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Moore E, Zhao R, McKinney MC, Yi K, Wood C, Trainor P. Cell extrusion - a novel mechanism driving neural crest cell delamination. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.09.584232. [PMID: 38559094 PMCID: PMC10979875 DOI: 10.1101/2024.03.09.584232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Neural crest cells (NCC) comprise a heterogeneous population of cells with variable potency, that contribute to nearly every tissue and organ system throughout the body. Considered unique to vertebrates, NCC are transiently generated within the dorsolateral region of the neural plate or neural tube, during neurulation. Their delamination and migration are crucial events in embryo development as the differentiation of NCC is heavily influenced by their final resting locations. Previous work in avian and aquatic species has shown that NCC delaminate via an epithelial-mesenchymal transition (EMT), which transforms these stem and progenitor cells from static polarized epithelial cells into migratory mesenchymal cells with fluid front and back polarity. However, the cellular and molecular drivers facilitating NCC delamination in mammals are poorly understood. We performed live timelapse imaging of NCC delamination in mouse embryos and discovered a group of cells that exit the neuroepithelium as isolated round cells, which then halt for a short period prior to acquiring the mesenchymal migratory morphology classically associated with most delaminating NCC. High magnification imaging and protein localization analyses of the cytoskeleton, together with measurements of pressure and tension of delaminating NCC and neighboring neuroepithelial cells, revealed these round NCC are extruded from the neuroepithelium prior to completion of EMT. Furthermore, we demonstrate that cranial NCC are extruded through activation of the mechanosensitive ion channel, PIEZO1, a key regulator of the live cell extrusion pathway, revealing a new role for PIEZO1 in neural crest cell development. Our results elucidating the cellular and molecular dynamics orchestrating NCC delamination support a model in which high pressure and tension in the neuroepithelium results in activation of the live cell extrusion pathway and delamination of a subpopulation of NCC in parallel with EMT. This model has broad implications for our understanding of cell delamination in development and disease.
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Affiliation(s)
- Emma Moore
- Stowers Institute for Medical Research, Kansas City, MO, USA
| | - Ruonan Zhao
- Stowers Institute for Medical Research, Kansas City, MO, USA
- Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Mary C McKinney
- Stowers Institute for Medical Research, Kansas City, MO, USA
| | - Kexi Yi
- Stowers Institute for Medical Research, Kansas City, MO, USA
| | | | - Paul Trainor
- Stowers Institute for Medical Research, Kansas City, MO, USA
- Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, KS, USA
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2
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Xu Y, Park SH, Gye MC. Head dysgenesis and disruption of cranial neural crest stem cells behaviour by 4-octylphenol in fire-bellied toad Bombina orientalis embryos. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 338:122697. [PMID: 37804908 DOI: 10.1016/j.envpol.2023.122697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 08/18/2023] [Accepted: 10/03/2023] [Indexed: 10/09/2023]
Abstract
Alkylphenolic endocrine disruptors (Eds) have been known to affect development of the descendants of multipotent neural crest cells (NCCs) in amphibian embryos. To unravel the mechanism of head dysgenesis induced by alkylphenols in amphibians, the effect of 4-octylphenol (OP) on the differentiation of cranial NCCs in developing embryos and tadpoles, ex vivo NC explant, and isolated NCCs was examined in fire-bellied toad Bombina orientalis with 0, 1, 2, 5, 10, 25 and 50 μM concentrations. Following OP treatment, head cartilages were frequently absent together with the decreased col2a1 mRNA level in tadpoles. While the lipid hydroperoxide (LPO), endoplasmic reticulum stress (ERS), apoptosis, and DNA fragmentation were significantly increased in stage 22 neulurae and heads of stage 45 tadpoles. In stage 22 neulurae, OP decreased sox9 mRNA, the master transcription factor for chondrogenic differentiation and increased undifferentiated NCC markers. The ectopic NCCs were found in endoderm while mesodermal SOX10(+) cells were decreased. In cranial NCCs isolated from stage 22 embryos, OP treatment decreased cellular survival and increased apoptosis, epithelial-mesenchymal transition (EMT) and cell migration. In chondrogenic induced cranial NC explants, OP treatment decreased SOX9(+) chondrocytes and cartilage development. Together, OP potentiated oxidative damage, apoptosis, EMT, and ectopic migration of NCCs. Considering that tissue differentiation requires stem cells to activate the molecular mechanism of differentiation at the correct location during embryonic development, these changes caused by OP may inhibit sox9-dependent chondrogenic differentiation of cranial NCCs, leading to head dysgenesis in B. orientalis embryos. Therefore, developing multipotent NCCs could be an important target of OP, provides new direction for the estimation of the risk of EDs exposure in human and wildlife animals.
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Affiliation(s)
- Yang Xu
- Department of Life Science and Institute for Natural Sciences, Hanyang University, Seoul, 04763, Republic of Korea
| | - Seung Hyun Park
- Department of Life Science and Institute for Natural Sciences, Hanyang University, Seoul, 04763, Republic of Korea
| | - Myung Chan Gye
- Department of Life Science and Institute for Natural Sciences, Hanyang University, Seoul, 04763, Republic of Korea.
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3
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Zhao R, Trainor PA. Epithelial to mesenchymal transition during mammalian neural crest cell delamination. Semin Cell Dev Biol 2022; 138:54-67. [PMID: 35277330 DOI: 10.1016/j.semcdb.2022.02.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 02/08/2022] [Accepted: 02/21/2022] [Indexed: 11/18/2022]
Abstract
Epithelial to mesenchymal transition (EMT) is a well-defined cellular process that was discovered in chicken embryos and described as "epithelial to mesenchymal transformation" [1]. During EMT, epithelial cells lose their epithelial features and acquire mesenchymal character with migratory potential. EMT has subsequently been shown to be essential for both developmental and pathological processes including embryo morphogenesis, wound healing, tissue fibrosis and cancer [2]. During the past 5 years, interest and study of EMT especially in cancer biology have increased exponentially due to the implied role of EMT in multiple aspects of malignancy such as cell invasion, survival, stemness, metastasis, therapeutic resistance and tumor heterogeneity [3]. Since the process of EMT in embryogenesis and cancer progression shares similar phenotypic changes, core transcription factors and molecular mechanisms, it has been proposed that the initiation and development of carcinoma could be attributed to abnormal activation of EMT factors usually required for normal embryo development. Therefore, developmental EMT mechanisms, whose timing, location, and tissue origin are strictly regulated, could prove useful for uncovering new insights into the phenotypic changes and corresponding gene regulatory control of EMT under pathological conditions. In this review, we initially provide an overview of the phenotypic and molecular mechanisms involved in EMT and discuss the newly emerging concept of epithelial to mesenchymal plasticity (EMP). Then we focus on our current knowledge of a classic developmental EMT event, neural crest cell (NCC) delamination, highlighting key differences in our understanding of NCC EMT between mammalian and non-mammalian species. Lastly, we highlight available tools and future directions to advance our understanding of mammalian NCC EMT.
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Affiliation(s)
- Ruonan Zhao
- Stowers Institute for Medical Research, Kansas City, MO, USA; Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Paul A Trainor
- Stowers Institute for Medical Research, Kansas City, MO, USA; Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, KS, USA.
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4
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Zhang A, Aslam H, Sharma N, Warmflash A, Fakhouri WD. Conservation of Epithelial-to-Mesenchymal Transition Process in Neural Crest Cells and Metastatic Cancer. Cells Tissues Organs 2021; 210:151-172. [PMID: 34218225 DOI: 10.1159/000516466] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 04/12/2021] [Indexed: 11/19/2022] Open
Abstract
Epithelial to mesenchymal transition (EMT) is a highly conserved cellular process in several species, from worms to humans. EMT plays a fundamental role in early embryogenesis, wound healing, and cancer metastasis. For neural crest cell (NCC) development, EMT typically results in forming a migratory and potent cell population that generates a wide variety of cell and tissue, including cartilage, bone, connective tissue, endocrine cells, neurons, and glia amongst many others. The degree of conservation between the signaling pathways that regulate EMT during development and metastatic cancer (MC) has not been fully established, despite ample studies. This systematic review and meta-analysis dissects the major signaling pathways involved in EMT of NCC development and MC to unravel the similarities and differences. While the FGF, TGFβ/BMP, SHH, and NOTCH pathways have been rigorously investigated in both systems, the EGF, IGF, HIPPO, Factor Receptor Superfamily, and their intracellular signaling cascades need to be the focus of future NCC studies. In general, meta-analyses of the associated signaling pathways show a significant number of overlapping genes (particularly ligands, transcription regulators, and targeted cadherins) involved in each signaling pathway of both systems without stratification by body segments and cancer type. Lack of stratification makes it difficult to meaningfully evaluate the intracellular downstream effectors of each signaling pathway. Finally, pediatric neuroblastoma and melanoma are NCC-derived malignancies, which emphasize the importance of uncovering the EMT events that convert NCC into treatment-resistant malignant cells.
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Affiliation(s)
- April Zhang
- Center for Craniofacial Research, Department of Diagnostic and Biomedical Sciences, School of Dentistry, University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Hira Aslam
- Center for Craniofacial Research, Department of Diagnostic and Biomedical Sciences, School of Dentistry, University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Neha Sharma
- Center for Craniofacial Research, Department of Diagnostic and Biomedical Sciences, School of Dentistry, University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Aryeh Warmflash
- Department of Biosciences, Rice University, Houston, Texas, USA
| | - Walid D Fakhouri
- Center for Craniofacial Research, Department of Diagnostic and Biomedical Sciences, School of Dentistry, University of Texas Health Science Center at Houston, Houston, Texas, USA.,Department of Pediatrics, McGovern Medical School, University of Texas Health Science Center, Houston, Texas, USA
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Flach H, Basten T, Schreiner C, Dietmann P, Greco S, Nies L, Roßmanith N, Walter S, Kühl M, Kühl SJ. Retinol binding protein 1 affects Xenopus anterior neural development via all-trans retinoic acid signaling. Dev Dyn 2021; 250:1096-1112. [PMID: 33570783 DOI: 10.1002/dvdy.313] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 01/30/2021] [Accepted: 02/03/2021] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Retinol binding protein 1 (Rbp1) acts as an intracellular regulator of vitamin A metabolism and retinoid transport. In mice, Rbp1 deficiency decreases the capacity of hepatic stellate cells to take up all-trans retinol and sustain retinyl ester stores. Furthermore, Rbp1 is crucial for visual capacity. Although the function of Rbp1 has been studied in the mature eye, its role during early anterior neural development has not yet been investigated in detail. RESULTS We showed that rbp1 is expressed in the eye, anterior neural crest cells (NCCs) and prosencephalon of the South African clawed frog Xenopus laevis. Rbp1 knockdown led to defects in eye formation, including microphthalmia and disorganized retinal lamination, and to disturbed induction and differentiation of the eye field, as shown by decreased rax and pax6 expression. Furthermore, it resulted in reduced rax expression in the prosencephalon and affected cranial cartilage. Rbp1 inhibition also interfered with neural crest induction and migration, as shown by twist and slug. Moreover, it led to a significant reduction of the all-trans retinoic acid target gene pitx2 in NCC-derived periocular mesenchyme. The Rbp1 knockdown phenotypes were rescued by pitx2 RNA co-injection. CONCLUSION Rbp1 is crucial for the development of the anterior neural tissue.
