infections may vary by location, age, and underlying risk factors. However, acute respiratory distress syndrome (ARDS) is the most frequent complication and leading cause of death in critically ill patients. Immunomodulatory and anti-inflammatory agents have received great attention as therapeutic strategies against COVID-19. Here, we review potential mechanisms and special clinical considerations of supplementation with curcumin as an anti-inflammatory and antioxidant compound in the setting of COVID-19 clinical research.

Novel Strategies for Endothelial Preservation in Lung Transplant Ischemia-Reperfusion Injury

Lung ischemia reperfusion (IR) injury inevitably occurs during lung transplantation. The pulmonary endothelium is the primary target of IR injury that potentially results in severe pulmonary dysfunction. Over the last decades, various molecules, receptors, and signaling pathways were identified in order to develop treatment strategies for the preservation of the pulmonary endothelium against IR injury. We here review the latest and most promising therapeutic strategies for the protection of the endothelium against IR injury. These include the stabilization of the endothelial glycocalyx, inhibition of endothelial autophagy, inhibition of adhesion molecules, targeting of angiotensin-converting enzyme, and traditional viral and novel non-viral gene transfer approaches. Though some of these strategies proved to be promising in experimental studies, very few of these treatment concepts made the transfer into clinical application. This dilemma underscores the need for more experimental evidence for the translation into clinical studies to invent therapeutic concepts against IR injury-mediated endothelial damage.

Acetylharpagide Protects Mice from Staphylococcus Aureus-Induced Acute Lung Injury by Inhibiting NF-κB Signaling Pathway

Staphylococcus aureus (S. aureus)-induced acute lung injury (ALI) is a serious disease that has a high risk of death among infants and teenagers. Acetylharpagide, a natural compound of Ajuga decumbens Thunb. (family Labiatae), has been found to have anti-tumor, anti-inflammatory and anti-viral effects. This study investigates the therapeutic effects of acetylharpagide on S. aureus-induced ALI in mice. Here, we found that acetylharpagide alleviated S. aureus-induced lung pathological morphology damage, protected the pulmonary blood-gas barrier and improved the survival of S. aureus-infected mice. Furthermore, S. aureus-induced myeloperoxidase (MPO) activity of lung homogenate and pro-inflammatory factors in bronchoalveolar lavage (BAL) fluid were suppressed by acetylharpagide. Mechanically, acetylharpagide inhibited the interaction between polyubiquitinated receptor interacting protein 1 (RIP1) and NF-κB essential modulator (NEMO), thereby suppressing NF-κB activity. In summary, these results show that acetylharpagide protects mice from S. aureus-induced ALI by suppressing the NF-κB signaling pathway. Acetylharpagide is expected to become a potential treatment for S. aureus-induced ALI.

Comprehensive pulmonary toxicity assessment of cetylpyridinium chloride using A549 cells and Sprague-Dawley rats

Cetylpyridinium chloride (CPC), a quaternary ammonium compound and cationic surfactant, is used in personal hygiene products such as toothpaste, mouthwash, and nasal spray. Although public exposure to CPC is frequent, its pulmonary toxicity has yet to be fully characterized. Due to high risks of CPC inhalation, we aimed to comprehensively elucidate the in vitro and in vivo toxicity of CPC. The results demonstrated that CPC is highly cytotoxic against the A549 cells with a half-maximal inhibitory concentration (IC₅₀ ) of 5.79 μg/ml. Following CPC exposure, via intratracheal instillation (ITI), leakage of lactate dehydrogenase, a biomarker of cell injury, was significantly increased in all exposure groups. Further, repeated exposure of rats to CPC for 28 days caused a decrease in body weight of the high-exposure group and the relative weights of the lungs and kidneys of the high recovery group, but no changes were evident in the histological and serum chemical analyses. The bronchoalveolar lavage fluid (BALF) analysis showed a significant increase in proinflammatory cytokines interleukin (IL)-6, IL-1β, and tumor necrosis factor (TNF)-α levels. ITI of CPC induced focal inflammation of the pulmonary parenchyma in rats' lungs. Our study demonstrated that TNF-α was the most commonly secreted proinflammatory cytokine during CPC exposure in both in vitro and in vivo models. Polymorphonuclear leukocytes in the BALF, which are indicators of pulmonary inflammation, significantly increased in a concentration-dependent manner in all in vivo studies including the ITI, acute, and subacute inhalation assays, demonstrating that PMNs are the most sensitive parameters of pulmonary toxicity.

