Effect of a high fat diet on gene expression in enteroendocrine cells of the mouse jejunum
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ABSTRACT: To identify the genes differentially expressed in jejunal enteroendocrine cells (EECs) under a high fat diet we purified EEC (eYFP+) and non-EEC(eYFP-) using FACS from jejunal villi of Neurog3eYFP/+ mice (Mellitzer et al, Mol. Endo 2004) fed with a normal chow or high fat diet (HFD). In Neurog3eYFP/+ mice enteroendocrine progenitors and their descendants are labeled with eYFP. We then purified the RNA and perfomed gene exspression profiling using RNAseq.
Project description:Enteroendocrine cells (EECs) sense intestinal content and release hormones to regulate gastrointestinal activity and systemic metabolism and food intake. Little is known about the molecular make-up of human EEC subtypes and the regulated secretion of individual hormones. Here we describe an organoid-based platform for functional studies of human EECs. EEC formation is induced in vitro by transient expression of NEUROG3. A set of gut organoids was engineered in which the major hormones are fluorescently tagged. A single-cell mRNA atlas was generated for the different EEC subtypes, and their secreted products were recorded by mass-spectrometry. We note key differences with murine EECs, including in hormones, sensory receptors and transcription factors. Notably, several novel hormone-like molecules were identified. Inter-EEC communication is exemplified by Secretin-induced GLP-1 secretion. Indeed, individual EEC subtypes carry receptors for various EEC hormones. This study provides a rich resource to study human EEC development and function.
Project description:To analyse the peptidomics of mouse enteroendocrine cells (EECs) and human gastrointestinal (GI) tissue and identify novel gut derived peptides. High resolution nano-flow liquid chromatography mass spectrometry (LCMS) was performed on (i) flow-cytometry purified NeuroD1 positive cells from mouse and homogenised human intestinal biopsies, (ii) supernatants from primary murine intestinal cultures, (iii) intestinal homogenates from mice fed high fat diet. Candidate bioactive peptides were selected on the basis of species conservation, high expression/biosynthesis in EECs and evidence of regulated secretion in vitro. Candidate novel gut-derived peptides were chronically administered to mice to assess effects on food intake and glucose tolerance.
Project description:Background and aims: Enteroendocrine cells (EECs) and their hormones are essential regulators of whole-body energy homeostasis. EECs sense luminal nutrients and microbial metabolites and subsequently secrete a variety of hormones acting locally or at distance. Impaired development of EECs during embryogenesis is life-threatening in newborn mice and humans due to compromised nutrient absorption. However, the physiological importance of the EEC system in adult mice has not been directedly studied. Herein, we aimed to determine the long-term consequences of a total loss of EECs in healthy adults on energy metabolism, intestinal transcriptome and microbiota. Methods: We depleted intestinal EECs by tamoxifen treatment of adult Neurog3fl/fl; Villin-CreERT2 male mice. We studied intestinal cell differentiation, food efficiency, lipid absorption, microbiota composition, fecal metabolites and transcriptomic responses in the proximal and distal small intestine of mice lacking EECs. We also determined the high-fat diet induced transcriptomic changes in sorted Neurog3eYFP/+EECs. Results: Induction of EECs deficiency in adults is not life-threatening unless fed with a high-fat diet. Under a standard chow diet, mice lose 10% of weight due to impaired food efficiency. Blood concentrations of cholesterol, triglycerides, and free fatty acids are reduced and lipid absorption is impaired and delayed to the distal small intestine. Genes controlling lipogenesis, carbohydrate metabolism and neoglucogenesis are upregulated. Microbiota composition is rapidly altered after ECCs depletion and characterized by decreased -diversity. Bacteroides and Lactobacillus were progressively enriched while Lachnospiraceae declined without impacting fecal short chain fatty acid concentrations. Conclusions: EECs are dispensable for survival in adult male mice under a standard chow diet. The absence of EECs impairs intestinal lipid absorption leading to transcriptomic and metabolic adaptations and remodeling of the gut microbiota.
Project description:Background and aims: Enteroendocrine cells (EECs) and their hormones are essential regulators of whole-body energy homeostasis. EECs sense luminal nutrients and microbial metabolites and subsequently secrete a variety of hormones acting locally or at distance. Impaired development of EECs during embryogenesis is life-threatening in newborn mice and humans due to compromised nutrient absorption. However, the physiological importance of the EEC system in adult mice has not been directedly studied. Herein, we aimed to determine the long-term consequences of a total loss of EECs in healthy adults on energy metabolism, intestinal transcriptome and microbiota. Methods: We depleted intestinal EECs by tamoxifen treatment of adult Neurog3fl/fl; Villin-CreERT2 male mice. We studied intestinal cell differentiation, food efficiency, lipid absorption, microbiota composition, fecal metabolites and transcriptomic responses in the proximal and distal small intestine of mice lacking EECs. We also determined the high-fat diet induced transcriptomic changes in sorted Neurog3eYFP/+EECs. Results: Induction of EECs deficiency in adults is not life-threatening unless fed with a high-fat diet. Under a standard chow diet, mice lose 10% of weight due to impaired food efficiency. Blood concentrations of cholesterol, triglycerides, and free fatty acids are reduced and lipid absorption is impaired and delayed to the distal small intestine. Genes controlling lipogenesis, carbohydrate metabolism and neoglucogenesis are upregulated. Microbiota composition is rapidly altered after ECCs depletion and characterized by decreased alpha-diversity. Bacteroides and Lactobacillus were progressively enriched while Lachnospiraceae declined without impacting fecal short chain fatty acid concentrations. Conclusions: EECs are dispensable for survival in adult male mice under a standard chow diet. The absence of EECs impairs intestinal lipid absorption leading to transcriptomic and metabolic adaptations and remodeling of the gut microbiota.
