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:The Aryl Hydrocarbon Receptor (AHR) regulates the expression of numerous genes in response to activation by agonists including xenobiotics. Although it is well appreciated that environmental signals and cell intrinsic features may modulate this transcriptional response, how it is mechanistically achieved remains poorly understood. We show that Hexokinase 2 (HK2) a metabolic enzyme fuelling cancer cell growth, is a transcriptional target of AHR as well as a modulator of its activity. Expression of HK2 is positively regulated by AHR upon exposure to agonists both in human cells and in mice lung tissues. Conversely, over-expression of HK2 regulates the abundance of many proteins involved in the regulation of AHR signalling and these changes are linked with altered AHR expression levels and transcriptional activity. HK2 expression also shows a negative correlation with AHR promoter methylation in tumours, and these tumours with high HK2 expression and low AHR methylation are associated with a worse overall survival in patients. In sum, our study provides novel insights into how AHR signalling is regulated which may help our understanding of the context-specific effects of this pathway and may have implications in cancer.
Project description:This study investigates the phenomenon of postnatal plasticity within the enteric nervous system (ENS), specifically investigating the reinnervation potential of post-mitotic enteric neurons. Employing BAF53b-Cre for selective tracing, the reinnervation capabilities of postnatal enteric neurons in multiple model systems are shown. Denervated enteric neurons exhibit the ability to regenerate neurites in vitro, with neurite complexity and direction notably influenced by contact with enteric glial cells (EGCs). In vivo nerve fibers from transplanted enteric neurons exclusively interface with EGCs. Resident EGCs are sustained after Cre dependent ablation of enteric neurons and govern the architecture of the ENS by reinnervating enteric neurons. Transplantation experiments underscore the swift reintegration and reinnervation potential of post-mitotic neurons, leading to restored muscle function within two weeks. Optogenetic investigations further delineate time-dependent functional recovery via transplantation of isolated enteric ganglia. These revelations demonstrate the structural and functional reinnervation capacity of post-mitotic enteric neurons, underscored by EGC guidance.
Project description:The blood and lymphatic vasculature is lined by functionally specialised endothelial cells (ECs). In the intestine, ECs act as an essential physical barrier, controlling nutrient transport, facilitating tissue immunosurveillance, and coordinating angiogenesis and lymphangiogenesis to ensure appropriate tissue perfusion and drainage. Conversely, endothelial maladaptation can lead to pathological angiogenesis and the perpetuation of inflammation in chronic inflammatory diseases. However, whether enteric ECs actively engage in the regulation of intestinal homeostasis and pathology through integration of environmental cues is currently unknown. Here, we show that the aryl hydrocarbon receptor (AHR), a ligand-activated transcription factor, acts as critical node for EC-sensing of dietary and microbial metabolites. We first established a comprehensive single-cell endothelial atlas of the mouse small intestine uncovering the cellular complexity and functional heterogeneity of blood and lymphatic ECs, identifying transcriptional networks and putative biological roles across endothelial subtypes. Analyses of AHR mediated responses at single-cell resolution identified tissue-protective transcriptional signatures and regulatory networks promoting quiescence and vasculoprotection. Endothelial AHR-deficiency in mice resulted in cellular activation, proliferation, and initiation of angiogenic pathways disrupting tissue homeostasis. In human ECs, AHR signalling promoted quiescence through cell cycle arrest and tempered endothelial inflammatory responses. Together, our data provide a comprehensive dissection of the impact of environmental sensing across the spectrum of enteric endothelia, demonstrating that endothelial AHR signalling serves to promote homeostasis and prevent aberrant inflammatory responses at the intestinal barrier.
Project description:This study was undertaken to define the molecular subtypes of cells within enteric neurospheres. Methods: We performed single-cell RNA sequencing on 3-dimensional neurosphere cultures derived from the small intestines of Plp1::GFP mice. These data show profiling results from the PLP1::GFP negative cell fraction ancillary to the positive fraction in series GSE184981. Results: We identify populations of enteric neurons and fibroblasts in the PLP1::GFP negative cell fraction of enteric neurospheres.
Project description:The blood and lymphatic vasculature is lined by functionally specialised endothelial cells (ECs). In the intestine, ECs act as an essential physical barrier, controlling nutrient transport, facilitating tissue immunosurveillance, and coordinating angiogenesis and lymphangiogenesis to ensure appropriate tissue perfusion and drainage. Conversely, endothelial maladaptation can lead to pathological angiogenesis and the perpetuation of inflammation in chronic inflammatory diseases. However, whether enteric ECs actively engage in the regulation of intestinal homeostasis and pathology through integration of environmental cues is currently unknown. Here, we show that the aryl hydrocarbon receptor (AHR), a ligand-activated transcription factor, acts as critical node for EC-sensing of dietary and microbial metabolites. We first established a comprehensive single-cell endothelial atlas of the mouse small intestine uncovering the cellular complexity and functional heterogeneity of blood and lymphatic ECs, identifying transcriptional networks and putative biological roles across endothelial subtypes. Analyses of AHR mediated responses at single-cell resolution identified tissue-protective transcriptional signatures and regulatory networks promoting quiescence and vasculoprotection. Endothelial AHR-deficiency in mice resulted in cellular activation, proliferation, and initiation of angiogenic pathways disrupting tissue homeostasis. In human ECs, AHR signalling promoted quiescence through cell cycle arrest and tempered endothelial inflammatory responses. Together, our data provide a comprehensive dissection of the impact of environmental sensing across the spectrum of enteric endothelia, demonstrating that endothelial AHR signalling serves to promote homeostasis and prevent aberrant inflammatory responses at the intestinal barrier.