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Biomedical subjects

R Gagliardo

Publications and source records attributed to R Gagliardo.

18 recordsLinked to original sources

Biochemical interaction between effects of beclomethasone dipropionate and salbutamol or formoterol in sputum cells from mild to moderate asthmatics.

BACKGROUND: Several in vitro studies demonstrate that corticosteroids and long-acting beta(2) agonists may have a complementary and synergistic mode of action on the inflammatory processes in asthma. METHODS: Sputum was induced in 20 mild to moderate asthmatic patients and the induced sputum cells (ISC) were cultured with beclomethasone dipropionate (BDP) 10(-7) M, salbutamol 10(-8) M and formoterol 10(-8) M either alone or in combination, BDP plus salbutamol and BDP plus formoterol, for 24 h. We measured the levels of growth macrophages-colony stimulating factor (GM-CSF), released on activation normal T cells expressed and activated (RANTES) and interleukin-8 (IL-8), in the supernatant of stimulated cells by ELISA. Furthermore, we assessed nuclear translocation of glucocorticoid receptor (GR) and the expression of beta(2) receptor in ISC by immunofluorescence and RT-PCR, respectively. RESULTS: The release of GM-CSF, RANTES and IL-8 in ISC was significantly reduced by BDP plus salbutamol or formoterol as compared with either drug alone (P < 0.0001). beta(2) receptor expression was increased after 30 min of incubation with BDP and continued to increase over a time period of 4 h (P < 0.0001). Furthermore after 30 min of incubation, nuclear translocation of GR was greater with BDP plus salbutamol or formoterol than with any of the drugs alone (P < 0.0001). CONCLUSION: The present ex vivo study demonstrates a complementary mode of action between BDP and salbutamol or formoterol leading to an enhanced anti-inflammatory activity.

Adult↗

In vitro effects of flunisolide on MMP-9, TIMP-1, fibronectin, TGF-beta1 release and apoptosis in sputum cells freshly isolated from mild to moderate asthmatics.

BACKGROUND: Corticosteroids play an important role in inflammation and remodelling of airways and are considered an important therapeutic target in asthma. Inflammation in asthma is characterized by a dysregulation of eosinophil apoptosis and of markers of airways remodelling. We evaluated the ability of flunisolide to inhibit in vitro the release of metalloproteinases-9 (MMP-9), tissue inhibitor metalloproteinases-1 (TIMP-1), transforming growth factor (TGF-beta) and fibronectin by sputum cells (SC) as well as to induce sputum eosinophil apoptosis. METHODS: The SC, isolated from induced sputum samples of 12 mild-to-moderate asthmatics, were cultured for 24 h in the presence or absence of flunisolide (1, 10 and 100 microM). The release of mediators was assessed by enzyme-linked immunosorbent assay (ELISA) whereas apoptosis was studied by TUNEL technique. RESULTS: Flunisolide (10 microM) significantly reduced MMP-9 and TIMP-1 (P = 0.0011 and P < 0.0001 respectively) and increased MMP-9/TIMP-1 molar ratio (P = 0.004). In addition, flunisolide decreased TGF-beta and fibronectin release by SC (P = 0.006; and P < 0.0001 respectively) and increased eosinophil apoptosis (P < 0.001). CONCLUSIONS: These results demonstrate that flunisolide may play an important role in the inhibition of airway inflammation and remodelling, by promoting the resolution of eosinophilic inflammation and by inhibiting the release of MMP-9, TIMP-1, TGF-beta and fibronectin.

Adult↗

Airway remodeling in the pathogenesis of asthma.

Asthma is characterized by a chronic inflammatory process of the airways followed by healing, the end result of which is an altered structure referred to as airway remodeling. Although the mechanisms responsible for such structural alterations appear to be heterogeneous, it is likely that abnormal airway cell dedifferentiation, migration, and redifferentiation, together with changes in connective tissue deposition, contribute to the altered restitution of airway structure and function. This altered restitution is often seen as fibrosis and increased smooth muscle, mucus gland mass, and vessel area. As a consequence of these structural changes, the airway wall in asthma is usually characterized by increased thickness and markedly and permanently reduced airway caliber. These features may result in increased airflow resistance, particularly when there is bronchial contraction and bronchial hyperresponsiveness. The effect on airflow is compounded by increased mucus secretion and inflammatory exudate, which not only block the airway passages but also cause increased surface tension favoring airway closure.

Airway Obstruction↗

Proliferation and activation of bronchial epithelial cells in corticosteroid-dependent asthma.

