MESP1 knock-down in human iPSC attenuates early vascular progenitor cell differentiation after completed primitive streak specification

Dev Biol. 2019 Jan 1;445(1):1-7. doi: 10.1016/j.ydbio.2018.10.020. Epub 2018 Oct 31.


MESP1 is a key transcription factor in development of early cardiovascular tissue and it is required for induction of the cardiomyocyte (CM) gene expression program, but its role in vascular development is unclear. Here, we used inducible CRISPRi knock-down of MESP1 to analyze the molecular processes of the early differentiation stages of human induced pluripotent stem cells into mesoderm and subsequently vascular progenitor cells. We found that expression of the mesodermal marker, BRACHYURY (encoded by T) was unaffected in MESP1 knock-down cells as compared to wild type cells suggesting timely movement through the primitive streak whereas another mesodermal marker MIXL1 was slightly, but significantly decreased. In contrast, the expression of the vascular cell surface marker KDR was decreased and CD31 and CD34 expression were substantially reduced in MESP1 knock-down cells supporting inhibition or delay of vascular specification. In addition, mRNA microarray data revealed several other altered gene expressions including the EMT regulating transcription factors SNAI1 and TWIST1, which were both significantly decreased indicating that MESP1 knock-down cells are less likely to undergo EMT during vascular progenitor differentiation. Our study demonstrates that while leaving primitive streak markers unaffected, MESP1 expression is required for timely vascular progenitor specification. Thus, MESP1 expression is essential for the molecular features of early CM, EC and VSMC lineage specification.

Keywords: CRISPR; Differentiation; IPSC; MESP1; Vascular progenitor.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Basic Helix-Loop-Helix Transcription Factors / genetics
  • Basic Helix-Loop-Helix Transcription Factors / metabolism*
  • Cell Differentiation / physiology
  • Cell Lineage
  • Embryonic Stem Cells / cytology
  • Endothelial Progenitor Cells / cytology
  • Endothelial Progenitor Cells / metabolism
  • Fetal Proteins / metabolism
  • Gene Expression Regulation, Developmental / genetics
  • Helix-Loop-Helix Motifs / physiology
  • Homeodomain Proteins / metabolism
  • Humans
  • Induced Pluripotent Stem Cells / cytology
  • Induced Pluripotent Stem Cells / metabolism*
  • Mesoderm / metabolism
  • Myocardium / metabolism
  • Myocytes, Cardiac / metabolism
  • Primitive Streak / cytology
  • Primitive Streak / metabolism*
  • T-Box Domain Proteins / metabolism
  • Transcription Factors / metabolism


  • Basic Helix-Loop-Helix Transcription Factors
  • Fetal Proteins
  • Homeodomain Proteins
  • MESP1 protein, human
  • MIXL1 protein, human
  • T-Box Domain Proteins
  • Transcription Factors
  • Brachyury protein