Pulmonary Inflammation In Mice Research Articles

Activation of TREM-1 induces endoplasmic reticulum stress through IRE-1α/XBP-1s pathway in murine macrophages

Increasing evidence suggests that endoplasmic reticulum (ER) stress activates several pro-inflammatory signaling pathways in many diseases, including acute lung injury (ALI). We have reported that blocking triggering receptor expressed on myeloid cells 1 (TREM-1) protects against ALI by suppressing pulmonary inflammation in mice with ALI induced by lipopolysaccharides (LPS). However, the molecular mechanism underlying the TREM-1-induced pro-inflammatory microenvironment in macrophages remains unclearly. Herein, we aimed to determine whether TREM-1 regulates the inflammatory responses induced by LPS associated with ER stress activation. We found that the activation of TREM-1 by a monoclonal agonist antibody (anti-TREM-1) increased the mRNA and protein levels of IL-1β, TNF-α, and IL-6 in primary macrophages. Treatment of the anti-TREM-1 antibody increased the expression of ER stress markers (ATF6, PERK, IRE-1α, and XBP-1s) in primary macrophages. While pretreatment with 4-PBA, an inhibitor of ER stress, significantly inhibited the expression of ER stress markers and pro-inflammatory cytokines and reduced LDH release. Furthermore, inhibiting the activity of the IRE-1α/XBP-1s pathway by STF-083010 significantly mitigated the increased levels of IL-1β, TNF-α, and IL-6 in macrophages treated by the anti-TREM-1 antibody. XBP-1 silencing attenuated pro-inflammatory microenvironment evoked by activation of TREM-1. Besides, we found that blockade of TREM-1 with LR12 ameliorated ER stress induced by LPS in vitro and in vivo. In conclusion, we conclude that TREM-1 activation induces ER stress through the IRE-1α/XBP-1s pathway in macrophages, contributing to the pro-inflammatory microenvironment.

Vitamin B6 inhibits macrophage activation to prevent lipopolysaccharide-induced acute pneumonia in mice.

Macrophage activation participates in the pathogenesis of pulmonary inflammation. As a coenzyme, vitamin B6 (VitB6) is mainly involved in the metabolism of amino acids, nucleic acids, glycogen and lipids. We have previously reported that activation of AMP‐activated protein kinase (AMPK) produces anti‐inflammatory effects both in vitro and in vivo. Whether VitB6 via AMPK activation prevents pulmonary inflammation remains unknown. The model of acute pneumonia was induced by injecting mice with lipopolysaccharide (LPS). The inflammation was determined by measuring the levels of interleukin‐1 beta (IL‐1β), IL‐6 and tumour necrosis factor alpha (TNF‐α) using real time PCR, ELISA and immunohistochemistry. Exposure of cultured primary macrophages to VitB6 increased AMP‐activated protein kinase (AMPK) Thr172 phosphorylation in a time/dose‐dependent manner, which was inhibited by compound C. VitB6 downregulated the inflammatory gene expressions including IL‐1β, IL‐6 and TNF‐α in macrophages challenged with LPS. These effects of VitB6 were mirrored by AMPK activator 5‐aminoimidazole‐4‐carboxamide ribonucleoside (AICAR). However, VitB6 was unable to inhibit LPS‐induced macrophage activation if AMPK was in deficient through siRNA‐mediated approaches. Further, the anti‐inflammatory effects produced by VitB6 or AICAR in LPS‐treated macrophages were abolished in DOK3 gene knockout (DOK3 −/−) macrophages, but were enhanced in macrophages if DOK3 was overexpressed. In vivo studies indicated that administration of VitB6 remarkably inhibited LPS‐induced both systemic inflammation and acute pneumonia in wild‐type mice, but not in DOK3 −/− mice. VitB6 prevents LPS‐induced acute pulmonary inflammation in mice via the inhibition of macrophage activation.

Lapiferin protects against H1N1 virus-induced pulmonary inflammation by negatively regulating NF-kB signaling.

