TY - JOUR T1 - Role of mitochondrial biogenesis in asthmatic airway smooth muscle proliferation: <em>Forever young</em> JF - European Respiratory Journal JO - Eur Respir J VL - 44 IS - Suppl 58 SP - 3226 AU - Valerie Siao AU - Thomas Trian AU - Patrick Berger AU - Michael Fayon Y1 - 2014/09/01 UR - http://erj.ersjournals.com/content/44/Suppl_58/3226.abstract N2 - Increased bronchial smooth muscle mass is one of the key structural features of severe asthma. In adults, asthmatic airway smooth muscle cells (ASMC) demonstrate greater mitochondrial biogenesis associated with an increase in ASMC proliferation rate vs non-asthmatic ASMC. There is no evidence that such a difference between asthmatic and non-asthmatic ASMC occurs in pre-school children.The primary aim of the study was to compare asthmatic and non-asthmatic ASMC proliferation and mitochondrial biogenesis in adults and pre-school children. The secondary aim was to assess the effect of factors released by the epithelium upon stimulation by environmental factors (rhinovirus RV, house dust mite HDM) on ASMC proliferation.We cultured ASMC and bronchial epithelial cells(BEC) obtained by endobronchial biopsy from children and adults with severe asthma or no. We studied ASMC proliferation (cell counting and CFSE dye assay) in 10% fetal bovine serum and after the addition of the BEC culture supernatant obtained after RV infection, HDM exposure or both. Mitochondrial mass and biogenesis were determined by western blot.ASMC proliferation and mitochondrial mass were increased in asthmatic adults, asthmatic and control children ASMC vs control adults, with a cell doubling time of 35.0±2.5 h, 24.8±1.9h, 22.6±2.6h vs 47.4±4.4h (p&lt;0.05) and a porine rate at 50%, 53%, 52% vs 20%. RV and HDM exposure induced an increase of 120,5% and 107.7% compared to the basal proliferation rate in asthmatic subjects only.As previously described in adult asthmatics, ASMC proliferation is enhanced in both asthmatic and non-asthmatic children. This is associated with an increase in mitochondrial mass and biogenesis. ER -