Methyl p‑hydroxycinnamate (MH), an esterified derivative of p‑Coumaric acid exerts anti‑inflammatory effects on lipopolysaccharide (LPS)‑stimulated RAW264.7 macrophages. Based on these effects, the present study investigated the protective role of MH in a mouse model of LPS‑induced acute respiratory distress syndrome (ARDS). The results demonstrated that administration of LPS (5 mg/kg intranasally) markedly increased the neutrophil/macrophage numbers and levels of inflammatory molecules (TNF‑α, IL‑6, IL‑1β and reactive oxygen species) in the bronchoalveolar lavage fluid (BALF) of mice. On histological examination, the presence of inflammatory cells was observed in the lungs of mice administered LPS. LPS also notably upregulated the secretion of monocyte chemoattractant protein‑1 and protein content in BALF as well as expression of inducible nitric oxide synthase in the lungs of mice; it also caused activation of p38 mitogen‑activated protein kinase (MAPK) and NF‑κB signaling. However, MH treatment significantly suppressed LPS‑induced upregulation of inflammatory cell recruitment, inflammatory molecule levels and p38MAPK/NF‑κB activation, and also led to upregulation of heme oxygenase‑1 (HO‑1) expression in the lungs of mice. In addition, the ability of MH to induce HO‑1 expression was confirmed in RAW264.7 macrophages. Taken together, the findings of the present study indicated that MH may exert protective effects against airway inflammation in ARDS mice by inhibiting inflammatory cell recruitment and the production of inflammatory molecules.

The aim of the present study was to explore the roles of OX40/OX40 ligand (OX40L) signaling and OX40+ T cells in ovalbumin (OVA)‑induced mouse asthma model. Asthma was induced by OVA exposure and subsequent co‑treatment with OX40L protein, neutralizing anti‑OX40L blocking antibody, OX40+ T cells or PBS. The protein expression levels of interleukin (IL)‑4, IL‑6, IL‑13, IL‑17, tumor necrosis factor (TNF)‑α and interferon (IFN)‑γ in bronchoalveolar lavage fluid (BALF) were examined using murine cytokine‑specific ELISA. Eosinophil accumulation as well as proliferation and apoptosis of T cells in BALF were detected by Cell Counting kit‑8 and flow cytometric assays. Expression of the apoptosis‑related protein cleaved caspase‑3 was examined in OX40+ T cells using western blot assay. Flow cytometric analysis revealed that OVA‑treated mice that were co‑treated with OX40L or OX40+ T cells exhibited higher eosinophil infiltration compared with control mice treated only with OVA, whereas neutralizing anti‑OX40L blocking antibody inhibited eosinophil infiltration. ELISA assays demonstrated that the expression of IL‑4, IL‑6, IL‑13, IL‑17, TNF‑α and IFN‑γ in BALF in OX40L‑treated and OX40+ T cell‑treated mice was increased compared with expression levels in control mice. Treatment with OX40L protein effectively reduced apoptosis of T cells and the expression of cleaved caspase‑3 in T cells. OX40L‑treated and OX40+ T cell‑treated mice exhibited increased asthma through OX40/OX40L signaling, which probably promoted inflammatory factor expression, eosinophil infiltration and T cell proliferation.

JNK serves critical roles in numerous types of inflammation‑ and oxidative stress‑induced disease, including acute lung injury (ALI). JNK‑IN‑8 is the first irreversible JNK inhibitor that has been described. However, whether JNK‑IN‑8 can prevent lipopolysaccharide (LPS)‑induced ALI by inhibiting JNK activation and its downstream signaling is poorly understood. The objective of the present study was to investigate the specific therapeutic effects of JNK‑IN‑8 on LPS‑induced ALI and the molecular mechanisms involved. JNK‑IN‑8 attenuated myeloperoxidase activity, malondialdehyde and superoxide dismutase content and the lung wet/dry ratio, and improved the survival rate following lethal injection of LPS. Additionally, JNK‑IN‑8 decreased bronchoalveolar lavage fluid protein levels, lactate dehydrogenase activity, neutrophil infiltration and the number of macrophages (as demonstrated by flow cytometry), as well as the production of TNF‑α, IL‑6 and IL‑1β (as evaluated via ELISA). In addition, reverse transcription‑quantitative PCR and ELISA showed that JNK‑IN‑8 attenuated LPS‑induced inflammatory cytokine production and oxidative stress in primary murine peritoneal macrophages and RAW264.7 cells in vitro. Furthermore, the present study demonstrated that the JNK/NF‑κB signaling pathway was involved in the therapeutic effect of JNK‑IN‑8 against LPS‑induced injury both in vivo and in vitro. In conclusion, these findings indicated that JNK‑IN‑8 had a therapeutic effect on LPS‑induced ALI in mice. The mechanism may be associated with inhibition of the JNK/NF‑κB signaling pathway. JNK‑IN‑8 may be a potential therapeutic agent for the treatment of ALI.

