Urinary trypsin inhibitor protects against systemic inflammation induced by lipopolysaccharide

Urinary trypsin inhibitor as a therapeutic option for endotoxin-related inflammatory disorders

IMPORTANCE OF THE FIELD

Urinary trypsin inhibitor (UTI), a serine protease inhibitor, has been widely used as a drug for patients with inflammatory disorders such as pancreatitis, shock and disseminated intravascular coagulation (DIC). Previous in vitro studies have demonstrated that serine protease inhibitors may have anti-inflammatory properties at sites of inflammation. However, the therapeutic effects of UTI in vivo remain unclarified, as commercial UTI has been developed to act against humans, with the activity and selectivity toward the relevant animal UTI being less characterized.

AREAS COVERED IN THIS REVIEW

In this review, we introduce the roles of UTI in experimental endotoxin (lipopolysaccharide; LPS)-related inflammatory disorders using UTI-deficient (-/-) and corresponding wild-type mice.

WHAT THE READER WILL GAIN

Our experiments using genetic approach suggest that endogenous UTI can protect against the systemic inflammatory response and subsequent organ injury induced by LPS, at least partly, through the inhibition of pro-inflammatory cytokine and chemokine expression, which provide important in vivo evidence and understanding about a protective role of UTI in inflammatory conditions.

TAKE HOME MESSAGE

Using genetically targeted mice selectively lacking UTI, UTI has been evidenced to provide an attractive 'rescue' therapeutic option for endotoxin-related inflammatory disorders such as DIC, acute lung injury and acute liver injury.

Recombinant bovine pancreatic trypsin inhibitor protects the liver from carbon tetrachloride-induced acute injury in mice

OBJECTIVES

Toxicity caused by pharmacological and chemical substances, including carbon tetrachloride (CCl(4)), is a major pathological factor for liver injury. Therefore, strategies to prevent toxicity are needed for maintaining a healthy liver. This study was designed to determine whether recombinant bovine pancreatic trypsin inhibitor (rBPTI), a non-specific serine protease inhibitor, prevents CCl(4)-induced liver injury in mice.

METHODS

Mice were treated with CCl(4) in the presence or absence of co-treatment with rBPTI. Liver sections were prepared for histopathological assessment. Liver function was evaluated by detecting serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and liver index. Liver oxidative stress and inflammation were examined by detecting the liver malondialdehyde level and glutathione and superoxide dismutase activity, and serum tumour necrosis factor-alpha level, respectively.

KEY FINDINGS

CCl(4) induced hepatocyte necrosis, inflammatory cell infiltration and fatty degeneration, which were ameliorated by co-treatment with rBPTI in a concentration-dependent manner. Furthermore, rBPTI prevented CCl(4)-induced disruption of liver function. Importantly, rBPTI reduced CCl(4)-induced liver oxidative stress response and pro-inflammatory cytokine production.

CONCLUSIONS

These results indicated that rBPTI exerted a protective effect on CCl(4)-induced liver injury in mice. Thus, rBPTI may have potential application for prevention of liver injury induced by metabolism of drugs and toxic substances.

Cilostazol protects mice against endotoxin shock and attenuates LPS-induced cytokine expression in RAW 264.7 macrophages via MAPK inhibition and NF-kappaB inactivation: not involved in cAMP mechanisms

