Hiroyuki Nakamura

Senescence-associated secretory phenotype in a mouse model of bleomycin-induced lung injury

Bleomycin produces DNA damage, apoptosis and senescence, all of which play crucial roles in the development of pulmonary fibrosis. Recently, close attention has been paid to a DNA damage-induced phenotypic change (senescence-associated secretory phenotype; SASP) as a trigger for the secretion of various mediators which modify the processes of tissue injury, inflammation, repair and fibrosis. We characterized the SASP in a murine model of bleomycin-induced lung injury. Mice were intratracheally administered bleomycin or control saline, and the lungs were obtained on days 7, 14 and 21. The occurrence of DNA damage and the SASP in the lungs was examined by immunostaining. γH2AX immunostaining of the bleomycin-treated lungs revealed double-strand breaks (DSBs), largely within E-cadherin-positive, β4-integirn-positive alveolar epithelial cells. The DSBs were associated with phosphorylation of ATM/ATR, a central signal transducer mediating the DNA damage response, and upregulation of the cyclin-dependent kinase inhibitor p21(CIP1). The DSBs persisted for at least 21 days after the bleomycin exposure, although it began to wane after 7 days. A subpopulation of the γH2AX-positive, DNA-damaged cells exhibited the SASP, characterized by overexpression of IL-6, TNFα, MMP-2 and MMP-9, in association with the phosphorylation of IKKα/β and p38 MAPK. Persistent DNA damage and the SASP are induced in the process of bleomycin-induced lung injury and repair, suggesting that these events play an important role in the regulation of inflammation and tissue remodeling in bleomycin-induced pneumopathy.

Effects of acute exercise on lung antioxidant enzymes in young and old rats.

The lung could be the target organ to cellular damage, since it is directly exposed to high concentrations of oxygen. Acute exercise and age would be an added challenge to the lung, and therefore, we investigated alterations of major lung antioxidant enzymes (manganese-superoxide dismutase, Mn-SOD; copper-zinc-SOD, Cu-Zn-SOD; glutathione peroxidase, GPX; catalase, CAT) activities and mRNA expressions in young (4 months old) and old (26 months old) male Wistar rats with exercise. Thioredoxin reductase (TrxR) activity was also investigated. Mn-SOD and Cu-Zn-SOD increased with age, but age did not affect GPX, CAT, or TrxR activity. Acute exercise in young animals increased the activities of Mn-SOD, Cu-Zn-SOD, and CAT. In contrast, only Mn-SOD increased significantly in the old animals. The mRNA expressions of Mn-SOD, Cu-Zn-SOD and GPX were not altered with age, while CAT mRNA expression decreased with age. Acute exercise had no significant effect on any of the antioxidant enzyme mRNA expression. Moreover, reactive carbonyl derivative increased with age, but no significant changes were detected after acute exercise in either group. In summary, antioxidant enzymes responsible for the removal of hydrogen peroxide were unable to increase their enzyme activities in the old animals with exercise.

Undernutrition in Patients with COPD and Its Treatment

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory disorder of the lung and whole body caused mainly by tobacco smoking. Patients with advanced COPD are in a state of undernutrition, referred to as pulmonary cachexia; the exercise performance and quality of life (QOL) of these patients are deteriorated, the vital prognosis is unfavorable, and the medico-economic burden posed by poorly nourished COPD patients is high. The mainstays of COPD treatment are pharmacotherapy, mainly with bronchodilators, and non-pharmacotherapeutic approaches such as respiratory rehabilitation and nutrition counseling. Nutritional supplement therapy, consisting primarily of high calorie intake, has been demonstrated to be effective for maintaining and improving the muscle strength and exercise tolerance in poorly nourished COPD patients. The efficacy of intake of various nutrients, besides a high calorie intake, for amelioration of the disease state of COPD has also been reported. The roles of adipokines in the pathophysiology of COPD have begun to receive attention recently, and not only their regulatory effects on appetite and nutritional status, but also their influence on systemic inflammation have been increasingly clarified. We review the papers on COPD and nutrition and discuss the role of nutritional supplement therapy in the treatment of COPD.

