Regulation of EPCs: The Gateway to Blood Vessel Formation

Figure 2

The FOXO family and EPC apoptosis. The balance between active and inactive FOXO dictates apoptosis in EPCs. Akt activity is central to this regulation with abundance of the phosphorylated inactive form of FOXOs resulting in reduced cellular apoptosis. Certain drugs and blood sugar levels can tip the balance of FOXOs in EPCs. (a) Statin treatment of patients with CAD stimulates Akt activity and in turn FOXO4 phosphorylation, culminating in reduced EPC apoptosis and amelioration of EPC number in circulation. (b) Moreover, hyperglycemia and scleroderma impair Akt activation and subsequent phosphorylation of FOXO1 and FOXO3a, respectively. This results in an abundance of active FOXO1 and FOXO3a leading to elevated EPC apoptosis and reduction in EPC number.