Cilostazol, a phosphodiesterase 3 inhibitor, is a platelet aggregation inhibitor and vasodilator that is useful for treating intermittent claudication. Experimental studies have shown that cilostazol has potent anti-inflammatory effects. In the present study, we examined the effect of cilostazol on lipopolysaccharide (LPS)-induced inflammatory cytokines in macrophages and endotoxin shock in mice. Our results indicate that cilostazol inhibits LPS-stimulated up-regulation of pro-inflammatory cytokines in a concentration-dependent manner without appreciable cytotoxicity in RAW 264.7 cells. Cilostazol did not enhance intracellular cyclic AMP (cAMP) levels. To further elucidate the mechanism responsible for the inhibition of production of pro-inflammatory mediators by cilostazol, we examined the effect of cilostazol on LPS-stimulated nuclear factor-kappaB (NF-kappaB) activation and phosphorylation of mitogen-activated protein kinases (MAPK). Our results clearly indicated that cilostazol treatment reduced on of MAPK phosphorylation and NF-kappaB activity, and that the inhibitory effect of cilostazol is independent of the cAMP pathway. In an animal model, cilostazol protected c57BL/6 mice from LPS-induced endotoxin shock, possibly through inhibition of the production of pro-inflammatory cytokines. In conclusion, cilostazol inhibits LPS-stimulated production of pro-inflammatory cytokines and protects mice from endotoxin shock, suggesting that cilostazol may be a novel therapeutic agent for the prevention of various inflammatory diseases.

Urinary trypsin inhibitor suppresses excessive generation of superoxide anion radical, systemic inflammation, oxidative stress, and endothelial injury in endotoxemic rats

OBJECTIVE AND DESIGN

The protective effects of ulinastatin, a human urinary trypsin inhibitor (UTI), against superoxide radical (O(2)(-*)) generation, systemic inflammation, lipid peroxidation, and endothelial injury were investigated in endotoxemic rats.

MATERIALS AND TREATMENT

Twenty-one Wistar rats were allocated to a control group, a UTI group, and a sham group. A bolus of lipopolysaccharide (LPS; 3 microg/g) was administered intravenously to the control group, a bolus of LPS and UTI (5 U/g) to the UTI group, and a bolus of saline to the sham group.

METHODS

The O(2)(-*) generated was measured as the current in the right atrium using an electrochemical O(2)(-*) sensor. Plasma nitrite, high mobility group box 1 (HMGB1), tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, malondialdehyde, and soluble intercellular adhesion molecule-1 (sICAM-1) were measured 360 min after LPS administration.

RESULTS

The O(2)(-*) current increased in the control group and was significantly attenuated in the UTI group after 55 min (P < 0.05 at 55-60 min, P < 0.01 at 65-360 min). Plasma nitrite, HMGB1, TNF-alpha, IL-6, malondialdehyde, and sICAM-1 were attenuated in the UTI group.

CONCLUSIONS

UTI suppressed excessive O(2)(-*) generation, systemic inflammation, lipid peroxidation, and endothelial injury in endotoxemic rats.

ONO 3403, a synthetic serine protease inhibitor, inhibits lipopolysaccharide-induced tumor necrosis factor-{alpha} and nitric oxide production and protects mice from lethal endotoxic shock

ONO 3403, a new synthetic serine protease inhibitor, is a derivative of camostat mesilate and has a higher protease-inhibitory activity. The effect of ONO 3403 on lipopolysaccharide (LPS)-induced tumor necrosis factor (TNF)-α and nitric oxide (NO) production in RAW 264.7 macrophage-like cells was examined. ONO 3403 significantly inhibited LPS-induced TNF-α production at a lower concentration than camostat mesilate. It also inhibited LPS-induced NO production. Their inhibition was responsible for the reduced mRNA expression of TNF-α and inducible NO synthase. In LPS-stimulated cells, ONO 3403 prevented the augmentation of MyD88 expression and inhibited the phosphorylation of IκB-α, stress-activated protein kinase (SAPK) and IRF-3, and the production of interferon-β. ONO 3403 abolished the elevation of the extracellular serine protease activity in response to LPS. Further, it reduced the circulating TNF-α level, hepatic injury and mortality in mice receiving an injection of D-galactosamine and LPS. ONO 3403 was suggested to inhibit LPS-induced inflammatory responses via inactivation of MyD88-dependent and independent pathways.