Dihydromyricetin (DHM) is a plant flavonoid and is the primary active ingredient isolated from the medicinal herb, Ampelopsis grossedentata. DHM has been shown to possess various pharmacological activities, including anti‑inflammatory effects. However, the possible role of DHM in asthma treatment remains to be elucidated. The present study aimed to investigate its anti‑inflammatory properties in mice with symptoms of allergic asthma. The C57BL/6 mice were sensitized and challenged with ovalbumin (OVA) to induce asthma. DHM or phosphate‑buffered saline treatment was administered 1 h prior to the OVA challenge. The levels of interleukin (IL)‑4, IL‑5 and IL‑13 in the bronchoalveolar lavage (BAL) fluid were measured by enzyme‑linked immunosorbent assay (ELISA), and OVA‑specific serum IgE and IgG1 levels were also determined by ELISA. Histopathological staining was performed to evaluate the infiltration of inflammatory cells into the BAL fluid, lung tissues and goblet cell hyperplasia. DHM treatment significantly reduced the total number of inflammatory cells, including eosinophils, neutrophils, lymphocytes and macrophages, in the BAL fluid. DHM also reduced the levels of IL‑4, IL‑5 and IL‑13 in the BAL fluid, and reduced the secretion of OVA‑specific IgE and IgG1 in the serum. The histological staining demonstrated that DHM treatment effectively suppressed the OVA‑induced inflammatory cells in the lung tissues and in the mucus hypersecreted by goblet cells in the airway. These results showed that DHM had a potent anti‑inflammatory effect in an OVA‑induced mouse model of asthma, offering potential as an anti‑inflammatory agent for the treatment of asthma.

P2X4 receptor (P2X4R) is the most widely expressed subtype of the P2XRs in the purinergic receptor family. Adenosine triphosphate (ATP), a ligand for this receptor, has been implicated in the pathogenesis of asthma. ATP‑P2X4R signaling is involved in pulmonary vascular remodeling, and in the proliferation and differentiation of airway and alveolar epithelial cell lines. However, the role of P2X4R in asthma remains to be elucidated. This aim of the present study was to investigate the effects of P2X4R in a murine experimental asthma model. The asthmatic model was established by the inhalation of ovalbumin (OVA) in BALB/c mice. The mice were treated with P2X4R‑specific agonists and antagonists to investigate the role of this receptor in vivo. Pathological changes in the bronchi and lung tissues were examined using hematoxylin and eosin staining, Masson's trichrome staining and Alcian blue staining. The inflammatory cells in the bronchoalveolar lavage fluid were counted, and the expression levels of P2X4R, α‑smooth muscle actin (α‑SMA) and proliferating cell nuclear antigen (PCNA) were detected using western blotting. In the OVA‑challenged mice, inflammation, infiltration, collagen deposition, mucus production, and the expression levels of P2X4R and PCNA were all increased; however, the expression of α‑SMA was decreased, compared with the mice in the control group. Whereas treatment with the P2X4R agonist, ATP, enhanced the allergic reaction, treatment with the P2X4R antagonist, 5‑BDBD, attenuated the allergic reaction. The results suggested that ATP‑P2X4R signaling may not only contribute to airway inflammation, but it may also contribute to airway remodeling in allergic asthma in mice.

Seawater aspiration‑induced acute lung injury (ALI) is a syndrome associated with a high mortality rate, which is characterized by severe hypoxemia, pulmonary edema and inflammation. The present study is the first, to the best of our knowledge, to analyze gene expression profiles from a rat model of seawater aspiration‑induced ALI. Adult male Sprague‑Dawley rats were instilled with seawater (4 ml/kg) in the seawater aspiration‑induced ALI group (S group) or with distilled water (4 ml/kg) in the distilled water negative control group (D group). In the blank control group (C group) the rats' tracheae were exposed without instillation. Subsequently, lung samples were examined by histopathology; total protein concentration was detected in bronchoalveolar lavage fluid (BALF); lung wet/dry weight ratios were determined; and transcript expression was detected by gene sequencing analysis. The results demonstrated that histopathological alterations, pulmonary edema and total protein concentrations in BALF were increased in the S group compared with in the D group. Analysis of differential gene expression identified up and downregulated genes in the S group compared with in the D and C groups. A gene ontology analysis of the differential gene expression revealed enrichment of genes in the functional pathways associated with neutrophil chemotaxis, immune and defense responses, and cytokine activity. Kyoto Encyclopedia of Genes and Genomes analysis revealed that the cytokine‑cytokine receptor interaction pathway was one of the most important pathways involved in seawater aspiration‑induced ALI. In conclusion, activation of the cytokine‑cytokine receptor interaction pathway may have an essential role in the progression of seawater aspiration‑induced ALI, and the downregulation of tumor necrosis factor superfamily member 10 may enhance inflammation. Furthermore, IL‑6 may be considered a biomarker in seawater aspiration‑induced ALI.