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Affiliation(s)
- Hannah Flach
- Institute of Biochemistry and Molecular Biology, Ulm University, Ulm, Germany
| | - Thomas Basten
- Institute of Biochemistry and Molecular Biology, Ulm University, Ulm, Germany
| | - Corinna Schreiner
- Institute of Biochemistry and Molecular Biology, Ulm University, Ulm, Germany
| | - Petra Dietmann
- Institute of Biochemistry and Molecular Biology, Ulm University, Ulm, Germany
| | - Sara Greco
- Institute of Biochemistry and Molecular Biology, Ulm University, Ulm, Germany
| | - Lea Nies
- Institute of Biochemistry and Molecular Biology, Ulm University, Ulm, Germany
| | - Nathalie Roßmanith
- Institute of Biochemistry and Molecular Biology, Ulm University, Ulm, Germany
| | - Svenja Walter
- Institute of Biochemistry and Molecular Biology, Ulm University, Ulm, Germany
| | - Michael Kühl
- Institute of Biochemistry and Molecular Biology, Ulm University, Ulm, Germany
| | - Susanne J Kühl
- Institute of Biochemistry and Molecular Biology, Ulm University, Ulm, Germany
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6
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Kim CW, Lee SM, Ko EB, Go RE, Jeung EB, Kim MS, Choi KC. Inhibitory effects of cigarette smoke extracts on neural differentiation of mouse embryonic stem cells. Reprod Toxicol 2020; 95:75-85. [PMID: 32454085 DOI: 10.1016/j.reprotox.2020.05.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 05/13/2020] [Accepted: 05/18/2020] [Indexed: 12/24/2022]
Abstract
Maternal smoking during the perinatal period is linked to adverse neonatal outcomes such as low birth weight and birth defects. Numerous studies have shown that cigarette smoke or nicotine exposure has a widespread effect on fetal nerve development. However, there exists a lack of understanding of what specific changes occur at the cellular level on persistent exposure to cigarette smoke during the differentiation of embryonic stem cells (ESCs) into neural cells. We previously investigated the effects of cigarette smoke extract (CSE) and its major component, nicotine, on the neural differentiation of mouse embryonic stem cells (mESCs). Differentiation of mESCs into neural progenitor cells (NPCs) or neural crest cells (NCCs) was induced with chemically defined media, and the cells were continuously exposed to CSE or nicotine during neural differentiation and development. Disturbed balance of the pluripotency state was observed in the NPCs, with consequent inhibition of neurite outgrowth and glial fibrillary acidic protein (Gfap) expression. These inhibitions correlated with the altered expression of proteins involved in the Notch-1 signaling pathways. The migration ability of NCCs was significantly decreased by CSE or nicotine exposure, which was associated with reduced protein expression of migration-related proteins. Taken together, we concluded that CSE and nicotine inhibit differentiation of mESCs into NPCs or NCCs, and may disrupt functional development of neural cells. These results imply that cigarette smoking during the perinatal period potentially inhibits neural differentiation and development of ESCs cells, leading to neonatal abnormal brain development and behavioral abnormalities.
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Affiliation(s)
- Cho-Won Kim
- Laboratory of Biochemistry and Immunology, Republic of Korea
| | - Sung-Moo Lee
- Laboratory of Biochemistry and Immunology, Republic of Korea
| | - Eul-Bee Ko
- Laboratory of Biochemistry and Immunology, Republic of Korea
| | - Ryeo-Eun Go
- Laboratory of Biochemistry and Immunology, Republic of Korea
| | - Eui-Bae Jeung
- Laboratory of Biochemistry and Molecular Biology, College of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk, Republic of Korea
| | - Min-Seok Kim
- Inhalation Toxicology Research Group, Jeonbuk Department of Inhalation Research, Jeongeup, Korea Institute of Toxicology, Jeonbuk, Republic of Korea
| | - Kyung-Chul Choi
- Laboratory of Biochemistry and Immunology, Republic of Korea.
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7
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Jiao YH, Liu M, Wang G, Li HY, Liu JS, Yang X, Yang WD. EMT is the major target for okadaic acid-suppressed the development of neural crest cells in chick embryo. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2019; 180:192-201. [PMID: 31085430 DOI: 10.1016/j.ecoenv.2019.05.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 05/03/2019] [Accepted: 05/05/2019] [Indexed: 06/09/2023]
Abstract
As a main marine phycotoxin, okadaic acid (OA) is mainly responsible for diarrheic shellfish poisoning (DSP), through specifically inhibiting phosphatase (PP1 and PP2A). It has been shown that isotope labelled-OA could cross the placental barrier in mice. However, it remains obscure how OA exposure could affect the formation of neural crest cells (NCCs), especially cranial NCCs in early embryo development. Here, we explored the effects of OA exposure on the generation of neural crest cells during embryonic development using the classic chick embryo model. We found that OA exposure at 100 nM (80.5 μg/L) could cause craniofacial bone defects in the developing chick embryo and delay the development of early chick embryos. Immunofluorescent staining of HNK-1, Pax7, and Ap-2α demonstrated that cranial NCC generation was inhibited by OA exposure. Double immunofluorescent staining with Ap-2α/PHIS3 or Pax7/c-Caspase3 manifested that both NCC proliferation and apoptosis were restrained by OA exposure. Furthermore, the expression of Msx1 and BMP4 were down-regulated in the developing chick embryonic neural tubes, which could contribute the inhibitive production of NCCs. We also discovered that expression of EMT-related adhesion molecules, such as Cadherin 6B (Cad6B) and E-cadherin, was altered following OA exposure. In sum, OA exposure negatively affected the development of embryonic neural crest cells, which in turn might result in cranial bone malformation.
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Affiliation(s)
- Yu-Hu Jiao
- Key Laboratory of Aquatic Eutrophication and Control of Harmful Algal Blooms of Guangdong Higher Education Institute, College of Life Science and Technology, Jinan University, Guangzhou, 510632, China
| | - Meng Liu
- Division of Histology and Embryology, Key Laboratory for Regenerative Medicine of the Ministry of Education, Medical College, Jinan University, Guangzhou, 510632, China
| | - Guang Wang
- Division of Histology and Embryology, Key Laboratory for Regenerative Medicine of the Ministry of Education, Medical College, Jinan University, Guangzhou, 510632, China
| | - Hong-Ye Li
- Key Laboratory of Aquatic Eutrophication and Control of Harmful Algal Blooms of Guangdong Higher Education Institute, College of Life Science and Technology, Jinan University, Guangzhou, 510632, China
| | - Jie-Sheng Liu
- Key Laboratory of Aquatic Eutrophication and Control of Harmful Algal Blooms of Guangdong Higher Education Institute, College of Life Science and Technology, Jinan University, Guangzhou, 510632, China
| | - Xuesong Yang
- Division of Histology and Embryology, Key Laboratory for Regenerative Medicine of the Ministry of Education, Medical College, Jinan University, Guangzhou, 510632, China.
| | - Wei-Dong Yang
- Key Laboratory of Aquatic Eutrophication and Control of Harmful Algal Blooms of Guangdong Higher Education Institute, College of Life Science and Technology, Jinan University, Guangzhou, 510632, China.
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8
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Li J, Perfetto M, Materna C, Li R, Thi Tran H, Vleminckx K, Duncan MK, Wei S. A new transgenic reporter line reveals Wnt-dependent Snai2 re-expression and cranial neural crest differentiation in Xenopus. Sci Rep 2019; 9:11191. [PMID: 31371771 PMCID: PMC6672020 DOI: 10.1038/s41598-019-47665-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 07/19/2019] [Indexed: 02/06/2023] Open
Abstract
During vertebrate embryogenesis, the cranial neural crest (CNC) forms at the neural plate border and subsequently migrates and differentiates into many types of cells. The transcription factor Snai2, which is induced by canonical Wnt signaling to be expressed in the early CNC, is pivotal for CNC induction and migration in Xenopus. However, snai2 expression is silenced during CNC migration, and its roles at later developmental stages remain unclear. We generated a transgenic X. tropicalis line that expresses enhanced green fluorescent protein (eGFP) driven by the snai2 promoter/enhancer, and observed eGFP expression not only in the pre-migratory and migrating CNC, but also the differentiating CNC. This transgenic line can be used directly to detect deficiencies in CNC development at various stages, including subtle perturbation of CNC differentiation. In situ hybridization and immunohistochemistry confirm that Snai2 is re-expressed in the differentiating CNC. Using a separate transgenic Wnt reporter line, we show that canonical Wnt signaling is also active in the differentiating CNC. Blocking Wnt signaling shortly after CNC migration causes reduced snai2 expression and impaired differentiation of CNC-derived head cartilage structures. These results suggest that Wnt signaling is required for snai2 re-expression and CNC differentiation.
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Affiliation(s)
- Jiejing Li
- Department of Biology, West Virginia University, Morgantown, WV, 26506, USA.,Department of Clinical Laboratory, The Affiliated Hospital of KMUST, Medical School, Kunming University of Science and Technology, Kunming, 650032, China
| | - Mark Perfetto
- Department of Biology, West Virginia University, Morgantown, WV, 26506, USA.,Department of Biological Sciences, University of Delaware, Newark, DE, 19716, USA
| | - Christopher Materna
- Department of Biological Sciences, University of Delaware, Newark, DE, 19716, USA
| | - Rebecca Li
- Brown University, Providence, RI, 02912, USA
| | - Hong Thi Tran
- Department for Molecular Biomedical Research and Center for Medical Genetics, Ghent University, B-9052, Ghent, Belgium
| | - Kris Vleminckx
- Department for Molecular Biomedical Research and Center for Medical Genetics, Ghent University, B-9052, Ghent, Belgium
| | - Melinda K Duncan
- Department of Biological Sciences, University of Delaware, Newark, DE, 19716, USA
| | - Shuo Wei
- Department of Biological Sciences, University of Delaware, Newark, DE, 19716, USA.
