platelet-derived growth factor D (PDGF D, iris-expressed growth factor, spinal cord-derived growth factor B, SCDGF-B, PDGFD, IEGF, SCDGFB, MSTP036, UNQ1899/PRO4345)

^[1]

Function

potent mitogen for cells of mesenchymal origin
binding to its affinity receptor elicits a variety of cellular responses
released by platelets upon wounding & plays an important role in stimulating adjacent cells to grow, thus heals the wound
activated by proteolytic cleavage
cleavage after Arg-247 or Arg-249 by urokinase plasminogen activator gives rise to the active form
active form acts as a specific ligand for PDGF receptor beta
induces macrophage recruitment, increased interstitial pressure, & blood vessel maturation during angiogenesis

homodimer, disulfide-linked
belongs to the PDGF/VEGF growth factor family
contains 1 CUB domain
proteolytic removal of the N-terminal CUB domain releasing core domain is necessary for unmasking the receptor-binding epitopes of core domain

expressed in heart, pancreas, adrenal gland, ovary > placenta, liver, kidney, prostate, testis, small intestine, spleen, colon
in kidney, expressed by visceral epithelial cells of the glomeruli
widespread expression in medial smooth muscle cells of arteries & arterioles, & smooth muscle cells of vasa rectae in the medullary area
expressed in adventitial connective tissue surrounding the suprarenal artery
expression in normal prostate preferentially in mesenchyme of gland
not detectable in the earliest stages of glomerulogenesis, & not detected in the metanephric blastema or surrounding cortical interstitial cells
in later stages of glomerulogenesis, localized to epithelial cells transitioning from early developing nephrons of the comma- & S-shaped stages to visceral epithelial cells of differentiated glomeruli
in the developing pelvis, expressed at the basement membrane of immature collecting ducts & by presumptive fibroblastic cells in the interstitium

in chronic obstructive nephropathy, persistent expression in glomerular visceral epithelial cells & vascular smooth muscle cells, de novo expression by periglomerular interstitial cells & by some neointimal cells of arteriosclerotic vessels
increased & more profuse in prostate carcinoma than in normal prostate
expressed in many ovarian, lung, renal & brain cancer-derived cell lines