scholarly journals Adult enteric nervous system in health is maintained by a dynamic balance between neuronal apoptosis and neurogenesis

2017 ◽  
Vol 114 (18) ◽  
pp. E3709-E3718 ◽  
Author(s):  
Subhash Kulkarni ◽  
Maria-Adelaide Micci ◽  
Jenna Leser ◽  
Changsik Shin ◽  
Shiue-Cheng Tang ◽  
...  

According to current dogma, there is little or no ongoing neurogenesis in the fully developed adult enteric nervous system. This lack of neurogenesis leaves unanswered the question of how enteric neuronal populations are maintained in adult guts, given previous reports of ongoing neuronal death. Here, we confirm that despite ongoing neuronal cell loss because of apoptosis in the myenteric ganglia of the adult small intestine, total myenteric neuronal numbers remain constant. This observed neuronal homeostasis is maintained by new neurons formed in vivo from dividing precursor cells that are located within myenteric ganglia and express both Nestin and p75NTR, but not the pan-glial marker Sox10. Mutation of the phosphatase and tensin homolog gene in this pool of adult precursors leads to an increase in enteric neuronal number, resulting in ganglioneuromatosis, modeling the corresponding disorder in humans. Taken together, our results show significant turnover and neurogenesis of adult enteric neurons and provide a paradigm for understanding the enteric nervous system in health and disease.

Development ◽  
1999 ◽  
Vol 126 (12) ◽  
pp. 2785-2797 ◽  
Author(s):  
S. Taraviras ◽  
C.V. Marcos-Gutierrez ◽  
P. Durbec ◽  
H. Jani ◽  
M. Grigoriou ◽  
...  

RET is a member of the receptor tyrosine kinase (RTK) superfamily, which can transduce signalling by glial cell line-derived neurotrophic factor (GDNF) and neurturin (NTN) in cultured cells. In order to determine whether in addition to being sufficient, RET is also necessary for signalling by these growth factors, we studied the response to GDNF and NTN of primary neuronal cultures (peripheral sensory and central dopaminergic neurons) derived from wild-type and RET-deficient mice. Our experiments show that absence of a functional RET receptor abrogates the biological responses of neuronal cells to both GDNF and NTN. Despite the established role of the RET signal transduction pathway in the development of the mammalian enteric nervous system (ENS), very little is known regarding its cellular mechanism(s) of action. Here, we have studied the effects of GDNF and NTN on cultures of neural crest (NC)-derived cells isolated from the gut of rat embryos. Our findings suggest that GDNF and NTN promote the survival of enteric neurons as well as the survival, proliferation and differentiation of multipotential ENS progenitors present in the gut of E12.5-13.5 rat embryos. However, the effects of these growth factors are stage-specific, since similar ENS cultures established from later stage embryos (E14. 5–15.5), show markedly diminished response to GDNF and NTN. To examine whether the in vitro effects of RET activation reflect the in vivo function(s) of this receptor, the extent of programmed cell death was examined in the gut of wild-type and RET-deficient mouse embryos by TUNEL histochemistry. Our experiments show that a subpopulation of enteric NC undergoes apoptotic cell death specifically in the foregut of embryos lacking the RET receptor. We suggest that normal function of the RET RTK is required in vivo during early stages of ENS histogenesis for the survival of undifferentiated enteric NC and their derivatives.


2004 ◽  
Vol 24 (18) ◽  
pp. 8026-8036 ◽  
Author(s):  
Mayumi Jijiwa ◽  
Toshifumi Fukuda ◽  
Kumi Kawai ◽  
Akari Nakamura ◽  
Kei Kurokawa ◽  
...  

ABSTRACT The Ret receptor tyrosine kinase plays a crucial role in the development of the enteric nervous system and the kidney. Tyrosine 1062 in Ret represents a binding site for the phosphotyrosine-binding domains of several adaptor and effector proteins that are important for the activation of intracellular signaling pathways, such as the RAS/ERK, phosphatidylinositol 3-kinase/AKT, and Jun-associated N-terminal kinase pathways. To investigate the importance of tyrosine 1062 for organogenesis in vivo, knock-in mice in which tyrosine 1062 in Ret was replaced with phenylalanine were generated. Although homozygous knock-in mice were born normally, they died by day 27 after birth and showed growth retardation. The development of the enteric nervous system was severely impaired in homozygous mutant mice, about 40% of which lacked enteric neurons in the whole intestinal tract, as observed in Ret-deficient mice. The rest of the mutant mice developed enteric neurons in the intestine to various extents, although the size and number of ganglion cells were significantly reduced. Unlike Ret-deficient mice, a small kidney developed in all knock-in mice, accompanying a slight histological change. The reduction of kidney size was due to a decrease of ureteric bud branching during embryogenesis. Thus, these findings demonstrated that the signal via tyrosine 1062 plays an important role in histogenesis of the enteric nervous system and nephrogenesis.


