A novel macrolide derivative ameliorates smoke-induced inflammation and emphysema by inhibiting NF-κB activation.

Although inflammation and emphysema in patients with chronic obstructive pulmonary disease (COPD) can be ameliorated by antibiotics such as erythromycin, the impact of drug resistance is still controversial. We aimed to evaluate the role of F528, a new macrolide derivative without antibacterial effect, in cigarette smoke (CS)-induced pulmonary inflammation and emphysema in a mouse model, as well as in a macrophage cell line. The inflammatory cell number and cell type in the BALF were counted, and the levels of cytokines in the BALF and cultured cell medium were measured by ELISA. The degree of emphysema and apoptosis was evaluated by H&E and immunohistochemical staining, respectively. The lung function of the mice was evaluated by a small animal lung function meter. Furthermore, the expression levels of MMP-2, MMP-9, and phospho-NF-κB in the cells and lung tissue were measured by Western blot and qRT-PCR. In the BALF of the CS-induced pulmonary inflammation and emphysema model, the numbers of inflammatory cells and cytokines were significantly decreased after F528 intervention. F528 intervention also significantly protected lung function from CS-induced emphysema, while the mean lining interception (MLI) of the F528-treated CS group was significantly lower than that of the vehicle-treated CS group. In addition, F528 treatment reduced the phosphorylation of NF-κB induced by smoke, and the expression of MMP-2 and MMP-9 was also obviously decreased by F528 treatment. We therefore conclude that F528 reduces cigarette smoke-induced inflammation and emphysema in vivo and in vitro through inhibition of the activation of NF-κB.