Figure 4.

Decreased protein levels of markers associated with receptor-mediated mitophagy after CS exposure. Differentiated human primary bronchial epithelial cells (PBEC) from non-COPD subjects (n = 3–4 donors) were exposed to smoke of one Marlboro Red cigarette (CS), or a mixture of acetaldehyde, acrolein, and formaldehyde (at concentrations equivalent to one cigarette), or air (control), under a continuous flow system using a puff-like exposure protocol. After recovery for 6 h or 24 h, whole cell lysates were harvested for analysis of (A,B,D,F) protein and (C,E,G) transcript abundance of key regulators involved in receptor-mediated mitophagy: BNIP3L, BNIP3, and FUNDC1. Representative Western blot images are shown for one replicate of one donor per experiment, reflective of the changes in all donors as quantified in the corresponding graph. Data are presented as mean fold change compared to air control ± s.e.m. The mean values of biological triplicates for each independent donor are represented by open circles, triangles, squares, or diamonds. Statistical differences between CS vs. air and the mixture of aldehydes vs. air were tested using a two-tailed paired parametric t-test. Statistical significance is indicated as * p < 0.05 and ** p < 0.01 vs. air (control).