Post-staining Raman analysis of histological sections following decolorization.

Hematoxylin and eosin (HE) staining of tissue sections is a powerful tool for observing changes in the tissue structure and is used as the most fundamental and vital technique in histology. However, xenobiotics such as polymers and inorganic or organic materials have low dyeability, making it difficult to observe the distribution of materials across tissues. Raman spectroscopy is an advantageous technique for identifying materials in tissues using spectroscopic fingerprints by laser irradiation without staining. In this study, we developed a combined method for morphological observation and Raman spectral acquisition on the identical tissue slide by employing a decolorization step to remove eosin-induced fluorescence in HE-stained samples. Our method eliminated the fluorescence background and allowed the identical-field pathological observation, enabling simultaneous identification of biological responses and materials in tissues.

Co-exposure of peptidoglycan and heat-inactivated Asian sand dust exacerbates ovalbumin-induced allergic airway inflammation in mice.

AIMS: Asian sand dust (ASD) comprises soil particles, microorganisms, and various chemical components. We examined whether peptidoglycan (PGN), a structural cell wall component of Gram-positive bacteria, exacerbates ASD-induced allergic airway inflammation in mice. METHODS: The ASD (median diameter ∼4 µm) used was a certified reference material from the National Institute for Environmental Studies in Japan, derived from Gobi Desert surface soil collected in 2011. BALB/c mice were intratracheally exposed to PGN, heat-inactivated ASD (H-ASD), and ovalbumin (OVA), individually and in combination. Twenty-four hours after the final intratracheal administration, bronchoalveolar lavage fluid (BALF) and serum samples were collected. Inflammatory cell count, cytokine levels in the BALF, OVA-specific immunoglobulin levels in the serum, and pathological changes in the lungs were analyzed. RESULTS AND DISCUSSION: After OVA + PGN + H-ASD treatment, the number of eosinophils, neutrophils, and macrophages in the BALF and of eosinophils in the lung tissue was significantly higher than that after OVA + PGN or OVA + H-ASD treatment. Moreover, levels of chemokines and cytokines associated with eosinophil recruitment and activation were significantly higher in the BALF of this group than in that of the OVA + PGN group, and tended to be higher than those in the OVA + H-ASD group. Pathological changes in the lungs were most severe in mice treated with OVA + PGN + H-ASD. CONCLUSIONS: Our results indicate that PGN is involved in the exacerbation of ASD-induced allergic airway inflammation in mice. Thus, inhalation of ASD containing Gram-positive bacteria may trigger allergic bronchial asthma.

Effects of co-exposure of lipopolysaccharide and ß-glucan (Zymosan A) in exacerbating murine allergic asthma associated with Asian sand dust.

During the 2000s, Asian sand dust (ASD) was implicated in the increasing prevalence of respiratory disorders, including asthma. We previously demonstrated that a fungus from ASD aerosol exacerbated ovalbumin (OVA)-induced airways inflammation. Exposure to heat-inactivated ASD (H-ASD) and either Zymosan A (ZymA, containing ß-glucan) or lipopolysaccharide (LPS) exacerbated allergic airways inflammation in a mouse model, but the effects of co-exposure of LPS and ß-glucan are unclear. We investigated the effects of co-exposure of LPS and ZymA in OVA-induced allergic airways inflammation with ASD using BALB/c mice. Exposure to OVA + LPS enhanced the recruitment of inflammatory cells to the lungs, particularly neutrophils; exposure to OVA + LPS + H-ASD potentiated this effect. Exposure to OVA + ZymA + H-ASD stimulated the recruitment of inflammatory cells to the lungs, particularly eosinophils, and serum levels of OVA-specific IgE and IgG1 antibodies, whereas exposure to OVA + ZymA did not affect most indicators of lung inflammation. Although exposure to OVA + LPS + ZymA + H-ASD affected a few allergic parameters additively or synergistically, most allergic parameters in this group indicated the same level of exposure to OVA + LPS + H-ASD or OVA + ZymA + H-ASD. These results suggest that LPS and ZymA play different roles in allergic airways inflammation with ASD; LPS mainly enhances neutrophil recruitment through H-ASD, and ZymA enhances eosinophil recruitment through H-ASD.

