PDGF C Is A Selective α Platelet-Derived Growth Factor Receptor Agonist That Is Highly Expressed in Platelet α Granules and Vascular Smooth Muscle

Objective— The platelet-derived growth factor (PDGF) family consists of four members, PDGF A, PDGF B, and 2 new members, PDGF C and PDGF D, which signal through the α and β PDGF receptor (PDGFR) tyrosine kinases. This study was performed to determine the receptor specificity and cellular expression profile of PDGF C. Methods and Results— PDGF C growth factor domain (GFD) was shown to preferentially bind and activate α PDGFR and activate β PDGFR when it is co-expressed with α PDGFR through heterodimer formation. An investigation of PDGF C mRNA and protein expression revealed that during mouse fetal development, PDGF C was expressed in the mesonephric mesenchyme, prefusion skeletal muscle, cardiac myoblasts, and in visceral and vascular smooth muscle, whereas in adult human tissues expression was largely restricted to smooth muscle. Microarray analysis of various cell types showed PDGF C expression in vascular smooth muscle cells, renal mesangial cells, and platelets. PDGF C mRNA expression in platelets was...