PDGF-D is the fourth member of the PDGF family that binds to and activates its cognate PDGFR-β. PDGF-D is secreted as a homodimer and needs to be proteolytically processed for receptor binding. PDGF-D is expressed in many tissues and cells such as artery medial smooth muscle cells, endothelial cells, and fibroblast cells. Many studies have reported that PDGF-D plays a role in a variety of biological processes such as epithelial to mesenchymal transition (EMT) during the tumor progression, inflammation, angiogenesis, and etc (Li X. et al., Cytokine Growth Factor Rev., 2003).

We previously showed that PDGF-D expression was upregulated during pathological angiogenesis and inhibition of PDGF-D suppressed both choroidal and retinal neovascularization (Kumar A. et al., J Biol Chem., 2010).

We are trying to understand a number of important questions; precise roles of PDGF-D during developmental stages, similarity or difference of signaling pathways compared with other PDGF family, transcription profiles in different cell types, and biological functions of blood vessel maturation with PDGF-C.