H1N1 virus-induced excessive inflammatory response contributes to severe disease and high mortality rates. There is currently no effective strategy against virus infection in lung. The present study evaluated the protective roles of a natural compound, lapiferin, in H1N1 virus-induced pulmonary inflammation in mice and in cultured human bronchial epithelial cells. Initially, Balb/C mice were grouped as Control, H1N1 infection (intranasally infected with 500 plaque-forming units of H1N1 virus), lapiferin (10 mg/kg), and H1N1+lapiferin (n=10/group). Lung histology, expression of inflammatory factors, and survival rates were assessed after 14 days of exposure. Administration of lapiferin significantly alleviated the virus-induced inflammatory infiltrate in lung tissues. Major pro-inflammatory cytokines, such as interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α, were decreased at both mRNA and protein levels by lapiferin administration in the lung homogenate. Lapiferin also reduced inflammatory cell numbers in bronchoalveolar fluid. Mechanistically, lapiferin suppressed the transcriptional activity and protein expression of NF-κB p65, causing inhibition on NF-κB signaling. Pre-incubation of human bronchial epithelial cells with an NF-κB signaling specific activator, ceruletide, significantly blunted lapiferin-mediated inhibition of pro-inflammatory cytokines secretion in an air-liquid-interface cell culture experiment. Activation of NF-κB signaling also blunted lapiferin-ameliorated inflammatory infiltrate in lungs. These results suggested that lapiferin was a potent natural compound that served as a therapeutic agent for virus infection in the lung.

The role of miR-155 in cigarette smoke-induced pulmonary inflammation and COPD.

Chronic obstructive pulmonary disease (COPD) is a highly prevalent respiratory disease characterized by airflow limitation and chronic inflammation. MiR-155 is described as an ancient regulator of the immune system. Our objective was to establish a role for miR-155 in cigarette smoke (CS)-induced inflammation and COPD. We demonstrate increased miR-155 expression by RT-qPCR in lung tissue of smokers without airflow limitation and patients with COPD compared to never smokers and in lung tissue and alveolar macrophages of CS-exposed mice compared to air-exposed mice. In addition, we exposed wild type and miR-155 deficient mice to CS and show an attenuated inflammatory profile in the latter. Alveolar macrophages were sorted by FACS from the different experimental groups and their gene expression profile was analyzed by RNA sequencing. This analysis revealed increased expression of miR-155 targets and an attenuation of the CS-induced increase in inflammation-related genes in miR-155 deficient mice. Moreover, intranasal instillation of a specific miR-155 inhibitor attenuated the CS-induced pulmonary inflammation in mice. Finally, elastase-induced emphysema and lung functional changes were significantly attenuated in miR-155 deficient mice. In conclusion, we highlight a role for miR-155 in CS-induced inflammation and the pathogenesis of COPD, implicating miR-155 as a new therapeutic target in COPD.

Ophiopogon japonicus inhibits radiation-induced pulmonary inflammation in mice.

Radiation-induced lung injury, including the acute pulmonary inflammation and chronic pulmonary fibrosis remains the major complication of thoracic radiotherapy. In this study, we assessed the effects of Ophiopogon japonicus (O. japonicas) in inhibiting the radiation-induced pulmonary inflammation through an acute lung injury mouse model using C57BL/6 mice that received 18 Gy irradiation to the thoracic region. Starting at 4 days before radiation, mice were treated with O. japonicus or dexamethasone combined with cephalexin or vehicle daily for 14 days. Exposure to radiation resulted in pulmonary inflammation in mice, but treatment with O. japonicus or dexamethasone-cephalexin could both significantly reduce radiation-induced pulmonary inflammation through inhibition of IL-6, TNF-α, TGF-β1, hydroxyproline, MDA, MMP-2 and TIMP-2 in plasma or lung tissue. In addition, through analyzing tissue damage, cytokines and inflammation-related protein at 12 weeks after irradiation, we found that the protective effect of O. japonicus was more enduring than dexamethasone-cephalexin. As radiation-induced lung injury is a major obstacle in thoracic radiotherapies and seriously affect the quality of patients' life. Application of O. japonicus may be a novel strategy to manage radiation-induced pulmonary inflammation.

