Project description:Neural control of visceral organ function is essential for homeostasis and health. Intestinal peristalsis is critical for digestive physiology and host defence and is often dysregulated in gastrointestinal (GI) disorders. Luminal factors, such as diet and microbiota regulate neurogenic programs of gut motility, but the underlying molecular mechanisms remain unclear. Here we show that the transcription factor Aryl hydrocarbon Receptor (AhR) functions as a biosensor in intestinal neural circuits linking their functional output to the microbial environment of the gut lumen. Using nuclear RNA sequencing of mouse enteric neurons representing distinct intestinal segments and microbiota states, we demonstrate that the intrinsic neural networks of the colon exhibit unique transcriptional profiles controlled by the combined effects of host genetic programmes and microbial colonisation. Microbiota-induced expression of AhR in neurons of the distal gastrointestinal tract enables them to respond to the luminal environment and induce expression of neuron-specific effector mechanisms. Neuron-specific deletion of Ahr or constitutive overexpression of its negative feedback regulator CYP1A1, results in reduced peristaltic activity of the colon, similar to that observed in microbiota-depleted mice. Finally, expression of Ahr in enteric neurons of antibiotic-treated mice partially restores intestinal motility. Taken together, our experiments identify AhR signalling in enteric neurons as a regulatory node that integrates the luminal environment with the physiological output of intestinal neural circuits towards gut homeostasis and health. The enteric nervous system (ENS) encompasses the intrinsic neural networks of the gastrointestinal (GI) tract, which regulate most aspects of intestinal physiology, including peristalsis. In addition to host-specific genetic programmes, microbiota and diet have emerged as critical regulators of gut tissue physiology and changes in the microbial composition of the lumen often accompany GI disorders. We found that gut environmental sensor Aryl hydrocarbon receptor (AhR) is induced in colonic neurons in response to microbiota colonisation and regulates intestinal peristalsis in an AhR ligand-dependent manner. In this experiment, we used RNA sequencing to identify genes regulated in mouse colonic neurons by AhR activation.
Project description:Neural control of visceral organ function is essential for homeostasis and health. Intestinal peristalsis is critical for digestive physiology and host defence and is often dysregulated in gastrointestinal (GI) disorders. Luminal factors, such as diet and microbiota regulate neurogenic programs of gut motility, but the underlying molecular mechanisms remain unclear. Here we show that the transcription factor Aryl hydrocarbon Receptor (AhR) functions as a biosensor in intestinal neural circuits linking their functional output to the microbial environment of the gut lumen. Using nuclear RNA sequencing of mouse enteric neurons representing distinct intestinal segments and microbiota states, we demonstrate that the intrinsic neural networks of the colon exhibit unique transcriptional profiles controlled by the combined effects of host genetic programmes and microbial colonisation. Microbiota-induced expression of AhR in neurons of the distal gastrointestinal tract enables them to respond to the luminal environment and induce expression of neuron-specific effector mechanisms. Neuron-specific deletion of Ahr or constitutive overexpression of its negative feedback regulator CYP1A1, results in reduced peristaltic activity of the colon, similar to that observed in microbiota-depleted mice. Finally, expression of Ahr in enteric neurons of antibiotic-treated mice partially restores intestinal motility. Taken together, our experiments identify AhR signalling in enteric neurons as a regulatory node that integrates the luminal environment with the physiological output of intestinal neural circuits towards gut homeostasis and health. The enteric nervous system (ENS) encompasses the intrinsic neural networks of the gastrointestinal (GI) tract, which regulate most aspects of intestinal physiology, including peristalsis. In addition to host-specific genetic programmes, microbiota and diet have emerged as critical regulators of gut tissue physiology and changes in the microbial composition of the lumen often accompany GI disorders. However the molecular mechanisms by which gut enviromental factors regulate ENS homeostasis remain unknown. In order to address this issue, we used RNA sequencing to identify genes specifically upregulated in mouse colonic neurons in response to microbial colonisation.
Project description:Neural control of visceral organ function is essential for homeostasis and health. Intestinal peristalsis is critical for digestive physiology and host defence and is often dysregulated in gastrointestinal (GI) disorders. Luminal factors, such as diet and microbiota regulate neurogenic programs of gut motility, but the underlying molecular mechanisms remain unclear. Here we show that the transcription factor Aryl hydrocarbon Receptor (AhR) functions as a biosensor in intestinal neural circuits linking their functional output to the microbial environment of the gut lumen. Using nuclear RNA sequencing of mouse enteric neurons representing distinct intestinal segments and microbiota states, we demonstrate that the intrinsic neural networks of the colon exhibit unique transcriptional profiles controlled by the combined effects of host genetic programmes and microbial colonisation. Microbiota-induced expression of AhR in neurons of the distal gastrointestinal tract enables them to respond to the luminal environment and induce expression of neuron-specific effector mechanisms. Neuron-specific deletion of Ahr or constitutive overexpression of its negative feedback regulator CYP1A1, results in reduced peristaltic activity of the colon, similar to that observed in microbiota-depleted mice. Finally, expression of Ahr in enteric neurons of antibiotic-treated mice partially restores intestinal motility. Taken together, our experiments identify AhR signalling in enteric neurons as a regulatory node that integrates the luminal environment with the physiological output of intestinal neural circuits towards gut homeostasis and health. The enteric nervous system (ENS) encompasses the intrinsic neural networks of the gastrointestinal (GI) tract, which regulate most aspects of intestinal physiology, including peristalsis. In addition to host-specific genetic programmes, microbiota and diet have emerged as critical regulators of gut tissue physiology and changes in the microbial composition of the lumen often accompany GI disorders. However the molecular mechanisms by which gut enviromental factors regulate ENS homeostasis remain unknown. In order to address this issue, we used RNA sequencing to identify genes specifically upregulated in mouse colonic neurons in response to microbial colonisation.