Effect of Dexmedetomidine on Postoperative Lung Injury during One-Lung Ventilation in Thoracoscopic Surgery

Objective

To investigate the effect of dexmedetomidine on postoperative lung injury in patients undergoing thoracoscopic surgery.

Methods

From March 2019 to October 2019, 40 patients were randomly divided into two groups: dexmedetomidine group (group D) and control group (group C). Except recording the general condition of the patients in both groups preoperatively and intraoperatively, the oxygenation index (OI) and alveolar-arterial oxygen partial pressure difference (A-aDO₂) were monitored at admission (T0), immediately after one-lung ventilation (T1), 0.5 h after one-lung ventilation (T2), and 15 minutes after inhaling air before leaving the room (T3). The content of IL-8 in arterial blood was measured by enzyme-linked immunosorbent assay (ELISA) at T0 and T2, and the expression of AQP1 protein in isolated lung tissue was measured by immunohistochemistry and Western blot. The incidence of postoperative pulmonary complications (atelectasis, pneumonia, and acute respiratory distress syndrome) was used as the index of lung injury.

Results

There was no significant difference in the general condition before and during operation between the two groups. There was no significant difference in arterial blood IL-8 content between the two groups at the T0 time point, but the arterial blood IL-8 content at the T2 time point was significantly higher than that at the T0 time point, especially in group C. The results of immunohistochemistry and Western blot showed that the expression level of AQP1 protein in the isolated lung tissue of group D was significantly higher than that of group C (P < 0 05). At T3, the OI of group D was significantly higher than that of group C, and the A-aDO₂ of group D was significantly lower than that of group C (P < 0.05). There was no significant difference in the incidence of postoperative PPCs between the two groups.

Conclusion

Dexmedetomidine can reduce the level of plasma IL-8 and upregulate the expression of AQP1 in the lung tissue of patients undergoing thoracoscopic surgery under one-lung ventilation, but it has no significant effect on the incidence of postoperative PPCs. Dexmedetomidine can be safely used in thoracoscopic surgery and has a certain protective effect on lung injury.

Distinct lung microbiota associate with HIV-associated chronic lung disease in children

Chronic lung disease (CLD) is a common co-morbidity for HIV-positive children and adolescents on antiretroviral therapy (ART) in sub-Saharan Africa. In this population, distinct airway microbiota may differentially confer risk of CLD. In a cross-sectional study of 202 HIV-infected children aged 6-16 years in Harare, Zimbabwe, we determined the association of sputum microbiota composition (using 16S ribosomal RNA V4 gene region sequencing) with CLD defined using clinical, spirometric, or radiographic criteria. Forty-two percent of children were determined to have CLD according to our definition. Dirichlet multinomial mixtures identified four compositionally distinct sputum microbiota structures. Patients whose sputum microbiota was dominated by Haemophilus, Moraxella or Neisseria (HMN) were at 1.5 times higher risk of CLD than those with Streptococcus or Prevotella (SP)-dominated microbiota (RR = 1.48, p = 0.035). Cell-free products of HMN sputum microbiota induced features of epithelial disruption and inflammatory gene expression in vitro, indicating enhanced pathogenic potential of these CLD-associated microbiota. Thus, HIV-positive children harbor distinct sputum microbiota, with those dominated by Haemophilus, Moraxella or Neisseria associated with enhanced pathogenesis in vitro and clinical CLD.

Recombinant adiponectin protects the newborn rat lung from lipopolysaccharide-induced inflammatory injury

Preterm infants are at high risk for developing bronchopulmonary dysplasia and pulmonary hypertension from inflammatory lung injury. In adult models, adiponectin (APN)—an adipocyte‐derived hormone—protects the lung from inflammatory injury and pulmonary vascular remodeling. Cord blood APN levels in premature infants born < 26 weeks gestation are 5% of the level in infants born at term. We previously reported the expression profile of APN and its receptors in neonatal rat lung homogenates during the first 3 weeks of postnatal development. Here, we characterize the expression profile of APN and its receptors in specific lung cells and the effects of exogenous recombinant APN (rAPN) on lipopolysaccharide‐(LPS)‐induced cytokine and chemokine production in total lung homogenates and specific lung cells. In vitro, rAPN added to primary cultures of pulmonary artery smooth muscle cells attenuated the expression of LPS‐induced pro‐inflammatory cytokines while increasing the expression of anti‐inflammatory cytokines. In vivo, intraperitoneal rAPN (2 mg/kg), given 4 hr prior to intrapharyngeal administration of LPS (5 mg/kg) to newborn rats at postnatal day 4, significantly reduced gene and protein expression of the pro‐inflammatory cytokine IL‐1ß and reduced protein expression of the chemokines monocyte chemoattractant protein (MCP‐1) and macrophage inflammatory protein‐1 alpha (MIP‐1α) in the lung. LPS‐induced histopathological changes in the lung were also decreased. Moreover, rAPN given 20 hr after intrapharyngeal LPS had a similar effect on lung inflammation. These findings suggest a role for APN in protecting the lung from inflammation during early stages of lung development.

