, is a dietary polyphenol that has been reported to possess antiinflammatory and antioxidant properties. The effect of curcumin against the development of pulmonary emphysema in animal models is unknown. The aim of this study was to determine whether curcumin is able to attenuate the development of pulmonary emphysema in mice. Nine-week-old male C57BL/6J mice were treated with intratracheal porcine pancreatic elastase (PPE) or exposed to mainstream cigarette smoke (CS) (60 min/day for 10 consecutive days or 5 days/wk for 12 wk) to induce pulmonary inflammation and emphysema. Curcumin (100 mg/kg) or vehicle was administrated daily by oral gavage 1 h and 24 h before intratracheal PPE treatment and daily thereafter throughout a 21-day period in PPE-exposed mice and 1 h before each CS exposure in CS-exposed mice. As a result, curcumin treatment significantly inhibited PPE-induced increase of neutrophils in bronchoalveolar lavage fluid at 6 h and on day 1 after PPE administration, with an increase in antioxidant gene expression at 6 h and significantly attenuated PPE-induced air space enlargement on day 21. It was also found that curcumin treatment significantly inhibited CS-induced increase of neutrophils and macrophages in bronchoalveolar lavage fluid after 10 consecutive days of CS exposure and significantly attenuated CS-induced air space enlargement after 12 wk of CS exposure. In conclusion, oral curcumin administration attenuated PPE-and CS-induced pulmonary inflammation and emphysema in mice.anti-inflammation; antioxidant; chronic obstructive pulmonary disease; polyphenol CHRONIC OBSTRUCTIVE PULMONARY disease (COPD) is characterized by airflow limitation that is not fully reversible; pulmonary emphysema is an important phenotype of COPD (33). COPD is a major public health problem that is the fifth leading cause of death worldwide, and its prevalence is expected to increase in the next few decades (34). Although the molecular and cellular mechanisms that are responsible for the development of COPD are not fully understood, chronic inflammation and oxidative stress in the lungs are believed to be key components of the pathogenesis of COPD and/or emphysema (38). Because there is no current effective drug therapy that prevents the progression of airflow limitation and/or emphysema, new anti-inflammatory and antioxidant therapeutic strategies are needed.We and others recently reported that NF-E2-related factor 2 (Nrf2), a key antioxidant transcriptional factor, and some Nrf2 target antioxidant enzymes were decreased in the lungs of patients with COPD and/or emphysema (15, 25), and especially in macrophages (50). It has been also reported that Nrf2-deficient mice are highly susceptible to oxidative stress and reactive electrophiles; severe emphysema develops when the mice are exposed to cigarette smoke (CS) or elastase (16,17,39). We also found (1) that immortalized murine Clara cells (C22) with depleted Nrf2 showed a decrease in the expression of several antioxidant genes and were much more susceptible to CS-induce...
Background: Although airflow limitation improved by inhaled anticholinergic drugs varies among individuals with chronic obstructive pulmonary disease (COPD), the relationship between actual bronchodilation and improved pulmonary function and where in the lung such bronchodilation occurs remains unknown. A study was undertaken to determine the relationship between improved pulmonary function and changes in airway calibre at various sites in the airways in response to inhaled anticholinergic agents in patients with COPD using three-dimensional computed tomography (CT). Methods: CT scans were performed at deep inspiration and detailed pulmonary function tests before and 1 week after daily inhalations of tiotropium bromide in 15 patients with clinically stable COPD. The airway luminal area was examined at the third (segmental) to the sixth generations of eight bronchi in the right lung. Results: Bronchodilation was demonstrated by an overall average increase of 39% in the inner luminal area, and the mean (SE) forced expiratory volume in 1 s (FEV 1 ) increased from 1.23 (0.11) l to 1.47 (0.13) l. The magnitude of bronchodilation was closely correlated with improved pulmonary function, particularly with that of FEV 1 (r = 0.843, p,0.001). Such correlations were significant at the fourth to the sixth generation but not at the third generation of bronchi, and the slope of the regression lines became steeper from the third to the sixth generation. Conclusions: Inhaled anticholinergic agents induce overall bronchodilation which is in proportion to improvements in FEV 1 in patients with COPD. Bronchodilation at the distal rather than the proximal airways is the determinant of functional improvement.Chronic obstructive pulmonary disease (COPD) is characterised by progressive airflow limitation that is not fully reversible. It is caused by a mixture of abnormal inflammatory responses in the small airways and parenchymal destruction of the lungs, the relative contributions of which vary among individuals.
