Signalling by the RET receptor tyrosine kinase and its role in the development of the mammalian enteric nervous system

Development ◽  
1999 ◽  
Vol 126 (12) ◽  
pp. 2785-2797 ◽  
Author(s):  
S. Taraviras ◽  
C.V. Marcos-Gutierrez ◽  
P. Durbec ◽  
H. Jani ◽  
M. Grigoriou ◽  
...  
Keyword(s):  
Cell Death ◽  
Nervous System ◽  
Growth Factors ◽  
Tyrosine Kinase ◽  
Enteric Nervous System ◽  
Receptor Tyrosine Kinase ◽  
Enteric Neurons ◽  
Wild Type ◽  
Rat Embryos

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.

scholarly journals Phosphotyrosine 1062 Is Critical for the In Vivo Activity of the Ret9 Receptor Tyrosine Kinase Isoform

2005 ◽  
Vol 25 (21) ◽  
pp. 9661-9673 ◽  
Author(s):  
Adrianne Wong ◽  
Silvia Bogni ◽  
Pille Kotka ◽  
Esther de Graaff ◽  
Vivette D'Agati ◽  
...  
Keyword(s):  
Nervous System ◽  
Amino Acid ◽  
Tyrosine Kinase ◽  
Enteric Nervous System ◽  
Receptor Tyrosine Kinase ◽  
System Development ◽  
Critical Role ◽  
Nervous System Development ◽  
Binding Motif

ABSTRACT The receptor tyrosine kinase Ret plays a critical role in the development of the mammalian excretory and enteric nervous systems. Differential splicing of the primary Ret transcript results in the generation of two main isoforms, Ret9 and Ret51, whose C-terminal amino acid tails diverge after tyrosine (Y) 1062. Monoisoformic mice expressing only Ret9 develop normally and are healthy and fertile. In contrast, animals expressing only Ret51 have aganglionosis of the distal gut and hypoplastic kidneys. By generating monoisoformic mice in which Y1062 of Ret9 has been mutated to phenylalanine, we demonstrate that this amino acid has a critical role in Ret9 signaling that is necessary for the development of the kidneys and the enteric nervous system. These findings argue that the distinct activities of Ret9 and Ret51 result from the differential regulation of Y1062 by C-terminal flanking sequences. However, a mutation which places Y1062 of Ret51 in a Ret9 context improves only marginally the ability of Ret51 to support renal and enteric nervous system development. Finally, monoisoformic mice expressing a variant of Ret9 in which a C-terminal PDZ-binding motif was mutated develop normally and are healthy. Our studies identify Y1062 as a critical regulator of Ret9 signaling and suggest that Ret51-specific motifs are likely to inhibit the activity of this isoform.

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 ◽  
...  
Keyword(s):  
Nervous System ◽  
Enteric Nervous System ◽  
Dynamic Balance ◽  
Neuronal Cell ◽  
Cell Loss ◽  
Enteric Neurons ◽  
Phosphatase And Tensin Homolog ◽  
Tensin Homolog ◽  
Myenteric Ganglia

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.

scholarly journals Primary Cilia Structure Is Prolonged in Enteric Neurons of 5xFAD Alzheimer’s Disease Model Mice

2021 ◽  
Vol 22 (24) ◽  
pp. 13564
Author(s):  
Vu Thu Thuy Nguyen ◽  
Lena Brücker ◽  
Ann-Kathrin Volz ◽  
Julia C. Baumgärtner ◽  
Malena dos Santos Guilherme ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Nervous System ◽  
Neurodegenerative Diseases ◽  
Enteric Nervous System ◽  
Primary Cilium ◽  
Primary Cilia ◽  
Enteric Neurons ◽  
Wild Type ◽  
5Xfad Mice

Neurodegenerative diseases such as Alzheimer’s disease (AD) have long been acknowledged as mere disorders of the central nervous system (CNS). However, in recent years the gut with its autonomous nervous system and the multitude of microbial commensals has come into focus. Changes in gut properties have been described in patients and animal disease models such as altered enzyme secretion or architecture of the enteric nervous system. The underlying cellular mechanisms have so far only been poorly investigated. An important organelle for integrating potentially toxic signals such as the AD characteristic A-beta peptide is the primary cilium. This microtubule-based signaling organelle regulates numerous cellular processes. Even though the role of primary cilia in a variety of developmental and disease processes has recently been recognized, the contribution of defective ciliary signaling to neurodegenerative diseases such as AD, however, has not been investigated in detail so far. The AD mouse model 5xFAD was used to analyze possible changes in gut functionality by organ bath measurement of peristalsis movement. Subsequently, we cultured primary enteric neurons from mutant mice and wild type littermate controls and assessed for cellular pathomechanisms. Neurite mass was quantified within transwell culturing experiments. Using a combination of different markers for the primary cilium, cilia number and length were determined using fluorescence microscopy. 5xFAD mice showed altered gut anatomy, motility, and neurite mass of enteric neurons. Moreover, primary cilia could be demonstrated on the surface of enteric neurons and exhibited an elongated phenotype in 5xFAD mice. In parallel, we observed reduced β-Catenin expression, a key signaling molecule that regulates Wnt signaling, which is regulated in part via ciliary associated mechanisms. Both results could be recapitulated via in vitro treatments of enteric neurons from wild type mice with A-beta. So far, only a few reports on the probable role of primary cilia in AD can be found. Here, we reveal for the first time an architectural altered phenotype of primary cilia in the enteric nervous system of AD model mice, elicited potentially by neurotoxic A-beta. Potential changes on the sub-organelle level—also in CNS-derived neurons—require further investigations.