Project description:We purified two populations of human jejunal enteroendocrine cells (GLP1+ and GLP1-) by FACS and identified transcripts enriched in endocrine cell lineages.
Project description:Enteroendocrine cells (EECs) are hormone-producing cells residing in the epithelium of stomach, small intestine (SI) and colon. EECs regulate various aspects of metabolic activity including insulin levels, satiety, gastrointestinal secretion and motility. The generation of different EEC lineages of the SI is incompletely understood. We now report a TFome-wide CRISPR knockout screen in adult human intestinal organoids to identify dominant transcription factors controlling EEC differentiation. ZNF800 is discovered as a master repressor for endocrine lineage commitment, which particularly restricts enterochromaffin cell differentiation by directly controlling an endocrine TF network centered on PAX4. Thus, organoid models allow unbiased functional SCRISPR screens for genes that program cell differentiation.
Project description:Enteroendocrine cells (EECs) are hormone-producing cells residing in the epithelium of stomach, small intestine (SI) and colon. EECs regulate various aspects of metabolic activity including insulin levels, satiety, gastrointestinal secretion and motility. The generation of different EEC lineages of the SI is incompletely understood. We now report a TFome-wide CRISPR knockout screen in adult human intestinal organoids to identify dominant transcription factors controlling EEC differentiation. ZNF800 is discovered as a master repressor for endocrine lineage commitment, which particularly restricts enterochromaffin cell differentiation by directly controlling an endocrine TF network centered on PAX4. Thus, organoid models allow unbiased functional SCRISPR screens for genes that program cell differentiation.
Project description:Enteroendocrine cells (EECs) are hormone-producing cells residing in the epithelium of stomach, small intestine (SI) and colon. EECs regulate various aspects of metabolic activity including insulin levels, satiety, gastrointestinal secretion and motility. The generation of different EEC lineages of the SI is incompletely understood. We now report a TFome-wide CRISPR knockout screen in adult human intestinal organoids to identify dominant transcription factors controlling EEC differentiation. ZNF800 is discovered as a master repressor for endocrine lineage commitment, which particularly restricts enterochromaffin cell differentiation by directly controlling an endocrine TF network centered on PAX4. Thus, organoid models allow unbiased functional SCRISPR screens for genes that program cell differentiation.
Project description:Enteroendocrine cells (EECs) secrete serotonin (enterochromaffin [EC] cells) or specific peptide hormones (non-EC cells) that serve vital metabolic functions. The basis for terminal EEC diversity remains obscure. By forcing activity of the transcription factor (TF) NEUROG3 in 2D cultures of human intestinal stem cells, we replicated physiologic EEC differentiation and examined transcriptional and cis-regulatory dynamics that culminate in discrete cell types. Abundant EEC precursors expressed stage-specific genes and TFs. Before expressing pre-terminal NEUROD1, post-mitotic precursors oscillated between transcriptionally distinct ASCL1+ and HES6hi cell states. Loss of either factor accelerated EEC differentiation substantially and disrupted EEC individuality; ASCL1 or NEUROD1 deficiency had opposing consequences on EC and non-EC cell features. These TFs mainly bind cis-elements that are accessible in undifferentiated stem cells, and they tailor subsequent expression of TF combinations that underlie discrete EEC identities. Thus, early TF oscillations retard EEC maturation to enable accurate diversity within a medically important cell lineage.
Project description:Lgr5+ adult intestinal stem cells are highly proliferative throughout life. Single Lgr5+ stem cells can be cultured into 3D epithelial organoids containing all cell types at nearnormal ratios. Culture conditions to generate the main cell types have been established previously, but signals inducing the various types of enteroendocrine cells (EECs) have remained elusive. Here we generate quiescent Lgr5+ stem cells in vitro by inhibition of the EGF-receptor (EGFR) and mitogen-associated protein kinase (MAPK) signaling pathways in organoids, a state that can be readily reversed. Quiescent Lgr5+ stem cells gain a distinct molecular signature, biased towards EEC differentiation. Indeed, combined inhibition of Wnt, Notch and MAPK pathways efficiently generates a diversity of EEC subtypes in vitro. Our observations uncouple Wnt-dependent stem cell maintenance from EGF-dependent proliferation and cell fate choice, and provide an in vitro approach for the study of the elusive EECs.