Inhibitory effects of compounds isolated from Dioscorea batatas Decne peel on particulate matter-induced pulmonary injury in mice

ABSTRACTParticulate matter 2.5 (PM2.5), with an aerodynamic diameter of ≤2.5 μm, is the primary air pollutant that plays a key role associated with lung injury produced by loss of vascular barrier integrity. Dioscorea batatas Decne (Chinese yam), a perennial plant belonging to Dioscoreaceae family, is widely cultivated in tropical and subtropical regions across Asia. Both aerial parts and root of D. batatas are consumed for nutritional and medicinal purposes. The aim of this study was to (1) identify the bioactive compounds present in D. batatas peel which may be responsible for inhibition of PM2.5-induced pulmonary inflammation in mice and (2) examine in vitro mechanisms underlying the observed effects of these compounds on mouse lung microvascular endothelial cells. The measured parameters include permeability, leukocyte migration, proinflammatory protein activation, reactive oxygen species (ROS) generation, and histology. Two phenanthrene compounds, 2,7-dihydroxy-4,6-dimethoxyphenanthrene (1) and 6,7-dihydroxy-2,4-dimethoxyphenanthrene (2) were isolated from D. batatas peels. Both these phenanthrene compounds exhibited significant scavenging activity against PM2.5-induced ROS and inhibited ROS-induced activation of p38 mitogen-activated protein kinase. In addition, enhancement of Akt pathway, involved in the maintenance of endothelial integrity, was noted. These phenanthrene compounds also reduced vascular protein leakage, leukocyte infiltration, and proinflammatory cytokine release in the bronchoalveolar lavage fluid obtained from PM2.5-induced lung tissues. Evidence thus indicates that phenanthrene compounds derived from D. batatas may exhibit protective effects against PM2.5-induced inflammatory lung injury and vascular hyperpermeability in mice.

HO-1 mediates the anti-inflammatory actions of Sulforaphane in monocytes stimulated with a mycoplasmal lipopeptide

Exposure to Mycoplasma pneumoniae leads to lung inflammation through a host defense pathway. Increasing evidence has indicated that the mycoplasma-derived membrane lipoprotein, or its analogue macrophage-activating lipopeptide-2 (MALP-2), excretes LPS as an immune system-stimulating substance and plays a crucial role in pathological injury during M. pneumoniae infection. It has been established that Sulforaphane confers anti-inflammatory properties. However, the underlying mechanism responsible for the inhibitory actions of Sulforaphane in the context of mycoplasmal pneumoniae are poorly understood. Here, we report that Sulforaphane is an inducer of heme oxygenase (HO)-1, a cytoprotective enzyme that catalyzes the degradation of heme through signaling pathways in human monocytes. Sulforaphane stimulated NF-E2-related factor 2 (Nrf2) translocation from the cytosol to the nucleus, and small interfering RNA-mediated knock-down of Nrf2 significantly inhibited Sulforaphane-induced HO-1 expression. Additionally, PI3K/Akt and ROS were also involved in Sulforaphane-induced Nrf2 activation and HO-1 expression, as revealed by the pharmacological inhibitors LY294002 and NAC. Moreover, Sulforaphane treatment inhibited MALP-2-induced pro-inflammatory cytokine secretion and pulmonary inflammation in mice, as well as MALP-2-triggered NF-κB activation. Furthermore, SnPP, a selective inhibitor of HO-1, reversed the inhibitory actions of Sulforaphane, while a carbon monoxide-releasing molecule, CORM-2, caused a significant decrease in MALP-2-induced cytokine secretion. Collectively, these results suggest that Sulforaphane functions as a suppressor of the MALP-2-induced inflammatory response, not only by inhibiting the expression of cytokines and the induction of HO-1 but also by diminishing NF-κB activation in cultured monocytes and the lungs of mice.

Persistent elevation of blood pressure by ambient coarse particulate matter after recovery from pulmonary inflammation in mice.

Exposure to ambient particulate matter (PM) is associated with hypertension and cardiovascular diseases. Recently, we reported that exposure to fine and coarse PM caused pulmonary inflammation and pulmonary small arterial remodeling in mice, and osteopontin (OPN) level was elevated following PM exposure. However, in the present study, cotreatment with 5-methoxytryptophan for 4 weeks partially reduced coarse PM-induced pulmonary inflammation without reducing pulmonary OPN secretion or recovery from pulmonary arterial remodeling in mice. Persistent vascular dysfunction may lead to vascular remodeling. Therefore, we further compared the relationship between coarse PM-induced inflammation and vascular dysfunction by exposing mice to PM before and after cessation of PM exposure. Oropharyngeal aspiration of PM for 8 weeks induced pulmonary inflammation and pulmonary small artery remodeling in mice, as well as increased serum C-reactive protein and OPN concentrations and systolic blood pressure (SBP). After the cessation of PM exposure for another 8 weeks, lung inflammation had recovered and vascular remodeling had partially recovered. Elevation of OPN, metalloproteinases (MMPs), and cytokines in bronchioalveolar lavage were significantly reduced. However, PM-induced systemic responses did not recover after the cessation of PM exposure. Notably, not only serum OPN and SBP remained significantly elevated; also, serum endothelin-1, MMP-9, and keratinocyte-derived chemokine concentrations were significantly increased after cessation of PM exposure for another 8 weeks. These data suggested that systemic inflammation and systemic vascular dysfunction might be important in PM-induced elevation of SBP. Furthermore, SBP elevation was persistent after cessation of PM exposure for 8 weeks.