Tumor debulking by radiofrequency ablation in hypertrophic pulmonary osteoarthropathy associated with pulmonary carcinoma

A 73-year-old male with stage IV lung adenocarcinoma presented with leg swelling and clubbing of the fingers on both hands upon physical examination, and bone scintigrams demonstrated marked accumulation of 99mTc-MDP in the long bones adjacent to the patellae. A diagnosis of hypertrophic pulmonary osteoarthropathy associated with primary lung cancer was made. Radiofrequency ablation (RFA) was utilized for cytoreduction, because the patient refused chemotherapy. One-month follow-up CT scans revealed low density of the ablated area associated with ablation necrosis. Cytoreduction by RFA rapidly alleviated the arthralgia and swelling, but not the clubbing of fingers. Follow-up bone scintigrams demonstrated a reduction in patellar uptake after RFA.

Tacrolimus-induced pulmonary injury in rheumatoid arthritis patients.

BACKGROUNDnTacrolimus (TAC) was approved in Japan in 2005 for rheumatoid arthritis (RA) patients having inadequate response to other disease-modifying anti-rheumatic drugs. As of May 2007, spontaneous reports identified twenty-seven cases of exacerbation or new development of interstitial pneumonia among RA patients given TAC in Japan.nnnOBJECTIVEnTo describe the clinical and radiological characteristics of TAC-induced pulmonary injury (TIPI).nnnPATIENTS AND METHODSnEleven RA patients diagnosed with de novo pulmonary injury or exacerbation of IP during treatment with TAC were identified. Clinical, radiological, and laboratory data of ten of these cases were retrospectively analyzed.nnnRESULTSnBaseline data for the ten patients were a mean age of 69.7 years; gender, 70% female; mean RA disease duration, 9.1 years; and pulmonary comorbidities, 90%. Six cases were classified as presumptive TAC-induced pulmonary injury (TIPI) and four as probable TIPI. Among the six presumptive cases, TIPI developed at an average of 84 days after initiation of treatment (n = 5) or four days after reinstitution of TAC (n = 1). Five cases were an exacerbation of pre-existing interstitial pneumonia and one was a de novo pulmonary injury. Radiological patterns of thoracic computed tomography (CT) scans of patients in the presumptive TIPI cases were hypersensitivity pneumonia like-pattern (n = 3), ground-glass opacity (n = 2), and organizing pneumonia-pattern (n = 1). All patients with presumptive TIPI were treated with high dosage glucocorticosteroids and one received concomitant immunosuppressants. Two of the six presumptive TIPI patients died.nnnCONCLUSIONnRheumatologists should be aware of this rare but potentially life-threatening adverse event in RA patients receiving TAC.

Prognosis in bronchogenic squamous cell carcinoma groups divided according to serum squamous cell carcinoma-related antigen and cytokeratin 19 fragment levels.

We examined differences in the 2-year survival rate in bronchogenic squamous cell carcinoma patients with normal serum levels of both cytokeratin 19 fragment (CYFRA 21-1) and squamous cell carcinoma-related antigen (SCC) (NL group, n=15), patients with only increased SCC levels (SCC+ group, n=14), patients with only increased CYFRA 21-1 levels (CYFRA+ group, n=14), and patients with elevated levels of both CYFRA 21-1 and SCC (EL group, n=65). The 2-year survival rates for the CYFRA+ and the EL group were lower than those for the SCC+ group and the NL group (0 and 12.9% vs. 66.7 and 85.6%, log rank: p<0.0001, Wilcoxon: p<0.0001). However, there were no differences between the rate for the SCC+ and the NL group and between that for the CYFRA+ and the EL group. Serum carcinoembryonic antigen (CEA) levels increased in the patients with the elevated CYFRA 21-1 levels. This results suggest that there may be some differences between squamous cell carcinoma patients with increased CYFRA 21-1 levels and those with normal levels and that it is CYFRA 21-1 levels, not SCC levels, that relate to the prognosis.