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9
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Flentke GR, Baulch J, Berres ME, Garic A, Smith SM. Alcohol-mediated calcium signals dysregulate pro-survival Snai2/PUMA/Bcl2 networks to promote p53-mediated apoptosis in avian neural crest progenitors. Birth Defects Res 2019; 111:686-699. [PMID: 31021056 PMCID: PMC7017393 DOI: 10.1002/bdr2.1508] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 02/27/2019] [Accepted: 03/28/2019] [Indexed: 12/12/2022]
Abstract
BACKGROUND Prenatal alcohol exposure causes distinctive craniofacial anomalies that arise, in part, from the apoptotic elimination of neural crest (NC) progenitors that form the face. This vulnerability of NC to alcohol is puzzling as they normally express the transcriptional repressor Snail1/2 (in chick Snai2), which suppresses apoptosis and promotes their migration. Here, we investigate alcohol's impact upon Snai2 function. METHODS Chick cranial NC cells were treated with acute alcohol (52 mM, 2 hr). We evaluated NC migration, gene expression, proliferation, and apoptosis thereafter. RESULTS Transient alcohol exposure induced Snai2 (191% ± 23%; p = .003) and stimulated NC migration (p = .0092). An alcohol-induced calcium transient mediated this Snai2 induction, and BAPTA-AM blocked whereas ionomycin mimicked these pro-migratory effects. Alcohol suppressed CyclinD1 protein content (59.1 ± 12%, p = .007) and NC proliferation (19.7 ± 5.8%, p < .001), but these Snai2-enriched cells still apoptosed in response to alcohol. This was explained because alcohol induced p53 (198 ± 29%, p = .023), and the p53 antagonist pifithrin-α prevented their apoptosis. Moreover, alcohol counteracted Snai2's pro-survival signals, and Bcl2 was repressed (68.5 ± 6.0% of controls, p = .016) and PUMA was not induced, while ATM (1.32-fold, p = .01) and PTEN (1.30-fold, p = .028) were elevated. CONCLUSIONS Alcohol's calcium transient uncouples the Snai2/p53 regulatory loop that normally prevents apoptosis during EMT. This represents a novel pathway in alcohol's neurotoxicity, and complements demonstrations that alcohol suppresses PUMA in mouse NC. We propose that the NCs migratory behavior, and their requirement for Snai2/p53 co-expression, makes them vulnerable to stressors that dysregulate Snai2/p53 interactions, such as alcohol.
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Affiliation(s)
- George R. Flentke
- Nutrition Research Institute, Dept. Nutrition, University of North Carolina at Chapel Hill, Kannapolis NC 28081
- Dept. Nutritional Sciences, University of Wisconsin-Madison, Madison WI 53706
| | - Joshua Baulch
- Nutrition Research Institute, Dept. Nutrition, University of North Carolina at Chapel Hill, Kannapolis NC 28081
| | - Mark E. Berres
- Dept. Nutritional Sciences, University of Wisconsin-Madison, Madison WI 53706
| | - Ana Garic
- Dept. Nutritional Sciences, University of Wisconsin-Madison, Madison WI 53706
| | - Susan M. Smith
- Nutrition Research Institute, Dept. Nutrition, University of North Carolina at Chapel Hill, Kannapolis NC 28081
- Dept. Nutritional Sciences, University of Wisconsin-Madison, Madison WI 53706
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10
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Flach H, Krieg J, Hoffmeister M, Dietmann P, Reusch A, Wischmann L, Kernl B, Riegger R, Oess S, Kühl SJ. Nosip functions during vertebrate eye and cranial cartilage development. Dev Dyn 2018; 247:1070-1082. [PMID: 30055071 DOI: 10.1002/dvdy.24659] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 07/01/2018] [Accepted: 07/13/2018] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND The nitric oxide synthase interacting protein (Nosip) has been associated with diverse human diseases including psychological disorders. In line, early neurogenesis of mouse and Xenopus is impaired upon Nosip deficiency. Nosip knockout mice show craniofacial defects and the down-regulation of Nosip in the mouse and Xenopus leads to microcephaly. Until now, the exact underlying molecular mechanisms of these malformations were still unknown. RESULTS Here, we show that nosip is expressed in the developing ocular system as well as the anterior neural crest cells of Xenopus laevis. Furthermore, Nosip inhibition causes severe defects in eye formation in the mouse and Xenopus. Retinal lamination as well as dorso-ventral patterning of the retina were affected in Nosip-depleted Xenopus embryos. Marker gene analysis using rax, pax6 and otx2 reveals an interference with the eye field induction and differentiation. A closer look on Nosip-deficient Xenopus embryos furthermore reveals disrupted cranial cartilage structures and an inhibition of anterior neural crest cell induction and migration shown by twist, snai2, and egr2. Moreover, foxc1 as downstream factor of retinoic acid signalling is affected upon Nosip deficiency. CONCLUSIONS Nosip is a crucial factor for the development of anterior neural tissue such the eyes and neural crest cells. Developmental Dynamics 247:1070-1082, 2018. © 2018 Wiley Periodicals, Inc.
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Affiliation(s)
- Hannah Flach
- Institute of Biochemistry and Molecular Biology, Ulm University, Ulm, Germany
| | - Julia Krieg
- Institute of Biochemistry and Molecular Biology, Ulm University, Ulm, Germany
| | - Meike Hoffmeister
- Institute of Biochemistry II, Goethe University, Frankfurt Medical School, Frankfurt/Main, Germany.,Institute of Biochemistry, Brandenburg Medical School (MHB) Theodor Fontane, Neuruppin, Germany
| | - Petra Dietmann
- Institute of Biochemistry and Molecular Biology, Ulm University, Ulm, Germany
| | - Adrian Reusch
- Institute of Biochemistry and Molecular Biology, Ulm University, Ulm, Germany
| | - Lisa Wischmann
- Institute of Biochemistry and Molecular Biology, Ulm University, Ulm, Germany
| | - Bianka Kernl
- Institute of Biochemistry and Molecular Biology, Ulm University, Ulm, Germany
| | - Ricarda Riegger
- Institute of Biochemistry and Molecular Biology, Ulm University, Ulm, Germany
| | - Stefanie Oess
- Institute of Biochemistry II, Goethe University, Frankfurt Medical School, Frankfurt/Main, Germany.,Institute of Biochemistry, Brandenburg Medical School (MHB) Theodor Fontane, Neuruppin, Germany
| | - Susanne J Kühl
- Institute of Biochemistry and Molecular Biology, Ulm University, Ulm, Germany
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11
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York JR, Yuan T, Lakiza O, McCauley DW. An ancestral role for Semaphorin3F-Neuropilin signaling in patterning neural crest within the new vertebrate head. Development 2018; 145:dev.164780. [PMID: 29980564 DOI: 10.1242/dev.164780] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Accepted: 06/27/2018] [Indexed: 12/26/2022]
Abstract
The origin of the vertebrate head is one of the great unresolved issues in vertebrate evolutionary developmental biology. Although many of the novelties in the vertebrate head and pharynx derive from the neural crest, it is still unknown how early vertebrates patterned the neural crest within the ancestral body plan they inherited from invertebrate chordates. Here, using a basal vertebrate, the sea lamprey, we show that homologs of Semaphorin3F (Sema3F) ligand and its Neuropilin (Nrp) receptors show complementary and dynamic patterns of expression that correlate with key periods of neural crest development (migration and patterning of cranial neural crest-derived structures). Using CRISPR/Cas9-mediated mutagenesis, we demonstrate that lamprey Sema3F is essential for patterning of neural crest-derived melanocytes, cranial ganglia and the head skeleton, but is not required for neural crest migration or patterning of trunk neural crest derivatives. Based on comparisons with jawed vertebrates, our results suggest that the deployment of Nrp-Sema3F signaling, along with other intercellular guidance cues, was pivotal in allowing early vertebrates to organize and pattern cranial neural crest cells into many of the hallmark structures that define the vertebrate head.
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Affiliation(s)
- Joshua R York
- Department of Biology, University of Oklahoma, 730 Van Vleet Oval, Norman, OK, 73019, USA
| | - Tian Yuan
- Department of Biology, University of Oklahoma, 730 Van Vleet Oval, Norman, OK, 73019, USA
| | - Olga Lakiza
- Department of Biology, University of Oklahoma, 730 Van Vleet Oval, Norman, OK, 73019, USA
| | - David W McCauley
- Department of Biology, University of Oklahoma, 730 Van Vleet Oval, Norman, OK, 73019, USA
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12
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Abstract
The transplantation of cranial neural crest (CNC) expressing green fluorescent protein (GFP) in Xenopus laevis has allowed researchers not only to assess CNC migration in vivo but also to address many other experimental questions. Coupled with loss- or gain-of-function experiments, this technique can be used to characterize the function of specific genes during CNC migration and differentiation. Although targeted injection can also be used to assess gene function during CNC migration, CNC transplantation allows one to answer specific questions, such as whether a gene's function is tissue autonomous, cell autonomous, or exerted in the tissues surrounding the CNC. Here we describe a protocol for performing simple CNC grafts.
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Affiliation(s)
- Hélène Cousin
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, Massachusetts 01003
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13
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Cousin H. Cadherins function during the collective cell migration of Xenopus Cranial Neural Crest cells: revisiting the role of E-cadherin. Mech Dev 2017; 148:79-88. [PMID: 28467887 PMCID: PMC5662486 DOI: 10.1016/j.mod.2017.04.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 04/21/2017] [Accepted: 04/28/2017] [Indexed: 12/20/2022]
Abstract
Collective cell migration is a process whereby cells move while keeping contact with other cells. The Xenopus Cranial Neural Crest (CNC) is a population of cells that emerge during early embryogenesis and undergo extensive migration from the dorsal to ventral part of the embryo's head. These cells migrate collectively and require cadherin mediated cell-cell contact. In this review, we will describe the key features of Xenopus CNC migration including the key molecules driving their migration. We will also review the role of the various cadherins during Xenopus CNC emergence and migration. Lastly, we will discuss the recent and seemingly controversial findings showing that E-cadherin presence is essential for CNC migration.
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Affiliation(s)
- Hélène Cousin
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, MA 01003, United States.
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14
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Deniz E, Jonas S, Hooper M, N. Griffin J, Choma MA, Khokha MK. Analysis of Craniocardiac Malformations in Xenopus using Optical Coherence Tomography. Sci Rep 2017; 7:42506. [PMID: 28195132 PMCID: PMC5307353 DOI: 10.1038/srep42506] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 01/10/2017] [Indexed: 12/17/2022] Open
Abstract
Birth defects affect 3% of children in the United States. Among the birth defects, congenital heart disease and craniofacial malformations are major causes of mortality and morbidity. Unfortunately, the genetic mechanisms underlying craniocardiac malformations remain largely uncharacterized. To address this, human genomic studies are identifying sequence variations in patients, resulting in numerous candidate genes. However, the molecular mechanisms of pathogenesis for most candidate genes are unknown. Therefore, there is a need for functional analyses in rapid and efficient animal models of human disease. Here, we coupled the frog Xenopus tropicalis with Optical Coherence Tomography (OCT) to create a fast and efficient system for testing craniocardiac candidate genes. OCT can image cross-sections of microscopic structures in vivo at resolutions approaching histology. Here, we identify optimal OCT imaging planes to visualize and quantitate Xenopus heart and facial structures establishing normative data. Next we evaluate known human congenital heart diseases: cardiomyopathy and heterotaxy. Finally, we examine craniofacial defects by a known human teratogen, cyclopamine. We recapitulate human phenotypes readily and quantify the functional and structural defects. Using this approach, we can quickly test human craniocardiac candidate genes for phenocopy as a critical first step towards understanding disease mechanisms of the candidate genes.