Development ◽  
2020 ◽  
pp. dev.195339
Author(s):  
Maria Ohno ◽  
Masataka Nikaido ◽  
Natsumi Horiuchi ◽  
Koichi Kawakami ◽  
Kohei Hatta

Enteric nervous system (ENS) which is derived from neural crest is essential for gut function and its deficiency causes severe congenital diseases. Since capacity of ENS regeneration in mammals is limited, additional complimentary models would be useful. Here, we show that the ENS in zebrafish larva at 10-15 days post-fertilization is highly regenerative. The number of enteric neurons (ENs) recovered to ∼50% of the control by 10 days post-ablation (dpa) after their laser ablation. Using transgenic lines in which enteric neural crest-derived cells (ENCDCs) and ENs are labeled with fluorescent proteins, we live-imaged the regeneration process, and found covering by neurites extended from the unablated area and entry of ENCDCs in the ablated areas by 1-3 dpa. BrdU assay suggested that ∼80% of the ENs and ∼90% of the Sox10-positive ENCDCs therein at 7dpa are generated through proliferation. Thus the ENS regeneration involves proliferation, entrance and neurogenesis of ENCDCs. This is the first report regarding the regeneration process of the zebrafish ENS; our findings provide a basis for further in vivo research at single-cell resolution in the vertebrate.


2012 ◽  
Vol 139 (1) ◽  
pp. 47-57 ◽  
Author(s):  
Cornelia Irene Hagl ◽  
Elvira Wink ◽  
Sabrina Scherf ◽  
Sabine Heumüller-Klug ◽  
Barbara Hausott ◽  
...  

Author(s):  
Laura E. Kuil ◽  
Rajendra K. Chauhan ◽  
William W. Cheng ◽  
Robert M. W. Hofstra ◽  
Maria M. Alves

The Enteric Nervous System (ENS) is a large network of enteric neurons and glia that regulates various processes in the gastrointestinal tract including motility, local blood flow, mucosal transport and secretion. The ENS is derived from stem cells coming from the neural crest that migrate into and along the primitive gut. Defects in ENS establishment cause enteric neuropathies, including Hirschsprung disease (HSCR), which is characterized by an absence of enteric neural crest cells in the distal part of the colon. In this review, we discuss the use of zebrafish as a model organism to study the development of the ENS. The accessibility of the rapidly developing gut in zebrafish embryos and larvae, enables in vivo visualization of ENS development, peristalsis and gut transit. These properties make the zebrafish a highly suitable model to bring new insights into ENS development, as well as in HSCR pathogenesis. Zebrafish have already proven fruitful in studying ENS functionality and in the validation of novel HSCR risk genes. With the rapid advancements in gene editing techniques and their unique properties, research using zebrafish as a disease model, will further increase our understanding on the genetics underlying HSCR, as well as possible treatment options for this disease.


2020 ◽  
Author(s):  
Yuta Kobayashi ◽  
Alicia Bukowski ◽  
Subhamoy Das ◽  
Cedric Espenel ◽  
Julieta Gomez-Frittelli ◽  
...  

AbstractHealthy gastrointestinal functions require a healthy Enteric Nervous System (ENS). ENS health is often defined by the presence of normal ENS structure. However, we currently lack a comprehensive understanding of normal ENS structure as current methodologies of manual enumeration of neurons within tissue and ganglia can only parse limited tissue regions; and are prone to error, subjective bias, and peer-to-peer discordance. Thus, there is a need to craft objective methods and robust tools to capture and quantify enteric neurons over a large area of tissue and within multiple ganglia. Here, we report on the development of an AI-driven tool COUNTEN which parses HuC/D-immunolabeled adult murine myenteric ileal plexus tissues to enumerate and classify enteric neurons into ganglia in a rapid, robust, and objective manner. COUNTEN matches trained humans in identifying, enumerating and clustering myenteric neurons into ganglia but takes a fraction of the time, thus allowing for accurate and rapid analyses of a large tissue region. Using COUNTEN, we parsed thousands of myenteric neurons and clustered them in hundreds of myenteric ganglia to compute metrics that help define the normal structure of the adult murine ileal myenteric plexus. We have made COUNTEN freely and openly available to all researchers, to facilitate reproducible, robust, and objective measures of ENS structure across mouse models, experiments, and institutions.


