Response Of Lung Tissue Research Articles

Response of rat lung tissue to short-term hyperoxia: a proteomic approach

An inspiratory oxygen fraction of 1.0 is often required to avoid hypoxia both in many pre- and in-hospital situations. On the other hand, hyperoxia may lead to deleterious consequences (cell growth inhibition, inflammation, and apoptosis) for numerous tissues including the lung. Whereas clinical effects of hyperoxic lung injury are well known, its impact on the expression of lung proteins has not yet been evaluated sufficiently. The aim of this study was to analyze time-dependent alterations of protein expression in rat lung tissue after short-term normobaric hyperoxia (NH). After approval of the local ethics committee for animal research, N = 36 Wistar rats were randomized into six different groups: three groups with NH with exposure to 100 % oxygen for 3 h and three groups with normobaric normoxia (NN) with exposure to room air (21 % oxygen). After the end of the experiments, lungs were removed immediately (NH0 and NN0), after 3 days (NH3 and NN3) and after 7 days (NH7 and NN7). Lung lysates were analyzed by two-dimensional gel electrophoresis (2D-GE) followed by peptide mass fingerprinting using mass spectrometry. Statistical analysis was performed with Delta 2D (DECODON GmbH, Greifswald, Germany; ANOVA, Bonferroni correction, p < 0.01). Biological functions of differential regulated proteins were studied using functional network analysis (Ingenuity Pathways Analysis, IPA). pO2 was significantly higher in NH-groups compared to NN-groups (581 ± 28 vs. 98 ± 12 mmHg; p < 0.01), all other physiological parameters did not differ. Expression of 14 proteins were significantly altered: two proteins were up-regulated and 12 proteins were down-regulated. Even though NH was comparatively short termed, significant alterations in lung protein expression could be demonstrated up to 7 days after hyperoxia. The identified proteins indicate an association with cell growth inhibition, regulation of apoptosis, and approval of structural cell integrity.

The oxidative damage and inflammatory response induced by lead sulfide nanoparticles in rat lung

Lead sulfide nanoparticles (PbS NPs) are one important nanoparticle materials which is widely used in photoelectric production, but its potential health hazard to respiratory system is not clear. This study aimed to explore the possible mechanism of lung injury induced by PbS NPs. Male SD rats were treated with nanoparticles of 60 nm and 30 nm lead sulfide. The main methods were detecting the vigor of superoxide dismutase (SOD) and total antioxidant capacity (T-AOC) and the content of malondialdehyde (MDA) in both blood and lung tissues and observing the pathological changes in lung tissue. PbS NPs suppressed the activity of SOD and T-AOC, and increased serum MDA content (P<0.05); both effects were observed together in lung tissues of 30-nm group (P<0.05) accompanied by an obviously inflammatory response. PbS NPs induced oxidative damage and inflammatory response in lung tissue, which may be an underlying mechanism for its pulmonary toxicity. Additionally, the toxicity of PbS NPs was closely related with the size of nanoparticles.

Unlipidated Outer Membrane Protein Omp16 (U-Omp16) from Brucella spp. as Nasal Adjuvant Induces a Th1 Immune Response and Modulates the Th2 Allergic Response to Cow’s Milk Proteins

The discovery of novel mucosal adjuvants will help to develop new formulations to control infectious and allergic diseases. In this work we demonstrate that U-Omp16 from Brucella spp. delivered by the nasal route (i.n.) induced an inflammatory immune response in bronchoalveolar lavage (BAL) and lung tissues. Nasal co-administration of U-Omp16 with the model antigen (Ag) ovalbumin (OVA) increased the amount of Ag in lung tissues and induced OVA-specific systemic IgG and T helper (Th) 1 immune responses. The usefulness of U-Omp16 was also assessed in a mouse model of food allergy. U-Omp16 i.n. administration during sensitization ameliorated the hypersensitivity responses of sensitized mice upon oral exposure to Cow’s Milk Protein (CMP), decreased clinical signs, reduced anti-CMP IgE serum antibodies and modulated the Th2 response in favor of Th1 immunity. Thus, U-Omp16 could be used as a broad Th1 mucosal adjuvant for different Ag formulations.