The STK Receptor Tyrosine Kinase Regulates the Response of Primary Macrophages to LPS in a Ligand-Independent Manner.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3436-3436
Author(s):  
Pamela Correll ◽  
Qingping Liu Liu
Keyword(s):  
Tyrosine Kinase ◽  
Receptor Tyrosine Kinase ◽  
Macrophage Activation ◽  
Endotoxic Shock ◽  
Peritoneal Macrophages ◽  
Dependent Manner ◽  
Wild Type ◽  
Independent Manner ◽  
Retroviral Transduction

Abstract We have shown previously that activation of the STK/RON receptor tyrosine kinase expressed on tissue resident macrophages, by it’s ligand macrophage stimulating protein (MSP), results in the inhibition of NFkB activation, inducible nitric oxide synthase (iNOS) expression and TNFa production, as well as the induction of arginase expression, suggesting a role for this receptor in the regulation of classical vs. alternative macrophage activation. Furthermore, mice with a targeted deletion in this receptor exhibit increased sensitivity to endotoxic shock and DTH responses. More recently, we have demonstrated that MSP stimulation of primary peritoneal macrophages inhibits the production of IL-12. In order to map the domains of STK responsible for the inhibition of classical macrophage activation by MSP, we generated mutant forms of the receptor and expressed wild-type and mutant receptors in primary bone marrow derived macrophages by retroviral transduction. Expression of wild-type STK in these primary cells resulted in the ligand-independent reduction in IL-12p40 production in response to LPS stimulation, which was further inhibited by MSP treatment. This is consistent with the lack of a requirement for MSP in regulating responses to endotoxin in vivo. Surprisingly, a kinase dead receptor, which fails to signal in 293T cells, was fully functional in this assay, suggesting that the kinase activity of the receptor is not required for the inhibition of IL-12p40 under these conditions. However, the docking site tyrosines in the c-terminal tail of the receptor are essential for the inhibition of IL-12p40 by STK, suggesting that STK may be phosphorylated by an another kinase in this system. STK/RON has been shown to associate both physically and functionally with a number of other cell-surface receptors including EpoR, IL-3R bc, EGFR, MET as well as a number of integrins and cadherins. We have shown previously that STK regulates the activity of the aMb2 integrin (CR3) in peritoneal macrophages in a PI3K, PKCz-dependent manner. Here we show that STK also physically associates with CR3, as well as CD14, in RAW264.7 cells in the absence of ligand. Both CR3 and CD14 are capable of directly binding to LPS. Thus, we speculate that STK may exist as part of a receptor complex in macrophages and that signalling through STK might be induced directly by LPS. This would provide a means by which STK could temper the response of tissue-resident macrophages to LPS thereby preventing damage to host tissues.

scholarly journals A Targeting Mutation of Tyrosine 1062 in Ret Causes a Marked Decrease of Enteric Neurons and Renal Hypoplasia

2004 ◽  
Vol 24 (18) ◽  
pp. 8026-8036 ◽  
Author(s):  
Mayumi Jijiwa ◽  
Toshifumi Fukuda ◽  
Kumi Kawai ◽  
Akari Nakamura ◽  
Kei Kurokawa ◽  
...  
Keyword(s):  
Nervous System ◽  
Enteric Nervous System ◽  
Intracellular Signaling ◽  
Effector Proteins ◽  
Mutant Mice ◽  
Enteric Neurons ◽  
Kidney Size ◽  
Renal Hypoplasia ◽  
Deficient Mice

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.

scholarly journals Enteric nervous system can regenerate in zebrafish larva via migration into the ablated area and proliferation of neural crest-derived cells

Development ◽  
2020 ◽  
pp. dev.195339
Author(s):  
Maria Ohno ◽  
Masataka Nikaido ◽  
Natsumi Horiuchi ◽  
Koichi Kawakami ◽  
Kohei Hatta
Keyword(s):  
Nervous System ◽  
Neural Crest ◽  
Enteric Nervous System ◽  
Fluorescent Proteins ◽  
Enteric Neurons ◽  
Regeneration Process ◽  
Congenital Diseases ◽  
Zebrafish Larva ◽  
Brdu Assay

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.

