Pathological Changes Of Lung Tissue Research Articles

Effects of liver X receptor in O3-induced airway inflammation and remodeling in mice.

The current clinical treatment of chronic obstructive pulmonary disease (COPD) mainly uses drugs to improve symptoms, but these drugs cannot reverse the progression of the disease and the pathological changes in lung tissue. This study aimed to investigate the effects and mechanisms of Liver X receptors (LXRs) in ozone (O3)-induced airway inflammation and remodeling in mice. Wild mice and LXR deficient mice were exposed to O3 twice a week for 6 weeks. Some wild mice were intraperitoneally injected with T0901317 (a LXR agonist) before O3 exposure. Wild mice were exposed to ambient air and intraperitoneally injected with normal saline (NS) as control group. The lung tissues and bronchoalveolar lavage fluid (BALF) were collected to evaluate airway inflammation, airway remodeling and lipid disorder. After O3 exposure, LXR deficient mice showed severe airway inflammation and airway remodeling compared with the wild mice. There were a lot of foamy macrophages appeared in BALF of LXR deficient mice. The inflammatory proteins such as myeloid differentiation primary response protein 88 (MyD88) and interleukin-1 receptor-associated kinase (IRAK) in the lung tissues of LXR deficient mice were significantly increased compared with the wild mice. In wild mice exposed to O3, T0901317 treatment can alleviate airway inflammation, airway remodeling and foamy macrophages in BALF. And MyD88 and IRAK expression in lung tissue were also attenuated by T0901317 treatment. LXRs play protective roles in O3-induced lipid accumulation, airway inflammation and airway remodeling.

Human umbilical cord mesenchymal stem cells-derived exosomes attenuate burn-induced acute lung injury via inhibiting ferroptosis

Our previous study has shown that exosomes derived from human umbilical cord mesenchymal stem cells (hUCMSCs-exo) alleviated burn-induced acute lung injury (ALI). In this study, we explored a novel mechanism by which hUCMSCs-exo contributed to the inhibition of burn-induced ALI. The ALI rat model with severe burn was established for the in vivo experiments, and rats PMVECs were stimulated with the serum from burn-induced ALI rats for the in vitro experiments. The pathological changes of lung tissues were evaluated by HE staining; the cell viability was measured using CCK-8; the iron level and Fe2+ concentration were assessed using Iron Assay Kit and Fe2+ fluorescence detection probe; the mRNA expression of SLC7A11 and GPX4 were measured by qRT-PCR; the protein levels of SLC7A11, GPX4, Nrf2 and HO-1 were detected by western blot. Both the in vivo and in vitro experiments revealed that ferroptosis was significantly induced in burn-induced ALI, which as verified by increased iron level and Fe2+ concentration, and decreased SLC7A11 and GPX4 mRNA and protein levels. Furthermore, both hUCMSCs-exo and Fer-1 (the inhibitor of ferroptosis) alleviated lung inflammation and up-regulated protein levels of Nrf2 and HO-1 in the lung tissues of burn-induced ALI rats. These results suggested that hUCMSCs-exo exhibited a protective role against burn-induced ALI by inhibiting ferroptosis, partly owing to the activation of Nrf2/HO-1 pathway, thus providing a novel therapeutic strategy for burn-induced ALI.

Hua-Shi-Bai-Du decoction inactivates NLRP3 inflammasome through inhibiting PDE4B in macrophages and ameliorates mouse acute lung injury

BackgroundHua-Shi-Bai-Du decoction (HSBD) exerts significant effects on the prevention and treatment of COVID-19 in China. The activation of the NLRP3 inflammasome of macrophages plays a vital role in COVID-19 pathology. However, no previous studies have focused on this pathological process to explore the effect of HSBD. PurposeOur aim is to uncover the effect of HSBD on NLRP3 inflammasome activation and the underlying mechanisms. MethodsThe NLRP3-activated J774A.1 cells primed by LPS and activated by nigericin/ATP/MSU were used to evaluate NLRP3 activation in vitro. ASC oligomerization and speck formation were assessed by western blot and immunofluorescence imaging. Intracellular K+ levels were determined by the colorimetric assay. Mitochondrial ROS (mtROS) level was detected by the flow cytometry and the fluorescence spectrophotometry. The intracellular cAMP level was determined by chemiluminescence method and ELISA, while phosphodiesterase (PDE) activity was measured using the fluorescent substrate MANT-cAMP. siRNA was applied to knockdown PDE4B. Two in vivo mouse models, MSU-induced peritonitis and LPS-induced acute lung injury (ALI), were used to evaluate the effects of HSBD on IL-1β and other inflammatory cytokines. Pathological changes in lung tissue were observed by histopathological examination. ResultsHSBD not only decreased supernatant IL-1β, caspase-1 p20, and cleaved gasdermin D (GSDMD) in NLRP3-activated J774A.1 cells, but also reduced IL-1β in the peritoneal lavage fluid of mice with MSU-induced peritonitis, demonstrating the suppressive effect on NLRP3 inflammasome activation. The mechanism study showed that HSBD blocked ASC oligomerization and speck formation without affecting K+ efflux or mtROS production. Furthermore, it prevented the decrease of intracellular cAMP by inhibiting PDE4B activity. And in the PDE4B-deficient cells, its suppressive effect on IL-1β release was abolished. In LPS-induced ALI mice, oral administration of HSBD decreased several proinflammatory cytokines (IL-1β, IL-6, TNF-α, and CXCL-1) and attenuated the pathological damage to the lung. ConclusionHSBD suppresses the activation of NLRP3 inflammasome by inhibiting PDE4B activity to counteract the decrease of intracellular cAMP, thereby blocking ASC oligomerization in macrophages. Our findings may provide new insight into the clinical effets of HSBD for the treatment of COVID-19.

