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Biomedical subjects

Ken-Ichiro Inoue

Publications and source records attributed to Ken-Ichiro Inoue.

At least 19 recordsLinked to original sources
PubMed2007

Pulmonary exposure to diesel exhaust particles enhances fatty change of the liver in obese diabetic mice.

In epidemiological studies, exposure to ambient particulate matter (PM) has been reported to be positively associated with mortality in subjects with diabetes mellitus. Diesel exhaust particles (DEP) are major constituents of atmospheric PM. However, there is no experimental evidence for the relation of DEP to diabetes mellitus and its complications. We investigated the effects of DEP inoculated intratracheally on diabetic changes and nonalcoholic fatty liver disease (NAFLD) in diabetic obese and control mice. db/db mice and the corresponding nondiabetic db/+m mice received exposure to vehicle or DEP every two weeks. Animals were examined with biochemistry, histology, and immunohistochemistry for hexanoyl-lysine (HEL) in the liver. In the db/+m mice, pulmonary exposure to DEP did not increase levels of aspartate aminotransferase (AST) or alanine aminotransferase (ALT) compared to that to vehicle. In the db/db mice, however, the exposure to DEP increased the levels of AST and ALT compared to that to vehicle. Only in the db/db mice, DEP enhanced the magnitude of steatosis and formation of HEL, a marker of oxidative stress, in the liver compared to vehicle. These results suggest that pulmonary exposure to DEP, PM, enhances steatosis in the liver of obese diabetic subjects possibly via enhanced oxidative stress.

Alanine Transaminase↗
PubMed2006

Effects of nano particles on cytokine expression in murine lung in the absence or presence of allergen.

Particulate matter (PM) can exacerbate allergic airway diseases. Health effects of PM with a diameter of less than 100 nm, called nano particles, have been focused. We have recently demonstrated that carbon nano particles (14, 56 nm) exaggerate allergic airway inflammation in mice. In the present study, we investigated the effects of repeated pulmonary exposure to carbon nano particles on the expression of a variety of cytokines in the absence or presence of allergen in mice. ICR mice were divided into six experimental groups. Vehicle, two sizes of carbon nano particles, ovalbumin (OVA), and OVA + nano particles were administered intratracheally. Nano particles increased the lung protein levels of thymus and activation-regulated chemokine (TARC), macrophage inflammatory protein (MIP)-1alpha, and granulocyte-macrophage colony-stimulating factor (GM-CSF) in the absence or presence of allergen. The enhancement was more prominent with 14 nm of nano particles than with 56 nm of nano particles in overall trend. 14 nm nano particle exposure significantly enhanced the lung expressions of interleukin (IL)-2 and IL-10 in the presence of allergen as compared with allergen exposure. These results suggest that pulmonary exposure to nano particles can induce the lung expression of TARC, MIP-1alpha, GM-CSF in the absence of allergen and can enhance that of TARC, MIP-1alpha, GM-CSF, IL-2, and IL-10 in the presence of allergen. The enhancing effects are more prominent with smaller particles.

Allergens↗
PubMed2006

Effects of diesel exhaust on lung inflammation related to bacterial endotoxin in mice.

We have previously shown that intratracheal instillation of diesel exhaust particles enhances lung inflammation and lung expression of proinflammatory cytokines and chemokines related to bacterial endotoxin (lipopolysaccharide) in mice. The present study was designed to elucidate the effects of inhalation of diesel exhaust on lung inflammation related to lipopolysaccharide. ICR mice were exposed for 12 hr to clean air or diesel exhaust at a soot concentration of 0.3, 1.0, or 3.0 mg/m(3) after intratracheal challenge with 125 microg/kg of lipopolysaccharide. Lung inflammation and lung expression of proinflammatory chemokines such as macrophage chemoattractant protein-1 and keratinocyte chemoattractant were evaluated 24 hr after intratracheal administration. Diesel exhaust inhalation decreased lipopolysaccharide-elicited inflammatory cell recruitment into the bronchoalveolar lavage fluid as compared with clean air inhalation. Histological study demonstrated that exposure to diesel exhaust did not affect lipopolysaccharide-enhanced neutrophil recruitment into the lung parenchyma. Lipopolysaccharide instillation elevated lung expression of macrophage chemoattractant protein-1 and keratinocyte chemoattractant under clean air or diesel exhaust inhalation. However, diesel exhaust exposure did not influence but rather did suppress these levels in the presence of lipopolysaccharide. These results suggest that short-term exposure to diesel exhaust did not exacerbate lung inflammation related to bacterial endotoxin.