Small-Animal PET/CT Imaging of Local and Systemic Immune Response Using 64Cu-αCD11b.

Current noninvasive imaging methods for monitoring immune response were largely developed for interrogation of the local reaction. This study developed the radiotracer 64Cu-labeled anti-CD11b (64Cu-αCD11b) for longitudinal assessment of local and systemic immune response involving mobilization of CD11b+ myeloid cells by small-animal PET/CT. Methods: Acute or chronic inflammation in the ears of BALB/c mice was induced by 12-o-tetradecanoylphorbol-13-acetate. Acute lung inflammation was induced by intratracheal lipopolysaccharide inoculation. αCD11b was conjugated with p-SCN-Bn-DOTA followed by labeling with 64Cu. PET/CT and biodistribution were evaluated at different times after intravenous injection of 64Cu-αCD11b. Cell populations from bone marrow (BM) and spleen were analyzed by flow cytometry. Results:64Cu-αCD11b was primarily taken up by BM and spleen in control mice. In comparison, 64Cu-αCD11b uptake was significantly reduced in the BM and spleen of CD11b-knockout mice, indicating that 64Cu-αCD11b selectively homed to CD11b+ myeloid cells in vivo. In mice with ear inflammation, for the local inflammatory response, 64Cu-αCD11b PET/CT revealed significantly higher 64Cu-αCD11b uptake in the inflamed ears in the acute inflammation phase than the chronic phase, consistent with markedly increased infiltration of CD11b+ cells into the inflammatory lesions at the acute phase. Moreover, imaging of 64Cu-αCD11b also showed the difference in mouse systemic response for different inflammatory stages. Compared with uptake in control mice, BM 64Cu-αCD11b uptake in mice with ear inflammation was significantly lower in the acute phase and higher in the chronic phase, reflecting an initial mobilization of CD11b+ cells from the BM to the inflammatory foci followed by a compensatory regeneration of CD11b+ myeloid cells in the BM. Similarly, in mice with lung inflammation, 64Cu-αCD11b PET/CT readily detected acute lung inflammation and recruitment of CD11b+ myeloid cells from the BM. Immunohistochemistry staining and flow cytometry results confirmed the noninvasive imaging of PET/CT. Conclusion:64Cu-αCD11b PET/CT successfully tracked ear and pulmonary inflammation in mice and differentiated acute from chronic inflammation at the local and systemic levels. 64Cu-αCD11b PET/CT is a robust quantitative method for imaging of local and systemic immune responses.

Mechanical ventilation enhances extrapulmonary sepsis-induced lung injury: role of WISP1\u2013\u03b1v\u03b25 integrin pathway in TLR4-mediated inflammation and injury