Dachengqi decoction dispensing granule ameliorates LPS-induced acute lung injury by inhibiting PANoptosis in vivo and in vitro

Ethnopharmacological relevanceAcute lung injury (ALI) is a serious health-threatening syndrome of intense inflammatory response in the lungs, with progression leading to acute respiratory distress syndrome (ARDS). Dachengqi decoction dispensing granule (DDG) has a pulmonary protective role, but its potential modulatory mechanism to alleviate ALI needs further excavation. Aim of the studyThis study aims to investigate the effect and potential mechanism of DDG on lipopolysaccharide (LPS)-induced ALI models in vivo and in vitro. Materials and methodsLPS-treated Balb/c mice and BEAS-2B cells were used to construct in vivo and in vitro ALI models, respectively. Hematoxylin-eosin (HE), Wet weight/Dry weight (W/D) calculation of lung tissue, and total protein and Lactic dehydrogenase (LDH) assays in BALF were performed to assess the extent of lung tissue injury and pulmonary edema. Enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of tumor necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β), and interleukin-18 (IL-18) in BALF, serum, and cell supernatant. The qRT-PCR was used to detect inflammatory factors, Z-DNA binding protein 1 (ZBP1), and receptor-interacting protein kinase 1 (RIPK1) expression in lung tissues and BEAS-2B cells. Double immunofluorescence staining and co-immunoprecipitation were used to detect the relative expression and co-localization of ZBP1 and RIPK1. The effects of LPS and DDG on BEAS-2B cell activity were detected by Cell Counting Kit-8 (CCK-8). Western blot (WB) was performed to analyze the expression of PANoptosis-related proteins in lung tissues and BEAS-2B cells. ResultsIn vivo, DDG pretreatment could dose-dependently improve the pathological changes of lung tissue in ALI mice, and reduce the W/D ratio of lung, total protein concentration, and LDH content in BALF. In vitro, DDG reversed the inhibitory effect of LPS on BEAS-2B cell viability. Meanwhile, DDG significantly reduced the levels of inflammatory factors in vitro and in vivo. In addition, DDG could inhibit the expression levels of PANoptosis-related proteins, especially the upstream key regulatory molecules ZBP1 and RIPK1. ConclusionDDG could inhibit excessive inflammation and PANoptosis to alleviate LPS-induced ALI, thus possessing good anti-inflammatory and lung-protective effects. This study establishes a theoretical basis for the further development of DDG and provides a new prospect for ALI treatment by targeting PANoptosis.

Effect of macrophage-to-myofibroblast transition on silicosis.

The aim was to explore the effect of macrophage polarization and macrophage-to-myofibroblast transition (MMT) in silicosis. Male Wistar rats were divided into a control group and a silicosis group developed using a HOPE MED 8050 dynamic automatic dusting system. Murine macrophage MH-S cells were randomly divided into a control group and an SiO2 group. The pathological changes in lung tissue were observed using hematoxylin and eosin (HE) and Van Gieson (VG) staining. The distribution and location of macrophage marker (F4/80), M1 macrophage marker (iNOS), M2 macrophage marker (CD206), and myofibroblast marker (α-smooth muscle actin [α-SMA]) were detected using immunohistochemical and immunofluorescent staining. The expression changes in iNOS, Arg, α-SMA, vimentin, and type I collagen (Col I) were measured using Western blot. The results of HE and VG staining showed obvious silicon nodule formation and the distribution of thick collagen fibers in the lung tissue of the silicosis group. Macrophage marker F4/80 increased gradually from 8 to 32 weeks after exposure to silica. Immunohistochemical and immunofluorescent staining results revealed that there were more iNOS-positive cells and some CD206-positive cells in the lung tissue of the silicosis group at 8 weeks. More CD206-positive cells were found in the silicon nodules of the lung tissues in the silicosis group at 32 weeks. Western blot analysis showed that the expressions of Inducible nitric oxide synthase and Arg protein in the lung tissues of the silicosis group were upregulated compared with those of the control group. The results of immunofluorescence staining showed the co-expression of F4/80, α-SMA, and Col I, and CD206 and α-SMA were co-expressed in the lung tissue of the silicosis group. The extracted rat alveolar lavage fluid revealed F4/80+α-SMA+, CD206+α-SMA+, and F4/80+α-SMA+Col I+ cells using immunofluorescence staining. Similar results were also found in MH-S cells induced by SiO2. The development of silicosis is accompanied by macrophage polarization and MMT.