Urinary trypsin inhibitor protects against liver injury and coagulation pathway dysregulation induced by lipopolysaccharide/D-galactosamine in mice

Urinary trypsin inhibitor (UTI), a serine protease inhibitor, has been widely used for patients with inflammatory disorders including disseminated intravascular coagulation, shock, and pancreatitis in Japan. Our recent studies using UTI-null (-/-) mice have shown that UTI protects against systemic inflammatory responses and acute lung injury. However, the role of UTI in liver injury has not been elucidated. This study determined the contribution of UTI to liver injury and coagulatory disturbance induced by lipopolysaccharide and D-galactosamine (LPS/D-GalN) using UTI (-/-) and wild-type (WT) mice. LPS/D-GalN treatment caused severe liver injury characterized by neutrophilic inflammation, hemorrhagic change, necrosis, and apoptosis, which was more prominent in UTI (-/-) than in WT mice. In both genotypes of mice, LPS/D-GalN challenge caused elevations of aspartate amino-transferase and alanine amino-transferase, prolongation of the prothrombin and activated partial thromboplastin time, and decreases in fibrinogen and platelet counts, as compared with vehicle challenge. These changes, however, were significantly greater in UTI (-/-) than in WT mice. Circulatory levels of tumor necrosis factor (TNF)-alpha (P<0.05) and interferon (IFN)-gamma were also greater in UTI (-/-) than in WT mice after LPS/D-GalN challenge. These results suggest that UTI protects against severe liver injury and subsequent coagulatory disturbance induced by LPS/D-GalN, which was mediated, at least partly, through the suppression of TNF-alpha production along with its antiprotease activity.

Protective effects of urinary trypsin inhibitor on systemic inflammatory response induced by lipopolysaccharide

Urinary trypsin inhibitor (UTI), a serine protease inhibitor, has been widely used in Japan as a drug for patients with acute inflammatory disorders such as disseminated intravascular coagulation (DIC), shock, and pancreatitis. Recent in vitro studies have demonstrated that serine protease inhibitors may have anti-inflammatory properties beyond their inhibition of neutrophil elastase at the site of inflammation. However, the therapeutic effects of UTI in vivo remain unclear. In this review, we introduce the roles of UTI in the experimental systemic inflammatory response induced by both intraperitoneal and intratracheal administration of lipopolysaccharide using UTI deficient and wild-type mice. Our experiments suggest that UTI can protect against systemic inflammatory response and subsequent organ injury induced by bacterial endotoxin, at least partly, through the inhibition of proinflammatory cytokine and chemokine expression. UTI may therefore present an attractive “rescue” therapeutic option for systemic inflammatory response syndromes such as DIC, acute lung injury, and multiple organ dysfunction.

Risk factors of prognosis for chronic liver failure

AIM: To investigate independent risk factors of prognosis for chronic liver failure and to establish its prognostic model.

METHODS: Retrospective analysis was conducted on clinical aspects of 228 patients with liver failure receiving artificial liver treatment between May 2002 and March 2007 in Tianjin third central hospital. Data were analyzed using SPSS 13.0 statistic software. Quantitative data were analyzed using t test and rank test, and qualitative data were analyzed using Chi-square test, then Logistic regression analysis was used for selecting the independent risk factors affecting the prognosis. Based on independent risk factors from Logistic regression model, prognostic model for our patients with chronic liver failure was established.

RESULTS: Independent risk factors included Child-Pugh score, tyrosine, bilirubin separation ALT, liver cancer, indirect bilirubin, serum sodium and leukocyte. The mortality of patients with LOG model score higher than 9.5 was 72.18%, while the mortality of patients with LOG model score under 9.5 was 13.68%. There was significant difference between the two (P < 0.05). Based on LOG model score, 7-9 score was considered as early stage, 10-12 score as middle stage and 13-14 score as advanced stage. The mortality of three stages were 13.68%, 68.91%, and 100%, respectively, which showed significant differences among them (P < 0.05).

CONCLUSION: Child-Pugh score, tyrosine, bilirubin separation ALT, liver cancer, indirect bilirubin, serum sodium and leukocyte are independent risk factors affecting prognosis. LOG model established in our study has better predictability.