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Affiliation(s)
- Engin Deniz
- Pediatric Genomics Discovery Program, Department of Pediatrics, Yale University, 333 Cedar Street, New Haven, CT 06510, USA
| | - Stephan Jonas
- Department of Medical Informatics, RWTH Aachen University, Pauwelsstraße 30, 52074 Aachen, Germany
| | - Michael Hooper
- Pediatric Genomics Discovery Program, Department of Pediatrics, Yale University, 333 Cedar Street, New Haven, CT 06510, USA
| | - John N. Griffin
- Pediatric Genomics Discovery Program, Department of Pediatrics, Yale University, 333 Cedar Street, New Haven, CT 06510, USA
| | - Michael A. Choma
- Department of Radiology and Biomedical Imaging, Department of Pediatrics, Yale University, 333 Cedar, Street New Haven, CT 06510, USA
- Department of Biomedical Engineering and Applied Physics, Yale University, 333 Cedar Street, New Haven, CT 06510, USA
| | - Mustafa K. Khokha
- Pediatric Genomics Discovery Program, Department of Pediatrics, Yale University, 333 Cedar Street, New Haven, CT 06510, USA
- Department of Genetics, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
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15
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Perry KJ, Lyons DC, Truchado-Garcia M, Fischer AHL, Helfrich LW, Johansson KB, Diamond JC, Grande C, Henry JQ. Deployment of regulatory genes during gastrulation and germ layer specification in a model spiralian mollusc Crepidula. Dev Dyn 2016. [PMID: 26197970 DOI: 10.1002/dvdy.24308] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND During gastrulation, endoderm and mesoderm are specified from a bipotential precursor (endomesoderm) that is argued to be homologous across bilaterians. Spiralians also generate mesoderm from ectodermal precursors (ectomesoderm), which arises near the blastopore. While a conserved gene regulatory network controls specification of endomesoderm in deuterostomes and ecdysozoans, little is known about genes controlling specification or behavior of either source of spiralian mesoderm or the digestive tract. RESULTS Using the mollusc Crepidula, we examined conserved regulatory factors and compared their expression to fate maps to score expression in the germ layers, blastopore lip, and digestive tract. Many genes were expressed in both ecto- and endomesoderm, but only five were expressed in ectomesoderm exclusively. The latter may contribute to epithelial-to-mesenchymal transition seen in ectomesoderm. CONCLUSIONS We present the first comparison of genes expressed during spiralian gastrulation in the context of high-resolution fate maps. We found variation of genes expressed in the blastopore lip, mouth, and cells that will form the anus. Shared expression of many genes in both mesodermal sources suggests that components of the conserved endomesoderm program were either co-opted for ectomesoderm formation or that ecto- and endomesoderm are derived from a common mesodermal precursor that became subdivided into distinct domains during evolution.
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Affiliation(s)
- Kimberly J Perry
- University of Illinois, Department of Cell and Developmental Biology, Urbana, Illinois
| | | | - Marta Truchado-Garcia
- Departamento de Biología Molecular and Centro de Biología Molecular, "Severo Ochoa" (CSIC, Universidad Autónoma de Madrid), Madrid, Spain
| | - Antje H L Fischer
- Department of Metabolic Biochemistry, Ludwig-Maximilians-University, Munich, Germany.,Marine Biological Laboratory, Woods Hole, Massachusetts
| | | | - Kimberly B Johansson
- Marine Biological Laboratory, Woods Hole, Massachusetts.,Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts
| | | | - Cristina Grande
- Departamento de Biología Molecular and Centro de Biología Molecular, "Severo Ochoa" (CSIC, Universidad Autónoma de Madrid), Madrid, Spain
| | - Jonathan Q Henry
- University of Illinois, Department of Cell and Developmental Biology, Urbana, Illinois
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16
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Yang X, Li J, Zeng W, Li C, Mao B. Elongator Protein 3 (Elp3) stabilizes Snail1 and regulates neural crest migration in Xenopus. Sci Rep 2016; 6:26238. [PMID: 27189455 PMCID: PMC4870573 DOI: 10.1038/srep26238] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Accepted: 04/28/2016] [Indexed: 12/04/2022] Open
Abstract
Elongator protein 3 (Elp3) is the enzymatic unit of the elongator protein complex, a histone acetyltransferase complex involved in transcriptional elongation. It has long been shown to play an important role in cell migration; however, the underlying mechanism is unknown. Here, we showed that Elp3 is expressed in pre-migratory and migrating neural crest cells in Xenopus embryos, and knockdown of Elp3 inhibited neural crest cell migration. Interestingly, Elp3 binds Snail1 through its zinc-finger domain and inhibits its ubiquitination by β-Trcp without interfering with the Snail1/Trcp interaction. We showed evidence that Elp3-mediated stabilization of Snail1 was likely involved in the activation of N-cadherin in neural crest cells to regulate their migratory ability. Our findings provide a new mechanism for the function of Elp3 in cell migration through stabilizing Snail1, a master regulator of cell motility.
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Affiliation(s)
- Xiangcai Yang
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China.,Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, 650203, China
| | - Jiejing Li
- Center of Molecular Diagnostics, The Affiliated Hospital of KMUST, Medical School, Kunming University of Science and Technology, Kunming 650032, China
| | - Wanli Zeng
- China Tobacco Yunnan Industrial Co., Ltd., Kunming, 650024, China
| | - Chaocui Li
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China
| | - Bingyu Mao
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China
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17
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The ribosome biogenesis factor Nol11 is required for optimal rDNA transcription and craniofacial development in Xenopus. PLoS Genet 2015; 11:e1005018. [PMID: 25756904 PMCID: PMC4354908 DOI: 10.1371/journal.pgen.1005018] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Accepted: 01/22/2015] [Indexed: 01/30/2023] Open
Abstract
The production of ribosomes is ubiquitous and fundamental to life. As such, it is surprising that defects in ribosome biogenesis underlie a growing number of symptomatically distinct inherited disorders, collectively called ribosomopathies. We previously determined that the nucleolar protein, NOL11, is essential for optimal pre-rRNA transcription and processing in human tissue culture cells. However, the role of NOL11 in the development of a multicellular organism remains unknown. Here, we reveal a critical function for NOL11 in vertebrate ribosome biogenesis and craniofacial development. Nol11 is strongly expressed in the developing cranial neural crest (CNC) of both amphibians and mammals, and knockdown of Xenopus nol11 results in impaired pre-rRNA transcription and processing, increased apoptosis, and abnormal development of the craniofacial cartilages. Inhibition of p53 rescues this skeletal phenotype, but not the underlying ribosome biogenesis defect, demonstrating an evolutionarily conserved control mechanism through which ribosome-impaired craniofacial cells are removed. Excessive activation of this mechanism impairs craniofacial development. Together, our findings reveal a novel requirement for Nol11 in craniofacial development, present the first frog model of a ribosomopathy, and provide further insight into the clinically important relationship between specific ribosome biogenesis proteins and craniofacial cell survival.
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18
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Tien CL, Jones A, Wang H, Gerigk M, Nozell S, Chang C. Snail2/Slug cooperates with Polycomb repressive complex 2 (PRC2) to regulate neural crest development. Development 2015; 142:722-31. [PMID: 25617436 PMCID: PMC4325378 DOI: 10.1242/dev.111997] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Accepted: 12/11/2014] [Indexed: 12/25/2022]
Abstract
Neural crest cells arise from the border of the neural plate and epidermal ectoderm, migrate extensively and differentiate into diverse cell types during vertebrate embryogenesis. Although much has been learnt about growth factor signals and gene regulatory networks that regulate neural crest development, limited information is available on how epigenetic mechanisms control this process. In this study, we show that Polycomb repressive complex 2 (PRC2) cooperates with the transcription factor Snail2/Slug to modulate neural crest development in Xenopus. The PRC2 core components Eed, Ezh2 and Suz12 are expressed in the neural crest cells and are required for neural crest marker expression. Knockdown of Ezh2, the catalytic subunit of PRC2 for histone H3K27 methylation, results in defects in neural crest specification, migration and craniofacial cartilage formation. EZH2 interacts directly with Snail2, and Snail2 fails to expand the neural crest domains in the absence of Ezh2. Chromatin immunoprecipitation analysis shows that Snail2 regulates EZH2 occupancy and histone H3K27 trimethylation levels at the promoter region of the Snail2 target E-cadherin. Our results indicate that Snail2 cooperates with EZH2 and PRC2 to control expression of the genes important for neural crest specification and migration during neural crest development.
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Affiliation(s)
- Chih-Liang Tien
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, 1720 2nd Avenue S., Birmingham, AL 35294, USA
| | - Amanda Jones
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, 1720 2nd Avenue S., Birmingham, AL 35294, USA
| | - Hengbin Wang
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, 1720 2nd Avenue S., Birmingham, AL 35294, USA
| | - Magda Gerigk
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, 1720 2nd Avenue S., Birmingham, AL 35294, USA
| | - Susan Nozell
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, 1720 2nd Avenue S., Birmingham, AL 35294, USA
| | - Chenbei Chang
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, 1720 2nd Avenue S., Birmingham, AL 35294, USA
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19
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Bisson N, Wedlich D, Moss T. The p21-activated kinase Pak1 regulates induction and migration of the neural crest in Xenopus. Cell Cycle 2014; 11:1316-24. [DOI: 10.4161/cc.19685] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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20
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Chibby functions in Xenopus ciliary assembly, embryonic development, and the regulation of gene expression. Dev Biol 2014; 395:287-98. [PMID: 25220153 DOI: 10.1016/j.ydbio.2014.09.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 09/03/2014] [Accepted: 09/05/2014] [Indexed: 12/21/2022]
Abstract
Wnt signaling and ciliogenesis are core features of embryonic development in a range of metazoans. Chibby (Cby), a basal-body associated protein, regulates β-catenin-mediated Wnt signaling in the mouse but not Drosophila. Here we present an analysis of Cby's embryonic expression and morphant phenotypes in Xenopus laevis. Cby RNA is supplied maternally, negatively regulated by Snail2 but not Twist1, preferentially expressed in the neuroectoderm, and regulates β-catenin-mediated gene expression. Reducing Cby levels reduced the density of multiciliated cells, the number of basal bodies per multiciliated cell, and the numbers of neural tube primary cilia; it also led to abnormal development of the neural crest, central nervous system, and pronephros, all defects that were rescued by a Cby-GFP chimera. Reduction of Cby led to an increase in Wnt8a and decreases in Gli2, Gli3, and Shh RNA levels. Many, but not all, morphant phenotypes were significantly reversed by the Wnt inhibitor SFRP2. These observations extend our understanding of Cby's role in mediating the network of interactions between ciliogenesis, signaling systems and tissue patterning.
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21
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Taneyhill LA, Schiffmacher AT. Cadherin dynamics during neural crest cell ontogeny. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2013; 116:291-315. [PMID: 23481200 DOI: 10.1016/b978-0-12-394311-8.00013-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Cell membrane-associated junctional complexes mediate cell-cell adhesion, intercellular interactions, and other fundamental processes required for proper embryo morphogenesis. Cadherins are calcium-dependent transmembrane proteins at the core of adherens junctions and are expressed in distinct spatiotemporal patterns throughout the development of an important vertebrate cell type, the neural crest. Multipotent neural crest cells arise from the ectoderm as epithelial cells under the influence of inductive cues, undergo an epithelial-to-mesenchymal transition, migrate throughout the embryonic body, and then differentiate into multiple derivatives at predetermined destinations. Neural crest cells change their expressed cadherin repertoires as they undergo each new morphogenetic transition, providing insight into distinct functions of expressed cadherins that are essential for proper completion of each specific stage. Cadherins modulate neural crest cell morphology, segregation, migration, and tissue formation. This chapter reviews the knowledge base of cadherin regulation, expression, and function during the ontogeny of the neural crest.
