Degree Of Lung Inflammation Research Articles

Recombinant Art v4.01 protein produces immunological tolerance by subcutaneous immunotherapy in a wormwood pollen-driven allergic asthma female mouse model.

Art v4.01 is a well-known profilin protein belonging to the pan-allergens group and is commonly involved in triggering allergic asthma, polyallergy, and cross-sensitization. It is also referred to as Wormwood due to its origin. Crude wormwood extracts are applied for allergen-specific immunotherapy (AIT). Whether the recombinant Art v4.01 (rArt v4.01) can produce in vivo immunological tolerance by subcutaneous immunotherapy (SCIT) remains elusive. In this study, to investigate the in vivo immunological response of rArt v4.01, Th2, Th1, Treg, Th17 type-related cytokines and phenotypes of immune cells were tested, facilitating the exploration of the underlying mechanisms. The expression and purification of Art v4.01 were carried out using recombinant techniques. Allergic asthma female BALB/c mice were induced by subcutaneous sensitization of wormwood pollen extract and intranasal challenges. SCIT without adjuvant was performed using the rArt v4.01 and wormwood pollen extract for 2 weeks. Following exposure to challenges, the levels of immunoglobulin E (IgE), cytokines, and inflammatory cells were assessed through enzyme-linked immunosorbent assay (ELISA) and histological examination of sera, bronchoalveolar lavage fluid (BALF), and lung tissue. These parameters were subsequently compared between treatment groups receiving rArt v4.01 and wormwood pollen extract. The rArt v4.01 protein was expressed, which had a high purity (>90%) and an allergenic potency. Compared with the pollen extract, rArt v4.01 was superior in terms of reducing the number of white blood cells (WBCs), total nucleated cells (TNCs), and monocytes (MNs) in BALF and the degree of lung inflammation (1.77±0.99 vs. 2.31±0.80, P > 0.05). Compared with the model group, only rArt v4.01 reduced serum IgE level (1.19±0.25 vs. 1.61±0.17 μg/ml, P = 0.062), as well as the levels of Th2 type-related cytokines (interleukin-4 (IL-4) (107.18±16.17 vs. 132.47±20.85 pg/ml, P < 0.05) and IL-2 (19.52±1.19 vs. 24.02±2.14 pg/ml, P < 0.05)). The study suggested that rArt v4.01 was superior to pollen extract in reducing the number of inflammatory cells in BALF, pneumonitis, levels of pro-inflammatory cytokines, and serum IgE level. These findings confirmed that Art v4.01 could be a potential candidate protein for allergen-specific immunotherapy.

Association between lung opacities and visceral fat in COVID-19 patients.

To assess the relationship between the amount of the epigastric visceral fat area and the severity of pneumonia in the course of COVID-19 using chest computed tomography (CT) examinations. 177 patients (54 female), with COVID-19 infection were included. A routine chest CT was performed to assess the severity of pneumonia. The affected lung tissue as well as semi-quantitative scales such as the Chest CT Score and Total Opacity Score were calculated using SyngoVia VB30A CT Pneumonia Analysis software. The epigastric region area of visceral fat (L1) was also determined. The mean value of the visceral adipose tissue area was 196.23 ± 101.36 cm2. The area of adipose tissue significantly correlated with the percentage of the affected lung tissue (r = 0.1476; p = 0.050), the Chest CT Score (r = 0.2086; p = 0.005), and the Total Opacity Score (r = 0.1744; p = 0.200). The mean area of adipose tissue in the age group ≥ 65 years was 216.13 ± 105.19 cm2, while in the group < 65 years, it was 169.18 ± 89.69 cm2. This difference was statistically significant (p = 0.002). The study showed a relationship between the area of visceral adipose tissue and the degree of lung inflammation in COVID-19 disease in patients under 65 years of age.