Intestinal alkaline phosphatase detoxifies lipopolysaccharide and prevents inflammation in zebrafish in response to the gut microbiota

Vertebrates harbor abundant lipopolysaccharide (LPS) in their gut microbiota. Alkaline phosphatases can dephosphorylate and detoxify the endotoxin component of LPS. Here, we show that expression of the zebrafish intestinal alkaline phosphatase (Iap), localized to the intestinal lumen brush border, is induced during establishment of the gut microbiota. Iap-deficient zebrafish are hypersensitive to LPS toxicity and exhibit the excessive intestinal neutrophil influx characteristic of wild-type zebrafish exposed to LPS. Both of these Iap mutant phenotypes are dependent on Myd88 and Tumor Necrosis Factor Receptor (Tnfr), proteins also involved in LPS sensitivity in mammals. When reared germ-free, the intestines of Iap-deficient zebrafish are devoid of neutrophils. Together, these findings demonstrate that the endogenous microbiota establish the normal homeostatic level of neutrophils in the zebrafish intestine through a process involving Iap, Myd88, and Tnfr. Thus, by preventing inflammatory responses, Iap plays a crucial role in promoting mucosal tolerance to resident gut bacteria.

Urinary trypsin inhibitor reduces inflammatory response in kidney induced by lipopolysaccharide

Human urinary trypsin inhibitor (UTI), a serine protease inhibitor, has been widely used in Japan as a drug for patients with acute inflammatory disorders such as septic shock and pancreatitis. Lipopolysaccharide (LPS) triggers the sepsis syndrome by activating monocytes to produce proinflammatory cytokines, including tumor necrosis factor alpha (TNFalpha), which potently stimulate the activation of neutrophils. The inhibitory mechanism of UTI on the systemic inflammatory response induced by the intraperitoneal injection of LPS in the kidney is unclear. This study was undertaken to examine the inhibitory effects of UTI on renal injury associated with the systemic inflammatory response induced by LPS stimulation, with emphasis on systemic TNFalpha and the activation of neutrophils in rat kidney. The systemic inflammatory response syndrome was induced by LPS treatment. Serum and renal TNFalpha, renal cytokine-induced neutrophil chemoattractant-1 (CINC-1) and myeloperoxidase (MPO) levels, as well as renal function after LPS stimulation, were evaluated. UTI (50,000 U/kg) inhibited LPS-induced increases in the serum and renal tissue levels of TNFalpha, as well as the renal tissue levels of CINC-1 and MPO after LPS stimulation. UTI (50,000 U/kg) also inhibited the production of serum TNFalpha associated with the systemic inflammatory response syndrome induced by LPS stimulation, thereby attenuating neutrophil infiltration into renal tissues and subsequent neutrophil-mediated renal injury. These findings may have important implications in understanding the biologic functions of UTI. UTI may prove useful in protecting against acute renal injury associated with a systemic inflammatory response.

Immunomodulation by n-3- versus n-6-rich lipid emulsions in murine acute lung injury--role of platelet-activating factor receptor

OBJECTIVE

Cytokines, platelet-activating factor (PAF), and eicosanoids control local and systemic inflammation. Conventional soybean oil-based lipid emulsions used for parenteral nutrition may aggravate the leukocyte inflammatory response or adhesion to the vessel wall. Fish oil-based lipid emulsions, in contrast, may exert an anti-inflammatory effect.

DESIGN

We investigated the impact of lipid emulsions on leukocyte invasion, protein leakage, and cytokines in two murine models of acute inflammation.

SETTING

Research laboratory of a university hospital.

SUBJECTS

Wild-type mice and PAF-receptor knockout mice.

INTERVENTIONS

Mice received an infusion of normal saline, fish oil- or soybean oil-based lipid emulsions before lipopolysaccharide challenge.

