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Biomedical subjects

Antonino Di Stefano

Publications and source records attributed to Antonino Di Stefano.

9 recordsLinked to original sources
PubMed2006

Hsp60 and Hsp10 down-regulation predicts bronchial epithelial carcinogenesis in smokers with chronic obstructive pulmonary disease.

BACKGROUND: The relation between smoking, chronic obstructive pulmonary disease (COPD), and lung cancer (LC) is an open field of investigation. A higher frequency of adenocarcinoma has been reported in patients with COPD. Heat shock proteins (Hsps) are implicated in tumoral cell growth and differentiation. The aim of the present study was to investigate the expression of Hsp60 and Hsp10 in bronchial biopsies from smokers with COPD and in 10 lung cancer patients and to evaluate the association between Hsps expression and carcinogenetic steps of LC. METHOD: An immunohistochemical study was performed for Hsp60 and Hsp10 in bronchial biopsies from 35 COPD (postbronchodilator forced expiratory volume in 1 second [FEV(1)]: 53 +/- 19% [mean +/- SD]) patients with a history of smoking (53 +/- 34 pack/years) and in 10 patients with adenocarcinoma or adenosquamous carcinoma (ASC). Immunopositivity was quantified in the bronchial epithelium and in specimens with ASC. RESULTS.: In smokers with COPD, 10 out of 35 patients had a normal bronchial epithelium (NBE), 12 showed basal cell hyperplasia (BCH), 5 squamous metaplasia (SM), and 8 dysplasia (Dy). It was found that 58 +/- 23% and 54 +/- 23% of NBE and 48 +/- 29% and 52 +/- 26% of BCH expressed Hsp60 and Hsp10, respectively; in contrast, only 3 +/- 3% and 3.6 +/- 2% of SM, 1.9 +/- 4% and 1.1 +/- 2% of Dy expressed Hsp60 and Hsp10, respectively. ASC specimens were negative for Hsps proteins. Interestingly, NBE also present at the edges of ASC specimens was negative for Hsps proteins. CONCLUSIONS: The loss of Hsp60 and Hsp10 immunopositivity is related to the development and progression of bronchial cancer in smokers with COPD.

Adenocarcinoma↗
PubMed2006

Reactive nitrogen species in the respiratory tract.

Endogenous Nitric Oxide (NO) plays a key role in the physiological regulation of airway functions. In response to various stimuli activated inflammatory cells (e.g., eosinophils and neutrophils) generate oxidants ("oxidative stress") which in conjunction with exaggerated enzymatic release of NO and augmented NO metabolites produce the formation of strong oxidizing reactive nitrogen species, such as peroxynitrite, in various airway diseases including asthma, chronic obstructive pulmonary diseases (COPD), cystic fibrosis and acute respiratory distress syndrome (ARDS). Reactive nitrogen species provoke amplification of inflammatory processes in the airways and lung parenchyma causing DNA damage, inhibition of mitochondrial respiration, protein dysfunction and cell damage ("nitrosative stress"). These effects alter respiratory homeostasis (such as bronchomotor tone and pulmonary surfactant activity) and the long-term persistence of "nitrosative stress" may contribute to the progressive deterioration of pulmonary functions leading to respiratory failure. Recent studies showing that protein nitration can be dynamic and reversible ("denitration mechanisms") open new horizons in the treatment of chronic respiratory diseases affected by the deleterious actions of "nitrosative stress".

Animals↗
PubMed2006

Molecular mechanisms of respiratory virus-induced asthma and COPD exacerbations and pneumonia.

Lower airways inflammation is a central feature of many lung diseases, including asthma, chronic obstructive pulmonary disease (COPD) and pneumonia. Although the specific characteristics of the inflammatory responses and the site of inflammation differ between one disease to another, they always involve recruitment and activation of inflammatory cells and changes in structural cells of the lung. Inflammatory responses are associated with an increased expression of a cascade of proteins including cytokines, chemokines, growth factors, enzymes, adhesion molecules and receptors. In most cases the increased expression of these proteins is the result of enhanced gene transcription: many of these genes are not expressed in normal cells under resting conditions but they are induced in the inflammatory process in a cell-specific manner. Transcription factors regulate the expression of many pro-inflammatory genes and play a key role in the pathogenesis of airway inflammation. Many studies have suggested a role for viral infections not only as a causative agent of pneumonia but also of asthma and COPD exacerbations. In this review we will provide an overview of the relationship between common respiratory viral infections and the molecular mechanisms involved in the activation of airway inflammation and on the regulation of transcription factors in these inflammatory respiratory diseases. The relative importance of each transcription factor will be certainly greatly clarified in the next few years with the growing availability of specific inhibitors capable of blocking activation of a specific transcription factor. Clearly this is an exciting new area of ongoing research with promising therapeutic potential.