Effect of the hand antiseptic agents benzalkonium chloride, povidone-iodine, ethanol, and chlorhexidine gluconate on atopic dermatitis in NC/Nga mice.

Antiseptic agents can cause skin irritation and lead to severe problems, especially for individuals with atopic diatheses. We investigated the effect of 4 different antiseptic agents using an atopic dermatitis (AD) model mouse. NC/Nga mice were subcutaneously injected with mite allergen (Dp) to induce AD-like skin lesions (ADSLs), and an application of 0.2% (w/v) benzalkonium chloride (BZK), 10% (w/v) povidone-iodine (PVP-I), 80% (v/v) ethanol (Et-OH), or 0.5% (v/v) chlorhexidine gluconate (CHG) was applied to the ear envelope. BZK induced a significant increase in the severity of the clinical score, infiltration of inflammatory cells, local expression of inflammatory cytokines in subcutaneous tissue, and total serum immunoglobulin (Ig) E. PVP-I increased the clinical score, number of mast cells, and production of inflammatory cytokines, and total serum IgE. Et-OH increased the clinical score and number of inflammatory cells, but showed no effect on serum IgE levels. No differences in any parameters were observed between CHG and the vehicle. Collectively, the results suggest the severity of the ADSL was related in part to the strength of the immunoreaction. These findings suggest that CHG could offer the lowest risk of inducing ADSL in individuals with atopic dermatitis and that medical staff and food handlers with AD could benefit from its use.

The alkylphenols 4-nonylphenol, 4-tert-octylphenol and 4-tert-butylphenol aggravate atopic dermatitis-like skin lesions in NC/Nga mice.

Phthalate esters in plastics act as adjuvants for immunoglobulin production, which aggravates allergic disease. However, the effects of alkylphenols (used as plasticizers and surfactants) on atopic dermatitis have not been studied in detail. Therefore, the goal of the present study was to investigate the effects of the alkylphenols 4-nonylphenol (NP), 4-tert-octylphenol (OP) and 4-tert-butylphenol (BP) in a murine model of atopic dermatitis. NC/Nga mice were intraperitoneally administered NP, OP or BP and were subcutaneously injected with mite allergen in one ear to induce atopic dermatitis-like skin lesions (ADSLs). The condition of the skin was observed, and the levels of immunoglobulin in serum and inflammatory cytokines in lesions were determined. NP exacerbated mite allergen-induced ADSLs according to dose. OP and BP also significantly exacerbated skin lesions but not as a function of dose. Alkylphenols tended to increase the levels of IgE and antigen-specific IgG1 in serum. Further, the treatment of the alkylphenols increased the expression in lesions of inflammatory cytokines, interleukin-4 and monocyte chemotactic protein-3. Thymic stromal lymphopoietin levels increased according to ADSL severity. In contrast, the levels of the T-helper 1 cytokines (interleukin-18 and interferon-gamma) decreased. NP, OP or BP may enhance T-helper 2-type immune responses in NC/Nga mice, which aggravates mite allergen-induced ADSLs. Therefore, the uptake of very low levels of alkylphenols may contribute to the increase in the incidence of atopic dermatitis.

Effects of oral administration of di-(2-ethylhexyl) and diisononyl phthalates on atopic dermatitis in NC/Nga mice.