Mechanism of total flavonoid extract from Dracocephalum moldavica on bleomycin-induced pulmonary fibrosis in mice based on pyroptosis pathway

This study investigated the mechanism of total flavonoid extract from Dracocephalum moldavica(TFDM) in mice with bleomycin(BLM)-induced pulmonary fibrosis(PF) and explored its mechanism against the pyroptosis pathway. A mouse model of PF was established by intratracheal infusion of bleomycin(4 mg·kg~(-1)), and the normal group was treated with the same dose of saline under the same conditions. After the second day of modeling, the distilled water was given to the normal and model groups by gavage, and the corresponding drug were given to the TFDM and the dexamethasone groups for 28 consecutive days. After 28 days, lung tissues of mice with PF were taken to determine the content of hydroxyproline(HYP). The degree of lung inflammation and fibrosis was observed by hematoxylin-eosin(HE) and Masson stainings, and the content of interleukin-18(IL-18) and interleukin-1β(IL-1β) in the serum of mice with PF were measured by enzyme-linked immunosorbent assay(ELISA). Western blot was used to determine the expression levels of proteins in the lung tissues of mice with PF. HE staining showed that the BLM group had abnormal lung tissue structures and showed more inflammatory cell infiltration. Masson staining showed plenty of collagenous fibrotic tissues that were stained blue in the lung tissues. As compared with the normal group, the content of HYP and levels of IL-18 and IL-1β in the serum of rats in the BLM group were up-regulated(P&lt;0.01). The protein expressions of type Ⅰ collagen(Col-1), fibronectin 1(FN1), α-smooth muscle actin(α-SMA), cysteinyl aspartate specific proteinase-1(caspase-1), gasdermin D(GSDMD), NOD-like receptor thermal protein domain associated protein 3(NLRP3), p62, and apoptosis-associated speck-like protein containing a CARD(ASC) in the lung tissues of mice with PF in the BLM group were increased(P&lt;0.01), whereas the protein expressions of autophagy-related 5(ATG5) and Beclin1 were decreased(P&lt;0.01). Compared with the BLM group, the TFDM groups and dexamethasone group showed normal lung tissue structures and reduced inflammatory cell infiltration. Less collagenous fibrous tissues in blue color were seen and the fibrosis in the lung tissue was alleviated in the TFDM groups and dexamethasone group, with the down-regulation of the content of HYP and the levels of IL-18 and IL-1β(P&lt;0.05, P&lt;0.01). In the TFDM groups and dexamethasone group, the protein expression levels of Col-1, FN1, α-SMA, caspase-1, GSDMD, NLRP3, p62, and ASC were decreased(P&lt;0.01), and the protein expressions of ATG5 and Beclin1 were increased(P&lt;0.01) in the lung tissues of mice with PF. From the above results, it is known that TFDM down-regulates the levels of inflammatory factors and related proteins, and effectively mitigates the process of BLM-induced PF by regulating the pyroptosis pathways and potentially affecting the autophagy.

Targeted nanotherapy with everolimus reduces inflammation and fibrosis in scleroderma-related interstitial lung disease developed by PSGL-1 deficient mice.

Interstitial lung disease (ILD) is the main cause of mortality in systemic sclerosis (SSc), and current therapies available are of low efficacy or high toxicity. Thus, the identification of innovative less toxic and high efficacy therapeutic approaches to ILD treatment is an urgent need. The interaction of P-selectin glycoprotein ligand-1 (PSGL-1) with P-selectin initiates leukocyte extravasation and deletion of the corresponding gene (Selplg) induces a SSc-like syndrome with high incidence of ILD in aged mice. Aged PSGL-1 KO (Selplg-/- ) mice were used to assess the therapeutic effects of nanotherapy with everolimus, included in liposomes decorated with high MW hyaluronic acid (LipHA+Ev) and administered intratracheally to specifically target CD44-expressing lung cells. PSGL-1 KO mice had increased numbers of CD45+ and CD45- cells, including alveolar and interstitial macrophages, eosinophils, granulocytes and NK cells, and myofibroblasts in bronchoalveolar lavage (BAL). CD45+ and CD45- cells expressing pro-inflammatory and pro-fibrotic cytokines were also increased. Lungs from PSGL-1 KO mice showed increased immune cell infiltration and apoptosis and exacerbated interstitial and peribronchial fibrosis. Targeted nanotherapy with LipHA+Ev decreased the myofibroblasts in BAL, cells producing proinflammatory and profibrotic cytokines, and the degree of lung inflammation at histology. LipHA+Ev treatment also decreased the severity of peribronchial and interstitial lung fibrosis, from moderate to mild levels. In PSGL-1 KO mice, targeted nanotherapy with LipHA+Ev was an effective treatment for SSc-ILD, reducing the number of inflammatory and fibrotic cells in BAL and reducing inflammation and fibrosis in lungs.

COVID-19-induced endotheliitis: emerging evidence and possible therapeutic strategies.

