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Liu Y, Luo Z, Xie Y, Sun Y, Yuan F, Jiang L, Lu H, Hu J. Extracellular vesicles from UTX-knockout endothelial cells boost neural stem cell differentiation in spinal cord injury. Cell Commun Signal 2024; 22:155. [PMID: 38424563 PMCID: PMC10903014 DOI: 10.1186/s12964-023-01434-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Accepted: 12/11/2023] [Indexed: 03/02/2024] Open
Abstract
BACKGROUND Vascular endothelial cells are pivotal in the pathophysiological progression following spinal cord injury (SCI). The UTX (Ubiquitously Transcribed Tetratripeptide Repeat on Chromosome X) serves as a significant regulator of endothelial cell phenotype. The manipulation of endogenous neural stem cells (NSCs) offers a compelling strategy for the amelioration of SCI. METHODS Two mouse models were used to investigate SCI: NSCs lineage-traced mice and mice with conditional UTX knockout (UTX KO) in endothelial cells. To study the effects of UTX KO on neural differentiation, we harvested extracellular vesicles (EVs) from both UTX KO spinal cord microvascular endothelial cells (SCMECs) and negative control SCMECs. These EVs were then employed to modulate the differentiation trajectory of endogenous NSCs in the SCI model. RESULTS In our NSCs lineage-traced mice model of SCI, a marked decrease in neurogenesis was observed post-injury. Notably, NSCs in UTX KO SCMECs mice showed enhanced neuronal differentiation compared to controls. RNA sequencing and western blot analyses revealed an upregulation of L1 cell adhesion molecule (L1CAM), a gene associated with neurogenesis, in UTX KO SCMECs and their secreted EVs. This aligns with the observed promotion of neurogenesis in UTX KO conditions. In vivo administration of L1CAM-rich EVs from UTX KO SCMECs (KO EVs) to the mice significantly enhanced neural differentiation. Similarly, in vitro exposure of NSCs to KO EVs resulted in increased activation of the Akt signaling pathway, further promoting neural differentiation. Conversely, inhibiting Akt phosphorylation or knocking down L1CAM negated the beneficial effects of KO EVs on NSC neuronal differentiation. CONCLUSIONS In conclusion, our findings substantiate that EVs derived from UTX KO SCMECs can act as facilitators of neural differentiation following SCI. This study not only elucidates a novel mechanism but also opens new horizons for therapeutic interventions in the treatment of SCI. Video Abstract.
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Affiliation(s)
- Yudong Liu
- Department of Spine Surgery and Orthopaedics, Xiangya Hospital, Central South University, Changsha, China
- Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha, China
- Hunan Engineering Research Center of Sports and Health, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Zixiang Luo
- Department of Spine Surgery and Orthopaedics, Xiangya Hospital, Central South University, Changsha, China
- Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha, China
- Hunan Engineering Research Center of Sports and Health, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Yong Xie
- Department of Spine Surgery and Orthopaedics, Xiangya Hospital, Central South University, Changsha, China
- Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha, China
- Hunan Engineering Research Center of Sports and Health, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Yi Sun
- Department of Spine Surgery and Orthopaedics, Xiangya Hospital, Central South University, Changsha, China
- Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha, China
- Hunan Engineering Research Center of Sports and Health, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Feifei Yuan
- Department of Spine Surgery and Orthopaedics, Xiangya Hospital, Central South University, Changsha, China
- Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha, China
- Hunan Engineering Research Center of Sports and Health, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Liyuan Jiang
- Department of Spine Surgery and Orthopaedics, Xiangya Hospital, Central South University, Changsha, China.
- Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha, China.
- Hunan Engineering Research Center of Sports and Health, Changsha, China.
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China.
| | - Hongbin Lu
- Department of Sports Medicine, Xiangya Hospital, Central South University, Changsha, China.
- Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha, China.
- Hunan Engineering Research Center of Sports and Health, Changsha, China.
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China.
| | - Jianzhong Hu
- Department of Spine Surgery and Orthopaedics, Xiangya Hospital, Central South University, Changsha, China.
- Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha, China.
- Hunan Engineering Research Center of Sports and Health, Changsha, China.
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China.