Dihydroquercetin attenuates lipopolysaccharide-induced acute lung injury through modulating FOXO3-mediated NF-κB signaling via miR-132-3p

BACKGROUND

Dihydroquercetin (DHQ) is a potent flavonoid which has been demonstrated to have multiple biological activities including anti-inflammation activity, antioxidant activity as well as anti-cancer activity etc. Recently, many studies have focused on the antioxidant activity of DHQ. However, the use of the anti-inflammation activity of DHQ in acute lung injury (ALI) has not been reported.

METHODS

Cell viability was examined by CCK-8 assay. The relative expression of miR-132-3p, FOXO3 were detected by qPCR. The levels of TNF-α, IL-6 and IL-1β were detected using enzyme-linked immunosorbent assay. The amount of apoptosis cells was detected by flow cytometry. The protein levels of Bcl-2, Bax, p-p65 and p-IκBα were measured by western blot.

RESULTS

We found that DHQ-induced the expression of miR-132-3p in LPS-induced ALI. Overexpression of miR-132-3p resulted in the inhibition of FOXO3 expression and then suppressed FOXO3-activated NF-κB pathway, attenuating LPS-induced inflammatory response and apoptosis.

CONCLUSION

We demonstrated FOXO3 to be a target of miR-132-3p, and DHQ could induce the expression of miR-132-3p, relieving LPS-induced ALI via miR-132-3p/FOXO3/NF-κB axis, providing a promising therapeutic target for ALI.

Review 1: Lung transplant-from donor selection to graft preparation

For various end-stage lung diseases, lung transplantation remains one of the only viable treatment options. While the demand for lung transplantation has steadily risen over the last few decades, the availability of donor grafts is limited, which have resulted in progressively longer waiting lists. In the early years of lung transplantation, only the 'ideal' donor grafts are considered for transplantation. Due to the donor shortages, there is ongoing discussion about the safe use of 'suboptimal' grafts to expand the donor pool. In this review, we will discuss the considerations around donor selection, donor-recipient matching, graft preparation and graft optimisation.

Pulmonary Toxicity and Inflammatory Response of E-Cigarette Vape Cartridges Containing Medium-Chain Triglycerides Oil and Vitamin E Acetate: Implications in the Pathogenesis of EVALI

Recently, there has been an outbreak of a condition named e-cigarette or vaping products-associated lung injury (EVALI). The primary components of vaping products include tetrahydrocannabinol (THC), vitamin E acetate (VEA) and medium-chain triglycerides (MCT), may be responsible for acute lung toxicity. Currently, little information is available on the physiological and biological effects of exposure to these products. We hypothesized that these CBD/counterfeit vape cartridges and their constituents (VEA and MCT) induce pulmonary toxicity, mediated by oxidative damage and inflammatory responses, leading to acute lung injury. We studied the potential mechanisms of CBD/counterfeit vape cartridge aerosol induced inflammatory response by evaluating the generation of reactive oxygen species by MCT, VEA, and cartridges and their effects on the inflammatory state of pulmonary epithelium and immune cells both in vitro and in vivo. Cells exposed to these aerosols generated reactive oxygen species, caused cytotoxicity, induced epithelial barrier dysfunction, and elicited an inflammatory response. Using a murine model, the parameters of acute toxicity to aerosol inhalation were assessed. Infiltration of neutrophils and lymphocytes was accompanied by significant increases in IL-6, eotaxin, and G-CSF in the bronchoalveolar lavage fluid (BALF). In mouse BALF, eicosanoid inflammatory mediators, leukotrienes, were significantly increased. Plasma from e-cig users also showed increased levels of hydroxyeicosatetraenoic acid (HETEs) and various eicosanoids. Exposure to CBD/counterfeit vape cartridge aerosols showed the most significant effects and toxicity compared to MCT and VEA. In addition, we determined SARS-CoV-2 related proteins and found no impact associated with aerosol exposures from these tested cartridges. Overall, this study demonstrates acute exposure to specific CBD/counterfeit vape cartridges induces in vitro cytotoxicity, barrier dysfunction, and inflammation and in vivo mouse exposure induces acute inflammation with elevated proinflammatory markers in the pathogenesis of EVALI.

