Shunji Tajima

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.

Preventive effect of irbesartan on bleomycin-induced lung injury in mice

BACKGROUND Idiopathic pulmonary fibrosis is a specific form of chronic fibrosing interstitial pneumonia that is limited to the lung. Angiotensin receptor blockers (ARBs) and peroxisome proliferator-activated receptor (PPAR) γ ligands have anti-inflammatory and anti-fibrotic effects. We investigated the effects of irbesartan-an ARB with PPAR γ activity-on the development of bleomycin-induced pulmonary fibrosis in mice. METHODS Lung injury was induced in imprinting control region (ICR) mice by intratracheal instillation of 2mg/kg of bleomycin. The treatment group orally received 20mg/kg of irbesartan for 5 consecutive days before instillation. The mice were sacrificed and were evaluated 14 days after bleomycin instillation. RESULTS Irbesartan reduced the fluid content and hydroxyproline level in the lung and improved the pathological findings as indicated by the Ashcroft score. Total cell counts, the numbers of macrophages, neutrophils, and lymphocytes, and the levels of transforming growth factor (TGF) β1 and monocyte chemotactic protein (MCP) 1 in the bronchoalveolar lavage fluid (BALF) were decreased. Treatment with a PPARγ antagonist GW9662 reversed some of the effects of irbesartan. CONCLUSIONS The results of this study indicated that irbesartan attenuated the development of bleomycin-induced pulmonary fibrosis in mice by decreasing TGF-β1 and MCP-1 via blocking of ATI, by binding to CCR2b, and by PPARγ-mediated inhibition of inflammation.

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.

Intrathoracic Sporadic Desmoid Tumor with the Beta-Catenin Gene Mutation in Exon 3 and Activated Cyclin D1

We report a case of intrathoracic desmoid tumor without familial adenomatous polyposis and demonstrate beta-catenin mutation of exon 3. A 15-year-old male presented with a desmoid tumor after having sustained an assault. In an examination for a mutation of the beta-catenin gene, an activating mutation from ACC (Thr) to GCC (Ala) at codon 41 was found. Immunohistochemical staining showed that accumulated beta-catenin protein was predominantly localized in the nuclei of desmoid cells, and cyclin D1 protein was also overexpressed. These findings might suggest that an activating mutation of the beta-catenin gene affected regulation of the cyclin D1 gene, resulting in the generation of intrathoracic sporadic desmoid tumor, which arose at the site of posttraumatic injury.

Dermatomyositis with hemorrhagic myositis

A 64-year-old Japanese female, diagnosed as dermatomyositis with acute interstitial pneumonia, complained of acute abdominal pain. Computed tomography of the abdomen showed hematoma in the right retroperitoneum and left rectus-sheath. Angiogram showed multiple small aneurysms on left iliolumbar artery and a horizontal linear flush, suggesting active bleeding foci in the muscles. Although arterial embolization therapy was effective for hemostatic treatment, she died of thrombotic thrombocytopenic purpura and multiple organ failure without respiratory insufficiency. Other causes of microaneurysm, such as systemic vasculitides or infectious diseases, were excluded. We considered that this is the first case report of dermatomyositis with hemorrhagic myositis associated with small aneurysms.

Effects of IS-741, a Synthetic Anti-Inflammatory Agent, on Bleomycin-Induced Lung Injury in Mice

Bleomycin (BLM)-induced lung injury consists of excessive inflammatory cell infiltration and fibrosis. IS-741 has been reported to be an anti-inflammatory drug through an inhibitory action on cell adhesion. In this study we investigated whether IS-741 could inhibit the progression of pulmonary fibrosis through inflammatory cell infiltration. Lung injury was induced in female C57BL/6 mice by intratracheal instillation of BLM. IS-741 was administered daily intraperitoneally. The hydroxyproline content and fluid content in the lung on Day 28 were significantly lower in the IS-741-treated mice. The histological degree of lung injury or fibrosis was reduced in IS-741-treated mice. Administration of IS-741 caused significant reduction in the absolute number of total cells, monocyte chemoattractant protein (MCP)-1, and cysteinyl leukotriene (cysLTs) levels in bronchoalveolar lavage fluid on Day 7. Furthermore, the hydroxyproline content was significantly lower in IS-741-treated mice even though IS-741 was started on Day 14 after BLM instillation. Treatment with IS-741 had an inhibitory effect on BLM-induced lung injury and fibrosis via the repression of MCP-1 or cysLTs in this murine experimental model.