CONTEXT: Subcutaneous injection of low dose of phthalates causes adjuvant effects on immunoglobulin production. Moreover, intraperitoneal injection of di-(2-ethylhexyl) phthalate (DEHP) and diisononyl phthalate (DINP) at doses lower than the no-observed-adverse-effect level (NOAEL) causes aggravation of atopic dermatitis-like skin lesions (ADSLs) in mouse models. However, the effects of oral exposure to these phthalates, including their effect on atopic dermatitis (AD) symptoms, remain unclear. OBJECTIVE: To investigate the effects of oral administration of DEHP and DINP at doses lower than the NOAEL on AD in an NC/Nga mouse model. MATERIALS AND METHODS: NC/Nga mice were subcutaneously injected with mite-allergen (Dermatophagoides pteronyssinus) to induce ADSLs and orally administered varying doses of DEHP (0, 8.3, 166.3 or 3325 µg/animal) or DINP (0, 6.6, 131.3 or 2625 µg/animal) once a week for four weeks. Skin disease symptomatology was subsequently evaluated and immunoglobulin production levels in serum and inflammatory cytokine levels in lesion sites were measured. RESULTS: Oral administration of low doses of both DEHP and DINP tended to increase infiltration of eosinophils; degranulation of mast cells and local expression of inflammatory cytokines, interleukin-13 and macrophage inflammatory protein-1 alpha in subcutaneous tissue, whereas DINP administration tended to aggravate allergen-induced ADSL production. CONCLUSIONS: Oral administration of both DEHP and DINP at doses lower than the NOAEL tends to increase the allergic response in animal AD models, but only DINP administration slightly aggravates allergen-induced ADSL production.

Organic chemicals in diesel exhaust particles enhance picryl chloride-induced atopic dermatitis in NC/Nga mice.

BACKGROUND: Diesel exhaust particles (DEP) have been reported to worsen allergic airway inflammation in mice. Recently, the organic chemical components of DEP (DEP-OC) were found to be important contributors to the aggravation of allergic airway inflammation in mice. The purpose of this study was to examine the effects of DEP-OC on atopic dermatitis (AD)-like skin lesions induced by picryl chloride (PiCl) in NC/Nga mice. METHODS: DEP were extracted with benzene/ethanol, and the soluble organic fraction formed the DEP-OC. NC/Nga male mice received simultaneous application of DEP-OC and/or PiCl on their ears once a week for 9 or 3 weeks. We evaluated skin lesions by noting scaling, eruption, excoriation, erosion, hemorrhage, pathologic changes, production of cytokines, and IgE level in the serum. RESULTS: PiCl application alone produced progressively severe AD-like skin lesions. The application of PiCl plus DEP-OC resulted in a marked worsening of skin lesions in the early stages of AD. Moreover, mast cell counts significantly increased in the subcutaneous tissue. Administration of PiCl combined with DEP-OC resulted in a greater increase in the local expression of interleukin-4, keratinocyte chemoattractant, and neutrophils in subcutaneous tissue compared with PiCl treatment alone. In contrast, the combination treatment produced lower levels of IFN-γ compared with PiCl treatment alone. CONCLUSIONS: DEP-OC application to the skin aggravated PiCl-induced AD. This aggravation may be due to activation of the Th2-associated immune responses by the organic chemicals in DEP.

Titanium dioxide nanoparticles aggravate atopic dermatitis-like skin lesions in NC/Nga mice.

Titanium dioxide (TiO(2)) nanoparticles are produced abundantly and used ubiquitously in various cosmetic products. However, it remains to be determined whether transdermal exposure to TiO(2) nanoparticles affects atopic dermatitis (AD), which has been increasing in developed countries. We investigated the effects of different sized TiO(2) nanoparticles on AD-like skin lesions induced to mite allergen in NC/Nga mice assumed to show skin barrier dysfunction/defect. Male mice were injected intradermally with TiO(2) nanoparticles of three sizes (15, 50, or 100 nm) and/or mite allergen into their right ears. We evaluated clinical scores, ear thickening, histological findings and the protein expression of T helper (Th) 1 and Th2 cytokines in the ear, and the levels of Ig and histamine in serum. TiO(2) nanoparticles aggravated AD-like skin lesions related to mite allergen in NC/ Nga mice. The enhancing effects are paralleled by the overproduction of IL-4 in the skin, the levels of total IgE and histamine in serum regarding the overall trend. In contrast, TiO(2) nanoparticles decreased the local expression of IFN-gamma in the presence of allergen. Additionally, TiO(2) nanoparticles alone significantly increased histamine levels in serum and IL-13 expression in the ear. However, different effects related to the size differences of TiO(2) nanoparticles were not observed. In conclusion, exposure to TiO(2) nanoparticles under skin barrier dysfunction/defect can exacerbate AD symptoms through Th2-biased immune responses. Furthermore, TiO(2) nanoparticles can play a significant role in the initiation and/or progression of skin diseases following the barrier dysfunction/defect by histamine release even in the absence of allergen.

