Reconstitution of human adrenocortical specification and steroidogenesis using induced pluripotent stem cells.

The mechanisms leading to adrenal cortex development and steroid synthesis in humans remain poorly understood due to the paucity of model systems. Herein, we recapitulate human fetal adrenal cortex specification processes through stepwise induction of human-induced pluripotent stem cells through posterior intermediate mesoderm-like and adrenocortical progenitor-like states to ultimately generate fetal zone adrenal-cortex-like cells (FZLCs), as evidenced by histomorphological, ultrastructural, and transcriptome features and adrenocorticotropic hormone (ACTH)-independent Δ5 steroid biosynthesis. Furthermore, FZLC generation is promoted by SHH and inhibited by NOTCH, ACTIVIN, and WNT signaling, and steroid synthesis is amplified by ACTH/PKA signaling and blocked by inhibitors of Δ5 steroid synthesis enzymes. Finally, NR5A1 promotes FZLC survival and steroidogenesis. Together, these findings provide a framework for understanding and reconstituting human adrenocortical development in vitro , paving the way for cell-based therapies of adrenal insufficiency. [Display omitted] • Fetal zone adrenal-cortex-like cells are induced from human pluripotent stem cells • Induction is ACTH independent and inhibited by NOTCH, ACTIVIN, and WNT signaling • Robust Δ5 adrenal steroid biosynthesis is ACTH/PKA-responsive • NR5A1 is essential for survival and steroidogenesis of human fetal adrenal cortex Human adrenocortical development remains enigmatic due to the lack of appropriate models. Adrenocortical lineages established from human pluripotent stem cells by Sakata et al. recapitulate functional, histomorphologic, and transcriptomic features found in vivo , supporting their use for pharmacologic, genetic, and epigenetic interrogation of human adrenocortical development and testing of cell-based therapies. [ABSTRACT FROM AUTHOR]