BackgroundHigh tidal volume ventilation of healthy lungs or exacerbation of existing acute lung injury (ALI) by more moderate mechanical ventilation (MTV) produces ventilator-induced lung injury. It is less clear whether extrapulmonary sepsis sensitizes the lung to MTV.MethodsWe used a two-hit model of cecal ligation and puncture (CLP) followed 12 h later by MTV (10 ml/kg; 6 h) to determine whether otherwise noninjurious MTV enhances CLP-induced ALI by contrasting wildtype and TLR4−/− mice with respect to: alveolar-capillary permeability, histopathology and intrapulmonary levels of WNT-inducible secreted protein 1 (WISP1) and integrin β5; plasma levels of cytokines and chemokines (TNF-α, IL-6, MIP-2, MCP-1) and intrapulmonary neutrophil infiltration; and other inflammatory signaling via intrapulmonary activation of JNK, p38 and ERK. A separate cohort of mice was pretreated with intratracheal neutralizing antibodies to WISP1, integrin β5 or IgG as control and the presented phenotyping repeated in a two-hit model; there were 10 mice per group in these first three experiments. Also, isolated peritoneal macrophages (PM) from wildtype and TLR4−/−, MyD88−/− and TRIF−/− mice were used to identify a WISP1–TLR4–integrin β5 pathway; and the requisite role of integrin β5 in WISP1-induced cytokine and chemokine production in LPS-primed PM was examined by siRNA treatment.ResultsMTV, that in itself did not cause ALI, exacerbated increases in alveolar-capillary permeability, histopathologic scoring and indices of pulmonary inflammation in mice that previously underwent CLP; the effects of this two-hit model were abrogated in TLR4−/− mice. Attendant with these findings was a significant increase in intrapulmonary WISP1 and integrin β5 in the two-hit model. Anti-WISP1 or anti-integrin β5 antibodies partially inhibited the two-hit phenotype. In PM, activation of TLR4 led to an increase in integrin β5 expression that was MyD88 and NF-κB dependent. Recombinant WISP1 increased LPS-induced cytokine release in PM that was inhibited by silencing either TLR4 or integrin β5.ConclusionsThese data show for the first time that otherwise noninjurious mechanical ventilation can exacerbate ALI due to extrapulmonary sepsis underscoring a potential interactive contribution of common events (sepsis and mechanical ventilation) in critical care, and that a WISP1–TLR4–integrin β5 pathway contributes to this phenomenon.

Hyaluronan Reduces Cationic Liposome-Induced Toxicity and Enhances the Antitumor Effect of Targeted Gene Delivery in Mice.

Cationic nanocarriers are reported to induce cell necrosis, especially in the lungs upon systemic administration. The release of damage-associated molecular patterns, such as mitochondrial DNA from the injured cell may result in the inflammatory toxicity of the nanocarrier, which has largely limited its clinical application. Partial blocking of the surface charge of cationic nanocarriers might improve their safety. As hyaluronan (HA) is an anionic polysaccharide that is widely used for specific binding to CD44 to improve the cellular uptake efficiency in tumor-targeting therapy, in this study, we modified cationic liposomes (LP) with the negatively charged HA at a mass ratio of 10% to prepare targeted HA-modified cationic liposomes (HALP). Cationic liposomes modified with hyaluronan showed significantly less cytotoxicity due to the blockage of their surface charge than the unmodified liposomes. In addition, HA modification helped to reduce cell necrosis in lung tissue and reduced the amount of mitochondria subsequently released, which alleviated pulmonary inflammation in mice. HA-modified liposomes also improved the survival of mice injected with a fatal dose of HALP compared with mice injected with cationic LP. In addition, both serological biochemical analysis and histological examination proved that a liposome modified with HA is a safer carrier for systemic administration than an unmodified liposome. Furthermore, HALP/survivin exhibited an enhanced antitumor effect by inhibiting tumor growth and promoting tumor cell apoptosis compared with the unmodified LP group. In conclusion, compared to the properties of cationic liposomes, liposomes modified with 10% HA (HALP) might be gene vectors with lower toxicity and higher tumor targeting efficiency.

Blockade of Aquaporin 4 Inhibits Irradiation-Induced Pulmonary Inflammation and Modulates Macrophage Polarization in Mice.

To investigate the effects of aquaporin 4 (AQP4) inhibitor in irradiation-induced pulmonary inflammation in mice. A single dose of 75Gy was delivered to the left lung of mice to induce radiation pneumonitis. For inhibition of AQP4, 200mg/kg of TGN-020 was administered i.p. one time per 2days post-irradiation. Blockade of AQP4 with TGN-020 resulted in the inhibition of inflammatory cell infiltration and the downregulation of inflammatory cytokines (IL-6, IL-17, and TGF-β), chemokines (MIP1a and MCP1), fibrosis-related (Col3al and Fn1), and M2 macrophage marker (Arg1) post-irradiation. Immunofluorescence staining indicated that there was significant fewer M2 macrophage infiltration in the irradiated lung tissues from mice treated with TGN-020. Additionally, depletion of macrophages with liposome clodronate resulted in alleviated lung injury induced by irradiation. Furthermore, adoptive transfer of M1 or M2 macrophages into clodronate-treated mice was performed. The results showed that the administration of M2 macrophages fully reversed the clodronate-induced beneficial effect on inflammation score, thickness, and fibrosis. However, transfer of M1 macrophages only impacted the inflammation score and thickness and did not affect lung fibrosis. AQP4 blockade alleviated the development and severity of irradiated lung damage. This was associated with attenuated infiltration of inflammatory cell, decreased production of pro-inflammatory cytokines, and inhibited activation of M2 macrophages.

