Modeling corticotroph deficiency with pituitary organoids supports the functional role of <i>NFKB2</i> in human pituitary differentiation.

Abstract

Deficient Anterior pituitary with common Variable Immune Deficiency (DAVID) syndrome results from <i>NFKB2</i> heterozygous mutations, causing adrenocorticotropic hormone deficiency (ACTHD) and primary hypogammaglobulinemia. While NFKB signaling plays a crucial role in the immune system, its connection to endocrine symptoms is unclear. We established a human disease model to investigate the role of <i>NFKB2</i> in pituitary development by creating pituitary organoids from CRISPR/Cas9-edited human induced pluripotent stem cells (hiPSCs). Introducing homozygous <i>TBX19^K146R/K146R</i> missense pathogenic variant in hiPSC, an allele found in congenital isolated ACTHD, led to a strong reduction of corticotrophs number in pituitary organoids. Then, we characterized the development of organoids harboring <i>NFKB2^D865G/D865G</i> mutations found in DAVID patients. <i>NFKB2^D865G/D865G</i> mutation acted at different levels of development with mutant organoids displaying changes in the expression of genes involved on pituitary progenitor generation (<i>HESX1</i>, <i>PITX1</i>, <i>LHX3</i>), hypothalamic secreted factors (<i>BMP4, FGF8, FGF10</i>), epithelial-to-mesenchymal transition, lineage precursors development (<i>TBX19</i>, <i>POU1F1</i>) and corticotrophs terminal differentiation (<i>PCSK1, POMC</i>), and showed drastic reduction in the number of corticotrophs. Our results provide strong evidence for the direct role of <i>NFKB2</i> mutations in the endocrine phenotype observed in patients leading to a new classification of a <i>NFKB2</i> variant of previously unknown clinical significance as pathogenic in pituitary development.