MAPK Kinase 3 Potentiates Chlamydia HSP60-Induced Inflammatory Response through Distinct Activation of NF-κB

Chlamydia pneumonia (C. pneumonia) remains one of the leading causes of bacterial pneumonia and has been implicated in the pathogenesis of some inflammation-related diseases, such as asthma, chronic obstructive pulmonary disease, and vascular diseases. Heat shock protein 60 is one of the pathogenic components of C. pneumonia that is closely associated with the inflammatory disorders. However, the molecular basis for the immunopathologic property of chlamydial heat shock protein (cHSP60) has not been elucidated. In this article, we report that MAPK kinase 3 (MKK3) is essential for cHSP60-induced lung inflammation, because MKK3-knockout mice displayed significantly reduced lung neutrophil accumulation and decreased production of proinflammatory mediators, correlating with the alleviated inflammatory response in lung tissues. Mechanistically, p38 kinase was selectively activated by MKK3 in response to cHSP60 and activated NF-κB by stimulating the nuclear kinase, mitogen- and stress-activated protein kinase 1. The specific knockdown of mitogen- and stress-activated protein kinase 1 in macrophages resulted in a defective phosphorylation of NF-κB/RelA at Ser(276) but had no apparent effect on RelA translocation. Furthermore, TGF-β-activated kinase 1 was found to relay the signal to MKK3 from TLR4, the major receptor that sensed cHSP60 in the initiation of the inflammatory response. Thus, we establish a critical role for MKK3 signaling in cHSP60 pathology and suggest a novel mechanism underlying C. pneumonia-associated inflammatory disorders.

Asian sand dust induces autophagic markers and activates NF-κB in immune cells (P6377)

Abstract It is well going to know that several particles modulate immune responses and phagocytosis may induce activation in antigen-presenting cells. Asian sand dust (ASD), which is derived from air pollutants in East China that migrate to Japan and ASD is concerned about influence for health. Our group has reported that ASD induced inflammatory responses in lung tissue and causes respiratory diseases in mice. In the last meeting, we reported that the effect of ASD on the immune system in vivo. In this study, we examined the effect of ASD in vitro. Cell lysates were prepared from freshly isolated splenocytes of ICR mice and resolved by western blotting. Immunoblotting demonstrated that ASD induced autophagic-marker LC3-II expression and decreased the level of p62 especially in CD11b+ cells. Cell activation of splenocytes was evaluated by a cell viability assay. The cell viability assay showed mitogen-induced proliferation of splenocytes is inhibited by ASD treatment. In addition, an electrophoretic mobility shift assay demonstrated increased activated-NF-κB in bone marrow derived macrophage after ASD treatment. Taken together, these results suggest that ASD activates immune cells, and may modulate cell survival or activity.

Effects of propofol versus sevoflurane combined with remifentanil anesthesia on activity of nuclear factor kappa B in neutrophil granulocyte during one-lung ventilation in patients undergoing radical resection of esophagus cancer

Objective To compare the effects of propofol versus sevoflurane combined with remifentanil anesthesia on the activity of nuclear factor-kappa B (NF-κB) in neutrophil granulocyte during one-lung ventilation (OLV) in patients undergoing radical resection of esophagus cancer.Methods Forty ASA physical status Ⅰ or Ⅱpatients of both sexes,aged 40-64 yr,with body mass index 18-25 kg/m2,undergoing radical resection of esophagus cancer,were randomized into 2 groups (n =20 each):propofol-remifentanil group (group P) and sevofluraneremifentanil group (group S).Anesthesia was induced with midazolam,sufentanil,etomidate and cisatracurium besylate in both groups.The patients were tracheal intubated and mechanically ventilated.Anesthesia was maintained with iv infusion of propofol 4-8 mg· kg-1 · min-1 in group P,or with inhalation of 1%-3% sevoflurane in group S,and with iv infusion of remifentanil 0.2μg· kg-1 · min-1 and intermittent iv boluses of cisatracurium besylate 7 mg in both groups.The Narcotrend index value was maintained between 40 and 50.Blood samples were taken from the radial artery at 5 min after intubation,the beginning of OLV,30,60 and 90 min of OLV,0 and 10 min after re-expansion of the collapsed lung,and the end of surgery for blood gas analysis and for determination of plasma concentrations of IL-1.The oxygenation index and respiratory index were calculated.The nuclear protein of neutrophil granulocytes was extracted for detection of NF-κB-DNA binding activity.Results Compared with group P,the respiratory index,plasma concentrations of IL-1 and NF-κB-DNA binding activity were significantly increased (P ＜ 0.05),and no significant change was found in the oxygenation index in group S (P ＞ 0.05).Conclusion Compared with sevoflurane-remifentanil anesthesia,propofol-remifentanil anesthesia can inhibit activation of NF-κB in neutrophil granulocyte and is helpful in attenuating the inflammatory response in lung tissues during OLV in patients undergoing radical resection of esophagus cancer. Key words: Propofol ; Anesthetics, inhalation ; Piperidines ; Respiration, artificial; NF-kappa B ; Neutrophils

