TY - JOUR
T1 - Carbocisteine inhibits oxidant-induced apoptosis in cultured human airway epithelial cells
AU - Yoshida, Motoki
AU - Nakayama, Katsutoshi
AU - Yasuda, Hiroyasu
AU - Kubo, Hiroshi
AU - Kuwano, Kazuyoshi
AU - Arai, Hiroyuki
AU - Yamaya, Mutsuo
PY - 2009/9
Y1 - 2009/9
N2 - Background and objective: Increased oxidant levels have been associated with exacerbations of COPD, and L-carbocisteine, a mucolytic agent, reduces the frequency of exacerbations. The mechanisms underlying the inhibitory effects of L-carbocisteine on oxidant-induced COPD exacerbations were examined in an in vitro study of human airway epithelial cells. Methods: In order to examine the antioxidant effects of L-carbocisteine, human tracheal epithelial cells were treated with L-carbocisteine and exposed to hydrogen peroxide (H 2O2). Cell apoptosis was assessed using a cell death detection ELISA, and the pathways leading to cell apoptosis were examined by measurement of caspase-3 and caspase-9 by western blot analysis with fluorescent detection. Results: The proportion of apoptotic cells in human tracheal epithelium was increased in a concentration- and time-dependent manner, following exposure to H2O2. Treatment with L-carbocisteine reduced the proportion of apoptotic cells. In contrast, H2O 2 did not increase the concentration of LDH in supernatants of epithelial cells. Exposure to H2O2 activated caspase-3 and caspase-9, and L-carbocisteine inhibited the H2O2-induced activation of these caspases. L-carbocisteine activated Akt phosphorylation, which modulates caspase activation, and the inhibitors of Akt, LY294002 and wortmannin, significantly reversed the inhibitory effects of L-carbocisteine on H2O2-induced cell apoptosis. Conclusions: These findings suggest that in human airway epithelium, L-carbocisteine may inhibit cell damage induced by H2O2 through the activation of Akt phosphorylation. L-carbocisteine may have antioxidant effects, as well as mucolytic activity, in inflamed airways.
AB - Background and objective: Increased oxidant levels have been associated with exacerbations of COPD, and L-carbocisteine, a mucolytic agent, reduces the frequency of exacerbations. The mechanisms underlying the inhibitory effects of L-carbocisteine on oxidant-induced COPD exacerbations were examined in an in vitro study of human airway epithelial cells. Methods: In order to examine the antioxidant effects of L-carbocisteine, human tracheal epithelial cells were treated with L-carbocisteine and exposed to hydrogen peroxide (H 2O2). Cell apoptosis was assessed using a cell death detection ELISA, and the pathways leading to cell apoptosis were examined by measurement of caspase-3 and caspase-9 by western blot analysis with fluorescent detection. Results: The proportion of apoptotic cells in human tracheal epithelium was increased in a concentration- and time-dependent manner, following exposure to H2O2. Treatment with L-carbocisteine reduced the proportion of apoptotic cells. In contrast, H2O 2 did not increase the concentration of LDH in supernatants of epithelial cells. Exposure to H2O2 activated caspase-3 and caspase-9, and L-carbocisteine inhibited the H2O2-induced activation of these caspases. L-carbocisteine activated Akt phosphorylation, which modulates caspase activation, and the inhibitors of Akt, LY294002 and wortmannin, significantly reversed the inhibitory effects of L-carbocisteine on H2O2-induced cell apoptosis. Conclusions: These findings suggest that in human airway epithelium, L-carbocisteine may inhibit cell damage induced by H2O2 through the activation of Akt phosphorylation. L-carbocisteine may have antioxidant effects, as well as mucolytic activity, in inflamed airways.
KW - Antioxidant
KW - Apoptosis
KW - Chronic obstructive pulmonary disease
KW - Emphysema
KW - Infection and inflammation
KW - Mucolytic
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U2 - 10.1111/j.1440-1843.2009.01594.x
DO - 10.1111/j.1440-1843.2009.01594.x
M3 - Article
C2 - 19664007
AN - SCOPUS:70049107547
VL - 14
SP - 1027
EP - 1034
JO - Respirology
JF - Respirology
SN - 1323-7799
IS - 7
ER -