BACKGROUND: Structural and functional characteristics of bronchial epithelial cells in corticosteroid-dependent asthma are unknown. OBJECTIVE: In bronchial biopsy specimens from 16 control, 9 untreated asthmatic, 9 inhaled corticosteroid-treated asthmatic, and 19 corticosteroid-dependent asthmatic subjects, we evaluated epithelium morphology and patterns of cell apoptosis, proliferation, and activation. METHODS: We used the terminal deoxynucleotidyl-mediated dUTP nick end labeling (TUNEL) technique to study apoptosis. Immunohistochemistry was used to evaluate the expression of molecules related to apoptosis (such as Bcl-2 and P53), cell proliferation (PCNA), and cell activation (NFkappaB and CD40/CD40-L). RESULTS: Epithelium thickness was higher in corticosteroid-dependent asthmatic and control subjects than in inhaled corticosteroid-treated and untreated asthmatic subjects (P < .0001 and P <.0003). Very few TUNEL-positive epithelial cells were found in the 4 groups. Bcl-2 expression was higher in all groups of asthmatic subjects than in controls (P < .001). In corticosteroid-dependent asthmatic subjects, PCNA, NFkappaB, and CD40-L expression was higher than in inhaled corticosteroid-treated asthmatic (P < .001), untreated asthmatic (P <.001 and P < .04), and control (P < .01) subjects. CD40 expression was greater in corticosteroid-dependent asthmatic and untreated asthmatic subjects than in inhaled corticosteroid-treated asthmatic subjects (P < .0001 and P < .0006) and controls (P < .02 and P < .03). In corticosteroid-dependent asthma, PCNA expression was correlated with the epithelium thickness (P < .007). CONCLUSION: This study shows that in bronchial epithelial cells of corticosteroid-dependent asthma, markers of cell survival and proliferation are coexpressed with markers of cell activation, suggesting that in this disease epithelium repair is associated with a persistent activation state of epithelial cells.

Administration, Inhalation↗

Airway remodelling in the pathogenesis of asthma.

The inflammatory and remodelling processes that underlie asthma result from a highly complex interaction between various cell types. Apart from inflammatory cells, such as eosinophils, activated T cells, mast cells and macrophages, structural tissue cells such as epithelial cells, fibroblasts and smooth muscle cells can also play an important effector role through the release of a variety of mediators, cytokines and chemokines. This results in an acute inflammatory response that is characterized by vascular leakage, mucus hypersecretion, epithelial shedding and widespread airway narrowing. At the same time, through the release of mediators, cytokines, chemokines and growth factors, epithelial and mesenchymal cells cause persistence of the inflammatory infiltrate and induce structural changes in the airway wall, such as increased thickness of the basement membrane, increased collagen deposition, changes in bronchial microcirculation, and smooth muscle hypertrophy and hyperplasia. The end result of airway inflammation and remodelling is an increased thickness of the airway wall, leading to a reduced baseline airway calibre and exaggerated airway narrowing.

Animals↗

[Role of glucocorticosteroid receptors in bronchial asthma].

Glucocorticoids (GC) represent the cornerstone anti-inflammatory treatment of chronic asthma. A small proportion of asthmatics develop a severe form of the disease and require a chronic long-term treatment with oral GC. These patients, ascribed as GC dependent asthmatics, present an ongoing inflammation of the airways. GC dependent asthma should be differentiated from GC resistant asthma. GC resistant asthmatics are defined as patients whose baseline pre-bronchodilation FEV1 of less than 70-80% predicted improves by less than 15% following 1-2 weeks of 40 mg prednisolone daily. The effects of GC are mediated by the GC receptor (GR) alpha. By a process called trans-activation they increase the transcription of genes involved in either beneficial processes or certain side effects. Through trans-repression, they inhibit the transcription factors, including nuclear factor kappa B (NF-kappa B), thereby decreasing the expression of many genes encoding inflammatory mediators. In addition to GR alpha, an isoform deficient in hormone binding has been isolated in humans and termed GR beta, which functions as a dominant negative inhibitor of GR alpha. However, to act as such, GR beta has to be more abundant than GR alpha, and conflicting data have been obtained concerning the relative levels of the two isoforms in cell lines and freshly isolated cells. It seems however that overexpression of GR beta may play a role in GC-resistant asthmatics, whereas in GC-dependent asthmatics, a predominant GR alpha expression has been consistently found. Thus the persistence of inflammation in GC-dependent asthma does not seem to be associated with an overexpression of GR beta but with a dysfunction of the trans-repression or trans-activation processes mediating the anti-inflammatory effects of GR alpha.

Asthma↗

Is there a role for glucocorticoid receptor beta in asthma?