The coronavirus disease 2019 (COVID‐19) pandemic, a viral illness caused by the severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2), 1 has produced at the time of this writing nearly 33 million cases of infection, with over a million deaths in 235 countries, 2 causing an unprecedented burden on healthcare systems and a severe global socioeconomic crisis. As the pandemic spreads, knowledge on the disease course, as well as potential risk factors and predictors of severity is increasing daily, and initial data from randomised controlled studies have allowed care providers to refine therapeutic strategies. Nonetheless, mortality is markedly elevated among those presenting with severe disease, long‐term sequelae among survivors are unknown, and vaccine‐based therapies currently remain at early stages of development. Most reported cases are asymptomatic or present with mild symptoms; however, 7–26% of hospitalised patients experience severe disease, often requiring admission to intensive care units (ICUs), with progressive multiple organ dysfunction and high mortality. 3 , 4 , 5 Such differences in clinical outcomes have led physicians to initiate diverse pharmacological therapies at various stages of the disease, generating challenges as to the most appropriate therapeutic choice for COVID‐19. In this context, the use of dexamethasone has significantly reduced mortality rates in critically ill patients requiring supplemental oxygen or mechanical ventilation, 6 and remdesivir has demonstrated clinical benefit in hospitalised patients, but with unknown survival benefit to date 7 ; additional effective treatment options are therefore urgently needed. In an initial attempt to provide a uniform and widely reproducible methodology to guide systematic treatment strategies, a three‐stage classification of COVID‐19 has been proposed. 8 The Stage I or ‘early infection’ occurs at the initial establishment of disease with high viral replication, and commonly presents with a range of complaints that can include mild and often non‐specific influenza‐like signs and symptoms. Stage II is the ‘pulmonary phase’, with preferential viral‐mediated injury of the lung parenchyma and this is characterised by shortness of breath, hypoxia and pulmonary infiltrates with some degree of lung inflammation. Stage III is characterised by an exaggerated host immune‐inflammatory response to the virus, leading to acute respiratory distress syndrome (ARDS) and multi‐organ failure (MOF).

α1-Antitrypsin Polymerizes in Alveolar Macrophages of Smokers With and Without α1-Antitrypsin Deficiency

The deficiency of α1-antitrypsin (AAT) is secondary to misfolding and polymerization of the abnormal Z-AAT in liver cells and is associated with lung emphysema. Alveolar macrophages (AMs) produce AAT; however, it is not known whether Z-AAT can polymerize in AMs, further decreasing lung AAT and promoting lung inflammation. Our intention was to investigate whether AAT polymerizes in human AMs and to study the possible relation between polymerization and degree of lung inflammation. Immunohistochemical analysis with 2C1 monoclonal antibody specific for polymerized AAT was performed in sections of the following: nine lungs from individuals with AAT deficiency (AATD) and severe COPD; 35 smokers with normal AAT levels, of whom 24 had severe COPD and 11 did not have COPD; and 13 nonsmokers. AMs positive for AAT polymers were counted and expressed as the percentage of total AMs in the lungs. AAT polymerization was detected in 27%(4%-67%) of AMs from individuals with AATD but also in AMs from smokers with normal AAT with (24%[0%-70%]) and without (24%[0%-60%]) COPD, but not in AMs from nonsmokers (0%[0%-1.5%]) (P< .0001). Thepercentage of AMs with polymerized AAT correlated with pack-years smoked (r= 0.53, P= .0001), FEV1/FVC (r=-0.41, P= .005), small airways disease (r= 0.44, P= .004), and number of CD8+ Tcells and neutrophils in alveolar walls (r= 0.51, P= .002; r= 0.31, P=.05, respectively). Polymerization of AAT in alveolar macrophages occurs in the lungs of individuals with AATD but also in smokers with normal AAT levels with or without COPD. Our findings highlight the similarities in the pathophysiology of COPD in individuals with and without AATD, adding a potentially important step to the mechanism of COPD.