Effect of Peitu Yifei Granules on autophagy mechanism in rats with idiopathic pulmonary fibrosis based on PI3K/Akt/mTOR signaling pathway

To investigate the mechanism by which Peitu Yifei Granules inhibit idiopathic pulmonary fibrosis(IPF) in rats, fifty specific-pathogen-free(SPF) grade male Wistar rats were randomly divided into blank group and modeling group. IPF was induced in the modeling group rats by tracheal infusion of 5 mg·kg~(-1) bleomycin(BLM) and then randomly divided into model group, pirfenidone group, and high-dose, medium-dose, and low-dose groups treated with Peitu Yifei Granules. After 24 hours of modeling, the treatment groups received intragastric administration of either Peitu Yifei Granules or pirfenidone as a positive control drug; meanwhile, the model group received an equal volume of normal saline. After 21 days of treatment administration, lung tissue samples were collected for analysis. Pathological changes in lung tissues were assessed using hematoxylin-eosin(HE) staining and Masson's trichrome staining. The expression levels of protein kinase B(Akt), mammalian target of rapamycin(mTOR), their phosphorylated forms, and sequestosome 1(p62) were determined through Western blot(WB). Fluorescent quantitative real-time polymerase chain reaction(RT-qPCR) was used to measure messenger ribonucleic acid(mRNA) expression levels of Beclin-1, microtubule-associated proteins 1A/1B light chain 3B(LC3B), and p62. Immunohistochemistry was performed to assess protein expression levels of Beclin-1 and LC3B in lung tissue samples. RESULTS:: demonstrated that lung tissue structure appeared normal without significant collagen deposition in the blank group rats. In contrast, rats from the model group exhibited thickened alveolar septa along with evident inflammatory changes and collagen deposition. Compared to the model group rats, those treated with Peitu Yifei Granules or pirfenidone showed significantly improved lung tissue structure with reduced inflammation and collagen deposition observed histologically. Furthermore, compared with those of the blank group, the expressions of p62 and its mRNA, p-Akt and p-mTOR protein in lung tissues of the model group were significantly increased, while Beclin-1, LC3B and their mRNA levels were significantly decreased. Compared with those of the model group, the expressions of p62 and its mRNA, p-Akt and p-mTOR in lung tissues of the pirfenidone group and Peitu Yifei Granules high-dose and medium-dose groups were significantly decreased, while Beclin-1, LC3B and their mRNA expressions were significantly increased. The above results indicate that Peitu Yifei Granules can improve autophagy levels in lung tissues by inhibiting the phosphoinositide 3-kinase(PI3K)/Akt/mTOR signaling pathway and delay the development of IPF disease.

Anthrahydroquinone‑2,6‑disulfonate attenuates PQ‑induced acute lung injury through decreasing pulmonary microvascular permeability via inhibition of the PI3K/AKT/eNOS pathway.

In paraquat (PQ)‑induced acute lung injury (ALI)/ acute respiratory distress syndrome, PQ disrupts endothelial cell function and vascular integrity, which leads to increased pulmonary leakage. Anthrahydroquinone‑2,6‑disulfonate (AH2QDS) is a reducing agent that attenuates the extent of renal injury and improves survival in PQ‑intoxicated Sprague‑Dawley (SD) rats. The present study aimed to explore the beneficial role of AH2QDS in PQ‑induced ALI and its related mechanisms. A PQ‑intoxicated ALI model was established using PQ gavage in SD rats. Human pulmonary microvascular endothelial cells (HPMECs) were challenged with PQ. Superoxide dismutase, malondialdehyde, reactive oxygen species and nitric oxide (NO) fluorescence were examined to detect the level of oxidative stress in HPMECs. The levels of TNF‑α, IL‑1β and IL‑6 were assessed using an ELISA. Transwell and Cell Counting Kit‑8 assays were performed to detect the migration and proliferation of the cells. The pathological changes in lung tissues and blood vessels were examined by haematoxylin and eosin staining. Evans blue staining was used to detect pulmonary microvascular permeability. Western blotting was performed to detect target protein levels. Immunofluorescence and immunohistochemical staining were used to detect the expression levels of target proteins in HPMECs and lung tissues. AH2QDS inhibited inflammatory responses in lung tissues and HPMECs, and promoted the proliferation and migration of HPMECs. In addition, AH2QDS reduced pulmonary microvascular permeability by upregulating the levels of vascular endothelial‑cadherin, zonula occludens‑1 and CD31, thereby attenuating pathological changes in the lungs in rats. Finally, these effects may be related to the suppression of the phosphatidylinositol‑3‑kinase (PI3K)/protein kinase B (AKT)/endothelial‑type NO synthase (eNOS) signalling pathway in endothelial cells. In conclusion, AH2QDS ameliorated PQ‑induced ALI by improving alveolar endothelial barrier disruption via modulation of the PI3K/AKT/eNOS signalling pathway, which may be an effective candidate for the treatment of PQ‑induced ALI.

Establishment of a Mouse Model of Mycoplasma pneumoniae-Induced Plastic Bronchitis.

