Effects of CK2 inhibition in cultured fibroblasts from Type 1 Diabetic patients with or without nephropathy.

CK2 is a multifunctional, pleiotropic protein kinase involved in the regulation of cell proliferation and survival. Since fibroblasts from Type 1 Diabetes patients (T1DM) with Nephropathy exhibit increased proliferation, we studied cell viability, basal CK2 expression and activity, and response to specific CK2 inhibitors TBB (4,5,6,7-tetrabenzotriazole) and CX4945, in fibroblasts from T1DM patients either with (T1DM+) or without (T1DM-) Nephropathy, and from healthy controls (N). We tested expression and phosphorylation of CK2-specific molecular targets. In untreated fibroblasts from T1DM+, the cell viability was higher than in both N and T1DM-. CK2 inhibitors significantly reduced cell viability in all groups, but more promptly and with a larger effect in T1DM+. Differences in CK2-dependent phosphorylation sites were detected. In conclusion, our results unveil a higher dependence of T1DM+ cells on CK2 for their survival, despite a similar expression and a lower activity of this kinase compared with those of normal cells.