Effects of maternal exposure to di-(2-ethylhexyl) phthalate during fetal and/or neonatal periods on atopic dermatitis in male offspring.

BACKGROUND: Di-(2-ethylhexyl) phthalate (DEHP) has been widely used in polyvinyl chloride products and is ubiquitous in developed countries. Although maternal exposure to DEHP during fetal and/or neonatal periods reportedly affects reproductive and developmental systems, its effects on allergic diseases in offspring remain to be determined. OBJECTIVES: In the present study, we examined whether maternal exposure to DEHP during fetal and/or neonatal periods in NC/Nga mice affects atopic dermatitis-like skin lesions related to mite allergen in offspring. METHODS: We administered DEHP at a dose of 0, 0.8, 4, 20, or 100 microg/animal/week by intraperitoneal injection into dams during pregnancy (gestation days 0, 7, and 14) and/or lactation (postnatal days 1, 8, and 15). Eight-week-old male offspring of these treated females were injected intradermally with mite allergen into their right ears. We then evaluated clinical scores, ear thickening, histologic findings, and protein expression of eotaxin in the ear. RESULTS: Maternal exposure to a 100-microg dose of DEHP during neonatal periods, but not during fetal periods, enhanced atopic dermatitis-like skin lesions related to mite allergen in males. The results were concomitant with the enhancement of eosinophilic inflammation, mast cell degranulation, and protein expression of eotaxin in overall trend. CONCLUSION: Maternal exposure to DEHP during neonatal periods can accelerate atopic dermatitis-like skin lesions related to mite allergen in male offspring, possibly via T helper 2 (T(H)2)-dominant responses, which can be responsible, at least in part, for the recent increase in atopic dermatitis.

Effects of asian sand dust, Arizona sand dust, amorphous silica and aluminum oxide on allergic inflammation in the murine lung.

The aggravating effects of Asian sand dust (SD) and related minerals on the allergic inflammation were examined in the murine lungs. The toxic materials adsorbed onto Asian SD, Arizona SD were inactivated by heat-treatment. ICR mice were administered mineral samples (0.1 mg/mouse) and/or ovalbumin (OVA) (1 microg/mouse) - normal saline (control), Asian SD, Arizona SD, SiO2, Al2O3, OVA, OVA + Asian SD, OVA + Arizona SD, OVA + SiO2, and OVA + Al2O3 - intratracheally four times at two-week intervals. All samples tested enhanced eosinophil recruitment induced by ovalbumin in the submucosa of the airway, which has a goblet cell proliferation in the bronchial epithelium. Arizona SD alone caused a slight increase of neutrophils in bronchoalveolar lavage fluids along with pro-inflammatory mediators, such as keratinocyte chemoattractant, but Asian SD alone or Al2O3 alone showed no effect. The test particles, except Al2O3, synergistically increased the numbers of eosinophils in BALF induced by ovalbumin. In particular, Arizona SD and SiO2 synergistically increased the eosinophil relevant cytokine and chemokine, such as IL-5 and monocyte chemotactic protein (MCP)-3. The aggravating effects of the samples were dependent on the SiO2 content. All samples tested also induced the adjuvant effects to specific IgG1 production by OVA. These results suggest that the aggravated allergic inflammation by mineral dusts may be due to the mineral elements (mainly SiO2). The enhancement by Arizona SD may be mediated, at least partially, by the increased expression of IL-5 and MCP-3 and also by the modulated expression of IL-5 and MCP-3.

Gene expression analysis of murine lungs following pulmonary exposure to Asian sand dust particles.

