Extracorporeal shock waves increase markers of cellular proliferation in primary bronchial fibroblasts of COPD patients

COPD is due to a remodeling of small airways and destruction of the lung parenchyma with loss of the alveolar attachment as a result of pulmonary emphysema. Treatment of connective tissue fibroblasts with extracorporeal shock waves (ESW) increases their cellular proliferation and differentiation. To date no studies are available on ESW treatment of human primary bronchial fibroblasts from COPD and control subjects. Primary bronchial fibroblasts were obtained from bronchial biopsies from three patients with mild/moderate COPD and 3 control smokers with normal lung function. After stabilization for 24h, 1 ml of cell suspension (106 cells) from COPD and controls was treated in 2 ml tubes with a piezoelectric shock wave generator (energy level 0.3 mJ/mm2, 500 pulses). After treatment, viability was evaluated and the cells were re-cultured and followed for 4, 24, 48, and 72h. Cell growth (WST-1 test) and proliferative markers were analysed by qRT-PCR and ELISA tests in cell supernatants and cell lysates of ESW treated and non-treated cells. None of the molecules studied were significantly changed at mRNA level after ESW treatments. At protein level, cKit (CD117) at 24h (p=0.037) and procollagen-I at 4h (p=0.022) were significantly increased in ESW treated COPD fibroblasts compared to COPD non-treated ones. PCNA at 4h (p=0.051), Thy1(CD90) at 24h (p=0.031) and TGFβ1 at 72h (p=0.038) were significantly increased in ESW-treated control smokers fibroblasts compared to non-treated cells. These data show an increase of cell proliferation induced by extracorporeal shock waves in primary bronchial fibroblasts of both COPD and control smoking subjects.