The present study aimed to investigate the effects of sufentanil on sepsis-induced acute lung injury (ALI), and identify the potential molecular mechanisms underlying its effect. In order to achieve this, a rat sepsis model was established. Following treatment with sufentanil, the lung wet/dry (W/D) weight ratio was calculated. Histopathological analysis was performed via hematoxylin and eosin staining. Levels of inflammatory factors in bronchoalveolar lavage fluid were determined via ELISA. Furthermore, malondialdehyde (MDA) content and the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) in tissue homogenates were assessed using commercial kits. Western blot analysis was performed to determine kininogen-1 (KNG1) protein expression. In addition, alveolar epithelial type II cells (AEC II) were stimulated with lipopolysaccharide (LPS) to mimic ALI. The levels of inflammation and oxidative stress were evaluated following overexpression of KNG1. Protein expression levels of nuclear factor-κB (NF-κB) and nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling were determined via western blot analysis. The results of the present study demonstrated that sufentanil alleviated histopathological injury and the W/D ratio in lung tissue. Following treatment with sufentanil, levels of inflammatory factors also decreased, accompanied by decreased concentrations of MDA, and increased activities of SOD, CAT and GSH-Px. Notably, KNG1 was decreased in lung tissues following treatment with sufentanil. Furthermore, overexpression of KNG1 attenuated the inhibitory effects of sufentanil on LPS-induced inflammation and oxidative stress in AEC II. Sufentanil markedly downregulated NF-κB expression, while upregulating Nrf2 and HO-1 expression levels, which was reversed following overexpression of KNG1. Taken together, the results of the present study suggested that sufentanil may alleviate inflammation and oxidative stress in sepsis-induced ALI by downregulating KNG1 expression.

Mycoplasma pneumoniae (MP) is a common pathogen that can cause respiratory infections. MP pneumonia (MPP) leads to numerous complications, including lung injury and even death. The present study aimed to investigate the protective effects of Baicalin treatment on MP infection‑induced lung injury and the molecular mechanism underlying these effects. Briefly, after mice were infected intranasally by MP and treated with Baicalin (80 mg/kg), serum levels of MP‑immunoglobulin M (IgM) were detected by ELISA. The expression levels of C‑reactive protein (CRP) in lung tissue were detected by immunohistochemistry and the bronchoalveolar lavage fluid (BALF) was examined by ELISA. Inflammatory factors and inflammatory cells in the BALF were assessed. The expression levels of microRNA (miR)‑221 in lung tissue were examined by reverse transcription‑quantitative PCR and pathological changes in lung tissue were detected by H&E staining. Cell apoptosis was evaluated by TUNEL assay and the protein expression levels of TLR4, MyD88 and NF‑κB were detected by western blotting. Baicalin treatment significantly reduced serum levels of MP‑IgM and CRP expression in lung tissue during MP infection. In addition, Baicalin decreased the levels of IL‑1β, IL‑6, IL‑18 and TNF‑α in the BALF, and the number of inflammatory cells. Baicalin also reduced the inflammatory infiltration in lung tissue induced by MP infection, improved the pathological changes detected in lung tissue, reduced apoptosis, and downregulated the protein expression levels of TLR4, MyD88 and NF‑κB. Furthermore, Baicalin treatment downregulated the expression of miR‑221 and the protective effects of Baicalin were attenuated by miR‑221 overexpression. In conclusion, Baicalin has a therapeutic effect on mice with MP infection‑induced lung injury, which may be related to inhibition of miR‑221 expression and regulation of the TLR4/NF‑κB signaling pathway.