Project description:Mucus produced by goblet cells in the gastrointestinal (GI) tract forms a biological barrier that protects the intestine from invasion by commensals and pathogens. However, the host-derived regulatory network that controls mucus secretion and thereby changing gut microbiota has not been well studied. We found Forkhead box protein O1 (Foxo1) regulates mucus secretion by goblet cells and determines intestinal homeostasis. Loss of Foxo1 in intestinal epithelial cells (IECs) results in a defect in goblet cell autophagy and mucus secretion, leading to impaired gut microenvironment and dysbiosis.
Project description:Reconstitution of stem cells and enhancement of the barrier function of the gastrointestinal (GI) tract is critical to the resolution of intestinal acute graft-versus-host disease (aGvHD). Previously, our group has shown in murine models that type II innate lymphoid cells (ILC2) cells generate proteins in the GI tract that enhanced GI tract barrier function and diminished the expansion and function of pro-inflammatory donor cells when given to allogeneic stem cell transplant recipients. Therefore, the infusion of donor ILC2 cells could treat or prevent GI tract acute GvHD, but for this approach to be clinically applicable, robust expansion of a homogenous population of human ILC2 cells is needed. Here, we describe a method for the rapid expansion of a uniform population of human ILC2 cells which decrease GvHD in (NOD scid gamma mouse) NSG mice. The addition of IL-4 to the culture was critical to prevent the expansion of pro-inflammatory ILC1-like cells. Our approach should allow for the evaluation of human ILC2 cells to treat therapy-resistant GI tract acute GvHD.
Project description:Caudal type homeobox 2 (CDX2) is a transcription factor expressed in the gastrointestinal (GI) epithelial (IEC) and stromal cells .CDX2 along with APC can regulate Lgr5 intestinal stem cell (ISC) differentiation to control GI tract development or intestinal neoplasia. CDX2 or APC loss function is associated with colorectal cancer (CRC) advance. However, whether APC directly regulates CRC metastasis is not clear. We aim to determine the role of inactive Apc gene in Cdx2 GI cells on Lgr5 ISC metastasis.
Project description:Gastrointestinal (GI) mucus is continuously secreted and lines the entire length of the GI tract. Essential for health, it keeps the noxious luminal content away from the epithelium and propels forward the digesta. The aim of our study was to characterize the composition and structures of mucus throughout the various GI segments in dog. Mucus from the stomach, small intestine (duodenum, jejunum, ileum), and large intestine (cecum, proximal and distal colon) was collected from 5 dogs. pH and water content of GI mucus and digesta were analyzed. Composition of all GI-tract segments from a domestic and a laboratory dog was determined by label-free global proteomics. A colonic-focussed composition analysis with TMT-labelled proteomics was used on jenunal and proximal and distal colonic mucus samples from 3 laboratory and 1 domestic dog. Finally, the composition of jejunal and colonic mucus samples of 3 laboratory and 1 domestic dog was evaluated with lipidomics and metabolomics. Structural properties were investigated using cryoSEM and rheology. The proteome was similar across the different GI segments. The highest abundant secreted gel-forming mucin in the gastric mucus was mucin 5AC, whether mucin 2 had highest abundance in the intestinal mucus. Lipid and metabolite abundance was generally higher in the jejunal mucus than the colonic mucus. In conclusion, the mucus is a highly viscous and hydrated material. The proteins, lipids and metabolites were similar throughout the GI tract, although abundances depended on location. These data provide an important baseline for future studies on human and canine intestinal diseases and the dog model in drug absorption.
Project description:We profiled transcriptome and accessible chromatin landscapes in intestinal epithelial cells (IECs) from mice reared in the presence or absence of microbiota. We show that regional differences in gene transcription along the intestinal tract were accompanied by major alterations in chromatin organization. Surprisingly, we discovered that microbiota modify host gene transcription in IECs without significantly impacting the accessible chromatin landscape. Instead, microbiota regulation of host gene transcription might be achieved by differential expression of specific TFs and enrichment of their binding sites in nucleosome depleted CRRs near target genes. Our results suggest that the chromatin landscape in IECs is pre-programmed by the host in a region-specific manner to permit responses to microbiota through binding of open CRRs by specific TFs. mRNA and accessible chromatin (DNase-seq) profiles from colonic and ileal IECs were compared between conventionally-raised (CR), germ-free (GF), and conventionalized (CV) C57BL/6 mice.
Project description:Reconstitution of stem cells and enhancement of the barrier function of the gastrointestinal (GI) tract is critical to the resolution of intestinal acute graft-versus-host disease (aGvHD). Previously, our group has shown in murine models that type II innate lymphoid cells (ILC2) cells generate proteins in the GI tract that enhanced GI tract barrier function and diminished the expansion and function of pro-inflammatory donor cells when given to allogeneic stem cell transplant recipients. Therefore, the infusion of donor ILC2 cells could treat or prevent GI tract acute GvHD, but for this approach to be clinically applicable, robust expansion of a homogenous population of human ILC2 cells is needed. Here, we describe a method for the rapid expansion of a uniform population of human ILC2 cells which decrease GvHD in (NOD scid gamma mouse) NSG mice. The addition of IL-4 to the culture was critical to prevent the expansion of pro-inflammatory ILC1-like cells. Our approach should allow for the evaluation of human ILC2 cells to treat therapy-resistant GI tract acute GvHD.