The involvement of SPARC and HEVIN in angiogenesis in the retina.

Abstract

Angiogenesis is the formation of new blood vessels from existing ones and is regulated by a balance of pro- and anti-angiogenic factors such as vascular endothelial growth factors and platelet-derived growth factor. An imbalance will result in the activation of unwanted angiogenesis which can occur in a range of ocular diseases such as age-related macular degeneration and diabetic retinopathy. Matricellular proteins like SPARC and HEVIN are gaining interest for their role in the regulation of cellular functions as well as angiogenesis. The role of SPARC in angiogenesis has been studied extensively, but not in relation to the retinal pigment epithelium in retina. HEVIN, a homologue of SPARC, may regulate angiogenesis in a similar manner. To better understand the mechanisms underlying SPARC and HEVIN mediated inhibition of angiogenesis in the retina, we carried out a RT2 Profiler PCR Array to profile the expression of 84 genes related to mouse angiogenesis signaling pathway with RPE cells isolated from mice depleted with SPARC and HEVIN. The findings of our study revealed that both SPARC and HEVIN regulate the expression of collagen, VEGFs, PDGF, MMP2 and MMP9 in angiogenesis but they may not necessary function in a similar mechanism.