Fennel, commonly used in traditional Chinese medicine, is known as Foeniculum vulgare Mill. And its clinical application has been shown to target many biological systems including gastroenterology, endocrinology, gynecology and respiratory. The main constituent of the fennel essential oil is trans‑anethole, which has been described to have anti‑inflammatory and antibacterial activities. The aim of the present study was to define the anti‑inflammatory influence in acute lung injury (ALI)‑bearing mice. For 3 days, ALI‑bearing mice were induced by lipopolysaccharide (LPS) suspension in normal saline (24 mg/kg). On the fourth day, the trans‑anethole was administrated (36.4, 72.8 or 145.6 mg/kg) as well as dexamethasone (5 mg/kg) once per day for 7 consecutive days in mice. Following the completion of drug administration mice were sacrificed. Hematoxylin and eosin staining was performed in the lung paraffin section, for comparisons between monocyte and eosinophil cells in bronchoalveolar lavage fluid. The relative gene expression of interleukin (IL)‑10 and IL‑17 was determined by reverse transcription‑quantitative polymerase chain reaction. These two cytokines and the proportion of T helper 17 (Th17) cells and T regulatory (Treg) cells were determined by flow cytometry. The main constituent of fennel, trans‑anethole, eliminated LPS‑induced histopathological changes, decreased the number of inflammatory cells and resulted in a notable reduction in IL‑17 mRNA expression. In addition, trans‑anethole increased IL‑10 mRNA expression in isolated lung tissues and resulted in a marked elevation in Treg cells and reduction in Th17 cells in spleen tissues. The results of the present study indicated that the main constituent of fennel, trans‑anethole may be an anti‑inflammation component, which influenced the regulation of Th17/Treg responses. Therefore, this medicinal herb may support a healing effect on diseases of inflammatory.

The 'exterior-interior relationship between the lung and the large intestine' is a classical basic theory in Traditional Chinese Medicine. The present study aimed to investigate the roles of the toll like receptor/nuclear factor‑κB (TLR/NF‑κB) signaling pathway in the mutual interactions between the lung and the large intestine. A rat model of allergic asthma complicated with intestinal flora disorder was established by oral administration of Candida albicans and intraperitoneal injection with ovalbumin. The number of inflammatory cells and expression levels immunoglobulin (Ig)E, secretory IgA, interleukin (IL)‑4 and interferon‑γ in serum and bronchoalveolar lavage fluid were subsequently measured. Bacterial colonies and expression of 16S ribosomal DNA were studied in feces samples and pathological alterations of lung tissues were identified. Furthermore, the expression levels of genes associated with the TLR/NF‑κB signaling pathway in the lung and intestinal tissues were determined by reverse transcription‑quantitative polymerase chain reaction. The results of the present study indicated that, in the rat model of allergic asthma complicated with intestinal flora disorder, the expression levels of IL‑4 and IgE, and the numbers of inflammatory cells and C. albicans increased, and marked inflammatory cell infiltration was observed in lung tissues, suggesting that the animal model was successfully established. Furthermore, the present results revealed the mRNA expression levels of genes associated with the TLR/NF‑κB signaling (including myeloid differentiation primary response 88, TNF receptor associated factor 6 and β‑arrestin) were upregulated in both of the lung and intestinal tissues of the model group rats. Collectively, the results demonstrated that the TLR/NF‑κB signaling may serve roles in the mutual interactions between the lung and the large intestine, and TLR and NF‑κB may be potential targets for the treatment of lung diseases complicated with intestinal disorders.

Fasudil, which is primarily prescribed to treat cerebral vasospasm, may also inhibit systemic inflammation and prevent sepsis‑induced acute lung injury (ALI) in rats, although the mechanisms remain elusive. The purpose of the present study was to investigate the role of the rhodopsin (Rho)/Rho‑associated protein kinase (ROCK) signaling pathway in the protective effects of fasudil on ALI in septic rats. A total of 60 Wistar rats were pretreated with fasudil (30 mg/kg) through intraperitoneal injections 1 h prior to cecal ligation and puncture. Administration of fasudil led to reductions in polymorphonuclear neutrophil counts, and the protein concentrations of tumor necrosis factor‑α, interleukin (IL)‑1β and IL‑6 in the bronchoalveolar lavage fluid of rats with sepsis‑induced ALI. The results demonstrated that fasudil decreased sepsis‑induced bacteremia. In addition, fasudil effectively reduced the Evans blue content, wet/dry lung weight ratio, lung injury score, and expression levels of malondialdehyde and myeloperoxidase. However, the superoxide dismutase activity in the lung tissue of the rats was increased. Activated caspase‑3 activity in lung tissue was reduced to 29% by fasudil. Furthermore, the expression of Rho and ROCK1 was significantly downregulated, and the phosphorylation of myosin phosphatase‑targeting subunit 1 in lung tissues was markedly decreased, whereas the protein expression levels of zonula occludens 1 were increased in fasudil‑treated rats (P<0.05). In the in vitro experiments, vascular endothelial growth factor, intracellular adhesion molecule 1 and vascular cell adhesion molecule 1 secreted from human pulmonary microvascular endothelial cells treated with lipopolysaccharide (LPS) were attenuated by fasudil. Fasudil also reduced the fluorescence intensity of filamentous actin induced by LPS. Taken together, the results of the present study demonstrated that fasudil was able to improve endothelial permeability and inhibit inflammation, oxidative stress and cellular apoptosis in order to alleviate ALI in septic rats through inhibition of the Rho/ROCK signaling pathway.