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Diposarosa R, Bustam NA, Sahiratmadja E, Susanto PS, Sribudiani Y. Literature review: enteric nervous system development, genetic and epigenetic regulation in the etiology of Hirschsprung's disease. Heliyon 2021; 7:e07308. [PMID: 34195419 PMCID: PMC8237298 DOI: 10.1016/j.heliyon.2021.e07308] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 03/16/2021] [Accepted: 06/10/2021] [Indexed: 01/13/2023] Open
Abstract
Hirschsprung's disease (HSCR) is a developmental disorder of the enteric nervous system (ENS) derived from neural crest cells (NCCs), which affects their migration, proliferation, differentiation, or preservation in the digestive tract, resulting in aganglionosis in the distal intestine. The regulation of both NCCs and the surrounding environment involves various genes, signaling pathways, transcription factors, and morphogens. Therefore, changes in gene expression during the development of the ENS may contribute to the pathogenesis of HSCR. This review discusses several mechanisms involved in the development of ENS, confirming that deviant genetic and epigenetic patterns, such as DNA methylation, histone modification, and microRNA (miRNA) regulation, can contribute to the development of neurocristopathy. Specifically, the epigenetic regulation of miRNA expression and its relationship to cellular interactions and gene activation through various major pathways in Hirschsprung's disease will be discussed.
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Affiliation(s)
- R Diposarosa
- Department of Surgery, Division of Pediatric Surgery, Dr. Hasan Sadikin General Hospital, Faculty of Medicine, Universitas Padjadjaran, Bandung, Indonesia
| | - N A Bustam
- Department of Surgery, Division of Pediatric Surgery, Dr. Hasan Sadikin General Hospital, Faculty of Medicine, Universitas Padjadjaran, Bandung, Indonesia
| | - Edhyana Sahiratmadja
- Department of Biomedical Sciences, Division of Biochemistry and Molecular Biology, Faculty of Medicine, Universitas Padjadjaran, Bandung, Indonesia.,Research Center of Medical Genetics, Faculty of Medicine, Universitas Padjadjaran, Bandung, Indonesia
| | - P S Susanto
- Research Center of Medical Genetics, Faculty of Medicine, Universitas Padjadjaran, Bandung, Indonesia
| | - Y Sribudiani
- Department of Biomedical Sciences, Division of Biochemistry and Molecular Biology, Faculty of Medicine, Universitas Padjadjaran, Bandung, Indonesia.,Research Center of Medical Genetics, Faculty of Medicine, Universitas Padjadjaran, Bandung, Indonesia
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Opperman K, Moseley-Alldredge M, Yochem J, Bell L, Kanayinkal T, Chen L. A novel nondevelopmental role of the sax-7/L1CAM cell adhesion molecule in synaptic regulation in Caenorhabditis elegans. Genetics 2015; 199:497-509. [PMID: 25488979 PMCID: PMC4317657 DOI: 10.1534/genetics.114.169581] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 12/02/2014] [Indexed: 01/25/2023] Open
Abstract
The L1CAM family of cell adhesion molecules is a conserved set of single-pass transmembrane proteins that play diverse roles required for proper nervous system development and function. Mutations in L1CAMs can cause the neurological L1 syndrome and are associated with autism and neuropsychiatric disorders. L1CAM expression in the mature nervous system suggests additional functions besides the well-characterized developmental roles. In this study, we demonstrate that the gene encoding the Caenorhabditis elegans L1CAM, sax-7, genetically interacts with gtl-2, as well as with unc-13 and rab-3, genes that function in neurotransmission. These sax-7 genetic interactions result in synthetic phenotypes that are consistent with abnormal synaptic function. Using an inducible sax-7 expression system and pharmacological reagents that interfere with cholinergic transmission, we uncovered a previously uncharacterized nondevelopmental role for sax-7 that impinges on synaptic function.
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Affiliation(s)
- Karla Opperman
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, Minnesota 55455
| | - Melinda Moseley-Alldredge
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, Minnesota 55455 Developmental Biology Center, University of Minnesota, Minneapolis, Minnesota 55455
| | - John Yochem
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, Minnesota 55455
| | - Leslie Bell
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, Minnesota 55455
| | - Tony Kanayinkal
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, Minnesota 55455
| | - Lihsia Chen
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, Minnesota 55455 Developmental Biology Center, University of Minnesota, Minneapolis, Minnesota 55455
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4
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Karunamuni GH, Ma P, Gu S, Rollins AM, Jenkins MW, Watanabe M. Connecting teratogen-induced congenital heart defects to neural crest cells and their effect on cardiac function. BIRTH DEFECTS RESEARCH. PART C, EMBRYO TODAY : REVIEWS 2014; 102:227-50. [PMID: 25220155 PMCID: PMC4238913 DOI: 10.1002/bdrc.21082] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Accepted: 08/26/2014] [Indexed: 12/26/2022]
Abstract
Neural crest cells play many key roles in embryonic development, as demonstrated by the abnormalities that result from their specific absence or dysfunction. Unfortunately, these key cells are particularly sensitive to abnormalities in various intrinsic and extrinsic factors, such as genetic deletions or ethanol-exposure that lead to morbidity and mortality for organisms. This review discusses the role identified for a segment of neural crest in regulating the morphogenesis of the heart and associated great vessels. The paradox is that their derivatives constitute a small proportion of cells to the cardiovascular system. Findings supporting that these cells impact early cardiac function raises the interesting possibility that they indirectly control cardiovascular development at least partially through regulating function. Making connections between insults to the neural crest, cardiac function, and morphogenesis is more approachable with technological advances. Expanding our understanding of early functional consequences could be useful in improving diagnosis and testing therapies.
