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Biomedical subjects

Celine Bergeron

Publications and source records attributed to Celine Bergeron.

8 recordsLinked to original sources

Effects of hydrofluoroalkane and dry powder-formulated corticosteroids on sputum inflammatory markers in asthmatic patients.

BACKGROUND: Inhaled corticosteroids are powerful drugs that can suppress airway inflammation in asthmatic patients. Deposition of most of the inhaled corticosteroid occurs mainly in the central airways. However, a new hydrofluoroalkane formulation of beclomethasone dipropionate (HFA-BDP) is preferentially deposited in the distal airways. Inflammatory characteristics of induced sputum have been shown to differ in samples collected early after sputum induction compared with later. OBJECTIVE: To compare the effects of HFA-BDP and budesonide in a dry powder inhaler (DPI-BUD) on inflammatory cells and inflammatory cytokine expression in early and late induced sputa compared with placebo. METHODS: Seventeen patients with mild, intermittent bronchial asthma were randomly assigned to two treatment groups: eight patients received HFA-BDP and nine patients received DPI-BUD. Each patient was treated with one of the active treatments and placebo (for four weeks), with a two-week washout interval in between. Inflammatory cells and expression of interleukin (IL)-4 and IL-5 were measured in early and late induced sputa before and after active treatment, as well as before and after placebo treatment using immunocytochemistry and in situ hybridization. RESULTS: Compared with placebo, eosinophils were significantly reduced in both early and late induced sputa after HFA-BDP treatment (P<0.05), whereas DPI-BUD had a significant effect only on early induced sputum. Both HFA-BDP and DPI-BUD decreased IL-4 expression in early and late induced sputa, but the effect was more prominent with HFA-BDP. IL-5 expression was reduced in both early and late induced sputa after HFA-BDP treatment. DPI-BUD significantly decreased IL-5 expression in early but not in late induced sputum. The number of lymphocytes was not altered by either treatment. CONCLUSIONS: HFA-BDP reduced eosinophilic inflammation and T helper 2-type cytokine expression in both early and late induced sputa, whereas the effect of DPI-BUD on inflammation was predominantly demonstrated in early induced sputum.

Administration, Inhalation↗

Evidence of remodeling in peripheral airways of patients with mild to moderate asthma: effect of hydrofluoroalkane-flunisolide.

BACKGROUND: We have shown previously that inflammation in asthma is not restricted to central airways but can also be demonstrated in peripheral airways. It is not clear whether inflammation of the peripheral airways is associated with structural changes and whether this remodeling process can be modulated by deposition of inhaled corticosteroids (ICSs). OBJECTIVES: To compare remodeling in peripheral and central airways and to investigate the effects of hydrofluoroalkane (HFA)-ICS on remodeling at these sites. METHODS: Transbronchial and endobronchial biopsies were obtained from 12 patients with mild to moderate asthma before and after a 6-week course of HFA-ICS (flunisolide). Total collagen deposition, expression of collagen III, TGF-beta, and alpha-smooth muscle actin were examined by using Van Gieson staining and immunocytochemistry, respectively. RESULTS: Total collagen occupied 37.7% of the wall area of peripheral airways, compared with 54.5% of the wall area of central airways (P = .04). There was no significant difference in central versus peripheral airways for collagen III or alpha-smooth muscle actin immunoreactivity and in the number of TGF-beta(+) cells in the submucosa. The only significant effect of HFA-flunisolide was a decrease in alpha-smooth muscle actin area in peripheral airways (13.4% vs 4.6%; P = .01) that correlated with the percentage increase in forced expiratory flow at 25% to 75% of vital capacity (r(s) = -1.00; P = .00). CONCLUSION: Our data show that there is a considerable degree of airway remodeling in peripheral airways in patients with asthma and confirm the inability of ICS to modulate collagen deposition and TGF-beta expression. Treatment with HFA-flunisolide is associated with a significant decrease in the expression of alpha-smooth muscle actin in peripheral airways, which correlated with improvement in peripheral airway function.

Actins↗

Oral corticosteroids decrease eosinophil and CC chemokine expression but increase neutrophil, IL-8, and IFN-gamma-inducible protein 10 expression in asthmatic airway mucosa.

