Derivation of functional retinal endothelial cells from human pluripotent stem cells for therapeutics and modeling

Retinal microvascular diseases involve a compromised inner blood-retina barrier (iBRB), which remains poorly understood. A renewable source of human iBRB endothelium is thus vital for advancing eye research and treatment development. Here, we differentiated human iPSCs into retinal endothelial cells (iRECs) via the Wnt/{beta}-catenin pathway, namely Norrin/Frizzled4 signaling. These iRECs show genetic, protein, and functional fidelity and unique retinal features. When injected into oxygen-induced retinopathy mice, iRECs integrated into the host vascular network and revascularized the ischemic eye, rescuing the tissue. Within microphysiological models, iRECs form perfusable microvascular networks that mimic the iBRBs morphology and phenotype in both health and diabetic retinopathy conditions while also interacting and organizing physiologically with iPSC-derived retinal pericytes. Our studies establish functional human iRECs and microphysiological iBRB models that facilitate mechanistic studies aimed at identifying therapeutic targets and promoting the revascularization of injured retinas, thereby supporting treatment advancement.