Astragaloside IV Inhibits Cigarette Smoke-Induced Pulmonary Inflammation in Mice.

The aim of this study was to investigate the effects of Astragaloside IV (AS) on cigarette smoke (CS)-induced chronic obstructive pulmonary disease (COPD). Our results showed that AS alleviated CS-induced pathological injury in lung tissue. AS also increased superoxide dismutase (SOD) and reduced the level of malondialdehyde (MDA) in serum and lung. AS also reduced cytokines including tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β) in serum and lung. More, AS significantly reduced the protein expression of JAK3/STAT3/NF-κB pathway in CS-induced mice. In vitro, cigarette smoke extract (CSE) stimulation exposed to normal human bronchial epithelial (HBE) cells. Results further confirmed that AS significantly inhibited the protein levels of JAK3/STAT3/NF-κB pathway in CSE-induced HBE. Our result showed that AS might effectively ameliorate COPD via JAK3/STAT3/NF-κB pathway.

Development of novel NEMO-binding domain mimetics for inhibiting IKK/NF-κB activation.

Nuclear factor κB (NF-κB) is a transcription factor important for regulating innate and adaptive immunity, cellular proliferation, apoptosis, and senescence. Dysregulation of NF-κB and its upstream regulator IκB kinase (IKK) contributes to the pathogenesis of multiple inflammatory and degenerative diseases as well as cancer. An 11–amino acid peptide containing the NF-κB essential modulator (NEMO)-binding domain (NBD) derived from the C-terminus of β subunit of IKK, functions as a highly selective inhibitor of the IKK complex by disrupting the association of IKKβ and the IKKγ subunit NEMO. A structure-based pharmacophore model was developed to identify NBD mimetics by in silico screening. Two optimized lead NBD mimetics, SR12343 and SR12460, inhibited tumor necrosis factor α (TNF-α)- and lipopolysaccharide (LPS)-induced NF-κB activation by blocking the interaction between IKKβ and NEMO and suppressed LPS-induced acute pulmonary inflammation in mice. Chronic treatment of a mouse model of Duchenne muscular dystrophy (DMD) with SR12343 and SR12460 attenuated inflammatory infiltration, necrosis and muscle degeneration, demonstrating that these small-molecule NBD mimetics are potential therapeutics for inflammatory and degenerative diseases.

HMGB1 mediates HAdV-7 infection-induced pulmonary inflammation in mice

Human adenovirus (HAdV) is a common respiratory pathogen in children, with no safe and effective treatment currently available. HAdV type 7 (HAdV-7), in particular, causes severe pediatric pneumonia with a high incidence of sequelae and mortality. Clinical data and animal experiments suggest that HAdV-7-induced pneumonia promotes cell necrosis, releasing a large number of inflammatory mediators. In recent years, the high mobility group box-1 (HMGB1) protein, released by necrotic cells, has been shown to play important roles in several viral infections. Here, we show that HMGB1 levels gradually increased in the media supernatants of HAdV-7 infected A549 cells, starting at 12 h post-infection. In vivo, HMGB1 levels in BALF and mRNA levels in lung tissues significantly increased after 3 days of HAdV-7 infection. Among the HMGB1 receptor genes, TLR-4 and TLR-9 expression increased, and so did the receptor for advanced glycation end-products (RAGE). Interestingly, NF-κB levels also increased concomitantly. Conversely, when HMGB1 was blocked, the pathological scores from lung tissues, inflammatory mediator levels, and viral copy number all were reduced significantly; in addition, HMGB1-related signaling pathway molecules, namely TLR-4, TLR-9, RAGE, and NF-κB were also reduced. We conclude that HMGB1 promotes HAdV-7 replication and signals through TLR-4, TLR-9, and RAGE receptors to activate NF-κB, stimulating the release of inflammatory mediators and contributing to adenoviral pathology. Thus, HMGB1 could be used as a therapeutic target in HAdV-7 infection.

