Description and functional validation of human enteroendocrine cell sensors 公告 2024-10-18 14:53:03 Written By Kym Kilbourne Title: Description and Functional Validation of Human enteroendocrine Cell Sensors Research Background and Significance Enteroendocrine cells (EECs) are epithelial cells of the intestine that respond to luminal content by secreting hormones such as glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), which regulate various physiological processes. EECs play a crucial role in regulating metabolism (e.g., appetite, insulin release, intestinal motility) and mucosal immunity. Relatively rare (accounting for approximately 1% of epithelial cells), EECs can be subdivided into five main subtypes, each producing different peptide hormones and/or neurotransmitters. The study of these sensors faces challenges due to the low expression of EECs, interspecies differences, and the existence of multiple EEC subtypes. A deeper understanding of the metabolic sensing proteins of EECs is significant for the development of drugs affecting appetite, intestinal motility, insulin sensitivity, and mucosal immunity. Moreover, drug treatments based on EEC biology currently focus on hormone mimetics (such as derivatives of GLP-1 and GIP), which have shown efficacy in treating diabetes and obesity and are being evaluated for potential applications in other diseases (e.g., metabolic dysfunction-associated fatty liver (MASH), cardiovascular diseases, and neurodegenerative diseases). Research Introduction This study describes a method for differentiating EECs from gastric endocrine cells through pulsed overexpression of NEUROG3, supplementing existing intestinal organoid protocols. The research team constructed a comprehensive transcriptomic map by introducing a fluorescent reporter gene into 14 different endocrine cells with distinct cellular types and regional identities through CRISPR-Cas9-mediated non-homologous end joining. Additionally, the study defined the functionality of 22 individual sensors on different EEC subtypes through functional studies. Research Highlights The discovery of CD200 as a pan-EEC surface marker allows for in-depth transcriptomic analysis from primary human tissues. By generating knockout mutations of 22 receptors in organoids and subjecting the organoids to ligand-induced secretion assays, the research team delineated the role of individual human EEC sensors in hormone secretion, including GLP-1. The study provides a comprehensive single-cell transcriptome map of human tissue EECs and guides the definition of the functionality of 22 individual sensors on various EEC subtypes. Research Results The study successfully differentiated major gastric endocrine cell lines, including EC cells, from human gastric organoids and confirmed the peptide hormones produced by these organoids through proteomic analysis. By constructing a comprehensive transcriptomic map, the research team discovered the expression of many previously described GPCRs in different EEC populations and identified several previously unknown endocrine cell-specific receptor genes. Through single-cell RNA sequencing, the research team generated a dataset comprising 764 endocrine cells and 1314 non-EEC epithelial cells from the GI tract epithelium of the stomach, small intestine, and colon, validating the expression profiles of most receptors acting as sensors. Through functional screening, the research team assessed the functionality of GPCRs in hormone secretion and found multiple receptors controlling the secretion of GLP-1, 5-HT, and ghrelin, including the receptor for black widow toxin α-latrotoxin, ADGRL1/2. Research Significance This study provides new therapeutic strategies for controlling metabolic diseases by targeting the natural metabolic sensors of EECs. The enrichment based on CD200 enables a more in-depth analysis of human EECs under homeostatic and disease conditions. The research results lay the foundation for the development of oral small molecule drugs that activate desired incretin secretion, which may complement or expand the applicability of current incretin-based treatment regimens. The study also proposes the potential role of CD200 as an immune checkpoint on intestinal epithelial cells, providing a new direction for future research on its role in controlling tissue residence or other immune cell activation. Paper Link https://pubmed.ncbi.nlm.nih.gov/39418382/ Kym Kilbourne
Description and functional validation of human enteroendocrine cell sensors 公告 2024-10-18 14:53:03 Written By Kym Kilbourne Title: Description and Functional Validation of Human enteroendocrine Cell Sensors Research Background and Significance Enteroendocrine cells (EECs) are epithelial cells of the intestine that respond to luminal content by secreting hormones such as glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), which regulate various physiological processes. EECs play a crucial role in regulating metabolism (e.g., appetite, insulin release, intestinal motility) and mucosal immunity. Relatively rare (accounting for approximately 1% of epithelial cells), EECs can be subdivided into five main subtypes, each producing different peptide hormones and/or neurotransmitters. The study of these sensors faces challenges due to the low expression of EECs, interspecies differences, and the existence of multiple EEC subtypes. A deeper understanding of the metabolic sensing proteins of EECs is significant for the development of drugs affecting appetite, intestinal motility, insulin sensitivity, and mucosal immunity. Moreover, drug treatments based on EEC biology currently focus on hormone mimetics (such as derivatives of GLP-1 and GIP), which have shown efficacy in treating diabetes and obesity and are being evaluated for potential applications in other diseases (e.g., metabolic dysfunction-associated fatty liver (MASH), cardiovascular diseases, and neurodegenerative diseases). Research Introduction This study describes a method for differentiating EECs from gastric endocrine cells through pulsed overexpression of NEUROG3, supplementing existing intestinal organoid protocols. The research team constructed a comprehensive transcriptomic map by introducing a fluorescent reporter gene into 14 different endocrine cells with distinct cellular types and regional identities through CRISPR-Cas9-mediated non-homologous end joining. Additionally, the study defined the functionality of 22 individual sensors on different EEC subtypes through functional studies. Research Highlights The discovery of CD200 as a pan-EEC surface marker allows for in-depth transcriptomic analysis from primary human tissues. By generating knockout mutations of 22 receptors in organoids and subjecting the organoids to ligand-induced secretion assays, the research team delineated the role of individual human EEC sensors in hormone secretion, including GLP-1. The study provides a comprehensive single-cell transcriptome map of human tissue EECs and guides the definition of the functionality of 22 individual sensors on various EEC subtypes. Research Results The study successfully differentiated major gastric endocrine cell lines, including EC cells, from human gastric organoids and confirmed the peptide hormones produced by these organoids through proteomic analysis. By constructing a comprehensive transcriptomic map, the research team discovered the expression of many previously described GPCRs in different EEC populations and identified several previously unknown endocrine cell-specific receptor genes. Through single-cell RNA sequencing, the research team generated a dataset comprising 764 endocrine cells and 1314 non-EEC epithelial cells from the GI tract epithelium of the stomach, small intestine, and colon, validating the expression profiles of most receptors acting as sensors. Through functional screening, the research team assessed the functionality of GPCRs in hormone secretion and found multiple receptors controlling the secretion of GLP-1, 5-HT, and ghrelin, including the receptor for black widow toxin α-latrotoxin, ADGRL1/2. Research Significance This study provides new therapeutic strategies for controlling metabolic diseases by targeting the natural metabolic sensors of EECs. The enrichment based on CD200 enables a more in-depth analysis of human EECs under homeostatic and disease conditions. The research results lay the foundation for the development of oral small molecule drugs that activate desired incretin secretion, which may complement or expand the applicability of current incretin-based treatment regimens. The study also proposes the potential role of CD200 as an immune checkpoint on intestinal epithelial cells, providing a new direction for future research on its role in controlling tissue residence or other immune cell activation. Paper Link https://pubmed.ncbi.nlm.nih.gov/39418382/ Kym Kilbourne
