SignificanceBlood vessels in the central nervous system possess unique barrier properties that prevent infiltration of foreign substances and allow for precise delivery of ions, molecules, and immune cells into neural networks. Barrier breakdown is associated with a host of retinal and neurological disorders but few BRB/BBB-enhancing therapies have been developed. To identify novel barrier-inducing factors, we genetically engineered a transcriptional reporter cell line with CRISPR technology for compound library screening. Using this approach, we identified compounds, including a TGF-β receptor inhibitor, RepSox, which functions in vitro to increase barrier resistance in human primary and stem cell-derived endothelial cell lines. These data may inform future therapies for BRB/BBB disorders and retinal/neurological diseases.