BackgroundCatalase is preferentially expressed in bronchiolar and alveolar epithelial cells, and acts as an endogenous antioxidant enzyme in normal lungs. We thus postulated epithelial damage would be associated with a functional deficiency of catalase during the development of lung fibrosis.MethodsThe present study evaluates the expression of catalase mRNA and protein in human interstitial pneumonias and in mouse bleomycin-induced lung injury. We examined the degree of bleomycin-induced inflammation and fibrosis in the mice with lowered catalase activity.ResultsIn humans, catalase was decreased at the levels of activity, protein content and mRNA expression in fibrotic lungs (n = 12) compared to control lungs (n = 10). Immunohistochemistry revealed a decrease in catalase in bronchiolar epithelium and abnormal re-epithelialization in fibrotic areas. In C57BL/6J mice, catalase activity was suppressed along with downregulation of catalase mRNA in whole lung homogenates after bleomycin administration. In acatalasemic mice, neutrophilic inflammation was prolonged until 14 days, and there was a higher degree of lung fibrosis in association with a higher level of transforming growth factor-β expression and total collagen content following bleomycin treatment compared to wild-type mice.ConclusionsTaken together, these findings demonstrate diminished catalase expression and activity in human pulmonary fibrosis and suggest the protective role of catalase against bleomycin-induced inflammation and subsequent fibrosis.
Bronchiolization is a key process in fibrosing lung in which the proliferative status of bronchiolar epithelium changes, leading to abnormal epithelial morphology. Within the context that caveolin-1 acts to suppress epithelial proliferation, we postulated that stimulating epithelial injury would lead to caveolin-1 downregulation and encourage proliferation. The present study evaluates the expression of caveolin-1, especially in bronchiolization, in C57BL/6J mice with bleomycin-induced lung fibrosis and in various types of re-epithelialization in human interstitial pneumonias (IPs). Immunohistochemically, levels of caveolin-1 decreased in the bronchiolar epithelium of mice treated with bleomycin. Levels of caveolin-1 mRNA in the whole lung were decreased at 7 and 14 days. Caveolin-1 mRNA was also decreased in laser-capture microdissection- retrieved bronchiolar epithelial cells at 7 days. Among patients with 12 IPs, including four usual IPs (UIPs) and eight nonspecific IPs (NSIPs), whole lung caveolin-1 was significantly decreased compared with 12 controls at both mRNA and protein levels. By scoring immunointensity, caveolin-1 was significantly reduced in bronchiolization and squamous metaplasia as well as in bronchiolar epithelium in 23 IPs (12 UIPs and 11 NSIPs) compared with bronchiolar epithelium from seven controls. These data suggested that loss of caveolin-1 is associated with abnormal re-epithelialization in lung fibrosis.
Pulmonary lymphangioleiomyomatosis (LAM) is characterized by the proliferation of abnormal smooth muscle cells (LAM cells) and destruction of alveolar structure. Immunohistochemical studies suggest that excess matrix metalloproteinases (MMPs) synthesized by LAM cells function in the proteolytic mechanisms of this disease. We postulated MMP levels in the blood are elevated in LAM patients. Serum samples were collected from 36 LAM patients and 25 controls, and gelatinolytic activities were semi-quantified by gelatin zymography. The reliability of serum data for MMP-9 was confirmed by the measurement of MMP-9 concentration in plasma by enzyme-linked immunosorbent assay as well as by gelatin zymography. Serum levels of MMP-9 (0.7+/-0.1 AU), but not MMP-2, were significantly elevated in LAM patients compared with controls (0.1+/-0 AU). Plasma and serum levels of MMP-9 significantly correlated. These results suggest the involvement of MMP-9 in LAM.
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