Glucocorticoids (GCs) are routinely used as anti-inflammatory drugs in the treatment of asthma. They act through binding to glucocorticoid receptor alpha (GRalpha), which represses numerous genes encoding pro-inflammatory mediators. A hormone binding deficient GR isoform named GRbeta has been isolated in humans. When overexpressed by transfection, GRbeta may function as a dominant negative modulator of GRalpha. However, to act as such, GRbeta has to be more abundant than GRalpha, and conflicting data have been obtained concerning the relative levels of the two isoforms in cell lines and freshly isolated cells. Moreover, the dominant negative effect was not confirmed by independent laboratories. In GC-resistant asthmatics, GRbeta was expressed by an increased number of peripheral blood mononuclear cells (PBMCs), airway T cells, and cells found in skin biopsies of tuberculin responses. However, the relative amounts of GRalpha and GRbeta in these cells were not determined. In GC-dependent asthmatics, PBMCs expressed GRalpha predominantly. No cells containing higher levels of GRbeta than GRalpha have yet been reported in asthmatics. Even if the existence of such cells is demonstrated, the role of GRbeta in asthma will remain a matter of controversy because functional studies have given discrepant data.

Asthma↗

Apoptosis and airway inflammation in asthma.

Asthma is a disease characterized by a chronic inflammation of the airways and by structural alterations of bronchial tissues, often referred to as airway remodelling. The development of chronic airway inflammation in asthma depends upon the continuous recruitment of inflammatory cells from the bloodstream towards the bronchial mucosa and by their subsequent activation. It is however increasingly accepted that mechanisms involved in the regulation of the survival and apoptosis of inflammatory cells may play a central role in the persistent inflammatory process characterizing this disease. Increased cellular recruitment and activation, enhanced cell survival and cell:cell interactions are therefore the key steps in the development of chronic airway inflammation in asthma, and represent the major causes for tissue damge, repair and remodelling.

Animals↗

ICAM-1 and alpha3beta1 expression by bronchial epithelial cells and their in vitro modulation by inflammatory and anti-inflammatory mediators.

BACKGROUND: Adhesion molecules are involved in inflammatory and repair processes of the bronchial epithelium. ICAM-1 is mainly involved in inflammatory reactions, whereas integrins, such as alpha3beta1, are mainly involved in repair processes. METHODS: Using bronchial biopsies from 10 asthmatics and eight controls, we first evaluated by immunohistochemistry expression of alpha3beta1 and ICAM-1 in intact and damaged epithelium. Then, using the human pulmonary epithelial cell line WI-26 VA, we studied, by flow-cytometry, the modulation of ICAM-1 and alpha3beta1 expression, and, by ELISA, the release of fibronectin by proinflammatory cytokines, such as IL-5, and anti-inflammatory cytokines, such as IL-4, TGF-beta, and EGF. RESULTS: alpha3beta1 expression was slightly higher in asthma than in controls, as well as in damaged epithelium than in undamaged epithelium. ICAM-1 expression was higher in asthma than in controls, and similarly distributed in intact or damaged epithelium. In vitro, alpha3beta1 was significantly increased by TGF-beta, EGF, and IL-4, and significantly decreased by IL-5. Fibronectin release was significantly increased by TGF-beta and IL-4, unchanged by EGF, and slightly but significantly decreased by IL-5. ICAM-1 expression was significantly decreased by TGF-beta and IL-4, unchanged by EGF, and significantly increased by IL-5. CONCLUSIONS: These differences in adhesion molecule expression and fibronectin release may be important in epithelial cell inflammation and repair.

Adolescent↗

Glucocorticoid receptor alpha and beta in glucocorticoid dependent asthma.

Patients with glucocorticoid (GC)-dependent asthma present an ongoing inflammation of the airways despite chronic long-term treatment with oral GC. Interleukin (IL)-8 and granulocyte/macrophage colony-stimulating factor (GM-CSF) have been implicated in airway inflammation in severe asthma and their synthesis is normally repressed by GC. To further characterize the inflammatory process in GC-dependent asthma, we measured the release of IL-8 and GM-CSF by peripheral blood mononuclear cells (PBMC) of eight normal subjects, six untreated controlled asthmatics, six untreated uncontrolled asthmatics, and nine GC-dependent asthmatics. We show that PBMC from GC-dependent asthmatics released high amounts of these cytokines despite chronic in vivo exposure to GC (p < 0.001 versus normal subjects). In contrast, when untreated uncontrolled asthmatics were given a short course of oral GC, IL-8 and GM-CSF production was inhibited (p = 0.0078). Release of IL-8 and GM-CSF by PBMC of GC-dependent asthmatics was reduced after in vitro GC treatment (p < 0.002). We investigated whether the incapacity of GC to inhibit production of these cytokines in vivo was the result of a dysregulation of the glucocorticoid receptor (GR) in GC-dependent asthma. GRalpha and GRbeta are, respectively, the functional receptor and a putative dominant negative form of the receptor. Western blot and polymerase chain reaction (PCR) analyses indicated that GRalpha was expressed at similar level in all groups and was largely predominant over GRbeta. Thus, persistent release of IL-8 and GM-CSF in GC-dependent asthma is not associated with low expression of GRalpha or overexpression of GRbeta.