Pulmonary toxicity and inflammatory response of e-cigarettes containing medium-chain triglyceride oil and vitamin E acetate: Implications in the pathogenesis of EVALI but independent of SARS-COV-2 COVID-19 related proteins

Recently, there has been an outbreak associated with the use of e-cigarette or vaping products, associated lung injury (EVALI). The primary components of vaping products, vitamin E acetate (VEA) and medium-chain triglycerides (MCT) may be responsible for acute lung toxicity. Currently, little information is available on the physiological and biological effects of exposure to these products. We hypothesized that these e-cig cartridges and their constituents (VEA and MCT) induce pulmonary toxicity, mediated by oxidative damage and inflammatory responses, leading to acute lung injury. We studied the potential mechanisms of cartridge aerosol induced inflammatory response by evaluating the generation of reactive oxygen species by MCT, VEA, and cartridges, and their effects on the inflammatory state of pulmonary epithelium and immune cells both in vitro and in vivo. Cells exposed to these aerosols generated reactive oxygen species, caused cytotoxicity, induced epithelial barrier dysfunction, and elicited an inflammatory response. Using a murine model, the parameters of acute toxicity to aerosol inhalation were assessed. Infiltration of neutrophils and lymphocytes was accompanied by significant increases in IL-6, eotaxin, and G-CSF in the bronchoalveolar lavage fluid (BALF). In mouse plasma, eicosanoid inflammatory mediators, leukotrienes, were significantly increased. Plasma from e-cig users also showed increased levels of hydroxyeicosatetraenoic acid (HETEs) and various eicosanoids. Exposure to e-cig cartridge aerosols showed the most significant effects and toxicity compared to MCT and VEA. In addition, we determined at SARS-COV-2 related proteins and found no impact associated with aerosol exposures from these tested cartridges. Overall, this study demonstrates acute exposure to specific e-cig cartridges induces in vitro cytotoxicity, barrier dysfunction, and inflammation and in vivo mouse exposure induces acute inflammation with elevated pro-inflammatory markers in the pathogenesis of EVALI.

Pro-inflammatory cytokine ratios determine the clinical course of febrile neutropenia in children receiving chemotherapy

Background

Febrile neutropenia is a common and serious complication during treatment of childhood cancer. Empirical broad-spectrum antibiotics are usually administered until neutrophil cell count recovery. It was the aim of this study to investigate cytokine profiles as potential biomarkers using in-vitro sepsis models to differentiate between distinct clinical courses of febrile neutropenia (FN).

Methods

We conducted an observational study in FN episodes of pediatric oncology patients. Courses of neutropenia were defined as severe in case of proven blood stream infection or clinical evidence of complicated infection. We collected blood samples at various time points from the onset of FN and stimulated ex vivo with lipopolysaccharide (LPS) and Staphylococcus epidermidis (SE) for 24 h. Twenty-seven cytokine levels were measured in the whole blood culture supernatants by a multiplex immunoassay system.

Results

Forty-seven FN episodes from 33 children were investigated. IL-8, IL-1β, and MCP-1 expression increased significantly over time. IL-8, MIP-1α, MIP-1β, MCP-1, and TNF-α showed significantly lower concentration in patients with a clinically severe course of the FN.

Conclusions

Distinct patterns of cytokine profiles seem to be able to determine infectious FN and to predict the severity of its clinical course. If these data can be verified in a multi-centre setting, this may finally lead to an individualized treatment strategy facilitating antibiotic stewardship in these patients.

A hypothesized role for dysregulated bradykinin signaling in COVID-19 respiratory complications

As of April 20, 2020, over time, the COVID-19 pandemic has resulted in 157 970 deaths out of 2 319 066 confirmed cases, at a Case Fatality Rate of ~6.8%. With the pandemic rapidly spreading, and health delivery systems being overwhelmed, it is imperative that safe and effective pharmacotherapeutic strategies are rapidly explored to improve survival. In this paper, we use established and emerging evidence to propose a testable hypothesis that, a vicious positive feedback loop of des-Arg(9)-bradykinin- and bradykinin-mediated inflammation → injury → inflammation, likely precipitates life threatening respiratory complications in COVID-19. Through our hypothesis, we make the prediction that the FDA-approved molecule, icatibant, might be able to interrupt this feedback loop and, thereby, improve the clinical outcomes. This hypothesis could lead to basic, translational, and clinical studies aimed at reducing COVID-19 morbidity and mortality.