Abstract 2907: Role of reactive oxygen and nitrogen species in resveratrol-induced lung cancer cell death.

Abstract Lung cancer is the leading cause of cancer related deaths worldwide. In 2008, 158,592 deaths were attributed to this disease and 208,493 new cases were diagnosed in the United States. Resveratrol (trans-3, 5, 4′-trihydroxystilbene), a compound found largely in the skins of red grapes, has been reported to be a promising anticancer agent in various types of cancer. The primary goal of this study is to delineate the key signaling pathways induced in response to resveratrol leading to lung cancer cell death. In this study, we use non-tumorigenic human bronchial epithelial (BEAS-2B) and human lung epithelial cancer (H460) cells to model the response of lung tissue to resveratrol. We observed an increase in superoxide, hydrogen peroxide and nitric oxide production in response to resveratrol treatment in lung cancer cells (H460) as compared to non-tumorigenic cells (BEAS-2B). Additionally, our data shows an increase in BEAS-2B cell viability as compared to H460 cell viability in response to resveratrol treatment. Overall, we observe an increase in cellular oxidative and nitrosative stress in cancer cells in response to resveratrol treatment which may be responsible for increased apoptosis and decreased viability in these cells. Subsequently, we plan to identify the specific reactive species as well as the major apoptotic pathway induced in response to resveratrol treatment in both normal and cancer cells. We expect resveratrol to have significant effect on lung cancer cells via oxidative/nitrosative stress-mediated modulation of key apoptotic biomarkers. This study will establish the protective role of resveratrol in the pathogenesis of lung cancer and the information can be potentially exploited to improve future lung cancer therapies. Citation Format: Elizabeth S. Monillas, Grayson Walker, Aubrey Brockmiller, Anand Iyer, Neelam Azad. Role of reactive oxygen and nitrogen species in resveratrol-induced lung cancer cell death. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2907. doi:10.1158/1538-7445.AM2013-2907

Antenatal betamethasone attenuates intrauterine infection-aggravated hyperoxia-induced lung injury in neonatal rats

Intrauterine infection can exacerbate postnatal hyperoxic lung injury. We hypothesized that antenatal betamethasone treatment attenuates hyperoxic lung injury aggravated by intrauterine infection in neonatal rats. Newborn Sprague-Dawley rats were divided into eight experimental groups according to (i) whether rats were exposed to normoxia (N) or hyperoxia (H, 85% oxygen) from postnatal day (P)1 to P14, (ii) whether antenatal betamethasone (0.2 mg/dose) or vehicle was administered to pregnant rats at gestation days (E)19 and E20, and (iii) whether intrauterine infection was induced or not antenatally. Intrauterine infection was induced by intracervical inoculation of Escherichia coli into pregnant rats on E19. We measured cytokine levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-6, and IL-1β in P1 rat lungs and performed morphometric analyses and assessed inflammatory responses in lung tissue and bronchoalveolar lavage (BAL) at P14 by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL) staining and measurement of myeloperoxidase activity, collagen, and cytokine levels. Cytokine levels in P1 rat lungs were increased by intrauterine infection, and these increases were attenuated by antenatal betamethasone. Hyperoxic lung injuries, indicated by morphometric changes and an inflammatory response in the lung and BAL fluid, were aggravated by intrauterine infection at P14. This aggravation was significantly attenuated by antenatal betamethasone. Antenatal betamethasone attenuated aggravated hyperoxic lung injuries induced by intrauterine infection in neonatal rats via its anti-inflammatory actions.

