An RNAi Screen Reveals an Essential Role for HIPK4 in Human Skin Epithelial Differentiation from iPSCs

• Published in: Stem cell reports 2017-10, Vol.9 (4), p.1234-1245
• Main Authors: Larribère, Lionel, Galach, Marta, Novak, Daniel, Arévalo, Karla, Volz, Hans Christian, Stark, Hans-Jürgen, Boukamp, Petra, Boutros, Michael, Utikal, Jochen
• Format: Article
• Language: English
• Subjects: Cell Differentiation - genetics; Cell Line; Cells, Cultured; development; differentiation; Enzyme Activation; Epithelial Cells - cytology; Epithelial Cells - metabolism; epithelium; Gene Silencing; High-Throughput Screening Assays; HIPK4; Humans; Induced Pluripotent Stem Cells - cytology; Induced Pluripotent Stem Cells - metabolism; iPSC; keratinocytes; Keratinocytes - cytology; Keratinocytes - metabolism; Organ Culture Techniques; organotypic culture; Protein-Serine-Threonine Kinases - genetics; RNA Interference; RNAi screen; skin; stem cell
• ISSN: 2213-6711; 2213-6711
• DOI: 10.1016/j.stemcr.2017.08.023

Molecular mechanisms responsible for the development of human skin epithelial cells are incompletely understood. As a consequence, the efficiency to establish a pure skin epithelial cell population from human induced pluripotent stem cells (hiPSCs) remains poor. Using an approach including RNAi and high-throughput imaging of early epithelial cells, we identified candidate kinases involved in their differentiation from hiPSCs. Among these, we found HIPK4 to be an important inhibitor of this process. Indeed, its silencing increased the amount of generated skin epithelial precursors at an early time point, increased the amount of generated keratinocytes at a later time point, and improved growth and differentiation of organotypic cultures, allowing for the formation of a denser basal layer and stratification with the expression of several keratins. Our data bring substantial input regarding regulation of human skin epithelial differentiation and for improving differentiation protocols from pluripotent stem cells. •High-throughput RNAi screen setup during human skin epithelial differentiation•Identification of HIPK4 as a crucial blocker of human skin epithelial differentiation•Improvement of human organotypic epithelial cultures after HIPK4 silencing In this article, Larribère and colleagues establish a high-throughput RNAi screen on induced pluripotent stem cell-derived epithelial cells. This screen led to the identification of HIPK4 as a crucial blocker of human skin epithelial differentiation. Indeed, HIPK4 silencing increased the amount of early generated skin epithelial precursors, increased the amount of generated keratinocytes, and improved the differentiation of organotypic cultures.