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Lipid nanoparticles (LNPs) are non-viral nucleic acid delivery systems that show great potential in vaccine development and disease treatment. Although LNPs are particularly advantageous for in vivo delivery, the wide application of LNPs is impeded as their systemic delivery of nucleic acid drugs to extrahepatic tissues remains highly challenging. To address this issue, we developed lung-targeted polyzwitterionic LNPs with zwitterionic polymer poly(2-methyacryloyloxyethyl phosphorylcholine) (PMPC) modified 1,2-dimyristoyl-sn-glycerol lipid for the delivery of small interfering RNA (siRNA). Three libraries with 90 PMPC-LNPs@siRNA were established. The polyzwitterionic PMPC-LNPs had high siRNA encapsulation efficiency of about 90%. The findings revealed that polyzwitterionic PMPC-LNPs@siRNA absorbed protein corona with the main component of Vitronectin, mediating lung-targeted delivery of siRNA. With good cellular uptake and endo/lysosomal escape ability, in vitro and in vivo studies demonstrated that polyzwitterionic PMPC-LNPs with siRNA against tumor necrosis factor-α (TNF-α) could significantly down-regulate the TNF-α in mRNA and protein levels, and improved the pathological features of lung inflammation. Polyzwitterionic PMPC-LNPs@siRNA achieved safe and efficient treatment of lung inflammation. Therefore, this work offered a promising siRNA therapeutic approach for lung diseases. [ABSTRACT FROM AUTHOR]

Exposure to diesel exhaust is associated with increased risk of cardiovascular and lung disease. Substituting petroleum diesel with renewable diesel can alter emission properties but the potential health effects remain unclear. This study aimed to explore toxicity and underlying mechanisms of diesel exhaust from renewable fuels. Using proximity extension assay (Olink), 92 proteins linked to inflammation, cardiovascular function, and cancer were analyzed in bronchoalveolar lavage fluid (BALF) and plasma in mice 1 day after pulmonary exposure to exhaust particles at doses of 6, 18, and 54 µg/mouse. Particles were generated from combustion of renewable (rapeseed methyl ester, RME13, hydrogen-treated vegetable oil, HVO13; both at 13% O2 engine intake) and petroleum diesel (MK1 ultra-low-sulfur diesel at 13% and 17% O2 intake; DEP13 and DEP17). We identified positive dose–response relationships between exposure and proteins in BALF using linear models: 33 proteins for HVO13, 24 for DEP17, 22 for DEP13, and 12 for RME13 (p value < 0.05). In BALF, 11 proteins indicating cytokine signaling and inflammation (CCL2, CXCL1, CCL3L3, CSF2, IL1A, CCL20, TPP1, GDNF, LGMN, ITGB6, PDGFB) were common for all exposures. Several proteins in BALF (e.g., CCL2, CXCL1, CCL3L3, CSF2, IL1A) correlated (rs ≥ 0.5) with neutrophil cell count and DNA damage in BAL cells. Interestingly, plasma protein profiles were only affected by RME13 and, to lesser extent, by DEP13. Overall, we identified inflammation-related changes in the BALF as a common toxic mechanism for the combustion particles. Our protein-based approach enables sensitive detection of inflammatory protein changes across different matrices enhancing understanding of exhaust particle toxicity. [ABSTRACT FROM AUTHOR]

Organoid three-dimensional systems are powerful platforms to study development and disease. Recently, the complexity of lung organoid models derived from adult mouse and human stem cells has increased substantially in terms of cellular composition and structural complexity. However, a murine lung organoid system with a clear integrated endothelial compartment is still missing. Here, we describe a novel method that adds another level of intricacy to our published bronchioalveolar lung organoid (BALO) model by microinjection of FACS-sorted lung endothelial cells (ECs) into differentiated organoid cultures. Before microinjection, ECs obtained from the lung homogenate of young mice expressed typical EC markers such as CD31 and vascular endothelial cadherin and showed tube formation capacity. Following microinjection, ECs surrounded the BALO's alveolar-like compartment, aligning with type I and type II alveolar epithelial cells, as demonstrated by confocal and electron microscopy. Notably, expression of Car4 and Aplnr was as well detected, suggesting the presence of EC microvascular phenotypes in the cultured ECs. Moreover, upon epithelial cell injury by LPS and influenza A virus, endothelialized BALOs released proinflammatory cytokines, leading to the upregulation ICAM-1 (intercellular adhesion molecule 1) in ECs. In summary, we characterized for the first time an organoid model that incorporates ECs into the alveolar structures of lung organoids, not only increasing our previous model's cellular and structural complexity but also providing a suitable niche to model lung endothelium responses to injury ex vivo. [ABSTRACT FROM AUTHOR]

Agriculture dust contains many organic immunogenic compounds, and organic dust exposure is strongly associated with the development of immune-mediated chronic pulmonary diseases such as chronic obstructive pulmonary disease (COPD). Chronic organic dust exposure from agriculture sources induces chronic lung inflammatory diseases and organic dust exposure has recently been linked to an increased risk of developing dementia. The cytokine interleukin-22 (IL-22) has been established as an important mediator in the resolution and repair of lung tissues. The omega-3 fatty acid metabolite aspirin-triggered Resolvin D1 (AT-RvD1) has shown efficacy in modulating the immune response in both pulmonary and neurological inflammation but has not been explored as a therapeutic in organic dust exposure-induced neuroinflammation. Investigating the link between IL-22 and AT-RvD1 may help in developing effective therapies for these immune-mediated diseases. We aimed to investigate the link between organic dust exposure and neuroinflammation, the role of IL-22 in the pulmonary and neurological immune response to organic dust exposure, and the immune-modulating therapeutic applications of AT-RvD1 in an IL-22 knock-out mouse model of organic dust exposure. C57BL/6J (WT) and IL-22 knock-out (KO) mice were repetitively exposed to aqueous agriculture organic dust extract (DE) 5 days per week for 3 weeks (15 total instillations) and treated with AT-RvD1 either once per week (3 total injections) or 5 times per week (15 total injections) for 3 weeks and allowed to recover for 3 days. We observed a significant pulmonary and neurological immune response to DE characterized by the development of inducible bronchus associated lymphoid tissue in the lung and gliosis in the frontal areas of the brain. We also observed that IL-22 knock-out increased pulmonary and neurological inflammation severity. Animals exposed to DE and treated with AT-RvD1 displayed reduced lung pathology severity and gliosis. Our data demonstrate that DE exposure contributes to neurological inflammation and that IL-22 is crucial to effective tissue repair processes. Our data further suggest that AT-RvD1 may have potential as a novel therapeutic for organic dust exposure-induced, immune-mediated pulmonary and neurological inflammation, improving outcomes of those with these diseases. [ABSTRACT FROM AUTHOR]