Serum profiles of matrix metalloproteinases and their tissue inhibitors in long-term pulmonary complication induced by sulfur mustard: Sardasht-Iran Cohort Study (SICS)

Sulfur mustard (SM) is a cytotoxic chemical agent which can cause severe irritation and irreversible damages to body tissues. The effect of SM gas on respiratory tract is one of the main causes of short and long term disabling complications. Matrix metalloproteinases (MMPs) have a critical role in controlling extra cellular matrix remodeling and inflammatory responses in lung tissue and are involved in many various chronic pulmonary diseases. The aim of the present study was to evaluate the possible role of MMPs and their endogenous inhibitors in SM induced lung symptoms in exposed subjects 20 years after exposure. Serum level of MMP-1, MMP-2, MMP-8, MMP-9, TIMP-1, TIMP-2, TIMP-3, and TIMP-4 was measured by ELISA and compared between groups of exposed without any symptoms (control group) and with mild or moderate-severe lung complications. MMP-2 and MMP-9 activity was assayed by gelatin zymography method. There was a significant association between serum level of MMP-1 and severity of lung complications in SM exposed groups. MMP-2 activity was decreased in exposed groups with mild lung complications. TIMPs level was not different in exposed and normal groups. We concluded that increased serum levels of MMP-1 and decreased MMP-2 activity may have roles in pathogenesis and persistence of lung complications in SM exposed victims.

MiR-638 regulates gene expression networks associated with emphysematous lung destruction

BackgroundChronic obstructive pulmonary disease (COPD) is a heterogeneous disease characterized by varying degrees of emphysematous lung destruction and small airway disease, each with distinct effects on clinical outcomes. There is little known about how microRNAs contribute specifically to the emphysema phenotype. We examined how genome-wide microRNA expression is altered with regional emphysema severity and how these microRNAs regulate disease-associated gene expression networks.MethodsWe profiled microRNAs in different regions of the lung with varying degrees of emphysema from 6 smokers with COPD and 2 controls (8 regions × 8 lungs = 64 samples). Regional emphysema severity was quantified by mean linear intercept. Whole genome microRNA and gene expression data were integrated in the same samples to build co-expression networks. Candidate microRNAs were perturbed in human lung fibroblasts in order to validate these networks.ResultsThe expression levels of 63 microRNAs (P < 0.05) were altered with regional emphysema. A subset, including miR-638, miR-30c, and miR-181d, had expression levels that were associated with those of their predicted mRNA targets. Genes correlated with these microRNAs were enriched in pathways associated with emphysema pathophysiology (for example, oxidative stress and accelerated aging). Inhibition of miR-638 expression in lung fibroblasts led to modulation of these same emphysema-related pathways. Gene targets of miR-638 in these pathways were amongst those negatively correlated with miR-638 expression in emphysema.ConclusionsOur findings demonstrate that microRNAs are altered with regional emphysema severity and modulate disease-associated gene expression networks. Furthermore, miR-638 may regulate gene expression pathways related to the oxidative stress response and aging in emphysematous lung tissue and lung fibroblasts.

CCAAT/Enhancer-Binding Protein δ Is a Critical Mediator of Lipopolysaccharide-Induced Acute Lung Injury

Although inflammation plays a central role in the pathogenesis of acute lung injury, the molecular mechanisms underlying inflammatory responses in acute lung injury are poorly understood, and therapeutic options remain limited. CCAAT/enhancer-binding proteins, C/EBPβ and C/EBPδ, are expressed in the lung and have been implicated in the regulation of inflammatory mediators. However, their functions in lung pathobiological characteristics are not well characterized. Herein, we show that C/EBPβ and C/EBPδ are activated in mouse lung after intrapulmonary deposition of lipopolysaccharide (LPS). Mice carrying a targeted deletion of the C/EBPδ gene displayed significant attenuation of the lung permeability index (lung vascular leak of albumin), lung neutrophil accumulation (myeloperoxidase activity), and neutrophils in bronchial alveolar lavage fluids compared with wild-type mice. These phenotypes were consistent with morphological evaluation of lung, which showed reduced inflammatory cell influx and minimal intra-alveolar hemorrhage. Moreover, mutant mice expressed considerably less tumor necrosis factor-α, IL-6, and macrophage inflammatory protein-2 in bronchial alveolar lavage fluids in LPS-injured lung compared with wild-type mice. In contrast, C/EBPβ deficiency had no effect on LPS-induced lung injury. By using small-interfering RNA-mediated knockdown for C/EBPδ, we demonstrate, for the first time to our knowledge, that C/EBPδ plays a critical role for the tumor necrosis factor-α, IL-6, and macrophage inflammatory protein-2 production in LPS-stimulated alveolar macrophages. These findings demonstrate that C/EBPδ, but not C/EBPβ, plays an important role in LPS-induced lung inflammatory responses and injury.