Soluble vimentin binds to P‐selectin and attenuates leukocytic infiltration into the lungs in murine endotoxin induced acute lung injury

BackgroundAcute lung injury (ALI) is a devastating condition that culminates as inflammation of the lungs mediated by leukocytic infiltration. In animal models, platelets and platelet P‐selectin are well described mediators of ALI and other forms of inflammation through enhancing capture and transmigration of neutrophils across vascular endothelium. Vimentin is an intermediate filament protein mainly thought to be involved in maintaining the cytoskeleton. Recently, there has been increasing evidence of vimentin's role during inflammation, although its precise role is unclear. We had recently observed that recombinant soluble vimentin (sVim) blocks neutrophil adhesion to platelets, endothelial cells, and P‐selectin monolayers; whether these observations translate into attenuation of ALI is unknown. Therefore, we hypothesize that soluble vimentin sVim blocks P‐selectin‐PSGL‐1 interactions and will decrease leukocytic infiltration into the lungs of endotoxin‐exposed mice.MethodsAll experiments were approved by the Institutional Animal Care and Use Committee at Baylor College of Medicine and the Michael E. DeBakey Veterans Affairs Medical Center. Recombinant sVim was expressed in E. coli and His‐purified using affinity chromatography. Binding kinetics of sVim to P‐selectin was determined using both enzyme‐linked immunosorbent assay (ELISA) and surface plasmon resonance (SPR). ELISA was performed by detecting sVim binding to immobilized P‐selectin/Fc or PSGL‐1/Fc protein. In SPR (BIACore), sVim was perfused over immobilized P‐selectin/Fc or IgG protein to determine the equilibrium dissociation constant KD. To determine whether sVim inhibits leukocytic infiltration into lungs after endotoxin exposure, C57BL/6 mice were treated with intraperitoneal injections of sVim (3 mg/kg) or vehicle control followed by endotoxin (O111:B4; 15 mg/kg) 1 hour later and then euthanized at 96 hours. Mice were evaluated by blinded investigators for both physical activity and degree of lung inflammation. Activity was determined using the mouse clinical assessment score for sepsis (M‐CASS) and lung inflammation was determined by alveolar septal thickening and leukocytic infiltration on hematoxylin and eosin stained sections.ResultssVim preferentially binds to P‐selectin/Fc and but not PSGL‐1/Fc in ELISA. Using SPR, sVim binds to P‐selectin/Fc with a KD of 125 ± 1.2 nM and not to IgG control. Endotoxin‐exposed mice treated with sVim were more active as determined by the M‐CASS (1.9 ± 0.2 vs 2.5 ± 0.2; 4‐point scale where lower is better; n=10/grp, p&lt;0.05). Mice receiving sVim also had less alveolar septal thickening and leukocytic infiltration into the lungs after exposure to endotoxin.ConclusionSoluble vimentin binds to P‐selectin and not P‐selectin glycoprotein ligand‐1 and decreases leukocytic infiltration into the lungs of endotoxin‐exposed mice. Further studies need to take place to determine whether vimentin also improves gas exchange in the lungs. Finally, dose‐response studies need to be performed to determine the optimal dose and timing of sVim to improve outcomes in acute lung injury.Support or Funding InformationNIH/NHLBI HL‐116524, NIH/NIGMS GM‐112806

Evaluation of the Tobacco Heating System 2.2. Part 4: 90-day OECD 413 rat inhalation study with systems toxicology endpoints demonstrates reduced exposure effects compared with cigarette smoke

The objective of the study was to characterize the toxicity from sub-chronic inhalation of test atmospheres from the candidate modified risk tobacco product (MRTP), Tobacco Heating System version 2.2 (THS2.2), and to compare it with that of the 3R4F reference cigarette. A 90-day nose-only inhalation study on Sprague-Dawley rats was performed, combining classical and systems toxicology approaches. Reduction in respiratory minute volume, degree of lung inflammation, and histopathological findings in the respiratory tract organs were significantly less pronounced in THS2.2-exposed groups compared with 3R4F-exposed groups. Transcriptomics data obtained from nasal epithelium and lung parenchyma showed concentration-dependent differential gene expression following 3R4F exposure that was less pronounced in the THS2.2-exposed groups. Molecular network analysis showed that inflammatory processes were the most affected by 3R4F, while the extent of THS2.2 impact was much lower. Most other toxicological endpoints evaluated did not show exposure-related effects. Where findings were observed, the effects were similar in 3R4F- and THS2.2-exposed animals. In summary, toxicological changes observed in the respiratory tract organs of THS2.2 aerosol-exposed rats were much less pronounced than in 3R4F-exposed rats while other toxicological endpoints either showed no exposure-related effects or were comparable to what was observed in the 3R4F-exposed rats.