Plastic bronchitis (PB) constitutes a life-threatening pulmonary disorder, predominantly attributed to Mycoplasma pneumoniae (MP) infection. The pathogenic mechanisms involved remain largely unexplored, leading to the absence of reliable approaches for early diagnosis and clear treatment. Thus, the present investigation aimed to develop an MP-induced mouse model of PB, thereby enhancing our understanding of this complex condition. In the first stage, healthy BALB/c mice were utilized to investigate the optimal methods for establishing PB. This involved the application of nebulization (15-20 min) and intratracheal administration (6-50 μL) with 2-chloroethyl ethyl sulfide (CEES) concentrations ranging from 4.5% to 7.5%. Subsequently, the MP model was induced by administering an MP solution (2 mL/kg/day, 108 CFU/50 μL) via the intranasal route for a duration of five consecutive days. Ultimately, suitable techniques were employed to induce plastic bronchitis in the MP model. Pathological changes in lung tissue were analyzed, and immunohistochemistry was employed to ascertain the expression levels of vascular endothelial growth factor receptor 3 (VEGFR-3) and the PI3K/AKT/mTOR signaling pathway. The administration of 4.5% CEES via a 6 µL trachea was the optimal approach to establishing a PB model. This method primarily induced neutrophilic inflammation and fibrinous exudate. The MP-infected group manifested symptoms indicative of respiratory infection, including erect hair, oral and nasal secretions, and a decrease in body weight. Furthermore, the pathological score of the MP+CEES group surpassed that of the groups treated with MP or CEES independently. Notably, the MP+CEES group demonstrated significant activation of the VEGFR-3 and PI3K/AKT/mTOR signaling pathways, implying a substantial involvement of lymphatic vessel impairment in this pathology. This study successfully established a mouse model of PB induced by MP using a two-step method. Lymphatic vessel impairment is a pivotal element in the pathogenetic mechanisms underlying this disease entity. This accomplishment will aid in further research into treatment methods for patients with PB caused by MP.

Exploration of Antimicrobial Peptides in the Treatment of Gentamicin-Resistant Klebsiella pneumoniae Infection.

The emergence of multidrug-resistant Klebsiella pneumoniae (K. pneumoniae) and the decline of effective antibiotics lead to the urgent need for new antibacterial agents. The aim of this study is to investigate the therapeutic effect of antimicrobial peptides against gentamicin-resistant (RT) K. pneumoniae and to screen effective antimicrobial peptides. In this study, the RT strains were induced by gradient gentamicin, and the RT strains were selected by detecting the expression levels of efflux pump genes, porin genes, and biofilm formation genes of the strains combined with their effects on the cells. Then the effects of four antimicrobial peptides on the efflux pump activity, biofilm formation level and cell condition after infection were detected to explore the effects of antimicrobial peptides on RT strains. Finally, the RT strain was used to induce a mouse model of pneumonia, and the four antimicrobial peptides were used to treat pneumonia mice for in vivo experiments. The pathological changes in lung tissues in each group were detected to explore the antimicrobial peptide with the most significant effect on the RT strain in vivo. The results showed that the minimal inhibitory concentrations of the RT strains (strain C and strain I) were significantly higher than those of the wild-type strain, and the expression of efflux pump, porin and biofilm formation genes was significantly increased. The antimicrobial peptides could effectively inhibit the biofilm formation and efflux pump protein function of the RT strains. In addition, the antimicrobial peptides showed promising antibacterial effects both in vitro and in vivo. Our study provided a theoretical basis for the treatment of gentamicin resistant K. pneumoniae infection with antimicrobial peptides, and found that KLA was significantly superior to LL37, Magainin I, KLA and Dermaseptin (10 μg/mL in cells, 50 μg in mice).

Dynamic changes in autophagy activity in different degrees of pulmonary fibrosis in mice.

The aim of this study is to observe the changes in autophagy activities in lung tissues of mice with different degrees of pulmonary fibrosis (PF), and explore the association between PF and autophagy activity. The PF model was established by bleomycin (BLM, 25 and 35 mg/kg) atomization inhalation in C57BL/6 mice, samples were collected on the 7, 14, and 28 days after BLM administration. Hematoxylin-eosin staining was used to observe the pathological changes in lung tissues. Masson staining was utilized to assess areas of blue collagen fiber deposition in lung tissues. Quantitative real time polymerase chain reaction was used to detect the mRNA expressions of autophagy-related genes, including Atg5, Atg7, and Atg10 in lung tissues. Western blot was used to detect the protein expressions of autophagy-related genes, including p62 and LC3II/LC3I in lung tissues. Compared with control group, BLM dose-dependently decreased PaO2, mRNA expressions of Atg5, Atg7, Atg10, and LC3II/LC3I, while increased lung wet weight, lung coefficient, PF score, the blue area of collagen fibers, and p62 protein on the 7th, 14th, and 28th days. In conclusion, the more severe the PF induced by BLM, the lower the autophagy activity.

