Rie Yanagisawa

Penta- and octa-bromodiphenyl ethers promote proinflammatory protein expression in human bronchial epithelial cells in vitro

Polybrominated diphenyl ethers (PBDEs) are widely used as flame retardants in consumer products. Humans can be exposed to PBDEs mainly through the inhalation of air or dust. Thus, PBDEs can affect respiratory and immune systems. In the present study, we investigated whether PBDEs stimulate bronchial epithelial cells. We examined commercial penta-BDE (DE-71), octa-BDE (DE-79), and deca-BDE (DE-83R). Human bronchial epithelial cells (BEAS-2B) were exposed to each PBDE for 24h. Subsequently, the expression of intercellular adhesion molecule-1 (ICAM-1) and proinflammatory cytokines were investigated. DE-71 and DE-79, but not DE-83R, significantly increased the expression of ICAM-1, interleukin-6 (IL-6), and IL-8 in BEAS-2B. Because these remarkable effects were observed with DE-71, we further investigated the underlying intracellular mechanisms. DE-71 promoted epidermal growth factor receptor (EGFR) phosphorylation. Inhibitors of EGFR-selective tyrosine kinase and p38 mitogen-activated protein kinase effectively blocked the increase of IL-6 and IL-8. Furthermore, antagonists of thyroid hormone receptor and aryl hydrocarbon receptor significantly suppressed the increase in IL-6 and/or IL-8 production. In conclusion, penta- and octa-BDE, but not deca-BDE, might promote the expression of proinflammatory proteins in bronchial epithelial cells possibly by activating protein kinases and/or stimulating nuclear receptors related to subsequent activation of transcriptional factors.

Effects of multi-walled carbon nanotubes on a murine allergic airway inflammation model

The development of nanotechnology has increased the risk of exposure to types of particles other than combustion-derived particles in the environment, namely, industrial nanomaterials. On the other hand, patients with bronchial asthma are sensitive to inhaled substances including particulate matters. This study examined the effects of pulmonary exposure to a type of nano-sized carbon nanotube (multi-walled nanotubes: MWCNT) on allergic airway inflammation in vivo and their cellular mechanisms in vitro. In vivo, ICR mice were divided into 4 experimental groups. Vehicle, MWCNT (50 microg/animal), ovalbumin (OVA), and OVA+MWCNT were repeatedly administered intratracheally. Bronchoalveolar lavage (BAL) cellularity, lung histology, levels of cytokines related to allergic inflammation in lung homogenates/BAL fluids (BALFs), and serum immunoglobulin levels were studied. Also, we evaluated the impact of MWCNT (0.1-1 microg/ml) on the phenotype and function of bone marrow-derived dendritic cells (DC) in vitro. MWCNT aggravated allergen-induced airway inflammation characterized by the infiltration of eosinophils, neutrophils, and mononuclear cells in the lung, and an increase in the number of goblet cells in the bronchial epithelium. MWCNT with allergen amplified lung protein levels of Th cytokines and chemokines compared with allergen alone. MWCNT exhibited adjuvant activity for allergen-specific IgG(1) and IgE. MWCNT significantly increased allergen (OVA)-specific syngeneic T-cell proliferation, particularly at a lower concentration in vitro. Taken together, MWCNT can exacerbate murine allergic airway inflammation, at least partly, via the promotion of a Th-dominant milieu. In addition, the exacerbation may be partly through the inappropriate activation of antigen-presenting cells including DC.

Extract of Perilla frutescens Enriched for Rosmarinic Acid, a Polyphenolic Phytochemical, Inhibits Seasonal Allergic Rhinoconjunctivitis in Humans

Extract of Perilla frutescens enriched for rosmarinic acid, a polyphenolic phytochemical, suppresses allergic immunoglobulin responses and inflammation caused by polymorphonuclear leukocytes (PMNL) in mice. However, few placebo-controlled clinical trials have examined the efficacy and safety of polyphenolic phytochemicals for treatment of allergic inflammatory diseases in humans. The present study determined whether oral supplementation with rosmarinic acid is an effective intervention for patients with seasonal allergic rhinoconjunctivitis (SAR). In this 21-day, randomized, double-blind, age-matched, placebo-controlled parallel group study, patients with mild SAR were treated daily with extract of Perilla frutescens enriched for rosmarinic acid (200 mg [n = 10] or 50 mg [n = 9]) or placebo (n = 10). Patients recorded symptoms daily in a diary. Profiles of infiltrating cells and concentrations of eotaxin, IL-1β, IL-8, and histamine were measured in nasal lavage fluid. Serum IgE concentrations and routine blood tests were also examined. As compared with placebo supplementation, supplementation with extract of Perilla frutescens enriched for rosmarinic acid resulted in a significant increase in responder rates for itchy nose, watery eyes, itchy eyes, and total symptoms (P < 0.05). Active treatment significantly decreased the numbers of neutrophils and eosinophils in nasal lavage fluid (P < 0.05 vs. placebo). Patients reported no adverse events, and no significant abnormalities were detected in routine blood tests. In conclusion, extract of Perilla frutescens enriched for rosmarinic acid can be an effective intervention for mild SAR at least partly through inhibition of PMNL infiltration into the nostrils. Use of this alternative treatment for SAR might reduce treatment costs for allergic diseases.