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Affiliation(s)
- Ganga H. Karunamuni
- Department of Pediatrics, Case Western Reserve University School of Medicine, Case Medical Center Division of Pediatric Cardiology, Rainbow Babies and Children’s Hospital, Cleveland OH 44106
| | - Pei Ma
- Department of Biomedical Engineering, Case Western Reserve University School of Engineering, Cleveland OH 44106
| | - Shi Gu
- Department of Biomedical Engineering, Case Western Reserve University School of Engineering, Cleveland OH 44106
| | - Andrew M. Rollins
- Department of Biomedical Engineering, Case Western Reserve University School of Engineering, Cleveland OH 44106
| | - Michael W. Jenkins
- Department of Pediatrics, Case Western Reserve University School of Medicine, Case Medical Center Division of Pediatric Cardiology, Rainbow Babies and Children’s Hospital, Cleveland OH 44106
- Department of Biomedical Engineering, Case Western Reserve University School of Engineering, Cleveland OH 44106
| | - Michiko Watanabe
- Department of Pediatrics, Case Western Reserve University School of Medicine, Case Medical Center Division of Pediatric Cardiology, Rainbow Babies and Children’s Hospital, Cleveland OH 44106
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5
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Bergner AJ, Stamp LA, Gonsalvez DG, Allison MB, Olson DP, Myers MG, Anderson CR, Young HM. Birthdating of myenteric neuron subtypes in the small intestine of the mouse. J Comp Neurol 2014; 522:514-27. [PMID: 23861145 DOI: 10.1002/cne.23423] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Revised: 06/26/2013] [Accepted: 07/03/2013] [Indexed: 12/31/2022]
Abstract
There are many different types of enteric neurons. Previous studies have identified the time at which some enteric neuron subtypes are born (exit the cell cycle) in the mouse, but the birthdates of some major enteric neuron subtypes are still incompletely characterized or unknown. We combined 5-ethynynl-2'-deoxyuridine (EdU) labeling with antibody markers that identify myenteric neuron subtypes to determine when neuron subtypes are born in the mouse small intestine. We found that different neurochemical classes of enteric neuron differed in their birthdates; serotonin neurons were born first with peak cell cycle exit at E11.5, followed by neurofilament-M neurons, calcitonin gene-related peptide neurons (peak cell cycle exit for both at embryonic day [E]12.5-E13.5), tyrosine hydroxylase neurons (E15.5), nitric oxide synthase 1 (NOS1) neurons (E15.5), and calretinin neurons (postnatal day [P]0). The vast majority of myenteric neurons had exited the cell cycle by P10. We did not observe any EdU+/NOS1+ myenteric neurons in the small intestine of adult mice following EdU injection at E10.5 or E11.5, which was unexpected, as previous studies have shown that NOS1 neurons are present in E11.5 mice. Studies using the proliferation marker Ki67 revealed that very few NOS1 neurons in the E11.5 and E12.5 gut were proliferating. However, Cre-lox-based genetic fate-mapping revealed a small subpopulation of myenteric neurons that appears to express NOS1 only transiently. Together, our results confirm a relationship between enteric neuron subtype and birthdate, and suggest that some enteric neurons exhibit neurochemical phenotypes during development that are different from their mature phenotype.