High Strain Rate Pure Shear and Axial Compressive Response of Porcine Lung Tissue

In this study, both the dynamic shear (torsion) and axial compressive responses of porcine lung tissue were examined using modified Kolsky bar techniques. High-rate compression data were collected using a Kolsky bar with a hollow transmission bar on annular specimens at strain rates between 1000–3000 s−1. The radial deformation of the annular specimen was recorded on a modified single loading Kolsky bar using high-speed imaging capabilities. The collected images and analysis of boundary movement indicated inhomogeneous specimen deformation induced by radial inertia, which significantly altered the desired uniaxial stress state in such high-rate compression test techniques. A novel torsion experimental technique was developed to obtain the dynamic pure shear behavior of lung tissue at shear strain rates above 500 s−1 without inertia effects. The pure shear response was found to be two orders of magnitude weaker than the uniaxial compressive response when compared by equivalent stress–strain relations.

Lung T-cell responses to nontypeable Haemophilus influenzae in patients with chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is characterized by pulmonary inflammation that persists after the cessation of smoking. T cells have a major role in driving inflammation in patients with COPD and are activated by specific antigens to produce mediators, such as cytokines. The antigens that activate lung T cells have not been clearly defined. Nontypeable Haemophilus influenzae (NTHi) is the dominant bacterium isolated from the lungs of patients with COPD. We sought to measure the response of lung tissue T cells to stimulation with NTHi. We obtained lung tissue from 69 subjects having lobectomies for lung cancer. Of the group, 39 subjects had COPD, and 30 without COPD were classified as control subjects. The lung tissue was dispersed into single-cell suspensions and stimulated with live NTHi. Cells were labeledwith antibodies for 5 important inflammatory mediators in patients with COPD and analyzed by using flow cytometry. NTHi produced strong activation of both TH cells and cytotoxic T cells in the COPD cohort. The COPD cohort had significantly higher levels of cells producing TNF-α, IL-13, and IL-17 in both T-cell subsets. When control subjects were divided into those with and without a significant smoking history and compared with patients with COPD, there was a progressive increase in the numbers of T cells producing cytokines from nonsmoking control subjects to smoking control subjects to patients with COPD. NTHi activates lung T cells in patients with COPD. This proinflammatory profibrotic response might be a key cause of inflammation in patients with COPD and has implications for treatment.

Detection and Early Phase Assessment of Radiation-Induced Lung Injury in Mice Using Micro-CT

Radiation therapy is an important therapeutic modality for thoracic malignancies. However, radiation-induced pulmonary injuries such as radiation pneumonitis and fibrosis are major dose-limiting factors. Previous research shows that micro-computed tomography (micro-CT) can detect radiation-induced lung injuries a few months following irradiation, but studies to assess the early response of lung tissue are lacking. The aim of this study was to determine if micro-CT could be used to detect and assess early-phase radiation–induced lung injury in mice. Twenty-one animals were divided into three groups: normal (n = 7), one day after x-ray exposure (n = 7), and at four days after x-ray exposure (n = 7). The x-ray-exposed groups received a single dose of 20 Gy, to the whole lung. Histology showed enlargements of the air space (Lm: mean chord length) following irradiation. 40.5±3.8 µm and 60.0±6.9 µm were observed after one and four days, respectively, compared to 26.5±3.1 µm in normal mice. Three-dimensional micro-CT images were constructed and histograms of radiodensity - Hounsfield Units (HU) - were used to assess changes in mouse lungs. Radiation-induced lung injury was observed in irradiated mice, by the use of two parameters which were defined as shifts in peak HU between −200 to −800 HU (PeakHU) and increase in the number of pixels at −1000 HU (Number-1000). These parameters were correlated with histological changes. The results demonstrate that micro-CT can be used for the early detection and assessment of structural and histopathological changes resulting from radiation-induced lung injury in mice. Micro-CT has the advantage, over traditional histological techniques, of allowing longitudinal studies of lung disease progression and assessment of the entire lung, while reducing the number of animals required for such studies.