The respiratory health impact of Asian sand dust events originating in the deserts of China has become a concern within China and in its neighboring countries. We examined the effects of Asian sand dust particles (ASDPs) on gene expression in the murine lung using microarray analysis and elucidated the components responsible for lung inflammation. Male ICR mice were intratracheally administrated ASDPs, heat-treated ASDPs (ASDP-F, lipopolysaccaride [LPS], or beta-glucan free), or kaolin particles. We performed microarray analysis for murine lungs, the results of which were confirmed by quantitative reverse transcription-polymerase chain reaction (RT-PCR). We also assessed the protein expression and histologic changes. Exposure to ASDP, ASDP-F, or kaolin upregulated (>2-fold) 112, 36, or 9 genes, respectively, compared with vehicle exposure. In particular, ASDP exposure markedly enhanced inflammatory response-related genes, including chemokine (C-X-C motif) ligand 1/keratinocyte-derived chemokine, chemokine (C-X-C motif) ligand 2/macrophage inflammatory protein-2, chemokine (C-C motif) ligand 3/macrophage inflammatory protein-1alpha, and chemokine (C-X-C motif) ligand 10/interferon-gamma-inducible protein-10 (>6-fold). The results were correlated with those of the quantitative RT-PCR and the protein expression analyses in overall trend. In contrast, exposure to ASDP-F attenuated the enhanced expression of these proinflammatory molecules. Kaolin exposure increased the expression of genes and proteins for the chemokines. In histopathologic changes, exposure to ASDP prominently enhanced pulmonary neutrophilic inflammation, followed by kaolin and ASDP-F exposure in the order. Taken together, exposure to ASDP causes pulmonary inflammation via the expression of proinflammatory molecules, which can be attributed to LPS and beta-glucan absorbed in ASDPs. Furthermore, microarray analysis should be effective for identifying potentially novel genes, sensitive biomarkers, and pathways involved in the health effects of the exposure to environmental particles (e.g., ASDPs).

Di-(2-ethylhexyl) phthalate enhances atopic dermatitis-like skin lesions in mice.

Di-(2-ethylhexyl) phthalate (DEHP) has been widely used in polyvinyl chloride products and has become ubiquitous in the developed countries. DEHP reportedly displays an adjuvant effect on immunoglobulin production. However, it has not been elucidated whether DEHP is associated with the aggravation of atopic dermatitis. We investigated the effects of DEHP on atopic dermatitis-like skin lesions induced by mite allergen in NC/Nga mice. NC/Nga male mice were injected intradermally with mite allergen on their right ears. In the presence of allergen, DEHP (0, 0.8, 4, 20, or 100 microg) was administered by intraperitoneal injection. We evaluated clinical scores, ear thickening, histologic findings, and the protein expression of chemokines. Exposure to DEHP at a dose of 0.8-20 microg caused deterioration of atopic dermatitis-like skin lesions related to mite allergen; this was evident from macroscopic and microscopic examinations. Furthermore, these changes were consistent with the protein expression of proinflammatory molecules such as macrophage inflammatory protein-1alpha (MIP-1alpha) and eotaxin in the ear tissue in overall trend. In contrast, 100 microg DEHP did not show the enhancing effects. These results indicate that DEHP enhances atopic dermatitis-like skin lesions at hundred-fold lower levels than the no observed adverse effect level determined on histologic changes in the liver of rodents. DEHP could be at least partly responsible for the recent increase in atopic dermatitis.

Enhancement of mite allergen-induced eosinophil infiltration in the murine airway and local cytokine/chemokine expression by Asian sand dust.

Data on the effects of sand dust toward allergic asthma produced by indoor allergens, such as house dust mites, are not currently available. This study was undertaken to clarify the role of Asian sand dust on mite allergen, Dermatophagoides farinae (D. farinae)-induced eosinophilic inflammation in the murine lung, using sand dusts from the Maowusu Desert (Inner Mongolia) (SD-1) and the Tengger Desert (China) (SD-2). ICR mice were intratracheally administered saline; SD-1 alone; SD-2 alone; D. farinae alone; D. farinae + SD-1; and D. farinae + SD-2, 4 times at 2-wk intervals. The two sand dusts enhanced infiltration of eosinophil in the airway, along with goblet-cell proliferation related to D. farinae. The degree of eosinophil infiltration induced with SD-2 was greater than with SD-1. The SD-1, which contained higher amounts of beta-glucan, increased the expression of interferon (IFN)-gamma in bronchoalveolar lavage fluids (BALF) with or without D. farinae, but SD-2 did not. Synergistically or cumulatively elevated levels of interleukin (IL)-5, eotaxin, and monocyte chemotactic protein in BALF related to D. farinae were higher with D. farinae + SD-2 than with D. farinae + SD-1. These results suggest that increased cytokine and chemokines in BALF play an important role in the enhancement of eosinophil infiltration in the airway induced by D. farinae + sand dusts. The reduced eosinophil infiltration in the SD-1-treated mice could be due to suppression of Th-2 cytokine and eotaxin via interferon-gamma induced by microbial materials, such as beta-glucan.

