Fig. 6
Elevated HE4 expression in CSE-exposed HBE cells was mediated by oxidative stress. A Pretreatment of NAC overtly alleviated CSE-induced HE4 increase (n = 3). B Different concentrations of H2O2 promoted HE4 expression (n = 3). C Pretreating NAC significantly mitigated H2O2-induced HE4 up-regulation (n = 3). Data are expressed as mean ± SEM. P-values were calculated using one-way ANOVA followed by Newman–Keuls test. *P < 0.05 and **P < 0.01 represent significant differences. HE4, human epididymis protein 4; CSE, cigarette smoke extract; HBE, human bronchial epithelial; DMSO, dimethyl sulfoxide; NAC, N-acetylcysteine