Effects of Xinfeng capsule on pulmonary function based on treg-mediated notch pathway in a rat model of adjuvant arthritis

ObjectiveTo observe the impact of xinfeng xapsule (XFC) on pulmonary function in a rat model of adjuvant arthritis (AA) and to investigate the mechanism of action. MethodsForty rats were randomly divided into four groups of ten: normal control (NC); model control (MC); tripterygium glycosides tablet (TPT); and xinfeng capsule (XFC). Except for the NC group, AA was induced in all rats by intracutaneous injection of 0.1 mL Freund's complete adjuvant in the right paw on the 19th day. NC and MC groups were given (0.9%) physiological saline. The TPT and XFC groups were given TPT (10 mg/kg) and XFC (1.2 g/kg), respectively. Thirty days after administration, changes in paw edema (E), the arthritis index (AI), pulmonary function, levels of regulatory T-cells (Treg), ultrastructure of lung tissue, and expression of Notch receptors and ligands in lung tissue were observed. ResultsIn the MC group, E and the AI were increased and pulmonary function significantly decreased; the structure of alveolar type-II cells was damaged; ratios of Treg in peripheral blood were reduced; and expression of Notch receptors such as Notch3 and Notch4 and ligands such as Delta1 in lung tissue were significantly increased whereas expression of Notch1, Jagged1 and Jagged2 were significantly decreased. After intervention with XFC, E and the AI were decreased; pulmonary function was enhanced; the structure of alveolar type-II cells was improved; and expression of Treg, Notch1, Jagged1, Jagged2 was elevated, whereas that of Notch3, Notch4 and Delta1 was reduced. ConclusionXFC can not only inhibit E and the AI and improve joint symptoms, it can also improve pulmonary function and reduce inflammation in lung tissue. These actions could be carried out through increases in the expression of Treg, Notch receptors (Notch1) and ligands (Jagged1, Jagged2), and reductions in the expression of Notch3, Notch4 and Delta1. These phenomena would reduce the deposition of immune complexes and the inflammatory response in lung tissue, thereby improving joint symptoms and pulmonary function.

The Influence of Cigarette Smoke on the Selected Bronchoalveolar Cells in Experiment

The occurence of lung diseases (obstructive, malignant) resulting from smoking has an increasing tendency. The lung is the primary organ at risk from the effects of inhaled cigarette smoke and smoking has been implicated as a contributing factor to the causation of various respiratory diseases. The aim of presented work was to find out the subchronic effect of the 6-month exposure to cigarette smoke on the selected inflammatory and cytotoxic parameters of bronchoalveolar lavage in W rats and thus to contribute to understanding of the mechanism of action of tobacco smoke and/or path mechanism of lung injury developed after cigarette smoking. In special chamber, the animals smoked 8 standard research 1R1 type of cigarettes per day, except Saturdays and Sundays, during 6 months. The daily concentration of total particulate matter (TPM)/m3 air for two hours per exposure requiring to burn eight cigarettes was 85 mg. Animals were sacrificed after the 6-month exposure and bronchoalveolar lavage (BAL) was performed and selected inflammatory and cytotoxic BAL parameters were examined and compared with the control group. Following BAL parameters were investigated: the total cell and alveolar macrophages (AM) count in BAL, the differential cell count (% of AM, % of polymorphonuclears--PMN, % of lymphocytes--Ly), proportion of immature AM, proportion of bi-nucleated cells--BNC, viability, the phagocytic activity of AM, cytokines TNF-alpha (tumor necrosis factor alpha) and IL-1beta (interleukin-1beta). A) The 6-month smoking of eight cigarettes daily significantly changed prevailing number of examined BAL parameters; B) The presence of inflammatory and cytotoxic responses in lung tissue can probably signalize beginning or developing of disease process.