MEASUREMENTS AND MAIN RESULTS

Preinfusion with soybean oil resulted in increased leukocyte invasion, myeloperoxidase activity, and protein leakage and exaggerated release of tumor necrosis factor (TNF)-alpha as well as macrophage inflammatory protein (MIP)-2 into the alveolar space after intratracheal lipopolysaccharide challenge. In contrast, preinfusion with fish oil reduced leukocyte invasion, myeloperoxidase activity, protein leakage, and TNF-alpha as well as MIP-2 generation. Corresponding profiles were found in plasma following intraperitoneal lipopolysaccharide application: Soybean oil increased but fish oil decreased the TNF-alpha and MIP-2 formation. When PAF-receptor-deficient mice were challenged with lipopolysaccharide, leukocyte invasion, lung tissue myeloperoxidase, cytokine generation, and alveolar protein leakage corresponded to those observed in wild-type animals. Fish oil and soybean oil lost their diverging effects on leukocyte transmigration, myeloperoxidase activity, leakage response, and cytokine generation in these knockout mice. Similarly, the differential impact of both lipid emulsions on these lipopolysaccharide-provoked changes was suppressed after pretreating animals with a PAF-receptor antagonist.

CONCLUSIONS

Fish oil- vs. soybean oil-based lipid infusions exert anti- vs. proinflammatory effects in murine models of acute inflammation. The PAF/PAF-receptor-linked signaling appears to be a prerequisite for this differential profile.

Endogenous anti-inflammatory substances, inter-alpha-inhibitor and bikunin

There have been new developments in the elucidation of the biological functions of the inter-alpha-inhibitor (IalphaI) family. The anti-proteolytic activity of the IalphaI family originates from bikunin (also known as urinary trypsin inhibitor). Growing evidence indicates that bikunin is not just an anti-proteolytic agent, but can also be considered an anti-inflammatory agent that suppresses lipopolysaccharide (LPS)-induced cytokine synthesis. Bikunin functions to inhibit calcium influx and extracellular signal-regulated kinase (ERK) signaling via LPS receptors and/or as yet unidentified bikunin signaling receptors. By signaling via the LPS receptor, LPS increases calcium influx and yields phosphorylated ERK, which activates multiple transcription factors, such as nuclear factor kappaB (NF-kappaB) or early growth response-1 (Egr-1), which in turn promote cytokine expression. Deficits in the signaling cascades caused by free or cell-bound bikunin are predicted to down-regulate cytokine expression, render macrophages/neutrophils more inactive, and impair inflammatory processes. This brief review largely focuses on our current understanding of the apparent functions of bikunin, its ligands, the effector molecules with which it interacts, and its regulation.

The activation of neutrophil elastase-mediated fibrinolysis is not sufficient to overcome the fibrinolytic shutdown of disseminated intravascular coagulation associated with systemic inflammation

INTRODUCTION

We conducted a prospective study to test the hypothesis that the activation of neutrophil elastase-mediated fibrinolysis is insufficient to overcome the fibrinolytic shutdown of disseminated intravascular coagulation (DIC) in patients associated with systemic inflammation.

MATERIALS AND METHODS

We investigated 45 consecutive patients with systemic inflammatory response syndrome (SIRS) and sepsis, classified as 11 DIC and 34 non-DIC. Fibrin degradation products by neutrophil elastase (Elastase-XDP) and by plasmin (FDP), cross-linked fibrin degradation products (D-dimer), soluble fibrin, antithrombin, protein C, plasminogen activator inhibitor-1 (PAI-1), and urinary trypsin inhibitor (UTI) were measured within 24 h after the patients met either the SIRS or sepsis criteria (day 0), as well as on days 2 and 4.

RESULTS

In DIC patients, higher levels of soluble fibrin, PAI-1, and FDP and markedly lower levels of antithrombin and protein C were observed in comparison to those in non-DIC patients. DIC patients showed a significantly higher level of peak Elastase-XDP than non-DIC patients (25.7+/-5.9 vs. 16.3+/-2.6 microg/mL, respectively; p=0.0333). However, we could not find any substantial difference in the levels of Elastase-XDP, UTI, and D-dimer on each day during the study period between the two groups. Good correlations were observed between the levels of D-dimer and Elastase-XDP in both patients with and without DIC (r(s)=0.699 and r(s)=0.817, respectively), but the coefficients of determination in both groups showed low values and the slopes of the regression lines were less than 1.0. A multivariate logistic regression analysis showed the elevated peak Elastase-XDP levels to inversely correlate with death. On the other hand, the DIC patients showed a higher number of organ dysfunctions and a poorer prognosis than did the non-DIC patients.