Effects of airway exposure to nanoparticles on lung inflammation induced by bacterial endotoxin in mice.

Background Although adverse health effects of particulate matter with a diameter of < 100 nm (nanoparticles) have been proposed, molecular and/or experimental evidence for their facilitation of lung inflammation in vivo is not fully defined. Objective In the present study we investigated the effects of nanoparticles on lung inflammation related to bacterial endotoxin [lipopolysaccharide (LPS)] in mice. Results We intratracheally administered vehicle, two sizes (14 nm, 56 nm) of carbon black nanoparticles (4 mg/kg), LPS (2.5 mg/kg), or LPS plus nanoparticles and evaluated parameters for lung inflammation and coagulation. Nanoparticles alone induced slight lung inflammation and significant pulmonary edema compared with vehicle. Fourteen-nanometer nanoparticles intensively aggravated LPS-elicited lung inflammation and pulmonary edema that was concomitant with the enhanced lung expression of interleukin-1β (IL-1β), macrophage inflammatory protein-1α (MIP-1α), macrophage chemoattractant protein-1, MIP-2, and keratinocyte chemoattractant in overall trend, whereas 56-nm nanoparticles did not show apparent effects. Immunoreactivity for 8-hydroxyguanosine, a marker for oxidative stress, was more intense in the lungs from the LPS + 14-nm nanoparticle group than in those from the LPS group. Circulatory fibrinogen levels were higher in the LPS + plus 14-nm nanoparticle group than in the LPS group. Conclusions Taken together, evidence indicates that nanoparticles can aggravate lung inflammation related to bacterial endotoxin, which is more prominent with smaller particles. The enhancement may be mediated, at least partly, via the increased local expression of proinflammatory cytokines and via the oxidative stress. Furthermore, nanoparticles can promote coagulatory disturbance accompanied by lung inflammation.

Repeated pulmonary exposure to single-walled carbon nanotubes exacerbates allergic inflammation of the airway: Possible role of oxidative stress.

The development of nanotechnology has increased the risk of environmental exposure to types of particles other than those derived from combustion, namely, industrial nanomaterials. Patients with bronchial asthma are sensitive to inhaled substances, including particulate matter. This study examined the effects of pulmonary exposure to a type of nano-sized carbon nanotube (single-walled nanotubes (SWCNT)) on allergic airway inflammation and sought their cellular mechanisms. In the in vivo experiments, ICR mice were divided into four experimental groups that were repeatedly administered vehicle, SWCNT (50 microg/animal), ovalbumin (OVA; an allergen), or OVA + SWCNT through an intratracheal route and thereafter assayed. SWCNT aggravated allergen-induced pulmonary inflammation with mucus hyperplasia. SWCNT with allergen amplified lung protein levels of T helper (Th) cytokines and chemokines related to allergy and exhibited adjuvant activity for allergen-specific IgG(1) (and IgE) compared with allergen alone. SWCNT accentuated the level/activity of oxidative stress-related biomarkers in the airways in the presence of allergen. In vitro, SWCNT can partially promote/strengthen the maturation/activation/function of bone marrow-derived dendritic cells (DC). Together, these results suggest that SWCNT can exacerbate murine allergic airway inflammation via enhanced activation of Th immunity and increased oxidative stress. In addition, this exacerbation may be partly through the inappropriate activation of antigen-presenting cells, including DC.