Idiopathic pulmonary fibrosis (IPF) is a chronic and irreversible interstitial lung disease with a poor prognosis and limited therapeutic options. Over the past decade, research efforts have focused on the pathogenetic mechanisms involved in this enigmatic lung disease. Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease often complicated by the development of interstitial lung disease (ILD), leading to high mortality and morbidity. Autophagy is a process regulating the turnover of subcellular components and organelles, and represents a major cellular homeostatic mechanism. Recent evidence suggests a role of autophagy and mitochondrial dysfunction in the development of IPF, focusing on lung fibroblasts and epithelial cells. The aim of this study was to examine the mRNA levels of molecules involved inthe autophagy pathway in bronchoalveolar lavage fluid (BALF)‑derived cellsfrom patients with IPF in comparison topatients with RA demonstrating lung involvement (ILD) by RT-qPCR. The significant upregulation of BECLIN1 was observed in patients with RA-ILD compared with those with IPF. Other genes involved in the autophagy pathway were also examined, such as Unc-51 like autophagy activating kinase 1 (ULK1), BCL2 interacting protein 3 (BNIP3) and p62. No differences in the mRNA expression levels of these genes were observed. As regards the selective degradation of mitochondria and mitophagy, similar PTEN-induced putative kinase 1 (PINK1) and PARKIN; E3 ubiquitin ligase (PRKN) expression, as well as PINK1 protein levels, were observed. On the whole, the findings of this study demonstrate an increased expression of BECLIN1 in BALF cells from patients with RA-ILD compared with those from patients with IPF, while similar levels in other key molecules implicating in the autophagy pathway were observed in patients with IPF and RA-ILD.

The cellular and molecular mechanisms via which MK2206, an AKT inhibitor, prevents the activation of AKT in toluene diisocyanate (TDI)‑induced asthma remain unclear. Thus, the present study aimed to evaluate the potential effects of MK2206 on airway AKT activation, inflammation and remodeling in a TDI‑induced mouse model of asthma. A total of 24 BALB/c mice were selected and randomly divided into untreated (AOO), asthma (TDI), MK2206 (TDI + MK2206), and dexamethasone (TDI + DEX) groups. Phosphorylated AKT (p‑AKT), total AKT, airway remodeling indices, α‑smooth muscle actin (α‑SMA) and collagen I levels in pulmonary tissue were measured using western blotting. Airway inflammation factors, including interleukin (IL)‑4, ‑5, ‑6, and ‑13 in bronchoalveolar lavage fluid (BALF) and IgE in serum, were determined using ELISA. Additionally, the airway hyperresponsiveness (AHR) and pulmonary pathology of all groups were evaluated. The results of the present study demonstrated that p‑AKT levels in lung protein lysate were upregulated, and neutrophil, eosinophil and lymphocyte counts were increased in the lungs obtained from the asthma group compared with the AOO group. Both MK2206 and DEX treatment in TDI‑induced mice resulted not only in the attenuation of AKT phosphorylation, but also reductions in neutrophil, eosinophil and lymphocyte counts in the lungs of mice in the asthma group. Consistently, increases in the levels of the inflammatory cytokines IL‑4, ‑5, ‑6 and ‑13 analyzed in BALF, and serum IgE in the TDI group were demonstrated to be attenuated in the TDI + MK2206 and TDI + DEX groups. Furthermore, α‑SMA and AHR were significantly attenuated in the TDI + MK2206 group compared with the TDI group. These results revealed that MK2206 not only inhibited AKT activation, but also served a role in downregulating airway inflammation and airway remodeling in chemical‑induced asthma. Therefore, the findings of the present study may provide important insight into further combination therapy.