Co-exposure to zymosan A and heat-inactivated Asian sand dust exacerbates ovalbumin-induced murine lung eosinophilia.

BACKGROUND: Epidemiological studies have implicated Asian sand dust (ASD) in the increased prevalence of respiratory disorders, including asthma. It has been observed that fungal elements such as ß-glucan can be adsorbed onto ASD. In the present study, the exacerbating effect of the combined exposure to zymosan A (ZymA) containing yeast ß-glucan and heat-inactivated ASD on ovalbumin (OVA)-induced murine lung eosinophilia was investigated. METHODS: BALB/c mice were repeatedly instilled intratracheally with one of eight immunogenic formulations consisting of various combinations of (1) ZymA, (2) ASD that was briefly heated to remove organic substances (H-ASD), and (3) OVA in normal saline, or each of the above alone. Pathologic changes, cytological alterations in bronchoalveolar lavage fluid (BALF), changes in inflammatory cytokines and chemokines in BALF, and OVA-specific IgE and IgG1 antibodies in serum were investigated. RESULTS: Exposure to ZymA with or without OVA had no effect on most indicators of lung inflammation. Exposure to H-ASD with OVA increased the recruitment of inflammatory cells to the lungs and the serum levels of OVA-specific IgE and IgG1. The combination OVA + ZymA + H-ASD induced a marked recruitment of eosinophils and upregulation of T helper 2 (Th2) cytokines (interleukin [IL]-4 and IL-13), IL-6, eotaxin/CCL11, and monocyte chemotactic protein (MCP)-3/CCL7 in BALF and OVA-specific IgE in serum. This treatment also induced the most severe pathological changes in the lungs of mice. ZymA was found to boost the effects of H-ASD, thereby exacerbating the OVA-induced allergic inflammation, even though ZymA alone did not have such effect. CONCLUSIONS: The results suggest that fungal elements such as ß-1,3-glucan aggravate the allergic inflammation caused by ASD. Our findings may facilitate prophylaxis of some allergic diseases in Asia.

Effects of nano particles on antigen-related airway inflammation in mice.

BACKGROUND: Particulate matter (PM) can exacerbate allergic airway diseases. Although health effects of PM with a diameter of less than 100 nm have been focused, few studies have elucidated the correlation between the sizes of particles and aggravation of allergic diseases. We investigated the effects of nano particles with a diameter of 14 nm or 56 nm on antigen-related airway inflammation. METHODS: ICR mice were divided into six experimental groups. Vehicle, two sizes of carbon nano particles, ovalbumin (OVA), and OVA + nano particles were administered intratracheally. Cellular profile of bronchoalveolar lavage (BAL) fluid, lung histology, expression of cytokines, chemokines, and 8-hydroxy-2'-deoxyguanosine (8-OHdG), and immunoglobulin production were studied. RESULTS: Nano particles with a diameter of 14 nm or 56 nm aggravated antigen-related airway inflammation characterized by infiltration of eosinophils, neutrophils, and mononuclear cells, and by an increase in the number of goblet cells in the bronchial epithelium. Nano particles with antigen increased protein levels of interleukin (IL)-5, IL-6, and IL-13, eotaxin, macrophage chemoattractant protein (MCP)-1, and regulated on activation and normal T cells expressed and secreted (RANTES) in the lung as compared with antigen alone. The formation of 8-OHdG, a proper marker of oxidative stress, was moderately induced by nano particles or antigen alone, and was markedly enhanced by antigen plus nano particles as compared with nano particles or antigen alone. The aggravation was more prominent with 14 nm of nano particles than with 56 nm of particles in overall trend. Particles with a diameter of 14 nm exhibited adjuvant activity for total IgE and antigen-specific IgG1 and IgE. CONCLUSION: Nano particles can aggravate antigen-related airway inflammation and immunoglobulin production, which is more prominent with smaller particles. The enhancement may be mediated, at least partly, by the increased local expression of IL-5 and eotaxin, and also by the modulated expression of IL-13, RANTES, MCP-1, and IL-6.

