Histopathologic changes of lung tissues in rats of various groups. (A) Control group (group I). (B) Emphysema group (group II). Airspace was markedly enlarged and the amount of alveoli was decreased after cigarette-smoke exposure and intratracheal LPS instillation. (C) Emphysema + rAFMSC transplantation for 20 days (group III). The features of emphysema were partly diminished after rAFMSC transplantation for 20 days. (D) Emphysema + rAFMSC transplantation for 40 days (group IV). The features of emphysema were decreased substantially after rAFMSC transplantation for 40 days. Scale bars, 200μm.