MiRNA-206-3p alleviates LPS-induced acute lung injury via inhibiting inflammation and pyroptosis through modulating TLR4/NF-κB/NLRP3 pathway

Acute lung injury (ALI) is life-threatening. MicroRNAs (miRNAs) are often abnormally expressed in inflammatory diseases and are closely associated with ALI. This study investigates whether miRNA-206-3p attenuates pyroptosis in ALI and elucidates the underlying molecular mechanisms. ALI mouse and cell models were established through lipopolysaccharide (LPS) treatment for 24 h. Subsequently, the models were evaluated based on ultrasonography, the lung tissue wet/dry (W/D) ratio, pathological section assessment, electron microscopy, and western blotting. Pyroptosis in RAW264.7 cells was then assessed via electron microscopy, immunofluorescence, and western blotting. Additionally, the regulatory relationship between miRNA-206-3p and the Toll-like receptor (TLR)4/nuclear factor (NF)-κB/Nod-like receptor protein-3 (NLRP3) pathway was verified. Finally, luciferase reporter gene and RNA pull-down assays were used to verify the targeting relationship between miRNA-206-3p and TLR4. miRNA206-3p levels are significantly decreased in the LPS-induced ALI model. Overexpression of miRNA-206-3p improves ALI, manifested as improved lung ultrasound, improved pathological changes of lung tissue, reduced W/D ratio of lung tissue, release of inflammatory factors in lung tissue, and reduced pyroptosis. Furthermore, overexpression of miRNA-206-3p contributed to reversing the ALI-promoting effect of LPS by hindering TLR4, myeloid differentiation primary response 88 (MyD88), NF-κB, and NLRP3 expression. In fact, miRNA-206-3p binds directly to TLR4. In conclusion, miRNA-206-3p alleviates LPS-induced ALI by inhibiting inflammation and pyroptosis via TLR4/NF-κB/NLRP3 pathway modulation.

DYNAMIC CHANGES IN HISTOLOGICAL AND MORPHOMETRIC INDICATORS OF THE LUNGS IN SEXUALLY IMMATURE RATS DURING SIMULATION OF PARTIAL TRACHEAL STENOSIS

Introduction. The morphological features of the respiratory system in laryngomalacia remain insufficiently understood, particularly regarding structural, cytological, and functional alterations. The aim of this study is to investigate the morphological characteristics of the respiratory compartment in the lungs of sexually immature rats, conduct a morphometric assessment of lung tissue density, analyze the dynamics of erythrocyte mass and collagen accumulation, and identify correlations between these parameters. Materials and Methods: The study involved sexually immature male Wistar rats aged 25-28 days and weighing 40-55 g. Partial tracheal stenosis was induced in experimental animals using a developed method, restricting the tracheal lumen by 20-25%. The stenosis was maintained for 7 and 21 days in different groups. In one group, tracheal stenosis was relieved after 7 days by removing the compressive ligature. Histological, histochemical, and morphometric methods were employed to study changes in lung tissue. Results. Pathological changes in lung tissue during hypoxia were characterized by an increase in the number of different types of cells and erythrocyte mass, especially on the 21st day of the experiment and the removal of ligatures from the trachea in experimental animals. Disturbances in the microcirculation of the lung acini were manifested by a sharp increase in blood filling of the microvessels and expansion of their lumen. In this case, the process of erythrocyte penetration into the lumen of the alveoli was sometimes noted. The results of histochemical detection of collagen indicate that in the lung tissue of experimental animals there is no activation of fibrogenetic processes, which would be accompanied by a simultaneous increase in the specific density of collagen. Indicators characterizing the lung tissue (number of cells, their specific density) made it possible to evaluate the corresponding correlations. At the same time, they were not associated with the level of collagen or erythrocyte density in the studied loci of the respiratory system of experimental sexually immature rats. A significant increase in the specific density of erythrocyte mass in lung tissue did not depend on the duration of the experiment. Removal of the ligature and restoration of the tracheal lumen did not significantly affect the restoration of alveolar acini and the spectrum of identified cells. In addition, an increase in the specific density of lung tissue was observed. Conclusion. The findings of this study contribute to deeper understanding of lung damage in children with laryngomalacia and associated respiratory system ventilation impairment. The observed reactive changes in lung connective tissue and collagen synthesis during hypoxia do not necessarily indicate the development of respiratory system fibrosis. However, longer exposure to hypoxic conditions may increase the risk of fibrosis in children.

High humidity and NO2 co-exposure exacerbates allergic asthma by increasing oxidative stress, inflammatory and TRP protein expressions in lung tissue

