Project description:Microbial density and diversity increase in distal intestinal segments, affecting tissue physiology, metabolism, and function of both the immune and nervous systems. We characterized the influence of the microbiota on murine intrinsic enteric-associated neurons (iEAN). We found that iEAN are functionally adapted to the intestinal segment they occupy, with a stronger microbiota influence on ileal and colonic neurons. Chemogenetic characterization of microbiota-influenced iEAN identified a subset of viscerofugal CART+ neurons, enriched in the ileum and colon, able to modulate feeding and glucose metabolism. Retro- and anterograde tracing revealed that CART+ viscerofugal neurons send axons to the prevertebral ganglia and are poly-synaptically connected to the liver and pancreas. Microbiota depletion led to NLRP6 and Caspase 11-dependent loss of CART+ neurons, and impaired liver-mediated gluconeogenesis. Our results demonstrate a region-specific adaptation of enteric neurons and indicate that iEAN subsets are capable of regulating blood glucose levels independently from the central nervous system.
Project description:We showed that iPSC-derived GD2-CART therapy for SCLC was more effective than peripheral blood-derived GD2-CART. Here, we investigated the molecular difference between iPSC-derived GD2-CARTs and peripheral blood-derived GD2-CARTs.
Project description:Cocaine and amphetamine-regulated transcript (CART) is expressed in pancreatic islet cells and neuronal elements. We have previously established insulinotropic actions of CART in human and rodent islets. The receptor for CART in the pancreatic beta cells is unidentified. We used RNA sequencing of Cartpt knock down (KD) INS-1 832/13 cells and identified GPR162 as the most Cartpt-regulated receptor. We therefore tested if GPR162 mediates the effects of CART in beta cells. Binding of CART to GPR162 was established using proximity ligation assay, radioactive binding and co-immunoprecipitation, and KD of Gpr162 mRNA caused reduced binding. Gpr162 KD cells had blunted CARTp-induced exocytosis, and reduced CARTp-induced insulin secretion. Furthermore, we identified a hitherto undescribed GPR162-dependent role of CART as a regulator of cytoskeletal arrangement. Thus, our findings provide mechanistic insight into the effect of CART on insulin secretion and show that GPR162 is the CART receptor in beta cells.
Project description:Cocaine and amphetamine-regulated transcript (CART) is expressed in pancreatic islet cells and neuronal elements. We have previously established insulinotropic actions of CART in human and rodent islets. The receptor for CART in the pancreatic beta cells is unidentified. We used RNA sequencing of Cartpt knock down (KD) INS-1 832/13 cells and identified GPR162 as the most Cartpt-regulated receptor. We therefore tested if GPR162 mediates the effects of CART in beta cells. Binding of CART to GPR162 was established using proximity ligation assay, radioactive binding and co-immunoprecipitation, and KD of Gpr162 mRNA caused reduced binding. Gpr162 KD cells had blunted CARTp-induced exocytosis, and reduced CARTp-induced insulin secretion. Furthermore, we identified a hitherto undescribed GPR162-dependent role of CART as a regulator of cytoskeletal arrangement. Thus, our findings provide mechanistic insight into the effect of CART on insulin secretion and show that GPR162 is the CART receptor in beta cells.
Project description:Identification of cellular functions and signalling pathways of intestinal epithelial cells modulated by enteric glial cells Keywords: Transcriptome regulation Two-condition experiment (intestinal epithelial cells cultured in absence or in presence of enteric glial cells) with 3 time points (t=0, 8 and 24h). 4 Biological replicates/condition. Every replicate was hybridized against a reference pool composed by a mix of the 4 replicates of t=0 condition in equal quantity.
Project description:Identification of cellular functions and signalling pathways of intestinal epithelial cells modulated by enteric glial cells Keywords: Transcriptome regulation
Project description:BACKGROUND Enteric glia contribute to the pathophysiology of various intestinal immune-driven diseases, such as postoperative ileus (POI), a motility disorder and common complication after abdominal surgery. Enteric gliosis of the intestinal muscularis externa (ME) has been identified as part of POI development. However, the glia-restricted responses and activation mechanisms are poorly understood. The sympathetic nervous system becomes rapidly activated by abdominal surgery. It modulates intestinal immunity, innervates all intestinal layers, and directly interfaces with enteric glia. We hypothesized that sympathetic innervation controls enteric glia reactivity in response to surgical trauma. METHODS Sox10iCreERT2/Rpl22HA/+ mice were subjected to a mouse model of laparotomy or intestinal manipulation to induce POI. Histological, protein, and transcriptomic analyses were performed to analyze glia-specific responses. Interactions between the sympathetic nervous system and enteric glia were studied in mice chemically depleted of TH+ sympathetic neurons and glial-restricted Sox10iCreERT2/JellyOPfl/+/Rpl22HA/+ mice, allowing optogenetic stimulation of β-adrenergic downstream signaling and glial-specific transcriptome analyses. A laparotomy model was used to study the effect of sympathetic signaling on enteric glia in the absence of intestinal manipulation. Mechanistic studies included adrenergic receptor expression profiling in vivo and in vitro and adrenergic agonism treatments of primary enteric glial cell cultures to elucidate the role of sympathetic signaling in acute enteric gliosis and POI. RESULTS With ~4000 differentially expressed genes, the most substantial enteric glia response occurs early after intestinal manipulation. During POI, enteric glia switch into a reactive state and continuously shape their microenvironment by releasing inflammatory and migratory factors. Sympathetic denervation reduced the inflammatory response of enteric glia in the early postoperative phase. Optogenetic and pharmacological stimulation of β-adrenergic downstream signaling triggered enteric glia reactivity. Finally, distinct adrenergic agonists revealed β-1/2 adrenoceptors as the molecular targets of sympathetic–driven enteric glial reactivity. CONCLUSIONS Enteric glia act as early responders during post-traumatic intestinal injury and inflammation. Intact sympathetic innervation and active β-adrenergic receptor signaling in enteric glia is a trigger of the immediate glial postoperative inflammatory response. With immune-activating cues originating from the sympathetic nervous system as early as the initial surgical incision, adrenergic signaling in enteric glia presents a promising target for preventing POI development.
Project description:Primary objectives: Characterization of the macrophage population subset that is modulated by enteric neurons
Primary endpoints: Characterization of the macrophage population subset that is modulated by enteric neurons via RNA sequencing