Objective To study the protective effect of melatonin on PM2.5-induced inflammation and lymphangiogenesis in the lung of ApoE-/- mice. Methods Twenty-eight male ApoE-/- mice were randomized into # control group, PM2.5 group, melatonin group and PM2.5 + melatonin group. All mice were fed with western diet for 24 weeks. From the 25th week, mice in the melatonin group and PM2.5 + melatonin group were daily orally gavage with melatonin (20 mg/kg • bw) for 8 weeks; mice in the PM2.5 group and PM2.5 + melatonin group were exposed to PM2.5 by tracheal instillation (5mg/kg); and mice in the control group and melatonin group were instilled with saline at the same time. After 24 h of PM2.5 exposure, mice were euthanized and weight gain and lung weight/body weight ratio in four groups were analyzed. The concentrations of inflammatory cytokines (TNF - α and IL-6) in the lung tissue of mice were measured. Immunofluorescence staining of lung tissue was visualized the lymphatic marker LYVE1 expression. Western Blot was used to assess the protein expression levels of lymphangiogenesis markers PROX1 and LYVE1, lymphangiogenesis regulatory proteins VEGF-C and VEGFR-3 in lung tissues. Results The levels of TNF-α and IL-6 and the protein expressions of PROX1, LYVE1, VEGF-C and VEGFR-3 in lung tissues of PM2.5 group were significantly higher than the control group (P < 0.05). Moreover, the levels of TNF-α, IL-6 and the protein expressions of PROX1, LYVE1, VEGF-C and VEGFR-3 in lung tissues of the PM2.5 + melatonin group were significantly lower than the PM2.5 group (P < 0.05). Conclusion Ambient PM2. 5 exposure obviously increases lung inflammation of ApoE-/- mice, and may increase lymphangiogenesis in lung through regulating the VEGF-C/VEGFR-3 signaling pathway in the lung tissues; melatonin markedly improves PM2.5-induced lung inflammation and reduces lymphangiogenesis in lung. [ABSTRACT FROM AUTHOR]

Lung inflammation is a hallmark of several respiratory diseases. Despite the great effectiveness of the synthetic antiinflammatory agents, they cause potential side effects. Polydatin (PD), a natural phytomedicine, has antioxidant and antiinflammatory effects. Its clinical applications are hindered due to poor aqueous solubility, low bioavailability, and rapid metabolism by first-pass effect. Herein, we report the development of a novel chitosan oligosaccharide-coated PD-loaded Poly dl-lactide-co-glycolide nanoparticles (COS-coated PD/PLGA NPs) against a bleomycin-induced pulmonary inflammation in a rat model. The NPs exhibited a small particle size of 188.57 ± 5.68 nm and a high zeta potential of + 18.13 ± 2.75 mV with spherical architecture and sustained release pattern of PD. In vivo studies in bleomycin-induced lung inflammation in a rat model revealed the superior prophylactic activity of COS-coated PD/PLGA NPs over the free drug (PD) as demonstrated by histopathological and immunohistochemical analyses, alongside biochemical assays evaluating oxidative stress biomarkers and inflammatory cytokine levels. Overall, the optimized COS-coated PD/PLGA NPs formulation offers a promising prophylactic platform against many respiratory diseases. [ABSTRACT FROM AUTHOR]

Abstract While Th2 adaptive immunity has long been considered to orchestrate type 2 inflammation in the allergic lung, group 2 innate lymphoid cells (ILC2s), with the ability to produce a similar profile of type 2 cytokines, likely participate in lung inflammation in allergic asthma. ILC2s are also implicated in sex disparities in asthma, supported by data from murine models showing they are inhibited by male sex hormones. Moreover, larger numbers of ILC2s are present in the lungs of female mice and are correlated with greater type 2 inflammation. Lung ILC2s exhibit intriguing memory-like responses, though whether these differ in males and females does not appear to have been addressed. We have examined type 2 lung inflammation in adult male and female Balb/c mice following delivery of IL-33 to the lung. While the number of ILC2s was elevated equally in males and females four weeks after exposure to IL-33, ILC2s from female mice expressed higher levels of ST2, the IL-33 cognate receptor subunit, and a larger proportion of ILC2s from females expressed the IL-25 receptor (IL-25R), which has previously been linked to memory-like ILC2 responses in mice. Our data show that the subset of ILC2s expressing IL-25R, upon activation, was more likely to produce IL-5 and IL-13. Moreover, STAT6 was absolutely required for enhanced responsiveness in this model system. Altogether, our data show that enhanced type 2 inflammation in females is linked to durable changes in ILC2 subsets with the ability to respond more robustly, in a STAT6-dependent manner, upon secondary activation by innate epithelial-derived cytokines.

Abstract Background Respirable mineral particles can induce lower airway inflammation, but the role they play in asthma of horses is unknown. Objectives Respirable mineral particles, particularly respirable silica, are an overlooked determinant of chronic lung inflammation (asthma) in horses. Animals Twenty‐three horses from an equine hospital population: 11 moderately affected (MEA), 7 severely asthmatic (SEA), and 5 control horses free from respiratory clinical signs. Methods Prospective observational study. The quantity and quality of mineral particles found in bronchoalveolar lavage fluid (BALF) were characterized, with particular attention to silica content. Polarized light microscopy performed on cytospin slides identified intracellular birefringent particles as silica. Spectrometry‐based analysis performed on whole BALF determined total mineral and silica percentage and concentration. Group‐related differences in BALF mineral and silica load were investigated as well as associations with BALF cytology. Results Intracellular birefringent particles were increased in SEA vs MEA (median [interquartile range, IQR]), 12 [7] vs 4 [5] particles/30 high power fields [hpf], respectively; P = .01) and vs controls (4 [2] particles/30 hpf; P = .02). Total mineral concentration in BALF was similar between the groups studied, whereas silica concentration and percentage were increased in SEA vs MEA (1758 [887] particles/mL and 20 [10]% vs 867 [662] particles/mL and 8 [6]%; P = .009 and P = .001) and control group (355 [330] particles/mL and 6 [3]%; P = .0003 and P = .002). Silica load in BALF was associated with BALF neutrophilia in MEA and SEA. Conclusions and Clinical Importance Respirable silica is associated with neutrophilic lower airway inflammation in horses and might contribute to asthma development.