CONCLUSIONS

The activation of the neutrophil elastase-mediated fibrinolytic pathway may be insufficient to overcome the fibrinolytic shutdown by PAI-1 and may in part explain the poor prognosis of DIC patients associated with systemic inflammation.

Local and systemic impacts of pleural oxygen exposure in thoracotomy

The pleural cavity is normally in a state of negative pressure and low oxygen tension. It is exposed to the atmosphere during thoracic surgery. However, no reports of pathophysiological investigation of the effects of pleural oxygen exposure involved in thoracotomy are available. In this study, the effects of pleural oxygen exposure on systemic and pleural inflammation were investigated. Male Wistar rats (9 weeks old) were placed on mechanical ventilation and underwent thoracotomy with lipopolysaccharide (LPS) administration, which simulates latent inflammatory condition. The pleural cavity was exposed to nitrogen (N(2) thoracotomy group), air (20% oxygen, air thoracotomy group), or 100% oxygen (O(2) thoracotomy group) under mechanical ventilation for 2 h. Animals were sacrificed 2 h or 8 h after LPS administration, and inflammatory indices (plasma tumor necrosis factor-alpha and interleukin-6, histology) were examined. For examination of inflammatory mediators, pleural effusion was added to cultured RAW264 cells, a murine macrophage cell line, and tumor necrosis factor-alpha levels in supernatant were measured. The capacity of pleural superoxide generation was investigated without LPS administration. Results showed increases in plasma interleukin-6 concentration and lung injury in the air and O(2) thoracotomy groups. Pleural oxygen exposure stimulated pleural superoxide generation, and increased pleural 4-hydroxy-2-nonenal and lung lipid peroxide concentrations. Tumor necrosis factor-alpha levels in cell culture supernatants were increased by the addition of pleural effusion from the air and O(2) thoracotomy groups. In conclusion, pleural oxygen exposure induced pleural oxidative injury and aggravated latent systemic inflammatory response.

Protective effects of ulinastatin on proliferation and cytokine release of splenocytes from rats with severe acute pancreatitis

AIM

To clarify the contributions of ulinastatin to cellular immune responses in vivo, we examined the functional alterations of splenocytes and quantitatively evaluated the effects of ulinastatin on the splenocyte function during experimental severe acute pancreatitis.

METHODS

Severe acute pancreatitis was induced in rats by retrograde injection of 3% sodium deoxycholate. Thirty minutes after induction of pancreatitis, the rats were randomly assigned to four groups, receiving either saline or 50,000 U/kg of ulinastatin, respectively. Splenocytes were obtained aseptically and stimulated with concanavalin A for 24 h. Then the proliferative activity of cultured splenocytes was measured by using an MTT cellular proliferation assay, and the cytokine concentrations in the culture supernatants were measured by enzyme-linked immunosorbent assays.

RESULTS

Upon stimulation, the release of interleukin-2, interleukin-10, and interferon-gamma was significantly decreased in the splenocytes from rats with pancreatitis as compared with those from sham operation and control groups. The splenocyte proliferation was also significantly suppressed in this group. In contrast, the proliferative as well as the cytokine-releasing capacities of the splenocytes from rats treated with ulinastatin were significantly increased as compared with those from rats with pancreatitis.

CONCLUSIONS

The deficiencies in proliferation and cytokine release in response to antigen stimulation demonstrated an anergic state of splenocytes during severe acute pancreatitis. Treatment with ulinastatin contributed to the recovery of the immune function by improving proliferative responses and cytokine release of splenocytes. These data suggest that a protease-modulating therapy may be an effective strategy for the treatment of immunosuppression induced by severe acute pancreatitis.