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Affiliation(s)
- Lisa A Taneyhill
- Department of Animal and Avian Sciences, University of Maryland, 1405 Animal Sciences Center, College Park, Maryland, USA
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22
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Toiyama Y, Yasuda H, Saigusa S, Tanaka K, Inoue Y, Goel A, Kusunoki M. Increased expression of Slug and Vimentin as novel predictive biomarkers for lymph node metastasis and poor prognosis in colorectal cancer. Carcinogenesis 2013; 34:2548-57. [PMID: 24001454 DOI: 10.1093/carcin/bgt282] [Citation(s) in RCA: 106] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Slug and Vimentin genes play a critical role in regulating epithelial-mesenchymal transition (EMT) via downregulation of epithelial markers and upregulation of mesenchymal markers. The present study evaluated the clinical significance of Slug and Vimentin expression as potential disease biomarkers in colorectal cancer (CRC). At first, the biological role of Slug in CRC was assessed by RNA interference in CRC cell lines to assess tumor progression, invasion and migration. Next, we analyzed Slug and Vimentin expression in surgical tissue specimens from 181 CRC patients (Cohort 1) by quantitative real-time reverse transcription-PCR and 208 patients (Cohort 2) by immunohistochemistry. Knockdown of Slug using small interfering RNA in CRC cell lines resulted in inhibition of EMT, reduced cell proliferation, invasion and migration in CRC cells. Interestingly, Slug and Vimentin expression in cancer tissues was significantly higher in patients with higher T stage, lymph node involvement, liver metastasis and advanced tumor node metastasis stages. A significant correlation was observed between Slug and Vimentin expression in CRC (messenger RNA: ρ = 0.546, protein: ρ = 0.405), and increased expression of Slug and Vimentin was significantly associated with poor prognosis. Furthermore, increased expression of Slug emerged as an independent prognostic factor and a predictive marker of lymph node metastasis in CRC patients. Our data provide novel evidence for the biological and clinical significance of Slug and Vimentin expression as potential predictive biomarkers for identifying patients with lymph node metastasis or poor prognosis in CRC.
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Affiliation(s)
- Yuji Toiyama
- Department of Gastrointestinal and Pediatric Surgery, Division of Reparative Medicine, Institute of Life Sciences, Mie University Graduate School of Medicine, Mie 514-8507, Japan and
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23
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Fuentealba J, Toro-Tapia G, Arriagada C, Riquelme L, Beyer A, Henriquez JP, Caprile T, Mayor R, Marcellini S, Hinrichs MV, Olate J, Torrejón M. Ric-8A, a guanine nucleotide exchange factor for heterotrimeric G proteins, is critical for cranial neural crest cell migration. Dev Biol 2013; 378:74-82. [PMID: 23588098 DOI: 10.1016/j.ydbio.2013.04.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Revised: 04/05/2013] [Accepted: 04/05/2013] [Indexed: 01/02/2023]
Abstract
The neural crest (NC) is a transient embryonic structure induced at the border of the neural plate. NC cells extensively migrate towards diverse regions of the embryo, where they differentiate into various derivatives, including most of the craniofacial skeleton and the peripheral nervous system. The Ric-8A protein acts as a guanine nucleotide exchange factor for several Gα subunits, and thus behaves as an activator of signaling pathways mediated by heterotrimeric G proteins. Using in vivo transplantation assays, we demonstrate that Ric-8A levels are critical for the migration of cranial NC cells and their subsequent differentiation into craniofacial cartilage during Xenopus development. NC cells explanted from Ric-8A morphant embryos are unable to migrate directionally towards a source of the Sdf1 peptide, a potent chemoattractant for NC cells. Consistently, Ric-8A knock-down showed anomalous radial migratory behavior, displaying a strong reduction in cell spreading and focal adhesion formation. We further show that during in vivo and in vitro neural crest migration, Ric-8A localizes to the cell membrane, in agreement with its role as a G protein activator. We propose that Ric-8A plays essential roles during the migration of cranial NC cells, possibly by regulating cell adhesion and spreading.
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Affiliation(s)
- Jaime Fuentealba
- Department of Biochemistry and Molecular Biology, Faculty of Biological Sciences, University of Concepcion, Chile
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24
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Kerosuo L, Bronner-Fraser M. What is bad in cancer is good in the embryo: importance of EMT in neural crest development. Semin Cell Dev Biol 2012; 23:320-32. [PMID: 22430756 PMCID: PMC3345076 DOI: 10.1016/j.semcdb.2012.03.010] [Citation(s) in RCA: 103] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Revised: 02/14/2012] [Accepted: 03/01/2012] [Indexed: 11/18/2022]
Abstract
Although the epithelial to mesenchymal transition (EMT) is famous for its role in cancer metastasis, it also is a normal developmental event in which epithelial cells are converted into migratory mesenchymal cells. A prime example of EMT during development occurs when neural crest (NC) cells emigrate from the neural tube thus providing an excellent model to study the principles of EMT in a nonmalignant environment. NC cells start life as neuroepithelial cells intermixed with precursors of the central nervous system. After EMT, they delaminate and begin migrating, often to distant sites in the embryo. While proliferating and maintaining multipotency and cell survival the transitioning neural crest cells lose apicobasal polarity and the basement membrane is broken down. This review discusses how these events are coordinated and regulated, by series of events involving signaling factors, gene regulatory interactions, as well as epigenetic and post-transcriptional modifications. Even though the series of events involved in NC EMT are well known, the sequence in which these steps take place remains a subject of debate, raising the intriguing possibility that, rather than being a single event, neural crest EMT may involve multiple parallel mechanisms.
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Affiliation(s)
- Laura Kerosuo
- Division of Biology, California Institute of Technology, Pasadena, CA 91125, United States
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25
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Harney AS, Meade TJ, LaBonne C. Targeted inactivation of Snail family EMT regulatory factors by a Co(III)-Ebox conjugate. PLoS One 2012; 7:e32318. [PMID: 22393397 PMCID: PMC3290632 DOI: 10.1371/journal.pone.0032318] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2011] [Accepted: 01/26/2012] [Indexed: 01/08/2023] Open
Abstract
Snail family proteins are core EMT (epithelial-mesenchymal transition) regulatory factors that play essential roles in both development and disease processes and have been associated with metastasis in carcinomas. Snail factors are required for the formation of neural crest stem cells in most vertebrate embryos, as well as for the migratory invasive behavior of these cells. Snail factors have recently been linked to the formation of cancer stem cells, and expression of Snail proteins may be associated with tumor recurrence and resistance to chemotherapy and radiotherapy. We report that Co(III)-Ebox is a potent inhibitor of Snail- mediated transcriptional repression in breast cancer cells and in the neural crest of Xenopus. We further show that the activity of Co(III)-Ebox can be modulated by temperature, increasing the utility of this conjugate as a Snail inhibitor in model organisms. We exploit this feature to further delineate the requirements for Snail function during neural crest development, showing that in addition to the roles that Snail factors play in neural crest precursor formation and neural crest EMT/migration, inhibition of Snail function after the onset of neural crest migration leads to a loss of neural crest derived melanocytes. Co(III)-Ebox-mediated inhibition therefore provides a powerful tool for analysing the function of these core EMT factors with unparalleled temporal resolution. Moreover, the potency of Co(III)-Ebox as a Snail inhibitor in breast cancer cells suggests its potential as a therapeutic inhibitor of tumor progression and metastasis.
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Affiliation(s)
- Allison S. Harney
- Department of Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
- Departments of Chemistry, Neurobiology, and Radiology, Northwestern University, Evanston, Illinois, United States of America
| | - Thomas J. Meade
- Department of Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
- Departments of Chemistry, Neurobiology, and Radiology, Northwestern University, Evanston, Illinois, United States of America
- Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Evanston, Illinois, United States of America
| | - Carole LaBonne
- Department of Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
- Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Evanston, Illinois, United States of America
- * E-mail:
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26
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Vandenberg LN, Morrie RD, Adams DS. V-ATPase-dependent ectodermal voltage and pH regionalization are required for craniofacial morphogenesis. Dev Dyn 2011; 240:1889-904. [PMID: 21761475 DOI: 10.1002/dvdy.22685] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Using voltage and pH reporter dyes, we have discovered a never-before-seen regionalization of the Xenopus ectoderm, with cell subpopulations delimited by different membrane voltage and pH. We distinguished three courses of bioelectrical activity. Course I is a wave of hyperpolarization that travels across the gastrula. Course II comprises the appearance of patterns that match shape changes and gene expression domains of the developing face; hyperpolarization marks folding epithelium and both hyperpolarized and depolarized regions overlap domains of head patterning genes. In Course III, localized regions of hyperpolarization form at various positions, expand, and disappear. Inhibiting H(+) -transport by the H(+) -V-ATPase causes abnormalities in: (1) the morphology of craniofacial structures; (2) Course II voltage patterns; and (3) patterns of sox9, pax8, slug, mitf, xfz3, otx2, and pax6. We conclude that this bioelectric signal has a role in development of the face. Thus, it exemplifies an important, under-studied mechanism of developmental regulation.
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Affiliation(s)
- Laura N Vandenberg
- The Tufts Center for Regenerative and Developmental Biology, and Biology Department, Tufts University, Medford, Massachusetts, USA
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Cimadamore F, Fishwick K, Giusto E, Gnedeva K, Cattarossi G, Miller A, Pluchino S, Brill LM, Bronner-Fraser M, Terskikh AV. Human ESC-derived neural crest model reveals a key role for SOX2 in sensory neurogenesis. Cell Stem Cell 2011; 8:538-51. [PMID: 21549328 DOI: 10.1016/j.stem.2011.03.011] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2010] [Revised: 01/26/2011] [Accepted: 03/04/2011] [Indexed: 10/18/2022]
Abstract
The transcription factor SOX2 is widely known to play a critical role in the central nervous system; however, its role in peripheral neurogenesis remains poorly understood. We recently developed an hESC-based model in which migratory cells undergo epithelial to mesenchymal transition (EMT) to acquire properties of neural crest (NC) cells. In this model, we found that migratory NC progenitors downregulate SOX2, but then start re-expressing SOX2 as they differentiate to form neurogenic dorsal root ganglion (DRG)-like clusters. SOX2 downregulation was sufficient to induce EMT and resulted in massive apoptosis when neuronal differentiation was induced. In vivo, downregulation of SOX2 in chick and mouse NC cells significantly reduced the numbers of neurons within DRG. We found that SOX2 binds directly to NGN1 and MASH1 promoters and is required for their expression. Our data suggest that SOX2 plays a key role for NGN1-dependent acquisition of neuronal fates in sensory ganglia.
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Affiliation(s)
- Flavio Cimadamore
- Sanford-Burnham Medical Research Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA.
