Abstract
Abstract: :
Purpose: DANCE (developmental arteries and neural crest epidermal growth factor-like), a secreted RGD-containing protein, is expressed by neural crest cells and branchial arch mesenchymal cells in development of the heart and great vessels during mouse embryogenesis. It is also expressed during vascular injury and remodeling, and likely plays a role in endothelial adhesion via the integrin receptors. Murine retinal vessels develop post-natally and represent the invasion of mesoderm and potential neural-crest derivatives from the developing hyaloidal system. We asked whether DANCE was present in the retinal vasculature, was higher during development and remodeling, and was absent prior to invasion of the vessels; we also asked what cell types express DANCE. Methods: Whole retinae were isolated from adults, E20 mouse embryos, and PN2 through to PN22 neonatal pups. Total RNA (Trizol method) was converted to cDNA and standard PCR performed for DANCE and beta-actin. Primers for real-time (quantitative) PCR are developed and will be normalized against beta-actin. Adult tissues served as positive and negative controls. In situ hybridization using short T7-generated riboprobe is underway to identify the cell types involved in DANCE expression. Results: At E20, no retinal DANCE expression was detected. However, neonatal mouse retina, days 2 to 22 expressed DANCE. Semi-quantitative PCR suggests this is down-regulated in the adult. Biotinylated sense & anti-sense riboprobe is able to detect DANCE in positive control tissue and is currently being applied to retinal tissue. Conclusions: This study demonstrates the presence of neural crest derivatives in the developing mouse retina, coincident with active angiogenesis. Data from adult and pathological tissues will determine if DANCE is expressed in remodeling retinal vasculature; if so, targeting of DANCE expression may provide additional specificity in the development of novel anti-angiogenic therapies.
Keywords: vascular cells • retina