1993 ◽  
Vol 265 (5) ◽  
pp. G1005-G1009 ◽  
Author(s):  
M. Schemann ◽  
H. Sann ◽  
C. Schaaf ◽  
M. Mader

Several different monoclonal and polyclonal antibodies to choline acetyltransferase (ChAT) were screened to identify effective antibodies for immunocytochemical marking of cholinergic neurons in the enteric nervous system. Excellent immunohistochemical results were obtained with two of the antibodies in the myenteric plexus of the guinea pig stomach and small intestine. One was a mouse monoclonal antibody designated B3.9B3, and the second was a rabbit polyclonal antibody referred to as Peptide 3. Both antibodies clearly stained neuronal cell bodies as well as nerve fibers to the muscle layers and fibers encircling stained and unstained cell bodies. Cell counts indicated that approximately 64% (21.0 +/- 8.6 cells/ganglion) of gastric myenteric neurons are ChAT positive. Pelvic ganglia and the inferior mesenteric ganglia were examined as controls. Strong labeling of the majority of neurons was found in the pelvic ganglia, whereas few immunoreactive cells were apparent in the predominantly noradrenergic inferior mesenteric ganglion. Lack of effective antibodies to enteric neuronal ChAT has hampered progress in the study of the neurophysiology of cholinergic neurons in the digestive tract. Application of the B3.9B3 and Peptide 3 antibodies now promises to facilitate investigation of this important subset of enteric neurons.


2021 ◽  
Vol 12 (3) ◽  
Author(s):  
Mi Tian ◽  
Jingjing Wang ◽  
Shangming Liu ◽  
Xinyun Li ◽  
Jingyuan Li ◽  
...  

AbstractThe liver plays an important role in lipid and glucose metabolism. Here, we show the role of human antigen R (HuR), an RNA regulator protein, in hepatocyte steatosis and glucose metabolism. We investigated the level of HuR in the liver of mice fed a normal chow diet (NCD) and a high-fat diet (HFD). HuR was downregulated in the livers of HFD-fed mice. Liver-specific HuR knockout (HuRLKO) mice showed exacerbated HFD-induced hepatic steatosis along with enhanced glucose tolerance as compared with control mice. Mechanistically, HuR could bind to the adenylate uridylate-rich elements of phosphatase and tensin homolog deleted on the chromosome 10 (PTEN) mRNA 3′ untranslated region, resulting in the increased stability of Pten mRNA; genetic knockdown of HuR decreased the expression of PTEN. Finally, lentiviral overexpression of PTEN alleviated the development of hepatic steatosis in HuRLKO mice in vivo. Overall, HuR regulates lipid and glucose metabolism by targeting PTEN.


1996 ◽  
Vol 109 (7) ◽  
pp. 1749-1757 ◽  
Author(s):  
N. Soussi-Yanicostas ◽  
J.P. Hardelin ◽  
M.M. Arroyo-Jimenez ◽  
O. Ardouin ◽  
R. Legouis ◽  
...  

The KAL gene is responsible for the X-chromosome linked form of Kallmann's syndrome in humans. Upon transfection of CHO cells with a human KAL cDNA, the corresponding encoded protein, KALc, was produced. This protein is N-glycosylated, secreted in the cell culture medium, and is localized at the cell surface. Several lines of evidence indicate that heparan-sulfate chains of proteoglycan(s) are involved in the binding of KALc to the cell membrane. Polyclonal and monoclonal antibodies to the purified KALc were generated. They allowed us to detect and characterize the protein encoded by the KAL gene in the chicken central nervous system at late stages of embryonic development. This protein is synthesized by definite neuronal cell populations including Purkinje cells in the cerebellum, mitral cells in the olfactory bulbs and several subpopulations in the optic tectum and the striatum. The protein, with an approximate molecular mass of 100 kDa, was named anosmin-1 in reference to the deficiency of the sense of smell which characterizes the human disease. Anosmin-1 is likely to be an extracellular matrix component. Since heparin treatment of cell membrane fractions from cerebellum and tectum resulted in the release of the protein, we suggest that one or several heparan-sulfate proteoglycans are involved in the binding of anosmin-1 to the membranes in vivo.


2010 ◽  
Vol 19 (18) ◽  
pp. 3642-3651 ◽  
Author(s):  
Maria M. Alves ◽  
Grzegorz Burzynski ◽  
Jean-Marie Delalande ◽  
Jan Osinga ◽  
Annemieke van der Goot ◽  
...  

Abstract Goldberg–Shprintzen syndrome (GOSHS) is a rare clinical disorder characterized by central and enteric nervous system defects. This syndrome is caused by inactivating mutations in the Kinesin Binding Protein (KBP) gene, which encodes a protein of which the precise function is largely unclear. We show that KBP expression is up-regulated during neuronal development in mouse cortical neurons. Moreover, KBP-depleted PC12 cells were defective in nerve growth factor-induced differentiation and neurite outgrowth, suggesting that KBP is required for cell differentiation and neurite development. To identify KBP interacting proteins, we performed a yeast two-hybrid screen and found that KBP binds almost exclusively to microtubule associated or related proteins, specifically SCG10 and several kinesins. We confirmed these results by validating KBP interaction with one of these proteins: SCG10, a microtubule destabilizing protein. Zebrafish studies further demonstrated an epistatic interaction between KBP and SCG10 in vivo . To investigate the possibility of direct interaction between KBP and microtubules, we undertook co-localization and in vitro binding assays, but found no evidence of direct binding. Thus, our data indicate that KBP is involved in neuronal differentiation and that the central and enteric nervous system defects seen in GOSHS are likely caused by microtubule-related defects.


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