Role of metallothionein in antigen-related airway inflammation.

Metallothionein (MT) is a protein that can be induced by inflammatory mediators and participates in cytoprotection. However, its role in antigen-related inflammation remains to be established. We determined whether intrinsic MT protects against antigen-related airway inflammation induced by ovalbumin (OVA) in MT-I/II null (MT [-/-]) mice and in corresponding wild-type (WT) mice. MT (-/-) mice and WT mice were intratracheally challenged with OVA (1 mug per body) biweekly four times. Twenty-four hours after the last OVA challenge, significant increases were shown in the numbers of total cells, eosinophils, and neutrophils in bronchoalveolar lavage fluid from MT (-/-) mice than in those from WT mice. The protein level of interleukin-1beta (IL-1beta) was significantly greater in MT (-/-) mice than in WT mice after OVA challenge. Immunohistochemical analysis showed that the formations of 8-oxy-deoxyguanosine and nitrotyrosine in the lung were more intense in MT (-/-) mice than in WT mice after OVA challenge. These results indicate that endogenous MT is a protective molecule against antigen-related airway inflammation induced by OVA, at least partly, via the suppression of enhanced lung expression of IL-1beta and via the antioxidative properties. Our findings suggest that MT may be a therapeutic target for the treatment of antigen-related airway inflammatory diseases such as bronchial asthma.

Pulmonary toxicity induced by intratracheal instillation of Asian yellow dust (Kosa) in mice.

Asian yellow dust (Kosa) causes adverse respiratory health effects in humans. The objective of this study was to clarify the lung toxicity of Kosa. ICR mice (5 weeks of age) were administered intratracheally with Kosa samples-two samples from Maowusu desert and Shapotou desert, one sample consisted of Shapotou Kosa plus sulfate, and natural Asian dust (NAD) from the atmosphere of Beijing-at doses of 0.05, 0.10 or 0.20mg/mouse at four weekly intervals. The four Kosa samples tested had similar compositions of minerals and concentrations of elements. Instillation of dust particles caused bronchitis and alveolitis in treated mice. The magnitude of inflammation was much greater in NAD-treated mice than in the other particles tested. Increased neutrophils, lymphocytes or eosinophils in bronchoalveolar lavage fluids (BALF) of treated mice were dose dependent. The number of neutrophils in BALF at the 0.2mg level was parallel to the content of ß-glucan in each particle. The numbers of lymphocytes and eosinophils in BALF at the 0.2mg level were parallel to the concentration of SO(4)(2-) in each particle. Pro-inflammatory mediators-such as interleukin (IL)-12, tumor necrosis factor-(TNF)-α, keratinocyte chemoattractant (KC), monocyte chemotactic protein (MCP)-l and macrophage inflammatory protein-(MIP)-lα in BALF-were greater in the treated mice. Specifically, NAD considerably increased pro-inflammatory mediators at a 0.2mg dose. The increased amounts of MlP-lα and TNF-α at 0.2mg dose corresponded to the amount of ß-glucan in each particle. The amounts of MCP-l or IL-12 corresponded to the concentration of sulfate (SO(4)(2-)) at a 0.2mg dose. These results suggest that inflammatory lung injury was mediated by ß-glucan or SO(4)(2-), which was adsorbed into the particles, via the expression of these pro-inflammatory mediators. The results also suggest that the variations in the magnitude of inflammation of the tested Kosa samples depend on the amounts of these toxic materials.