Oxymatrine (OMT) is the primary active component of Sophora flavescens Ait., and is widely used for the treatment of diabetic complications. The present study aimed to investigate the effects of OMT on acute lung injury (ALI) in diabetic rats subjected to myocardial ischemia/reperfusion (I/R). ALI in a myocardial I/R model was established in streptozocin‑induced diabetic rats. Enzyme‑linked immunosorbent assays were used to evaluate the levels of creatine kinase isoenzyme MB and lactate dehydrogenase, and the inflammatory response was assessed via leukocyte counts and the levels of tumor necrosis factor (TNF)‑α, interleukin (IL)‑6 and IL‑8 in the bronchoalveolar lavage (BAL) fluid. Hematoxylin and eosin staining was used to determine pathological changes to the lung tissue, and the autophagy‑related proteins LC‑3II/LC‑3I, Beclin‑1, autophagy protein 5 (Atg5) and p62 were detected by western blotting. Diabetic rats subjected to myocardial I/R showed increased levels of ALI with a higher lung injury score and WET/DRY ratio, and lower partial pressure of oxygen. This was accompanied by aberrant autophagy, indicated by an increased LC‑3II/LC‑3I ratio, decreased p62 expression levels, increased Atg5 and beclin‑1 expression levels, decreased superoxide dismutase activity and increased 15‑F2t‑isoprostane formation in lung tissues, as well as increased levels of leukocytes, TNF‑α, IL‑6 and IL‑8 in the BAL fluid. Administration of the autophagy inducer rapamycin significantly accelerated these alterations, while the autophagy inhibitor 3‑Methyladenine exerted the opposite effects. These results indicated that diabetic lungs are more vulnerable to myocardial I/R, which was associated with aberrant autophagy. Furthermore, oxymatrine was observed to reverse and alleviate ALI in diabetic rats with myocardial I/R in a concentration‑dependent manner, the mechanism of which may be associated with the inhibition of autophagy.

T cell‑associated inflammation, particularly type 2 inflammation, has an important role in asthma pathogenesis, which is suppressed by regulatory T cells (Tregs). Proviral integration site for Moloney murine leukemia virus 2 (PIM2), a member off the serine/threonine kinase family, promotes the growth and survival of T cells and influences the function of Treg cells. However, whether PIM2 affects asthma pathogenesis remains unclear. Peripheral blood mononuclear cells and Treg cells from asthmatic and healthy subjects were obtained, and the expression level of PIM2 was measured by reverse transcription‑quantitative polymerase chain reaction and immunocytochemistry. In addition, BALB/c female mice sensitized and challenged by ovalbumin were used as an asthma model, and PIM2 inhibitor was injected during the challenge period to observe the effect of PIM2 on asthma. The asthma symptoms were recorded, and airway hyper‑responsiveness (AHR), expression levels of cytokines in the serum or bronchoalveolar lavage fluid (BALF), and the number of BALF leukocytes were evaluated. In addition, hematoxylin and eosin staining and immunohistochemistry of lung tissues was performed. The results demonstrated that PIM2 was overexpressed in patients with asthma in natural Treg cells. Inhibition of PIM2 attenuated asthma symptoms, and improved AHR and airway inflammation compared with asthmatic mice without inhibition of PIM2. In addition, expression levels of interleukin (IL)‑10 and forkhead box protein 3 (FOXP3) in BALF were increased following PIM2 inhibition (IL‑10, 470.3±21.78 vs. 533.7±25.55 pg/ml, P<0.05; FOXP3, 259±4.68 vs. 279.3±3.68 pg/ml; asthma and PIM2 inhibition groups, respectively; P<0.05). In conclusion, PIM2 may exhibit an important role in asthma pathogenesis and exacerbate AHR, airway inflammation and asthma symptoms. These effects of PIM2 may be dependent on Treg cells and the secretion of IL‑10 by Tregs. The results of the present study suggest that PIM2 may be a potential target molecule for asthma treatment.