Allergic asthma is a chronic inflammatory airway disease with a high mortality rate and a rapidly increasing prevalence in recent decades that is closely linked to environmental change. Previous research found that high humidity (HH) and the traffic-related air pollutant NO2 both aggregated allergic asthma. Their combined effect and mechanisms on asthma exacerbation, however, are unknown. Our study aims to toxicologically clarify the role of HH (90%) and NO2 (5 ppm) on allergic asthma. Ninety male Balb/c mice were randomly assigned to one of six groups (n = 15 in each): saline control, ovalbumin (OVA)-sensitized, OVA + HH, OVA + NO2, OVA + HH + NO2, and OVA + HH + NO2+Capsazepine (CZP). After 38 days of treatment, the airway function, pathological changes in lung tissue, blood inflammatory cells, and oxidative stress and inflammatory biomarkers were comprehensively assessed. Co-exposure to HH and NO2 exacerbated histopathological changes and airway hyperresponsiveness, increased IgE, oxidative stress markers malonaldehyde (MDA) and allergic asthma-related inflammation markers (IL-1β, TNF-α and IL-17), and upregulated the expressions of the transient receptor potential (TRP) ion channels (TRPA1, TRPV1 and TRPV4). Our findings show that co-exposure to HH and NO2 disrupted the Th1/Th2 immune balance, promoting allergic airway inflammation and asthma susceptibility, and increasing TRPV1 expression, whereas CZP reduced TRPV1 expression and alleviated allergic asthma symptoms. Thus, therapeutic treatments that target the TRPV1 ion channel have the potential to effectively manage allergic asthma.

Scutellaria baicalensis water decoction ameliorates lower respiratory tract infection by modulating respiratory microbiota

BackgroundThe pathogenesis of lower respiratory tract infections (LRTIs) has been demonstrated to be strongly associated with dysbiosis of respiratory microbiota. Scutellaria baicalensis, a traditional Chinese medicine, is widely used to treat respiratory infections. However, whether the therapeutic effect of S. baicalensis on LRTIs depends upon respiratory microbiota regulation is largely unclear. PurposeTo investigate the potential effect and mechanism of S. baicalensis on the respiratory microbiota of LRTI mice. MethodsA mouse model of LRTI was established using Klebsiella pneumoniae or Streptococcus pneumoniae. Antibiotic treatment was administered, and transplantation of respiratory microbiota was performed to deplete the respiratory microbiota of mice and recover the destroyed microbial community, respectively. High-performance liquid chromatography (HPLC) was used to determine and quantify the chemical components of S. baicalensis water decoction (SBWD). Pathological changes in lung tissues and the expressions of serum inflammatory cytokines, including interleukin-17A (IL-17A), granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α), were determined by hematoxylin and eosin (H&E) staining and enzyme-linked immunosorbent assay (ELISA), respectively. Quantitative real-time PCR (qRT-PCR) analysis was performed to detect the mRNA expression of GM-CSF. Metagenomic sequencing was performed to evaluate the effect of SBWD on the composition and function of the respiratory microbiota in LRTI mice. ResultsSeven main components, including scutellarin, baicalin, oroxylin A-7-O-β-d-glucuronide, wogonoside, baicalein, wogonin, and oroxylin A, were identified and their levels in SBWD were quantified. SBWD ameliorated pulmonary pathological injury and inflammatory responses in K. pneumoniae and S. pneumoniae-induced LRTI mice, as evidenced by the dose-dependent reductions in the levels of serum inflammatory cytokines, IL-6 and TNF-α. SBWD may exert a bidirectional regulatory effect on the host innate immune responses in LRTI mice and regulate the expressions of IL-17A and GM-CSF in a microbiota-dependent manner. K. pneumoniae infection but not S. pneumoniae infection led to dysbiosis in the respiratory microbiota, evident through disturbances in the taxonomic composition characterized by bacterial enrichment, including Proteobacteria, Enterobacteriaceae, and Klebsiella. K. pneumoniae and S. pneumoniae infection altered the bacterial functional profile of the respiratory microbiota, as indicated by increases in lipopolysaccharide biosynthesis, metabolic pathways, and carbohydrate metabolism. SBWD had a certain trend on the regulation of compositional disorders in the respiratory flora and modulated partial microbial functions embracing carbohydrate metabolism in K. pneumoniae-induced LRTI mice. ConclusionSBWD may exert an anti-infection effect on LRTI by targeting IL-17A and GM-CSF through respiratory microbiota regulation. The mechanism of S. baicalensis action on respiratory microbiota in LRTI treatment merits further investigation.

Mechanism of total glucosides of White Paeony Capsules in ameliorating acute lung injury based on NLRP3 inflammasome

This study deciphered the ameliorating effect and molecular mechanism of the total glucosides of White Paeony Capsules(TGP) in the treatment of mice model with acute lung injury(ALI) via NOD-like receptor thermal protein domain associated protein 3(NLRP3) signaling pathway of the inflammasome. The study established an inflammasome activation model of primed bone marrow-derived macrophages(BMDMs), and its molecular mechanism was investigated by Western blot(WB), immunofluorescence staining, enzyme-linked immunosorbent assay(ELISA), and flow cytometry. C57BL/6J mice were randomly divided into a blank control group, a TGP group, a model group(LPS group), LPS+low-and high-dose TGP groups, LPS+MCC950 group, and LPS+MCC950+TGP group, with eight mice per group. The ALI model was induced in mice. Finally, bronchoalveolar lavage fluid(BALF) and lung tissue were collected. Lung index and lung weight wet-to-dry ratio were determined for each group of mice. The pathological changes in lung tissue were observed through hematoxylin-eosin(HE) staining. The number of neutrophils in the BALF of each group was detected using flow cytometry. The levels of interleukin(IL)-1β, IL-6, and tumor necrosis factor(TNF)-α in the BALF were determined by ELISA. The expressions of IL-1β, IL-18, IL-6, and TNF-α in the lung tissue were determined by real-time quantitative PCR(RT-qPCR). This study demonstrated that TGP dramatically blocked the activation of the NLRP3 inflammasome by inhibiting the production of upstream mitochondrial reactive oxygen species(mtROS) and the subsequent oligomerization of apoptosis-associated specks(ASC). Additionally, in the ALI mice model, compared with the blank control group, the model group showed alveolar structure rupture, thic-kening of alveolar septa, and dramatically increased lung index, lung weight wet-to-dry ratio in lung tissue, neutrophil count, and inflammatory factor levels. Compared with the model group, the pathological morphology of lung tissue was significantly ameliorated in the TGP and MCC950 groups, and the lung index and lung weight wet-to-dry ratio were significantly reduced. Neutrophil counts were reduced, and levels of inflammatory factors were significantly downregulated. Notably, compared with the MCC950 group, there was no significant difference in effect in the MCC950+TGP group. Collectively, the study reveals that TGP may ameliorate ALI in mice by inhibiting the activation of NLRP3 inflammasome, providing a safe and effective drug candidate for the prevention or treatment of ALI/ARDS.

