Figure 2.

In SCD, repeating sickling cycles result in increased hemolysis. Hemolysis byproducts such as heme induce PlGF expression in multiple cell types (for simplicity purposes only erythroblasts are depicted). Secreted PlGF is a ligand for FLT-1 receptor and triggers the expression of ET-1, PAI-1, leukotrienes and cytochemokines, affecting the physiology of multiple organs. AH, Airway hyperreactivity; PH, Pulmonary hypertension; FLT1/VEGFR1, Fms related receptor tyrosine kinase 1; PlGF, placenta growth factor; ET-1, endothelin 1; PAI-1/Serpine1, plasminogen activator inhibitor 1.