Dendritic cells (DCs) have an important role in initiating and maintaining the immune inflammatory response in allergic asthma, and CC chemokine receptor 7 (CCR7) is directly involved in the pathogenesis of DC‑ and T cell‑mediated allergic asthma. The present study aimed to investigate the effects of CCR7 on DC‑mediated immune tolerance in allergic asthma. In the present study, bone marrow‑derived DCs were transfected with an adenovirus encoding the rat CCR7 gene or a short hairpin RNA targeting CCR7 (sh‑CCR7). Rats injected with DCs overexpressing CCR7 or presenting CCR7 knockdown were examined. After the rats were injected with DCs via the tail vein, bronchoalveolar lavage fluid was collected to assess its cellular composition. The protein expression levels of CCR7 in DCs were determined using immunohistochemistry and western blot analysis. The protein expression levels of interferon‑γ (IFN‑γ), interleukin‑4 (IL‑4), IL‑10, IL‑12, transforming growth factor‑β (TGF‑β) and immunoglobulin E (IgE) were determined by ELISA. Compared with the control group, the protein expression level of CCR7 was significantly higher in the CCR7 overexpression group and significantly lower in sh‑CCR7 group. Similarly, the number of DCs was higher in the CCR7 overexpression group and lower in the sh‑CCR7 group. The protein expression levels of IL‑10 and TGF‑β were significantly lower in the CCR7 overexpression group and higher in the sh‑CCR7 group. In addition, the expression levels of IL‑4, IL‑12, IFN‑γ and IgE were higher in the CCR7 overexpression group and lower in the sh‑CCR7 group. The present results suggested that the role of cytokines and IgE in immune inflammation and immune tolerance in allergic asthma may be associated with the expression level of CCR7 in DCs, suggesting that CCR7 may serve a role in DC‑mediated immune tolerance in allergic asthma.

The present study aimed to examine the effects of 2.5 µm particulate matter (PM2.5) on airway inflammation and to investigate the possible underlying mechanism. Specifically, the focus was on the imbalance of T helper (Th)1/Th2 cells and the dysregulated expression of transcription factors, including trans‑acting T cell‑specific transcription factor 3 (GATA3), runt‑related transcription factor 3 (Runx3) and T‑box transcription factor TBX21 (T‑bet). In this study, ambient PM2.5 was collected and analyzed, male BALB/c mice were sensitized and treated with PBS, ovalbumin (OVA), PM2.5 or OVA + PM2.5. The effects of PM2.5 alone or PM2.5 + OVA on immunopathological changes, the expression of transcription factors GATA3, Runx3 and T‑bet, and the imbalance of Th1/Th2 were investigated. It was found that PM2.5 + OVA co‑exposure significantly enhanced inflammatory cell infiltration, increased higher tracheal secretions in lung tissue and upregulated respiratory resistance response to acetylcholine compared with PM2.5 or OVA single exposure and control groups. In addition, higher protein and mRNA expression levels of Th2 inflammatory mediators interleukin (IL)‑4, IL‑5 and IL‑13 in bronchoalveolar lavage fluid were observed in PM2.5 + OVA treated mice, whereas the expression levels of GATA3 and STAT6 were exhibited in mice exposed to OVA + PM2.5 compared with the OVA and PM2.5 groups. By contrast, PM2.5 exposure decreased the protein and mRNA expression levels of Th1 cytokine interferon‑γ and transcription factors Runx3 and T‑bet, especially among asthmatic mice, different from OVA group, PM2.5 exposure only failed to influence the expression of T‑bet. To conclude, PM2.5 exposure evoked the allergic airway inflammation response, especially in the asthmatic mouse model and led to Th1/Th2 imbalance. These effects worked mainly by upregulating GATA3 and downregulating Runx3. These data suggested that Runx3 may play an important role in PM2.5‑aggravated asthma in BALB/c mice.

Vitamin D and its receptor have a protective effect on epithelial barriers in various tissues. Low levels of vitamin D are associated with numerous pulmonary diseases, including acute lung injury (ALI) and acute respiratory distress syndrome. The present study investigated whether the vitamin D/vitamin D receptor (VDR) pathway may ameliorate lipopolysaccharide (LPS)‑induced ALI through maintaining the integrity of the alveolar epithelial barrier. This was investigated by exposing wild‑type (WT) and VDR knockout C57BL/6J mice to LPS, then comparing the healthy and LPS‑treated mice lungs and bronchoalveolar lavage fluid (BALF). More specifically, lung histology, mRNA levels of proinflammatory cytokines and chemokines, and protein expression levels of tight junction proteins were determined. In addition, a vitamin D analog (paricalcitol) was administered to WT mice in order to investigate the effect of vitamin D on the alveolar epithelial barrier following exposure to LPS. VDR knockout mice exhibited severe lung injuries (P<0.001), increased alveolar permeability [demonstrated by a higher wet‑dry ratio of lung weight (P<0.05), greater expression levels of BALF protein (P<0.001) and fluorescein isothiocyanate‑conjugated 4 kDa dextran (P<0.001) leakage into the alveolar space], elevated proinflammatory cytokine and chemokine mRNA levels, as demonstrated by reverse transcription‑quantitative polymerase chain reaction (P<0.05), and decreased protein and mRNA expression levels of occludin (P<0.01) and zonula occludens‑1 (ZO‑1; P<0.01) compared with WT mice. Paricalcitol treatment partially inhibited these pathological changes in WT mice by maintaining the mRNA and protein expression levels of occludin (P<0.01) and ZO‑1 (P<0.05). A lack of VDRs in the pulmonary epithelial barrier appeared to compromise its defense, leading to more severe LPS‑induced lung injury. Furthermore, vitamin D treatment alleviated LPS‑induced lung injury and preserved alveolar barrier function. Therefore vitamin D treatment may present as a potential therapeutic strategy in ALI and acute respiratory distress syndrome.