The Regulation of the Function of Fibroblasts in Patients with Chronic Obstructive Pulmonary Disease by Regulating Tenascin-C Protein Under Feedback Lung Training with Curcumin in Combination with Suzi Jiangqi Decoction

Chronic obstructive pulmonary disease (COPD) is characterized by reduction of elastic fibers in alveolar wall. This study explores the mechanism of curcumin combined with Suzi Jiangqi Decoction in lung fibroblasts. 50 COPD patients suspected of lung cancer were collected. Ten patients were assigned into control group, and the remaining 40 patients underwent feedback lung training and were divided into model group, curcumin group, Suzi Jiangqi decoction group, and curcumin combined with Suzi Jiangqi decoction group. 5 mL peripheral venous blood was collected and a percutaneous lung biopsy was performed to collect lung tissue and culture fibroblasts. Tenascin (TNC) level was detected by ELISA and pathological changes of lung tissue were detected by HE staining. CCK-8 assay detected cell proliferation and Transwell chamber detected cell migration. Cell apoptosis was assessed by flow cytometry and TGF-β1, MMP-9, and TNC expression were evaluated by Real Time Quantitative Polymerase Chain Reaction (RT-qPCR) and Western blot. TNC level in COPD patients decreased significantly and levels of various pulmonary function indexes showed an upward trend. The epithelial cells in lung tissue of control group were less and alveolar wall was obviously thinner. Epithelial cells gradually increased and alveolar walls gradually fused. TNC protein can improve the development of fibroblasts in COPD patients. Curcumin combined with Suzi Jiangqi Decoction inhibited TNC expression, and down-regulated TGF-β1 and MMP-9. Curcumin combined with Suzi Jiangqi decoction increased the proliferation ability and reduced apoptosis of lung fibroblasts by down-regulating the expression of Tenascin-C. This study provides a solid theoretical basis for curcumin combined with Suzi Jiangqi Decoction as a treatment for COPD.

Hydrogen therapy promotes macrophage polarization to the M2 subtype in radiation lung injury by inhibiting the NF-κB signalling pathway

BackgroundRadiotherapy has become a standard treatment for chest tumors, but a common complication of radiotherapy is radiation lung injury. Currently, there is still a lack of effective treatment for radiation lung injury. MethodsA mouse model of radioactive lung injury (RILI) was constructed and then treated with different cycles of hydrogen inhalation. Lung function tests were performed to detect changes in lung function.HE staining was used to detect pathological changes in lung tissue. Immunofluorescence staining was used to detect the polarization of macrophages in lung tissue. Immunohistochemistry was used to detect changes in cytokine expression in lung tissues. Western Blot was used to detect the expression of proteins related to the NF-κB signalling pathway. ResultsLung function test results showed that lung function decreased in the model group and improved in the treatment group.HE staining showed that inflammatory response was evident in the model group and decreased in the treatment group. Immunohistochemistry results showed that the expression of pro-inflammatory factors was significantly higher in the model group, and the expression of pro-inflammatory factors was significantly higher in the treatment group. The expression of pro-inflammatory factors in the treatment group was significantly lower than that in the model group, and the expression of anti-inflammatory factors in the treatment group was higher than that in the model group. Immunofluorescence showed that the expression of M1 subtype macrophages was up-regulated in the model group and down-regulated in the treatment group. The expression of M2 subtype macrophages was up-regulated in the treatment group relative to the model group. Western Blot showed that P–NF-κB p65/NF-κB p65 was significantly increased in the model group, and P–NF-κB p65/NF-κB p65 was decreased in the treatment group. ConclusionHydrogen therapy promotes macrophage polarization from M1 to M2 subtypes by inhibiting the NF-κB signalling pathway, thereby attenuating the inflammatory response to radiation lung injury.

