Hideaki Yamasawa

Cytokine-induced neutrophil chemoattractant in a rat model of lipopolysaccharide-induced acute lung injury.

To elucidate the role of major chemotactic factors, cytokine-induced neutrophil chemoattractant (CINC), leukotriene B4 (LTB4) and C5a in lipopolysaccharide (LPS)-induced acute lung injury in rat, we employed three reagents: anti-CINC-1 antibody, an LTB4 receptor antagonist (ONO-4057) and an anti-complementary agent (K-76COONa). Rats were divided into five groups: (1) control group; (2) LPS group, which received intratracheal instillation of LPS (100 μg/kg); (3) Anti-CINC group, which received intratracheal coinstillation of LPS with anti-CINC-1 antibody (1 mg/kg); (4) LTB4-Ra group, which received intravenous ONO-4057 (10 mg/kg) prior to intratracheal LPS; (5) Anti-C5a group, which received intravenous K-76COONa (100 mg/kg) prior to intratracheal LPS. The number of neutrophils in bronchoalveolar lavage (BAL) fluids 6 h after LPS instillation was significantly reduced in the Anti-CINC group, however, no reduction was found in either the LTB4-Ra group or Anti-C5a group. The levels of CINC-1, CINC-2α and CINC-3 in BAL fluids were significantly higher in the LPS group than in the saline-instilled control group. In vitro, the production of CINC-1 and CINC-3 from LPS-stimulated macrophages was significantly elevated compared to unstimulated macrophages 6 h later. The increase in CINC-2α production was markedly less than that of CINC-1 or CINC-3. These results indicate that CINCs, especially CINC-1 and CINC-3 play an important role in the recruitment of neutrophils to the lung in LPS-induced acute lung injury.

Concurrence of Sarcoidosis and Lung Cancer

Although sarcoidosis and lung cancer are both frequently encountered conditions, their simultaneous occurrence in the same patient is unusual. In this report, we describe 4 cases of their concurrence and discuss the possible pathogenic mechanisms of their concurrent appearance. In particular, in 2 of the cases, both diseases had coexisted for a long period (more than 6 and 4 years, respectively), showing a surprisingly slow growth of cancers. Although the chest computed tomography showed hilar and mediastinal lymphadenopathy, the histopathological findings of the excised lymph nodes of both cases revealed no metastasis. The causal relationship between sarcoidosis and lung cancer remains uncertain, but cases such as these may be helpful in elucidating its precise nature.

Physical activity in patients with idiopathic pulmonary fibrosis

Physical activity is an important parameter in patients with chronic obstructive pulmonary disease, but has not been studied in detail in patients with interstitial lung disease. This study aimed to evaluate physical activity in patients with idiopathic pulmonary fibrosis (IPF).

Drug-Induced Pneumonitis Associated with Imatinib Mesylate in a Patient with Idiopathic Pulmonary Fibrosis

A 74-year-old man with idiopathic pulmonary fibrosis (IPF) developed severe dyspnea on exertion after the readministration of imatinib mesylate for chronic myeloid leukemia. Chest X-ray and CT showed ground-glass opacities in both lungs in addition to preexisting honeycombing. Discontinuation of imatinib and methylprednisolone pulse therapy followed by administration of oral prednisolone resulted in improvement in both symptoms and radiographic findings. Imatinib-induced pneumonitis was diagnosed based on the clinical course and findings. Only five previous reports of imatinib-induced pneumonitis have been published in the literature, and this is the first case reported in a patient with IPF.

Clinical Significance of Interleukin 33 (IL-33) in Patients with Eosinophilic Pneumonia

BACKGROUND Interleukin 33 (IL-33) works as a functional mediator in allergic disease by enhancing the activity of eosinophils and inducing expression of T helper 2 (Th2)-associated cytokines. However, the role of IL-33 in pulmonary eosinophilia has not been elucidated. We investigated the levels of IL-33 in eosinophilic pneumonia (EP) together with associated cytokines, and discussed the clinical significance of IL-33 in EP. METHODS Sera and bronchoalveolar lavage fluid (BALF) were obtained from 16 patients with EP, including acute eosinophilic pneumonia (AEP) and chronic eosinophilic pneumonia (CEP). Twelve patients with acute respiratory distress syndrome (ARDS) were also included for comparison. The concentration of IL-33 and Th2 cytokines (IL-4, IL-5, IL-13) were measured by enzyme-linked immunosorbent assay (ELISA). RESULTS The concentration of serum IL-33 was significantly higher in patients with AEP than in CEP. In CEP, only patients with atopic factors showed mild increase of serum IL-33. The concentration of BALF IL-33 was also significantly elevated in AEP, however, it remained quite low in CEP. Among Th2 cytokines, IL-5 was significantly increased in both serum and BALF in AEP, and the level of IL-5 was positively correlated with that of IL-33. ARDS showed no increase of serum and BALF IL-33. CONCLUSIONS The remarkable increase of BALF IL-33 in AEP indicated the local production of IL-33 in lungs. IL-33 is considered to be a local key molecule for triggering pulmonary eosinophilia, together with IL-5. BALF IL-33 appears to be a useful marker for discriminating AEP from CEP and ARDS.