Viable Alternatives to in vivo Tests for Evaluating the Toxicity of Engineered Carbon Nanotubes

Carbon nanotubes (CNTs) stand at the frontier of nanotechnology and are destined to stimulate the next industrial revolution. Rapid increase in their production and use in the technology industry have led to concerns over the effects of CNT on human health and the environment. The prominent use of CNTs in biomedical applications also increases the possibility of human exposure, while properties such as their high aspect ratio (fiber-like shape) and large surface area raise safety concerns for human health if exposure does occur. It is crucial to develop viable alternatives to in vivo tests in order to evaluate the toxicity of engineered CNTs and develop validated experimental models capable of identifying CNTs' toxic effects and predicting their level of toxicity in the human respiratory system. Human lung epithelial cells serve as a barrier at the interface between the surrounding air and lung tissues in response to exogenous particles such as air-pollutants, including CNTs. Monolayer culture of the key individual cell types has provided abundant fundamental information on the response of these cells to external perturbations. However, such systems are limited by the absence of cell-cell interactions and their dynamic nature, which are both present in vivo. In this review, we suggested two viable alternatives to in vivo tests to evaluate the health risk of human exposure to CNTs.

Abstract A32: Mechanistic Dissection of Lung Cancer Promotion by Airway Inflammation

Abstract Cigarette smoking is the principal cause of lung carcinogenesis, however, smokers with chronic obstructive pulmonary disease (COPD) have an increased risk of lung cancer (3 to 10 fold) compared to smokers with comparable cigarette exposure but without COPD. Histopathologic studies have clearly demonstrated lung inflammation in COPD, and it persists even after cessation of cigarette smoking. These facts suggest a strong link between COPD-related airway inflammation and lung cancer promotion independent of smoking but the precise mechanistic link is not known. We developed a COPD-like mouse model of airway inflammation through repeated aerosol challenge to a lysate of non-typeable Haemophilus influenzae (NTHi) which commonly colonizes the airways of COPD patients. Then, we showed that this type of airway inflammation, but not asthma-like airway inflammation, promotes lung cancer in a K-ras mutant mouse model of lung cancer (CC-LR). This was associated with NF-kB pathway activation, and up-regulation of its downstream target genes, including IL-6 and T helper 17 (Th17) response. Therefore, we studied the role of NF-kB in lung cancer promotion by targeting its expression in airway epithelium. CC-LR mice were crossed with IKK-βf/f mice to develop a mouse with lack of NF-kB activity in airway secretory cells (CC-LR-IKKβ mice). NF-kB deficiency in the airway epithelium changed the bronchoalveolar lavage fluid (BALF) cellular component (mostly reduction in macrophage number) of the CC-LR mice, and resulted in a ∼70% (3.4-fold) reduction in lung surface tumor number compared to age and sex matched control CC-LR mice. It also significantly reduced the number of visible tumors on the lung surface of the CC-LR mice by &amp;gt;60% (2.6-fold) after inducing COPD-like airway inflammation using weekly NTHi exposure for 8 weeks. We then genetically ablated IL-6 in the CC-LR mice. Lack of IL-6 did not change the BALF inflammatory cell component of the CC-LR mice. However, it not only inhibited intrinsic lung cancer development (1.7-fold, 41%), but also inhibited the promoting effect of extrinsic NTHi-induced COPD-like airway inflammation (2.6-fold, 62%) on lung carcinogenesis, suggesting a role for IL-6 mediated epithelial cell signaling in tumor promotion by COPDlike airway inflammation. This is under further investigation by our group. IL-6 is required for differentiation of Th17 cells from naive T cells. Th17 cells mostly produce IL-17A, and IL-17F. These both bind to the IL-17 receptor (IL-17R), and IL-17R signaling is required for lung CXC chemokine expression and neutrophil recruitment, however, we found that only the IL-17R KO and IL-17A KO but not IL-17F KO mice showed lower levels of neutrophilic influx into the BALF and less inflammatory cell infiltration in lung tissue in response to NTHi. Furthermore, IL-17A induces more production of IL-6 by epithelial cells. So, CC-LR mice were crossed with IL-17A KO mice. Lack of IL-17A resulted in a ∼70% (3.4-fold) reduction in lung surface tumor number compared to age and sex matched control CC-LR mice. It also significantly reduced the number of visible tumors on the lung surface of the CCLR mice by ∼54% (2.2-fold) after inducing COPD-like airway inflammation using weekly NTHi exposure for 4 weeks from the age of 10 weeks. We conclude that airway inflammation through NF-kB mediated activation of the IL-6/Th17 signaling pathway promotes lung carcinogenesis.