Effect and mechanism of inhibition of lipopolysaccharide-induced pulmonary fibrosis by butyric acid

To evaluate the inhibitory effect of butyric acid (BA) as a histone deacetylase (HDAC) inhibitor on lipopolysaccharide (LPS)-induced pulmonary fibrosis and its mechanism. Thirty C57/BL6 mice were randomly divided into three groups according to the random number method, namely control group (physiological saline was given intraperitoneally and by gavage), LPS challenge group (LPS-induced murine model of pulmonary fibrosis was reproduced with intraperitoneal injection of 10 mg/kg LPS), and BA preconditioning + LPS challenge group (10 mg/kg BA was given followed by intraperitoneal injection of 10 mg/kg LPS), with 10 mice in each group. Mice were sacrificed painlessly, and lung tissue samples were harvested at 2 weeks and 4 weeks respectively (five samples every group each time). HDAC activity was evaluated with fluorescence analysis kit. Protein expression of acetylated-histone H3 (Ace-H3), acetylated-histone H4 (Ace-H4) and thymocyte differentiation antigen 1 (Thy-1) were determined by Western Blot. The mRNA expression of Thy-1 was assessed by real-time reverse transcription- polymerase chain reaction (real-time RT-PCR). The degree of lung inflammation and fibrosis were microscopic detected after hematoxylin-eosin (HE) staining and Masson collagen staining. The deposition of lung collagen was detected by hydroxyproline content measurement kit. Compared to control group, the degree of lung inflammation and fibrosis was aggravated after LPS challenge, as manifested by increased hydroxyproline content (μg/mg, 2 weeks: 8.384±0.632 vs. 4.388±0.334, 4 weeks: 8.308±0.244 vs. 4.370±0.342, both P < 0.01), increased HDAC activity (μmol/L, 2 weeks: 7.243±0.384 vs. 3.628±0.641, 4 weeks: 6.479±0.202 vs. 3.238±0.524, both P < 0.01), increased deacetylation degree of histone H3 and H4 [relative expression of Ace-H3 (gray value): 0.516±0.115 vs. 1.005±0.359 at 2 weeks, 0.633±0.143 vs. 1.092±0.193 at 4 weeks, both P < 0.05; relative expression of Ace-H4 (gray value): 0.402±0.164 vs. 0.759±0.187 at 2 weeks, P > 0.05; 0.426±0.098 vs. 0.858±0.177 at 4 weeks, P < 0.01], and lowered Thy-1 mRNA and protein expression [Thy-1 mRNA (2(-ΔΔCt)): 0.606±0.066 vs. 1.005±0.109 at 2 weeks, P < 0.01; 0.824±0.101 vs. 1.210±0.400 at 4 weeks, P > 0.05; relative expression of Thy-1 protein (gray value): 0.725±0.284 vs. 1.249±0.297 at 2 weeks, 0.589±0.139 vs. 1.372±0.343 at 4 weeks, both P < 0.05]. Compared with LPS group, BA precondition could inhibit above processes, as manifested by decreased hydroxyproline content (μg/mg: 5.943±0.726 vs. 8.384±0.632 at 2 weeks, 4.938±0.209 vs. 8.308±0.244 at 4 weeks, both P < 0.01), decreased HDAC activity (μmol/L: 4.386±0.117 vs. 7.243±0.384 at 2 weeks, 4.863±0.096 vs. 6.479±0.202 at 4 weeks, both P < 0.01), increased Thy-1 mRNA expression at 2 weeks (2(-ΔΔCt): 0.884±0.216 vs. 0.606±0.066, P < 0.05), increased acetylation degree of histone H4 and Thy-1 protein expression at 4 weeks [relative expression of Ace-H4 (gray value): 0.715±0.145 vs. 0.426±0.098, P < 0.05; relative protein expression of Thy-1 (gray value): 0.939±0.098 vs. 0.589±0.139, P < 0.01]. LPS-induced pulmonary fibrosis was related with activation of HDAC, deacetylation of histone H3 and H4 and Thy-1 gene silencing. HDAC inhibitor BA could inhibit LPS-induced pulmonary fibrosis and Thy-1 gene silencing through inhibiting activation of HDAC and deacetylation of histone H4.