Preventive effects of edaravone, a free radical scavenger, on lipopolysaccharide‐induced lung injury in mice

Background and objective:  Reactive oxygen species (ROS) play an important role in the pathogenesis of acute lung injury (ALI) and pulmonary fibrosis. It was hypothesized that edaravone, a free radical scavenger, would be able to attenuate LPS‐induced lung injury in mice by decreasing oxidative stress.

NLRP3 Protein Deficiency Exacerbates Hyperoxia-induced Lethality through Stat3 Protein Signaling Independent of Interleukin-1β

Background: The role of NLRP3 inflammasomes in hyperoxic acute lung injury (HALI) remains unclear. Results: NLRP3 deficiency exacerbated lethality and diminished Stat3 activation caused by inflammatory cells in a murine HALI model. Conclusion: NLRP3 regulates Stat3 activation by affecting inflammatory cell infiltration independent of IL-1β. Significance: These findings demonstrate the novel role of NLRP3 in Stat3-mediated protective effects against HALI. Supplemental oxygen inhalation is frequently used to treat severe respiratory failure; however, prolonged exposure to hyperoxia causes hyperoxic acute lung injury (HALI), which induces acute respiratory distress syndrome and leads to high mortality rates. Recent investigations suggest the possible role of NLRP3 inflammasomes, which regulate IL-1β production and lead to inflammatory responses, in the pathophysiology of HALI; however, their role is not fully understood. In this study, we investigated the role of NLRP3 inflammasomes in mice with HALI. Under hyperoxic conditions, NLRP3−/− mice died at a higher rate compared with wild-type and IL-1β−/− mice, and there was no difference in IL-1β production in their lungs. Under hyperoxic conditions, the lungs of NLRP3−/− mice exhibited reduced inflammatory responses, such as inflammatory cell infiltration and cytokine expression, as well as increased and decreased expression of MMP-9 and Bcl-2, respectively. NLRP3−/− mice exhibited diminished expression and activation of Stat3, which regulates MMP-9 and Bcl-2, in addition to increased numbers of apoptotic alveolar epithelial cells. In vitro experiments revealed that alveolar macrophages and neutrophils promoted Stat3 activation in alveolar epithelial cells. Furthermore, NLRP3 deficiency impaired the migration of neutrophils and chemokine expression by macrophages. These findings demonstrate that NLRP3 regulates Stat3 signaling in alveolar epithelial cells by affecting macrophage and neutrophil function independent of IL-1β production and contributes to the pathophysiology of HALI.

Effects of edaravone, a free-radical scavenger, on bleomycin-induced lung injury in mice

Reactive oxygen species play an important role in the pathogenesis of acute lung injury and pulmonary fibrosis. The present authors hypothesise that edaravone, a free-radical scavenger, is able to attenuate bleomycin (BLM)-induced lung injury in mice by decreasing oxidative stress. Lung injury was induced in female ICR mice by intratracheal instillation of 5 mg·kg−1 of BLM. Edaravone (300 mg·kg−1) was administered by intraperitoneal administration 1 h before BLM challenge. Edaravone significantly improved the survival rate of mice treated with BLM from 25 to 90%, reduced the number of total cells and neutrophils in bronchoalveolar lavage fluid (BALF) on day 7, and attenuated the concentrations of lipid hydroperoxide in BALF and serum on day 2. The fibrotic change in the lung on day 28 was ameliorated by edaravone, as evaluated by histological examination and measurement of hydroxyproline contents. In addition, edaravone significantly increased the prostaglandin E2 concentration in BALF on day 2. In summary, edaravone was shown to inhibit lung injury and fibrosis via the repression of lipid hydroperoxide production and the elevation of prostaglandin E2 production in the present experimental murine system.

Preventive Effect of Hochu-ekki-to on Lipopolysaccharide-Induced Acute Lung Injury in BALB/c Mice

This study was designed to investigate the effect of Hochu-ekki-to (TJ-41), a Japanese herbal medicine, on the development of lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice. ALI was induced in female BALB/c mice by the intranasal administration of 0.1 mg/kg LPS. The mice were divided into a group receiving normal feed and another group receiving feed mixed with TJ-41 at a dose of 1 g/kg/day for 8 weeks before LPS challenge. In the bronchoalveolar lavage fluid, the preadministration of TJ-41 caused significant reduction in the absolute number of total cells, neutrophils, and macrophages. The preadministration of TJ-41 significantly inhibited increases in the serum level of keratinocyte chemoattractant (KC), which is a murine chemotaxin for neutrophils that corresponds to human interleukin-8, with respect to its concentration at 24 h after LPS challenge. Furthermore, the histopathologic findings indicated that alveolitis with leukocyte infiltration in the alveolar space was less severe in the TJ-41-treated mice than in the control mice. These findings indicated that the preadministration of TJ-41 could show an inhibitory effect on ALI in this experimental murine system associated with the suppression of chemokine production.

Preventive effect of hochu‐ekki‐to, a Japanese herbal medicine, on bleomycin‐induced lung injury in mice

Objective:  Pulmonary fibrosis is thought to be closely associated with the T‐helper type‐2 (Th2) immune response. Recent studies have shown that hochu‐ekki‐to (TJ‐41), a Japanese herbal medicine, may correct the Th1/Th2 imbalance skewed to Th2. The present study was designed to investigate the preventive effect of TJ‐41 on the development of bleomycin (BLM)‐induced lung injury in mice.