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:Glial cells of the enteric nervous system (ENS) interact closely with the intestinal epithelium and secrete signals that influence epithelial cell proliferation and barrier formation in vitro. Whether these interactions are important in vivo, however, is unclear because previous studies reached conflicting conclusions. To better define the roles of enteric glia in steady state regulation of the intestinal epithelium, we characterized the glia in closest proximity to epithelial cells and found that the majority express PLP1 in both mice and humans. To test their functions using an unbiased approach, we genetically depleted PLP1+ cells in mice and transcriptionally profiled the small and large intestines. Surprisingly, glial loss had minimal effects on transcriptional programs and the few identified changes varied along the gastrointestinal tract. In the ileum, where enteric glia had been considered most essential for epithelial integrity, glial depletion did not drastically alter epithelial gene expression but caused a modest enrichment in signatures of Paneth cells, a secretory cell type important for innate immunity. In the absence of PLP1+ glia, Paneth cell number was intact, but a subset appeared abnormal with irregular and heterogenous cytoplasmic granules, suggesting a secretory deficit. Consistent with this possibility, ileal explants from glial-depleted mice secreted less functional lysozyme than controls with corresponding effects on fecal microbial composition. Collectively, these data suggest that enteric glia do not exert broad effects on the intestinal epithelium but have an essential role in regulating Paneth cell function and gut microbial ecology.
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:Enteric glial cells are important players in the control of motility, intestinal barrier integrity and inflammation. During inflammation, they switch into a reactive phenotype enabling them to release inflammatory mediators, thereby shaping the inflammatory environment. While a plethora of well-established in vivo models exist, cell culture models necessary to decipher the mechanistic pathways of enteric glial reactivity are less well standardized. In particular, the composition of extracellular matrices (ECM) can massively affect the experimental outcome. Considering the growing number of studies involving primary enteric glial cells, a better understanding of their homeostatic and inflammatory in vitro culture conditions is needed. We examined the impact of different ECMs on enteric glial culture homeostasis and immune responsiveness. We used 3’ bulk mRNA sequencing to compare cultured cells with in vivo enteric glial transcriptomes isolated from Sox10iCreERT2Rpl22HA/+ mice. Transcriptional analysis revealed strong similarities between enteric glia on Matrigel and laminin with enrichment of gene sets supporting neuronal differentiation, while cells on poly-L-ornithine showed enrichment related to cell proliferation. Comparing cultured and in vivo enteric glial transcriptomes revealed a 50% overlap. IL-1β treatment showed distinct coating-dependent gene expression signatures, with an enrichment of genes related to myeloid and epithelial cell differentiation on Matrigel and laminin coatings, while poly-L-ornithine induced more gene sets related to lymphocyte differentiation. Together, changes in differentiation and immune activation of primary enteric glial cells proved a strong effect of the ECM. We identified Matrigel and laminin as pre-eminent substrates for murine enteric glial cultures. These new insights will help to standardize and improve enteric glial culture quality and reproducibility between studies in the future, allowing a better comparison of their functional role in enteric neuroinflammation.
Project description:Glial cells have been proposed as an endogenous source of progenitors for the treatment of neural deficits. However, the cellular and molecular mechanisms underpinning the neurogenic potential of certain populations of adult glial cells, are not known. Using single cell transcriptomic profiling, we show here that enteric glial cells represent a cell state attained by autonomic neural crest cells as they transition during development along a linear default differentiation trajectory that allows them to retain neurogenic potential while acquiring a gene expression profile associated with their role in neuronal support and immunomodulation. Key neurogenic loci in early enteric nervous system progenitors remain in open chromatin configuration in mature enteric glia, thus facilitating neuronal differentiation under appropriate conditions. Molecular profiling and gene targeting of enteric glial cells in a novel cell culture system of enteric neurogenesis and a gut injury model, demonstrated that neuronal differentiation of glia is driven by transcriptional programs employed in vivo by early progenitors. Our work provides mechanistic insight into the dynamic regulatory landscape underpinning the development of intestinal neural circuits and generates a platform for advancing glial cells as therapeutic agents for the treatment of neural deficits.
Project description:Glial cells have been proposed as an endogenous source of progenitors for the treatment of neural deficits. However, the cellular and molecular mechanisms underpinning the neurogenic potential of certain populations of adult glial cells, are not known. Using single cell transcriptomic profiling, we show here that enteric glial cells represent a cell state attained by autonomic neural crest cells as they transition during development along a linear default differentiation trajectory that allows them to retain neurogenic potential while acquiring a gene expression profile associated with their role in neuronal support and immunomodulation. Key neurogenic loci in early enteric nervous system progenitors remain in open chromatin configuration in mature enteric glia, thus facilitating neuronal differentiation under appropriate conditions. Molecular profiling and gene targeting of enteric glial cells in a novel cell culture system of enteric neurogenesis and a gut injury model, demonstrated that neuronal differentiation of glia is driven by transcriptional programs employed in vivo by early progenitors. Our work provides mechanistic insight into the dynamic regulatory landscape underpinning the development of intestinal neural circuits and generates a platform for advancing glial cells as therapeutic agents for the treatment of neural deficits.
Project description:Enteric glia are the predominant cell type in the enteric nervous system yet their identities and roles in gastrointestinal function are not well classified. Using our optimized single nucleus RNA-sequencing method, we identified distinct molecular classes of enteric glia and defined their morphological and spatial diversity. Our findings revealed a functionally specialized biosensor subtype of enteric glia that we call “hub cells.” Deletion of the mechanosensory ion channel PIEZO2 from adult enteric glial hub cells, but not other subtypes of enteric glia, led to defects in intestinal motility and gastric emptying in mice. These results provide insight into the multifaceted functions of different enteric glial cell subtypes in gut health and emphasize that therapies targeting enteric glia could advance the treatment of gastrointestinal diseases.
Project description:Enteric nervous system (ENS) development relies on intestinal colonization by enteric neural crest-derived cells (ENCDCs). This is driven by a population of highly migratory and proliferative cells at the wavefront, but the unique molecular characteristics of the wavefront are unknown. ENCDCs from the wavefront and the trailing region proximal were isolated from 11.5 days post coitum (dpc) Wnt1-tdT mouse intestine and subjected to RNA-seq. Wavefront ENCDCs were transcriptionally distinct from trailing ENCDCs, and temporal modelling confirmed their relative immaturity. Wavefront ENCDCs exhibited altered expression of ECM and cytoskeletal genes, consistent with a migratory phenotype. Unlike postnatal enteric neural stem cells, wavefront ENCDCs possessed characteristics of cells undergoing epithelial-mesenchymal transition and lacked neuronal or glial commitment.