Biomedical subjects

L M Reece

Publications and source records attributed to L M Reece.

4 recordsLinked to original sources

PubMed1999

Mitochondrial glutathione modulates TNF-alpha-induced endothelial cell dysfunction.

The effect of glutathione (GSH) depletion by L-buthionine-[S,R]-sulphoximine (BSO) on tumor necrosis factor-alpha (TNF-alpha)-induced adhesion molecule expression and mononuclear leukocyte adhesion to human umbilical vein endothelial cells (HUVECs) was investigated. Cells with marked depletion of cytoplasmic GSH, but with an intact pool of mitochondrial GSH, only slightly enhanced TNF-alpha-induced E-selectin and vascular cell adhesion molecule-1 (VCAM-1) expression, compared with the control. However, TNF-a-induced expression of both molecules was markedly enhanced when the mitochondrial GSH pool was diminished to <15% of the control. In contrast, TNF-alpha-induced intercellular adhesion molecule-1 (ICAM-1) expression was not affected by the depletion of either cytoplasmic or mitochondrial GSH. Marked enhancement of TNF-alpha-induced adhesion molecule expression by the depletion of mitochondrial GSH resulted in increased in mononuclear leukocyte adhesion to treated HUVECs, compared with the control. These effects parallel reactive oxygen species (ROS) formation by the depletion of mitochondrial but not cytoplasmic GSH. Our findings demonstrate that depletion of mitochondrial GSH renders more ROS generation in HUVECs, and mitochondrial GSH modulates TNF-alpha-induced adhesion molecule expression and mononuclear leukocyte adhesion in HUVECs.

Buthionine Sulfoximine↗

PubMed1996

Intranasal fluticasone propionate inhibits recovery of chemokines and other cytokines in nasal secretions in allergen-induced rhinitis.

BACKGROUND: Allergen-induced nasal responses are associated with the recovery of proinflammatory mediators and cytokines. In recent years, a distinct group of chemotactic cytokines, chemokines, has been the focus of intense investigation as to their possible role in the pathogenesis of allergic diseases. Although corticosteroids have been known to be effective in the treatment of allergic diseases, their mechanism(s) of action has not been fully elucidated. OBJECTIVES: To study the effect of topical fluticasone on the recovery of chemokines (IL-8, MIP-1 alpha, and RANTES) and other cytokines (IL-1 beta, IL-6, and GM-CSF) from nasal mucosa following allergen challenge. To correlate the improvement of rhinitis symptoms with cytokine levels during early-phase and late-phase allergic responses. METHODS: A randomized, double-blind, placebo-controlled crossover study of fluticasone propionate, 200 micrograms q d, was performed in ten subjects with allergic rhinitis. Allergen challenge was administered after 1 week of treatment. Nasal secretions were collected immediately after challenge and during the late-phase reactions; symptom scores were recorded simultaneously. Nasal cytokines were assayed by specific ELISA. RESULTS: The allergen challenge caused early-phase and late-phase allergic reactions and increased recovery of IL-1 beta, IL-6, IL-8, RANTES, MIP-1 alpha, and GM-CSF from the nasal mucosa. Intranasal fluticasone inhibited the allergen-induced increase in nasal symptoms. This was associated with decreases in cytokine recovery. A significant correlation was observed between decreases in cytokine levels and in symptom scores after treatment. CONCLUSION: Our results suggest that treatment with topical fluticasone propionate inhibits allergen-induced nasal responses and the associated increase in the production/secretion of chemokines and other proinflammatory cytokines.

Administration, Topical↗

PubMed1995

Secretion of chemokines and other cytokines in allergen-induced nasal responses: inhibition by topical steroid treatment.

We have demonstrated the detection of proallergic cytokines in the nasal secretions after antigen challenges. Our aim was to determine the secretion kinetics of chemokines (interleukin [IL]-8, macrophage inflammatory protein-1 alpha [MIP-1 alpha], and RANTES) and other cytokines (IL-1 beta and granulocyte/macrophage colony-stimulating factor [GM-CSF] after allergen challenges and their inhibition by steroid therapy. Ten allergic patients were given either beclomethasone dipropionate (BDP) or placebo in a double-blind, randomized, crossover manner. Allergen challenges were performed after 1 wk of treatment. Nasal secretions were collected serially for 11 h after allergen challenge by a matrix method. Subjects maintained symptom scores at each time point of nasal secretion recovery. Cytokines were measured by specific enzyme-linked immunosorbent assays. The mean peak values for each cytokine and total symptom scores during the early (ER) and/or late-phase reactions (LPR) were significantly reduced during the BDP treatment period (p < 0.05). The levels of cytokine correlated (p < 0.05) with corresponding total symptom scores during ER (IL-1 beta and MIP-1 alpha) and LPR (all cytokines). Our findings document local elevations of IL-1 beta, GM-CSF, and chemokines in the nasal secretions after allergen challenges and their inhibition by steroids. We speculate that the inhibition of cytokine production and secretion in the nasal mucosa may contribute to the clinical efficacy of topical steroids.

Beclomethasone↗

PubMed1994

Interleukin-1 receptor antagonist protein inhibits the synthesis of IgE and proinflammatory cytokines by allergen-stimulated mononuclear cells.

The ability of interleukin-1 (IL-1) to activate diverse cell populations supports its role as a preeminent cytokine in the pathogenesis of chronic inflammation. In this study, we investigated the role of Il-1 and IL-1 receptor antagonist protein (IRAP) in the regulation of allergen-induced synthesis of IgE and proinflammatory cytokines. The temporal expression of IL-1 beta and IRAP during 5-day allergen-activated peripheral mononuclear cell (PMNC) cultures suggested differential production of the two cytokines. To determine the influence of IRAP on IL-1-mediated cellular responses, we cultured PMNC from allergic donors with specific allergens in the presence or absence of IRAP pretreatment. Culture supernatants were assayed for IgE and cytokines using specific enzyme-linked immunosorbent assay. IRAP at concentrations 0.01, 0.1, and 1 microgram/ml decreased the allergen-stimulated IgE synthesis by 33 +/- 7%, 50 +/- 7%, and 66 +/- 5%, respectively (P < 0.05). Increasing the concentration of allergen did not affect the reduction in IgE synthesis observed in the presence of IRAP. Lipopolysaccharide-stimulated IgE synthesis was also significantly inhibited by IRAP (P < 0.05). In parallel experiments, anti-IL-1 beta monoclonal antibody showed a comparable inhibitory pattern on IgE synthesis (P < 0.05). IRAP inhibited the synthesis of interleukin-6, tumor necrosis factor-alpha, and granulocyte/macrophage colony-stimulating factor in a dose-dependent manner (P < 0.05); the mean inhibition was 31 +/- 4%, 75 +/- 5%, and 88 +/- 2%, respectively, at 1 microgram/ml of IRAP.(ABSTRACT TRUNCATED AT 250 WORDS)

Allergens↗