Impact of Bacterial Toxins in the Lungs

Bacterial toxins play a key role in the pathogenesis of lung disease. Based on their structural and functional properties, they employ various strategies to modulate lung barrier function and to impair host defense in order to promote infection. Although in general, these toxins target common cellular signaling pathways and host compartments, toxin- and cell-specific effects have also been reported. Toxins can affect resident pulmonary cells involved in alveolar fluid clearance (AFC) and barrier function through impairing vectorial Na⁺ transport and through cytoskeletal collapse, as such, destroying cell-cell adhesions. The resulting loss of alveolar-capillary barrier integrity and fluid clearance capacity will induce capillary leak and foster edema formation, which will in turn impair gas exchange and endanger the survival of the host. Toxins modulate or neutralize protective host cell mechanisms of both the innate and adaptive immunity response during chronic infection. In particular, toxins can either recruit or kill central players of the lung's innate immune responses to pathogenic attacks, i.e., alveolar macrophages (AMs) and neutrophils. Pulmonary disorders resulting from these toxin actions include, e.g., acute lung injury (ALI), the acute respiratory syndrome (ARDS), and severe pneumonia. When acute infection converts to persistence, i.e., colonization and chronic infection, lung diseases, such as bronchitis, chronic obstructive pulmonary disease (COPD), and cystic fibrosis (CF) can arise. The aim of this review is to discuss the impact of bacterial toxins in the lungs and the resulting outcomes for pathogenesis, their roles in promoting bacterial dissemination, and bacterial survival in disease progression.

Cytokines in Inflammatory Disease

This review aims to briefly discuss a short list of a broad variety of inflammatory cytokines. Numerous studies have implicated that inflammatory cytokines exert important effects with regard to various inflammatory diseases, yet the reports on their specific roles are not always consistent. They can be used as biomarkers to indicate or monitor disease or its progress, and also may serve as clinically applicable parameters for therapies. Yet, their precise role is not always clearly defined. Thus, in this review, we focus on the existing literature dealing with the biology of cytokines interleukin (IL)-6, IL-1, IL-33, tumor necrosis factor-alpha (TNF-α), IL-10, and IL-8. We will briefly focus on the correlations and role of these inflammatory mediators in the genesis of inflammatory impacts (e.g., shock, trauma, immune dysregulation, osteoporosis, and/or critical illness).

Lung allograft donors with excessive alcohol use have increased levels of human antimicrobial peptide LL-37

The relatively low long-term survival rate of lung transplant recipients as compared to other organ recipients serves as an impetus to identify potential lung dysfunction as early as possible. There is an association between donor heavy alcohol use and acute lung injury in the lung allograft after transplant, known as primary graft dysfunction. Excessive alcohol use (EAU) can induce pulmonary immune dysregulation in response to an infection. Antimicrobial peptides (AMPs) are an important component of the innate immune response to pulmonary infections, but the impact of EAU on AMPs in the allograft lung has not been evaluated. Our hypothesis is that specific lung AMPs, LL-37, α-defensin-1,2,3, and β-defensin-2, are dysregulated in the lungs from organ donors who had EAU. In this prospective observational investigation, we measured AMPs via ELISA and inflammatory cytokines via multiplex bead array, in bronchoalveolar lavage (BAL) fluid of lung allograft donors, comparing results based on their alcohol consumption. LL-37 levels in lung donors with EAU were found to be increased compared to nondrinker (ND) donors [median 7.7 ng/mL (IQR 4.1-37.0) vs. 2.3 ng/mL (IQR 1.1-7.9), p = 0.004], whereas α-defensins-1,2,3 were decreased only in the presence of an infection in donors with EAU compared to ND donors [median 2.2 ng/mL (IQR 1.6-2.4) vs. 3.2 ng/mL (IQR 2.3-3.8), p = 0.049]. There was no difference in β-defensin-2 levels. Gene expression levels of these AMPs were not different. Elevated levels of CXCL8 were noted in bronchial washings of donors with EAU compared to ND donors, [median 4372 pg/mL (IQR 3352-13180) vs. 867.3 pg/mL (IQR 163.6-3675), p = 0.04], suggesting a potentially heightened inflammatory response. At 1 month post-transplant, LL-37 and CXCL8 levels are decreased compared to levels at time of transplant. In lung donors with EAU, LL-37 and α-defensins-1,2,3 dysregulated levels in the presence of an infection may be a harbinger of dysfunction of the lungs through the transplant process.