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Klymkowsky M. Mitochondrial activity, embryogenesis, and the dialogue between the big and little brains of the cell. Mitochondrion 2011; 11:814-9. [DOI: 10.1016/j.mito.2010.11.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2010] [Revised: 11/02/2010] [Accepted: 11/18/2010] [Indexed: 12/31/2022]
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Shi J, Severson C, Yang J, Wedlich D, Klymkowsky MW. Snail2 controls mesodermal BMP/Wnt induction of neural crest. Development 2011; 138:3135-45. [PMID: 21715424 DOI: 10.1242/dev.064394] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The neural crest is an induced tissue that is unique to vertebrates. In the clawed frog Xenopus laevis, neural crest induction depends on signals secreted from the prospective dorsolateral mesodermal zone during gastrulation. The transcription factors Snail2 (Slug), Snail1 and Twist1 are expressed in this region. It is known that Snail2 and Twist1 are required for both mesoderm formation and neural crest induction. Using targeted blastomere injection, morpholino-based loss of function and explant studies, we show that: (1) Snail1 is also required for mesoderm and neural crest formation; (2) loss of snail1, snail2 or twist1 function in the C2/C3 lineage of 32-cell embryos blocks mesoderm formation, but neural crest is lost only in the case of snail2 loss of function; (3) snail2 mutant loss of neural crest involves mesoderm-derived secreted factors and can be rescued synergistically by bmp4 and wnt8 RNAs; and (4) loss of snail2 activity leads to changes in the RNA levels of a number of BMP and Wnt agonists and antagonists. Taken together, these results identify Snail2 as a key regulator of the signals involved in mesodermal induction of neural crest.
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Affiliation(s)
- Jianli Shi
- Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, CO 80309-0347, USA
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30
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Abstract
Cardiac neural crest cells originate as part of the postotic caudal rhombencephalic neural crest stream. Ectomesenchymal cells in this stream migrate to the circumpharyngeal ridge and then into the caudal pharyngeal arches where they condense to form first a sheath and then the smooth muscle tunics of the persisting pharyngeal arch arteries. A subset of the cells continue migrating into the cardiac outflow tract where they will condense to form the aorticopulmonary septum. Cell signaling, extracellular matrix and cell-cell contacts are all critical for the initial migration, pauses, continued migration, and condensation of these cells. This review elucidates what is currently known about these factors.
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RNA interference targeting slug increases cholangiocarcinoma cell sensitivity to cisplatin via upregulating PUMA. Int J Mol Sci 2011; 12:385-400. [PMID: 21339993 PMCID: PMC3039959 DOI: 10.3390/ijms12010385] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2010] [Revised: 01/06/2011] [Accepted: 01/07/2011] [Indexed: 11/17/2022] Open
Abstract
Slug is an E-cadherin repressor and a suppressor of PUMA (p53 upregulated modulator of apoptosis) and it has recently been demonstrated that Slug plays an important role in controlling apoptosis. In this study, we examined whether Slug's ability to silence expression suppresses the growth of cholangiocarcinoma cells and/or sensitizes cholangiocarcinoma cells to chemotherapeutic agents through induction of apoptosis. We targeted the Slug gene using siRNA (Slug siRNA) via full Slug cDNA plasmid (Slug cDNA) transfection of cholangiocarcinoma cells. Slug siRNA, cisplatin, or Slug siRNA in combination with cisplatin, were used to treat cholangiocarcinoma cells in vitro. Western blot was used to detect the expression of Slug, PUMA, and E-cadherin protein. TUNEL, Annexin V Staining, and cell cycle analysis were used to detect apoptosis. A nude mice subcutaneous xenograft model of QBC939 cells was used to assess the effect of Slug silencing and/or cisplatin on tumor growth. Immunohistochemical staining was used to analyze the expression of Slug and PUMA. TUNEL was used to detect apoptosis in vivo. The results showed that PUMA and E-cadherin expression in cholangiocarcinoma cells is Slug dependent. We demonstrated that Slug silencing and cisplatin both promote apoptosis by upregulation of PUMA, not by upregulation of E-cadherin. Slug silencing significantly sensitized cholangiocarcinoma cells to cisplatin through upregulation of PUMA. Finally, we showed that Slug silencing suppressed the growth of QBC939 xenograft tumors and sensitized the tumor cells to cisplatin through PUMA upregulation and induction of apoptosis. Our findings indicate that Slug is an important modulator of the therapeutic response of cholangiocarcinoma cells and is potentially useful as a sensitizer in cholangiocarcinoma therapy. One of the mechanisms is the regulation of PUMA by Slug.
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32
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Schneider M, Schambony A, Wedlich D. Prohibitin1 acts as a neural crest specifier in Xenopus development by repressing the transcription factor E2F1. Development 2010; 137:4073-81. [PMID: 21062864 DOI: 10.1242/dev.053405] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Prohibitin 1 (phb1), which was initially described as an inhibitor of cell proliferation, is a highly conserved protein found in multiple cellular compartments. In the nucleus it interacts with the transcriptional regulators Rb and E2F1 and controls cell proliferation and apoptosis. Here we unravel an unexpected novel function for phb1 in Xenopus cranial neural crest (CNC) development. Xphb1 is maternally expressed; zygotically expressed neurula stage transcripts accumulate in the CNC and the neural tube. Knockdown of Xphb1 by antisense morpholino injection results in the loss of foxD3, snail2 and twist expression, whereas expression of c-myc, AP-2 and snail1 remains unaffected. Xphb2, its closest relative, cannot substitute for Xphb1, underlining the specificity of Xphb1 function. Epistatic analyses place Xphb1 downstream of c-myc and upstream of foxD3, snail2 and twist. To elucidate which subdomain in Xphb1 is required for neural crest gene regulation we generated deletion mutants and tested their rescue ability in Xphb1 morphants. The E2F1-binding domain was found to be necessary for Xphb1 function in neural crest development. Gain- and loss-of-function experiments reveal that Xphb1 represses E2F1 activity; suppression of E2F1 through Xphb1 is required for twist, snail2 and foxD3 expression in the CNC. With the Xphb1 dependency of a subset of CNC specifiers downstream of c-myc, we have identified a new branching point in the neural crest gene regulatory network.
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Affiliation(s)
- Martina Schneider
- KIT, Campus South, Zoologicak Institute, Cell and Developmental Biology, Kaiserstrasse 12, Karlsruhe, Germany
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Alfandari D, Cousin H, Marsden M. Mechanism of Xenopus cranial neural crest cell migration. Cell Adh Migr 2010; 4:553-60. [PMID: 20505318 DOI: 10.4161/cam.4.4.12202] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
This review focuses on recent advances in the field of cranial neural crest cell migration in Xenopus laevis with specific emphasis on cell adhesion and the regulation of cell migration. Our goal is to combine the understanding of cell adhesion to the extracellular matrix with the regulation of cell-cell adhesion and the involvement of the planar cell polarity signaling-pathway in guiding the migration of cranial neural crest cells during embryogenesis.
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Affiliation(s)
- Dominque Alfandari
- Department of Veterinary and Animal Sciences, University of Massachusetts Amherst, USA.
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Klymkowsky MW, Rossi CC, Artinger KB. Mechanisms driving neural crest induction and migration in the zebrafish and Xenopus laevis. Cell Adh Migr 2010; 4:595-608. [PMID: 20962584 PMCID: PMC3011258 DOI: 10.4161/cam.4.4.12962] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2010] [Accepted: 07/09/2010] [Indexed: 01/09/2023] Open
Abstract
The neural crest is an evolutionary adaptation, with roots in the formation of mesoderm. Modification of neural crest behavior has been is critical for the evolutionary diversification of the vertebrates and defects in neural crest underlie a range of human birth defects. There has been a tremendous increase in our knowledge of the molecular, cellular, and inductive interactions that converge on defining the neural crest and determining its behavior. While there is a temptation to look for simple models to explain neural crest behavior, the reality is that the system is complex in its circuitry. In this review, our goal is to identify the broad features of neural crest origins (developmentally) and migration (cellularly) using data from the zebrafish (teleost) and Xenopus laevis (tetrapod amphibian) in order to illuminate where general mechanisms appear to be in play, and equally importantly, where disparities in experimental results suggest areas of profitable study.
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Affiliation(s)
- Michael W Klymkowsky
- Department of Molecular, Cellular and Developmental Biology; University of Colorado Boulder; Boulder, CO USA
| | - Christy Cortez Rossi
- Department of Craniofacial Biology; University of Colorado Denver; School of Dental Medicine; Aurora, CO USA
| | - Kristin Bruk Artinger
- Department of Craniofacial Biology; University of Colorado Denver; School of Dental Medicine; Aurora, CO USA
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Balasubramanian S, Babai N, Chaudhuri A, Qiu F, Bhattacharya S, Dave BJ, Parameswaran S, Carson SD, Thoreson WB, Sharp JG, Rao M, Ahmad I. Non cell-autonomous reprogramming of adult ocular progenitors: generation of pluripotent stem cells without exogenous transcription factors. Stem Cells 2010; 27:3053-62. [PMID: 19859985 DOI: 10.1002/stem.242] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Direct reprogramming of differentiated cells to induced pluripotent stem (iPS) cells by ectopic expression of defined transcription factors (TFs) represents a significant breakthrough towards the use of stem cells in regenerative medicine (Takahashi and Yamanaka Cell 2006;126:663-676). However, the virus-mediated expression of exogenous transcription factors could be potentially harmful and, therefore, represents a barrier to the clinical use of iPS cells. Several approaches, ranging from plasmid-mediated TF expression to introduction of recombinant TFs (Yamanaka Cell 2009;137:13-17; Zhou, Wu, Joo et al. Cell Stem Cell 2009;4:381-384), have been reported to address the risk associated with viral integration. We describe an alternative strategy of reprogramming somatic progenitors entirely through the recruitment of endogenous genes without the introduction of genetic materials or exogenous factors. To this end, we reprogrammed accessible and renewable progenitors from the limbal epithelium of adult rat eye by microenvironment-based induction of endogenous iPS cell genes. Non cell-autonomous reprogramming generates cells that are pluripotent and capable of differentiating into functional neurons, cardiomyocytes, and hepatocytes, which may facilitate autologous cell therapy to treat degenerative diseases.
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Affiliation(s)
- Sudha Balasubramanian
- Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, Nebraska 68198, USA
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36
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Kurauchi T, Izutsu Y, Maéno M. Involvement of Neptune in induction of the hatching gland and neural crest in the Xenopus embryo. Differentiation 2010; 79:251-9. [PMID: 20172647 DOI: 10.1016/j.diff.2010.01.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2009] [Revised: 12/28/2009] [Accepted: 01/31/2010] [Indexed: 11/16/2022]
Abstract
Neptune, a Krüppel-like transcription factor, is expressed in various regions of the developing Xenopus embryo and it has multiple functions in the process of development in various organs. In situ hybridization analysis showed that Neptune is expressed in the boundary region between neural and non-neural tissues at the neurula stage, but little is known about the function of Neptune in this region. Here, we examined the expression and function of Neptune in the neural plate border (NPB) in the Xenopus embryo. Depletion of Neptune protein in developing embryos by using antisense MO caused loss of the hatching gland and otic vesicle as well as malformation of neural crest-derived cranial cartilages and melanocytes. Neptune MO also suppressed the expression of hatching gland and neural crest markers such as he, snail2, sox9 and msx1 at the neurula stage. Subsequent experiments showed that Neptune is necessary and sufficient for the differentiation of hatching gland cells and that it is located downstream of pax3 in the signal regulating the differentiation of these cells. Thus, Neptune is a new member of hatching gland specifier and plays a physiological role in determination and specification of multiple lineages derived from the NPB region.