Air Pollutants↗
PubMed2006

Pulmonary exposure to diesel exhaust particles enhances coagulatory disturbance with endothelial damage and systemic inflammation related to lung inflammation.

Pulmonary exposure to diesel exhaust particles (DEP) enhances lung inflammation related to bacterial endotoxin (lipopolysaccharide [LPS]) in mice. Severe lung inflammation can reportedly induce coagulatory abnormalities and systemic inflammation. This study examined the effects of components of DEP on lung inflammation, pulmonary permeability, coagulatory changes, systemic inflammatory response, and lung-to-systemic translocation of LPS in a murine model of lung inflammation. ICR mice were divided into six experimental groups that intratracheally received vehicle, LPS (2.5 mg/kg), organic chemicals in DEP (DEP-OC; 4 mg/kg) extracted with dicloromethane), residual carbonaceous nuclei of DEP (washed DEP: 4 mg/kg), DEP-OC + LPS, or washed DEP + LPS. Both DEP components exacerbated lung inflammation, vascular permeability, and the increased fibrinogen and E-selectin levels induced by LPS. With overall trends, the exacerbation was more prominent with washed DEP than with DEP-OC. Washed DEP + LPS significantly decreased activated protein C and antithrombin-III and elevated circulatory levels of interleukin (IL)-6, keratinocyte chemoattractant (KC), and LPS as compared with LPS alone, whereas DEP-OC + LPS elevated IL-6, KC, and LPS without significance. These results show that DEP components, especially washed DEP, amplify the effects if LPS on the respiratory system and suggest that they contribute to the adverse health effects of particulate air pollution on the sensitive populations with predisposing vascular and/or pulmonary diseases, including ischemic vascular diseases and respiratory infection.

Animals↗
PubMed2006

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-1beta (IL-1beta) , macrophage inflammatory protein-1alpha (MIP-1alpha) , 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.

Air Pollutants↗
PubMed2005

The role of toll-like receptor 4 in airway inflammation induced by diesel exhaust particles.

Although several studies have demonstrated that airway exposure to diesel exhaust particles (DEP) induces lung inflammation, the signaling pathways involved in the pathogenesis remain unclear. Toll-like receptors (TLRs) are generally accepted to be pathogen recognition receptors in mammalians. In the present study, we investigated the role of TLR-4 in DEP-induced lung inflammation and cytokine expression in the lung in TLR-4 point mutant (C3H/HeJ) mice and corresponding control (C3H/HeN) mice. Both the types of mice were randomized into four experimental groups that received vehicle or DEP (12 mg/kg body weight) by intratracheal instillation (n = 8-10 in each group). Cellular profile of bronchoalveolar lavage (BAL) fluid, expressions of cytokines and chemokines in the lung, and circulatory fibrinogen levels were evaluated 24 h after the instillation.DEP challenge revealed a significant increase in the numbers of total cells and neutrophils in the BAL fluid as compared to vehicle challenge, however, the numbers were less in C3H/HeJ mice than in C3H/HeN mice. DEP exposure significantly induced the lung expression of interleukin (IL)-1beta, keratinocyte chemoattractant (KC), and macrophage inflammatory protein (MIP)-1alpha when compared to vehicle challenge in both genotypes of mice. In the presence of DEP, the level of MIP-1alpha was significantly lower in C3H/HeJ mice than in C3H/HeN mice, however, the levels of IL-1beta, KC, and fibrinogen showed opposite findings. These results suggest that TLR-4 is one of recognition receptors against DEP in the airways.

Animals↗
PubMed2005

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.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed2005

Protective role of urinary trypsin inhibitor in acute lung injury induced by lipopolysaccharide.