Effect of 15-deoxy-delta 12,14-prostaglandin J2 on acute lung injury induced by lipopolysaccharide in mice.

15-Deoxy-delta(12,14)-prostaglandin J(2) (15d-prostaglandin J(2)) has received attention for its anti-inflammatory properties. The present study investigated the efficacy of 15d-prostaglandin J(2) on acute lung injury induced by lipopolysaccharide in mice. ICR mice were administered with 15d-prostaglandin J(2) (10 microg/kg, 100 microg/kg, or 1 mg/kg) before intratracheal challenge with lipopolysaccharide (125 microg/kg). Treatment with 15d-prostaglandin J(2) did not ameliorate rather enhanced at a dose of 1 mg/kg the neutrophilic lung inflammation and pulmonary edema by lipopolysaccharide. The enhancement was concomitant with the increased lung expression of interleukin-1 beta, macrophage inflammatory protein-1 alpha, and macrophage chemoattractant protein-1. 15d-prostaglandin J(2) increased the nuclear protein expression of peroxisome proliferator-activated receptor (PPAR)-gamma and inhibited the nuclear localization of nuclear factor-kappa B related to lipopolysaccharide. 15d-prostaglandin J(2) increased the phosphorylation of c-Jun in the presence or absence of lipopolysaccharide. Our data suggest that 15d-prostaglandin J(2) may not be useful but potentially harmful for the therapeutic option of acute lung injury.

Complementary DNA microarray analysis in acute lung injury induced by lipopolysaccharide and diesel exhaust particles.

We have recently shown that diesel exhaust particles (DEP) synergistically enhance acute lung injury related to lipopoly-saccharide (LPS) in mice. The present study used cDNA microarray to elucidate the effects of DEP on the global pattern of LPS-related gene expression in the murine lung. The number of genes upregulated >/=2-fold as compared with their expression levels in the vehicle group was greater in the LPS group than in other groups, but treatment with DEP and LPS dramatically increased the number of the genes upregulated >/=6-fold. In particular, gene expression of metallothionein-1 and -2, S100 calcium-binding protein A9, lipocalin 2, and small inducible cytokine B family member 10 was higher by >/=20-fold in the DEP + LPS group than in the vehicle group. These results were concomitant with those obtained by real-time reverse transcription-polymerase chain reaction analysis in the overall trend. Our findings suggest that intense, focused expression of genes such as S100 calcium-binding protein A9, lipocalin 2, and small inducible cytokine B family member 10 relates to the synergistic aggravation of acute lung injury by LPS and DEP rather than weak, broad expression of various genes by exposure of LPS alone.

Nitrogen dioxide air pollution near ambient levels is an atherogenic risk primarily in obese subjects: a brief communication.

Ambient exposure to nitrogen dioxide, a critical air pollutant in developed countries, is positively associated with cardiovascular mortality and morbidity. Although its cardiovascular effects are predominantly shown in patients with high risk of atherogenesis, no studies have elucidated whether daily exposure to nitrogen dioxide air pollution enhances atherogenic metabolisms, primarily in obese subjects who are susceptible to atherogenesis and subsequent cardiovascular diseases. We used male Otsuka Long-Evans Tokushima Fatty (OLETF) rats as obese subjects and Long-Evans Tokushima (LETO) rats as nonobese controls. The animals were continuously exposed to nitrogen dioxide at a concentration of 0, 0.16, 0.8, or 4.0 ppm from 8 weeks of age through 32 weeks. At 40 weeks of age, levels of body weight, triglyceride, and total cholesterol were significantly greater in the OLETF rats than in the LETO rats. A ratio of high-density lipoprotein (HDL) to total cholesterol was significantly smaller in the former than in the latter. In the LETO rats, nitrogen dioxide exposure significantly decreased only the levels of HDL as compared with clean air exposure. In the OLETF rats, however, nitrogen dioxide exposure at a concentration of 0.16 ppm significantly elevated triglyceride concentration and decreased the ratio of HDL to total cholesterol as well as the levels of HDL. Nitrogen dioxide air pollution near ambient levels is an atherogenic risk primarily in obese subjects.