Hui Xu,1,2 Xin Li,1 Kai Liu,1 Ping Huang,1 Xiao-Ju Liu1,2 1The First School of Clinical Medicine, Lanzhou University, Lanzhou, Gansu, People’s Republic of China; 2The First Hospital of Lanzhou University, Lanzhou, Gansu, People’s Republic of ChinaCorrespondence: Xiao-Ju Liu, Email liuxiaoju835@126.comBackground: Airway epithelial cells (AECs) and alveolar macrophages are involved in airway inflammation. The direct effects of atmospheric fine-particulate-matter (PM2.5) on airway cells, such as AECs and alveolar macrophages, have been widely investigated, but the effect of cell-cell interaction on inflammatory response remains unclear. Exosomes play a crucial role in intercellular communication. However, the cellular interaction of exosomes in PM2.5-induced airway inflammation is unclear.Methods: The PM2.5-induced human bronchial epithelial (BEAS-2B) cells and phorbol 12-myristate 13-acetate-induced macrophages (M&phis;) were co-cultured and then the expression of IL-6, IL-1β, TNF-α and miRNA-155-5p were detected. Exosomes from PM2.5-exposed BEAS-2B cells were then co-cultured with M&phis; to detect the expression of miR-155-5p and inflammatory cytokines, as well as cytokine signaling inhibitor-1 (SOCS1)/NFκB, and to detect the effect of the exosome inhibitor GW4869.Results: After the co-culture of PM2.5-induced BEAS-2B cells and M&phis;, the expression of M&phis;-derived IL-6, IL-1β, and TNF-α, as well as miRNA-155-5p were upregulated. The expression of miRNA-155-5p was upregulated in BEAS-2B and BEAS-2B cell-derived exosomes after exposure to PM2.5. Furthermore, co-culturing exosomes derived from PM2.5-exposed BEAS-2B cells with M&phis;, upregulated miR-155-5p and inflammatory cytokines, decreased cytokine signaling inhibitor-1 (SOCS1) expression, and activated NF-κB. In addition, adding exosome inhibitor GW4869 to PM2.5-interfered BEAS-2B cells co-culture with M&phis; downregulated miRNA-155-5p expression, inhibited NF-κB, and reduced the levels of inflammatory factors.Conclusion: PM2.5 promotes M&phis; inflammation by upregulating miRNA-155-5P in exosomes obtained from BEAS-2B cells through miR-155-5P/SOCS1/NF-κB pathway. Exosomal miRNAs mediate cellular communication between BEAS-2B cells and M&phis;, which may be a new mechanism of PM2.5-stimulated pulmonary inflammatory response. Keywords: PM2.5, exosome, microRNA, lung inflammation

Agriculture dust contains many organic immunogenic compounds, and organic dust exposure is strongly associated with the development of immune-mediated chronic pulmonary diseases such as chronic obstructive pulmonary disease (COPD). Chronic organic dust exposure from agriculture sources induces chronic lung inflammatory diseases and organic dust exposure has recently been linked to an increased risk of developing dementia. The cytokine interleukin-22 (IL-22) has been established as an important mediator in the resolution and repair of lung tissues. The omega-3 fatty acid metabolite aspirin-triggered Resolvin D1 (AT-RvD1) has shown efficacy in modulating the immune response in both pulmonary and neurological inflammation but has not been explored as a therapeutic in organic dust exposure-induced neuroinflammation. Investigating the link between IL-22 and AT-RvD1 may help in developing effective therapies for these immune-mediated diseases. We aimed to investigate the link between organic dust exposure and neuroinflammation, the role of IL-22 in the pulmonary and neurological immune response to organic dust exposure, and the immune-modulating therapeutic applications of AT-RvD1 in an IL-22 knock-out mouse model of organic dust exposure. C57BL/6J (WT) and IL-22 knock-out (KO) mice were repetitively exposed to aqueous agriculture organic dust extract (DE) 5 days per week for 3 weeks (15 total instillations) and treated with AT-RvD1 either once per week (3 total injections) or 5 times per week (15 total injections) for 3 weeks and allowed to recover for 3 days. We observed a significant pulmonary and neurological immune response to DE characterized by the development of inducible bronchus associated lymphoid tissue in the lung and gliosis in the frontal areas of the brain. We also observed that IL-22 knock-out increased pulmonary and neurological inflammation severity. Animals exposed to DE and treated with AT-RvD1 displayed reduced lung pathology severity and gliosis. Our data demonstrate that DE exposure contributes to neurological inflammation and that IL-22 is crucial to effective tissue repair processes. Our data further suggest that AT-RvD1 may have potential as a novel therapeutic for organic dust exposure-induced, immune-mediated pulmonary and neurological inflammation, improving outcomes of those with these diseases. [ABSTRACT FROM AUTHOR]

Background: The tracheobronchial and oral microbiome may be associated with lung cancer, potentially acting as predictive biomarkers. Therefore, we studied the lung and oral bacteriome and virome in non-small cell lung cancer (NSCLC) patients compared to melanoma controls to discover distinguishable features that may suggest lung cancer microbial biomarkers. Methods: In this pilot case-control study, we recruited ten patients with early-stage NSCLC (cases) and ten age-matched melanoma patients (controls) who both underwent tumor resection. Preoperative oral gargles were collected from both groups, who then underwent transbronchoscopic tracheal lavage after intubation. Lung tumor and adjacent non-neoplastic lung were sterilely collected after resection. Microbial DNA from all lung specimens underwent 16S rRNA gene sequencing. Lavage and gargle specimens underwent whole-genome shotgun sequencing. Microbiome metrics were calculated to compare both cohorts. T-tests and Wilcoxon rank sum tests were used to test for significant differences in alpha diversity between cohorts. PERMANOVA was used to compare beta diversity. Results: No clear differences were found in the microbial community structure of case and control gargles, but beta diversity of case and control lavages significantly differed. Two species, Granulicatella adiacens and Neisseria subflava , which are both common oral commensal organisms, appeared in much higher abundance in case versus control lavages. Case lavages also maintained higher relative abundances of other oral commensals compared to controls. Conclusions: Lung lavages demonstrated oral microbiota enrichment in cases compared to controls, suggesting microaspiration and resultant inflammation. The oral commensals Granulicatella adiacens and Neisseria subflava were more abundant in the tracheobronchial lavages of lung cancer versus melanoma patients, implicating these microorganisms as potential lung cancer biomarkers, warranting further validation studies. [ABSTRACT FROM AUTHOR]

While Th2 adaptive immunity has long been considered to orchestrate type 2 inflammation in the allergic lung, group 2 innate lymphoid cells (ILC2s), with the ability to produce a similar profile of type 2 cytokines, likely participate in lung inflammation in allergic asthma. ILC2s are also implicated in sex disparities in asthma, supported by data from murine models showing they are inhibited by male sex hormones. Moreover, larger numbers of ILC2s are present in the lungs of female mice and are correlated with greater type 2 inflammation. Lung ILC2s exhibit intriguing memory-like responses, though whether these differ in males and females does not appear to have been addressed. We have examined type 2 lung inflammation in adult male and female Balb/c mice following delivery of IL-33 to the lung. While the number of ILC2s was elevated equally in males and females four weeks after exposure to IL-33, ILC2s from female mice expressed higher levels of ST2, the IL-33 cognate receptor subunit, and a larger proportion of ILC2s from females expressed the IL-25 receptor (IL-25R), which has previously been linked to memory-like ILC2 responses in mice. Our data show that the subset of ILC2s expressing IL-25R, upon activation, was more likely to produce IL-5 and IL-13. Moreover, STAT6 was absolutely required for enhanced responsiveness in this model system. Altogether, our data show that enhanced type 2 inflammation in females is linked to durable changes in ILC2 subsets with the ability to respond more robustly, in a STAT6-dependent manner, upon secondary activation by innate epithelial-derived cytokines. [ABSTRACT FROM AUTHOR]