6% Hydroxyethyl starch (HES 130/0.4) diminishes glycocalyx degradation and decreases vascular permeability during systemic and pulmonary inflammation in mice

BackgroundIncreased vascular permeability is a pathophysiological hallmark of sepsis and results in increased transcapillary leakage of plasma fluid, hypovolemia, and interstitial edema formation. 6% hydroxyethyl starch (HES 130/0.4) is commonly used to treat hypovolemia to maintain adequate organ perfusion and oxygen delivery. The present study was designed to investigate the effects of 6% HES 130/0.4 on glycocalyx integrity and vascular permeability in lipopolysaccharide (LPS)-induced pulmonary inflammation and systemic inflammation in mice.Methods6% HES 130/0.4 or a balanced electrolyte solution (20 ml/kg) was administered intravenously 1 h after cecal ligation and puncture (CLP) or LPS inhalation. Sham-treated animals receiving 6% HES 130/0.4 or the electrolyte solution served as controls. The thickness of the endovascular glycocalyx was visualized by intravital microscopy in lung (LPS inhalation model) or cremaster muscle (CLP model). Syndecan-1, hyaluronic acid, and heparanase levels were measured in blood samples. Vascular permeability in the lungs, liver, kidney, and brain was measured by Evans blue extravasation.ResultsBoth CLP induction and LPS inhalation resulted in increased vascular permeability in the lung, liver, kidney, and brain. 6% HES 130/0.4 infusion led to significantly reduced plasma levels of syndecan-1, heparanase, and hyaluronic acid, which was accompanied by a preservation of the glycocalyx thickness in postcapillary venules of the cremaster (0.78 ± 0.09 μm vs. 1.39 ± 0.10 μm) and lung capillaries (0.81 ± 0.09 μm vs. 1.49 ± 0.12 μm).ConclusionsThese data suggest that 6% HES 130/0.4 exerts protective effects on glycocalyx integrity and attenuates the increase of vascular permeability during systemic inflammation.

A novel glycocluster molecule prevents timothy-induced allergic airway inflammation in mice.

Allergen-specific immunotherapy (SIT) effectively alleviates type I allergic diseases characterized by T helper (Th)2-type immunity. Our recent studies have shown that a synthetic trivalent glycocluster, triacedimannose (TADM), suppresses the Th2-type allergic inflammation. The aim of this study was to compare TADM with two well-known adjuvants, unmethylated cytosine-phosphate-guanine oligodeoxynucleotide (CpG) and monophosphoryl lipidA (MPLA) in a grass allergen-induced chronic allergic inflammation model in mice. Female BALB/c mice were intranasally sensitized with 50μL of timothy grass pollen extract (TE) twice a week for a period of 15weeks. Therapeutic intranasal treatments were then performed once a week after the tenth intranasal TE instillation using TADM (10 or 25μg/50μL), CpG-ODN (20μg/50μL) or MPLA (2μg/50μL). Groups of 9-10 animals per treatment were killed 24hours after the last timothy dosage. Blood, bronchoalveolar lavage (BAL) fluids and lung biopsies were taken for subsequent analysis. When mice were repeatedly exposed to TE for 15weeks, the number of eosinophils and lymphocytes increased in the BAL fluids. The eosinophil and lymphocyte counts decreased dose-dependently and were practically abolished in the mice treated with TADM. Treatments with MPLA or CpG significantly increased the numbers of neutrophils, while CpG nonsignificantly decreased eosinophilia compared to timothy exposure. A novel synthetic glycocluster molecule inhibited the development of grass-induced eosinophilic pulmonary inflammation in mice when administrated in the airways. This compound could be a candidate to be used either as an adjuvant in SIT or as a topical anti-inflammatory treatment.

