Culture media

Western blot reagents were obtained from GE Healthcare (Pittsburgh, PA, USA). Fluorescent probes for caspase activity, caspase inhibitors, and annexin V assay kit were from BD Biosciences (San José, CA, USA). Culture media were from Lonza (Basel, Switzerland). MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide) and p38MAPK inhibitor (SB202190) were obtained from Sigma-Aldrich (St. Louis, MO, USA). Primary monoclonal rabbit antibodies against caspase 8 (dilution, 1:1,000; #4927), cleaved-caspase 9 (dilution, 1:1,000; #7237), MMP-2 (dilution, 1:1,000; #4022), MMP-9 (dilution, 1:1,000; #3852), p-p38 (dilution, 1:1,000; #9211), p38 (dilution, 1:1,000; #9212), and TIMP-1 (dilution, 1:1,000; #8946) were purchased from Cell Signaling Technology, Inc. (Danvers, MA, USA). Caspase 3 (dilution, 1:1,000; sc-7148), Bid (dilution, 1:1,000; sc-11423), Bcl-2 (dilution, 1:1,000; sc-783), Bcl-xL (dilution, 1:1,000; sc-634), and Bax (dilution, 1:1,000; sc-526) were purchased from Santa Cruz Biotechnology, Inc. (Dallas, TX, USA), and β-actin (dilution, 1:5,000; #A5441) was obtained from Sigma-Aldrich (St. Louis, MO, USA).
Anti-Ki67 (dilution 1:200) and Click-iT Tunel colorimetric IHC detection kit were from Thermo Fisher (Waltham, MA USA). DAB kit was provided from Vector laboratories (Burlingame, CA, USA).

Never-smoker human airway epithelial cells and culture media from Lonza (Basel, Switzerland) were cultured according to company’s instructions and used at passage 2 (P2). Normal Human Lung Fibroblasts from Promocell (Heidelberg, Germany) were cultured in accordance with the company’s instructions and were used at P4-P5. Normal Human Airway Smooth Muscle cells donated by Dr. Charis Charalambous (NHLI, Imperial College) were cultured in Dulbecco’s Modified Eagles Medium (DMEM, Sigma) supplemented with 10% fetal calf serum (FCS, Sigma, Poole, UK), 5% L-glutamine (200nM, Sigma) and penicillin/streptomycin (0.1 mg/ml, Sigma) and used at P4-P5 as described (Wiegman et al., 2015 (link)). All tissue was obtained with appropriate consent and its use approved by the Ethics Committee of the Royal Brompton and Harefeld National Health Service Trust.

Cell Type	Age	Sex
NHBE	69	F
NHBE	69	F
NHBE	53	M
NHLF	48	F
NHASM	65	M