NRF2 is a nuclear transcription factor involved in the cellular protection against oxidative stress and inflammatory signaling. Sulforaphane is a known NRF2 activator used for its strong antioxidant and anti‐inflammatory activity through regulation of Keap‐1‐HO‐1 pathway. However, there is a limited exploration about the role of NRF2 activator, sulforaphane in regulation of poly(I:C)‐induced oxidative stress, inflammation and injury in lung. Therefore, we aimed to evaluate the therapeutic effect of sulforaphane in poly(I:C)‐induced responses using in vitro as well as in vivo model. We evaluated oxidative stress and inflammatory cytokines in poly(I:C)‐induced RAW264.7 cells. We also employed in vivo animal study to evaluate tissue oxidative–antioxidative balance along with expression of NRF2, Keap‐1, histopathological assessment by hematoxylin–eosin staining and picrosirius red staining to explore the protective mechanisms of sulforaphane in poly(I:C)‐induced mouse model. Our results indicated that sulforaphane increased the expression of NRF2 and its downstream proteins. In addition, sulforaphane alleviated poly(I:C)‐induced activation of the oxidative and pro‐inflammatory pathways, histopathological changes, depleted expression of GSH and superoxide dismutase in lung tissue. This study suggested that sulforaphane may be one of the useful therapeutic alternatives for poly(I:C) induced lung injury and inflammation. [ABSTRACT FROM AUTHOR]

Fine particulate matter (PM) 2.5 contains metals, ions, and carbon compounds, varying dynamically due to environmental factors. This study identified five major metals (Ca, Fe, Al, Zn and Pb) in urban PM2.5 via meta-analysis and evaluated their hazardous effects on health. Mice were exposed to these metals through intratracheal instillation, revealing changes in white blood cell count and serum substances (bilirubin, BUN and LDH), along with lung inflammation. Increased levels of proinflammatory cytokines (IL-1b, IL-6 and TNF-α) were observed, indicating adverse effects on the respiratory system. These results suggest that further studies on the health effects of the major metals of PM2.5, development of indicators for determining the PM2.5 exposure levels, and methods for reducing the metals together with other components in PM2.5 are needed. [ABSTRACT FROM AUTHOR]

Background and Purpose: Toll‐like receptors 4 (TLR4) and TLR7/TLR8 play an important role in mediating the inflammatory effects of bacterial and viral pathogens. Interleukin‐1 receptor‐associated kinase 4 (IRAK4) is an important regulator of signalling by toll‐like receptor (TLR) and hence is a potential therapeutic target in diseases characterized by increased lung inflammatory signalling. Experimental Approach: We used an established murine model of acute lung inflammation, and studied human lung tissue ex vivo, to investigate the effects of inhibiting IRAK4 on lung inflammatory pathways. Key Results: We show that TLR4 stimulation produces an inflammatory response characterized by neutrophil influx and tumour necrosis factor‐α (TNF‐α) production in murine lungs and that these responses are markedly reduced in IRAK4 kinase‐dead mice. In addition, we characterize a novel selective IRAK4 inhibitor, BI1543673, and show that this compound can reduce lipopolysaccharide (LPS)‐induced airway inflammation in wild‐type mice. Additionally, BI1543673 reduced inflammatory responses to both TLR4 and TLR7/8 stimulation in human lung tissue studied ex vivo. Conclusion and Implications: These data demonstrate a key role for IRAK4 signalling in lung inflammation and suggest that IRAK4 inhibition has potential utility to treat lung diseases characterized by inflammatory responses driven through TLR4 and TLR7/8. [ABSTRACT FROM AUTHOR]

Background. Lipid–polymer hybrid nanoparticles (LPHNPs) offer a promising method for delivering methylprednisolone (MePD) to treat lung inflammation, addressing aggregation issues seen with polymer-only formulations. Objectives. This study aimed to develop LPHNPs for MePD delivery, assessing their physicochemical properties, drug loading, cytocompatibility, and release profiles, ultimately enabling inhalable microparticle-based powder. Methods. The nanoparticles were formulated using α,β-poly(N-2-hydroxyethyl)-DL-aspartamide-g-Rhodamine B-g-poly(lactic acid) (PHEA-g-RhB-g-PLA) and phospholipids DPPC, DOTAP, and DSPE-PEG2000 in a 45:30:25 weight ratio. Their size, redispersion after freeze-drying, drug loading (DL%), and controlled release were evaluated. Cytocompatibility was assessed on 16-HBE cell lines, measuring anti-inflammatory effects via IL-6 and IL-8 levels. Spray drying was optimized to produce microparticles using mannitol (MAN), leucine (LEU), and N-acetylcysteine (NAC). Results. The nanoparticles had a size of 186 nm and a DL% of 2.9% for MePD. They showed good cytocompatibility, significantly reducing IL-6 and IL-8 levels. Spray drying yielded microparticles with a fine particle fraction (FPF) of 62.3% and a mass median aerodynamic diameter (MMAD) of 3.9 µm. Inclusion of LPHNPs@MePD (0.25% w/v) resulted in FPF and MMAD values of 56.7% and 4.4 µm. In conclusion, this study described the production of novel inhalable powders as carriers for MePD-loaded nanostructures with favorable physicochemical properties, cytocompatibility, and promising aerosol performance, indicating their potential as an effective inhalable therapy for lung inflammation with corticosteroids, especially for treating chronic diseases. [ABSTRACT FROM AUTHOR]

Idiopathic pulmonary fibrosis (IPF) is the most common and severe form of pulmonary fibrosis, characterized by scar formation in the lung interstitium. Transforming growth factor beta (TGF-b) is known as a key mediator in the fibrotic process, acting on fibroblasts and mediating their proliferation and differentiation into myofibroblasts. Although the immune system is not considered responsible for the initiation of IPF, markers of tolerogenic immunity define the pro-fibrotic microenvironment in the lungs. In homeostatic conditions, regulatory T cells (Tregs) constitute the main lymphoid population responsible for maintaining peripheral tolerance. Similar to Tregs, regulatory B cells (Bregs) represent a recently described subset of B lymphocytes with immunosuppressive functions. In the context of IPF, numerous studies have suggested a role for Tregs in enhancing fibrosis, mainly via the secretion of TGF-b. In humans, most studies show increased percentages of Tregs associated with the severity of IPF, although their exact role remains unclear. In mice, the most commonly used model involves triggering acute lung inflammation with bleomycin, leading to a subsequent fibrotic process. Consequently, data are still conflicting, as Tregs may play a protective role during the inflammatory phase and a deleterious role during the fibrotic phase. Bregs have been less studied in the context of IPF, but their role appears to be protective in experimental models of lung fibrosis. This review presents the latest updates on studies exploring the implication of regulatory lymphoid cells in IPF and compares the different approaches to better understand the origins of conflicting findings. [ABSTRACT FROM AUTHOR]