Dexpanthenol therapy reduces lung damage in a hyperoxic lung injury in neonatal rats

Objective: Dexpanthenol (Dxp) plays a major role in cellular defense and in repair systems against oxidative stress and inflammatory response and it has not yet been evaluated in treatment of bronchopulmonary dysplasia (BPD). We tested the hypothesis that proposes whether Dxp decreases the severity of lung injury in an animal model of BPD.Methods: Forty rat pups were divided into four groups: control, control + Dxp, hyperoxia and hyperoxia + Dxp. All animals were processed for lung histology and tissue analysis. The degree of lung inflammation, oxidative and antioxidant capacity was assessed from lung homogenates.Results: Lung injury score and alveol diameter increased in the hyperoxia group (p < 0.001). Median level of malondialdehyde, total oxidant status and oxidative stress indexes was significantly higher in the hyperoxia group compared to the other groups. The median superoxide dismutase activity in the hyperoxia group was notably less than those of control + Dxp and hyperoxia + Dxp groups (p < 0.01). Similarly, lung catalase, glutathione (GSH) peroxidase and reduced GSH activities in the hyperoxia group were significantly lower than other groups. Furthermore, the hyperoxia + Dxp group had lower tumor necrosis factor-α and interleukin-1β median levels compared to the hyperoxia group (p = 0.007).Conclusion: Dxp treatment results in less emphysematous change as well as decrease in inflammation and oxidative stress markers in an animal model of BPD.

Management of the idiopathic interstitial pneumonias

The idiopathic interstitial pneumonias are characterised by varying degrees of lung inflammation

Colchicine Protects against Hyperoxic Lung Injury in Neonatal Rats

Background: Bronchopulmonary dysplasia (BPD) is characterized by inflammation, fibrosis and mucosal necrosis, which leads to emphysematous coalescence of alveoli. Objective: We tested whether prophylaxis with colchicine , an anti-inflammatory, antioxidant and antifibrotic drug, would decrease the severity of lung injury in an animal model of BPD. Methods: Twenty-five rat pups were divided into three groups: control (n = 8), hyperoxia (n = 7), and hyperoxia + colchicine (n = 10). The hyperoxia groups were exposed to >95% oxygen from day 1 to 10 of life. On day 10, the animals were sacrificed and the lungs were processed for histology and biochemical analysis. Lung morphology was assessed by the mean linear intercept (MLI), a measure of alveolar size. The degree of lung inflammation and antioxidant capacity were assessed by quantifying lung homogenate tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) levels. Results: Colchicine significantly decreased lung damage as determined by the MLI in the hyperoxia groups (p < 0.01). The median level of lung MDA was significantly higher in the hyperoxia group compared with the control group (p < 0.05) and the colchicine-treated group (p < 0.05). Lung homogenate SOD and GSH-Px activities in the colchicine-treated group were significantly higher than in the hyperoxia group (p < 0.05). Furthermore, colchicine-treated pups had lower lung homogenate TNF-α and IL-1β levels compared with the hyperoxia group (p < 0.05). Conclusions: Colchicine has favorable effects on alveolarization as well as inflammation and oxidative stress markers in an animal model of BPD.

Effect of PD98059, a Selective MAPK3/MAPK1 Inhibitor, on Acute Lung Injury in Mice

The aim of the present study is to evaluate the contribution of mitogen-activated protein kinase 1-3 MAPK3/MAPK1) in a model of acute lung inflammation in mice. Injection of carrageenan into the pleural cavity of mice elicited an acute inflammatory response characterized by: accumulation of fluid containing a large number of neutrophils (PMNs) in the pleural cavity, infiltration of PMNs in lung tissues and subsequent adhesion molecule expression (I-CAM and P-selectin), lipid peroxidation, and increased production of tumour necrosis factor-alpha, (TNF-alpha) and interleukin-1beta (IL-1beta). Furthermore, carrageenan induced lung apoptosis (Bax and Bcl-2 expression) as well as nitrotyrosine formation, NF-kB activation, and pJNK expression, as determined by immunohistochemical analysis of lung tissues and the degree of lung inflammation and tissue injury (histological score). Administration of PD98059, an inhibitor of MAPK3/MAPK1 (10 mg/kg) 1 h after carrageenan caused a reduction in all the parameters of inflammation measured. Thus, based on these findings we propose that inhibitors of the MAPK3/MAPK1 signaling pathways, such as PD98059, may be useful in the treatment of various inflammatory diseases.

