Sialyl-lactotetra: a novel cell surface marker of undifferentiated human pluripotent stem cells [Glycobiology and Extracellular Matrices]

May 19th, 2014 by Barone, A., Salȷo, K., Benktander, J., Blomqvist, M., Mansson, J.–E., Johansson, B. R., Molne, J., Aspegren, A., Bȷorquist, P., Breimer, M. E., Teneberg, S.

Cell surface glycoconjugates are used as markers for undifferentiated pluripotent stem cells. Here, antibody binding and mass spectrometry characterization of acid glycosphingolipids isolated from a large number (1x109 cells) of human embryonic stem cell (hESC) lines allowed identification of several novel acid glycosphingolipids, like the gangliosides sialyl-lactotetraosyl-ceramide and sialyl-globotetraosylceramide, and the sulfated glycosphingolipids sulfatide, sulf-lactosylceramide and sulf-globopentaosylceramide. A high cell surface expression of sialyl-lactotetra on hESC and human induced pluripotent stem cells (hiPSC) was demonstrated by flow cytometry, immunohistochemistry and electron microscopy, whereas sulfated glycosphingolipids were only found in intracellular compartments. Immunohisto-chemistry showed distinct cell surface anti-sialyl-lactotetra staining on all seven hESC lines and three hiPSC lines analyzed, while no staining of hESC-derived hepatocyte-like or cardiomyocyte-like cells was obtained. Upon differentiation of hiPSC into hepatocyte-like cells the sialyl-lactotetra epitope was rapidly down-regulated and not detectable after 14 days. These findings identify sialyl-lactotetra as a promising marker of undifferentiated human pluri-potent stem cells.