Background: Respirable mineral particles can induce lower airway inflammation, but the role they play in asthma of horses is unknown. Objectives: Respirable mineral particles, particularly respirable silica, are an overlooked determinant of chronic lung inflammation (asthma) in horses. Animals: Twenty‐three horses from an equine hospital population: 11 moderately affected (MEA), 7 severely asthmatic (SEA), and 5 control horses free from respiratory clinical signs. Methods: Prospective observational study. The quantity and quality of mineral particles found in bronchoalveolar lavage fluid (BALF) were characterized, with particular attention to silica content. Polarized light microscopy performed on cytospin slides identified intracellular birefringent particles as silica. Spectrometry‐based analysis performed on whole BALF determined total mineral and silica percentage and concentration. Group‐related differences in BALF mineral and silica load were investigated as well as associations with BALF cytology. Results: Intracellular birefringent particles were increased in SEA vs MEA (median [interquartile range, IQR]), 12 [7] vs 4 [5] particles/30 high power fields [hpf], respectively; P =.01) and vs controls (4 [2] particles/30 hpf; P =.02). Total mineral concentration in BALF was similar between the groups studied, whereas silica concentration and percentage were increased in SEA vs MEA (1758 [887] particles/mL and 20 [10]% vs 867 [662] particles/mL and 8 [6]%; P =.009 and P =.001) and control group (355 [330] particles/mL and 6 [3]%; P =.0003 and P =.002). Silica load in BALF was associated with BALF neutrophilia in MEA and SEA. Conclusions and Clinical Importance: Respirable silica is associated with neutrophilic lower airway inflammation in horses and might contribute to asthma development. [ABSTRACT FROM AUTHOR]

Purpose: Amniotic fluid stem cell extracellular vesicles (AFSC-EVs) hold regenerative potential to treat hypoplastic lungs secondary to congenital diaphragmatic hernia (CDH). This study aims to investigate sex-specific differences in pulmonary hypoplasia severity and responses to AFSC-EV administration in an experimental CDH mouse model. Methods: C57BL/6J dams were fed with nitrofen + bisdiamine (left-sided CDH) or olive oil only (control) at embryonic day (E) 8.5. Lungs were dissected (E18.5), grown ex vivo and treated with medium ± AFSC-EVs that were collected via ultracentrifugation and characterized (nanoparticle tracking analysis, electron microscopy, Western blotting). Pulmonary hypoplasia was assessed via mean linear intercept (MLI). Gene and protein expression changes (Cd31, Enos, Il1b, TNFa) were measured via RT-qPCR and immunofluorescence. Pups were genotyped for Sry. Results: Experimental CDH showed a male predominance without sex differences for pulmonary hypoplasia severity, fetal lung vascularization, and inflammation. AFSC-EV administration led to improved lung growth (decreased MLI), improved fetal lung vascularization (increased Cd31 and Enos), and decreased fetal lung inflammation (Il1b, TNFa). There was no sex-specific response to AFSC-EV administration. Conclusion: This study shows sex-independent impaired lung growth, vascularization and fetal lung inflammation in a CDH mouse model. Antenatal administration of AFSC-EVs reverses aspects of pulmonary hypoplasia secondary to CDH independent of the biological sex. [ABSTRACT FROM AUTHOR]

Background Aim Methods Results Conclusions Air pollutants, such as diesel exhaust particles (DEPs), induce respiratory disease exacerbation with neutrophilic infiltration. Progranulin (PGRN), an epithelial cell and macrophage‐derived secretory protein, is associated with neutrophilic inflammation. PGRN is digested into various derivatives at inflammatory sites and is involved in several inflammatory processes. PGRN and its derivatives likely regulate responses to DEP exposure in allergic airway inflammation.To investigate the role of PGRN and its derivatives in the regulation of responses to DEP exposure in allergic airway inflammation.A murine model of allergic airway inflammation was generated in PGRN‐deficient mice, and they were simultaneously exposed to DEP followed by intranasal administration of full‐length recombinant PGRN (PGRN‐FL) and a PGRN‐derived fragment (FBAC). Inflammatory status was evaluated by bronchoalveolar lavage fluid and histopathologic analyses. Human bronchial epithelial cells were stimulated with DEPs and house dust mites (HDMs), and the effect of FBAC treatment was evaluated by assessing various intracellular signaling molecules, autophagy markers, inflammatory cytokines, and intracellular oxidative stress.DEP exposure exaggerated neutrophilic inflammation, enhanced IL‐6 and CXCL15 secretions, and increased oxidative stress in the murine model; this effect was greater in PGRN‐deficient mice than in wild‐type mice. The DEP‐exposed mice with PGRN‐FL treatment revealed no change in neutrophil infiltration and higher oxidative stress status in the lungs. On the contrary, FBAC administration inhibited neutrophilic infiltration and reduced oxidative stress. In human bronchial epithelial cells, DEP and HDM exposure increased intracellular oxidative stress and IL‐6 and IL‐8 secretion. Decreased nuclear factor erythroid 2‐related factor 2 (Nrf2) expression and increased phosphor‐p62 and LC3B expression were also observed. FBAC treatment attenuated oxidative stress from DEP and HDM exposure.FBAC reduced neutrophilic inflammation exaggerated by DEP exposure in a mouse model of allergic airway inflammation by reducing oxidative stress. PGRN and PGRN‐derived proteins may be novel therapeutic agents in attenuating asthma exacerbation induced by air pollutant exposure. [ABSTRACT FROM AUTHOR]