Desensitization of ovalbumin-sensitized mice by repeated co-administrations of di-(2-ethylhexyl) phthalate and ovalbumin

BackgroundThe plasticizer di-(2-ethylhexyl) phthalate (DEHP) has been shown to stimulate a non-allergy related immune response with increased levels of IgG1 and IgG2a, but not IgE, after co-administration with the model allergen ovalbumin (OVA) in mice. In mice, decreased IgG1 and increased IgG2a have been associated with the development of mucosal tolerance towards inhaled allergens. As DEHP selectively promote formations of IgG1 and IgG2a without stimulating the IgE response, it was hypothesized that DEHP may suppress an established IgE mediated allergic response. Mice pre-sensitised to OVA were repeatedly co-exposed to DEHP and OVA and the effects were evaluated on the levels of OVA-specific antibodies, ex vivo cytokine levels and the degree of lung inflammation after challenge with an OVA aerosol.FindingsCompared to the OVA-sensitised control mice, multiple co-exposures to DEHP+OVA reduced the IgG1 level and reduced the IgE/IgG2a ratio. This suggests that DEHP may attenuate allergic sensitisation, as the IgE/IgG2a ratio has been shown to correlate with the degree of anaphylaxis. Nevertheless, no effect of DEHP exposures was seen on inflammatory cells in bronchoalveolar lavage fluid and on cytokine levels in spleen cell culture.ConclusionData from humane and murine studies suggest that DEHP may attenuate the allergic response. More studies are necessary in order to assess the size of this effect and to rule out the underlying mechanism.

Identification of a Common Gene Expression Response in Different Lung Inflammatory Diseases in Rodents and Macaques

To identify gene expression responses common to multiple pulmonary diseases we collected microarray data for acute lung inflammation models from 12 studies and used these in a meta-analysis. The data used include exposures to air pollutants; bacterial, viral, and parasitic infections; and allergic asthma models. Hierarchical clustering revealed a cluster of 383 up-regulated genes with a common response. This cluster contained five subsets, each characterized by more specific functions such as inflammatory response, interferon-induced genes, immune signaling, or cell proliferation. Of these subsets, the inflammatory response was common to all models, interferon-induced responses were more pronounced in bacterial and viral models, and a cell division response was more prominent in parasitic and allergic models. A common cluster containing 157 moderately down-regulated genes was associated with the effects of tissue damage. Responses to influenza in macaques were weaker than in mice, reflecting differences in the degree of lung inflammation and/or virus replication. The existence of a common cluster shows that in vivo lung inflammation in response to various pathogens or exposures proceeds through shared molecular mechanisms.

Inhaled Asbestos Exacerbates Atherosclerosis in Apolipoprotein E–Deficient Mice via CD4 + T Cells

BackgroundAssociations between air pollution and morbidity/mortality from cardiovascular disease are recognized in epidemiologic and clinical studies, but the mechanisms by which inhaled fibers or particles mediate the exacerbation of atherosclerosis are unclear.Objective and methodsTo determine whether lung inflammation after inhalation of a well-characterized pathogenic particulate, chrysotile asbestos, is directly linked to exacerbation of atherosclerosis and the mechanisms involved, we exposed apolipoprotein E–deficient (ApoE−/−) mice and ApoE−/− mice crossed with CD4−/− mice to ambient air, NIEHS (National Institute of Environmental Health Sciences) reference sample of chrysotile asbestos, or fine titanium dioxide (TiO2), a nonpathogenic control particle, for 3, 9, or 30 days.ResultsApoE−/− mice exposed to inhaled asbestos fibers had approximately 3-fold larger atherosclerotic lesions than did TiO2-exposed ApoE−/− mice or asbestos-exposed ApoE−/−/CD4−/− double-knockout (DKO) mice. Lung inflammation and the magnitude of lung fibrosis assessed histologically were similar in asbestos-exposed ApoE−/− and DKO mice. Monocyte chemoattractant protein-1 (MCP-1) levels were increased in bronchoalveolar lavage fluid and plasma, and plasma concentrations correlated with lesion size (p < 0.04) in asbestos-exposed ApoE−/− mice. At 9 days, activator protein-1 (AP-1) and nuclear factor-κB (NF-κB), transcription factors linked to inflammation and found in the promoter region of the MCP-1 gene, were increased in aortas of asbestos-exposed ApoE−/− but not DKO mice.ConclusionOur findings show that the degree of lung inflammation and fibrosis does not correlate directly with cardiovascular effects of inhaled asbestos fibers and support a critical role of CD4+ T cells in linking fiber-induced pulmonary signaling to consequent activation of AP-1– and NF-κB–regulated genes in atherogenesis.