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Affiliation(s)
- Annette J Bergner
- Department of Anatomy & Neuroscience, University of Melbourne, Victoria, Australia
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6
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Gui H, Bao JY, Tang CSM, So MT, Ngo DN, Tran AQ, Bui DH, Pham DH, Nguyen TL, Tong A, Lok S, Sham PC, Tam PKH, Cherny SS, Garcia-Barcelo MM. Targeted next-generation sequencing on Hirschsprung disease: a pilot study exploits DNA pooling. Ann Hum Genet 2014; 78:381-7. [PMID: 24947032 DOI: 10.1111/ahg.12076] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Accepted: 05/07/2014] [Indexed: 12/11/2022]
Abstract
To adopt an efficient approach of identifying rare variants possibly related to Hirschsprung disease (HSCR), a pilot study was set up to evaluate the performance of a newly designed protocol for next generation targeted resquencing. In total, 20 Chinese HSCR patients and 20 Chinese sex-matched individuals with no HSCR were included, for which coding sequences (CDS) of 62 genes known to be in signaling pathways relevant to enteric nervous system development were selected for capture and sequencing. Blood DNAs from eight pools of five cases or controls were enriched by PCR-based RainDance technology (RDT) and then sequenced on a 454 FLX platform. As technical validation, five patients from case Pool-3 were also independently enriched by RDT, indexed with barcode and sequenced with sufficient coverage. Assessment for CDS single nucleotide variants showed DNA pooling performed well (specificity/sensitivity at 98.4%/83.7%) at the common variant level; but relatively worse (specificity/sensitivity at 65.5%/61.3%) at the rare variant level. Further Sanger sequencing only validated five out of 12 rare damaging variants likely involved in HSCR. Hence more improvement at variant detection and sequencing technology is needed to realize the potential of DNA pooling for large-scale resequencing projects.
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Affiliation(s)
- Hongsheng Gui
- Department of Surgery, The University of Hong Kong, Hong Kong, SAR, China; Department of Psychiatry, The University of Hong Kong, Hong Kong, SAR, China
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Nagaraj K, Mualla R, Hortsch M. The L1 Family of Cell Adhesion Molecules: A Sickening Number of Mutations and Protein Functions. ADVANCES IN NEUROBIOLOGY 2014; 8:195-229. [DOI: 10.1007/978-1-4614-8090-7_9] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Newgreen DF, Dufour S, Howard MJ, Landman KA. Simple rules for a "simple" nervous system? Molecular and biomathematical approaches to enteric nervous system formation and malformation. Dev Biol 2013; 382:305-19. [PMID: 23838398 PMCID: PMC4694584 DOI: 10.1016/j.ydbio.2013.06.029] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Revised: 06/28/2013] [Accepted: 06/28/2013] [Indexed: 11/17/2022]
Abstract
We review morphogenesis of the enteric nervous system from migratory neural crest cells, and defects of this process such as Hirschsprung disease, centering on cell motility and assembly, and cell adhesion and extracellular matrix molecules, along with cell proliferation and growth factors. We then review continuum and agent-based (cellular automata) models with rules of cell movement and logistical proliferation. Both movement and proliferation at the individual cell level are modeled with stochastic components from which stereotyped outcomes emerge at the population level. These models reproduced the wave-like colonization of the intestine by enteric neural crest cells, and several new properties emerged, such as colonization by frontal expansion, which were later confirmed biologically. These models predict a surprising level of clonal heterogeneity both in terms of number and distribution of daughter cells. Biologically, migrating cells form stable chains made up of unstable cells, but this is not seen in the initial model. We outline additional rules for cell differentiation into neurons, axon extension, cell-axon and cell-cell adhesions, chemotaxis and repulsion which can reproduce chain migration. After the migration stage, the cells re-arrange as a network of ganglia. Changes in cell adhesion molecules parallel this, and we describe additional rules based on Steinberg's Differential Adhesion Hypothesis, reflecting changing levels of adhesion in neural crest cells and neurons. This was able to reproduce enteric ganglionation in a model. Mouse mutants with disturbances of enteric nervous system morphogenesis are discussed, and these suggest future refinement of the models. The modeling suggests a relatively simple set of cell behavioral rules could account for complex patterns of morphogenesis. The model has allowed the proposal that Hirschsprung disease is mostly an enteric neural crest cell proliferation defect, not a defect of cell migration. In addition, the model suggests an explanations for zonal and skip segment variants of Hirschsprung disease, and also gives a novel stochastic explanation for the observed discordancy of Hirschsprung disease in identical twins.
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Affiliation(s)
- Donald F Newgreen
- The Murdoch Children's Research Institute, Royal Children's Hospital, Parkville, VIC 3052, Australia.