Standardized Herbal Formula PM014 Inhibits Radiation-Induced Pulmonary Inflammation in Mice

Radiation therapy is widely used for thoracic cancers. However, it occasionally causes radiation-induced lung injuries, including pneumonitis and fibrosis. Chung-Sang-Bo-Ha-Tang (CSBHT) has been traditionally used to treat chronic pulmonary disease in Korea. PM014, a modified herbal formula derived from CSBHT, contains medicinal herbs of seven species. In our previous studies, PM014 exhibited anti-inflammatory effects in a chronic obstructive pulmonary disease model. In this study, we have evaluated the effects of PM014 on radiation-induced lung inflammation. Mice in the treatment group were orally administered PM014 six times for 2 weeks. Effects of PM014 on radiation pneumonitis were evaluated based on histological findings and differential cell count in bronchoalveolar lavage fluid. PM014 treatment significantly inhibited immune cell recruitment and collagen deposition in lung tissue. Normal lung volume, evaluated by radiological analysis, in PM014-treated mice was higher compared to that in irradiated control mice. PM014-treated mice exhibited significant changes in inspiratory capacity, compliance and tissue damping and elastance. Additionally, PM014 treatment resulted in the downregulation of inflammatory cytokines, chemokines, and fibrosis-related genes and a reduction in the transforming growth factor-β1-positive cell population in lung tissue. Thus, PM014 is a potent therapeutic agent for radiation-induced lung fibrosis and inflammation.

α-bisabolol-loaded lipid-core nanocapsules reduce lipopolysaccharide-induced pulmonary inflammation in mice.

Acute respiratory distress syndrome (ARDS) is a severe clinical condition of respiratory failure due to an intense inflammatory response with different etiologies. Despite all efforts, therapy remains limited, and ARDS is still associated with high mortality and morbidity. Plants can provide a vast source of active natural products for the discovery of new drugs. α-bisabolol (α-bis), a constituent of the essential oil from chamomile, has elicited pharmacological interest. However, the molecule has some limitations to its biological application. This study was conducted to develop a drug delivery system using lipid-core nanocapsules (LNCs) to improve the anti-inflammatory effects of orally administered α-bis. α-bis-loaded LNCs (α-bis-LNCs) were prepared by interfacial deposition of poly(ε-caprolactone) and orally administered in a mouse model of ARDS triggered by an intranasal administration of lipopolysaccharide (LPS). We found that α-bis-LNCs (30, 50, and 100 mg kg−1) significantly reduced airway hyperreactivity (AHR), neutrophil infiltration, myeloperoxidase activity, chemokine levels (KC and MIP-2), and tissue lung injury 18 hours after the LPS challenge. By contrast, free α-bis failed to modify AHR and neutrophil accumulation in the bronchoalveolar lavage effluent and lung parenchyma and inhibited elevation in the myeloperoxidase and MIP-2 levels only at the highest dose. Furthermore, only α-bis-LNCs reduced LPS-induced changes in mitogen-activated protein kinase signaling, as observed by a significant reduction in phosphorylation levels of ERK1/2, JNK, and p38 proteins. Taken together, our results clearly show that by using LNCs, α-bis was able to decrease LPS-induced inflammation. These findings may be explained by the robust increase of α-bis concentration in the lung tissue that was achieved by the LNCs. Altogether, these results indicate that α-bis-LNCs should further be investigated as a potential alternative for the treatment of ARDS.

The effects of electronic cigarette aerosol exposure on inflammation and lung function in mice.

Electronic cigarette usage is increasing worldwide, yet there is a paucity of information on the respiratory health effects of electronic cigarette aerosol exposure. This study aimed to assess whether exposure to electronic cigarette (e-cigarette) aerosol would alter lung function and pulmonary inflammation in mice and to compare the severity of any alterations with mice exposed to mainstream tobacco smoke. Female BALB/c mice were exposed for 8 wk to tobacco smoke, medical air (control), or one of four different types of e-cigarette aerosol. E-cigarette aerosols varied depending on nicotine content (0 or 12 mg/ml) and the main excipient (propylene glycol or glycerin). Twenty-four hours after the final exposure, we measured pulmonary inflammation, lung volume, lung mechanics, and responsiveness to methacholine. Mice exposed to tobacco cigarette smoke had increased pulmonary inflammation and responsiveness to methacholine compared with air controls. Mice exposed to e-cigarette aerosol did not have increased inflammation but did display decrements in parenchymal lung function at both functional residual capacity and high transrespiratory pressures. Mice exposed to glycerin-based e-cigarette aerosols were also hyperresponsive to methacholine regardless of the presence or absence of nicotine. This study shows, for the first time, that exposure to e-cigarette aerosol during adolescence and early adulthood is not harmless to the lungs and can result in significant impairments in lung function.