Supplementary Components1. O-GlcNAcylation, O-GlcNAc transferase (OGT) suppresses expression of the lineage-specifying transcription factor Neurogenin 3 and, thus, L cell differentiation from enteroendocrine progenitors. Intestinal epithelial ablation of OGT in mice not only causes L cell hyperplasia and increased secretion of glucagon-like peptide 1 (GLP-1) but also disrupts gut microbial compositions, which notably contributes to decreased weight gain and improved NADP glycemic control. Our results identify intestinal epithelial O-GlcNAc signaling as a brake on L cell development and function in response to nutritional and microbial cues. Graphical Abstract In Brief Zhao et al. identify OGT in intestinal epithelial cells as a molecular brake on L cell advancement and function in response to dietary and microbial cues. OGT inhibits gene enteroendocrine and transcription differentiation via FOXO1 O-GlcNAcylation. Microbiota-derived SCFAs travel epithelial O-GlcNAcylation, which influences gut microbiota to regulate systemic metabolism further. Intro Enteroendocrine cells (EECs) are specific epithelial cells from the gastrointestinal system that form the biggest endocrine system in the torso. By sensing luminal indicators, EECs make and magic formula human hormones and neurotransmitters to modulate a number of metabolic features locally and systemically, such as for example gut motility, nutrient absorption and intake, glucose rate of metabolism, lipid homeostasis, and energy stability (Mellitzer et al., 2010; Moran-Ramos et al., 2012; Holst, 2013; Reimann and Gribble, 2016). Studies claim that problems in EEC function and gut hormone secretion are connected with human being weight problems and diabetes (Toft-Nielsen et al., 2001; Vilsb?ll et al., 2001; Faerch et al., 2015). Consequently, gut human hormones are excellent restorative applicants for treatment of metabolic illnesses. Agonists from the glucagonlike peptide 1 (GLP-1) receptor and inhibitors of dipeptidyl peptidase-4 (DPP4), which inactivates GLP-1, are utilized for effective glycemic control in diabetics broadly, with demonstrated great things about weight reduction and cardioprotection aswell (Cantini et al., 2016; Drucker, 2016). The gut hormone reactions to bariatric methods have been suggested to be always a system for weight reduction NADP and improvement in blood sugar metabolism after medical procedures (Hutch and Sandoval, 2017). Furthermore, dual and triple gut hormone receptor agonists are believed next-generation therapies for metabolic illnesses (Troke et al., 2014; Brandt et al., 2018). Despite intensive software of enteroendocrine human hormones in the center, the pathophysiological rules of EEC advancement and function can be realized incompletely, and direct methods to modulate EEC differentiation are largely lacking still. Typically, EECs are categorized based on the human hormones they make: L cells (GLP-1 and peptide YY [PYY]), K cells (gastric inhibitory polypeptide [GIP]), I cells (cholecystokinin [CCK]), D cells (somatostatin [SST]), S cells (secretin [SCT]), and enterochromaffin (EC) PMCH cells (serotonin [5-HT]) (Latorre et al., 2016). Nevertheless, considerable data from latest research using transcriptional profiling, transgenic reporter lines, immunohistochemistry, and especially single-cell RNA sequencing possess demonstrated that there surely is significant coexpression of human hormones and crossover between EEC subtypes (Egerod et al., 2012; Habib et al., 2012; Gribble and Reimann, 2016; Haber et al., 2017; Gehart et al., 2019). EECs differentiate from the normal LGR5+ pluripotent stem cells in the bottom from the crypt area (Cheng and Leblond, 1974; Barker et al., 2007). Three fundamental helix-loop-helix transcription elements, including ATOH1, Neurogenin 3 (encoded from the gene), and NeuroD1, are indicated sequentially and function in cascades for EEC differentiation (Schonhoff et al., 2004a). ATOH1 is crucial for advancement of most three secretory cell types (Yang et al., 2001; Shroyer et al., 2007), whereas Neurogenin 3 can be specific for dedication and differentiation into EECs (Jenny et NADP al., 2002; Lee et al.,2002; Mellitzer et al., 2010). NeuroD1, a downstream focus on of Neurogenin 3, can be very important to S and I cell differentiation (Mutoh et al., 1997; Naya et al., 1997). Furthermore, PAX4 and PAX6 have already been proven to control L, K, D, and EC cell differentiation (Larsson et al., 1998). Recently, novel general and lineage-specific regulators of EEC differentiation have also been identified by real-time single-cell transcriptional profiling (Gehart et al., 2019). Nonetheless, the upstream molecular mechanisms fine-tuning the transcriptional machinery for EEC development have not been fully elucidated. Within the last three decades, it was discovered that thousands NADP of cytoplasmic and nuclear proteins are modified by a single O-linked -N-acetylglucosamine (O-GlcNAc) moiety at serine or threonine residues, termed O-GlcNAcylation (Torres and Hart, 1984; Hart et al., 2007, 2011). O-GlcNAcylation is radically different from other types of glycosylation and, analogous to phosphorylation, plays a central role in signaling pathways relevant to normal cell physiology and chronic human diseases, including cardiovascular disease, diabetes, neurodegeneration, and cancer (Bond and Hanover, 2013;.