Prenatal exposure to bisphenol A up-regulates immune responses, including T helper 1 and T helper 2 responses, in mice

The effect of prenatal exposure to bisphenol A (BPA) on the immune system in mice was investigated. Virgin female mice were fed varying doses of BPA, on a daily basis, over a period of 18 days commencing on the day of pairing with stud males (day 0). On day 77, their male offspring of 8 weeks were immunized with hen egg lysozyme (HEL). Three weeks later, anti‐HEL immunoglobulin G (IgG) in sera, and proliferative responses of spleen cells to the antigen, were measured. Anti‐HEL IgG2a and interferon‐γ (IFN‐γ), secreted from splenic lymphocytes, were measured as indicators of T helper 1 (Th1) immune responses, while anti‐HEL IgG1 and interleukin‐4 (IL‐4) were measured as indicators of Th2 responses. The results showed that fetal exposure to BPA was followed by significant increases in anti‐HEL IgG as well as antigen‐specific cell proliferation. Both Th1 responses (including anti‐HEL IgG2a and IFN‐γ production) and Th2 responses (including anti‐HEL IgG1 and IL‐4 production) were augmented by prenatal exposure to BPA, although the augmentation of Th1 responses appeared to be greater than that of Th2 responses. Two‐colour flow cytometric analysis showed that mice exposed prenatally to BPA had 29% and 100% more splenic CD3+ CD4+ and CD3+ CD8+ cells, respectively, than control animals. Similar results were obtained from females whose mothers had consumed BPA during pregnancy. These results suggest that prenatal exposure to BPA may result in the up‐regulation of immune responses, especially Th1 responses, in adulthood.

Rosmarinic acid in perilla extract inhibits allergic inflammation induced by mite allergen, in a mouse model

Background Perilla and its constituent rosmarinic acid have been suggested to have anti‐allergic activity. However, few studies have examined the effects on allergic asthma.

Rosmarinic acid inhibits lung injury induced by diesel exhaust particles

Epidemiological and experimental studies have suggested that diesel exhaust particles (DEP) may be involved in recent increases in lung diseases. DEP has been shown to generate reactive oxygen species. Intratracheal instillation of DEP induces lung inflammation and edema in mice. Rosmarinic acid is a naturally occurring polyphenol with antioxidative and anti-inflammatory activities. We investigated the effects of rosmarinic acid on lung injury induced by intratracheal administration of DEP (500 microg/body) in mice. Oral supplementation with administration of rosmarinic acid (2 mg/body for 3 d) inhibited DEP-induced lung injury, which was characterized by neutrophil sequestration and interstitial edema. DEP enhanced the lung expression of keratinocyte chemoattractant (KC), interleukin-1beta, monocyte chemoattractant protein-1, and macrophage inflammatory protein-1alpha, which was inhibited by treatment with rosmarinic acid. DEP enhanced expression of iNOS mRNA and formation of nitrotyrosine and 8-OHdG in the lung, which was also inhibited by rosmarinic acid. These results suggest that rosmarinic acid inhibits DEP-induced lung injury by the reduction of proinflammatory molecule expression. Antioxidative activities of rosmarinic acid may also contribute to its protective effects.

Components of diesel exhaust particles differentially affect Th1/Th2 response in a murine model of allergic airway inflammation

Background Diesel exhaust particles (DEP) can enhance various respiratory diseases. However, it is unclear as to which components in DEP are associated with the enhancement. We investigated the effects of DEP components on antigen‐related airway inflammation, using residual carbonaceous nuclei of DEP after extraction (washed DEP), extracted organic chemicals (OC) in DEP (DEP–OC), and DEP–OC plus washed DEP (whole DEP) in the presence or absence of ovalbumin (OVA).

Murine strain differences in airway inflammation caused by diesel exhaust particles

To elucidate whether immunoglobulin (Ig) E or IgG are involved in the murine asthma model, we compared the pathogenic features of mice that were high IgG responders (C3H/He) with mice that were high IgE responders (BALB/c) after intratracheal instillation of diesel exhaust particles (DEP) and ovalbumin sensitization. Both mouse strains received DEP intratracheally once a week for 5 weeks. After the second injection of DEP, ovalbumin and aluminium hydroxide were injected intraperitoneally. After the last DEP administration, the mice were challenged by exposure to an aerosol of ovalbumin. DEP caused increased IgG1 production and airway hyperresponsiveness after ovalbumin sensitization in C3H/He mice, although IgE production did not change in either strain. Furthermore, in C3H/He mice, the number of eosinophils and goblet cells in the bronchial epithelium, and the expression of interleukin-5 and interleukin-2 were increased by DEP and ovalbumin treatments. In contrast, the pathogenic changes in BALB/c mice were weak, even though the same protocol was used. In conclusion, murine strain differences in response to air pollutants and allergens seem to be related to antigen-specific immunoglobulin G1 production and cytokine expression in the lungs.