TY - JOUR T1 - The long-acting β2-agonist formoterol re-establishes the anti-proliferative effect of glucocorticoids in asthmatic airway smooth muscle cells (ASMC) JF - European Respiratory Journal JO - Eur Respir J VL - 38 IS - Suppl 55 SP - 3446 AU - Michael Roth AU - Jun Zhong AU - Chong S'ng AU - Michael Tamm Y1 - 2011/09/01 UR - http://erj.ersjournals.com/content/38/Suppl_55/3446.abstract N2 - Background: Asthma is characterized by an increased mass of ASMC which show increased proliferation in vitro. As previously reported, glucocorticoids do not have a significant anti-proliferative effect on ASMC of asthmatics while although their anti-inflammatory efficacy is maintained.Methods: We assessed whether the addition of the long-acting β2-agonist formoterol modifies the anti-proliferative efficacy of glucocorticoids (beclomethasone, budenoside, fluticasone). Primary human ASMC lines from asthmatics and controls were set up from bronchoscopic lung biopsies.Results: Serum deprived sub-confuent cells were stimulated by 5% serum with or without a single drug or combination for a further 48 and 72 hrs. Serum alone increased cell proliferation in healthy control cells by 65% (48 hrs) and 81% (72 hrs); a significantly higher proliferation response was seen in asthmatic ASMC (82% at 48 hrs; 123% at 72 hrs). In the presence of different glucocorticoids alone serum-induced proliferation was significantly reduced in healthy cells (max. 48%) but not in asthmatic ASMC. Treatment with formoterol alone reduced serum-induced proliferation by max. 24% at any time point, with no differences between asthmatic and healthy ASMC. When formoterol was combined with fluticasone a 78% reduction of ASMC proliferation was achieved.Conclusions: Our results show that the β2-agonist formoterol re-establishes the anti-proliferative effect of fluticasone in asthmatic airway smooth muscle cells. This synergistic action may exert an anti-remodeling effect on the asthmatic airway supporting the clinical benefit of combination therapy. ER -