Human amnion-derived cells: prospects for the treatment of lung diseases

Lung diseases represent a significant burden of morbidity and mortality worldwide. Current therapies have not proven adequate in the long term and are often associated with significant side effects. There has been recent interest in the regenerative/reparative potential of cell-based therapies, including cells derived from the placental tissues. Amnion-derived cells are fetal-derived and characterized by expression profile and differentiative capacity of pluripotent cells. Moreover, because placenta is discarded after delivery, they represent an ethical source for the purposes of regenerative medicine. Amnion-derived cells are endowed with immunomodulatory, anti-inflammatory, anti-scarring and antibacterial properties, which may explain many of the beneficial effects observed with administration of the cells in animal models for a large number of inflammatory diseases. Both human amniotic epithelial cells (hAEC) and mesenchymal stromal cells (hAMSC) have been shown to acquire in vitro and in vivo some characteristics of epithelial cells, i.e. CFTR (cystic fibrosis transmembrane conductance regulator) and surfactant proteins. Administration of hAEC or hAMSC in vivo in the bleomycin-induced lung injury model has proven their therapeutic effects in term of reduction of pulmonary fibrosis and inflammation, as well as recovery of lung mechanical function. Many biological and clinical information have to be gathered before proposing amnion-derived cells in the clinic for the treatment of acute and chronic lung diseases.