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Abstract The enteric nervous system (ENS) is the intrinsic nervous system of the gut and controls essential functions, such as gut motility, intestinal barrier function, and water balance. The ENS displays a complex 3D architecture within the context of the gut and specific transcriptional states needed to control gut homeostasis. During development, the ENS develops from enteric neural progenitor cells (ENPs) that migrate into the gut and differentiate into functionally diverse neuron types. Incorrect ENS development can disrupt ENS function and induce various gut disorders, including the congenital disease Hirschsprung disease, or various other functional gut neurological disorders, such as esophageal achalasia. In this study, we used the zebrafish larval model and performed whole gut spatial genomic analysis (SGA) of the differentiating ENS at cellular resolution. To that end, a pipeline was developed that integrated early and late developmental ENS stages by linking various spatial and transcriptional dimensions to discover regionalized cellular groups and their co-expression similarity. We identified 3D networks of intact ENS surrounding the gut and predicted cellular connectivity properties based on the stage. Spatial variable genes, such ashoxb5b,hoxa4a,etv1, andret, were regionalized along gut axes, suggesting they may have a precise spatiotemporal control of ENS development. The application of SGA to ENS development provides new insights into its cellular transcriptional networks and interactions, and provides a baseline data set to further advance our understanding of gut neurodevelopmental disorders such as Hirschsprung disease and congenital enteric neuropathies.
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The Vibrio type VI secretion system induces intestinal macrophage redistribution and enhanced intestinal motility
Intestinal microbes, whether resident or transient, influence the physiology of their hosts, altering both the chemical and the physical characteristics of the gut. An example of the latter is the human pathogenVibrio cholerae’sability to induce strong mechanical contractions, discovered in zebrafish. The underlying mechanism has remained unknown, but the phenomenon requires the actin crosslinking domain (ACD) ofVibrio’s type VI secretion system (T6SS), a multicomponent protein syringe that pierces adjacent cells and delivers toxins. By using a zebrafish-nativeVibrioand imaging-based assays of host intestinal mechanics and immune responses, we find evidence that macrophages mediate the connection between the T6SS ACD and intestinal activity. Inoculation withVibriogives rise to strong, ACD-dependent, gut contractions whose magnitude resembles those resulting from genetic depletion of macrophages.Vibrioalso induces tissue damage and macrophage activation, both ACD-dependent, recruiting macrophages to the site of tissue damage and away from their unperturbed positions near enteric neurons that line the midgut and regulate intestinal motility. Given known crosstalk between macrophages and enteric neurons, our observations suggest that macrophage redistribution forms a key link betweenVibrioactivity and intestinal motility. In addition to illuminating host-directed actions of the widespread T6SS protein apparatus, our findings highlight how localized bacteria-induced injury can reshape neuro-immune cellular dynamics to impact whole-organ physiology. IMPORTANCEGut microbes, whether beneficial, harmful, or neutral, can have dramatic effects on host activities. The human pathogenVibrio choleraecan induce strong intestinal contractions, though how this is achieved has remained a mystery. Using a zebrafish-nativeVibrioand live imaging of larval fish, we find evidence that immune cells mediate the connection between bacteria and host mechanics. A piece ofVibrio’s type VI secretion system, a syringe-like apparatus that stabs cellular targets, induces localized tissue damage, activating macrophages and drawing them from their normal residence near neurons, whose stimulation of gut contractions they dampen, to the damage site. Our observations reveal a mechanism in which cellular rearrangements, rather than bespoke biochemical signaling, drives a dynamic neuro-immune response to bacterial activity.
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- Award ID(s):
- 2310570
- PAR ID:
- 10589485
- Editor(s):
- Graf, Joerg
- Publisher / Repository:
- mBIO / American Society for Microbiology
- Date Published:
- Journal Name:
- mBio
- Volume:
- 16
- Issue:
- 1
- ISSN:
- 2150-7511
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1128/mbio.02419-24