Toxicity of Fiber- and Penton Base–modified Adenovirus Type 5 Vectors on Lung Development in Newborn Rats

Transient overexpression of genes involved in lung regulation might prevent alveolar developmental disorders (ADDs) in premature neonates. However, adenovirus 5 (Ad5) vectors per se, and not isolated capsid proteins, induce ADDs after tracheal administration to newborn rats. To test the hypothesis that Ad5 capsid components are mainly responsible for ADDs, we evaluated newborn rats' lung development by morphometry after tracheal administration of a panel of Ad5 vectors with mutations in the fiber or penton base. Three distinct patterns of lung response were observed on postnatal day (PD) 21: (i) emphysematous-like lesions, common to Ad5 overexposing RGD motifs; (ii) altered septation, representative of the wild-type capsid Ad5 lesion; (iii) absence of lung toxicity, shown by Ad5 vectors with fibers shortened to seven repeats. None of these patterns correlated with the degree of lung inflammation or gene transduction. In contrast, a more impaired elastogenesis associated with emphysema was preceded by a significantly increased level of activated caspase 3 on PD11. Moreover, the altered septation was associated with a persistent and significant increase in terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL)-positive alveolar septal cells on PD21. Our results underline the deleterious effects of Ad-induced apoptosis, which is not only responsible for limited transgene expression but also involved in lung development disorders.

Azithromycin Protects Against Hyperoxic Lung Injury in Neonatal Rats

Bronchopulmonary dysplasia (BPD) is a pulmonary disorder that causes significant morbidity and mortality in premature infants. BPD is pathologically characterized by inflammation, fibrosis, and mucosal necrosis, which leads to emphysematous...

Increased susceptibility of MER5 (peroxiredoxin III) knockout mice to LPS-induced oxidative stress

MER5 (also called peroxiredoxin III, PrxIII) is a member of peroxiredoxin family that has antioxidant activity. The present study was performed to investigate its in vivo function using MER5 knockout mice. MER5 knockout mice were born in normal frequency and could grow to maturity, but we found that intracellular ROS levels are significantly higher in the macrophages of the knockout mice. We examined roles of MER5 function for the oxidative stress responses by intratracheal inoculation of lipopolysaccharide (LPS) to the mice. Lung inflammation such as inflammatory cell infiltration and airway wall thickening was more severely detected in the knockout mice. At the same time, oxidative damage on DNA and proteins was more strongly detected in lung tissues of the knockout mice, including 8-hydroxy-2′-deoxyguanosine (8-OHdG) formation and protein carbonylation. The degrees of lung inflammation and oxidative damage were positively related with LPS doses. Our results indicate that MER5 knockout mice accumulated higher intracellular ROS levels, which cause LPS-induced lung injury more severely, and thus, suggested that MER5 acts as an important scavenger of reactive oxygen species (ROS) under oxidative stress.

82 Increasing levels of precipitating antibodies to Achromobacter xylosoxidans and Burkholderia multivorans reflect more aggressive pulmonary disease in chronically infected Cystic Fibrosis patients

Introduction; Absolute level and rapidly increasing levels of precipitating antibodies to Pseudomonas aeruginosa (PA) in chronic pulmonary infection in cystic fibrosis (CF) are correlated with degree of lung inflammation, tissue damage and poor prognosis. Precipitating antibodies to other Gram-negative bacteria may exhibit similar properties. Aims; To assess the correlation between levels of precipitins to Achromobacter xylosoxidans (AX), and Burkholderia multivorans iBM) and lung function in chronically infected CF patients. Methods: All patients with a diagnosis of chronic infection with either AX or BM as per 2005 were included. The correlation between level of precipitating antibodies and FEV1% predicted was assessed. Results; 14 patients with chronic AX had median (range) FEV1% predicted of 66% (23 to 111%) and precipitin levels of 25 (3 to 40) showing statistically significant, but weak, negative correlation (r2 0.24, p < 0.05). Correspondingly, in 12 patients with chronic BM a statistically significant negative correlation (r2 0.65, p < 0.05) was shown between lung function: 63% (40 to 110%) and precipitin levels: 17 (8 to 25). Conclusion: Chronic infection with AX or BM, like PA, induces increasing levels of precipitins as markers of enhanced tissue damage as reflected in declining lung function. Precipitins to other Gram-negative bacteria than PA may function as markers of infection severity, treatment success or failure. S19