Anti-Inflammatory Agents↗
PubMed2005

Nitrosative stress in the bronchial mucosa of severe chronic obstructive pulmonary disease.

BACKGROUND: Reactive nitrogen species, formed via the reaction of nitric oxide (NO) with superoxide anion and via (myelo)peroxidase-dependent oxidation of NO(2)(-), have potent proinflammatory and oxidizing actions. Reactive nitrogen species formation and nitrosative stress are potentially involved in chronic obstructive pulmonary disease (COPD) pathogenesis. OBJECTIVES: To investigate the expression of markers of nitrosative stress, including nitrotyrosine (NT), inducible NO synthase (iNOS), endothelial NO synthase (eNOS), myeloperoxidase (MPO), and xanthine oxidase (XO) in bronchial biopsies and bronchoalveolar lavage from patients with mild to severe stable COPD compared with control groups (smokers with normal lung function and nonsmokers). METHODS: The expression of NT, iNOS, eNOS, MPO and XO in the bronchial mucosa and bronchoalveolar lavage of patients was measured by using immunohistochemistry, Western blotting, and ELISA and correlated with the inflammatory cell profile. RESULTS: Patients with severe COPD in stable phase had higher numbers of NT(+) and MPO(+) cells in their bronchial submucosa compared with mild/moderate COPD, smokers with normal lung function, and nonsmokers (P < .01). iNOS(+) and eNOS(+) but not XO(+) cells were significantly increased in smokers with COPD or normal lung function compared with nonsmokers (P < .05 and P < .01, respectively). In patients with COPD, the number of MPO(+) cells was significantly correlated with the number of neutrophils (r = +0.61; P < .0025) in the bronchial submucosa. Furthermore, the number of NT(+) and MPO(+) cells was negatively correlated with postbronchodilator FEV(1). CONCLUSION: These data suggest that nitrosative stress, mainly mediated by MPO and neutrophilic inflammation, may contribute to the pathogenesis of severe COPD.

Aged↗
PubMed2002

Increased macrophage inflammatory protein-1alpha and macrophage inflammatory protein-1beta levels in bronchoalveolar lavage fluid of patients affected by different stages of pulmonary sarcoidosis.

Macrophage inflammatory protein (MIP)-1alpha and MIP-1beta are two CC chemokines that induce lymphocyte migration. MIP-1alpha preferentially mediates chemotaxis of CD8 rather than CD4 lymphocytes, whereas the reverse is true for MIP-1beta. Both these chemokines recognize CCR5 as a cellular receptor in T lymphocytes and alveolar macrophages. We measured the concentrations of MIP-1alpha and MIP-1beta in bronchoalveolar lavage fluid (BALF) of 30 subjects affected by different stages of pulmonary sarcoidosis and 18 healthy normal subjects. We also evaluated the expression of CCR5 in alveolar macrophages and lymphocytes. The BALF concentrations of MIP-1alpha were significantly increased only in Stage II and III sarcoidosis. On the contrary, the concentrations of MIP-1beta were significantly increased at all stages. A striking increase of CCR5 expression was observed in both lymphocytes and macrophages of all patients, along with a trend to decreased positivity from Stage I to III of the disease. The MIP-1beta concentrations correlated with the number of total (r = 0.65, p = 0.0001) and both CD4 (r = 0.64, p = 0.0001) and CD8 (r = 0.62, p = 0.0001) lymphocytes; on the contrary, the MIP-1alpha concentrations correlated only with CD8 lymphocytes (r = 0.45, p = 0.002). Finally, significant negative correlations were observed between the neutrophil percentage and CCR5 expression in alveolar macrophages (r = -0.53, p = 0.005) and lymphocytes (r = -0.43, p = 0.01). Our results help to explain the mechanism of CD4 and CD8 recruitment and the possible involvement of CC chemokines in the fibrotic progression of sarcoidosis.

Adult↗