Type III interferons (λ1, λ2, and λ3) are potent antiviral cytokines in the lung. However, their roles in nonviral lung injuries are less well understood. This study investigates the activation of type III interferon signaling in three distinct models of lung injuries caused by diverse stimuli: the bacterial pathogen Pseudomonas aeruginosa, bacterial endotoxin LPS, and the chemotherapeutic agent bleomycin. Our data show that, despite inducing a potent inflammatory response, Pseudomonas and LPS did not increase IFNλ secretion. In contrast, bleomycin instillation increased secretion of IFNλ in the airways at both early and late time points. Consistent with limited secretion, type III interferon signaling had a minimal role in the host response to both Pseudomonas and LPS, as measured by pathogen burden, inflammatory response, and lung injury. Conversely, a deficiency in type III interferon signaling led to increased inflammatory signaling and elevated acute lung injury in the bleomycin model on day 3. This elevated early injury resulted in impaired recovery in IFNLR1 knockout mice, as evidenced by their recovery from bleomycin‐induced weight loss. Taken together, these data suggest a context‐specific activation of type III interferon signaling, where it plays an anti‐inflammatory role in the lung. [ABSTRACT FROM AUTHOR]

Gut microbiota is an intricate microbial community containing bacteria, fungi, viruses, archaea, and protozoa, and each of them contributes to diverse aspects of host health. Nevertheless, the influence of interaction among gut microbiota on host health remains uncovered. Here, we showed that the interaction between intestinal fungi and bacteria shaped lung inflammation during infection. Specifically, antifungal drug‐induced dysbiosis of gut mycobiota enhanced lung inflammation during infection. Dysbiosis of gut mycobiota led to gut Escherichia coli (E. coli) overgrowth and translocation to the lung during infection, which induced lung accumulation of the CD45+F4/80+Ly6G−Ly6C−CD11b+CD11c+ macrophages. Clearance of macrophages or deletion of TLR4 (Toll‐like receptor 4, recognition of LPS) rather than Dectin‐1 (recognition of beta‐1,3/1,6 glucans on fungi) blocked the antifungal drug‐induced aggravation of lung inflammation during infection. These findings suggest that the interaction between intestinal mycobiota and commensal bacteria affects host health through the gut–lung axis, offering a potential therapeutic target for ameliorating lung inflammation during infection. Highlights: Antifungal drug‐induced dysbiosis of gut mycobiota aggravates lung inflammation during infection.Dysbiosis of intestinal mycobiota results in gut Escherichia coli overgrowth and translocation to the lung during infection.E. coli induces lung accumulation of the CD45+F4/80+Ly6G−Ly6C−CD11b+CD11c+ macrophages.Clearance of macrophages or deletion of TLR4 blocks the antifungal drug‐induced aggravation of lung inflammation during infection. [ABSTRACT FROM AUTHOR]

Regnase-1 is an RNase that plays a critical role in negatively regulating immune responses by destabilizing inflammatory messenger RNAs (mRNAs). Dysfunction of Regnase-1 can be a major cause of various inflammatory diseases with tissue injury and immune cell infiltration into organs. This study focuses on the role of the RNase activity of Regnase-1 in developing inflammatory diseases. We have constructed mice with a single point mutation at the catalytic center of the Regnase-1 RNase domain, which lacks endonuclease activity. D141N mutant mice demonstrated systemic inflammation, immune cell infiltration into various organs, and progressive development of lung granuloma. CD4+ T cells, mainly affected by this mutation, upregulated the mTORC1 pathway and facilitated the autoimmune trait in the D141N mutation. Moreover, serine/threonine kinase Pim2 contributed to lung inflammation in this mutation. Inhibition of Pim2 kinase activity ameliorated granulomatous inflammation, immune cell infiltration, and proliferation in the lungs. Additionally, Pim2 inhibition reduced the expression of adhesion molecules on CD4+ T cells, suggesting a role for Pim2 in facilitating leukocyte adhesion and migration to inflamed tissues. Our findings provide new insights into the role of Regnase-1 RNase activity in controlling immune functions and underscore the therapeutic relevance of targeting Pim2 to modulate abnormal immune responses. [ABSTRACT FROM AUTHOR]

Tertiary lymphoid structures (TLS) resemble follicles of secondary lymphoid organs and develop in nonlymphoid tissues during inflammation and cancer. Which cell types and signals drive the development of TLS is largely unknown. To investigate early events of TLS development in the lungs, we repeatedly instilled p(I:C) plus ovalbumin (Ova) intranasally. This induced TLS ranging from lymphocytic aggregates to organized and functional structures containing germinal centers. We found that TLS development is independent of FAP+ fibroblasts, alveolar macrophages, or CCL19 but crucially depends on type I interferon (IFN‐I). Mechanistically, IFN‐I initiates two synergistic pathways that culminate in the development of TLS. On the one hand, IFN‐I induces lymphotoxin (LT)α in lymphoid cells, which stimulate stromal cells to produce the B‐cell‐attracting chemokine CXCL13 through LTβR‐signaling. On the other hand, IFN‐I is sensed by stromal cells that produce the T‐cell‐attracting chemokines CXCL9, CXCL10 as well as CCL19 and CCL21 independently of LTβR. Consequently, B‐cell aggregates develop within a week, whereas follicular dendritic cells and germinal centers appear after 3 weeks. Thus, sustained production of IFN‐I together with an antigen is essential for the induction of functional TLS in the lungs. [ABSTRACT FROM AUTHOR]

Inflammation is an essential factor in pulmonary complications of diabetes. Bone marrow (BM)-derived C-kit+ cells have immunomodulatory properties and their transplantation is suggested as a promising strategy for ameliorating diabetes complications. This study evaluated the effect of BM-derived C-kit+ cells on the inflammation signaling pathway in lung tissue of type 2 diabetic male rats. Ten rats were used to extract C-kit cells, and 48 male Wistar rats weighing 180 ± 20 g were randomly divided into four equal groups: (1) Control (Cont), (2) Diabetic (D), (3) Diabetic + C-kit+ cells (D + C-kit pos) intravenously injected 50-µl phosphate buffer saline (PBS) containing 300,000 C-kit+ cells, and (4) Diabetic + C-kit− cells (D + C-kit neg), intravenously injected C-kit− cells. Diabetes induction increased IL-33, ST-2, CD127, and IL-2 levels and decreased IL-10. C-kit+ cell therapy significantly decreased IL-33 and CD127 and increased IL-10. In addition, lung histopathological changes significantly improved in the C-kit+ group compared to the diabetic group. These findings suggest that C-kit+ cells may have a potential therapeutic role in mitigating diabetes-induced respiratory complications via ameliorating the inflammation and histopathological changes in lung tissue. [ABSTRACT FROM AUTHOR]

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are severe clinical disorders that mainly develop from viral respiratory infections, sepsis, and chest injury. Antigen-presenting cells play a pivotal role in propagating uncontrolled inflammation and injury through the excess secretion of pro-inflammatory cytokines and recruitment of immune cells. Autophagy, a homeostatic process that involves the degradation of cellular components, is involved in many processes including lung inflammation. Here, we use a polyinosinic-polycytidylic acid (poly(I:C))-induced lung injury mouse model to mimic viral-induced ALI/ARDS and show that disruption of autophagy in macrophages exacerbates lung inflammation and injury, whereas autophagy induction attenuates this process. Therefore, induction of autophagy in macrophages can be a promising therapeutic strategy in ALI/ARDS.

