Project description:During the later stages of enteric nervous system (ENS) development, enteric neural crest derived cells (ENCDC) that have colonized the bowel must complete differentiating and mature into neurons and glia. This process is controlled by a complex array of intrinsic and extrinsic factors. We used microarrays to dermine which genes were differntially expressed in ENCDC versus other cells in the developing bowel. We identified many geness enriched in ENCDC with potential roles in the later stages of ENS development
Project description:Epigenetic regulatory mechanisms are underappreciated but critical for enteric nervous system (ENS) development and maintenance. We discovered that fetal loss of the epigenetic regulator Bap1 in the ENS lineage causes severe postnatal bowel dysfunction and early death in Tyrosinase-Cre; Bap1fl/fl mice. Bap1-depleted ENS appears normal in neonates, however, by postnatal day 15 (P15), Bap1-deficient enteric neurons are largely absent from the small and large intestine of Tyrosinase-Cre; Bap1fl/fl mice. Bowel motility becomes markedly abnormal with disproportionate loss of cholinergic neurons. Single-cell RNA sequencing at P5 shows that fetal Bap1 loss inTyrosinase-Cre; Bap1fl/fl mice markedly alters the composition and relative proportions of enteric neuron subtypes. In contrast, postnatal deletion of Bap1 did not cause enteric neuron loss or impaired bowel motility. These findings suggest that BAP1 is critical for postnatal enteric neuron differentiation and for enteric neuron survival.
Project description:The enteric nervous system (ENS) is an essential network of neurons and glia in the bowel wall. Defects in ENS development can result in Hirschsprung disease (HSCR), a life-threatening condition characterized by severe constipation, abdominal distention, bilious vomiting, and failure to thrive. A growing body of literature connects HSCR to alterations in miRNA expression, but there are limited data on the normal miRNA landscape in the developing ENS. We sequenced small RNAs (smRNA-seq) and messenger RNAs (mRNA-seq) in ENS precursors of mid-gestation Ednrb-EGFP mice and compared them to aggregated RNA from all other cells in the developing bowel. Our smRNA-seq results identified 73 miRNAs that were significantly enriched and highly expressed in the developing ENS, with miR-9, miR-27b, miR-124, miR-137, and miR-488 as our top 5 miRNAs that are conserved in humans. However, contrary to prior reports, our follow-up analyses of miR-137 showed that loss of Mir137 in Nestin-cre, Wnt1-cre, Sox10-cre, or Baf53b-cre lineage cells had no effect on mouse survival or ENS development. Our data provide important context for future studies of miRNA in HSCR and other ENS diseases and highlight open questions about facility-specific factors in development.
Project description:The enteric nervous system (ENS) is an essential network of neurons and glia in the bowel wall. Defects in ENS development can result in Hirschsprung disease (HSCR), a life-threatening condition characterized by severe constipation, abdominal distention, bilious vomiting, and failure to thrive. A growing body of literature connects HSCR to alterations in miRNA expression, but there are limited data on the normal miRNA landscape in the developing ENS. We sequenced small RNAs (smRNA-seq) and messenger RNAs (mRNA-seq) in ENS precursors of mid-gestation Ednrb-EGFP mice and compared them to aggregated RNA from all other cells in the developing bowel. Our smRNA-seq results identified 73 miRNAs that were significantly enriched and highly expressed in the developing ENS, with miR-9, miR-27b, miR-124, miR-137, and miR-488 as our top 5 miRNAs that are conserved in humans. However, contrary to prior reports, our follow-up analyses of miR-137 showed that loss of Mir137 in Nestin-cre, Wnt1-cre, Sox10-cre, or Baf53b-cre lineage cells had no effect on mouse survival or ENS development. Our data provide important context for future studies of miRNA in HSCR and other ENS diseases and highlight open questions about facility-specific factors in development.
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:The enteric nervous system (ENS) is contained within two layers of the gut wall and is made up of neurons, immune cells, and enteric glia cells (EGCs) that regulate gastrointestinal (GI) function. EGCs in both inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS) change in response to inflammation, referred to as reactive gliosis. Whether EGCs restricted to a specific layer or region within the GI tract alone can influence intestinal immune response is unknown. Using bulk RNA-sequencing and in situ hybridization, we identify G-protein coupled receptor, Gpr37, as a gene expressed only in EGCs of the myenteric plexus, one of the two layers of the ENS. We show that Gpr37 contributes to key components of LPS-induced reactive gliosis including activation of NF-kB and IFN-y signaling and response genes, lymphocyte recruitment, and inflammation-induced GI dysmotility. Targeting Gpr37 in EGCs presents a potential avenue for modifying inflammatory processes in the ENS.
Project description:The enteric nervous system (ENS) can control most essential gut functions owing to its organization into complete neural circuits consisting of a multitude of different neuronal subtypes. We used microarrays to identify transcription factor networks and signaling pathways involved in diversification and differentiation of enteric neurons during development of the enteric nervous system.
Project description:Besides symptoms caused by central nervous system (CNS) lesions, the majority of patients with multiple sclerosis (MS) also exhibit gastrointestinal dysfunction that has frequently been noted, but was not directly linked to the autoimmune etiology of the disease.We studied the enteric nervous system (ENS) in a murine model of MS by histology and electron microscopy. Serum IgG against enteric neurons and enteroglia was measured by ELISA and binding to the ENS was confirmed by immunohistochemistry. Target antigens were identified by mass spectrometry. Gastrointestinal dysfunction was determined by measuring dye transit time. RNA expression profiling was conducted with small intestines of MP4-immunized and control-immunized mice. Data from the mouse model were confirmed in MS patients by immunohistochemistry of the ENS in bowel resectates. In addition, ELISA was performed on plasma samples to detect antibodies against four specific target antigens as identified in the mouse model. ENS degeneration was evident already before the onset of clinical disease in the mouse model. Pathology was predominantly antibody-mediated and caused a significant decrease in gastrointestinal transit, which was associated with severe gliosis of the ENS. Unlike the dense infiltrates that developed in the perivascular compartments of the CNS of MP4-immunized mice, the infiltrates in the ENS consisted of single cells scattered throughout the tissue. RNA expression profiling could support these results, as the expression of inflammatory markers in the small intestine was similar between MP4-immunized and HEL-immunized mice. We identified four specific target antigens derived from enteric neurons and/or enteroglia. Antibodies against all four target antigens were present in MS patients. MS patients also showed gliosis and signs of ENS degeneration in the small intestine. For the first time, this study establishes a pathomechanistic link between the well-established autoimmune attack on the CNS and the ENS in MS. The presence of ENS pathology prior to CNS degeneration introduces entirely novel ways to explain MS etiology and immunopathogenesis.
Project description:The enteric nervous system (ENS) encompasses the intrinsic neuroglia networks of the gastrointestinal (GI) tract that are essential for digestive function and gut homeostasis. To investigate the ENS of zebrafish, we carried out bulk RNA sequencing on nuclei purified by FACS (fluorescent-activated cell sorting) representing both the Cherry+ (ENS) and Cherry- (non-ENS) muscularis externa cell populations of Tg(sox10:Cre;Cherry) zebrafish gut.