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9
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Obermayr F, Hotta R, Enomoto H, Young HM. Development and developmental disorders of the enteric nervous system. Nat Rev Gastroenterol Hepatol 2013; 10:43-57. [PMID: 23229326 DOI: 10.1038/nrgastro.2012.234] [Citation(s) in RCA: 140] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The enteric nervous system (ENS) arises from neural crest-derived cells that migrate into and along the gut, leading to the formation of a complex network of neurons and glial cells that regulates motility, secretion and blood flow. This Review summarizes the progress made in the past 5 years in our understanding of ENS development, including the migratory pathways of neural crest-derived cells as they colonize the gut. The importance of interactions between neural crest-derived cells, between signalling pathways and between developmental processes (such as proliferation and migration) in ensuring the correct development of the ENS is also presented. The signalling pathways involved in ENS development that were determined using animal models are also described, as is the evidence for the involvement of the genes encoding these molecules in Hirschsprung disease-the best characterized paediatric enteric neuropathy. Finally, the aetiology and treatment of Hirschsprung disease in the clinic and the potential involvement of defects in ENS development in other paediatric motility disorders are outlined.
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Affiliation(s)
- Florian Obermayr
- Department of Pediatric Surgery, University Children's Hospital, University of Tübingen, Hoppe-Seyler Straße 3, Tübingen 72076, Germany
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Wallace AS, Tan MX, Schachner M, Anderson RB. L1cam acts as a modifier gene for members of the endothelin signalling pathway during enteric nervous system development. Neurogastroenterol Motil 2011; 23:e510-22. [PMID: 21395909 DOI: 10.1111/j.1365-2982.2011.01692.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND The enteric nervous system originates from neural crest cells that migrate into the embryonic foregut and then sequentially colonize the midgut and hindgut. Defects in neural crest migration result in regions of the gut that lack enteric ganglia, a condition in humans called Hirschsprung's disease. The high degree of phenotypic variability reported in Hirschsprung's disease suggests the involvement of modifier genes. METHODS We used a two-locus complementation approach to screen for genetic interactions between L1cam and members of the endothelin signalling pathway. Immunohistochemistry was used to label PGP9.5(+) enteric neurons and Sox10(+) neural crest-derived cells in wholemount preparations of embryonic gut. Key Results Loss or haploinsufficiency of L1cam significantly increased the severity of aganglionosis in Et-3 and Ednrb null mutant embryos. Furthermore, the colonization of the developing gut by neural crest-derived cells was significantly delayed in L1cam(-/y) ; Et-3(-/-) and L1cam(-/y) ;Ednrb(sl/sl) embryos. CONCLUSIONS & INFERENCES We have identified the X-linked gene, L1cam, as the first modifier gene for members of the endothelin signalling pathway during development of the enteric nervous system. Mutations in L1CAM may act to modulate the severity of aganglionosis in some cases of Hirschsprung's disease.
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Affiliation(s)
- A S Wallace
- Department of Anatomy and Cell Biology, University of Melbourne, Parkville, Melbourne, Victoria, Australia
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11
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L1cam acts as a modifier gene during enteric nervous system development. Neurobiol Dis 2010; 40:622-33. [PMID: 20696247 DOI: 10.1016/j.nbd.2010.08.006] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2010] [Revised: 07/21/2010] [Accepted: 08/03/2010] [Indexed: 12/13/2022] Open
Abstract
The enteric nervous system is derived from neural crest cells that migrate from the caudal hindbrain and colonise the gut. Failure of neural crest cells to fully colonise the gut results in an "aganglionic zone" that lacks a functional enteric nervous system over a variable length of the distal bowel, a condition in human infants known as Hirschsprung's disease. The variability observed in the penetrance and severity of Hirschsprung's disease suggests a role for modifier genes. Clinical studies have identified a population of Hirschsprung's patients with mutations in L1CAM that also have a common polymorphism in RET, suggesting a possible interaction between L1CAM and RET. Therefore, we examined whether L1cam could interact with Ret, its ligand Gdnf, and a known transcriptional activator of Ret, Sox10. Using a two-locus complementation approach, we show that loss of L1cam in conjunction with a heterozygous loss of Ret or Gdnf did not result in aganglionosis. However, L1cam did interact with Sox10 to significantly increase the incidence of aganglionosis. We show that an interaction between L1cam and Sox10 significantly perturbs neural crest migration within the developing gut, and that neural crest cells undergo excessive cell death prior to gut entry. Finally, we show that Sox10 can regulate the expression of L1cam. Thus, L1cam can act as a modifier gene for the HSCR associated gene, Sox10, and is likely to play a role in the etiology of Hirschsprung's disease.
