A Human Pluripotent Stem Cell-Based Screen for Smooth Muscle Cell Differentiation and Maturation Identifies Inhibitors of Intimal Hyperplasia

Abstract

Summary: Contractile to synthetic phenotypic switching of smooth muscle cells (SMCs) contributes to stenosis in vascular disease and vascular transplants. To generate more contractile SMCs, we performed a high-throughput differentiation screen using a MYH11-NLuc-tdTomato human embryonic stem cell reporter cell line. We identified RepSox as a factor that promotes differentiation of MYH11-positive cells by promoting NOTCH signaling. RepSox induces SMCs to exhibit a more contractile phenotype than SMCs generated using PDGF-BB and TGF-β1, two factors previously used for SMC differentiation but which also cause intimal hyperplasia. In addition, RepSox inhibited intimal hyperplasia caused by contractile to synthetic phenotypic switching of SMCs in a rat balloon injury model. Thus, in addition to providing more contractile SMCs that could prove useful for constructing artificial blood vessels, this study suggests a strategy for identifying drugs for inhibiting intimal hyperplasia that act by driving contractile differentiation rather than inhibiting proliferation non-specifically. : Thomson, Zhang, and colleagues report a high-throughput screen that can be used for optimization of the fully defined differentiation of contractile smooth muscle cells and identification of intimal hyperplasia inhibitors. Both in vitro and in vivo evidence revealed that RepSox is better than PDGF-BB and TGF-β1 in inducing contractile phenotype of smooth muscle cells and reducing the risk of intimal hyperplasia. Keywords: pluripotent stem cells, contractile smooth muscle cells, differentiation, maturation, RepSox, NOTCH, intima hyperplasia, MYH11-NLuc-tdTomato reporter cell line, high-throughput screen, restenosis