Functional engineering of human iPSC‐derived parasympathetic neurons enhances responsiveness to gastrointestinal hormones

• Published in: FEBS open bio 2024-01, Vol.14 (1), p.63-78
• Main Authors: Akagi, Yuka, Takayama, Yuzo, Nihashi, Yuma, Yamashita, Azusa, Yoshida, Risa, Miyamoto, Yasuhisa, Kida, Yasuyuki S.
• Format: Article
• Language: English
• Subjects: Animal welfare; Animals; Brain; Brain-derived neurotrophic factor; brain–gut axis; Calcium imaging; Cell Differentiation; Cell Signalling; Cholecystokinin; Digestive system; Drug development; gastrointestinal hormone; Gastrointestinal Hormones - metabolism; Gastrointestinal tract; Gastrointestinal, Hepatic and Pancreatic Physiology; Gene expression; Hormones; Humans; induced pluripotent stem cells; Induced Pluripotent Stem Cells - metabolism; Inhibitory postsynaptic potentials; Kinases; mRNA stability; Neuroimaging; Neurons; Paracrine signalling; Parasympathetic nervous system; Peripheral nerves; Plasmids; Pluripotency; Serotonin; Signal Transduction; Stem Cells; Vagus nerve
• ISSN: 2211-5463; 2211-5463
• DOI: 10.1002/2211-5463.13741

Food‐derived biological signals are transmitted to the brain via peripheral nerves through the paracrine activity of gastrointestinal (GI) hormones. The signal transduction circuit of the brain–gut axis has been analyzed in animals; however, species‐related differences and animal welfare concerns necessitate investigation using in vitro human experimental models. Here, we focused on the receptors of five GI hormones (CCK, GLP1, GLP2, PYY, and serotonin (5‐HT)), and established human induced pluripotent stem cell (iPSC) lines that functionally expressed each receptor. Compared to the original iPSCs, iPSCs expressing one of the receptors did not show any differences in global mRNA expression, genomic stability, or differentiation capacities of the three germ layers. We induced parasympathetic neurons from these established iPSC lines to assess vagus nerve activity. We generated GI hormone receptor‐expressing neurons (CCKAR, GLP1R, and NPY2R‐neuron) and tested their responsiveness to each ligand using Ca2+ imaging and microelectrode array recording. GI hormone receptor‐expressing neurons (GLP2R and HTR3A) were generated directly by gene induction into iPSC‐derived peripheral nerve progenitors. These receptor‐expressing neurons promise to contribute to a better understanding of how the body responds to GI hormones via the brain–gut axis, aid in drug development, and offer an alternative to animal studies. Gastrointestinal (GI) hormones transmit food‐derived signals to the brain via peripheral nerves. To address the lack of in vitro neuronal models responsive to GI hormones, we generated parasympathetic neurons from human induced pluripotent stem cell lines expressing five GI hormone receptors. These neurons have potential to provide in vitro models to reduce animal experiments and enhance our understanding of signal transmission.