Systemic effects of acute cigarette smoke exposure in mice

Abstract Context: Cigarette smoke (CS) causes both pulmonary and extrapulmonary disorders. Objective: To determine the pulmonary and extrapulmonary effects of acute CS exposure in regard to inflammation, oxidative stress and DNA damage. Materials and methods: Mice were exposed to CS for 10 days and then their lungs, heart, liver, pancreas, kidneys, gastrocnemius muscle and subcutaneous (inguinal and flank) and visceral (retroperitoneum and periuterus) adipose tissues were excised. Bronchoalveolar lavage fluid samples were obtained for differential cell analysis. Inflammatory cell infiltration of the tissues was assessed by immunohistochemistry for Mac-3+ cells, F4/80+ cells and CD45+ cells. Oxidative stress was determined by immunohistochemistry for thymidine glycol (a marker of DNA peroxidation) and 4-hydroxy hexenal (a marker of lipid peroxidation), by enzyme-linked immunosorbent assay for protein carbonyls (a marker of protein peroxidation) and by measurements of enzyme activities of glutathione peroxidase, superoxide dismutase and catalase. DNA double-strand breaks were assessed by immunohistochemistry for γH2AX. Results: CS exposure-induced inflammatory cell infiltration, oxidative stress and DNA damage in the lung. Neither inflammatory cell infiltration nor DNA damage was observed in any extrapulmonary organs. However, oxidative stress was increased in the heart and inguinal adipose tissue. Discussions: Induction of inflammatory cell infiltration and DNA damage by acute CS exposure was confined to the lung. However, an increased oxidative burden occurred in the heart and some adipose tissue, as well as in the lung. Conclusions: Although extrapulmonary effects of CS are relatively modest compared with the pulmonary effects, some extrapulmonary organs are vulnerable to CS-induced oxidative stress.

The danger signal plus DNA damage two-hit hypothesis for chronic inflammation in COPD

Inflammation in chronic obstructive pulmonary disease (COPD) is thought to originate from the activation of innate immunity by a danger signal (first hit), although this mechanism does not readily explain why the inflammation becomes chronic. Here, we propose a two-hit hypothesis explaining why inflammation becomes chronic in patients with COPD. A more severe degree of inflammation exists in the lungs of patients who develop COPD than in the lungs of healthy smokers, and the large amounts of reactive oxygen species and reactive nitrogen species released from inflammatory cells are likely to induce DNA double-strand breaks (second hit) in the airways and pulmonary alveolar cells, causing apoptosis and cell senescence. The DNA damage response and senescence-associated secretory phenotype (SASP) are also likely to be activated, resulting in the production of pro-inflammatory cytokines. These pro-inflammatory cytokines further stimulate inflammatory cell infiltration, intensifying cell senescence and SASP through a positive-feedback mechanism. This vicious cycle, characterised by mutually reinforcing inflammation and DNA damage, may cause the inflammation in COPD patients to become chronic. Our hypothesis helps explain why COPD tends to occur in the elderly, why the inflammation worsens progressively, why inflammation continues even after smoking cessation, and why COPD is associated with lung cancer. A vicious cycle, involving mutually reinforcing inflammation and DNA damage, may cause chronic inflammation in COPD http://ow.ly/nYW4u

Chronological change of serum carcinoembryonic antigen (CEA) concentrations and pulmonary function data after cessation of smoking in subjects with smoking-associated CEA abnormality.

We evaluated changes in serum carcinoembryonic antigen (CEA), peripheral neutrophil concentrations, and ratio of the forced expiratory volume in 1 s to the forced vital capacity (FEV1%) values after cessation of smoking in subjects with smoking-associated CEA abnormality (>5.0 ng/ml) (n=119). In all 25 subjects who gave up smoking (ex-smokers), CEA concentrations 1 year after the cessation decreased within the reference range and neutrophil concentrations were lower than those while smoking. However, both concentrations after 3 years were still higher than those who have never smoked (non-smokers) (n=86). Average CEA and neutrophil concentrations in 94 subjects who continued to smoke (smokers) were stable. There was no difference between chronological changes of FEV1% over 3 years in ex-smokers and in smokers. However, FEV1% values for 3 years in ex-smokers were lower than those in non-smokers. These findings suggest that the ex-smokers who gave up smoking 3 years ago are still affected by past smoking.

Observational study on the efficacy and safety of erlotinib in patients with non-small cell lung cancer

To evaluate the efficacy and safety of erlotinib for non-small cell lung cancer (NSCLC), we performed a population-based observational study. The study involved 307 patients treated with erlotinib at 14 sites (17 departments) in Ibaraki (Japan) between December 2007 and December 2010. The tumor response and disease control rates were 11.1 and 46.3% in all patients, respectively. The median time to treatment failure and survival time were 1.6 months (95% confidence interval, 41–57 days) and 5.3 months (134–181 days) in all patients, respectively. Survival was significantly prolonged in EGFR mutation-positive patients compared with negative patients. EGFR mutation-negative patients who presented with a skin rash had significantly prolonged survival compared with those without a skin rash. The most common adverse event was skin disorder, followed by diarrhea. Although 45.6% of the patients in this study received erlotinib as a fourth-line or subsequent treatment, the results from this study were similar to those of clinical studies. We deduce that erlotinib is effective against NSCLC and is tolerated in clinical practice.