Immune response during influenza virus infection among the population of Assam, Northeast India

Introduction

The pathogenicity of influenza virus infection is modulated by the cytokine expressions in patients. The present study was aimed to measure some important pro- and anti-inflammatory cytokines in influenza-infected population of Assam, Northeast India.

Materials and Methods

Influenza viruses consisting of subtypes influenza A(H1N1)pdm09, H3N2 and influenza-B were detected in patients with symptoms of influenza-like-illness by Real-time reverse transcriptase polymerase chain reaction (RT-PCR) method. Relative messenger ribonucleic acid (mRNA) quantification of four pro-inflammatory cytokines (interleukin [IL]-6, IL-8, interferon-gamma [IFN-γ] and tumour necrosis factor-alpha [TNF-α]) and one anti-inflammatory cytokine (IL-10) were measured in influenza-positive cases and non-influenza controls, by real-time RT-PCR. The plasma concentration of the cytokines was determined using cytometric-bead-array with flow cytometry.

Results

Influenza viruses were detected in 14.28% (50/350) of 350 patients screened. The expression of IL-6 was significantly raised in cases compared to controls (P = 0.018). IL-8 and IL-10 were also raised in cases, compared to controls (P = 0.284 and P = 0.018). An increased plasma TNF-α was observed in cases (1.36-fold and P = 0.289). The mRNA expression of IFN-γ was also increased in cases compared to controls (0.87-fold). However, the plasma level of IFN-γ was higher in the non-influenza controls compared to cases.

Conclusions

The study revealed a differential cytokine profile during influenza virus infection in the population, which may influence disease severity. An extended study on host immune response may provide better insights for the use of cytokine antagonists in therapeutic treatments among severe cases of influenza virus infection.

EASIX and mortality after allogeneic stem cell transplantation

Allogeneic stem cell transplantation (alloSCT) is an effective immunotherapy in patients with hematological malignancies. Endothelial dysfunction was linked to major complications after alloSCT. We asked the question if the "Endothelial Activation and Stress Index" (EASIX; [(creatinine × LDH) ÷ thrombocytes]) can predict mortality after alloSCT. We performed a retrospective cohort analysis in five alloSCT centers in the USA and Germany. EASIX was assessed prior to conditioning (EASIX-pre) and correlated with mortality in 755 patients of a training cohort in multivariable models. The predictive model established in the training cohort was validated in 1267 adult allo-recipients. Increasing EASIX-pre predicted lower overall survival (OS) after alloSCT, and successful model validation was achieved for the validation cohort. We found that EASIX-pre predicts OS irrespective of established scores. Moreover, EASIX-pre was also a significant prognostic factor for transplant-associated microangiopathy. Finally, EASIX-pre correlated with biomarkers of endothelial homeostasis such as CXCL8, interleukin-18, and insulin-like-growth-factor-1 serum levels. This study establishes EASIX-pre based on a standard laboratory biomarker panel as a predictor of individual risk of mortality after alloSCT independently from established clinical criteria.

Scrub Typhus Pathogenesis: Innate Immune Response and Lung Injury During Orientia tsutsugamushi Infection

Scrub typhus is an understudied, potentially lethal disease caused by infection with Orientia tsutsugamushi. Despite causing an estimated 1 million cases per year and an increasing global presence, mechanisms of scrub typhus pathogenesis remain unclear. One of the most life-threatening conditions that can arise in scrub typhus patients is acute respiratory distress syndrome (ARDS). The development of ARDS is a complex process; some of its pathological hallmarks, including prolonged recruitment of inflammatory immune cells to the lung and vasculature damage, have been observed in humans and/or animal models of O. tsutsugamushi infection. Although different cell types and mechanisms may contribute to ARDS development during O. tsutsugamushi infection, this review highlights our current evidence of pulmonary endothelial activation and damage, the potential roles of neutrophils and macrophages in the lung, and the knowledge gaps in this field. Continued investigation of the lung microenvironment and cellular interactions will help elucidate disease pathogenesis and possible treatment during scrub typhus.