Biomarker and drug-target discovery using proteomics in a new rat model of sepsis-induced acute renal failure

Sepsis is one of the common causes of acute renal failure (ARF). The objective of this study was to identify new biomarkers and therapeutic targets. We present a new rat model of sepsis-induced ARF based on cecal ligation and puncture (CLP). We used this model to find urinary proteins which may be potential biomarkers and/or drug targets. Aged rats were treated with fluids and antibiotics after CLP. Urinary proteins from septic rats without ARF and urinary proteins from septic rats with ARF were compared by difference in-gel electrophoresis (DIGE). CLP surgery elevated interleukin (IL)-6 and IL-10 serum cytokines and blood nitrite compared with sham-operated rats. However, there was a range of serum creatinine values at 24 h (0.4-2.3 mg/dl) and only 24% developed ARF. Histology confirmed renal injury in these rats. Forty-nine percent of rats did not develop ARF. Rats without ARF also had less liver injury. The mortality rate at 24 h was 27% but was increased by housing the post-surgery rats in metabolic cages. Creatinine clearance and urine output 2-8 h after CLP was significantly reduced in rats which died within 24 h. Using DIGE we identified changes in a number of urinary proteins including albumin, brush-border enzymes (e.g., meprin-1-alpha) and serine protease inhibitors. The meprin-1-alpha inhibitor actinonin prevented ARF in aged mice. In summary, we describe a new rat model of sepsis-induced ARF which has a heterogeneous response similar to humans. This model allowed us to use DIGE to find changes in urinary proteins and this approach identified a potential biomarker and drug target - meprin-1-alpha.

Effects of Volatile Constituents of Rosemary Extract on Lung Inflammation Induced by Diesel Exhaust Particles

Epidemiological and experimental studies have implicated that diesel exhaust particles are involved in increases in morbidity and mortality from lung diseases. Recently, we have demonstrated that rosmarinic acid, a polyphenolic liquid component in perilla, inhibits lung inflammation induced by diesel exhaust particles in vivo, partly through its antioxidative property. We have also shown the antioxidative activities of volatile constituents of rosemary extract, the gaseous component in perilla, in vitro. The purpose of this study was to evaluate the effects of intratracheal administration of volatile rosemary extract on lung inflammation induced by diesel exhaust particles. ICR mice were treated with intratracheal administration of volatile rosemary extract before intratracheal exposure to diesel exhaust particles. Twenty-four hr later, diesel exhaust particles exposure elicited lung inflammation characterized by the infiltration of neutrophils and eosinophils, which was confirmed by cellular profile of bronchoalveolar lavage fluid and histological examination. Diesel exhaust particles enhanced the protein expressions of interleukin-1beta, macrophage inflammatory protein-1alpha, macrophage chemoattractant protein-1, and keratinocyte chemoattractant in the lung. Pretreatment with rosemary extract significantly inhibited the diesel exhaust particles-induced lung inflammation. Rosemary extract treatment also suppressed the diesel exhaust particles-enhanced lung expression of macrophage inflammatory protein-1alpha, macrophage chemoattractant protein-1, and keratinocyte chemoattractant. These results suggest that intratracheal administration of rosemary extract can prevent lung inflammation induced by diesel exhaust particles. The preventive effect is mediated, at least partly, through the inhibition of the enhanced lung expressions of macrophage inflammatory protein-1alpha, macrophage chemoattractant protein-1, and keratinocyte chemoattractants.

Neutrophil serine proteases: potential key regulators of cell signalling during inflammation

The serine proteases cathepsin G, human leucocyte elastase and proteinase 3 are major contents of neutrophils and are released at sites of inflammation. The common picture of their function was that they do not degrade extracellular proteins specifically. Recent studies provided evidence that these proteases are able to activate specifically pro-inflammatory cytokines and lead to the activation of different receptors. Neutrophil serine proteases might therefore be important regulators of inflammatory processes and are interesting targets for new therapeutic approaches against inflammatory disorders. This review summarizes the current knowledge on the regulation of cell signalling by neutrophil serine proteases.