Innate lymphoid cells (ILCs) are a rare cell population subdivided into ILC1s, ILC2s, and ILC3s, based on transcription factor expression and cytokine production. In models of lung inflammation, the release of alarmins from the epithelium activates ILC2s and promotes the production of Th2-cytokines and the proliferation and migration of ILC2s within the lung. ILC2s are the innate counterpart to CD4+ Th2s and, as such, express Gata-3 and produce IL-4, IL-5, and IL-13. Due to the low number of ILCs and the lack of specific surface markers, flow cytometry is the most reliable technique for the identification and characterization of ILCs. In this protocol, multicolor flow cytometry is utilized to identify Lineage- Thy1.2+ ILCs. Intracellular cytokine staining further identifies ILC2s within the lung. This protocol presents a reliable method for promoting ILC2-mediated lung inflammation and for monitoring ILC2 biology. Key features In this protocol, ILC2s are expanded via intranasal challenges withAlternaria alternata, a fungal allergen, or recombinant IL-33. Bronchoalveolar lavage (BAL) and lung are collected and processed into single-cell suspension for multicolor flow cytometric analysis, including intracellular staining of transcription factors and cytokines. During lung inflammation, the percentage of ILC2s and eosinophils increases. ILC2s express greater levels ofGata-3andKi-67and produce greater amounts of IL-5 and IL-13. Graphical overview.

Acute respiratory distress syndrome (ARDS), a severe form of acute lung injury (ALI), is the major cause of intensive care unit death worldwide. ALI/ARDS is a common condition characterized by a storm of potent inflammatory cytokines. Lung delivery of glucocorticoids (GCs) by inhalation is a potential approach for ALI treatment and ARDS prevention; however, its efficacy is limited by the rapid clearance of GCs in lungs. In this study, we developed surface-modified poly(lactic acid)-hyperbranched polyglycerol nanoparticles (BNPs) with bioadhesive properties for local delivery to the epidermis of lung tissues, which exhibited prolonged release profile of payloads following intratracheal spraying administration. Compared with that of non-adhesive nanoparticles (NNPs), BNPs showed significantly enhanced adhesion and prolonged retention within lung tissues in vivo. Lipopolysaccharide (LPS)-induced ALI mice treated with betamethasone dipropionate (BD)-loaded BNPs showed significantly fewer lung histological alterations and less lung inflammation than those administered free BD or BD-loaded NNPs, indicating the enhanced therapeutic efficacy of BD/BNPs in ALI. In contrast, the features of ARDS were observed in the animal models without any treatments. Our findings demonstrated that pulmonary delivery of BNPs can maintain their same surface structures and continuously form covalent connections with the contacted tissues, emphasizing their potential to improve the therapeutic efficacy in ALI and prevent from ARDS.

Haidong He,1 Shuihua Sun,2 Weihua Xu,1 Mingwan Zhang3 1Department of Pulmonary and Critical Care Medicine, Tongde Hospital of Zhejiang Province, Hangzhou City, Zhejiang Province, People’s Republic of China; 2Department of Medical Oncology, Tongde Hospital of Zhejiang Province, Hangzhou City, Zhejiang Province, People’s Republic of China; 3Department of Pharmacy, Tongde Hospital of Zhejiang Province, Hangzhou City, Zhejiang Province, People’s Republic of ChinaCorrespondence: Haidong He, Department of Pulmonary and Critical Care Medicine, Tongde Hospital of Zhejiang Province, 234 Gucui Road, Cuiyuan Street, Xihu District, Hangzhou City, Zhejiang Province, 310012, People’s Republic of China, Tel +86-571-89972427, Email hhd0901190040@163.comPurpose: Sangbaipi decoction (SBPD), a traditional Chinese medicine (TCM) prescription, has been widely used to treat acute exacerbation of chronic obstructive pulmonary disease (AECOPD), while the underlying pharmacological mechanism remains unclear due to the complexity of composition.Methods: A TCM-active ingredient-drug target network of SBPD was constructed utilizing the TCM-Systems-Pharmacology database. AECOPD-relevant proteins were gathered from Gene Cards and the Online-Mendelian-Inheritance-in-Man database. Protein–protein interaction, GO and KEGG enrichment analyses of the targets from the intersection of SBPD and AECOPD targets were performed to identify the core signaling pathway, followed by molecular docking verification of its interaction with active ingredients. The network pharmacology results were checked using in-vivo experiments. To induce AECOPD, rats were exposure to combined tobacco smoke and lipopolysaccharide (LPS). Then rats underwent gavage with stigmasterol (SM) after successful modeling. The involvement of phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) signaling was investigated using its inhibitor, LY294002. Lung function and histopathology were examined. The levels of inflammatory cytokines in the lung and serum were assessed by quantitative reverse transcription-polymerase chain reaction (qRT-PCR), Western blot and/or Enzyme-linked immunosorbent assay (ELISA).Results: SM was recognized as an active ingredient of SBPD and stably bound to Akt1. SM improved lung function and histological abnormalities, concomitant with suppressed PI3K/Akt signaling, downregulated lung and serum Interleukin 6 (IL-6) and tumor necrosis factor-α (TNF-α) levels and serum transforming growth factor-β (TGF-β) levels and upregulated lung and serum Interleukin 10 (IL-10) levels in AECOPD rats. In AECOPD rats, LY294002 restored lung function, and it also improved lung histological abnormalities and inflammation, which was found to be potentiated by SM.Conclusion: SM targets PI3K/Akt signaling to reduce lung injury and inflammation in AECOPD rats.Keywords: sangbaipi decoction, stigmasterol, acute exacerbation of chronic obstructive pulmonary disease, PI3K/Akt signaling, lung inflammation

Background and Objectives: The aging process has always been associated with a higher susceptibility to chronic inflammatory lung diseases. Several studies have demonstrated the gut microbiome's influence on the lungs through cross-talk or the gut–lungs axis maintaining nutrient-rich microenvironments. Taiwan djulis (Chenopodium formosanum Koidz.) provides antioxidant and anti-inflammatory characteristics that could modulate the gut microbiome. This could induce the gut–lung axis through microbial cross-talk, thus favoring the modulation of lung inflammation. Materials and Methods: Here, we investigate the immune mRNA expression in the spleen, fecal microbiome composition, and hyperplasia of the bronchial epithelium in aged 2-year-old BALB/c mice after 60 days of supplementation of djulis. Results: The pro-inflammatory cytokines IFN-γ, TNF-α, and IL-1β, T; cells CD4 and CD8; and TLRs TLR3, TLR4, TLR5, TLR7, TLR8, and TLR9 were reduced in their mRNA expression levels, while the anti-inflammatory cytokines IL-2, IL-4, and IL-10 were highly expressed in the C. formosanum-treated group. Interestingly, the fecal microbiome composition analysis indicated higher diversity in the C. formosanum-treated group and the presence of butyrate-producing bacteria that are beneficial in the gut microbiome. The histopathology showed reduced hyperplasia of the bronchial epithelium based on the degree of lesions. Conclusions: Our findings suggest that Taiwan djulis can modulate the gut microbiome, leading to microbial cross-talk; reducing the mRNA expression of pro-inflammatory cytokines, T cells, and TLRs; and increasing anti-inflammatory cytokines in the spleen, as cytokines migrate in the lungs, preventing lung inflammation damage in aged mice or the gut–lung axis. Thus, Taiwan djulis could be considered a beneficial dietary component for the older adult population. The major limitation includes a lack of protein validation of cytokines and TLRs and quantification of the T cell population in the spleen as a marker of the gut–lung axis. [ABSTRACT FROM AUTHOR]