Changes of CD4(+) CD25(+) Regulatory T Cells, FoxP3 in Adjuvant Arthritis Rats with Damage of Pulmonary Function and Effects of Tripterygium Glycosides Tablet.

Objective. To observe the effects of tripterygium glycosides tablet (TPT) on swelling degree, arthritis index (AI), pulmonary function, cytokines, the expression of regulatory T cells (Treg), and Foxp3 in rats of adjuvant arthritis. Methods. Rats were averagely divided into normal control (NC) group, model control (MC) group, methotrexate (MTX) group, and tripterygium glycosides tablet (TPT) group. Except for the rats of normal group, the others were intracutaneously injected with 0.1 mL of Freund's complete adjuvant in the right hindlimb. NC group and MC group were treated with physiological saline. MTX group and TPT group were treated with MTX, TPT, respectively. Results. The levels of swelling degree, AI, the alveolar inflammation integral, TNF alpha (TNF-α), and endothelium-1 (ET-1 ) in MC group were significantly increased (P < 0.01), and the levels of forced vital capacity (FVC), 25% vital capacity of the peak expiratory flow (FEF25), 50% vital capacity of the peak expiratory flow (FEF50), 75% vital capacity of the peak expiratory flow (FEF75), maximum midexpiratory flow (MMF), peak expiratory flow (PEF), interleukin-10 (IL-10), CD4+ CD25+ Treg, and Foxp3 were decreased (P < 0.01). The scores of alveolitis and ET-1 were decreased with treatment of TPT. The levels of FVC, FEF25, FEF50, FEF75, MMF, PEF, IL-10, and CD4+ CD25+ Treg in peripheral blood were increased. The expressions of Foxp3 protein and mRNA in lung tissue were also increased in TPT group. Conclusions. The paw swelling can be inhibited by TPT, and the inflammatory response in lung tissue was also decreased, which is a significant improvement in pulmonary function. The mechanism is probably associated with upregulating the expression of IL-10, Foxp3, and downregulating the level of TNF-α.

Transient Receptor Potential Vanilloid-1 (TRPV1) Is a Mediator of Lung Toxicity for Coal Fly Ash Particulate Material

Environmental particulate matter (PM) pollutants adversely affect human health, but the molecular basis is poorly understood. The ion channel transient receptor potential vanilloid-1 (TRPV1) has been implicated as a sensor for environmental PM and a mediator of adverse events in the respiratory tract. The objectives of this study were to determine whether TRPV1 can distinguish chemically and physically unique PM that represents important sources of air pollution; to elucidate the molecular basis of TRPV1 activation by PM; and to ascertain the contributions of TRPV1 to human lung cell and mouse lung tissue responses exposed to an insoluble PM agonist, coal fly ash (CFA1). The major findings of this study are that TRPV1 is activated by some, but not all of the prototype PM materials evaluated, with rank-ordered responses of CFA1 > diesel exhaust PM > crystalline silica; TRP melastatin-8 is also robustly activated by CFA1, whereas other TRP channels expressed by airway sensory neurons and lung epithelial cells that may also be activated by CFA1, including TRPs ankyrin 1 (A1), canonical 4α (C4α), M2, V2, V3, and V4, were either slightly (TRPA1) or not activated by CFA1; activation of TRPV1 by CFA1 occurs via cell surface interactions between the solid components of CFA1 and specific amino acid residues of TRPV1 that are localized in the putative pore-loop region; and activation of TRPV1 by CFA1 is not exclusive in mouse lungs but represents a pathway by which CFA1 affects the expression of selected genes in lung epithelial cells and airway tissue.