Multipotential progenitors of the mammalian enteric nervous system capable of colonising aganglionic bowel in organ culture

Development ◽  
1999 ◽  
Vol 126 (1) ◽  
pp. 157-168 ◽  
Author(s):  
D. Natarajan ◽  
M. Grigoriou ◽  
C.V. Marcos-Gutierrez ◽  
C. Atkins ◽  
V. Pachnis
Keyword(s):  
Nervous System ◽  
Organ Culture ◽  
Enteric Nervous System ◽  
Culture System ◽  
Culture Conditions ◽  
Wild Type ◽  
Enteric Ganglia ◽  
Mammalian Embryos

The enteric nervous system of vertebrates is derived from neural crest cells that invade the gut wall and generate a highly organised network of enteric ganglia. Among the genes that play an important role in ENS development is c-Ret, mutations of which result in failure of formation of enteric ganglia (intestinal aganglionosis). To further understand the development of the mammalian ENS in general and the mechanism of action of the RET RTK in particular, we have developed and used an organotypic culture system of mouse fetal gut. At the stage of culture initiation, the gut is partially populated by undifferentiated ENS progenitors, but culture for several days results in extensive neuronal and glial differentiation. Using this organ culture system, we have compared the development of the ENS in wild-type and RET-deficient gut and showed that the aganglionic phenotype observed in vivo is consistently reproduced under the in vitro culture conditions. Microinjection of RET+ cells isolated from E11.5 mouse bowel into wild-type or RET-deficient aganglionic gut in organ culture, results in extensive repopulation of their wall by exogenously derived neurons and glia. Finally, using a similar approach, we demonstrate that single RET+ cells introduced into the wall of wild-type gut generate both cell lineages of the ENS, i.e. neurons and glia. Our data show the NC-derived RET+ population of fetal gut in mammalian embryos consists of multipotential progenitors capable of colonising efficiently both wild-type and RET-deficient aganglionic bowel in organ culture.

scholarly journals Zebrafish: A Model Organism for Studying Enteric Nervous System Development and Disease

2021 ◽  
Vol 8 ◽  
Author(s):  
Laura E. Kuil ◽  
Rajendra K. Chauhan ◽  
William W. Cheng ◽  
Robert M. W. Hofstra ◽  
Maria M. Alves
Keyword(s):  
Nervous System ◽  
Neural Crest ◽  
Enteric Nervous System ◽  
Treatment Options ◽  
Model Organism ◽  
Nervous System Development ◽  
Enteric Neurons ◽  
Suitable Model ◽  
Large Network

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.

Requirement of signalling by receptor tyrosine kinase RET for the directed migration of enteric nervous system progenitor cells during mammalian embryogenesis

Development ◽  
2002 ◽  
Vol 129 (22) ◽  
pp. 5151-5160 ◽  
Author(s):  
Dipa Natarajan ◽  
Camelia Marcos-Gutierrez ◽  
Vassilis Pachnis ◽  
Esther de Graaff
Keyword(s):  
Nervous System ◽  
Cell Migration ◽  
Tyrosine Kinase ◽  
Neural Crest ◽  
Enteric Nervous System ◽  
Receptor Tyrosine Kinase ◽  
Neural Crest Cell ◽  
Neural Crest Cell Migration ◽  
Crest Cell

The majority of neurones and glia of the enteric nervous system (ENS) are derived from the vagal neural crest. Shortly after emigration from the neural tube, ENS progenitors invade the anterior foregut and, migrating in a rostrocaudal direction, colonise in an orderly fashion the rest of the foregut, the midgut and the hindgut. We provide evidence that activation of the receptor tyrosine kinase RET by glial cell line-derived neurotrophic factor (GDNF) is required for the directional migration of ENS progenitors towards and within the gut wall. We find that neural crest-derived cells present within foetal small intestine explants migrate towards an exogenous source of GDNF in a RET-dependent fashion. Consistent with an in vivo role of GDNF in the migration of ENS progenitors, we demonstrate that Gdnf is expressed at high levels in the gut of mouse embryos in a spatially and temporally regulated manner. Thus, during invasion of the foregut by vagal-derived neural crest cells, expression of Gdnf was restricted to the mesenchyme of the stomach, ahead of the invading NC cells. Twenty-four hours later and as the ENS progenitors were colonising the midgut,Gdnf expression was upregulated in a more posterior region —the caecum anlage. In further support of a role of endogenous GDNF in enteric neural crest cell migration, we find that in explant cultures GDNF produced by caecum is sufficient to attract NC cells residing in more anterior gut segments. In addition, two independently generated loss-of-function alleles of murine Ret, Ret.k— and miRet51, result in characteristic defects of neural crest cell migration within the developing gut. Finally, we identify phosphatidylinositol-3 kinase and the mitogen-activated protein kinase signalling pathways as playing crucial roles in the migratory response of enteric neural crest cells to GDNF.

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