The C6 rat glioma cell line is broadly used as a model in studies of glial cell differentiation. In the present study we demonstrated a significantly higher total cellular, but especially membrane-associated, activity of dipeptidyl peptidase IV in differentiated C6 cells in comparison with their proliferating counterparts.
The majority, but not all, of enzyme isoelectric focusing isoforms from differentiated C6 cells displayed a substantially higher activity compared to the proliferating cells, with G-P-NHMec as the substrate. Non-denaturing polyacrylamide gradient gel electrophoresis showed the presence of one major peak of activity, dipeptidyl peptidase IV (M-r of about 220000), in both proliferating and differentiated C6 cells.
The results indicate that dipeptidyl peptidase IV regulation is associated with C6 rat glioma cell differentiation.