PC1/3 Deficiency Impacts Pro-opiomelanocortin Processing in Human Embryonic Stem Cell-Derived Hypothalamic Neurons

• Published in: Stem cell reports Vol. 8; no. 2; pp. 264 - 277
• Main Authors: Wang, Liheng, Sui, Lina, Panigrahi, Sunil K., Meece, Kana, Xin, Yurong, Kim, Jinrang, Gromada, Jesper, Doege, Claudia A., Wardlaw, Sharon L., Egli, Dieter, Leibel, Rudolph L.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 14.02.2017; Elsevier
• Subjects: Adrenocorticotropic Hormone - secretion; alpha-MSH - metabolism; Animals; Apoptosis; Cell Differentiation - genetics; Cells, Cultured; CRISPR-Cas Systems; Endoplasmic Reticulum Stress; Gene Expression; Gene Knockdown Techniques; Gene Targeting; hESC; Human Embryonic Stem Cells - cytology; Humans; hypothalamic neurons; Immunohistochemistry; Mice; Mutation; Neurons - cytology; Neurons - metabolism; obesity; PC1/3 deficiency; POMC processing; Pro-Opiomelanocortin - metabolism; Proprotein Convertase 1 - deficiency; Proprotein Convertase 1 - genetics; Proteolysis; Pyramidal Cells - cytology; Pyramidal Cells - metabolism; hypothalamic neurons; POMC processing; PC1/3 deficiency; hESC; obesity
• ISSN: 2213-6711; 2213-6711
• DOI: 10.1016/j.stemcr.2016.12.021

We recently developed a technique for generating hypothalamic neurons from human pluripotent stem cells. Here, as proof of principle, we examine the use of these cells in modeling of a monogenic form of severe obesity: PCSK1 deficiency. The cognate enzyme, PC1/3, processes many prohormones in neuroendocrine and other tissues. We generated PCSK1 (PC1/3)-deficient human embryonic stem cell (hESC) lines using both short hairpin RNA and CRISPR-Cas9, and investigated pro-opiomelanocortin (POMC) processing using hESC-differentiated hypothalamic neurons. The increased levels of unprocessed POMC and the decreased ratios (relative to POMC) of processed POMC-derived peptides in both PCSK1 knockdown and knockout hESC-derived neurons phenocopied POMC processing reported in PC1/3-null mice and PC1/3-deficient patients. PC1/3 deficiency was associated with increased expression of melanocortin receptors and PRCP (prolylcarboxypeptidase, a catabolic enzyme for α-melanocyte stimulating hormone (αMSH)), and reduced adrenocorticotropic hormone secretion. We conclude that the obesity accompanying PCSK1 deficiency may not be primarily due to αMSH deficiency. •Stem cell-derived hypothalamic neurons are used to study human obesity•shRNA and CRISPR-Cas9 were used to generate models of PCSK1 deficiency•PC1/3 deficiency impaired POMC processing in arcuate-like neurons•Adaptive changes occurred in “downstream” POMC processing enzymes Leibel and colleagues use hESC-derived arcuate hypothalamic neurons to examine the neuro-molecular physiology of the hyperphagic obesity that accompanies hypomorphic mutations of PCSK1 in human subjects. They find that reduced proconvertase (PC1/3) activity impairs processing of the propeptide, POMC, and increases the expression of downstream processing enzymes without affecting the final production of αMSH. Decreased levels of the POMC product, ACTH, may contribute to the hyperphagia.