BACKGROUND: Cytokines and chemokines have been implicated in the pathogenesis of asthma. Inhaled corticosteroids have been shown to decrease the number of eosinophils and to downregulate T H 2 cytokines but to increase neutrophils. The effect of corticosteroids on chemokine expression in asthma has not yet been investigated. OBJECTIVE: We sought to investigate the effect of a 2-week course of oral corticosteroid (methylprednisolone, 40 mg/d) on the expression of CXC chemokines (IL-8 and IFN-gamma-inducible protein 10 [IP-10]) and CC chemokines (eotaxin and monocyte chemotactic proteins [MCPs] 1-4) in endoscopic biopsy specimens of 13 patients with moderate-to-severe asthma. METHODS: CD3, major basic protein, and elastase immunoreactivities were monitored before and after treatment by using immunocytochemistry. Eotaxin, IL-8, IP-10, MCP-1, MCP-2, MCP-3, and MCP-4 mRNA expression in epithelium and submucosa were studied by using in situ hybridization. RESULTS: Corticosteroids reduced the number of CD3-positive T cells and major basic protein-positive eosinophils ( P < .05), whereas the number of neutrophils were increased ( P < .05). Corticosteroids also reduced the number of eotaxin ( P < .05), MCP-3, and MCP-4 mRNA-positive cells ( P < .001) in the epithelium and subepithelium. However, corticosteroids caused a significant increase in the epithelial expression of IL-8 ( P < .001), IP-10 ( P < .05), and MCP-2 mRNAs ( P < .01). Corticosteroids had no effects on MCP-1 mRNA expression. CONCLUSION: Our results demonstrate the dual nature of corticosteroids. Although corticosteroids can downregulate the expression of some asthma-associated chemokines, such as eotaxin, MCP-3, and MCP-4, they can also upregulate the expression of other chemokines, including IL-8, IP-10, and MCP-2. The failure of oral corticosteroids to inhibit IL-8 mRNA expression might contribute to persistent airway neutrophilia observed in patients with moderate-to-severe asthma, despite treatment with corticosteroids.

Administration, Oral↗

Increased expression of the calcium-activated chloride channel hCLCA1 in airways of patients with obstructive chronic bronchitis.

BACKGROUND: Interleukin (IL)-9 and its effect on enhancing the human calcium-activated chloride channel 1 (hCLCA1) expression have been shown to induce mucin production. Increased expression of hCLCA1 may, in turn, contribute to mucus overproduction in chronic obstructive pulmonary disease (COPD) with a chronic bronchitis (CB) phenotype. OBJECTIVE: To determine the expression of IL-9, IL-9 receptor (IL-9R), hCLCA1 and mucoglycoconjugates in COPD. METHODS: Bronchial biopsies were obtained from six patients with obstructive CB and six healthy control subjects. IL-9, IL-9R and hCLCA1 expression were detected using immunohistochemistry. Additionally, in situ hybridization was performed to determine the expression of hCLCA1 messenger RNA. Mucin production was assessed using periodic acid-Schiff staining. RESULTS: There was a significantly higher number of IL-9 immunoreactive cells in the submucosa of patients with COPD than that of healthy control subjects (P<0.05). Also, a significant increase in the expression of IL-9R, hCLCA1 (protein and messenger RNA) and mucin (periodic acid-Schiff-positive cells) was noted in the bronchial epithelium of patients with COPD compared the control subjects (P<0.05). CONCLUSION: Increased expression of IL-9, IL-9R and hCLCA1 in the bronchial mucosa of patients with obstructive CB suggests that mucus overproduction in this disease may be, at least in part, due to hCLCA1.

Aged↗

IL-9 in allergic inflammation.

Th2 type cytokines such as interleukin (IL)-4, IL-5, IL-9, and IL-13 are important mediators in allergic inflammation. The present review will focus on the role of IL-9 in allergic inflammation. The structure and genomic architecture of IL-9 and its receptor, the source of IL-9 and its regulation as well as its effects on different cell types will be reviewed. Furthermore, the specific role of IL-9 in allergic diseases and the potential therapeutic approach of blocking IL-9 will be discussed.

Animals↗