Key Points: Neurogenic gut movements start after longitudinal smooth muscle differentiation in three species (mouse, zebrafish, chicken), and at E16 in the chicken embryo. The first activity of the chicken enteric nervous system is dominated by inhibitory neurons. The embryonic enteric nervous system electromechanically couples circular and longitudinal spontaneous myogenic contractions, thereby producing a new, rostro-caudally directed bolus transport pattern: the migrating motor complex. The response of the embryonic gut to mechanical stimulation evolves from a symmetric, myogenic response at E12, to a neurally mediated, polarized, descending inhibitory, 'law of the intestine'-like response at E16. High resolution, whole-mount 3D reconstructions are presented of the enteric nervous system of the chicken embryo at the neural-control stage E16 with the iDISCO+ tissue clarification technique.
Abstract: Gut motility is a complex transport phenomenon involving smooth muscle, enteric neurons, glia and interstitial cells of Cajal. Because these different cells differentiate and become active at different times during embryo development, studying the ontogenesis of motility offers a unique opportunity to 'time-reverse-engineer' the peristaltic reflex. Working on chicken embryo intestinal explants in vitro, we found by spatio-temporal mapping and signal processing of diameter and position changes that motility follows a characteristic sequence of increasing complexity: (1) myogenic circular smooth muscle contractions from E6 to E12 that propagate as waves along the intestine, (2) overlapping and independent, myogenic, low-frequency, bulk longitudinal smooth muscle contractions around E14, and (3) tetrodotoxin-sensitive coupling of longitudinal and circular contractions by the enteric nervous system as from E16. Inhibition of nitric oxide synthase neurons shows that the coupling consists in nitric oxide-mediated relaxation of circular smooth muscle when the longitudinal muscle layer is contracted. This mechanosensitive coupling gives rise to a directional, cyclical, propagating bolus transport pattern: the migrating motor complex. We further reveal a transition to a polarized, descending, inhibitory reflex response to mechanical stimulation after neuronal activity sets in at E16. This asymmetric response is the elementary mechanism responsible for peristaltic transport. We finally present unique high-resolution 3D reconstructions of the chicken enteric nervous system at the neural-control stage based on confocal imaging of iDISCO+ clarified tissues. Our study shows that the enteric nervous system gives rise to new peristaltic transport patterns during development by coupling spontaneous circular and longitudinal smooth muscle contraction waves.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6826228 | PMC |
http://dx.doi.org/10.1113/JP277746 | DOI Listing |
Cardiol Rev
January 2025
Department of Internal Medicine, Milton S Hershey Medical Center, Hershey, PA.
Moyamoya disease (MMD) is a vascular disorder characterized by steno-occlusive alterations in cerebral arteries, often resulting in ischemic or hemorrhagic events predominantly affecting the female population and more common in Asian populations. Despite its predominantly neurological manifestations, recent research suggests a potential association between MMD and cardiovascular diseases (CVDs). MMD involves various genetic and environmental factors, with mutations in the RNF213 gene being strongly implicated in disease susceptibility, with histopathological findings revealing intimal lesions and smooth muscle proliferation, contributing to vascular occlusion as well as dysregulation of circulating endothelial and smooth muscle progenitor cells further complicating MMD's pathogenesis.
View Article and Find Full Text PDFRegen Ther
March 2025
Pediatric Urology and Regenerative Medicine Research Center, Gene Cell and Tissue Research Institute Children Medical Center, Tehran University of Medical Sciences, Tehran, Iran.
Tissue engineering has been considered a potential choice for urinary system reconstruction. Here, we aim to a broad spectrum of employed stem cells in bladder regeneration by performing a comprehensive systematic review. In January 2024, we searched Scopus, PubMed, and Embase databases for studies that tried bladder regeneration by tissue engineering using stem cells.
View Article and Find Full Text PDFJVS Vasc Sci
December 2024
Department of Cardiovascular Science, Lewis Katz School of Medicine at Temple University, Philadelphia, PA.
Treatment with an inhibitor of glucose use via glucose transporters (GLUT) has been shown to attenuate experimental abdominal aortic aneurysm (AAA) development in mice. Vascular smooth muscle cell (VSMC) signaling seems to be essential for angiotensin II (Ang II)-induced AAA in mice. Accordingly, we have tested a hypothesis that VSMC silencing of the major GLUT, GLUT1, prevents AAA development and rupture in mice treated with Ang II plus β-aminopropionitrile.
View Article and Find Full Text PDFEClinicalMedicine
January 2025
Department of Mathematics, University of Auckland, Auckland, New Zealand.
With the impending 'retirement' of bronchial thermoplasty (BT) for the treatment of patients with asthma, there is much to learn from this real-world experiment that will help us develop more effective future therapies with the same primary target i.e., airway smooth muscle (ASM) remodelling.
View Article and Find Full Text PDFNat Cardiovasc Res
January 2025
Shanghai Fifth People's Hospital and Institutes of Biomedical Sciences Zhongshan Hospital, Shanghai Medical College, Fudan University, Shanghai, China.
Loss-of-function mutations in NOTCH1 were previously linked to thoracic aortopathy, a condition for which non-surgical treatment options are limited. Based on clinical proteome analysis, we hypothesized that mitochondrial fusion and biogenesis in aortic smooth muscle cells (SMCs) are crucial for regulating the progression of NOTCH1-related aortopathy. Here we demonstrate that SMC-specific Notch1 knockout mice develop aortic pathology, including stiffening, dilation and focal dissection.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!