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Affiliation(s)
- Takayuki Kurauchi
- Graduate School of Science and Technology, Niigata University, 8050 Ikarashi-2, Nishi-ku, Niigata 950-2181, Japan
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37
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Lambertini E, Franceschetti T, Torreggiani E, Penolazzi L, Pastore A, Pelucchi S, Gambari R, Piva R. SLUG: a new target of lymphoid enhancer factor-1 in human osteoblasts. BMC Mol Biol 2010; 11:13. [PMID: 20128911 PMCID: PMC2834684 DOI: 10.1186/1471-2199-11-13] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2009] [Accepted: 02/03/2010] [Indexed: 11/28/2022] Open
Abstract
Background Lymphoid Enhancer Factor-1 (Lef-1) is a member of a transcription factor family that acts as downstream mediator of the Wnt/β-catenin signalling pathway which plays a critical role in osteoblast proliferation and differentiation. In a search for Lef-1 responsive genes in human osteoblasts, we focused on the transcriptional regulation of the SLUG, a zinc finger transcription factor belonging to the Snail family of developmental proteins. Although the role of SLUG in epithelial-mesenchymal transition and cell motility during embryogenesis is well documented, the functions of this factor in most normal adult human tissues are largely unknown. In this study we investigated SLUG expression in normal human osteoblasts and their mesenchymal precursors, and its possible correlation with Lef-1 and Wnt/β-catenin signalling. Results The experiments were performed on normal human primary osteoblasts obtained from bone fragments, cultured in osteogenic conditions in presence of Lef-1 expression vector or GSK-3β inhibitor, SB216763. We demonstrated that the transcription factor SLUG is present in osteoblasts as well as in their mesenchymal precursors obtained from Wharton's Jelly of human umbilical cord and induced to osteoblastic differentiation. We found that SLUG is positively correlated with RUNX2 expression and deposition of mineralized matrix, and is regulated by Lef-1 and β-catenin. Consistently, Chromatin Immunoprecipitation (ChIP) assay, used to detect the direct Lef/Tcf factors that are responsible for the promoter activity of SLUG gene, demonstrated that Lef-1, TCF-1 and TCF4 are recruited to the SLUG gene promoter "in vivo". Conclusion These studies provide, for the first time, the evidence that SLUG expression is correlated with osteogenic commitment, and is positively regulated by Lef-1 signal in normal human osteoblasts. These findings will help to further understand the regulation of the human SLUG gene and reveal the biological functions of SLUG in the context of bone tissue.
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Affiliation(s)
- Elisabetta Lambertini
- Department of Biochemistry and Molecular Biology, Molecular Biology Section, University of Ferrara, Via Fossato di Mortara, 74, 44100 Ferrara, Ferrara, Italy
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38
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39
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Reischauer S, Levesque MP, Nüsslein-Volhard C, Sonawane M. Lgl2 executes its function as a tumor suppressor by regulating ErbB signaling in the zebrafish epidermis. PLoS Genet 2009; 5:e1000720. [PMID: 19911055 PMCID: PMC2771016 DOI: 10.1371/journal.pgen.1000720] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2009] [Accepted: 10/15/2009] [Indexed: 12/18/2022] Open
Abstract
Changes in tissue homeostasis, acquisition of invasive cell characteristics, and tumor formation can often be linked to the loss of epithelial cell polarity. In carcinogenesis, the grade of neoplasia correlates with impaired cell polarity. In Drosophila, lethal giant larvae (lgl), discs large (dlg), and scribble, which are components of the epithelial apico-basal cell polarity machinery, act as tumor suppressors, and orthologs of this evolutionary conserved pathway are lost in human carcinoma with high frequency. However, a mechanistic link between neoplasia and vertebrate orthologs of these tumor-suppressor genes remains to be fully explored at the organismal level. Here, we show that the pen/lgl2 mutant phenotype shares two key cellular and molecular features of mammalian malignancy: cell autonomous epidermal neoplasia and epithelial-to-mesenchymal-transition (EMT) of basal epidermal cells including the differential expression of several regulators of EMT. Further, we found that epidermal neoplasia and EMT in pen/lgl2 mutant epidermal cells is promoted by ErbB signalling, a pathway of high significance in human carcinomas. Intriguingly, EMT in the pen/lgl2 mutant is facilitated specifically by ErbB2 mediated E-cadherin mislocalization and not via canonical snail-dependent down-regulation of E-cadherin expression. Our data reveal that pen/lgl2 functions as a tumor suppressor gene in vertebrates, establishing zebrafish pen/lgl2 mutants as a valuable cancer model.
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Affiliation(s)
- Sven Reischauer
- Max-Planck Institut für Entwicklungsbiologie, Department of Genetics, Tuebingen, Germany
| | - Mitchell P. Levesque
- Max-Planck Institut für Entwicklungsbiologie, Department of Genetics, Tuebingen, Germany
| | | | - Mahendra Sonawane
- Max-Planck Institut für Entwicklungsbiologie, Department of Genetics, Tuebingen, Germany
- * E-mail:
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40
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Targeted inhibition of Snail family zinc finger transcription factors by oligonucleotide-Co(III) Schiff base conjugate. Proc Natl Acad Sci U S A 2009; 106:13667-72. [PMID: 19666616 DOI: 10.1073/pnas.0906423106] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A transition metal complex targeted for the inhibition of a subset of zinc finger transcription factors has been synthesized and tested in Xenopus laevis. A Co(III) Schiff base complex modified with a 17-bp DNA sequence is designed to selectively inhibit Snail family transcription factors. The oligonucleotide-conjugated Co(III) complex prevents Slug, Snail, and Sip1 from binding their DNA targets whereas other transcription factors are still able to interact with their target DNA. The attachment of the oligonucleotide to the Co(III) complex increases specificity 150-fold over the unconjugated complex. Studies demonstrate that neither the oligo, or the Co(III) Schiff base complex alone, are sufficient for inactivation of Slug at concentrations that the conjugated complex mediates inhibition. Slug, Snail, and Sip1 have been implicated in the regulation of epithelial-to-mesenchymal transition in development and cancer. A complex targeted to inactivate their transcriptional activity could prove valuable as an experimental tool and a cancer therapeutic.
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41
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Zhang C, Klymkowsky MW. Unexpected functional redundancy between Twist and Slug (Snail2) and their feedback regulation of NF-kappaB via Nodal and Cerberus. Dev Biol 2009; 331:340-9. [PMID: 19389392 PMCID: PMC2747320 DOI: 10.1016/j.ydbio.2009.04.016] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2008] [Revised: 04/08/2009] [Accepted: 04/09/2009] [Indexed: 10/20/2022]
Abstract
A NF-kappaB-Twist-Snail network controls axis and mesoderm formation in Drosophila. Using translation-blocking morpholinos and hormone-regulated proteins, we demonstrate the presence of an analogous network in the early Xenopus embryo. Loss of twist (twist1) function leads to a reduction of mesoderm and neural crest markers, an increase in apoptosis, and a decrease in snail1 (snail) and snail2 (slug) mRNA levels. Injection of snail2 mRNA rescues twist's loss of function phenotypes and visa versa. In the early embryo NF-kappaB/RelA regulates twist, snail2, and snail1 mRNA levels; similarly Nodal/Smad2 regulate twist, snail2, snail1, and relA RNA levels. Both Twist and Snail2 negatively regulate levels of cerberus RNA, which encodes a Nodal, bone morphogenic protein (BMP), and Wnt inhibitor. Cerberus's anti-Nodal activity inhibits NF-kappaB activity and decreases relA RNA levels. These results reveal both conserved and unexpected regulatory interactions at the core of a vertebrate's mesodermal specification network.
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Affiliation(s)
| | - Michael W. Klymkowsky
- Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, Boulder, CO 80309-0347, U.S.A
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42
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Morokuma J, Blackiston D, Adams DS, Seebohm G, Trimmer B, Levin M. Modulation of potassium channel function confers a hyperproliferative invasive phenotype on embryonic stem cells. Proc Natl Acad Sci U S A 2008; 105:16608-13. [PMID: 18931301 PMCID: PMC2575467 DOI: 10.1073/pnas.0808328105] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2008] [Indexed: 02/07/2023] Open
Abstract
Ion transporters, and the resulting voltage gradients and electric fields, have been implicated in embryonic development and regeneration. These biophysical signals are key physiological aspects of the microenvironment that epigenetically regulate stem and tumor cell behavior. Here, we identify a previously unrecognized function for KCNQ1, a potassium channel known to be involved in human Romano-Ward and Jervell-Lange-Nielsen syndromes when mutated. Misexpression of its modulatory wild-type beta-subunit XKCNE1 in the Xenopus embryo resulted in a striking alteration of the behavior of one type of embryonic stem cell: the pigment cell lineage of the neural crest. Depolarization of embryonic cells by misexpression of KCNE1 non-cell-autonomously induced melanocytes to overproliferate, spread out, and become highly invasive of blood vessels, liver, gut, and neural tube, leading to a deeply hyperpigmented phenotype. This effect is mediated by the up-regulation of Sox10 and Slug genes, thus linking alterations in ion channel function to the control of migration, shape, and mitosis rates during embryonic morphogenesis. Taken together, these data identify a role for the KCNQ1 channel in regulating key cell behaviors and reveal the molecular identity of a biophysical switch, by means of which neoplastic-like properties can be conferred upon a specific embryonic stem cell subpopulation.
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Affiliation(s)
- Junji Morokuma
- *Center for Regenerative and Developmental Biology, Forsyth Institute, and Department of Developmental Biology, Harvard School of Dental Medicine, 140 The Fenway, Boston, MA 02115
| | - Douglas Blackiston
- *Center for Regenerative and Developmental Biology, Forsyth Institute, and Department of Developmental Biology, Harvard School of Dental Medicine, 140 The Fenway, Boston, MA 02115
| | - Dany S. Adams
- *Center for Regenerative and Developmental Biology, Forsyth Institute, and Department of Developmental Biology, Harvard School of Dental Medicine, 140 The Fenway, Boston, MA 02115
| | - Guiscard Seebohm
- Institute of Physiology I, University of Tubingen, 72076 Tubingen, Germany
- Biochemistry I, Ruhr University Bochum, 44780 Bochum, Germany; and
| | - Barry Trimmer
- Department of Biology, Tufts University, Medford, MA 02155
| | - Michael Levin
- *Center for Regenerative and Developmental Biology, Forsyth Institute, and Department of Developmental Biology, Harvard School of Dental Medicine, 140 The Fenway, Boston, MA 02115
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43
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Lamprey snail highlights conserved and novel patterning roles in vertebrate embryos. Dev Genes Evol 2008; 219:31-6. [DOI: 10.1007/s00427-008-0258-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2008] [Accepted: 09/18/2008] [Indexed: 11/26/2022]
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44
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Kuriyama S, Mayor R. Molecular analysis of neural crest migration. Philos Trans R Soc Lond B Biol Sci 2008; 363:1349-62. [PMID: 18198151 DOI: 10.1098/rstb.2007.2252] [Citation(s) in RCA: 141] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The neural crest (NC) cells have been called the 'explorers of the embryos' because they migrate all over the embryo where they differentiate into a variety of diverse kinds of cells. In this work, we analyse the role of different molecules controlling the migration of NC cells. First, we describe the strong similarity between the process of NC migration and metastasis in tumour cells. The epithelial-mesenchymal transition process that both kinds of cells undergo is controlled by the same molecular machinery, including cadherins, connexins, Snail and Twist genes and matrix metalloproteases. Second, we analysed the molecular signals that control the patterned migration of the cephalic and trunk NC cells. Most of the factors described so far, such as Eph/ephrins, semaphorins/neuropilins and Slit/Robo, are negative signals that prohibit the migration of NC cells into target areas of the embryo. Finally, we analyse how the direction of migration is controlled by regulation of cell polarity and how the planar cell polarity or non-canonical Wnt signalling is involved in this process.