Urinary trypsin inhibitor (UTI), a serine protease inhibitor, has been widely used as a drug for patients with acute inflammatory disorders such as disseminated intravascular coagulation, shock, and pancreatitis. However, direct contribution of UTI to inflammatory diseases has not been established. The present study analyzed acute inflammatory lung injury induced by lipopolysaccharide (LPS) in UTI-deficient (-/-) mice and corresponding wild-type (WT) mice. UTI (-/-) and WT mice were treated intratracheally with vehicle or LPS (125 mug/kg). The cellular profile of bronchoalveolar lavage fluid, lung water content, histology, and expression of proinflammatory molecules in the lung were evaluated. After LPS challenge, both genotypes of mice revealed neutrophilic lung inflammation and pulmonary edema. UTI (-/-) mice, however, showed more prominent infiltration of inflammatory cells and edema than WT mice. After LPS challenge in both genotypes of mice, the lung levels of mRNA and/or protein expression of interleukin-1beta, macrophage inflammatory protein-1alpha, macrophage chemoattractant protein-1, keratinocyte chemoattractant, and intercellular adhesion molecule-1 (ICAM-1) were elevated in both groups, but to a greater extent in UTI (-/-) mice than in WT mice. These results suggest that UTI protects against acute lung injury induced by bacterial endotoxin, at least partly, through the inhibition of the enhanced local expression of proinflammatory cytokines, chemokines, and ICAM-1.

Animals↗
PubMed2005

Cytoprotection by interleukin-6 against liver injury induced by lipopolysaccharide.

The role of interleukin (IL)-6 in inflammatory injury remains controversial. The present study elucidated the role of IL-6 in liver damage during severe inflammation induced by intraperitoneal administration of lipopolysaccharide (LPS; 1 mg/kg) using IL-6 null (-/-) mice and corresponding wild-type (WT) mice. Histological study showed that LPS treatment caused more severe liver injury with centrilobular vacuolation of hepatocytes and neutrophilic infiltration in the liver of IL-6 (-/-) mice; in contrast, neutrophilic infiltration and mild vacuolar change of hepatocytes were found in the liver of LPS-treated WT mice. Protein levels of proinflammatory molecules, such as IL-1beta, macrophage inflammatory protein-1alpha, and macrophage chemoattractant protein-1, in the livers were significantly greater in IL-6 (-/-) mice than in WT mice after LPS challenge. These results directly indicate that IL-6 is protective against liver injury induced by bacterial endotoxin, at least partly, via the modulation of proinflammatory cytokines and chemokines.

Animals↗
PubMed2005

Effects of volatile constituents of a rosemary extract on allergic airway inflammation related to house dust mite allergen in mice.

Perilla leaf extract is known to have anti-inflammatory properties. Recently, we have demonstrated that rosmarinic acid, a polyphenolic liquid component in perilla, inhibits the allergic airway inflammation induced by house dust mites (HDMs) in vivo. The purpose of this study was to evaluate the effects of intratracheal (i.t.) exposure to volatile constituents of a rosemary extract (VR), gaseous components in perilla, on a murine model of allergic asthma induced by HDM. C3H/HeN mice were treated 7 times weekly with i.t. exposure. The HDM allergen challenge elicited a pulmonary eosinophilic inflammation accompanied by an increase in the lung expression of interleukin (IL)-5, IL-13, and eotaxin. VR inhibited increases in the number of eosinophils, neutrophils, and mononuclear cells around the airways and those in the bronchoalveolar lavage fluid. VR exposure also significantly suppressed the expression of IL-13 enhanced by HDM allergen. These results suggest that i.t. exposure to VR can, at least partially, prevent allergic airway inflammation induced by HDM. The preventive effect is associated with inhibition of the enhanced local expression of IL-13.

Animals↗
PubMed2005

Antioxidative role of urinary trypsin inhibitor in acute lung injury induced by lipopolysaccharide.