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Schäfer MKE, Altevogt P. L1CAM malfunction in the nervous system and human carcinomas. Cell Mol Life Sci 2010; 67:2425-37. [PMID: 20237819 PMCID: PMC11115577 DOI: 10.1007/s00018-010-0339-1] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2009] [Revised: 01/30/2010] [Accepted: 02/11/2010] [Indexed: 12/14/2022]
Abstract
Research over the last 25 years on the cell adhesion molecule L1 has revealed its pivotal role in nervous system function. Mutations of the human L1CAM gene have been shown to cause neurodevelopmental disorders such as X-linked hydrocephalus, spastic paraplegia and mental retardation. Impaired L1 function has been also implicated in the aetiology of fetal alcohol spectrum disorders, defective enteric nervous system development and malformations of the renal system. Importantly, aberrant expression of L1 has emerged as a critical factor in the development of human carcinomas, where it enhances cell proliferation, motility and chemoresistance. This discovery promoted collaborative work between tumour biologists and neurobiologists, which has led to a substantial expansion of the basic knowledge about L1 function and regulation. Here we provide an overview of the pathological conditions caused by L1 malfunction. We further discuss how the available data on gene regulation, molecular interactions and posttranslational processing of L1 may contribute to a better understanding of associated neurological and cancerous diseases.
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Affiliation(s)
- Michael K E Schäfer
- Center for Neurosciences, Institute of Anatomy and Cell Biology, University of Freiburg, Freiburg, Germany.
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13
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Hao MM, Moore RE, Roberts RR, Nguyen T, Furness JB, Anderson RB, Young HM. The role of neural activity in the migration and differentiation of enteric neuron precursors. Neurogastroenterol Motil 2010; 22:e127-37. [PMID: 20082666 DOI: 10.1111/j.1365-2982.2009.01462.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND As they migrate through the developing gut, a sub-population of enteric neural crest-derived cells (ENCCs) begins to differentiate into neurons. The early appearance of neurons raises the possibility that electrical activity and neurotransmitter release could influence the migration or differentiation of ENNCs. METHODS The appearance of neuronal sub-types in the gut of embryonic mice was examined using immunohistochemistry. The effects of blocking various forms of neural activity on ENCC migration and neuronal differentiation were examined using explants of cultured embryonic gut. KEY RESULTS Nerve fibers were present in close apposition to many ENCCs. Commencing at E11.5, neuronal nitric oxide synthase (nNOS), calbindin and IK(Ca) channel immunoreactivities were shown by sub-populations of enteric neurons. In cultured explants of embryonic gut, tetrodotoxin (TTX, an inhibitor of action potential generation), nitro-L-arginine (NOLA, an inhibitor of nitric oxide synthesis) and clotrimazole (an IK(Ca) channel blocker) did not affect the rate of ENCC migration, but tetanus toxin (an inhibitor of SNARE-mediated vesicle fusion) significantly impaired ENCC migration as previously reported. In explants of E11.5 and E12.5 hindgut grown in the presence of TTX or tetanus toxin there was a decrease in the number nNOS+ neurons close to the migratory wavefront, but no significant difference in the proportion of all ENCC that expressed the pan-neuronal marker, Hu. CONCLUSIONS & INFERENCES (i) Some enteric neuron sub-types are present very early during the development of the enteric nervous system. (ii) The rate of differentiation of some sub-types of enteric neurons appears to be influenced by TTX- and tetanus toxin-sensitive mechanisms.
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Affiliation(s)
- M M Hao
- Department of Anatomy & Cell Biology, University of Melbourne, Vic., Australia
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14
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Abstract
The mature enteric nervous system (ENS) is composed of many different neuron subtypes and enteric glia, which all arise from the neural crest. How this diversity is generated from neural crest-derived cells is a central question in neurogastroenterology, as defects in these processes are likely to underlie some paediatric motility disorders. Here we review the developmental appearance (the earliest age at which expression of specific markers can be localized) and birthdates (the age at which precursors exit the cell cycle) of different enteric neuron subtypes, and their projections to some targets. We then focus on what is known about the mechanisms underlying the generation of enteric neuron diversity and axon pathfinding. Finally, we review the development of the ENS in humans and the etiologies of a number of paediatric motility disorders.
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Affiliation(s)
- Marlene M Hao
- Department of Anatomy & Cell Biology, University of MelbourneParkville, Victoria, Australia
| | - Heather M Young
- Department of Anatomy & Cell Biology, University of MelbourneParkville, Victoria, Australia
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