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Affiliation(s)
- Sei Kuriyama
- Department of Anatomy and Developmental Biology, University College London, Gower Street, London WC1E 6BT, UK
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45
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Abstract
The transcription factor Yin Yang 1 (YY1) is a multifunctional protein that can activate or repress gene expression depending on the cellular context. YY1 is ubiquitously expressed and highly conserved between species. However, its role varies in diverse cell types and includes proliferation, differentiation, and apoptosis. This review will focus on the function of YY1 in the nervous system including its role in neural development, neuronal function, developmental myelination, and neurological disease. The multiple functions of YY1 in distinct cell types are reviewed and the possible mechanisms underlying the cell specificity for these functions are discussed.
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Affiliation(s)
- Ye He
- Department of Neuroscience and Cell Biology, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, Piscataway, New Jersey, USA.
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46
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Langer EM, Feng Y, Zhaoyuan H, Rauscher FJ, Kroll KL, Longmore GD. Ajuba LIM proteins are snail/slug corepressors required for neural crest development in Xenopus. Dev Cell 2008; 14:424-36. [PMID: 18331720 DOI: 10.1016/j.devcel.2008.01.005] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2007] [Revised: 11/20/2007] [Accepted: 01/09/2008] [Indexed: 01/05/2023]
Abstract
Snail family transcriptional repressors regulate epithelial mesenchymal transitions during physiological and pathological processes. A conserved SNAG repression domain present in all vertebrate Snail proteins is necessary for repressor complex assembly. Here, we identify the Ajuba family of LIM proteins as functional corepressors of the Snail family via an interaction with the SNAG domain. Ajuba LIM proteins interact with Snail in the nucleus on endogenous E-cadherin promoters and contribute to Snail-dependent repression of E-cadherin. Using Xenopus neural crest as a model of in vivo Snail- or Slug-induced EMT, we demonstrate that Ajuba LIM proteins contribute to neural crest development as Snail/Slug corepressors and are required for in vivo Snail/Slug function. Because Ajuba LIM proteins are also components of adherens junctions and contribute to their assembly or stability, their functional interaction with Snail proteins in the nucleus suggests that Ajuba LIM proteins are important regulators of epithelia dynamics communicating surface events with nuclear responses.
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Affiliation(s)
- Ellen M Langer
- Department of Medicine, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA
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Baum B, Settleman J, Quinlan MP. Transitions between epithelial and mesenchymal states in development and disease. Semin Cell Dev Biol 2008; 19:294-308. [PMID: 18343170 DOI: 10.1016/j.semcdb.2008.02.001] [Citation(s) in RCA: 319] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2008] [Accepted: 02/04/2008] [Indexed: 12/21/2022]
Abstract
The ancestors of modern Metazoa were constructed in large part by the foldings and distortions of two-dimensional sheets of epithelial cells. This changed approximately 600 million years ago with the evolution of mesenchymal cells. These cells arise as the result of epithelial cell delamination through a reprogramming process called an epithelial to mesenchymal transition (EMT) [Shook D, Keller R. Mechanisms, mechanics and function of epithelial-mesenchymal transitions in early development. Mech Dev 2003;120:1351-83; Thiery JP, Sleeman JP. Complex networks orchestrate epithelial-mesenchymal transitions. Nat Rev Mol Cell Biol 2006;7:131-42]. Because mesenchymal cells are free to migrate through the body cavity, the evolution of the mesenchyme opened up new avenues for morphological plasticity, as cells evolved the ability to take up new positions within the embryo and to participate in novel cell-cell interactions; forming new types of internal tissues and organs such as muscle and bone [Thiery JP, Sleeman, JP. Complex networks orchestrate epithelial-mesenchymal transitions. Nat Rev Mol Cell Biol 2006;7:131-42; Hay ED, Zuk A. Transformations between epithelium and mesenchyme: normal, pathological, and experimentally induced. Am J Kidney Dis 1995;26:678-90]. After migrating to a suitable site, mesenchymal cells coalesce and re-polarize to form secondary epithelia, in a so-called mesenchymal-epithelial transition (MET). Such switches between mesenchymal and epithelial states are a frequent feature of Metazoan gastrulation [Hay ED, Zuk A. Transformations between epithelium and mesenchyme: normal, pathological, and experimentally induced. Am J Kidney Dis 1995;26:678-90] and the neural crest lineage [Duband JL, Monier F, Delannet M, Newgreen D. Epitheliu-mmesenchyme transition during neural crest development. Acta Anat 1995;154:63-78]. Significantly, however, when hijacked during the development of cancer, the ability of cells to undergo EMT, to leave the primary tumor and to undergo MET at secondary sites can have devastating consequences on the organism, allowing tumor cells derived from epithelia to invade surrounding tissues and spread through the host [Thiery JP, Sleeman JP. Complex networks orchestrate epithelial-mesenchymal transitions. Nat Rev Mol Cell Biol 2006;7:131-42; Hay ED, Zuk A. Transformations between epithelium and mesenchyme: normal, pathological, and experimentally induced. Am J Kidney Dis 1995;26:678-90]. Thus, the molecular and cellular mechanisms underpinning EMT are both an essential feature of Metazoan development and an important area of biomedical research. In this review, we discuss the common molecular and cellular mechanisms involved in EMT in both cases.
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Affiliation(s)
- Buzz Baum
- Department of Cell and Developmental Biology, UCL, London, UK
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Taneyhill LA, Coles EG, Bronner-Fraser M. Snail2 directly represses cadherin6B during epithelial-to-mesenchymal transitions of the neural crest. Development 2007; 134:1481-90. [PMID: 17344227 PMCID: PMC2595139 DOI: 10.1242/dev.02834] [Citation(s) in RCA: 172] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The neural crest, a transient population of migratory cells, forms the craniofacial skeleton and peripheral nervous system, among other derivatives in vertebrate embryos. The transcriptional repressor Snail2 is thought to be crucial for the epithelial-to-mesenchymal transition (EMT) that promotes neural crest delamination from the neural tube; however, little is known about its downstream targets. To this end, we depleted avian Snail2 in the premigratory neural crest using morpholino antisense oligonucleotides and examined effects on potential targets by quantitative PCR. Several dorsal neural tube genes were upregulated by alleviating Snail2 repression; moreover, the cell adhesion molecule cadherin6B was derepressed within 30 minutes of blocking Snail2 translation. Examination of the chick cadherin6B genomic sequence reveals that the regulatory region contains three pairs of clustered E boxes, representing putative Snail2 binding sites. Furthermore, in vivo and in vitro biochemical analyses demonstrate that Snail2 directly binds to these sites and regulates cadherin6B transcription. These results are the first to describe a direct target of Snail2 repression in vivo and in the context of the EMT that characterizes neural crest development.
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Zhang C, Carl TF, Trudeau ED, Simmet T, Klymkowsky MW. An NF-kappaB and slug regulatory loop active in early vertebrate mesoderm. PLoS One 2006; 1:e106. [PMID: 17205110 PMCID: PMC1762408 DOI: 10.1371/journal.pone.0000106] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2006] [Accepted: 11/23/2006] [Indexed: 01/11/2023] Open
Abstract
Background In both Drosophila and the mouse, the zinc finger transcription factor Snail is required for mesoderm formation; its vertebrate paralog Slug (Snai2) appears to be required for neural crest formation in the chick and the clawed frog Xenopus laevis. Both Slug and Snail act to induce epithelial to mesenchymal transition (EMT) and to suppress apoptosis. Methodology & Principle Findings Morpholino-based loss of function studies indicate that Slug is required for the normal expression of both mesodermal and neural crest markers in X. laevis. Both phenotypes are rescued by injection of RNA encoding the anti-apoptotic protein Bcl-xL; Bcl-xL's effects are dependent upon IκB kinase-mediated activation of the bipartite transcription factor NF-κB. NF-κB, in turn, directly up-regulates levels of Slug and Snail RNAs. Slug indirectly up-regulates levels of RNAs encoding the NF-κB subunit proteins RelA, Rel2, and Rel3, and directly down-regulates levels of the pro-apopotic Caspase-9 RNA. Conclusions/Significance These studies reveal a Slug/Snail–NF-κB regulatory circuit, analogous to that present in the early Drosophila embryo, active during mesodermal formation in Xenopus. This is a regulatory interaction of significance both in development and in the course of inflammatory and metastatic disease.
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Affiliation(s)
- Chi Zhang
- Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, Colorado, United States of America
| | - Timothy F. Carl
- Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, Colorado, United States of America
| | - Evan D. Trudeau
- Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, Colorado, United States of America
| | - Thomas Simmet
- Institute of Pharmacology of Natural Products and Clinical Pharmacology, University of Ulm, Ulm, Germany
| | - Michael W. Klymkowsky
- Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, Colorado, United States of America
- * To whom correspondence should be addressed. E-mail:
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Vernon AE, LaBonne C. Slug stability is dynamically regulated during neural crest development by the F-box protein Ppa. Development 2006; 133:3359-70. [PMID: 16887825 DOI: 10.1242/dev.02504] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The neural crest is a population of stem-cell-like precursors found only in vertebrates. Slug, a member of the Snail family of zincfinger transcriptional repressors, is a critical regulator of neural crest development and has also been implicated in the acquisition of invasive behavior during tumor progression. Despite its central role in these two important processes, little is known about the mechanisms that control the expression and/or activity of Slug. We demonstrate that Slug is a labile protein whose stability is positively reinforced through activation of the neural crest regulatory program. We identify Partner of paired (Ppa) as the F-box component of a modular E3 ligase, and show that it is expressed in neural crest-forming regions, and that it binds to and promotes ubiquitin-mediated proteasomal degradation of Slug. Misexpression of Ppa inhibits the formation of neural crest precursors, and Slug mutants in which Ppa binding has been abrogated rescue this inhibition. These results provide novel insight into the regulation of Slug, a protein that plays a central role in neural crest precursor formation, as well as in developmental and pathological epithelial to mesenchymal transitions.
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Affiliation(s)
- Ann E Vernon
- Department of Biochemistry, Molecular Biology and Cell Biology, Northwestern University, Evanston, IL 60208, USA
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