Project description:Enteric nervous system is involved in the regulation of intestinal inflammation. We developped mouse primary cultures of enteric nervous system to study impact of LPS, as pro-inflammatory mediator, and of the pro-drug 6-mercaptopurine on enteric inflammatory pathways We used microarrays to detail the global programme of gene expression underlying enteric neuro-inflammation and identified classes of up-regulated genes during this process.
Project description:Profiling of transcriptional changes in rat astrocytes when co-cultured with neurons: comparison of astrocytes cultured alone with astrocytes co-cultured with mouse hippocampal neurons. Co-cultured astrocytes are isolated using cold jet, a novel tool for these neuron-glia cultures. Over the last decade, the importance of astrocyte-neuron communication in neuronal development and synaptic plasticity has become increasingly clear. Since neuron-astrocyte interactions represent highly dynamic and reciprocal processes, we hypothesized that at least part of the involved astrocyte genes may be regulated as a consequence of their interactions with maturing neurons. In order to identify such neuron-induced astrocyte genes in vitro, we tested the effectiveness of the ‘cold jet’, a new method for separation of neurons from co-cultured astrocytes. The cold jet method is performed under ice-cold conditions and avoids protease-mediated isolation of astrocytes or time-consuming centrifugation, yielding intact astrocyte mRNA with approximately 90% of neuronal RNA removed. Using this method, we executed genome-wide profiling in which RNA derived from astrocyte-only cultures was compared with astrocyte RNA derived from differentiating neuron-astrocyte co-cultures. Data analysis revealed changes in expression of a large number of mRNAs and biological processes, including novel findings. Thus, cold jet is an efficient method to separate astrocytes from neurons in co-culture, and in this study reveals that neurons induce robust gene-expression changes in co-cultured astrocytes.
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:The N-Myc Downstream-Regulated Gene 4 (NDRG4), a prominent biomarker for colorectal cancer (CRC), is specifically expressed by enteric neurons. Considering that nerves are important members of the tumor microenvironment, we here establish different Ndrg4 knockout (Ndrg4-/-) CRC models and an in-direct co-culture of primary enteric nervous system (ENS) cells and intestinal organoids to identify whether the ENS, via NDRG4, affects intestinal tumorigenesis. Linking immunostainings and gastrointestinal motility (GI) assays, we show that absence of Ndrg4 does not trigger any functional or morphological GI-abnormalities. However, combining in vivo, in vitro and quantitative proteomics data, we uncover that Ndrg4 knockdown is associated with enlarged intestinal adenoma development and that organoid growth is boosted by the Ndrg4-/- ENS cell secretome, which is enriched for Nidogen-1 (Nid1) and Fibulin-2 (Fbln2). Moreover, NID1 and FBLN2 are expressed in enteric neurons, enhance tumorigenic capacities of CRC cells and are enriched in human CRC secretomes. Hence, we provide evidence that the ENS, via loss of Ndrg4, is involved in colorectal pathogenesis and that ENS-derived Nidogen-1 and Fibulin-2 enhance colorectal carcinogenesis.
Project description:Here, human pluripotent stem cells (hiPSCs and hESCs) were induced to differentiate to enteric neurons through neural crest specification. We sequenced mRNA samples from enteric neuronal differentiation of human pluripotent stem cells at 4 different stage to generate the gene expression profiles of these cells.
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:Neuronal nitric oxide synthase 1 (NOS1) produces the gaseous signaling molecule nitric oxide (NO), which plays important roles in the development and function of the nervous system. The regulation of Nos1 gene expression is incompletely understood. Here, we analyzed the genome-wide distribution of the histone mark H3K4me3 in FACS-purified nitrergic enteric neurons by chromatin immunoprecipitation-sequencing.