Exposure to storage mite (SM) and house dust mite (HDM) allergens is a risk factor for sensitization and asthma development; however, the related immune responses and their pathology have not been fully investigated. The HDMs Dermatophagoides farinae and Dermatophagoides pteronyssinus and SM Tyrophagus putrescentiae are potent allergens that induce asthma. Most SM-related studies have focused on the allergic reactions of individuals by measuring their immunoglobulin (Ig)E expression. Considering the limited research on this topic, the present study aims to investigate the differences in the immune responses induced by HDMs and SMs and histologically analyze lung tissues in a mouse asthma model to understand the differential effects of HDM and SM. The results revealed that all mite species induced airway inflammation. Mice challenged with T. putrescentiae had the highest airway resistance and total cell, eosinophil, and neutrophil counts in the bronchoalveolar lavage fluid (BALF). The SM-sensitized groups showed more severe lesions and mucus hypersecretions than the HDM-sensitized groups. Although the degree of HDM and SM exposure was the same, the damage to the respiratory lung tissue was more severe in SM-exposed mice, which resulted in excessive mucin secretion and increased fibrosis. Furthermore, these findings suggest that SM sensitization induces a more significant hypersensitivity response in mucosal immunity than HDM sensitization in asthma models. [ABSTRACT FROM AUTHOR]

Introduction: Exposure to environmental pollutants such as diesel exhaust particles (DEP) increases the risk of respiratory disease exacerbation. However, the possible effects of these particles on the general population remain poorly understood. The present study aimed to assess the immunomodulatory and inflammatory effects of the inhalation of DEP in a model of healthy mice undergoing short-, mid- and long-term exposure. Materials and Methods: BALB/c ByJ mice were randomly divided into five experimental groups. The control group received three intranasal instillations of saline over 8 days while the other four groups received intranasal instillations of 150 µg of DEP 3 days per week for 8, 17, 26, and 53 days. Lung function assessment and flow cytometry were performed. Results: In lung tissue, intranasal exposure to DEP decreased total monocytes (p < 0.015 in all groups). At 26 days, a reduction in inflammatory monocytes and an increase in resident monocytes were observed, p = 0.001 and 0.0001, respectively. Eosinophils and neutrophils decreased at 26 days (p = 0.017 and p = 0.041, respectively). The intranasal challenges of DEP increased the total population of dendritic cells (DC) at 26 and 53 days (p = 0.017 and p = 0.022, respectively) and decreased the total and alveolar populations of macrophages (p < 0.003 for all groups compared to control), while interstitial macrophage populations increased over the time period (p = 0.0001 for all groups compared to control). Conclusions: Continuous DEP exposure triggers immune mechanisms that predispose healthy individuals to a pro-inflammatory and hyper-reactive microenvironment. This mouse model provides evidence of the capacity of DEP to increase DC, interstitial macrophages, and resident monocytes. [ABSTRACT FROM AUTHOR]

Titanium dioxide nanoparticles (TiO2NPs) are used in products that are applied to the human body, such as cosmetics and food, but their biocompatibility remains controversial. Pycnogenol (PYC), a natural extract of pine bark, exerts anti-inflammatory and antioxidant effects. In this study, we investigated whether PYC effectively alleviates pulmonary toxicity induced by airway exposure to TiO2NPs, and the beneficial effects of PYC were explained through the analysis of changes to the mechanism of cytotoxicity. TiO2NPs induced pulmonary inflammation and mucus production, increased the levels of malondialdehyde, and upregulated thioredoxin-interacting protein (TXNIP) and cleaved-caspase 3 (Cas3) in the lungs of mice. However, PYC treatment reduced the levels of all toxicity markers of TiO2NPs and restored glutathione levels. These antioxidant and anti-inflammatory effects of PYC were also demonstrated in TiO2NP-exposed human airway epithelial cells by increasing the mRNA levels of antioxidant enzymes and decreasing the expression of TXNIP, cleaved-Cas3, and inflammatory mediators. Taken together, our results showed that PYC attenuated TiO2NP-induced lung injury via TXNIP downregulation. Therefore, our results suggest the potential of PYC as an effective anti-inflammatory and antioxidant agent against TiO2NP-induced pulmonary toxicity. [ABSTRACT FROM AUTHOR]

Type I hypersensitivity reactions can result in pulmonary inflammation via increasing the bronchospasm and mucous secretions in the airways of lungs; however, the participation of neutrophils in pulmonary inflammation mediated by type I hypersensitivity reactions are incompletely understood. The present study thus aimed to examine the association between neutrophil recruitment and lung inflammation in patients with type I hypersensitivity reactions. For this purpose, blood samples, that were obtained from 128 individuals with type I hypersensitivity reactions and 40 individuals who served as the controls, were analyzed to measure the levels of immunoglobulin E (IgE), basophils, neutrophils, platelet distribution width (PDW) and red blood cell distribution width (RDW). Moreover, sputum neutrophils were also measured in both the patients and the controls. In addition, consolidation areas were identified by specialist radiologist staff. The results revealed a significant increase in the levels of IgE and basophils corresponding to 91 and 79%, respectively, in patients with type I hypersensitivity reactions. The present study also observed a marked increase in the number of neutrophils in the blood and sputum of patients. Moreover, the results revealed that the levels of PDW and RDW were significantly increased in the patients. In addition, a marked association (y=1.3061x+0.3546) (R²=0.7067) between the infiltrated neutrophils and the consolidation area in the lungs. On the whole, the present study demonstrates a notable association between neutrophil recruitment and lung inflammation in patients with type 1 hypersensitivity reactions; thus, neutrophils may prove useful as a therapeutic target for protection against pulmonary inflammation. Moreover, the presence of neutrophils in sputum may also be used as a biomarker of pulmonary inflammation mediated by type I hypersensitivity reactions. [ABSTRACT FROM AUTHOR]