We have previously demonstrated the protective role of urinary trypsin inhibitor (UTI) against acute inflammatory lung injury induced by lipopolysaccharide (LPS) using UTI-deficient (-/-) mice and corresponding wild-type (WT) mice. The protection was mediated, at least partly, through inhibition of the enhanced local expression of proinflammatory cytokines, chemokines, and intercellular adhesion molecule-1. In the present study, we addressed whether UTI regulates oxidative stress generated by LPS challenge in the lung. UTI (-/-) and WT mice were treated intratracheally with vehicle or LPS (125 microg/kg). After LPS challenge in both genotypes of mice, the lung levels of mRNA for inducible nitric oxide synthase and hemo oxygenase-1 were elevated, but to a greater extent in UTI (-/-) mice than in WT mice. Immunohistochemistry showed that the formations of 8-hydroxy-2'-deoxyguanosine and nitrotyrosine in the lung were more intense in UTI (-/-) mice than in WT mice after LPS challenge. These results indicate that endogenous UTI is protective against acute lung injury induced by bacterial endotoxin, at least partly, via the antioxidative properties.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed2004

Urinary trypsin inhibitor protects against systemic inflammation induced by lipopolysaccharide.

Urinary trypsin inhibitor (UTI), a serine protease inhibitor, has been widely used as a drug for patients with acute inflammatory disorders such as disseminated intravascular coagulation, shock, and pancreatitis in Japan. Recent studies have demonstrated that serine protease inhibitors may play an anti-inflammatory role beyond merely an inhibitory action on neutrophil elastase at the site of inflammation at least in vitro. To clarify the direct contributions of UTI to inflammatory condition in vivo, we analyzed its roles in experimental systemic inflammatory response induced by intraperitoneal administration of lipopolysaccharide (LPS) using UTI deficient (-/-) mice and corresponding wild-type (WT) mice. After LPS (1 mg/kg) challenge, UTI (-/-) mice revealed a significant elevation of plasma fibrinogen and fibrinogen/fibrin degradation products and a decrease in white blood cell counts compared with WT mice. LPS treatment induced more severe neutrophilic inflammation in the lung and the kidney obtained from UTI (-/-) mice than in those from WT mice, which was confirmed by histological examination. The protein levels of proinflammatory mediators, such as macrophage chemoattractant protein (MCP)-1 in the lungs, MCP-1 and keratinocyte chemoattractant (KC) in the kidneys, and interleukin-1beta, macrophage inflammatory protein-2, MCP-1, and KC in the liver, were significantly greater in UTI (-/-) mice than in WT mice after LPS challenge. Our results suggest that UTI protects against systemic inflammatory response and subsequent organ injury induced by bacterial endotoxin, at least partly through the inhibition of the enhanced expression of proinflammatory cytokines and chemokines.

Animals↗
PubMed2004

Reduced intestinal inflammation induced by dextran sodium sulfate in interleukin-6-deficient mice.

Interleukin-6 (IL-6) is a multifunctional cytokine secreted by various cells, and is involved in the acute phase response and the immune response through T and B cell activation. To further define the role of IL-6 in intestinal inflammation, we studied the effects of dextran sulfate sodium (DSS) administration in mice with targeted deletions of the IL-6 gene. Acute colitis was induced in female IL-6-/- and IL-6+/+ mice by giving 4.5% DSS orally in drinking water for 8 days. The colonic mucosal injury and inflammation was evaluated based on survival rate, body-weight changes, total colon length and histological findings. Colonic mRNA expression for tumor necrosis factor (TNF)-alpha, IL-6, IL-10 and inducible nitric oxide synthase (iNOS) was measured by RT-PCR. Colonic IL-6 mRNA levels of wild-type mice continued to increase throughout the study period. At each assessment, colonic injury was significantly attenuated in DSS-treated IL-6-/- mice compared with DSS-treated IL-6+/+ mice. Histological study also showed a reduced infiltration of inflammatory cells, especially neutrophils, and mucosal cell disruption in DSS-treated IL-6-/- mice compared with DSS-treated IL-6+/+ mice. In the colons of DSS-treated IL-6-/- mice, the expression of both TNF-alpha mRNA and iNOS mRNA was reduced on day 5. In contrast, IL-10 mRNA expression was enhanced compared with DSS-treated IL-6+/+ mice. In conclusion, DSS-induced inflammation appears to be significantly inhibited in IL-6-/- mice compared to wild-type mice. These data suggest that persistent and marked blockade of IL-6 bioactivity provides some beneficial effects on intestinal inflammation.

Animals↗