TM6SF1 suppresses the progression of lung adenocarcinoma and M2 macrophage polarization by inactivating the PI3K/AKT/mtor pathway

Transmembrane 6 superfamily 1 (TM6SF1) is lowly expressed in lung adenocarcinoma (LUAD), but the function and mechanisms of TM6SF1 remain unclear. Thus, we attempt to explore the function of TM6SF1 and its underlying mechanisms in LUAD. qRT-PCR was used for detecting TM6SF1 mRNA expression. Immunohistochemistry staining was used for detecting the expression of MMP-2, TM6SF1, Ki67, MMP-9, and CD163 proteins. E-cadherin, p-PI3K, Vimentin, AKT, N-cadherin, PI3K, p-AKT, mTOR, p-mTOR, and marker proteins of M2 macrophages were evaluated using Western blot. CD206 protein expression was examined via immunofluorescence. The IL-10 concentration was measured via enzyme-linked immunosorbent assay (ELISA). Using CCK-8, colony formation and transwell assays, cell proliferation, migration, and invasion were assessed. A549 cells were injected into the mice's flank for establishing a mouse tumor model and into the tail vein for establishing the lung metastasis model. HE staining was performed to detect pathological changes in lung tissues. Decreased TM6SF1 expression was found in LUAD tissues and cells. TM6SF1 overexpression inhibited cell viability, proliferation, invasion, migration, EMT, and polarization of M2 macrophages in LUAD cells, along with tumor growth and metastasis in xenograft mice. Bioinformatics analysis demonstrated that TM6SF1 was correlated with the tumor microenvironment. TM6SF1 overexpression reduced expression levels of p-mTOR, p-PI3K, p-AKT, mTOR, and AKT. TM6SF1-caused inhibition of proliferation, migration, invasion and EMT, as M2 macrophage polarization was reversed by the PI3K activator in LUAD cells. TM6SF1 inactivated the PI3K/AKT/mTOR pathway to suppress LUAD malignancy and polarization of M2 macrophages, providing insight for developing new LUAD treatments.

Salidroside Ameliorates Lung Injury Induced by PM2.5 by Regulating SIRT1-PGC-1α in Mice

ObjectiveThis study aimed to clarify the intervention effect of salidroside (SAL) on lung injury caused by PM2.5 in mice and illuminate the function of SIRT1-PGC-1ɑ axis. MethodsSpecific pathogen-free (SPF) grade male C57BL/6 mice were randomly assigned to the following groups: control group, SAL group, PM2.5 group, SAL+PM2.5 group. On the first day, SAL was given by gavage, and on the second day, PM2.5 suspension was given by intratracheal instillation. The whole experiment consist of a total of 10 cycles, lasting 20 days. At the end of treatment, blood samples and lung tissues were collected and analyzed. Observation of pathological changes in lung tissue using inverted microscopy and transmission electron microscopy. The expression of inflammatory, antioxidants, apoptosis, and SIRT1-PGC-1ɑ proteins were detected by Western blotting. ResultsExposure to PM2.5 leads to obvious morphological and pathologica changes in the lung of mice. PM2.5 caused a decline in levels of antioxidant-related enzymes and protein expressions of HO-1, Nrf2, SOD2, SIRT1 and PGC-1ɑ, and an increase in the protein expressions of IL-6, IL-1β, Bax, caspase-9 and cleaved caspase-3. However, SAL reversed the aforementioned changes caused by PM2.5 by activating the SIRT1-PGC-1α pathway. ConclusionSAL can activate SIRT1-PGC-1ɑ to ameliorate PM2.5-induced lung injury.

Exploring the immune-inflammatory mechanism of Maxing Shigan Decoction in treating influenza virus A-induced pneumonia based on an integrated strategy of single-cell transcriptomics and systems biology.

Influenza is an acute respiratory infection caused by influenza virus. Maxing Shigan Decoction (MXSGD) is a commonly used traditional Chinese medicine prescription for the prevention and treatment of influenza. However, its mechanism remains unclear. The mice model of influenza A virus pneumonia was established by nasal inoculation. After 3days of intervention, the lung index was calculated, and the pathological changes of lung tissue were detected by HE staining. Firstly, transcriptomics technology was used to analyze the differential genes and important pathways in mouse lung tissue regulated by MXSGD. Then, real-time fluorescent quantitative PCR (RT-PCR) was used to verify the changes in mRNA expression in lung tissues. Finally, intestinal microbiome and intestinal metabolomics were performed to explore the effect of MXSGD on gut microbiota. The lung inflammatory cell infiltration in the MXSGD group was significantly reduced (p < 0.05). The results of bioinformatics analysis for transcriptomics results show that these genes are mainly involved in inflammatory factors and inflammation-related signal pathways mediated inflammation biological modules, etc. Intestinal microbiome showed that the intestinal flora Actinobacteriota level and Desulfobacterota level increased in MXSGD group, while Planctomycetota in MXSGD group decreased. Metabolites were mainly involved in primary bile acid biosynthesis, thiamine metabolism, etc. This suggests that MXSGD has a microbial-gut-lung axis regulation effect on mice with influenza A virus pneumonia. MXSGD may play an anti-inflammatory and immunoregulatory role by regulating intestinal microbiome and intestinal metabolic small molecules, and ultimately play a role in the treatment of influenza A virus pneumonia.