Adult↗

Evaluation of apoptosis of eosinophils, macrophages, and T lymphocytes in mucosal biopsy specimens of patients with asthma and chronic bronchitis.

BACKGROUND: Apoptosis regulates inflammatory cell survival, and its reduction contributes to the chronicity of an inflammatory process. Apoptosis is controlled by suppressing or inducing genes, such as bcl-2 and p53, respectively. OBJECTIVE: We sought to assess apoptosis of eosinophils, macrophages, and T lymphocytes in bronchial biopsy specimens from asthmatic subjects and to examine its regulation by evaluating the expression of B-cell lymphoma leukemia-2 (Bcl-2) and P53 proteins. We also sought to explore the relationships between cell apoptosis and GM-CSF, a cytokine able to increase eosinophil and macrophage survival. METHODS: Apoptosis in eosinophils, macrophages, and T lymphocytes was evaluated in bronchial biopsy specimens obtained from 30 asthmatic subjects, 26 subjects with chronic bronchitis, and 15 control subjects by combining the terminal deoxynucleotidyl transferase-mediated dNTP nick end-labeling technique and immunohistochemistry. The expression of P53, Bcl-2, and GM-CSF was studied through immunohistochemistry by using specific mAbs. RESULTS: The number of apoptotic eosinophils and macrophages was lower in subjects with asthma than in those with chronic bronchitis (P <.007 and P <.001, respectively) and inversely correlated with the clinical severity of asthma (P <.001 and P <.002, respectively). Few T lymphocytes were apoptotic in all groups studied. In asthma GM-CSF+ cells correlated with the number of nonapoptotic eosinophils and macrophages (P =.0001) and with the severity of the disease (P <.003). In asthma Bcl-2+ cells were higher than in control subjects and subjects with chronic bronchitis (P <.002 and P <.015, respectively), they outnumbered P53+ cells, and they correlated with the number of T lymphocytes (P <.001) and with the severity of the disease (P <.003). CONCLUSION: Airway inflammation in asthma is associated with an enhanced survival of different cell types caused by reduced apoptosis.

Adult↗

Glucocorticoid receptors in bronchial epithelial cells in asthma.

The expression of the glucocorticoid receptor (GR) in untreated or in steroid-dependent asthmatic patients is poorly understood. We therefore studied GR mRNA and protein levels in bronchial biopsies obtained from seven untreated asthmatic patients, seven control volunteers, and seven patients with chronic bronchitis. We also studied in bronchial epithelial cells obtained by brushing from 13 untreated asthmatics, 18 steroid-dependent asthmatics, 11 control volunteers, and 12 patients with chronic bronchitis, GR and heat shock protein 90 kD (hsp90) mRNA as well as the immunoreactivity of GR, intercellular adhesion molecule (ICAM-1), and granulocyte macrophage-colony-stimulating factor (GM-CSF). GR mRNA and protein level was similar in all subject groups in both biopsies and bronchial epithelial cells. Hsp90 mRNA level was also similar in all subject groups. ICAM-1 expression was significantly increased in bronchial epithelial cells from untreated asthmatics, but ICAM-1 was not expressed in those from steroid-dependent asthmatic patients. GM-CSF expression was significantly increased in bronchial epithelial cells from untreated and steroid-dependent asthmatic patients. GR expression within the airways is unaltered by oral long-term steroid treatment in asthma, but the expression of some but not all specific markers for asthma is modified by oral steroid.

Administration, Oral↗

Diversity among Opine-Utilizing Bacteria: Identification of Coryneform Isolates.

Bacteria were isolated from soil and crown gall tumors by selection in minimal medium with an opine, such as succinamopine or mannopine, as the sole carbon source. The isolates were characterized for the pattern of opine utilization and identified. They were classified as mannityl opine or imino diacid utilizers and exhibited specificity of utilization similar to that described previously for Agrobacterium species. A minority of isolates were gram negative and were identified as Agrobacterium or Pseudomonas species; most were gram positive and belonged to the coryneform group. These results indicate that any specific effect of opines on the ecology of Agrobacterium tumefaciens is modulated by activities of other types of soil- and plant-associated bacteria.

Journal Article↗