Potential significance of telocytes in the pathogenesis of lung diseases.

Multiple cells play critical roles in the pathogenesis of lung diseases, even though the exact mechanisms are still not clear. Telocytes are characterized by telopodes, which are thin and long prolongations, and a small amount of cytoplasm rich with mitochondria, as shown by immune-positive staining against CD34, c-kit and vimentin. Telocytes have been found in many organs of mammals, including the trachea and lung. This report summarizes the latest findings associated with telocytes, with a special focus on the lung, and demonstrates that telocytes exist in the smooth muscle layer under cartilage and bronchiole in the lung, and also in the interstitial space of alveoli. Telocytes have a mediate connection with epithelial cells and direct connection with smooth muscle cells both in blood vessels and bronchiole in the lung. Telocytes also have a close relationship with other cell types, such as immune cells and stem cells. Telopodes appear with dichotomous branching and alternation of podom and podomer, forming a 3D network structure with complex homo- and hetero-cellular junctions. All characteristics of telocytes in lung tissue indicate that telocytes may play a potential, but important, role in the pathogenesis of lung diseases.