The versican family is important in the modulation of inflammation, however, the role of versican V1 (V1) in lipopolysaccharide (LPS)-induced acute lung injury (ALI) and the underlying mechanisms remain to be elucidated. To investigate this, the present study performed experiments in male C57BL/6J mice, which were randomly divided into a normal control group (control; n=6), an LPS‑stimulated ALI group (LPS; n=6), a scramble small interfering (si)RNA group (scramble; n=6), a V1‑siRNA group (V1‑siRNA; n=6), a scramble siRNA and LPS‑stimulated group (scramble+LPS; n=6) and a V1‑siRNA and LPS‑stimulated group (V1‑siRNA+LPS; n=6). On day 1, the mice were anesthetized, and 5 nmol scramble siRNA or V1‑siRNA were administered intratracheally. On day 3, LPS (1 mg/kg) or phosphate‑buffered saline (50 µl per mouse) were injected intratracheally. All the mice were anesthetized and sacrificed on day 4, and samples were collected and analyzed. The mRNA and protein expression levels were examined using reverse transcription‑quantitative polymerase chain reaction analysis, immunohistochemical staining and western blot analysis. ALI was evaluated based on lung injury scores, cell counts and total protein concentrations in the bronchoalveolar lavage fluid (BALF). Inflammatory mediators were detected using an enzyme-linked immunosorbend assay. V1 was increased by LPS in the mouse ALI model, whereas specific V1 knockdown induced higher lung injury scores, and higher total cell counts and protein concentrations in the BALF. Tumor necrosis factor‑α (TNF)‑α was upregulated, and interleukin‑6 exhibited an increasing trend. The expression of toll-like receptor 2 (TLR2), but not TLR4, increased, and the nuclear factor (NF)‑κB pathway subunit, P65, was phosphorylated. Taken together, the expression of V1 was upregulated by LPS, and V1 inhibition resulted in the aggravation of LPS‑induced ALI via the activation of TLR2-NF-κB and release of TNF-α.

The present study aimed to investigate the role of Bruton's tyrosine kinase (BTK) in the pathogenesis of lung injury induced by trauma‑hemorrhagic shock (THS), and to examine the pulmonary protective effects of BTK inhibition. Male Sprague‑Dawley rats were divided into four groups (n=12/group): i) A Sham group, which received surgery without induced trauma; ii) a THS‑induced injury group; iii) a THS‑induced injury group that also received treatment with the BTK inhibitor LFM‑A13 prior to trauma induction; and iv) a Sham group that was pretreated with LFM‑A13 prior to surgery but did not receive induced trauma. The expression of phosphorylated‑BTK protein in the lungs was measured by immunohistochemistry and western blot analysis. The bronchoalveolar lavage fluid (BALF) protein concentration, total leukocyte and eosinophil numbers, and the expression levels of peripheral blood proinflammatory factors were measured. Morphological alterations in the lungs were detected by hematoxylin and eosin staining. Pulmonary nitric oxide (NO) concentration and inducible NO synthase (iNOS) expression were also assessed. Activities of the nuclear factor (NF)‑κB and mitogen‑activated protein kinase (MAPK) signaling pathways were determined by western blotting or electrophoretic mobility shift assay. BTK was notably activated in lungs of THS rats. BALF protein concentration, total leukocytes and eosinophils, peripheral blood expression levels of tumor necrosis factor‑α, interleukin (IL)‑1β, IL‑6 and monocyte chemotactic protein 1 were significantly upregulated after THS induction, and each exhibited decreased expression upon LFM‑A13 treatment. THS‑induced interstitial hyperplasia, edema and neutrophilic infiltration in lungs were improved by the inhibition of BTK. In addition, THS‑induced NO release, iNOS overexpression, and NF‑κB and MAPK signaling were suppressed by BTK inhibition. Results from the present study demonstrate that BTK may serve a pivotal role in the pathogenesis of THS‑related lung injury, and the inhibition of BTK may significantly alleviate THS‑induced lung damage. These results provide a potential therapeutic application for the treatment of THS‑induced lung injury.