Arboleda-Velasquez, JosephPrimo, VincentGraham, MarkJames, AlexandraManent, JanD'Amore, Patricia2018-02-232014Arboleda-Velasquez, Joseph F., Vincent Primo, Mark Graham, Alexandra James, Jan Manent, and Patricia A. D’Amore. 2014. “Notch Signaling Functions in Retinal Pericyte Survival.” Investigative Opthalmology & Visual Science 55 (8) (August 20): 5191. doi:10.1167/iovs.14-14046.1552-5783http://nrs.harvard.edu/urn-3:HUL.InstRepos:34865296Purpose.: Pericytes, the vascular cells that constitute the outer layer of capillaries, have been shown to have a crucial role in vascular development and stability. Loss of pericytes precedes endothelial cell dysfunction and vascular degeneration in small-vessel diseases, including diabetic retinopathy. Despite their clinical relevance, the cellular pathways controlling survival of retinal pericytes remain largely uncharacterized. Therefore, we investigated the role of Notch signaling, a master regulator of cell fate decisions, in retinal pericyte survival. Methods.: A coculture system of ligand-dependent Notch signaling was developed using primary cultured retinal pericytes and a mesenchymal cell line derived from an inducible mouse model expressing the Delta-like 1 Notch ligand. This model was used to examine the effect of Notch activity on pericyte survival using quantitative PCR (qPCR) and a light-induced cell death assay. The effect of Notch gain- and loss-of-function was analyzed in monocultures of retinal pericytes using antibody arrays to interrogate the expression of apoptosis-related proteins. Results.: Primary cultured retinal pericytes differentially expressed key molecules of the Notch pathway and displayed strong expression of canonical Notch/RBPJK (recombination signal-binding protein 1 for J-kappa) downstream targets. A gene expression screen using gain- and loss-of-function approaches identified genes relevant to cell survival as downstream targets of Notch activity in retinal pericytes. Ligand-mediated Notch activity protected retinal pericytes from light-induced cell death. Conclusions.: Our results have identified signature genes downstream of Notch activity in retinal pericytes and suggest that tight regulation of Notch signaling is crucial for pericyte survival.en-USdiabetic retinopathysurvivalnotch signalingcoculturepericytesmall-vesselJournal Article2017-06-2320142018-02-2310.1167/iovs.14-14046