Fig. 4.

GSK-3β promotes vSMC proliferation and apoptosis. a The effect of GSK-3β inhibition with SB-216763 (25 μM) on vSMC cell proliferation (24 h), PCNA expression (24 h) and cell number (48 h) following exposure to 10% FCS. Proliferation was assessed following FACS analysis using the Vybrant™ CFDA-SE Cell Tracer Kit Cell, PCNA levels by western blot and cell counting using a hemocytometer. The effect of pharmacological inhibition of GSK-3β activity with SB-216763 (25 μM) in the absence or presence of forced expression of Notch3 ICD on serum-stimulated vSMC proliferation was also assessed after 48 h. b The effect of pharmacological inhibition of GSK-3β activity with SB-216763 (25 μM) on the number of apoptotic nuclei following exposure to serum (10% FCS) by FACS analysis using a Vybrant™ Apoptosis Alexa Fluor 488™ Annexin V and propidium iodide assay; an effect that was reversed following ectopic expression of constitutively active mut.GSK-3β (GSK-3β-S9A) and c the effect of pharmacological inhibition of GSK-3β activity with SB-216763 (25 μM) following exposure to low serum (0.5% FCS) by FACS analysis using a Vybrant™ Apoptosis Alexa Fluor 488™ Annexin V and propidium iodide assay in the absence or presence of forced expression of Notch3 ICD. The cumulative data represents the mean values from three independent experiments ±SEM, *p < 0.05 versus control, #p < 0.05 versus SB-216763, §p < 0.05 versus Notch3 ICD