Live-Cell Imaging of Telocyte-like Cells in Primary Liver Cell Cultures.

Telocytes are small mesenchymal cells with unknown hepatic functions. In primary cultures of rat hepatocytes and non-parenchymal liver cells (NPLC), we observed, at a very low incidence, small-sized, highly motile cells. Because these cells fulfill ultrastructural/morphological 'telocytes hallmarks', foremost their minuteness and the presence of very thin telopodia, we refer to them as hepatic telocyte-like cells (hTCLs). Unique among hepatic cells and beyond these telocyte characteristics is their high motility and pronounced cell plasticity. Surprisingly, hTCLs display an exceptional exploratory behavior by moving along/between cell borders as well as beneath cells. Their fast motility apart, hTCLs share structural and behavioral similarities with Kupffer cells/macrophages in NPLC cultures, suggesting a relationship between both cell types that needs to be addressed by further investigation. In EGF/insulin-treated hepatocyte cultures, hTCLs' motility declines, and the cells adopt an extremely small cell body with very long processes. In cultured hepatocyte monolayers, hTCLs associate with dividing hepatocytes, especially during advanced mitosis (cytokinesis). In conclusion, our observations demonstrate the presence of a small population of highly mobile, telocyte-like cells in liver-derived cell cultures, and a correlative association between hTCLs and hepatocytes, hypothetically accounting for an integrative function of this cell type.